[PATCH v6 1/2] drm/amdgpu: implement TLB flush fence
Shashank Sharma
shashank.sharma at amd.com
Fri Mar 15 13:25:10 UTC 2024
From: Christian Koenig <christian.koenig at amd.com>
The problem is that when (for example) 4k pages are replaced
with a single 2M page we need to wait for change to be flushed
out by invalidating the TLB before the PT can be freed.
Solve this by moving the TLB flush into a DMA-fence object which
can be used to delay the freeing of the PT BOs until it is signaled.
Also remove existing TLB flush cb and vm->last_tlb_flush fence and
replace it with new method of flushing tlb.
V2: (Shashank)
- rebase
- set dma_fence_error only in case of error
- add tlb_flush fence only when PT/PD BO is locked (Felix)
- use vm->pasid when f is NULL (Mukul)
V4: - add a wait for (f->dependency) in tlb_fence_work (Christian)
- move the misplaced fence_create call to the end (Philip)
V5: - free the f->dependency properly (Christian)
V6: (Shashank)
- added some cleanup from the HW seq patch in this patch.
- introduce params.needs_flush and its usage in this patch.
- remove vm->last_tlb_flush and tlb_cb.
- rebase without TLB HW seq patch.
Cc: Christian Koenig <christian.koenig at amd.com>
Cc: Felix Kuehling <Felix.Kuehling at amd.com>
Cc: Rajneesh Bhardwaj <rajneesh.bhardwaj at amd.com>
Cc: Alex Deucher <alexander.deucher at amd.com>
Acked-by: Felix Kuehling <Felix.Kuehling at amd.com>
Acked-by: Rajneesh Bhardwaj <rajneesh.bhardwaj at amd.com>
Tested-by: Rajneesh Bhardwaj <rajneesh.bhardwaj at amd.com>
Reviewed-by: Shashank Sharma <shashank.sharma at amd.com>
Signed-off-by: Christian König <christian.koenig at amd.com>
Signed-off-by: Shashank Sharma <shashank.sharma at amd.com>
---
drivers/gpu/drm/amd/amdgpu/Makefile | 3 +-
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 77 ++----------
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h | 26 ++--
drivers/gpu/drm/amd/amdgpu/amdgpu_vm_cpu.c | 4 +-
drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c | 2 +-
drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c | 4 +
.../gpu/drm/amd/amdgpu/amdgpu_vm_tlb_fence.c | 112 ++++++++++++++++++
7 files changed, 141 insertions(+), 87 deletions(-)
create mode 100644 drivers/gpu/drm/amd/amdgpu/amdgpu_vm_tlb_fence.c
diff --git a/drivers/gpu/drm/amd/amdgpu/Makefile b/drivers/gpu/drm/amd/amdgpu/Makefile
index 4536c8ad0e11..f24f11ac3e92 100644
--- a/drivers/gpu/drm/amd/amdgpu/Makefile
+++ b/drivers/gpu/drm/amd/amdgpu/Makefile
@@ -70,7 +70,8 @@ amdgpu-y += amdgpu_device.o amdgpu_doorbell_mgr.o amdgpu_kms.o \
amdgpu_cs.o amdgpu_bios.o amdgpu_benchmark.o \
atombios_dp.o amdgpu_afmt.o amdgpu_trace_points.o \
atombios_encoders.o amdgpu_sa.o atombios_i2c.o \
- amdgpu_dma_buf.o amdgpu_vm.o amdgpu_vm_pt.o amdgpu_ib.o amdgpu_pll.o \
+ amdgpu_dma_buf.o amdgpu_vm.o amdgpu_vm_pt.o amdgpu_vm_tlb_fence.o \
+ amdgpu_ib.o amdgpu_pll.o \
amdgpu_ucode.o amdgpu_bo_list.o amdgpu_ctx.o amdgpu_sync.o \
amdgpu_gtt_mgr.o amdgpu_preempt_mgr.o amdgpu_vram_mgr.o amdgpu_virt.o \
amdgpu_atomfirmware.o amdgpu_vf_error.o amdgpu_sched.o \
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index 81fb3465e197..3b64623f32ea 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -111,21 +111,6 @@ struct amdgpu_prt_cb {
struct dma_fence_cb cb;
};
-/**
- * struct amdgpu_vm_tlb_seq_struct - Helper to increment the TLB flush sequence
- */
-struct amdgpu_vm_tlb_seq_struct {
- /**
- * @vm: pointer to the amdgpu_vm structure to set the fence sequence on
- */
- struct amdgpu_vm *vm;
-
- /**
- * @cb: callback
- */
- struct dma_fence_cb cb;
-};
-
/**
* amdgpu_vm_set_pasid - manage pasid and vm ptr mapping
*
@@ -868,23 +853,6 @@ int amdgpu_vm_update_pdes(struct amdgpu_device *adev,
return r;
}
-/**
- * amdgpu_vm_tlb_seq_cb - make sure to increment tlb sequence
- * @fence: unused
- * @cb: the callback structure
- *
- * Increments the tlb sequence to make sure that future CS execute a VM flush.
