On 9/15/2023 5:56 PM, Zeng, Oak wrote:
Thanks, Oak-----Original Message----- From: Das, Nirmoy <nirmoy....@intel.com> Sent: Friday, September 15, 2023 4:34 AM To: intel-gfx@lists.freedesktop.org Cc: Zeng, Oak <oak.z...@intel.com>; chris.p.wil...@linux.intel.com; Piorkowski, Piotr <piotr.piorkow...@intel.com>; Shyti, Andi <andi.sh...@intel.com>; Mun, Gwan-gyeong <gwan-gyeong....@intel.com>; Roper, Matthew D <matthew.d.ro...@intel.com>; Das, Nirmoy <nirmoy....@intel.com> Subject: [PATCH 5/7] drm/i915: Implement GGTT update method with MI_UPDATE_GTT Implement GGTT update method with blitter command, MI_UPDATE_GTT and install those handlers if a platform requires that. v2: Make sure we hold the GT wakeref and Blitter engine wakeref before we call mutex_lock/intel_context_enter below. When GT/engine are not awake, the intel_context_enter calls into some runtime pm function which can end up with kmalloc/fs_reclaim. But trigger fs_reclaim holding a mutex lock is not allowed because shrinker can also try to hold the same mutex lock. It is a circular lock. So hold the GT/blitter engine wakeref before calling mutex_lock, to fix the circular lock. Signed-off-by: Nirmoy Das <nirmoy....@intel.com> Signed-off-by: Oak Zeng <oak.z...@intel.com> --- drivers/gpu/drm/i915/gt/intel_ggtt.c | 235 +++++++++++++++++++++++++++ 1 file changed, 235 insertions(+) diff --git a/drivers/gpu/drm/i915/gt/intel_ggtt.c b/drivers/gpu/drm/i915/gt/intel_ggtt.c index dd0ed941441a..b94de7cebfce 100644 --- a/drivers/gpu/drm/i915/gt/intel_ggtt.c +++ b/drivers/gpu/drm/i915/gt/intel_ggtt.c @@ -15,18 +15,23 @@ #include "display/intel_display.h" #include "gem/i915_gem_lmem.h" +#include "intel_context.h" #include "intel_ggtt_gmch.h" +#include "intel_gpu_commands.h" #include "intel_gt.h" #include "intel_gt_regs.h" #include "intel_pci_config.h" +#include "intel_ring.h" #include "i915_drv.h" #include "i915_pci.h" +#include "i915_request.h" #include "i915_scatterlist.h" #include "i915_utils.h" #include "i915_vgpu.h" #include "intel_gtt.h" #include "gen8_ppgtt.h" +#include "intel_engine_pm.h" static void i915_ggtt_color_adjust(const struct drm_mm_node *node, unsigned long color, @@ -252,6 +257,145 @@ u64 gen8_ggtt_pte_encode(dma_addr_t addr, return pte; } +static bool should_update_ggtt_with_bind(struct i915_ggtt *ggtt) +{ + struct intel_gt *gt = ggtt->vm.gt; + + return intel_gt_is_bind_context_ready(gt); +} + +static struct intel_context *gen8_ggtt_bind_get_ce(struct i915_ggtt *ggtt) +{ + struct intel_context *ce; + struct intel_gt *gt = ggtt->vm.gt; + + if (intel_gt_is_wedged(gt)) + return NULL; + + ce = gt->engine[BCS0]->bind_context; + GEM_BUG_ON(!ce); + + /* + * If the GT is not awake already at this stage then fallback + * to pci based GGTT update otherwise __intel_wakeref_get_first() + * would conflict with fs_reclaim trying to allocate memory while + * doing rpm_resume(). + */ + if (!intel_gt_pm_get_if_awake(gt)) + return NULL; + + intel_engine_pm_get(ce->engine); + + return ce; +} + +static void gen8_ggtt_bind_put_ce(struct intel_context *ce) +{ + intel_engine_pm_put(ce->engine); + intel_gt_pm_put(ce->engine->gt); +} + +static bool gen8_ggtt_bind_ptes(struct i915_ggtt *ggtt, u32 offset, + struct sg_table *pages, u32 num_entries, + const gen8_pte_t pte) +{ + struct i915_sched_attr