On 04/12/2023 17:33, Boris Brezillon wrote:
> MMU and VM management is related and placed in the same source file.
>
> Page table updates are delegated to the io-pgtable-arm driver that's in
> the iommu subsystem.
>
> The VM management logic is based on drm_gpuva_mgr, and is assuming the
> VA space is mostly managed by the usermode driver, except for a reserved
> portion of this VA-space that's used for kernel objects (like the heap
> contexts/chunks).
>
> Both asynchronous and synchronous VM operations are supported, and
> internal helpers are exposed to allow other logical blocks to map their
> buffers in the GPU VA space.
>
> There's one VM_BIND queue per-VM (meaning the Vulkan driver can only
> expose one sparse-binding queue), and this bind queue is managed with
> a 1:1 drm_sched_entity:drm_gpu_scheduler, such that each VM gets its own
> independent execution queue, avoiding VM operation serialization at the
> device level (things are still serialized at the VM level).
>
> The rest is just implementation details that are hopefully well explained
> in the documentation.
>
> v3:
> - Add acks for the MIT/GPL2 relicensing
> - Propagate MMU faults to the scheduler
> - Move pages pinning/unpinning out of the dma_signalling path
> - Fix 32-bit support
> - Rework the user/kernel VA range calculation
> - Make the auto-VA range explicit (auto-VA range doesn't cover the full
> kernel-VA range on the MCU VM)
> - Let callers of panthor_vm_alloc_va() allocate the drm_mm_node
> (embedded in panthor_kernel_bo now)
> - Adjust things to match the latest drm_gpuvm changes (extobj tracking,
> resv prep and more)
> - Drop the per-AS lock and use slots_lock (fixes a race on vm->as.id)
> - Set as.id to -1 when reusing an address space from the LRU list
> - Drop misleading comment about page faults
> - Remove check for irq being assigned in panthor_mmu_unplug()
>
> Signed-off-by: Boris Brezillon <boris.brezil...@collabora.com>
> Signed-off-by: Steven Price <steven.pr...@arm.com>
> Acked-by: Steven Price <steven.pr...@arm.com> # MIT+GPL2 relicensing,Arm
> Acked-by: Grant Likely <grant.lik...@linaro.org> # MIT+GPL2 relicensing,Linaro
> Acked-by: Boris Brezillon <boris.brezil...@collabora.com> # MIT+GPL2
> relicensing,Collabora
A few comments below, but nothing major.
> ---
> drivers/gpu/drm/panthor/panthor_mmu.c | 2653 +++++++++++++++++++++++++
> drivers/gpu/drm/panthor/panthor_mmu.h | 101 +
> 2 files changed, 2754 insertions(+)
> create mode 100644 drivers/gpu/drm/panthor/panthor_mmu.c
> create mode 100644 drivers/gpu/drm/panthor/panthor_mmu.h
>
> diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c
> b/drivers/gpu/drm/panthor/panthor_mmu.c
> new file mode 100644
> index 000000000000..e6c278e8cf35
> --- /dev/null
> +++ b/drivers/gpu/drm/panthor/panthor_mmu.c
> @@ -0,0 +1,2653 @@
> +// SPDX-License-Identifier: GPL-2.0 or MIT
> +/* Copyright 2019 Linaro, Ltd, Rob Herring <r...@kernel.org> */
> +/* Copyright 2023 Collabora ltd. */
> +
> +#include <drm/drm_debugfs.h>
> +#include <drm/drm_drv.h>
> +#include <drm/drm_exec.h>
> +#include <drm/drm_gpuvm.h>
> +#include <drm/drm_managed.h>
> +#include <drm/gpu_scheduler.h>
> +#include <drm/panthor_drm.h>
> +
> +#include <linux/atomic.h>
> +#include <linux/bitfield.h>
> +#include <linux/delay.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/iopoll.h>
> +#include <linux/io-pgtable.h>
> +#include <linux/iommu.h>
> +#include <linux/kmemleak.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/rwsem.h>
> +#include <linux/sched.h>
> +#include <linux/shmem_fs.h>
> +#include <linux/sizes.h>
> +
> +#include "panthor_device.h"
> +#include "panthor_heap.h"
> +#include "panthor_mmu.h"
> +#include "panthor_sched.h"
> +#include "panthor_gem.h"
> +#include "panthor_regs.h"
> +
> +#define MAX_AS_SLOTS 32
> +
> +struct panthor_vm;
> +
> +/**
> + * struct panthor_as_slot - Address space slot
> + */
> +struct panthor_as_slot {
> + /** @vm: VM bound to this slot. NULL is no VM is bound. */
> + struct panthor_vm *vm;
> +};
> +
> +/**
> + * struct panthor_mmu - MMU related data
> + */
> +struct panthor_mmu {
> + /** @irq: The MMU irq. */
> + struct panthor_irq irq;
> +
> + /** @as: Address space related fields.
> + *
> + * The GPU has a limited number of address spaces (AS) slots, forcing
> + * us to re-assign them to re-assign slots on-demand.
> + */
> + struct {
> + /** @slots_lock: Lock protecting access to all other AS fields.
> */
> + struct mutex slots_lock;
> +
> + /** @alloc_mask: Bitmask encoding the allocated slots. */
> + unsigned long alloc_mask;
> +
> + /** @faulty_mask: Bitmask encoding the faulty slots. */
> + unsigned long faulty_mask;
> +
> + /** @slots: VMs currently bound to the AS slots. */
> + struct panthor_as_slot slots[MAX_AS_SLOTS];
> +
> + /**
> + * @lru_list: List of least recently used VMs.
> + *
> + * We use this list to pick a VM to evict when all slots are
> + * used.
> + *
> + * There should be no more active VMs than there are AS slots,
> + * so this LRU is just here to keep VMs bound until there's
> + * a need to release a slot, thus avoid unnecessary TLB/cache
> + * flushes.
> + */
> + struct list_head lru_list;
> + } as;
> +
> + /** @vm: VMs management fields */
> + struct {
> + /** @lock: Lock protecting access to list. */
> + struct mutex lock;
> +
> + /** @list: List containing all VMs. */
> + struct list_head list;
> +
> + /** @reset_in_progress: True if a reset is in progress. */
> + bool reset_in_progress;
> +
> + /** @wq: Workqueue used for the VM_BIND queues. */
> + struct workqueue_struct *wq;
> + } vm;
> +};
> +
> +/**
> + * struct panthor_vm_pool - VM pool object
> + */
> +struct panthor_vm_pool {
> + /** @xa: Array used for VM handle tracking. */
> + struct xarray xa;
> +};
> +
> +/**
> + * struct panthor_vma - GPU mapping object
> + *
> + * This is used to track GEM mappings in GPU space.
> + */
> +struct panthor_vma {
> + /** @base: Inherits from drm_gpuva. */
> + struct drm_gpuva base;
> +
> + /** @node: Used to implement deferred release of VMAs. */
> + struct list_head node;
> +
> + /**
> + * @flags: Combination of drm_panthor_vm_bind_op_flags.
> + *
> + * Only map related flags are accepted.
> + */
> + u32 flags;
> +};
> +
> +/**
> + * struct panthor_vm_op_ctx - VM operation context
> + *
> + * With VM operations potentially taking place in a dma-signaling path, we
> + * need to make sure everything that might require resource allocation is
> + * pre-allocated upfront. This is what this operation context is far.
> + *
> + * We also collect resources that have been freed, so we can release them
> + * asynchronously, and let the VM_BIND scheduler process the next VM_BIND
> + * request.
> + */
> +struct panthor_vm_op_ctx {
> + /** @rsvd_page_tables: Pages reserved for the MMU page table update. */
> + struct {
> + /** @count: Number of pages reserved. */
> + u32 count;
> +
> + /** @ptr: Point to the first unused page in the @pages table. */
> + u32 ptr;
> +
> + /**
> + * @page: Array of pages that can be used for an MMU page table
> update.
> + *
> + * After an VM operation, there might be free pages left in
> this array.
> + * They should be returned to the pt_cache as part of the
> op_ctx cleanup.
> + */
> + void **pages;
> + } rsvd_page_tables;
> +
> + /** @flags: Combination of drm_panthor_vm_bind_op_flags. */
> + u32 flags;
> +
> + /** @va: Virtual range targeted by the VM operation. */
> + struct {
> + /** @addr: Start address. */
> + u64 addr;
> +
> + /** @range: Range size. */
> + u64 range;
> + } va;
> +
> + /**
> + * @returned_vmas: List of panthor_vma objects returned after a VM
> operation.
> + *
> + * For unmap operations, this will contain all VMAs that were covered
> by the
> + * specified VA range.
> + *
> + * For map operations, this will contain all VMAs that previously
> mapped to
> + * the specified VA range.
> + *
> + * Those VMAs, and the resources they point to will be released as part
> of
> + * the op_ctx cleanup operation.
> + */
> + struct list_head returned_vmas;
> +
> + /** @map: Fields specific to a map operation. */
> + struct {
> + /** @vm_bo: Buffer object to map. */
> + struct drm_gpuvm_bo *vm_bo;
> +
> + /** @bo_offset: Offset in the buffer object. */
> + u64 bo_offset;
> +
> + /**
> + * @sgt: sg-table pointing to pages backing the GEM object.
> + *
> + * This is gathered at job creation time, such that we don't
> have
> + * to allocate in ::run_job().
> + */
> + struct sg_table *sgt;
> +
> + /**
> + * @prev_vma: Pre-allocated VMA object to deal with a remap
> situation.
> + *
> + * If the map request covers a region that's inside another
> VMA, the
> + * previous VMA will be split, requiring instantiation of a
> maximum of
> + * two new VMA objects.
> + */
> + struct panthor_vma *prev_vma;
> +
> + /**
> + * @new_vma: The new VMA object that will be inserted to the VA
> tree.
> + */
> + struct panthor_vma *new_vma;
> +
> + /**
> + * @next_vma: Pre-allocated VMA object to deal with a remap
> situation.
> + *
> + * See @prev_vma.
> + */
> + struct panthor_vma *next_vma;
> + } map;
> +};
> +
> +/**
> + * struct panthor_vm - VM object
> + *
> + * A VM is an object representing a GPU (or MCU) virtual address space.
> + * It embeds the MMU page table for this address space, a tree containing
> + * all the virtual mappings of GEM objects, and other things needed to manage
> + * the VM.
> + *
> + * Except for the MCU VM, which is managed by the kernel, all other VMs are
> + * created by userspace and mostly managed by userspace, using the
> + * %DRM_IOCTL_PANTHOR_VM_BIND ioctl.
> + *
> + * A portion of the virtual address space is reserved for kernel objects,
> + * like heap chunks, and userspace gets to decide how much of the virtual
> + * address space is left to the kernel (half of the virtual address space
> + * by default).
> + */
> +struct panthor_vm {
> + /**
> + * @base: Inherit from drm_gpuvm.
> + *
> + * We delegate all the VA management to the common drm_gpuvm framework
> + * and only implement hooks to update the MMU page table.
> + */
> + struct drm_gpuvm base;
> +
> + /**
> + * @sched: Scheduler used for asynchronous VM_BIND request.
> + *
> + * We use a 1:1 scheduler here.
> + */
> + struct drm_gpu_scheduler sched;
> +
> + /**
> + * @entity: Scheduling entity representing the VM_BIND queue.
> + *
> + * There's currently one bind queue per VM. It doesn't make sense to
> + * allow more given the VM operations are serialized anyway.
> + */
> + struct drm_sched_entity entity;
> +
> + /** @ptdev: Device. */
> + struct panthor_device *ptdev;
> +
> + /** @memattr: Value to program to the AS_MEMATTR register. */
> + u64 memattr;
> +
> + /** @pgtbl_ops: Page table operations. */
> + struct io_pgtable_ops *pgtbl_ops;
> +
> + /** @root_page_table: Stores the root page table pointer. */
> + void *root_page_table;
> +
> + /**
> + * @op_lock: Lock used to serialize operations on a VM.
> + *
> + * The serialization of jobs queued to the VM_BIND queue is already
> + * taken care of by drm_sched, but we need to serialize synchronous
> + * and asynchronous VM_BIND request. This is what this lock is for.
> + */
> + struct mutex op_lock;
> +
> + /**
> + * @op_ctx: The context attached to the currently executing VM
> operation.
> + *
> + * NULL when no operation is in progress.
> + */
> + struct panthor_vm_op_ctx *op_ctx;
> +
> + /**
> + * @mm: Memory management object representing the auto-VA/kernel-VA.
> + *
> + * Used to auto-allocate VA space for kernel-managed objects (tiler
> + * heaps, ...).
> + *
> + * For the MCU VM, this is managing the VA range that's used to map
> + * all shared interfaces.
> + *
> + * For user VMs, the range is specified by userspace, and must not
> + * exceed half of the VA space addressable.
> + */
> + struct drm_mm mm;
> +
> + /** @mm_lock: Lock protecting the @mm field. */
> + struct mutex mm_lock;
> +
> + /** @kernel_auto_va: Automatic VA-range for kernel BOs. */
> + struct {
> + /** @start: Start of the automatic VA-range for kernel BOs. */
> + u64 start;
> +
> + /** @size: Size of the automatic VA-range for kernel BOs. */
> + u64 end;
> + } kernel_auto_va;
> +
> + /** @as: Address space related fields. */
> + struct {
> + /**
> + * @id: ID of the address space this VM is bound to.
> + *
> + * A value of -1 means the VM is inactive/not bound.
> + */
> + int id;
> +
> + /**
> + * @lru_node: Used to instead the VM in the
> panthor_mmu::as::lru_list.
> + *
> + * Active VMs should not be inserted in the LRU list.
> + */
> + struct list_head lru_node;
> + } as;
> +
> + /**
> + * @heaps: Tiler heap related fields.
> + */
> + struct {
> + /**
> + * @pool: The heap pool attached to this VM.
> + *
> + * Will stay NULL until someone creates a heap context on this
> VM.
