From: Sanjay R Mehta <sanju.me...@amd.com> Register ptdma queue to Linux dmaengine framework as general-purpose DMA channels.
Signed-off-by: Sanjay R Mehta <sanju.me...@amd.com> --- drivers/dma/ptdma/Kconfig | 2 + drivers/dma/ptdma/Makefile | 2 +- drivers/dma/ptdma/ptdma-dev.c | 32 ++ drivers/dma/ptdma/ptdma-dmaengine.c | 561 ++++++++++++++++++++++++++++++++++++ drivers/dma/ptdma/ptdma.h | 31 ++ 5 files changed, 627 insertions(+), 1 deletion(-) create mode 100644 drivers/dma/ptdma/ptdma-dmaengine.c diff --git a/drivers/dma/ptdma/Kconfig b/drivers/dma/ptdma/Kconfig index f93f9c2..694ed27 100644 --- a/drivers/dma/ptdma/Kconfig +++ b/drivers/dma/ptdma/Kconfig @@ -2,6 +2,8 @@ config AMD_PTDMA tristate "AMD PassThru DMA Engine" depends on X86_64 && PCI + select DMA_ENGINE + select DMA_VIRTUAL_CHANNELS help Enable support for the AMD PTDMA controller. This controller provides DMA capabilities & performs high bandwidth memory to diff --git a/drivers/dma/ptdma/Makefile b/drivers/dma/ptdma/Makefile index 320fa82..a528cb0 100644 --- a/drivers/dma/ptdma/Makefile +++ b/drivers/dma/ptdma/Makefile @@ -5,6 +5,6 @@ obj-$(CONFIG_AMD_PTDMA) += ptdma.o -ptdma-objs := ptdma-dev.o +ptdma-objs := ptdma-dev.o ptdma-dmaengine.o ptdma-$(CONFIG_PCI) += ptdma-pci.o diff --git a/drivers/dma/ptdma/ptdma-dev.c b/drivers/dma/ptdma/ptdma-dev.c index d1e9892..4bdad35 100644 --- a/drivers/dma/ptdma/ptdma-dev.c +++ b/drivers/dma/ptdma/ptdma-dev.c @@ -127,6 +127,26 @@ static inline void pt_core_enable_queue_interrupts(struct pt_device *pt) iowrite32(SUPPORTED_INTERRUPTS, pt->cmd_q.reg_int_enable); } +static void pt_do_cmd_complete(unsigned long data) +{ + struct pt_tasklet_data *tdata = (struct pt_tasklet_data *)data; + struct pt_cmd *cmd = tdata->cmd; + struct pt_cmd_queue *cmd_q = &cmd->pt->cmd_q; + u32 tail; + + tail = lower_32_bits(cmd_q->qdma_tail + cmd_q->qidx * Q_DESC_SIZE); + if (cmd_q->cmd_error) { + /* + * Log the error and flush the queue by + * moving the head pointer + */ + pt_log_error(cmd_q->pt, cmd_q->cmd_error); + iowrite32(tail, cmd_q->reg_head_lo); + } + + cmd->pt_cmd_callback(cmd->data, cmd->ret); +} + static irqreturn_t pt_core_irq_handler(int irq, void *data) { struct pt_device *pt = (struct pt_device *)data; @@ -150,6 +170,7 @@ static irqreturn_t pt_core_irq_handler(int irq, void *data) } pt_core_enable_queue_interrupts(pt); + pt_do_cmd_complete((ulong)&pt->tdata); return IRQ_HANDLED; } @@ -253,8 +274,16 @@ int pt_core_init(struct pt_device *pt) pt_core_enable_queue_interrupts(pt); + /* Register the DMA engine support */ + ret = pt_dmaengine_register(pt); + if (ret) + goto e_dmaengine; + return 0; +e_dmaengine: + free_irq(pt->pt_irq, pt); + e_dma_alloc: dma_free_coherent(dev, cmd_q->qsize, cmd_q->qbase, cmd_q->qbase_dma); @@ -270,6 +299,9 @@ void pt_core_destroy(struct pt_device *pt) struct pt_cmd_queue *cmd_q = &pt->cmd_q; struct pt_cmd *cmd; + /* Unregister