attr = {}; + struct intel_gt *gt = ggtt->vm.gt; + const gen8_pte_t scratch_pte = ggtt->vm.scratch[0]->encode; + struct sgt_iter iter; + struct i915_request *rq; + struct intel_context *ce; + u32 *cs; + + if (!num_entries) + return true; + + ce = gen8_ggtt_bind_get_ce(ggtt); + if (!ce) + return false; + + if (pages) + iter = __sgt_iter(pages->sgl, true); + + while (num_entries) { + int count = 0; + dma_addr_t addr; + /* + * MI_UPDATE_GTT can update 512 entries in a single command but + * that end up with engine reset, 511 works. + */ + u32 n_ptes = min_t(u32, 511, num_entries); + + if (mutex_lock_interruptible(&ce->timeline->mutex)) + goto put_ce; + + intel_context_enter(ce); + rq = __i915_request_create(ce, GFP_NOWAIT | GFP_ATOMIC); + intel_context_exit(ce); + if (IS_ERR(rq)) { + GT_TRACE(gt, "Failed to get bind request\n"); + mutex_unlock(&ce->timeline->mutex); + goto put_ce; + } + + cs = intel_ring_begin(rq, 2 * n_ptes + 2); + if (IS_ERR(cs)) { + GT_TRACE(gt, "Failed to ring space for GGTT bind\n"); + i915_request_set_error_once(rq, PTR_ERR(cs)); + /* once a request is created, it must be queued */ + goto queue_err_rq; + } + + *cs++ = MI_UPDATE_GTT | (2 * n_ptes); + *cs++ = offset << 12; + + if (pages) { + for_each_sgt_daddr_next(addr, iter) { + if (count == n_ptes) + break; + *cs++ = lower_32_bits(pte | addr); + *cs++ = upper_32_bits(pte | addr); + count++; + } + /* fill remaining with scratch pte, if any */ + if (count < n_ptes) { + memset64((u64 *)cs, scratch_pte, + n_ptes - count); + cs += (n_ptes - count) * 2; + }Should we return error instead of silently fill pte with scratch? Or maybe even gem_bug_on on this case? The caller didn't allocate enough pages, means something wrong happened...
We do the dame already in gen8_ggtt_insert_entries() so not adding something new here. The comment just made it obvious :) I don't know the exact usecase when this happens but
I saw tons of pipe error without this. Regards, Nirmoy
Oak+ } else { + memset64((u64 *)cs, pte, n_ptes); + cs += n_ptes * 2; + } + + intel_ring_advance(rq, cs); +queue_err_rq: + i915_request_get(rq); + __i915_request_commit(rq); + __i915_request_queue(rq, &attr); + + mutex_unlock(&ce->timeline->mutex); + /* This will break if the request is complete or after engine reset */ + i915_request_wait(rq, 0, MAX_SCHEDULE_TIMEOUT); + if (rq->fence.error) + goto err_rq; + + i915_request_put(rq); + + num_entries -= n_ptes; + offset += n_ptes; + } + + gen8_ggtt_bind_put_ce(ce); + return true; + +err_rq: + i915_request_put(rq); +put_ce: + gen8_ggtt_bind_put_ce(ce); + return false; +} + static void gen8_set_pte(void __iomem *addr, gen8_pte_t pte) { writeq(pte, addr); @@ -272,6 +416,21 @@ static void gen8_ggtt_insert_page(struct i915_address_space *vm, ggtt->invalidate(ggtt); } +static void gen8_ggtt_insert_page_bind(struct i915_address_space *vm, + dma_addr_t addr, u64 offset, + unsigned int pat_index, u32 flags) +{ + struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm); + gen8_pte_t pte; + + pte = ggtt->vm.pte_encode(addr, pat_index, flags); + if (should_update_ggtt_with_bind(i915_vm_to_ggtt(vm)) && + gen8_ggtt_bind_ptes(ggtt, offset, NULL, 1, pte)) + return ggtt->invalidate(ggtt); + + gen8_ggtt_insert_page(vm, addr, offset, pat_index, flags); +} + static void gen8_ggtt_insert_entries(struct