> + */
> + struct panthor_heap_pool *pool;
> +
> + /** @lock: Lock used to protect access to @pool. */
> + struct mutex lock;
> + } heaps;
> +
> + /** @node: Used to insert the VM in the panthor_mmu::vm::list. */
> + struct list_head node;
> +
> + /** @for_mcu: True if this is the MCU VM. */
> + bool for_mcu;
> +
> + /**
> + * @destroyed: True if the VM was destroyed.
> + *
> + * No further bind requests should be queued to a destroyed VM.
> + */
> + bool destroyed;
> +
> + /**
> + * @unusable: True if the VM has turned unusable because something
> + * bad happened during an asynchronous request.
> + *
> + * We don't try to recover from such failures, because this implies
> + * informing userspace about the specific operation that failed, and
> + * hoping the userspace driver can replay things from there. This all
> + * sounds very complicated for little gain.
> + *
> + * Instead, we should just flag the VM as unusable, and fail any
> + * further request targeting this VM.
> + *
> + * We also provide a way to query a VM state, so userspace can destroy
> + * it and create a new one.
> + *
> + * As an analogy, this would be mapped to a VK_ERROR_DEVICE_LOST
> + * situation, where the logical device needs to be re-created.
> + */
> + bool unusable;
> +
> + /**
> + * @unhandled_fault: Unhandled fault happened.
> + *
> + * This should be reported to the scheduler, and the queue/group be
> + * flagged as faulty as a result.
> + */
> + bool unhandled_fault;
> +};
> +
> +/**
> + * struct panthor_vm_bind_job - VM bind job
> + */
> +struct panthor_vm_bind_job {
> + /** @base: Inherit from drm_sched_job. */
> + struct drm_sched_job base;
> +
> + /** @refcount: Reference count. */
> + struct kref refcount;
> +
> + /** @cleanup_op_ctx_work: Work used to cleanup the VM operation
> context. */
> + struct work_struct cleanup_op_ctx_work;
> +
> + /** @vm: VM targeted by the VM operation. */
> + struct panthor_vm *vm;
> +
> + /** @ctx: Operation context. */
> + struct panthor_vm_op_ctx ctx;
> +};
> +
> +/**
> + * @pt_cache: Cache used to allocate MMU page tables.
> + *
> + * The pre-allocation pattern forces us to over-allocate to plan for
> + * the worst case scenario, and return the pages we didn't use.
> + *
> + * Having a kmem_cache allows us to speed allocations.
> + */
> +static struct kmem_cache *pt_cache;
> +
> +/**
> + * alloc_pt() - Custom page table allocator
> + * @cookie: Cookie passed at page table allocation time.
> + * @size: Size of the page table. This size should be fixed,
> + * and determined at creation time based on the granule size.
> + * @gfp: GFP flags.
> + *
> + * We want a custom allocator so we can use a cache for page table
> + * allocations and amortize the cost of the over-reservation that's
> + * done to allow asynchronous VM operations.
> + *
> + * Return: non-NULL on success, NULL if the allocation failed for any
> + * reason.
> + */
> +static void *alloc_pt(void *cookie, size_t size, gfp_t gfp)
> +{
> + struct panthor_vm *vm = cookie;
> + void *page;
> +
> + /* Allocation of the root page table happening during init. */
> + if (unlikely(!vm->pgtbl_ops)) {
I'm not that keen on using pgtbl_ops as the proxy for this. Can we use
root_page_table instead?
At the moment if the IOMMU code ever did multiple allocations during
alloc_io_pgtable_ops() then we'd overwrite root_page_table and screw up
on the free path.
If we use root_page_table == NULL as the check then things will
'cleanly' fail by falling through to the non-root case in that case.
Of course this really looks like we should have had a different
allocator for the root table but I'm not (re)opening that can of worms! ;)
And of course it doesn't make any sense for the IOMMU code to do
multiple allocations so this is all rather academic - but maybe one day
there will be a different page table structure (16K pages maybe?).
> + struct page *p;
> +
> + drm_WARN_ON(&vm->ptdev->base, vm->op_ctx);
> + p = alloc_pages_node(dev_to_node(vm->ptdev->base.dev),
> + gfp | __GFP_ZERO, get_order(size));
> + page = p ? page_address(p) : NULL;
> + vm->root_page_table = page;
> + return page;
> + }
> +
> + /* We're not supposed to have anything bigger than 4k here, because we
> picked a
> + * 4k granule size at init time.
> + */
> + if (drm_WARN_ON(&vm->ptdev->base, size != SZ_4K))
> + return NULL;
> +
> + /* We must have some op_ctx attached to the VM and it must have at
> least one
> + * free page.
> + */
> + if (drm_WARN_ON(&vm->ptdev->base, !vm->op_ctx) ||
> + drm_WARN_ON(&vm->ptdev->base,
> + vm->op_ctx->rsvd_page_tables.ptr >=
> vm->op_ctx->rsvd_page_tables.count))
> + return NULL;
> +
> + page =
> vm->op_ctx->rsvd_page_tables.pages[vm->op_ctx->rsvd_page_tables.ptr++];
> + memset(page, 0, SZ_4K);
> +
> + /* Page table entries don't use virtual addresses, which trips out
> + * kmemleak. kmemleak_alloc_phys() might work, but physical addresses
> + * are mixed with other fields, and I fear kmemleak won't detect that
> + * either.
> + *
> + * Let's just ignore memory passed to the page-table driver for now.
> + */
> + kmemleak_ignore(page);
> + return page;
> +}
> +
> +/**
> + * @free_pt() - Custom page table free function
> + * @cookie: Cookie passed at page table allocation time.
> + * @data: Page table to free.
> + * @size: Size of the page table. This size should be fixed,
> + * and determined at creation time based on the granule size.
> + */
> +static void free_pt(void *cookie, void *data, size_t size)
> +{
> + struct panthor_vm *vm = cookie;
> +
> + if (unlikely(vm->root_page_table == data)) {
> + free_pages((unsigned long)data, get_order(size));
Maybe add "vm->root_page_table = NULL;"?
> + return;
> + }
> +
> + if (drm_WARN_ON(&vm->ptdev->base, size != SZ_4K))
> + return;
> +
> + /* Return the page to the pt_cache. */
> + kmem_cache_free(pt_cache, data);
> +}
> +
> +static int wait_ready(struct panthor_device *ptdev, u32 as_nr)
> +{
> + int ret;
> + u32 val;
> +
> + /* Wait for the MMU status to indicate there is no active command, in
> + * case one is pending.
> + */
> + ret = readl_relaxed_poll_timeout_atomic(ptdev->iomem + AS_STATUS(as_nr),
> + val, !(val &
> AS_STATUS_AS_ACTIVE),
> + 10, 100000);
> +
> + if (ret) {
> + panthor_device_schedule_reset(ptdev);
> + drm_err(&ptdev->base, "AS_ACTIVE bit stuck\n");
> + }
> +
> + return ret;
> +}
> +
> +static int write_cmd(struct panthor_device *ptdev, u32 as_nr, u32 cmd)
> +{
> + int status;
> +
> + /* write AS_COMMAND when MMU is ready to accept another command */
> + status = wait_ready(ptdev, as_nr);
> + if (!status)
> + gpu_write(ptdev, AS_COMMAND(as_nr), cmd);
> +
> + return status;
> +}
> +
> +static void lock_region(struct panthor_device *ptdev, u32 as_nr,
> + u64 region_start, u64 size)
> +{
> + u8 region_width;
> + u64 region;
> + u64 region_end = region_start + size;
> +
> + if (!size)
> + return;
> +
> + /*
> + * The locked region is a naturally aligned power of 2 block encoded as
> + * log2 minus(1).
> + * Calculate the desired start/end and look for the highest bit which
> + * differs. The smallest naturally aligned block must include this bit
> + * change, the desired region starts with this bit (and subsequent bits)
> + * zeroed and ends with the bit (and subsequent bits) set to one.
> + */
> + region_width = max(fls64(region_start ^ (region_end - 1)),
> + const_ilog2(AS_LOCK_REGION_MIN_SIZE)) - 1;
> +
> + /*
> + * Mask off the low bits of region_start (which would be ignored by
> + * the hardware anyway)
> + */
> + region_start &= GENMASK_ULL(63, region_width);
> +
> + region = region_width | region_start;
> +
> + /* Lock the region that needs to be updated */
> + gpu_write(ptdev, AS_LOCKADDR_LO(as_nr), lower_32_bits(region));
> + gpu_write(ptdev, AS_LOCKADDR_HI(as_nr), upper_32_bits(region));
> + write_cmd(ptdev, as_nr, AS_COMMAND_LOCK);
> +}
> +
> +static int mmu_hw_do_operation_locked(struct panthor_device *ptdev, int
> as_nr,
> + u64 iova, u64 size, u32 op)
> +{
> + lockdep_assert_held(&ptdev->mmu->as.slots_lock);
> +
> + if (as_nr < 0)
> + return 0;
> +
> + if (op != AS_COMMAND_UNLOCK)
> + lock_region(ptdev, as_nr, iova, size);
> +
> + /* Run the MMU operation */
> + write_cmd(ptdev, as_nr, op);
> +
> + /* Wait for the flush to complete */
> + return wait_ready(ptdev, as_nr);
> +}
> +
> +static int mmu_hw_do_operation(struct panthor_vm *vm,
> + u64 iova, u64 size, u32 op)
> +{
> + struct panthor_device *ptdev = vm->ptdev;
> + int ret;
> +
> + mutex_lock(&ptdev->mmu->as.slots_lock);
> + ret = mmu_hw_do_operation_locked(ptdev, vm->as.id, iova, size, op);
> + mutex_unlock(&ptdev->mmu->as.slots_lock);
> +
> + return ret;
> +}
> +
> +static int panthor_mmu_as_enable(struct panthor_device *ptdev, u32 as_nr,
> + u64 transtab, u64 transcfg, u64 memattr)
> +{
> + int ret;
> +
> + ret = mmu_hw_do_operation_locked(ptdev, as_nr, 0, ~0ULL,
> AS_COMMAND_FLUSH_MEM);
> + if (ret)
> + return ret;
> +
> + gpu_write(ptdev, AS_TRANSTAB_LO(as_nr), lower_32_bits(transtab));
> + gpu_write(ptdev, AS_TRANSTAB_HI(as_nr), upper_32_bits(transtab));
> +
> + gpu_write(ptdev, AS_MEMATTR_LO(as_nr), lower_32_bits(memattr));
> + gpu_write(ptdev, AS_MEMATTR_HI(as_nr), upper_32_bits(memattr));
> +
> + gpu_write(ptdev, AS_TRANSCFG_LO(as_nr), lower_32_bits(transcfg));
> + gpu_write(ptdev, AS_TRANSCFG_HI(as_nr), upper_32_bits(transcfg));
> +
> + return write_cmd(ptdev, as_nr, AS_COMMAND_UPDATE);
> +}
> +
> +static int panthor_mmu_as_disable(struct panthor_device *ptdev, u32 as_nr)
> +{
> + int ret;
> +
> + ret = mmu_hw_do_operation_locked(ptdev, as_nr, 0, ~0ULL,
> AS_COMMAND_FLUSH_MEM);
> + if (ret)
> + return ret;
> +
> + gpu_write(ptdev, AS_TRANSTAB_LO(as_nr), 0);
> + gpu_write(ptdev, AS_TRANSTAB_HI(as_nr), 0);
> +
> + gpu_write(ptdev, AS_MEMATTR_LO(as_nr), 0);
> + gpu_write(ptdev, AS_MEMATTR_HI(as_nr), 0);
> +
> + gpu_write(ptdev, AS_TRANSCFG_LO(as_nr), AS_TRANSCFG_ADRMODE_UNMAPPED);
> + gpu_write(ptdev, AS_TRANSCFG_HI(as_nr), 0);
> +
> + return write_cmd(ptdev, as_nr, AS_COMMAND_UPDATE);
> +}
> +
> +static u32 panthor_mmu_fault_mask(struct panthor_device *ptdev, u32 value)
> +{
> + /* Bits 16 to 31 mean REQ_COMPLETE. */
> + return value & GENMASK(15, 0);
> +}
> +
> +static u32 panthor_mmu_as_fault_mask(struct panthor_device *ptdev, u32 as)
> +{
> + return BIT(as);
> +}
> +
> +/**
> + * panthor_vm_has_unhandled_faults() - Check if a VM has unhandled faults
> + * @vm: VM to check.
> + *
> + * Return: true if the VM has unhandled faults, false otherwise.
> + */
> +bool panthor_vm_has_unhandled_faults(struct panthor_vm *vm)
> +{
> + return vm->unhandled_fault;
> +}
> +
> +/**
> + * panthor_vm_active() - Flag a VM as active
> + * @VM: VM to flag as active.
> + *
> + * Assigns an address space to a VM so it can be used by the GPU/MCU.
> + *
> + * Return: 0 on success, a negative error code otherwise.
> + */
> +int panthor_vm_active(struct panthor_vm *vm)
> +{
> + struct panthor_device *ptdev = vm->ptdev;
> + struct io_pgtable_cfg *cfg =
> &io_pgtable_ops_to_pgtable(vm->pgtbl_ops)->cfg;
> + int ret = 0, as, cookie;
> + u64 transtab, transcfg;
> +
> + if (!drm_dev_enter(&ptdev->base, &cookie))
> + return -ENODEV;
> +
> + mutex_lock(&ptdev->mmu->as.slots_lock);
> +
> + as = vm->as.id;
> + if (as >= 0) {
> + /* Unhandled pagefault on this AS, the MMU was disabled. We
> need to
> + * re-enable the MMU after clearing+unmasking the AS interrupts.