the DMA engine */ + pt_dmaengine_unregister(pt); + /* Disable and clear interrupts */ pt_core_disable_queue_interrupts(pt); diff --git a/drivers/dma/ptdma/ptdma-dmaengine.c b/drivers/dma/ptdma/ptdma-dmaengine.c new file mode 100644 index 0000000..bc9c580 --- /dev/null +++ b/drivers/dma/ptdma/ptdma-dmaengine.c @@ -0,0 +1,561 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * AMD Passthrough DMA device driver + * -- Based on the CCP driver + * + * Copyright (C) 2016,2020 Advanced Micro Devices, Inc. + * + * Author: Sanjay R Mehta <sanju.me...@amd.com> + * Author: Gary R Hook <gary.h...@amd.com> + */ + +#include "ptdma.h" +#include "../dmaengine.h" +#include "../virt-dma.h" + +#define PT_DMA_WIDTH(_mask) \ +({ \ + u64 mask = (_mask) + 1; \ + (mask == 0) ? 64 : fls64(mask); \ +}) + +static inline struct pt_dma_chan *to_pt_chan(struct dma_chan *dma_chan) +{ + return container_of(dma_chan, struct pt_dma_chan, vc.chan); +} + +static inline struct pt_dma_desc *to_pt_desc(struct virt_dma_desc *vd) +{ + return container_of(vd, struct pt_dma_desc, vd); +} + +static void pt_free_cmd_resources(struct pt_device *pt, + struct list_head *list) +{ + struct pt_dma_cmd *cmd, *ctmp; + + list_for_each_entry_safe(cmd, ctmp, list, entry) { + list_del(&cmd->entry); + kmem_cache_free(pt->dma_cmd_cache, cmd); + } +} + +static void pt_free_chan_resources(struct dma_chan *dma_chan) +{ + struct pt_dma_chan *chan = to_pt_chan(dma_chan); + + vchan_free_chan_resources(&chan->vc); +} + +static void pt_synchronize(struct dma_chan *dma_chan) +{ + struct pt_dma_chan *chan = to_pt_chan(dma_chan); + + vchan_synchronize(&chan->vc); +} + +static void pt_do_cleanup(struct virt_dma_desc *vd) +{ + struct pt_dma_desc *desc = to_pt_desc(vd); + struct pt_device *pt = desc->pt; + struct dma_chan *dma_chan; + struct pt_dma_chan *chan; + + dma_chan = desc->vd.tx.chan; + chan = to_pt_chan(dma_chan); + + pt_free_cmd_resources(pt, &desc->cmdlist); + kmem_cache_free(pt->dma_desc_cache, desc); +} + +static int pt_issue_next_cmd(struct pt_dma_desc *desc) +{ + struct pt_passthru_engine *pt_engine; + struct pt_dma_cmd *cmd; + struct pt_device *pt; + struct pt_cmd *pt_cmd; + struct pt_cmd_queue *cmd_q; + + cmd = list_first_entry(&desc->cmdlist, struct pt_dma_cmd, entry); + desc->issued_to_hw = 1; + + pt_cmd = &cmd->pt_cmd; + pt = pt_cmd->pt; + cmd_q = &pt->cmd_q; + pt_engine = &pt_cmd->passthru; + + pt->tdata.cmd = pt_cmd; + + /* Execute the command */ + pt_cmd->ret = pt_core_perform_passthru(cmd_q, pt_engine); + + return 0; +} + +static void pt_free_active_cmd(struct pt_dma_desc *desc) +{ + struct pt_dma_cmd *cmd = NULL; + + if (desc->issued_to_hw) + cmd = list_first_entry_or_null(&desc->cmdlist, struct pt_dma_cmd, + entry); + if (!cmd) + return; + + list_del(&cmd->entry); + kmem_cache_free(desc->pt->dma_cmd_cache, cmd); +} + +static struct pt_dma_desc *pt_next_dma_desc(struct pt_dma_chan *chan) +{ + /* Get the next DMA descriptor on the active list */ + struct virt_dma_desc *vd = vchan_next_desc(&chan->vc); + + return vd ? to_pt_desc(vd) : NULL; +} + +static struct pt_dma_desc *__pt_next_dma_desc(struct pt_dma_chan *chan) +{ + /* Get the next DMA descriptor on the active list */ + struct virt_dma_desc *vd = vchan_next_desc(&chan->vc); + + if (list_empty(&chan->vc.desc_submitted)) + return NULL; + + vd = list_empty(&chan->vc.desc_issued) ? + list_first_entry(&chan->vc.desc_submitted, + struct virt_dma_desc, node) : NULL; + + vchan_issue_pending(&chan->vc); + + return vd ? to_pt_desc(vd) : NULL; +} + +static struct pt_dma_desc *pt_handle_active_desc(struct pt_dma_chan *chan, + struct pt_dma_desc *desc) +{ + struct dma_async_tx_descriptor *tx_desc; + struct virt_dma_desc *vd; + unsigned long flags; + + /* Loop over descriptors until one is found with commands */ + do { + if (desc) { + /* Remove the DMA command from the list and free it */ + pt_free_active_cmd(desc); + if (!desc->issued_to_hw) { + /* No errors, keep going */ + if (desc->status != DMA_ERROR) + return desc; + /* Error, free remaining commands and move on */ + pt_free_cmd_resources(desc->pt, + &desc->cmdlist); + } + + tx_desc = &desc->vd.tx; + vd = &desc->vd; + } else { + tx_desc = NULL; + } + + spin_lock_irqsave(&chan->vc.lock, flags); + + if (desc) { + if (desc->status != DMA_ERROR) + desc->status = DMA_COMPLETE; + + dma_cookie_complete(tx_desc); + dma_descriptor_unmap(tx_desc); + list_del(&desc->vd.node); + } + + desc = pt_next_dma_desc(chan); + + spin_unlock_irqrestore(&chan->vc.lock, flags); + + if (tx_desc) { + dmaengine_desc_get_callback_invoke(tx_desc, NULL); + dma_run_dependencies(tx_desc); + vchan_vdesc_fini(vd); + } + } while (desc); + + return NULL; +} + +static void pt_cmd_callback(void *data, int err) +{ + struct pt_dma_desc *desc = data; + struct dma_chan *dma_chan; + struct pt_dma_chan *chan; + int ret; + + if (err == -EINPROGRESS) + return; + + dma_chan = desc->vd.tx.chan; + chan = to_pt_chan(dma_chan); + + if (err) + desc->status = DMA_ERROR; + + while (true) { + /* Check for DMA descriptor completion */ + desc = pt_handle_active_desc(chan, desc); + + /* Don't submit cmd if no descriptor or DMA is paused */ + if (!desc) + break; + + ret = pt_issue_next_cmd(desc); + if (!ret) + break; + + desc->status = DMA_ERROR; + } +} + +static struct pt_dma_cmd *pt_alloc_dma_cmd(struct pt_dma_chan *chan) +{ + struct pt_dma_cmd *cmd; + + cmd = kmem_cache_zalloc(chan->pt->dma_cmd_cache, GFP_NOWAIT); + + return cmd; +} + +static struct pt_dma_desc *pt_alloc_dma_desc(struct pt_dma_chan *chan, + unsigned long flags) +{ + struct pt_dma_desc *desc; + + desc = kmem_cache_zalloc(chan->pt->dma_desc_cache, GFP_NOWAIT); + if (!desc) + return NULL; + + vchan_tx_prep(&chan->vc, &desc->vd, flags); + + desc->pt = chan->pt; + desc->issued_to_hw = 0; + INIT_LIST_HEAD(&desc->cmdlist); + desc->status = DMA_IN_PROGRESS; + + return desc; +} + +static struct pt_dma_desc *pt_create_desc(struct dma_chan *dma_chan, + struct scatterlist *dst_sg, + unsigned int dst_nents, + struct scatterlist *src_sg, + unsigned int src_nents, + unsigned long flags) +{ + struct pt_dma_chan *chan = to_pt_chan(dma_chan); + struct pt_device *pt = chan->pt; + struct pt_dma_desc *desc; + struct pt_dma_cmd *cmd; + struct pt_cmd *pt_cmd; + struct pt_passthru_engine *pt_engine; + unsigned int src_offset, src_len; + unsigned int dst_offset, dst_len; + unsigned int len; + size_t total_len; + + if (!dst_sg || !src_sg) + return NULL; + + if (!dst_nents || !src_nents) + return NULL; + + desc = pt_alloc_dma_desc(chan, flags); + if (!desc) + return NULL; + + total_len = 0; + + src_len = sg_dma_len(src_sg); + src_offset = 0; + + dst_len = sg_dma_len(dst_sg); + dst_offset = 0; + + while (true) { + if (!src_len) { + src_nents--; + if (!src_nents) + break; + + src_sg = sg_next(src_sg); + if (!src_sg) + break; + + src_len = sg_dma_len(src_sg); + src_offset = 0; + continue; + } + + if (!dst_len) { + dst_nents--; + if (!dst_nents) + break; + + dst_sg = sg_next(dst_sg); + if (!dst_sg) + break; + + dst_len = sg_dma_len(dst_sg); + dst_offset = 0; + continue; + } + + len = min(dst_len, src_len); + + cmd = pt_alloc_dma_cmd(chan); + if (!cmd) + goto err; + + pt_cmd = &cmd->pt_cmd; + pt_cmd->pt = chan->pt; + pt_engine = &pt_cmd->passthru; + pt_cmd->engine = PT_ENGINE_PASSTHRU; + pt_engine->src_dma = sg_dma_address(src_sg) + src_offset; + pt_engine->dst_dma = sg_dma_address(dst_sg) + dst_offset; + pt_engine->src_len = len; + pt_cmd->pt_cmd_callback = pt_cmd_callback; + pt_cmd->data = desc; + + list_add_tail(&cmd->entry, &desc->cmdlist); + + total_len += len; + + src_len -= len; + src_offset += len; + + dst_len -= len; + dst_offset += len; + } + + desc->len = total_len; + + if (list_empty(&desc->cmdlist)) + goto err; + + return desc; + +err: + pt_free_cmd_resources(pt, &desc->cmdlist); + kmem_cache_free(pt->dma_desc_cache, desc); + + return NULL; +} + +static struct dma_async_tx_descriptor * +pt_prep_dma_memcpy(struct dma_chan *dma_chan, dma_addr_t dst, + dma_addr_t src, size_t len, unsigned long flags) +{ + struct scatterlist dst_sg, src_sg; + struct pt_dma_desc *desc; + + sg_init_table(&dst_sg, 1); + sg_dma_address(&dst_sg) = dst; + sg_dma_len(&dst_sg) = len; + + sg_init_table(&src_sg, 1); + sg_dma_address(&src_sg) = src; + sg_dma_len(&src_sg) = len; + + desc = pt_create_desc(dma_chan, &dst_sg, 1, &src_sg, 1, flags); + if (!desc) + return NULL; + + return &desc->vd.tx; +} + +static struct dma_async_tx_descriptor * +pt_prep_dma_interrupt(struct dma_chan *dma_chan, unsigned long flags) +{ + struct pt_dma_chan *chan = to_pt_chan(dma_chan); + struct pt_dma_desc *desc; + + desc = pt_alloc_dma_desc(chan, flags); + if (!desc) + return NULL; + + return &desc->vd.tx; +} + +static void