- */
-static void amdgpu_vm_tlb_seq_cb(struct dma_fence *fence,
- struct dma_fence_cb *cb)
-{
- struct amdgpu_vm_tlb_seq_struct *tlb_cb;
-
- tlb_cb = container_of(cb, typeof(*tlb_cb), cb);
- atomic64_inc(&tlb_cb->vm->tlb_seq);
- kfree(tlb_cb);
-}
-
/**
* amdgpu_vm_update_range - update a range in the vm page table
*
@@ -917,7 +885,6 @@ int amdgpu_vm_update_range(struct amdgpu_device *adev, struct amdgpu_vm *vm,
struct dma_fence **fence)
{
struct amdgpu_vm_update_params params;
- struct amdgpu_vm_tlb_seq_struct *tlb_cb;
struct amdgpu_res_cursor cursor;
enum amdgpu_sync_mode sync_mode;
int r, idx;
@@ -925,12 +892,6 @@ int amdgpu_vm_update_range(struct amdgpu_device *adev, struct amdgpu_vm *vm,
if (!drm_dev_enter(adev_to_drm(adev), &idx))
return -ENODEV;
- tlb_cb = kmalloc(sizeof(*tlb_cb), GFP_KERNEL);
- if (!tlb_cb) {
- r = -ENOMEM;
- goto error_unlock;
- }
-
/* Vega20+XGMI where PTEs get inadvertently cached in L2 texture cache,
* heavy-weight flush TLB unconditionally.
*/
@@ -948,6 +909,7 @@ int amdgpu_vm_update_range(struct amdgpu_device *adev, struct amdgpu_vm *vm,
params.immediate = immediate;
params.pages_addr = pages_addr;
params.unlocked = unlocked;
+ params.needs_flush = flush_tlb;
params.allow_override = allow_override;
/* Implicitly sync to command submissions in the same VM before
@@ -961,7 +923,7 @@ int amdgpu_vm_update_range(struct amdgpu_device *adev, struct amdgpu_vm *vm,
amdgpu_vm_eviction_lock(vm);
if (vm->evicting) {
r = -EBUSY;
- goto error_free;
+ goto error_unlock;
}
if (!unlocked && !dma_fence_is_signaled(vm->last_unlocked)) {
@@ -974,7 +936,7 @@ int amdgpu_vm_update_range(struct amdgpu_device *adev, struct amdgpu_vm *vm,
r = vm->update_funcs->prepare(¶ms, resv, sync_mode);
if (r)
- goto error_free;
+ goto error_unlock;
amdgpu_res_first(pages_addr ? NULL : res, offset,
(last - start + 1) * AMDGPU_GPU_PAGE_SIZE, &cursor);
@@ -1024,7 +986,7 @@ int amdgpu_vm_update_range(struct amdgpu_device *adev, struct amdgpu_vm *vm,
tmp = start + num_entries;
r = amdgpu_vm_ptes_update(¶ms, start, tmp, addr, flags);
if (r)
- goto error_free;
+ goto error_unlock;
amdgpu_res_next(&cursor, num_entries * AMDGPU_GPU_PAGE_SIZE);
start = tmp;
@@ -1032,21 +994,14 @@ int amdgpu_vm_update_range(struct amdgpu_device *adev, struct amdgpu_vm *vm,
r = vm->update_funcs->commit(¶ms, fence);
- if (flush_tlb || params.table_freed) {
- tlb_cb->vm = vm;
- if (fence && *fence &&
- !dma_fence_add_callback(*fence, &tlb_cb->cb,
- amdgpu_vm_tlb_seq_cb)) {
- dma_fence_put(vm->last_tlb_flush);
- vm->last_tlb_flush = dma_fence_get(*fence);
- } else {
- amdgpu_vm_tlb_seq_cb(NULL, &tlb_cb->cb);
- }
- tlb_cb = NULL;
- }
+ /* Prepare a TLB flush fence to be attached to PTs */
+ if (!unlocked && params.needs_flush && vm->is_compute_context) {