> + */
> + if (ptdev->mmu->as.faulty_mask &
> panthor_mmu_as_fault_mask(ptdev, as))
> + goto out_enable_as;
> +
> + goto out_unlock;
> + }
> +
> + /* Check for a free AS */
> + if (vm->for_mcu) {
> + drm_WARN_ON(&ptdev->base, ptdev->mmu->as.alloc_mask & BIT(0));
> + as = 0;
> + } else {
> + as = ffz(ptdev->mmu->as.alloc_mask | BIT(0));
> + }
> +
> + if (!(BIT(as) & ptdev->gpu_info.as_present)) {
> + struct panthor_vm *lru_vm;
> +
> + lru_vm = list_first_entry_or_null(&ptdev->mmu->as.lru_list,
> + struct panthor_vm,
> + as.lru_node);
> + if (drm_WARN_ON(&ptdev->base, !lru_vm)) {
> + ret = -EBUSY;
> + goto out_unlock;
> + }
> +
> + list_del_init(&lru_vm->as.lru_node);
> + as = lru_vm->as.id;
> +
> + lru_vm->as.id = -1;
> + } else {
> + set_bit(as, &ptdev->mmu->as.alloc_mask);
> + }
> +
> + /* Assign the free or reclaimed AS to the FD */
> + vm->as.id = as;
> + ptdev->mmu->as.slots[as].vm = vm;
> +
> +out_enable_as:
> + transtab = cfg->arm_lpae_s1_cfg.ttbr;
> + transcfg = AS_TRANSCFG_PTW_MEMATTR_WB |
> + AS_TRANSCFG_PTW_RA |
> + AS_TRANSCFG_ADRMODE_AARCH64_4K;
> + if (ptdev->coherent)
> + transcfg |= AS_TRANSCFG_PTW_SH_OS;
> +
> + /* If the VM is re-activated, we clear the fault. */
> + vm->unhandled_fault = false;
> +
> + /* Unhandled pagefault on this AS, clear the fault and re-enable
> interrupts
> + * before enabling the AS.
> + */
> + if (ptdev->mmu->as.faulty_mask & panthor_mmu_as_fault_mask(ptdev, as)) {
> + gpu_write(ptdev, MMU_INT_CLEAR,
> panthor_mmu_as_fault_mask(ptdev, as));
> + ptdev->mmu->as.faulty_mask &= ~panthor_mmu_as_fault_mask(ptdev,
> as);
> + gpu_write(ptdev, MMU_INT_MASK, ~ptdev->mmu->as.faulty_mask);
> + }
> +
> + ret = panthor_mmu_as_enable(vm->ptdev, vm->as.id, transtab, transcfg,
> vm->memattr);
> +
> +out_unlock:
> + mutex_unlock(&ptdev->mmu->as.slots_lock);
> + drm_dev_exit(cookie);
> + return ret;
> +}
> +
> +/**
> + * panthor_vm_idle() - Flag a VM idle
> + * @VM: VM to flag as idle.
> + *
> + * When we know the GPU is done with the VM (no more jobs to process),
> + * we can relinquish the AS slot attached to this VM, if any.
> + *
> + * We don't release the slot immediately, but instead place the VM in
> + * the LRU list, so it can be evicted if another VM needs an AS slot.
> + * This way, VMs keep attached to the AS they were given until we run
> + * out of free slot, limiting the number of MMU operations (TLB flush
> + * and other AS updates).
> + */
> +void panthor_vm_idle(struct panthor_vm *vm)
> +{
> + struct panthor_device *ptdev = vm->ptdev;
> +
> + mutex_lock(&ptdev->mmu->as.slots_lock);
> + if (vm->as.id >= 0 && list_empty(&vm->as.lru_node))
> + list_add_tail(&vm->as.lru_node, &ptdev->mmu->as.lru_list);
> + mutex_unlock(&ptdev->mmu->as.slots_lock);
> +}
> +
> +static void panthor_vm_stop(struct panthor_vm *vm)
> +{
> + drm_sched_stop(&vm->sched, NULL);
> +}
> +
> +static void panthor_vm_start(struct panthor_vm *vm)
> +{
> + drm_sched_start(&vm->sched, true);
> +}
> +
> +/**
> + * panthor_vm_as() - Get the AS slot attached to a VM
> + * @vm: VM to get the AS slot of.
> + *
> + * Return: -1 if the VM is not assigned an AS slot yet, >= 0 otherwise.
> + */
> +int panthor_vm_as(struct panthor_vm *vm)
> +{
> + return vm->as.id;
> +}
> +
> +static size_t get_pgsize(u64 addr, size_t size, size_t *count)
> +{
> + /*
> + * io-pgtable only operates on multiple pages within a single table
> + * entry, so we need to split at boundaries of the table size, i.e.
> + * the next block size up. The distance from address A to the next
> + * boundary of block size B is logically B - A % B, but in unsigned
> + * two's complement where B is a power of two we get the equivalence
> + * B - A % B == (B - A) % B == (n * B - A) % B, and choose n = 0 :)
> + */
> + size_t blk_offset = -addr % SZ_2M;
> +
> + if (blk_offset || size < SZ_2M) {
> + *count = min_not_zero(blk_offset, size) / SZ_4K;
> + return SZ_4K;
> + }
> + blk_offset = -addr % SZ_1G ?: SZ_1G;
> + *count = min(blk_offset, size) / SZ_2M;
> + return SZ_2M;
> +}
> +
> +static int panthor_vm_flush_range(struct panthor_vm *vm, u64 iova, u64 size)
> +{
> + struct panthor_device *ptdev = vm->ptdev;
> + int ret = 0, cookie;
> +
> + if (vm->as.id < 0)
> + return 0;
> +
> + /* If the device is unplugged, we just silently skip the flush. */
> + if (!drm_dev_enter(&ptdev->base, &cookie))
> + return 0;
> +
> + /* Flush the PTs only if we're already awake */
> + if (pm_runtime_active(ptdev->base.dev))
> + ret = mmu_hw_do_operation(vm, iova, size, AS_COMMAND_FLUSH_PT);
> +
> + drm_dev_exit(cookie);
> + return ret;
> +}
> +
> +static int panthor_vm_unmap_pages(struct panthor_vm *vm, u64 iova, u64 size)
> +{
> + struct panthor_device *ptdev = vm->ptdev;
> + struct io_pgtable_ops *ops = vm->pgtbl_ops;
> + u64 offset = 0;
> +
> + drm_dbg(&ptdev->base, "unmap: as=%d, iova=%llx, len=%llx", vm->as.id,
> iova, size);
> +
> + while (offset < size) {
> + size_t unmapped_sz = 0, pgcount;
> + size_t pgsize = get_pgsize(iova + offset, size - offset,
> &pgcount);
> +
> + unmapped_sz = ops->unmap_pages(ops, iova + offset, pgsize,
> pgcount, NULL);
> +
> + if (drm_WARN_ON(&ptdev->base, unmapped_sz != pgsize * pgcount))
> {
> + drm_err(&ptdev->base, "failed to unmap range %llx-%llx
> (requested range %llx-%llx)\n",
> + iova + offset + unmapped_sz,
> + iova + offset + pgsize * pgcount,
> + iova, iova + size);
> + panthor_vm_flush_range(vm, iova, offset + unmapped_sz);
> + return -EINVAL;
> + }
> + offset += unmapped_sz;
> + }
> +
> + return panthor_vm_flush_range(vm, iova, size);
> +}
> +
> +static int
> +panthor_vm_map_pages(struct panthor_vm *vm, u64 iova, int prot,
> + struct sg_table *sgt, u64 offset, u64 size)
> +{
> + struct panthor_device *ptdev = vm->ptdev;
> + unsigned int count;
> + struct scatterlist *sgl;
> + struct io_pgtable_ops *ops = vm->pgtbl_ops;
> + u64 start_iova = iova;
> + int ret;
> +
> + if (!size)
> + return 0;
> +
> + for_each_sgtable_dma_sg(sgt, sgl, count) {
> + dma_addr_t paddr = sg_dma_address(sgl);
> + size_t len = sg_dma_len(sgl);
> +
> + if (len <= offset) {
> + offset -= len;
> + continue;
> + }
> +
> + paddr -= offset;
> + len -= offset;
> +
> + if (size >= 0) {
> + len = min_t(size_t, len, size);
> + size -= len;
> + }
> +
> + drm_dbg(&ptdev->base, "map: as=%d, iova=%llx, paddr=%pad,
> len=%zx",
> + vm->as.id, iova, &paddr, len);
> +
> + while (len) {
> + size_t pgcount, mapped = 0;
> + size_t pgsize = get_pgsize(iova | paddr, len, &pgcount);
> +
> + ret = ops->map_pages(ops, iova, paddr, pgsize, pgcount,
> prot,
> + GFP_KERNEL, &mapped);
> + iova += mapped;
> + paddr += mapped;
> + len -= mapped;
> +
> + if (drm_WARN_ON(&ptdev->base, !ret && !mapped))
> + ret = -ENOMEM;
> +
> + if (ret) {
> + /* If something failed, unmap what we've
> already mapped before
> + * returning. The unmap call is not supposed to
> fail.
> + */
> + drm_WARN_ON(&ptdev->base,
> + panthor_vm_unmap_pages(vm,
> start_iova,
> + iova -
> start_iova));
> + return ret;
> + }
> + }
> +
> + if (!size)
> + break;
> + }
> +
> + return panthor_vm_flush_range(vm, start_iova, iova - start_iova);
> +}
> +
> +static int flags_to_prot(u32 flags)
> +{
> + int prot = 0;
> +
> + if (flags & DRM_PANTHOR_VM_BIND_OP_MAP_NOEXEC)
> + prot |= IOMMU_NOEXEC;
> +
> + if (!(flags & DRM_PANTHOR_VM_BIND_OP_MAP_UNCACHED))
> + prot |= IOMMU_CACHE;
> +
> + if (flags & DRM_PANTHOR_VM_BIND_OP_MAP_READONLY)
> + prot |= IOMMU_READ;
> + else
> + prot |= IOMMU_READ | IOMMU_WRITE;
> +
> + return prot;
> +}
> +
> +/**
> + * panthor_vm_alloc_va() - Allocate a region in the auto-va space
> + * @VM: VM to allocate a region on.
> + * @size: Size of the region.
kerneldoc needs updating for the new arguments.
> + *
> + * Some GPU objects, like heap chunks, are fully managed by the kernel and
> + * need to be mapped to the userspace VM, in the region reserved for kernel
> + * objects.
> + *
> + * This function takes care of allocating a region in this reserved space.
> + *
> + * Return: A valid pointer on success, and ERR_PTR() otherwise.
Returns an error code not a pointer.
> + */
> +int
> +panthor_vm_alloc_va(struct panthor_vm *vm, u64 va, u64 size,
> + struct drm_mm_node *va_node)
> +{
> + int ret;
> +
> + if (!size || (size & ~PAGE_MASK))
> + return -EINVAL;
> +
> + if (va != PANTHOR_VM_KERNEL_AUTO_VA && (va & ~PAGE_MASK))
> + return -EINVAL;
> +
> + mutex_lock(&vm->mm_lock);
> + if (va != PANTHOR_VM_KERNEL_AUTO_VA) {
> + memset(va_node, 0, sizeof(*va_node));
This memset() seems redundant. I certainly can't see why it's only
required on this path.
> + va_node->start = va;
> + va_node->size = size;
> + ret = drm_mm_reserve_node(&vm->mm, va_node);
> + } else {
> + ret = drm_mm_insert_node_in_range(&vm->mm, va_node, size,
> + size >= SZ_2M ? SZ_2M : SZ_4K,
> + 0, vm->kernel_auto_va.start,
> + vm->kernel_auto_va.end,
> + DRM_MM_INSERT_BEST);
> + }
> + mutex_unlock(&vm->mm_lock);
> +
> + return ret;
> +}
> +
> +/**
> + * panthor_vm_free_va() - Free a region allocated with panthor_vm_alloc_va()
> + * @VM: VM to free the region on.
> + * @mm_node: Memory node representing the region to free.
> + */
> +void panthor_vm_free_va(struct panthor_vm *vm, struct drm_mm_node *va_node)
> +{
> + mutex_lock(&vm->mm_lock);
> + drm_mm_remove_node(va_node);
> + mutex_unlock(&vm->mm_lock);
> +}
> +
> +static void panthor_vm_bo_put(struct drm_gpuvm_bo *vm_bo)
> +{
> + struct panthor_gem_object *bo = to_panthor_bo(vm_bo->obj);
> + bool unpin;
> +
> + /* We must retain the GEM before calling drm_gpuvm_bo_put(),
> + * otherwise the mutex might be destroyed while we hold it.
> + */
> + drm_gem_object_get(&bo->base.base);
> + mutex_lock(&bo->gpuva_list_lock);
> + unpin = drm_gpuvm_bo_put(vm_bo);
> + mutex_unlock(&bo->gpuva_list_lock);
> +
> + /* If the vm_bo object was destroyed, release the pin reference that
> + * was hold by this object.