pt_issue_pending(struct dma_chan *dma_chan) +{ + struct pt_dma_chan *chan = to_pt_chan(dma_chan); + struct pt_dma_desc *desc; + unsigned long flags; + + spin_lock_irqsave(&chan->vc.lock, flags); + + desc = __pt_next_dma_desc(chan); + + spin_unlock_irqrestore(&chan->vc.lock, flags); + + /* If there was nothing active, start processing */ + if (desc) + pt_cmd_callback(desc, 0); +} + +static enum dma_status pt_tx_status(struct dma_chan *dma_chan, + dma_cookie_t cookie, + struct dma_tx_state *state) +{ + struct pt_dma_chan *chan = to_pt_chan(dma_chan); + struct pt_dma_desc *desc; + enum dma_status ret; + unsigned long flags; + struct virt_dma_desc *vd; + + ret = dma_cookie_status(dma_chan, cookie, state); + if (ret == DMA_COMPLETE) + return ret; + + spin_lock_irqsave(&chan->vc.lock, flags); + vd = vchan_find_desc(&chan->vc, cookie); + desc = vd ? to_pt_desc(vd) : NULL; + ret = desc->status; + spin_unlock_irqrestore(&chan->vc.lock, flags); + + return ret; +} + +static int pt_pause(struct dma_chan *dma_chan) +{ + struct pt_dma_chan *chan = to_pt_chan(dma_chan); + unsigned long flags; + + spin_lock_irqsave(&chan->vc.lock, flags); + pt_stop_queue(&chan->pt->cmd_q); + spin_unlock_irqrestore(&chan->vc.lock, flags); + + return 0; +} + +static int pt_resume(struct dma_chan *dma_chan) +{ + struct pt_dma_chan *chan = to_pt_chan(dma_chan); + struct pt_dma_desc *desc = NULL; + unsigned long flags; + + spin_lock_irqsave(&chan->vc.lock, flags); + pt_start_queue(&chan->pt->cmd_q); + desc = __pt_next_dma_desc(chan); + spin_unlock_irqrestore(&chan->vc.lock, flags); + + /* If there was something active, re-start */ + if (desc) + pt_cmd_callback(desc, 0); + + return 0; +} + +static int pt_terminate_all(struct dma_chan *dma_chan) +{ + struct pt_dma_chan *chan = to_pt_chan(dma_chan); + + vchan_free_chan_resources(&chan->vc); + + return 0; +} + +int pt_dmaengine_register(struct pt_device *pt) +{ + struct pt_dma_chan *chan; + struct dma_device *dma_dev = &pt->dma_dev; + struct dma_chan *dma_chan; + char *dma_cmd_cache_name; + char *dma_desc_cache_name; + int ret; + + pt->pt_dma_chan = devm_kzalloc(pt->dev, sizeof(*pt->pt_dma_chan), + GFP_KERNEL); + if (!pt->pt_dma_chan) + return -ENOMEM; + + dma_cmd_cache_name = devm_kasprintf(pt->dev, GFP_KERNEL, + "%s-dmaengine-cmd-cache", + pt->name); + if (!dma_cmd_cache_name) + return -ENOMEM; + + pt->dma_cmd_cache = kmem_cache_create(dma_cmd_cache_name, + sizeof(struct pt_dma_cmd), + sizeof(void *), + SLAB_HWCACHE_ALIGN, NULL); + if (!pt->dma_cmd_cache) + return -ENOMEM; + + dma_desc_cache_name = devm_kasprintf(pt->dev, GFP_KERNEL, + "%s-dmaengine-desc-cache", + pt->name); + if (!dma_desc_cache_name) { + ret = -ENOMEM; + goto err_cache; + } + + pt->dma_desc_cache = kmem_cache_create(dma_desc_cache_name, + sizeof(struct pt_dma_desc), + sizeof(void *), + SLAB_HWCACHE_ALIGN, NULL); + if (!pt->dma_desc_cache) { + ret = -ENOMEM; + goto