i915_address_space *vm, struct i915_vma_resource *vma_res, unsigned int pat_index, @@ -311,6 +470,50 @@ static void gen8_ggtt_insert_entries(struct i915_address_space *vm, ggtt->invalidate(ggtt); } +static bool __gen8_ggtt_insert_entries_bind(struct i915_address_space *vm, + struct i915_vma_resource *vma_res, + unsigned int pat_index, u32 flags) +{ + struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm); + gen8_pte_t scratch_pte = vm->scratch[0]->encode; + gen8_pte_t pte_encode; + u64 start, end; + + pte_encode = ggtt->vm.pte_encode(0, pat_index, flags); + start = (vma_res->start - vma_res->guard) / I915_GTT_PAGE_SIZE; + end = start + vma_res->guard / I915_GTT_PAGE_SIZE; + if (!gen8_ggtt_bind_ptes(ggtt, start, NULL, end - start, scratch_pte)) + goto err; + + start = end; + end += (vma_res->node_size + vma_res->guard) / I915_GTT_PAGE_SIZE; + if (!gen8_ggtt_bind_ptes(ggtt, start, vma_res->bi.pages, + vma_res->node_size / I915_GTT_PAGE_SIZE, pte_encode)) + goto err; + + start += vma_res->node_size / I915_GTT_PAGE_SIZE; + if (!gen8_ggtt_bind_ptes(ggtt, start, NULL, end - start, scratch_pte)) + goto err; + + return true; + +err: + return false; +} + +static void gen8_ggtt_insert_entries_bind(struct i915_address_space *vm, + struct i915_vma_resource *vma_res, + unsigned int pat_index, u32 flags) +{ + struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm); + + if (should_update_ggtt_with_bind(i915_vm_to_ggtt(vm)) && + __gen8_ggtt_insert_entries_bind(vm, vma_res, pat_index, flags)) + return ggtt->invalidate(ggtt); + + gen8_ggtt_insert_entries(vm, vma_res, pat_index, flags); +} + static void gen8_ggtt_clear_range(struct i915_address_space *vm, u64 start, u64 length) { @@ -332,6 +535,27 @@ static void gen8_ggtt_clear_range(struct i915_address_space *vm, gen8_set_pte(>t_base[i], scratch_pte); } +static void gen8_ggtt_scratch_range_bind(struct i915_address_space *vm, + u64 start, u64 length) +{ + struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm); + unsigned int first_entry = start / I915_GTT_PAGE_SIZE; + unsigned int num_entries = length / I915_GTT_PAGE_SIZE; + const gen8_pte_t scratch_pte = vm->scratch[0]->encode; + const int max_entries = ggtt_total_entries(ggtt) - first_entry; + + if (WARN(num_entries > max_entries, + "First entry = %d; Num entries = %d (max=%d)\n", + first_entry, num_entries, max_entries)) + num_entries = max_entries; + + if (should_update_ggtt_with_bind(ggtt) && gen8_ggtt_bind_ptes(ggtt, first_entry, + NULL, num_entries, scratch_pte)) + return ggtt->invalidate(ggtt); + + gen8_ggtt_clear_range(vm, start, length); +} + static void gen6_ggtt_insert_page(struct i915_address_space *vm, dma_addr_t addr, u64 offset, @@ -997,6 +1221,17 @@ static int gen8_gmch_probe(struct i915_ggtt *ggtt) I915_VMA_GLOBAL_BIND | I915_VMA_LOCAL_BIND; } + if (i915_ggtt_require_binder(i915)) { + ggtt->vm.scratch_range = gen8_ggtt_scratch_range_bind; + ggtt->vm.insert_page = gen8_ggtt_insert_page_bind; + ggtt->vm.insert_entries = gen8_ggtt_insert_entries_bind; + /* + * On GPU is hung, we might bind VMAs for error capture. + * Fallback to CPU GGTT updates in that case. + */ + ggtt->vm.raw_insert_page = gen8_ggtt_insert_page; + } + if (intel_uc_wants_guc(&ggtt->vm.gt->uc)) ggtt->invalidate = guc_ggtt_invalidate; else -- 2.41.0