> + */
> + if (unpin && !bo->base.base.import_attach)
> + drm_gem_shmem_unpin(&bo->base);
> +
> + drm_gem_object_put(&bo->base.base);
> +}
> +
> +static void panthor_vm_cleanup_op_ctx(struct panthor_vm_op_ctx *op_ctx,
> + struct panthor_vm *vm)
> +{
> + struct panthor_vma *vma, *tmp_vma;
> +
> + u32 remaining_pt_count = op_ctx->rsvd_page_tables.count -
> + op_ctx->rsvd_page_tables.ptr;
> +
> + if (remaining_pt_count) {
> + kmem_cache_free_bulk(pt_cache, remaining_pt_count,
> + op_ctx->rsvd_page_tables.pages +
> + op_ctx->rsvd_page_tables.ptr);
> + }
> +
> + kfree(op_ctx->rsvd_page_tables.pages);
> + memset(&op_ctx->rsvd_page_tables, 0, sizeof(op_ctx->rsvd_page_tables));
> +
> + if (op_ctx->map.vm_bo)
> + panthor_vm_bo_put(op_ctx->map.vm_bo);
> +
> + kfree(op_ctx->map.new_vma);
> + kfree(op_ctx->map.next_vma);
> + kfree(op_ctx->map.prev_vma);
> + memset(&op_ctx->map, 0, sizeof(op_ctx->map));
> +
> + list_for_each_entry_safe(vma, tmp_vma, &op_ctx->returned_vmas, node) {
> + list_del(&vma->node);
> + panthor_vm_bo_put(vma->base.vm_bo);
> + kfree(vma);
> + }
> +}
> +
> +#define PANTHOR_VM_BIND_OP_MAP_FLAGS \
> + (DRM_PANTHOR_VM_BIND_OP_MAP_READONLY | \
> + DRM_PANTHOR_VM_BIND_OP_MAP_NOEXEC | \
> + DRM_PANTHOR_VM_BIND_OP_MAP_UNCACHED | \
> + DRM_PANTHOR_VM_BIND_OP_TYPE_MASK)
> +
> +static int panthor_vm_prepare_map_op_ctx(struct panthor_vm_op_ctx *op_ctx,
> + struct panthor_vm *vm,
> + struct panthor_gem_object *bo,
> + u64 offset,
> + u64 size, u64 va,
> + u32 flags)
> +{
> + struct drm_gpuvm_bo *preallocated_vm_bo;
> + struct sg_table *sgt = NULL;
> + u64 pt_count;
> + int ret;
> +
> + if (!bo)
> + return -EINVAL;
> +
> + if ((flags & ~PANTHOR_VM_BIND_OP_MAP_FLAGS) ||
> + (flags & DRM_PANTHOR_VM_BIND_OP_TYPE_MASK) !=
> DRM_PANTHOR_VM_BIND_OP_TYPE_MAP)
> + return -EINVAL;
> +
> + /* Make sure the VA and size are aligned and in-bounds. */
> + if (size > bo->base.base.size || offset > bo->base.base.size - size)
> + return -EINVAL;
> +
> + /* If the BO has an exclusive VM attached, it can't be mapped to other
> VMs. */
> + if (bo->exclusive_vm_root_gem &&
> + bo->exclusive_vm_root_gem != panthor_vm_root_gem(vm))
> + return -EINVAL;
> +
> + memset(op_ctx, 0, sizeof(*op_ctx));
> + INIT_LIST_HEAD(&op_ctx->returned_vmas);
> + op_ctx->flags = flags;
> + op_ctx->va.range = size;
> + op_ctx->va.addr = va;
> +
> + op_ctx->map.new_vma = kzalloc(sizeof(*op_ctx->map.new_vma), GFP_KERNEL);
> + op_ctx->map.next_vma = kzalloc(sizeof(*op_ctx->map.next_vma),
> GFP_KERNEL);
> + op_ctx->map.prev_vma = kzalloc(sizeof(*op_ctx->map.prev_vma),
> GFP_KERNEL);
> + if (!op_ctx->map.new_vma || !op_ctx->map.next_vma ||
> !op_ctx->map.prev_vma) {
> + ret = -ENOMEM;
> + goto err_cleanup;
> + }
> +
> + if (!bo->base.base.import_attach) {
> + /* Pre-reserve the BO pages, so the map operation doesn't have
> to
> + * allocate.
> + */
> + ret = drm_gem_shmem_pin(&bo->base);
> + if (ret)
> + goto err_cleanup;
> + }
> +
> + sgt = drm_gem_shmem_get_pages_sgt(&bo->base);
> + if (IS_ERR(sgt)) {
> + if (!bo->base.base.import_attach)
> + drm_gem_shmem_unpin(&bo->base);
> +
> + ret = PTR_ERR(sgt);
> + goto err_cleanup;
> + }
> +
> + op_ctx->map.sgt = sgt;
> +
> + preallocated_vm_bo = drm_gpuvm_bo_create(&vm->base, &bo->base.base);
> + if (!preallocated_vm_bo) {
> + if (!bo->base.base.import_attach)
> + drm_gem_shmem_unpin(&bo->base);
> +
> + ret = -ENOMEM;
> + goto err_cleanup;
> + }
> +
> + mutex_lock(&bo->gpuva_list_lock);
> + op_ctx->map.vm_bo = drm_gpuvm_bo_obtain_prealloc(preallocated_vm_bo);
> + mutex_unlock(&bo->gpuva_list_lock);
> +
> + /* If the a vm_bo for this <VM,BO> combination exists, it already
> + * retains a pin ref, and we can release the one we took earlier.
> + *
> + * If our pre-allocated vm_bo is picked, it now retains the pin ref,
> + * which will be released in panthor_vm_bo_put().
> + */
> + if (preallocated_vm_bo != op_ctx->map.vm_bo &&
> + !bo->base.base.import_attach)
> + drm_gem_shmem_unpin(&bo->base);
> +
> + op_ctx->map.bo_offset = offset;
> +
> + /* L1, L2 and L3 page tables.
> + * We could optimize L3 allocation by iterating over the sgt and merging
> + * 2M contiguous blocks, but it's simpler to over-provision and return
> + * the pages if they're not used.
> + */
> + pt_count = ((ALIGN(va + size, 1ull << 39) - ALIGN_DOWN(va, 1ull << 39))
> >> 39) +
> + ((ALIGN(va + size, 1ull << 30) - ALIGN_DOWN(va, 1ull << 30))
> >> 30) +
> + ((ALIGN(va + size, 1ull << 21) - ALIGN_DOWN(va, 1ull << 21))
> >> 21);
> +
> + op_ctx->rsvd_page_tables.pages = kcalloc(pt_count,
> +
> sizeof(*op_ctx->rsvd_page_tables.pages),
> + GFP_KERNEL);
> + if (!op_ctx->rsvd_page_tables.pages)
> + goto err_cleanup;
> +
> + ret = kmem_cache_alloc_bulk(pt_cache, GFP_KERNEL, pt_count,
> + op_ctx->rsvd_page_tables.pages);
> + op_ctx->rsvd_page_tables.count = ret;
> + if (ret != pt_count) {
> + ret = -ENOMEM;
> + goto err_cleanup;
> + }
> +
> + /* Insert BO into the extobj list last, when we know nothing can fail.
> */
> + drm_gpuvm_bo_extobj_add(op_ctx->map.vm_bo);
> +
> + return 0;
> +
> +err_cleanup:
> + panthor_vm_cleanup_op_ctx(op_ctx, vm);
> + return ret;
> +}
> +
> +static int panthor_vm_prepare_unmap_op_ctx(struct panthor_vm_op_ctx *op_ctx,
> + struct panthor_vm *vm,
> + u64 va, u64 size)
> +{
> + u32 pt_count = 0;
> + int ret;
> +
> + memset(op_ctx, 0, sizeof(*op_ctx));
> + INIT_LIST_HEAD(&op_ctx->returned_vmas);
> + op_ctx->va.range = size;
> + op_ctx->va.addr = va;
> + op_ctx->flags = DRM_PANTHOR_VM_BIND_OP_TYPE_UNMAP;
> +
> + /* Pre-allocate L3 page tables to account for the split-2M-block
> + * situation on unmap.
> + */
> + if (va != ALIGN(va, SZ_2M))
> + pt_count++;
> +
> + if (va + size != ALIGN(va + size, SZ_2M) &&
> + ALIGN(va + size, SZ_2M) != ALIGN(va, SZ_2M))
> + pt_count++;
> +
> + if (pt_count) {
> + op_ctx->rsvd_page_tables.pages = kcalloc(pt_count,
> +
> sizeof(*op_ctx->rsvd_page_tables.pages),
> + GFP_KERNEL);
> + if (!op_ctx->rsvd_page_tables.pages)
> + goto err_cleanup;
> +
> + ret = kmem_cache_alloc_bulk(pt_cache, GFP_KERNEL, pt_count,
> + op_ctx->rsvd_page_tables.pages);
> + if (ret != pt_count) {
> + ret = -ENOMEM;
> + goto err_cleanup;
> + }
> + op_ctx->rsvd_page_tables.count = pt_count;
> + }
> +
> + return 0;
> +
> +err_cleanup:
> + panthor_vm_cleanup_op_ctx(op_ctx, vm);
> + return ret;
> +}
> +
> +static void panthor_vm_prepare_sync_only_op_ctx(struct panthor_vm_op_ctx
> *op_ctx,
> + struct panthor_vm *vm)
> +{
> + memset(op_ctx, 0, sizeof(*op_ctx));
> + INIT_LIST_HEAD(&op_ctx->returned_vmas);
> + op_ctx->flags = DRM_PANTHOR_VM_BIND_OP_TYPE_SYNC_ONLY;
> +}
> +
> +/**
> + * panthor_vm_get_bo_for_va() - Get the GEM object mapped at a virtual
> address
> + * @vm: VM to look into.
> + * @va: Virtual address to search for.
> + * @bo_offset: Offset of the GEM object mapped at this virtual address.
> + * Only valid on success.
> + *
> + * The object returned by this function might no longer be mapped when the
> + * function returns. It's the caller responsibility to ensure there's no
> + * concurrent map/unmap operations making the returned value invalid, or
> + * make sure it doesn't matter if the object is no longer mapped.
> + *
> + * Return: A valid pointer on success, an ERR_PTR() otherwise.
> + */
> +struct panthor_gem_object *
> +panthor_vm_get_bo_for_va(struct panthor_vm *vm, u64 va, u64 *bo_offset)
> +{
> + struct panthor_gem_object *bo = ERR_PTR(-ENOENT);
> + struct drm_gpuva *gpuva;
> + struct panthor_vma *vma;
> +
> + /* Take the VM lock to prevent concurrent map/unmap operations. */
> + mutex_lock(&vm->op_lock);
> + gpuva = drm_gpuva_find_first(&vm->base, va, 1);
> + vma = gpuva ? container_of(gpuva, struct panthor_vma, base) : NULL;
> + if (vma && vma->base.gem.obj) {
> + drm_gem_object_get(vma->base.gem.obj);
> + bo = to_panthor_bo(vma->base.gem.obj);
> + *bo_offset = vma->base.gem.offset;
> + }
> + mutex_unlock(&vm->op_lock);
> +
> + return bo;
> +}
> +
> +#define PANTHOR_VM_MIN_KERNEL_VA_SIZE SZ_256M
> +
> +static u64
> +panthor_vm_create_get_user_va_range(const struct drm_panthor_vm_create *args,
> + u64 full_va_range)
> +{
> + u64 user_va_range;
> +
> + /* Make sure we have a minimum amount of VA space for kernel objects. */
> + if (full_va_range < PANTHOR_VM_MIN_KERNEL_VA_SIZE)
> + return 0;
> +
> + if (args->user_va_range) {
> + /* Use the user provided value if != 0. */
> + user_va_range = args->user_va_range;
> + } else if (TASK_SIZE_OF(current) < full_va_range) {
> + /* If the task VM size is smaller than the GPU VA range, pick
> this
> + * as our default user VA range, so userspace can CPU/GPU map
> buffers
> + * at the same address.
> + */
> + user_va_range = TASK_SIZE_OF(current);
> + } else {
> + /* If the GPU VA range is smaller than the task VM size, we
> + * just have to live with the fact we won't be able to map
> + * all buffers at the same GPU/CPU address.
> + *
> + * If the GPU VA range is bigger than 4G (more than 32-bit of
> + * VA), we split the range in two, and assign half of it to
> + * the user and the other half to the kernel, if it's not, we
> + * keep the kernel VA space as small as possible.
> + */
> + user_va_range = full_va_range > SZ_4G ?
> + full_va_range / 2 :
> + full_va_range - PANTHOR_VM_MIN_KERNEL_VA_SIZE;
> + }
> +
> + if (full_va_range - PANTHOR_VM_MIN_KERNEL_VA_SIZE < user_va_range)
> + user_va_range = full_va_range - PANTHOR_VM_MIN_KERNEL_VA_SIZE;
> +
> + return user_va_range;
> +}
> +
> +#define PANTHOR_VM_CREATE_FLAGS 0
> +
> +static int
> +panthor_vm_create_check_args(const struct panthor_device *ptdev,
> + const struct drm_panthor_vm_create *args,
> + u64 *kernel_va_start, u64 *kernel_va_range)
> +{
> + u32 va_bits = GPU_MMU_FEATURES_VA_BITS(ptdev->gpu_info.mmu_features);
> + u64 full_va_range = 1ull << min_t(u32, va_bits, sizeof(unsigned long) *
> 8);
> + u64 user_va_range;
> +
> + if (args->flags & ~PANTHOR_VM_CREATE_FLAGS)
> + return -EINVAL;
> +
> + user_va_range = panthor_vm_create_get_user_va_range(args,
> full_va_range);
> + if (!user_va_range || (args->user_va_range && args->user_va_range >
> user_va_range))
> + return -EINVAL;
> +
> + /* Pick a kernel VA range that's a power of two, to have a clear split.
> */
> + *kernel_va_range = rounddown_pow_of_two(full_va_range - user_va_range);
> + *kernel_va_start = full_va_range - *kernel_va_range;
> + return 0;
> +}
> +
> +/*
> + * Only 32 VMs per open file. If that becomes a limiting factor, we can
> + * increase this number.
> + */
> +#define PANTHOR_MAX_VMS_PER_FILE 32
> +
> +/**
> + * panthor_vm_pool_create_vm() - Create a VM
> + * @pool: The VM to create this VM on.
> + * @kernel_va_start: Start of the region reserved for kernel objects.
> + * @kernel_va_range: Size of the region reserved for kernel objects.
> + *
> + * Return: 0 on success, a negative error code otherwise.
Actually returns the (positive) id on success.