err_cache; + } + + dma_dev->dev = pt->dev; + dma_dev->src_addr_widths = PT_DMA_WIDTH(dma_get_mask(pt->dev)); + dma_dev->dst_addr_widths = PT_DMA_WIDTH(dma_get_mask(pt->dev)); + dma_dev->directions = DMA_MEM_TO_MEM; + dma_dev->residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR; + dma_cap_set(DMA_MEMCPY, dma_dev->cap_mask); + dma_cap_set(DMA_INTERRUPT, dma_dev->cap_mask); + dma_cap_set(DMA_PRIVATE, dma_dev->cap_mask); + + INIT_LIST_HEAD(&dma_dev->channels); + + chan = pt->pt_dma_chan; + chan->pt = pt; + dma_chan = &chan->vc.chan; + + dma_dev->device_free_chan_resources = pt_free_chan_resources; + dma_dev->device_prep_dma_memcpy = pt_prep_dma_memcpy; + dma_dev->device_prep_dma_interrupt = pt_prep_dma_interrupt; + dma_dev->device_issue_pending = pt_issue_pending; + dma_dev->device_tx_status = pt_tx_status; + dma_dev->device_pause = pt_pause; + dma_dev->device_resume = pt_resume; + dma_dev->device_terminate_all = pt_terminate_all; + dma_dev->device_synchronize = pt_synchronize; + + chan->vc.desc_free = pt_do_cleanup; + vchan_init(&chan->vc, dma_dev); + + ret = dma_async_device_register(dma_dev); + if (ret) + goto err_reg; + + return 0; + +err_reg: + kmem_cache_destroy(pt->dma_desc_cache); + +err_cache: + kmem_cache_destroy(pt->dma_cmd_cache); + + return ret; +} + +void pt_dmaengine_unregister(struct pt_device *pt) +{ + struct dma_device *dma_dev = &pt->dma_dev; + + dma_async_device_unregister(dma_dev); + + kmem_cache_destroy(pt->dma_desc_cache); + kmem_cache_destroy(pt->dma_cmd_cache); +} diff --git a/drivers/dma/ptdma/ptdma.h b/drivers/dma/ptdma/ptdma.h index 9e5819f..67c24bd 100644 --- a/drivers/dma/ptdma/ptdma.h +++ b/drivers/dma/ptdma/ptdma.h @@ -20,6 +20,9 @@ #include <linux/list.h> #include <linux/wait.h> #include <linux/dmapool.h> +#include <linux/dmaengine.h> + +#include "../virt-dma.h" #define MAX_PT_NAME_LEN 16 #define MAX_DMAPOOL_NAME_LEN 32 @@ -172,6 +175,25 @@ struct pt_cmd { void *data; }; +struct pt_dma_cmd { + struct list_head entry; + struct pt_cmd pt_cmd; +}; + +struct pt_dma_desc { + struct virt_dma_desc vd; + struct pt_device *pt; + struct list_head cmdlist; + enum dma_status status; + size_t len; + bool issued_to_hw; +}; + +struct pt_dma_chan { + struct virt_dma_chan vc; + struct pt_device *pt; +}; + struct pt_cmd_queue { struct pt_device *pt; @@ -240,6 +262,12 @@ struct pt_device { */ struct pt_cmd_queue cmd_q; + /* Support for the DMA Engine capabilities */ + struct dma_device dma_dev; + struct pt_dma_chan *pt_dma_chan; + struct kmem_cache *dma_cmd_cache; + struct kmem_cache *dma_desc_cache; + wait_queue_head_t lsb_queue; struct pt_tasklet_data tdata; @@ -304,6 +332,9 @@ struct pt_dev_vdata { const unsigned int bar; }; +int pt_dmaengine_register(struct pt_device *pt); +void pt_dmaengine_unregister(struct pt_device *pt); + int pt_core_init(struct pt_device *pt); void pt_core_destroy(struct pt_device *pt); -- 2.7.4