> + */
> +int panthor_vm_pool_create_vm(struct panthor_device *ptdev,
> + struct panthor_vm_pool *pool,
> + struct drm_panthor_vm_create *args)
> +{
> + u64 kernel_va_start, kernel_va_range;
> + struct panthor_vm *vm;
> + int ret;
> + u32 id;
> +
> + ret = panthor_vm_create_check_args(ptdev, args, &kernel_va_start,
> &kernel_va_range);
> + if (ret)
> + return ret;
> +
> + vm = panthor_vm_create(ptdev, false, kernel_va_start, kernel_va_range,
> + kernel_va_start, kernel_va_range);
> + if (IS_ERR(vm))
> + return PTR_ERR(vm);
> +
> + ret = xa_alloc(&pool->xa, &id, vm,
> + XA_LIMIT(1, PANTHOR_MAX_VMS_PER_FILE), GFP_KERNEL);
> +
> + if (ret) {
> + panthor_vm_put(vm);
> + return ret;
> + }
> +
> + args->user_va_range = kernel_va_start;
> + return id;
> +}
> +
> +static void panthor_vm_destroy(struct panthor_vm *vm)
> +{
> + if (!vm)
> + return;
> +
> + vm->destroyed = true;
> +
> + mutex_lock(&vm->heaps.lock);
> + panthor_heap_pool_destroy(vm->heaps.pool);
> + vm->heaps.pool = NULL;
> + mutex_unlock(&vm->heaps.lock);
> +
> + drm_WARN_ON(&vm->ptdev->base,
> + panthor_vm_unmap_range(vm, vm->base.mm_start,
> vm->base.mm_range));
> + panthor_vm_put(vm);
> +}
> +
> +/**
> + * panthor_vm_destroy() - Destroy a VM.
> + * @pool: VM pool.
> + * @handle: VM handle.
> + *
> + * This function doesn't free the VM object or its resources, it just kills
> + * all mappings, and makes sure nothing can be mapped after that point.
> + *
> + * If there was any active jobs at the time this function is called, these
> + * jobs should experience page faults and be killed as a result.
> + *
> + * The VM resources are freed when the last reference on the VM object is
> + * dropped.
> + */
> +int panthor_vm_pool_destroy_vm(struct panthor_vm_pool *pool, u32 handle)
> +{
> + struct panthor_vm *vm;
> +
> + vm = xa_erase(&pool->xa, handle);
> +
> + panthor_vm_destroy(vm);
> +
> + return vm ? 0 : -EINVAL;
> +}
> +
> +/**
> + * panthor_vm_pool_get_vm() - Retrieve VM object bound to a VM handle
> + * @pool: VM pool to check.
> + * @handle: Handle of the VM to retrieve.
> + *
> + * Return: A valid pointer if the VM exists, NULL otherwise.
> + */
> +struct panthor_vm *
> +panthor_vm_pool_get_vm(struct panthor_vm_pool *pool, u32 handle)
> +{
> + struct panthor_vm *vm;
> +
> + vm = panthor_vm_get(xa_load(&pool->xa, handle));
> +
> + return vm;
> +}
> +
> +/**
> + * panthor_vm_pool_destroy() - Destroy a VM pool.
> + * @pfile: File.
> + *
> + * Destroy all VMs in the pool, and release the pool resources.
> + *
> + * Note that VMs can outlive the pool they were created from if other
> + * objects hold a reference to there VMs.
> + */
> +void panthor_vm_pool_destroy(struct panthor_file *pfile)
> +{
> + struct panthor_vm *vm;
> + unsigned long i;
> +
> + if (!pfile->vms)
> + return;
> +
> + xa_for_each(&pfile->vms->xa, i, vm)
> + panthor_vm_destroy(vm);
> +
> + xa_destroy(&pfile->vms->xa);
> + kfree(pfile->vms);
> +}
> +
> +/**
> + * panthor_vm_pool_create() - Create a VM pool
> + * @pfile: File.
> + *
> + * Return: 0 on success, a negative error code otherwise.
> + */
> +int panthor_vm_pool_create(struct panthor_file *pfile)
> +{
> + pfile->vms = kzalloc(sizeof(*pfile->vms), GFP_KERNEL);
> + if (!pfile->vms)
> + return -ENOMEM;
> +
> + xa_init_flags(&pfile->vms->xa, XA_FLAGS_ALLOC1);
> + return 0;
> +}
> +
> +/* dummy TLB ops, the real TLB flush happens in panthor_vm_flush_range() */
> +static void mmu_tlb_flush_all(void *cookie)
> +{
> +}
> +
> +static void mmu_tlb_flush_walk(unsigned long iova, size_t size, size_t
> granule, void *cookie)
> +{
> +}
> +
> +static const struct iommu_flush_ops mmu_tlb_ops = {
> + .tlb_flush_all = mmu_tlb_flush_all,
> + .tlb_flush_walk = mmu_tlb_flush_walk,
> +};
> +
> +static const char *access_type_name(struct panthor_device *ptdev,
> + u32 fault_status)
> +{
> + switch (fault_status & AS_FAULTSTATUS_ACCESS_TYPE_MASK) {
> + case AS_FAULTSTATUS_ACCESS_TYPE_ATOMIC:
> + return "ATOMIC";
> + case AS_FAULTSTATUS_ACCESS_TYPE_READ:
> + return "READ";
> + case AS_FAULTSTATUS_ACCESS_TYPE_WRITE:
> + return "WRITE";
> + case AS_FAULTSTATUS_ACCESS_TYPE_EX:
> + return "EXECUTE";
> + default:
> + drm_WARN_ON(&ptdev->base, 1);
> + return NULL;
> + }
> +}
> +
> +static void panthor_mmu_irq_handler(struct panthor_device *ptdev, u32 status)
> +{
> + bool has_unhandled_faults = false;
> +
> + status = panthor_mmu_fault_mask(ptdev, status);
> + while (status) {
> + u32 as = ffs(status | (status >> 16)) - 1;
> + u32 mask = panthor_mmu_as_fault_mask(ptdev, as);
> + u32 new_int_mask;
> + u64 addr;
> + u32 fault_status;
> + u32 exception_type;
> + u32 access_type;
> + u32 source_id;
> +
> + fault_status = gpu_read(ptdev, AS_FAULTSTATUS(as));
> + addr = gpu_read(ptdev, AS_FAULTADDRESS_LO(as));
> + addr |= (u64)gpu_read(ptdev, AS_FAULTADDRESS_HI(as)) << 32;
> +
> + /* decode the fault status */
> + exception_type = fault_status & 0xFF;
> + access_type = (fault_status >> 8) & 0x3;
> + source_id = (fault_status >> 16);
> +
> + mutex_lock(&ptdev->mmu->as.slots_lock);
> +
> + ptdev->mmu->as.faulty_mask |= mask;
> + new_int_mask =
> + panthor_mmu_fault_mask(ptdev,
> ~ptdev->mmu->as.faulty_mask);
> +
> + /* terminal fault, print info about the fault */
> + drm_err(&ptdev->base,
> + "Unhandled Page fault in AS%d at VA 0x%016llX\n"
> + "raw fault status: 0x%X\n"
> + "decoded fault status: %s\n"
> + "exception type 0x%X: %s\n"
> + "access type 0x%X: %s\n"
> + "source id 0x%X\n",
> + as, addr,
> + fault_status,
> + (fault_status & (1 << 10) ? "DECODER FAULT" : "SLAVE
> FAULT"),
> + exception_type, panthor_exception_name(ptdev,
> exception_type),
> + access_type, access_type_name(ptdev, fault_status),
> + source_id);
> +
> + /* Ignore MMU interrupts on this AS until it's been
> + * re-enabled.
> + */
> + ptdev->mmu->irq.mask = new_int_mask;
> + gpu_write(ptdev, MMU_INT_MASK, new_int_mask);
> +
> + if (ptdev->mmu->as.slots[as].vm)
> + ptdev->mmu->as.slots[as].vm->unhandled_fault = true;
> +
> + /* Disable the MMU to kill jobs on this AS. */
> + panthor_mmu_as_disable(ptdev, as);
> + mutex_unlock(&ptdev->mmu->as.slots_lock);
> +
> + status &= ~mask;
> + has_unhandled_faults = true;
> + }
> +
> + if (has_unhandled_faults)
> + panthor_sched_report_mmu_fault(ptdev);
> +}
> +PANTHOR_IRQ_HANDLER(mmu, MMU, panthor_mmu_irq_handler);
> +
> +/**
> + * panthor_mmu_suspend() - Suspend the MMU logic
> + * @ptdev: Device.
> + *
> + * All we do here is de-assign the AS slots on all active VMs, so things
> + * get flushed to the main memory, and no further access to these VMs are
> + * possible.
> + *
> + * We also suspend the MMU IRQ.
> + */
> +void panthor_mmu_suspend(struct panthor_device *ptdev)
> +{
> + mutex_lock(&ptdev->mmu->as.slots_lock);
> + for (u32 i = 0; i < ARRAY_SIZE(ptdev->mmu->as.slots); i++) {
> + struct panthor_vm *vm = ptdev->mmu->as.slots[i].vm;
> +
> + if (vm) {
> + drm_WARN_ON(&ptdev->base, panthor_mmu_as_disable(ptdev,
> i));
> + vm->as.id = -1;
> + list_del_init(&vm->as.lru_node);
> + ptdev->mmu->as.slots[i].vm = NULL;
> + }
> + }
> + mutex_unlock(&ptdev->mmu->as.slots_lock);
> +
> + panthor_mmu_irq_suspend(&ptdev->mmu->irq);
> +}
> +
> +/**
> + * panthor_mmu_resume() - Resume the MMU logic
> + * @ptdev: Device.
> + *
> + * Resume the IRQ.
> + *
> + * We don't re-enable previously active VMs. We assume other parts of the
> + * driver will call panthor_vm_active() on the VMs they intend to use.
> + */
> +void panthor_mmu_resume(struct panthor_device *ptdev)
> +{
> + mutex_lock(&ptdev->mmu->as.slots_lock);
> + ptdev->mmu->as.alloc_mask = 0;
> + ptdev->mmu->as.faulty_mask = 0;
> + mutex_unlock(&ptdev->mmu->as.slots_lock);
> +
> + panthor_mmu_irq_resume(&ptdev->mmu->irq, panthor_mmu_fault_mask(ptdev,
> ~0));
> +}
> +
> +/**
> + * panthor_mmu_pre_reset() - Prepare for a reset
> + * @ptdev: Device.
> + *
> + * Suspend the IRQ, and make sure all VM_BIND queues are stopped, so we
> + * don't get asked to do a VM operation while the GPU is down.
> + *
> + * We don't cleanly shutdown the AS slots here, because the reset might
> + * come from an AS_ACTIVE_BIT stuck situation.
> + */
> +void panthor_mmu_pre_reset(struct panthor_device *ptdev)
> +{
> + struct panthor_vm *vm;
> +
> + panthor_mmu_irq_suspend(&ptdev->mmu->irq);
> +
> + mutex_lock(&ptdev->mmu->vm.lock);
> + ptdev->mmu->vm.reset_in_progress = true;
> + list_for_each_entry(vm, &ptdev->mmu->vm.list, node)
> + panthor_vm_stop(vm);
> + mutex_unlock(&ptdev->mmu->vm.lock);
> +}
> +
> +/**
> + * panthor_mmu_post_reset() - Restore things after a reset
> + * @ptdev: Device.
> + *
> + * Put the MMU logic back in action after a reset. That implies resuming the
> + * IRQ and re-enabling the VM_BIND queues.
> + */
> +void panthor_mmu_post_reset(struct panthor_device *ptdev)
> +{
> + struct panthor_vm *vm;
> +
> + mutex_lock(&ptdev->mmu->as.slots_lock);
> +
> + /* Now that the reset is effective, we can assume that none of the
> + * AS slots are setup, and clear the faulty flags too.
> + */
> + ptdev->mmu->as.alloc_mask = 0;
> + ptdev->mmu->as.faulty_mask = 0;
> +
> + for (u32 i = 0; i < ARRAY_SIZE(ptdev->mmu->as.slots); i++) {
> + struct panthor_vm *vm = ptdev->mmu->as.slots[i].vm;
> +
> + if (vm) {
> + vm->as.id = -1;
> + list_del_init(&vm->as.lru_node);
> + ptdev->mmu->as.slots[i].vm = NULL;
> + }
> + }
> +
> + mutex_unlock(&ptdev->mmu->as.slots_lock);
> +
> + panthor_mmu_irq_resume(&ptdev->mmu->irq, panthor_mmu_fault_mask(ptdev,
> ~0));
> +
> + /* Restart the VM_BIND queues. */
> + mutex_lock(&ptdev->mmu->vm.lock);
> + list_for_each_entry(vm, &ptdev->mmu->vm.list, node) {
> + panthor_vm_start(vm);
> + }
> + ptdev->mmu->vm.reset_in_progress = false;
> + mutex_unlock(&ptdev->mmu->vm.lock);
> +}
> +
> +static void panthor_vm_free(struct drm_gpuvm *gpuvm)
> +{
> + struct panthor_vm *vm = container_of(gpuvm, struct panthor_vm, base);
> + struct panthor_device *ptdev = vm->ptdev;
> +
> + mutex_lock(&vm->heaps.lock);
> + if (drm_WARN_ON(&ptdev->base, vm->heaps.pool))
> + panthor_heap_pool_destroy(vm->heaps.pool);
> + mutex_unlock(&vm->heaps.lock);
> + mutex_destroy(&vm->heaps.lock);
> +
> + mutex_lock(&ptdev->mmu->vm.lock);
> + list_del(&vm->node);
> + /* Restore the scheduler state so we can call drm_sched_entity_destroy()
> + * and drm_sched_fini(). If get there, that means we have no job left
> + * and no new jobs can be queued, so we can start the scheduler without
> + * risking interfering with the reset.
> + */
> + if (ptdev->mmu->vm.reset_in_progress)
> + panthor_vm_start(vm);
> + mutex_unlock(&ptdev->mmu->vm.lock);
> +
> + drm_sched_entity_destroy(&vm->entity);
> + drm_sched_fini(&vm->sched);
> +
> + mutex_lock(&ptdev->mmu->as.slots_lock);
> + if (vm->as.id >= 0) {
> + int cookie;
> +
> + if (drm_dev_enter(&ptdev->base, &cookie)) {
> + panthor_mmu_as_disable(ptdev, vm->as.id);
> + drm_dev_exit(cookie);
> + }
> +
> + ptdev->mmu->as.slots[vm->as.id].vm = NULL;
> + clear_bit(vm->as.id, &ptdev->mmu->as.alloc_mask);
> + list_del(&vm->as.lru_node);
> + }
> + mutex_unlock(&ptdev->mmu->as.slots_lock);
> +
> + free_io_pgtable_ops(vm->pgtbl_ops);
> +
> + drm_mm_takedown(&vm->mm);
> + kfree(vm);
> +}
> +
> +/**
> + * panthor_vm_put() - Release a reference on a VM
> + * @vm: VM to release the reference on. Can be NULL.
> + */
> +void panthor_vm_put(struct panthor_vm *vm)
> +{
> + static_assert(offsetof(struct panthor_vm, base) == 0);
Yuk! ;)
I'd prefer:
drm_gpuvm_put(vm ? &vm->base : NULL);
which my compiler turns into the same thing rather than relying on the
type punning. You can keep the static_assert if you like, but I don't
like relying on it for correct code generation. Although I'll admit I
couldn't actually get the compiler to produce incorrect code when I tried.
> + drm_gpuvm_put(&vm->base);
> +}
> +
> +/**
> + * panthor_vm_get() - Get a VM reference
> + * @vm: VM to get the reference on. Can be NULL.
> + *
> + * Return: @vm value.
> + */
> +struct panthor_vm *panthor_vm_get(struct panthor_vm *vm)
> +{
> + if (vm)
> + drm_gpuvm_get(&vm->base);
> +
> + return vm;
> +}
> +
> +/**
> + * panthor_vm_get_heap_pool() - Get the heap pool attached to a VM
> + * @vm: VM to query the heap pool on.
> + * @create: True if the heap pool should be created when it doesn't exist.
> + *
> + * Heap pools are per-VM. This function allows one to retrieve the heap pool
> + * attached to a VM.
> + *
> + * If no heap pool exists yet, and @create is true, we create one.
> + *
> + * The returned panthor_heap_pool should be released with
> panthor_heap_pool_put().
> + *
> + * Return: A valid pointer on success, an ERR_PTR() otherwise.
> + */
> +struct panthor_heap_pool *panthor_vm_get_heap_pool(struct panthor_vm *vm,
> bool create)
> +{
> + struct panthor_heap_pool *pool;
> +
> + mutex_lock(&vm->heaps.lock);
> + if (!vm->heaps.pool && create) {
> + if (vm->destroyed)
> + pool = ERR_PTR(-EINVAL);
> + else
> + pool = panthor_heap_pool_create(vm->ptdev, vm);
> +
> + if (!IS_ERR(pool))
> + vm->heaps.pool = panthor_heap_pool_get(pool);
> + } else {
> + pool = panthor_heap_pool_get(vm->heaps.pool);
> + }
> + mutex_unlock(&vm->heaps.lock);
> +
> + return pool;
> +}
> +
> +static u64 mair_to_memattr(u64 mair)
> +{
> + u64 memattr = 0;
> + u32 i;
> +
> + for (i = 0; i < 8; i++) {
> + u8 in_attr = mair >> (8 * i), out_attr;
> + u8 outer = in_attr >> 4, inner = in_attr & 0xf;
> +
> + /* For caching to be enabled, inner and outer caching policy
> + * have to be both write-back, if one of them is write-through
> + * or non-cacheable, we just choose non-cacheable. Device
> + * memory is also translated to non-cacheable.
> + */
> + if (!(outer & 3) || !(outer & 4) || !(inner & 4)) {
> + out_attr = AS_MEMATTR_AARCH64_INNER_OUTER_NC |
> + AS_MEMATTR_AARCH64_SH_MIDGARD_INNER |
> + AS_MEMATTR_AARCH64_INNER_ALLOC_EXPL(false,
> false);
> + } else {
> + /* Use SH_CPU_INNER mode so SH_IS, which is used when
> + * IOMMU_CACHE is set, actually maps to the standard
> + * definition of inner-shareable and not Mali's
> + * internal-shareable mode.
> + */
> + out_attr = AS_MEMATTR_AARCH64_INNER_OUTER_WB |
> + AS_MEMATTR_AARCH64_SH_CPU_INNER |
> + AS_MEMATTR_AARCH64_INNER_ALLOC_EXPL(inner &
> 1, inner & 2);
> + }
> +
> + memattr |= (u64)out_attr << (8 * i);
> + }
> +
> + return memattr;
> +}
> +
> +static void panthor_vma_link(struct panthor_vm *vm,
> + struct panthor_vma *vma,
> + struct drm_gpuvm_bo *vm_bo)
> +{
> + struct panthor_gem_object *bo = to_panthor_bo(vma->base.gem.obj);
> +
> + mutex_lock(&bo->gpuva_list_lock);
> + drm_gpuva_link(&vma->base, vm_bo);
> + drm_gpuvm_bo_put(vm_bo);
> + mutex_unlock(&bo->gpuva_list_lock);
> +}
> +
> +static void panthor_vma_unlink(struct panthor_vm *vm,
> + struct panthor_vma *vma)
> +{
> + struct panthor_gem_object *bo = to_panthor_bo(vma->base.gem.obj);
> + struct drm_gpuvm_bo *vm_bo = drm_gpuvm_bo_get(vma->base.vm_bo);
> +
> + mutex_lock(&bo->gpuva_list_lock);
> + drm_gpuva_unlink(&vma->base);
> + mutex_unlock(&bo->gpuva_list_lock);
> +
> + /* drm_gpuva_unlink() release the vm_bo, but we manually retained it
> + * when entering this function, so we can implement deferred VMA
> + * destruction. Re-assign it here.
> + */
> + vma->base.vm_bo = vm_bo;
> + list_add_tail(&vma->node, &vm->op_ctx->returned_vmas);
> +}
> +
> +static void panthor_vma_init(struct panthor_vma *vma, u32 flags)
> +{
> + INIT_LIST_HEAD(&vma->node);
> + vma->flags = flags;
> +}
> +
> +#define PANTHOR_VM_MAP_FLAGS \
> + (DRM_PANTHOR_VM_BIND_OP_MAP_READONLY | \
> + DRM_PANTHOR_VM_BIND_OP_MAP_NOEXEC | \
> + DRM_PANTHOR_VM_BIND_OP_MAP_UNCACHED)
> +
> +static int panthor_gpuva_sm_step_map(struct drm_gpuva_op *op, void *priv)
> +{
> + struct panthor_vm *vm = priv;
> + struct panthor_vm_op_ctx *op_ctx = vm->op_ctx;
> + struct panthor_vma *vma = op_ctx->map.new_vma;
> + int ret;
> +
> + panthor_vma_init(vma, op_ctx->flags & PANTHOR_VM_MAP_FLAGS);
> +
> + ret = panthor_vm_map_pages(vm, op->map.va.addr,
> flags_to_prot(vma->flags),
> + op_ctx->map.sgt, op->map.gem.offset,
> + op->map.va.range);
> + if (ret)
> + return ret;
> +
> + /* Ref owned by the mapping now, clear the obj field so we don't
> release the
> + * pinning/obj ref behind GPUVA's back.
> + */
> + drm_gpuva_map(&vm->base, &vma->base, &op->map);
> + panthor_vma_link(vm, op_ctx->map.new_vma, op_ctx->map.vm_bo);
> + op_ctx->map.vm_bo = NULL;
> + op_ctx->map.new_vma = NULL;
> + return 0;
> +}
> +
> +static int panthor_gpuva_sm_step_remap(struct drm_gpuva_op *op,
> + void *priv)
> +{
> + struct panthor_vma *unmap_vma = container_of(op->remap.unmap->va,
> struct panthor_vma, base);
> + struct panthor_vm *vm = priv;
> + struct panthor_vm_op_ctx *op_ctx = vm->op_ctx;
> + struct drm_gpuva *prev_va = NULL, *next_va = NULL;
> + u64 unmap_start, unmap_range;
> + int ret;
> +
> + drm_gpuva_op_remap_to_unmap_range(&op->remap, &unmap_start,
> &unmap_range);
> + ret = panthor_vm_unmap_pages(vm, unmap_start, unmap_range);
> + if (ret)
> + return ret;
> +
> + if (op->remap.prev) {
> + panthor_vma_init(op_ctx->map.prev_vma, unmap_vma->flags);
> + prev_va = &op_ctx->map.prev_vma->base;
> + }
> +
> + if (op->remap.next) {
> + panthor_vma_init(op_ctx->map.next_vma, unmap_vma->flags);
> + next_va = &op_ctx->map.next_vma->base;
> + }
> +
> + drm_gpuva_remap(prev_va, next_va, &op->remap);
> +
> + if (prev_va) {
> + panthor_vma_link(vm, op_ctx->map.prev_vma,
> op->remap.unmap->va->vm_bo);
> + op_ctx->map.prev_vma = NULL;
> + }
> +
> + if (next_va) {
> + panthor_vma_link(vm, op_ctx->map.next_vma,
> op->remap.unmap->va->vm_bo);
> + op_ctx->map.next_vma = NULL;
> + }
> +
> + panthor_vma_unlink(vm, unmap_vma);
> + return 0;
> +}
> +
> +static int panthor_gpuva_sm_step_unmap(struct drm_gpuva_op *op,
> + void *priv)
> +{
> + struct panthor_vma *unmap_vma = container_of(op->unmap.va, struct
> panthor_vma, base);
> + struct panthor_vm *vm = priv;
> + int ret;
> +
> + ret = panthor_vm_unmap_pages(vm, unmap_vma->base.va.addr,
> + unmap_vma->base.va.range);
> + if (drm_WARN_ON(&vm->ptdev->base, ret))
> + return ret;
> +
> + drm_gpuva_unmap(&op->unmap);
> + panthor_vma_unlink(vm, unmap_vma);
> + return 0;
> +}
> +
> +static const struct drm_gpuvm_ops panthor_gpuvm_ops = {
> + .vm_free = panthor_vm_free,
> + .sm_step_map = panthor_gpuva_sm_step_map,
> + .sm_step_remap = panthor_gpuva_sm_step_remap,
> + .sm_step_unmap = panthor_gpuva_sm_step_unmap,
> +};
> +
> +/**
> + * panthor_vm_resv() - Get the dma_resv object attached to a VM.
> + * @vm: VM to get the dma_resv of.
> + *
> + * Return: A dma_resv object.
> + */
> +struct dma_resv *panthor_vm_resv(struct panthor_vm *vm)
> +{
> + return drm_gpuvm_resv(&vm->base);
> +}
> +
> +struct drm_gem_object *panthor_vm_root_gem(struct panthor_vm *vm)
> +{
> + if (!vm)
> + return NULL;
> +
> + return vm->base.r_obj;
> +}
> +
> +static int
> +panthor_vm_exec_op(struct panthor_vm *vm, struct panthor_vm_op_ctx *op,
> + bool flag_vm_unusable_on_failure)
> +{
> + u32 op_type = op->flags & DRM_PANTHOR_VM_BIND_OP_TYPE_MASK;
> + int ret;
> +
> + if (op_type == DRM_PANTHOR_VM_BIND_OP_TYPE_SYNC_ONLY)
> + return 0;
> +
> + mutex_lock(&vm->op_lock);
> + vm->op_ctx = op;
> + switch (op_type) {
> + case DRM_PANTHOR_VM_BIND_OP_TYPE_MAP:
> + if (vm->unusable) {
> + ret = -EINVAL;
> + break;
> + }
> +
> + ret = drm_gpuvm_sm_map(&vm->base, vm, op->va.addr, op->va.range,
> + op->map.vm_bo->obj, op->map.bo_offset);
> + break;
> +
> + case DRM_PANTHOR_VM_BIND_OP_TYPE_UNMAP:
> + ret = drm_gpuvm_sm_unmap(&vm->base, vm, op->va.addr,
> op->va.range);
> + break;
> +
> + default:
> + ret = -EINVAL;
> + break;
> + }
> +
> + if (ret && flag_vm_unusable_on_failure)
> + vm->unusable = true;
> +
> + vm->op_ctx = NULL;
> + mutex_unlock(&vm->op_lock);
> +
> + return ret;
> +}
> +
> +static struct dma_fence *
> +panthor_vm_bind_run_job(struct drm_sched_job *sched_job)
> +{
> + struct panthor_vm_bind_job *job = container_of(sched_job, struct
> panthor_vm_bind_job, base);
> + bool cookie;
> + int ret;
> +
> + /* Not only we report an error whose result is propagated to the
> + * drm_sched finished fence, but we also flag the VM as unusable,
> because
> + * a failure in the async VM_BIND results in an inconsistent state. VM
> needs
> + * to be destroyed and recreated.
> + */
> + cookie = dma_fence_begin_signalling();
> + ret = panthor_vm_exec_op(job->vm, &job->ctx, true);
> + dma_fence_end_signalling(cookie);
> +
> + return ret ? ERR_PTR(ret) : NULL;
> +}
> +
> +static void panthor_vm_bind_job_release(struct kref *kref)
> +{
> + struct panthor_vm_bind_job *job = container_of(kref, struct
> panthor_vm_bind_job, refcount);
> +
> + if (job->base.s_fence)
> + drm_sched_job_cleanup(&job->base);
> +
> + panthor_vm_cleanup_op_ctx(&job->ctx, job->vm);
> + panthor_vm_put(job->vm);
> + kfree(job);
> +}
> +
> +/**
> + * panthor_vm_bind_job_put() - Release a VM_BIND job reference
> + * @sched_job: Job to release the reference on.
> + */
> +void panthor_vm_bind_job_put(struct drm_sched_job *sched_job)
> +{
> + struct panthor_vm_bind_job *job =
> + container_of(sched_job, struct panthor_vm_bind_job, base);
> +
> + if (sched_job)
> + kref_put(&job->refcount, panthor_vm_bind_job_release);
> +}
> +
> +static void
> +panthor_vm_bind_free_job(struct drm_sched_job *sched_job)
> +{
> + struct panthor_vm_bind_job *job =
> + container_of(sched_job, struct panthor_vm_bind_job, base);
> +
> + drm_sched_job_cleanup(sched_job);
> +
> + /* Do the heavy cleanups asynchronously, so we're out of the
> + * dma-signaling path and can acquire dma-resv locks safely.
> + */
> + queue_work(panthor_cleanup_wq, &job->cleanup_op_ctx_work);
> +}
> +
> +static enum drm_gpu_sched_stat
> +panthor_vm_bind_timedout_job(struct drm_sched_job *sched_job)
> +{
> + WARN(1, "VM_BIND ops are synchronous for now, there should be no
> timeout!");
> + return DRM_GPU_SCHED_STAT_NOMINAL;
> +}
> +
> +static const struct drm_sched_backend_ops panthor_vm_bind_ops = {
> + .run_job = panthor_vm_bind_run_job,
> + .free_job = panthor_vm_bind_free_job,
> + .timedout_job = panthor_vm_bind_timedout_job,
> +};
> +
> +/**
> + * panthor_vm_create() - Create a VM
> + * @ptdev: Device.
> + * @for_mcu: True if this is the FW MCU VM.
> + * @kernel_va_start: Start of the range reserved for kernel BO mapping.
> + * @kernel_va_size: Size of the range reserved for kernel BO mapping.
> + * @auto_kernel_va_start: Start of the auto-VA kernel range.
> + * @auto_kernel_va_size: Size of the auto-VA kernel range.
> + *
> + * Return: A valid pointer on success, an ERR_PTR() otherwise.
> + */
> +struct panthor_vm *
> +panthor_vm_create(struct panthor_device *ptdev, bool for_mcu,
> + u64 kernel_va_start, u64 kernel_va_size,
> + u64 auto_kernel_va_start, u64 auto_kernel_va_size)
> +{
> + u32 va_bits = GPU_MMU_FEATURES_VA_BITS(ptdev->gpu_info.mmu_features);
> + u32 pa_bits = GPU_MMU_FEATURES_PA_BITS(ptdev->gpu_info.mmu_features);
> + u64 full_va_range = 1ull << min_t(u32, va_bits, sizeof(unsigned long) *
> 8);
> + struct drm_gem_object *dummy_gem;
> + struct drm_gpu_scheduler *sched;
> + struct io_pgtable_cfg pgtbl_cfg;
> + u64 mair, min_va, va_range;
> + struct panthor_vm *vm;
> + int ret;
> +
> + vm = kzalloc(sizeof(*vm), GFP_KERNEL);
> + if (!vm)
> + return ERR_PTR(-ENOMEM);
> +
> + /* We allocate a dummy GEM for the VM. */
> + dummy_gem = drm_gpuvm_resv_object_alloc(&ptdev->base);
> + if (!dummy_gem) {
> + ret = -ENOMEM;
> + goto err_free_vm;
> + }
> +
> + mutex_init(&vm->heaps.lock);
> + vm->for_mcu = for_mcu;
> + vm->ptdev = ptdev;
> + mutex_init(&vm->op_lock);
> +
> + if (for_mcu) {
> + /* CSF MCU is a cortex M7, and can only address 4G */
> + min_va = 0;
> + va_range = SZ_4G;
> + } else {
> + min_va = 0;
> + va_range = full_va_range;
> + }
> +
> + mutex_init(&vm->mm_lock);
> + drm_mm_init(&vm->mm, kernel_va_start, kernel_va_size);
> + vm->kernel_auto_va.start = auto_kernel_va_start;
> + vm->kernel_auto_va.end = vm->kernel_auto_va.start + auto_kernel_va_size
> - 1;
> +
> + INIT_LIST_HEAD(&vm->node);
> + INIT_LIST_HEAD(&vm->as.lru_node);
> + vm->as.id = -1;
> +
> + pgtbl_cfg = (struct io_pgtable_cfg) {
> + .pgsize_bitmap = SZ_4K | SZ_2M,
> + .ias = va_bits,
> + .oas = pa_bits,
> + .coherent_walk = ptdev->coherent,
> + .tlb = &mmu_tlb_ops,
> + .iommu_dev = ptdev->base.dev,
> + .alloc = alloc_pt,
> + .free = free_pt,
> + };
> +
> + vm->pgtbl_ops = alloc_io_pgtable_ops(ARM_64_LPAE_S1, &pgtbl_cfg, vm);
> + if (!vm->pgtbl_ops) {
> + ret = -EINVAL;
> + goto err_mm_takedown;
> + }
> +
> + /* Bind operations are synchronous for now, no timeout needed. */
> + ret = drm_sched_init(&vm->sched, &panthor_vm_bind_ops,
> ptdev->mmu->vm.wq,
> + 1, 1, 0,
> + MAX_SCHEDULE_TIMEOUT, NULL, NULL,
> + "panthor-vm-bind", ptdev->base.dev);
> + if (ret)
> + goto err_free_io_pgtable;
> +
> + sched = &vm->sched;
> + ret = drm_sched_entity_init(&vm->entity, 0, &sched, 1, NULL);
> + if (ret)
> + goto err_sched_fini;
> +
> + mair =
> io_pgtable_ops_to_pgtable(vm->pgtbl_ops)->cfg.arm_lpae_s1_cfg.mair;
> + vm->memattr = mair_to_memattr(mair);
> +
> + mutex_lock(&ptdev->mmu->vm.lock);
> + list_add_tail(&vm->node, &ptdev->mmu->vm.list);
> +
> + /* If a reset is in progress, stop the scheduler. */
> + if (ptdev->mmu->vm.reset_in_progress)
> + panthor_vm_stop(vm);
> + mutex_unlock(&ptdev->mmu->vm.lock);
> +
> + /* We intentionally leave the reserved range to zero, because we want
> kernel VMAs
> + * to be handled the same way user VMAs are.
> + */
> + drm_gpuvm_init(&vm->base,
> + for_mcu ? "panthor-MCU-VM" : "panthor-GPU-VM",
> + 0, &ptdev->base, dummy_gem, min_va, va_range, 0, 0,
> + &panthor_gpuvm_ops);
> + drm_gem_object_put(dummy_gem);
> + return vm;
> +
> +err_sched_fini:
> + drm_sched_fini(&vm->sched);
> +
> +err_free_io_pgtable:
> + free_io_pgtable_ops(vm->pgtbl_ops);
> +
> +err_mm_takedown:
> + drm_mm_takedown(&vm->mm);
> + drm_gem_object_put(dummy_gem);
> +
> +err_free_vm:
> + kfree(vm);
> + return ERR_PTR(ret);
> +}
> +
> +static int
> +panthor_vm_bind_prepare_op_ctx(struct drm_file *file,
> + struct panthor_vm *vm,
> + const struct drm_panthor_vm_bind_op *op,
> + struct panthor_vm_op_ctx *op_ctx)
> +{
> + struct drm_gem_object *gem;
> + int ret;
> +
> + /* Aligned on page size. */
> + if ((op->va | op->size) & ~PAGE_MASK)
> + return -EINVAL;
> +
> + switch (op->flags & DRM_PANTHOR_VM_BIND_OP_TYPE_MASK) {
> + case DRM_PANTHOR_VM_BIND_OP_TYPE_MAP:
> + gem = drm_gem_object_lookup(file, op->bo_handle);
> + ret = panthor_vm_prepare_map_op_ctx(op_ctx, vm,
> + gem ? to_panthor_bo(gem) :
> NULL,
> + op->bo_offset,
> + op->size,
> + op->va,
> + op->flags);
> + drm_gem_object_put(gem);
> + return ret;
> +
> + case DRM_PANTHOR_VM_BIND_OP_TYPE_UNMAP:
> + if (op->flags & ~DRM_PANTHOR_VM_BIND_OP_TYPE_MASK)
> + return -EINVAL;
> +
> + if (op->bo_handle || op->bo_offset)
> + return -EINVAL;
> +
> + return panthor_vm_prepare_unmap_op_ctx(op_ctx, vm, op->va,
> op->size);
> +
> + case DRM_PANTHOR_VM_BIND_OP_TYPE_SYNC_ONLY:
> + if (op->flags & ~DRM_PANTHOR_VM_BIND_OP_TYPE_MASK)
> + return -EINVAL;
> +
> + if (op->bo_handle || op->bo_offset)
> + return -EINVAL;
> +
> + if (op->va || op->size)
> + return -EINVAL;
> +
> + if (!op->syncs.count)
> + return -EINVAL;
> +
> + panthor_vm_prepare_sync_only_op_ctx(op_ctx, vm);
> + return 0;
> +
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static void panthor_vm_bind_job_cleanup_op_ctx_work(struct work_struct *work)
> +{
> + struct panthor_vm_bind_job *job =
> + container_of(work, struct panthor_vm_bind_job,
> cleanup_op_ctx_work);
> +
> + panthor_vm_cleanup_op_ctx(&job->ctx, job->vm);
> + panthor_vm_bind_job_put(&job->base);
> +}
> +
> +/**
> + * panthor_vm_bind_job_create() - Create a VM_BIND job
> + * @file: File.
> + * @vm: VM targeted by the VM_BIND job.
> + * @op: VM operation data.
> + *
> + * Return: A valid pointer on success, an ERR_PTR() otherwise.
> + */
> +struct drm_sched_job *
> +panthor_vm_bind_job_create(struct drm_file *file,
> + struct panthor_vm *vm,
> + const struct drm_panthor_vm_bind_op *op)
> +{
> + struct panthor_vm_bind_job *job;
> + int ret;
> +
> + if (!vm)
> + return ERR_PTR(-EINVAL);
> +
> + if (vm->destroyed || vm->unusable)
> + return ERR_PTR(-EINVAL);
> +
> + job = kzalloc(sizeof(*job), GFP_KERNEL);
> + if (!job)
> + return ERR_PTR(-ENOMEM);
> +
> + ret = panthor_vm_bind_prepare_op_ctx(file, vm, op, &job->ctx);
> + if (ret) {
> + kfree(job);
> + return ERR_PTR(ret);
> + }
> +
> + INIT_WORK(&job->cleanup_op_ctx_work,
> panthor_vm_bind_job_cleanup_op_ctx_work);
> + kref_init(&job->refcount);
> + job->vm = panthor_vm_get(vm);
> +
> + ret = drm_sched_job_init(&job->base, &vm->entity, 1, vm);
> + if (ret)
> + goto err_put_job;
> +
> + return &job->base;
> +
> +err_put_job:
> + panthor_vm_bind_job_put(&job->base);
> + return ERR_PTR(ret);
> +}
> +
> +/**
> + * panthor_vm_bind_job_prepare_resvs() - Prepare VM_BIND job dma_resvs
> + * @exec: The locking/preparation context.
> + * @sched_job: The job to prepare resvs on.
> + *
> + * Locks and prepare the VM resv.
> + *
> + * If this is a map operation, locks and prepares the GEM resv.
> + *
> + * Return: 0 on success, a negative error code otherwise.
> + */
> +int panthor_vm_bind_job_prepare_resvs(struct drm_exec *exec,
> + struct drm_sched_job *sched_job)
> +{
> + struct panthor_vm_bind_job *job = container_of(sched_job, struct
> panthor_vm_bind_job, base);
> + int ret;
> +
> + /* Acquire the VM lock an reserve a slot for this VM bind job. */
> + ret = drm_gpuvm_prepare_vm(&job->vm->base, exec, 1);
> + if (ret)
> + return ret;
> +
> + if (job->ctx.map.vm_bo) {
> + /* Lock/prepare the GEM being mapped. */
> + ret = drm_exec_prepare_obj(exec, job->ctx.map.vm_bo->obj, 1);
> + if (ret)
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +/**
> + * panthor_vm_bind_job_update_resvs() - Update the resv objects touched by a
> job
> + * @exec: drm_exec context.
> + * @sched_job: Job to update the resvs on.
> + */
> +void panthor_vm_bind_job_update_resvs(struct drm_exec *exec,
> + struct drm_sched_job *sched_job)
> +{
> + struct panthor_vm_bind_job *job = container_of(sched_job, struct
> panthor_vm_bind_job, base);
> +
> + /* Explicit sync => we just register our job finished fence as
> bookkeep. */
> + drm_gpuvm_resv_add_fence(&job->vm->base, exec,
> + &sched_job->s_fence->finished,
> + DMA_RESV_USAGE_BOOKKEEP,
> + DMA_RESV_USAGE_BOOKKEEP);
> +}
> +
> +void panthor_vm_update_resvs(struct panthor_vm *vm, struct drm_exec *exec,
> + struct dma_fence *fence,
> + enum dma_resv_usage private_usage,
> + enum dma_resv_usage extobj_usage)
> +{
> + drm_gpuvm_resv_add_fence(&vm->base, exec, fence, private_usage,
> extobj_usage);
> +}
> +
> +/**
> + * panthor_vm_bind_exec_sync_op() - Execute a VM_BIND operation
> synchronously.
> + * @file: File.
> + * @vm: VM targeted by the VM operation.
> + * @op: Data describing the VM operation.
> + *
> + * Return: 0 on success, a negative error code otherwise.
> + */
> +int panthor_vm_bind_exec_sync_op(struct drm_file *file,
> + struct panthor_vm *vm,
> + struct drm_panthor_vm_bind_op *op)
> +{
> + struct panthor_vm_op_ctx op_ctx;
> + int ret;
> +
> + /* No sync objects allowed on synchronous operations. */
> + if (op->syncs.count)
> + return -EINVAL;
> +
> + if (!op->size)
> + return 0;
> +
> + ret = panthor_vm_bind_prepare_op_ctx(file, vm, op, &op_ctx);
> + if (ret)
> + return ret;
> +
> + ret = panthor_vm_exec_op(vm, &op_ctx, false);
> + panthor_vm_cleanup_op_ctx(&op_ctx, vm);
> +
> + return ret;
> +}
> +
> +/**
> + * panthor_vm_map_bo_range() - Map a GEM object range to a VM
> + * @vm: VM to map the GEM to.
> + * @bo: GEM object to map.
> + * @offset: Offset in the GEM object.
> + * @size: Size to map.
> + * @va: Virtual address to map the object to.
> + * @flags: Combination of drm_panthor_vm_bind_op_flags flags.
> + * Only map-related flags are valid.
> + *
> + * Internal use only. For userspace requests, use
> + * panthor_vm_bind_exec_sync_op() instead.
> + *
> + * Return: 0 on success, a negative error code otherwise.
> + */
> +int panthor_vm_map_bo_range(struct panthor_vm *vm, struct panthor_gem_object
> *bo,
> + u64 offset, u64 size, u64 va, u32 flags)
> +{
> + struct panthor_vm_op_ctx op_ctx;
> + int ret;
> +
> + ret = panthor_vm_prepare_map_op_ctx(&op_ctx, vm, bo, offset, size, va,
> flags);
> + if (ret)
> + return ret;
> +
> + ret = panthor_vm_exec_op(vm, &op_ctx, false);
> + panthor_vm_cleanup_op_ctx(&op_ctx, vm);
> +
> + return ret;
> +}
> +
> +/**
> + * panthor_vm_unmap_range() - Unmap a portion of the VA space
> + * @vm: VM to unmap the region from.
> + * @va: Virtual address to unmap. Must be 4k aligned.
> + * @size: Size of the region to unmap. Must be 4k aligned.
> + *
> + * Internal use only. For userspace requests, use
> + * panthor_vm_bind_exec_sync_op() instead.
> + *
> + * Return: 0 on success, a negative error code otherwise.
> + */
> +int panthor_vm_unmap_range(struct panthor_vm *vm, u64 va, u64 size)
> +{
> + struct panthor_vm_op_ctx op_ctx;
> + int ret;
> +
> + ret = panthor_vm_prepare_unmap_op_ctx(&op_ctx, vm, va, size);
> + if (ret)
> + return ret;
> +
> + ret = panthor_vm_exec_op(vm, &op_ctx, false);
> + panthor_vm_cleanup_op_ctx(&op_ctx, vm);
> +
> + return ret;
> +}
> +
> +/**
> + * panthor_vm_prepare_mapped_bos_resvs() - Prepare resvs on VM BOs.
> + * @exec: Locking/preparation context.
> + * @vm: VM targeted by the GPU job.
> + * @slot_count: Number of slots to reserve.
> + *
> + * GPU jobs assume all BOs bound to the VM at the time the job is submitted
> + * are available when the job is executed. In order to guarantee that, we
> + * need to reserve a slot on all BOs mapped to a VM and update this slot with
> + * the job fence after its submission.
> + *
> + * Return: 0 on success, a negative error code otherwise.
> + */
> +int panthor_vm_prepare_mapped_bos_resvs(struct drm_exec *exec, struct
> panthor_vm *vm,
> + u32 slot_count)
> +{
> + int ret;
> +
> + /* Acquire the VM lock an reserve a slot for this GPU job. */
> + ret = drm_gpuvm_prepare_vm(&vm->base, exec, slot_count);
> + if (ret)
> + return ret;
> +
> + /* VM operations are not protected by the VM resv-lock. We need to
> + * take the op_lock to make sure the shared_bos list is not updated
> + * while we're walking it.
> + */
Is the above comment stale? AFAIK the shared_bos list doesn't exist
anymore and this doesn't appear to relate to anything here.
Steve
> + return drm_gpuvm_prepare_objects(&vm->base, exec, slot_count);
> +}
> +
> +/**
> + * panthor_mmu_unplug() - Unplug the MMU logic
> + * @ptdev: Device.
> + *
> + * No access to the MMU regs should be done after this function is called.
> + * We suspend the IRQ and disable all VMs to guarantee that.
> + */
> +void panthor_mmu_unplug(struct panthor_device *ptdev)
> +{
> + panthor_mmu_irq_suspend(&ptdev->mmu->irq);
> +
> + mutex_lock(&ptdev->mmu->as.slots_lock);
> + for (u32 i = 0; i < ARRAY_SIZE(ptdev->mmu->as.slots); i++) {
> + struct panthor_vm *vm = ptdev->mmu->as.slots[i].vm;
> +
> + if (vm) {
> + drm_WARN_ON(&ptdev->base, panthor_mmu_as_disable(ptdev,
> i));
> + vm->as.id = -1;
> + list_del_init(&vm->as.lru_node);
> + clear_bit(i, &ptdev->mmu->as.alloc_mask);
> + ptdev->mmu->as.slots[i].vm = NULL;
> + }
> + }
> + mutex_unlock(&ptdev->mmu->as.slots_lock);
> +}
> +
> +static void panthor_mmu_release_wq(struct drm_device *ddev, void *res)
> +{
> + destroy_workqueue(res);
> +}
> +
> +/**
> + * panthor_mmu_init() - Initialize the MMU logic.
> + * @ptdev: Device.
> + *
> + * Return: 0 on success, a negative error code otherwise.
> + */
> +int panthor_mmu_init(struct panthor_device *ptdev)
> +{
> + struct panthor_mmu *mmu;
> + int ret, irq;
> +
> + mmu = drmm_kzalloc(&ptdev->base, sizeof(*mmu), GFP_KERNEL);
> + if (!mmu)
> + return -ENOMEM;
> +
> + INIT_LIST_HEAD(&mmu->as.lru_list);
> +
> + drmm_mutex_init(&ptdev->base, &mmu->as.slots_lock);
> + INIT_LIST_HEAD(&mmu->vm.list);
> + drmm_mutex_init(&ptdev->base, &mmu->vm.lock);
> +
> + ptdev->mmu = mmu;
> +
> + irq = platform_get_irq_byname(to_platform_device(ptdev->base.dev),
> "mmu");
> + if (irq <= 0)
> + return -ENODEV;
> +
> + ret = panthor_request_mmu_irq(ptdev, &mmu->irq, irq,
> + panthor_mmu_fault_mask(ptdev, ~0));
> + if (ret)
> + return ret;
> +
> + mmu->vm.wq = alloc_workqueue("panthor-vm-bind", WQ_UNBOUND, 0);
> + if (!mmu->vm.wq)
> + return -ENOMEM;
> +
> + return drmm_add_action_or_reset(&ptdev->base, panthor_mmu_release_wq,
> mmu->vm.wq);
> +}
> +
> +#ifdef CONFIG_DEBUG_FS
> +static int show_vm_gpuvas(struct panthor_vm *vm, struct seq_file *m)
> +{
> + int ret;
> +
> + mutex_lock(&vm->op_lock);
> + ret = drm_debugfs_gpuva_info(m, &vm->base);
> + mutex_unlock(&vm->op_lock);
> +
> + return ret;
> +}
> +
> +static int show_each_vm(struct seq_file *m, void *arg)
> +{
> + struct drm_info_node *node = (struct drm_info_node *)m->private;
> + struct drm_device *ddev = node->minor->dev;
> + struct panthor_device *ptdev = container_of(ddev, struct
> panthor_device, base);
> + int (*show)(struct panthor_vm *, struct seq_file *) =
> node->info_ent->data;
> + struct panthor_vm *vm;
> + int ret = 0;
> +
> + mutex_lock(&ptdev->mmu->vm.lock);
> + list_for_each_entry(vm, &ptdev->mmu->vm.list, node) {
> + ret = show(vm, m);
> + if (ret < 0)
> + break;
> +
> + seq_puts(m, "\n");
> + }
> + mutex_unlock(&ptdev->mmu->vm.lock);
> +
> + return ret;
> +}
> +
> +static struct drm_info_list panthor_mmu_debugfs_list[] = {
> + DRM_DEBUGFS_GPUVA_INFO(show_each_vm, show_vm_gpuvas),
> +};
> +
> +/**
> + * panthor_mmu_debugfs_init() - Initialize MMU debugfs entries
> + * @minor: Minor.
> + */
> +void panthor_mmu_debugfs_init(struct drm_minor *minor)
> +{
> + drm_debugfs_create_files(panthor_mmu_debugfs_list,
> + ARRAY_SIZE(panthor_mmu_debugfs_list),
> + minor->debugfs_root, minor);
> +}
> +#endif /* CONFIG_DEBUG_FS */
> +
> +/**
> + * panthor_mmu_pt_cache_init() - Initialize the page table cache.
> + *
> + * Return: 0 on success, a negative error code otherwise.
> + */
> +int panthor_mmu_pt_cache_init(void)
> +{
> + pt_cache = kmem_cache_create("panthor-mmu-pt", SZ_4K, SZ_4K, 0, NULL);
> + if (!pt_cache)
> + return -ENOMEM;
> +
> + return 0;
> +}
> +
> +/**
> + * panthor_mmu_pt_cache_fini() - Destroy the page table cache.
> + */
> +void panthor_mmu_pt_cache_fini(void)
> +{
> + kmem_cache_destroy(pt_cache);
> +}
> diff --git a/drivers/gpu/drm/panthor/panthor_mmu.h
> b/drivers/gpu/drm/panthor/panthor_mmu.h
> new file mode 100644
> index 000000000000..cc142877470e
> --- /dev/null
> +++ b/drivers/gpu/drm/panthor/panthor_mmu.h
> @@ -0,0 +1,101 @@
> +/* SPDX-License-Identifier: GPL-2.0 or MIT */
> +/* Copyright 2019 Linaro, Ltd, Rob Herring <r...@kernel.org> */
> +/* Copyright 2023 Collabora ltd. */
> +
> +#ifndef __PANTHOR_MMU_H__
> +#define __PANTHOR_MMU_H__
> +
> +#include <linux/dma-resv.h>
> +
> +struct drm_exec;
> +struct drm_sched_job;
> +struct panthor_gem_object;
> +struct panthor_heap_pool;
> +struct panthor_vm;
> +struct panthor_vma;
> +struct panthor_mmu;
> +
> +int panthor_mmu_init(struct panthor_device *ptdev);
> +void panthor_mmu_unplug(struct panthor_device *ptdev);
> +void panthor_mmu_pre_reset(struct panthor_device *ptdev);
> +void panthor_mmu_post_reset(struct panthor_device *ptdev);
> +void panthor_mmu_suspend(struct panthor_device *ptdev);
> +void panthor_mmu_resume(struct panthor_device *ptdev);
> +
> +int panthor_vm_map_bo_range(struct panthor_vm *vm, struct panthor_gem_object
> *bo,
> + u64 offset, u64 size, u64 va, u32 flags);
> +int panthor_vm_unmap_range(struct panthor_vm *vm, u64 va, u64 size);
> +struct panthor_gem_object *
> +panthor_vm_get_bo_for_va(struct panthor_vm *vm, u64 va, u64 *bo_offset);
> +
> +int panthor_vm_active(struct panthor_vm *vm);
> +void panthor_vm_idle(struct panthor_vm *vm);
> +int panthor_vm_as(struct panthor_vm *vm);
> +
> +struct panthor_heap_pool *
> +panthor_vm_get_heap_pool(struct panthor_vm *vm, bool create);
> +
> +struct panthor_vm *panthor_vm_get(struct panthor_vm *vm);
> +void panthor_vm_put(struct panthor_vm *vm);
> +struct panthor_vm *panthor_vm_create(struct panthor_device *ptdev, bool
> for_mcu,
> + u64 kernel_va_start, u64 kernel_va_size,
> + u64 kernel_auto_va_start,
> + u64 kernel_auto_va_size);
> +
> +int panthor_vm_prepare_mapped_bos_resvs(struct drm_exec *exec,
> + struct panthor_vm *vm,
> + u32 slot_count);
> +int panthor_vm_add_bos_resvs_deps_to_job(struct panthor_vm *vm,
> + struct drm_sched_job *job);
> +void panthor_vm_add_job_fence_to_bos_resvs(struct panthor_vm *vm,
> + struct drm_sched_job *job);
> +
> +struct dma_resv *panthor_vm_resv(struct panthor_vm *vm);
> +struct drm_gem_object *panthor_vm_root_gem(struct panthor_vm *vm);
> +
> +void panthor_vm_pool_destroy(struct panthor_file *pfile);
> +int panthor_vm_pool_create(struct panthor_file *pfile);
> +int panthor_vm_pool_create_vm(struct panthor_device *ptdev,
> + struct panthor_vm_pool *pool,
> + struct drm_panthor_vm_create *args);
> +int panthor_vm_pool_destroy_vm(struct panthor_vm_pool *pool, u32 handle);
> +struct panthor_vm *panthor_vm_pool_get_vm(struct panthor_vm_pool *pool, u32
> handle);
> +
> +bool panthor_vm_has_unhandled_faults(struct panthor_vm *vm);
> +
> +/*
> + * PANTHOR_VM_KERNEL_AUTO_VA: Use this magic address when you want the GEM
> + * logic to auto-allocate the virtual address in the reserved kernel VA
> range.
> + */
> +#define PANTHOR_VM_KERNEL_AUTO_VA ~0ull
> +
> +int panthor_vm_alloc_va(struct panthor_vm *vm, u64 va, u64 size,
> + struct drm_mm_node *va_node);
> +void panthor_vm_free_va(struct panthor_vm *vm, struct drm_mm_node *va_node);
> +
> +int panthor_vm_bind_exec_sync_op(struct drm_file *file,
> + struct panthor_vm *vm,
> + struct drm_panthor_vm_bind_op *op);
> +
> +struct drm_sched_job *
> +panthor_vm_bind_job_create(struct drm_file *file,
> + struct panthor_vm *vm,
> + const struct drm_panthor_vm_bind_op *op);
> +void panthor_vm_bind_job_put(struct drm_sched_job *job);
> +int panthor_vm_bind_job_prepare_resvs(struct drm_exec *exec,
> + struct drm_sched_job *job);
> +void panthor_vm_bind_job_update_resvs(struct drm_exec *exec, struct
> drm_sched_job *job);
> +
> +void panthor_vm_update_resvs(struct panthor_vm *vm, struct drm_exec *exec,
> + struct dma_fence *fence,
> + enum dma_resv_usage private_usage,
> + enum dma_resv_usage extobj_usage);
> +
> +int panthor_mmu_pt_cache_init(void);
> +void panthor_mmu_pt_cache_fini(void);
> +
> +#ifdef CONFIG_DEBUG_FS
> +void panthor_mmu_debugfs_init(struct drm_minor *minor);
> +#endif
> +
> +#endif