+ amdgpu_vm_tlb_fence_create(adev, vm, fence);
-error_free:
- kfree(tlb_cb);
+ /* Makes sure no PD/PT is freed before the flush */
+ dma_resv_add_fence(vm->root.bo->tbo.base.resv, *fence,
+ DMA_RESV_USAGE_BOOKKEEP);
+ }
error_unlock:
amdgpu_vm_eviction_unlock(vm);
@@ -2386,11 +2341,11 @@ int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm,
vm->last_update = dma_fence_get_stub();
vm->last_unlocked = dma_fence_get_stub();
- vm->last_tlb_flush = dma_fence_get_stub();
vm->generation = 0;
mutex_init(&vm->eviction_lock);
vm->evicting = false;
+ vm->tlb_fence_context = dma_fence_context_alloc(1);
r = amdgpu_vm_pt_create(adev, vm, adev->vm_manager.root_level,
false, &root, xcp_id);
@@ -2429,10 +2384,8 @@ int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm,
amdgpu_bo_unref(&root_bo);
error_free_delayed:
- dma_fence_put(vm->last_tlb_flush);
dma_fence_put(vm->last_unlocked);
amdgpu_vm_fini_entities(vm);
-
return r;
}
@@ -2530,7 +2483,6 @@ void amdgpu_vm_fini(struct amdgpu_device *adev, struct amdgpu_vm *vm)
struct amdgpu_bo_va_mapping *mapping, *tmp;
bool prt_fini_needed = !!adev->gmc.gmc_funcs->set_prt;
struct amdgpu_bo *root;
- unsigned long flags;
int i;
amdgpu_amdkfd_gpuvm_destroy_cb(adev, vm);
@@ -2543,11 +2495,6 @@ void amdgpu_vm_fini(struct amdgpu_device *adev, struct amdgpu_vm *vm)
amdgpu_vm_set_pasid(adev, vm, 0);
dma_fence_wait(vm->last_unlocked, false);
dma_fence_put(vm->last_unlocked);
- dma_fence_wait(vm->last_tlb_flush, false);
- /* Make sure that all fence callbacks have completed */
- spin_lock_irqsave(vm->last_tlb_flush->lock, flags);
- spin_unlock_irqrestore(vm->last_tlb_flush->lock, flags);
- dma_fence_put(vm->last_tlb_flush);
list_for_each_entry_safe(mapping, tmp, &vm->freed, list) {
if (mapping->flags & AMDGPU_PTE_PRT && prt_fini_needed) {
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
index 8efa8422f4f7..ba92f431f4e0 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
@@ -257,9 +257,9 @@ struct amdgpu_vm_update_params {
unsigned int num_dw_left;
/**
- * @table_freed: return true if page table is freed when updating
+ * @needs_flush: true whenever we need to invalidate the TLB
*/
- bool table_freed;
+ bool needs_flush;
/**
* @allow_override: true for memory that is not uncached: allows MTYPE
@@ -338,10 +338,10 @@ struct amdgpu_vm {
struct drm_sched_entity immediate;
struct drm_sched_entity delayed;
- /* Last finished delayed update */
+ /* Sequence number indicating necessary TLB flush */
atomic64_t tlb_seq;
- struct dma_fence *last_tlb_flush;
atomic64_t kfd_last_flushed_seq;
+ uint64_t tlb_fence_context;
/* How many times we had to re-generate the page tables */
uint64_t generation;
@@ -562,21 +562,6 @@ int amdgpu_vm_pt_map_tables(struct amdgpu_device *adev, struct amdgpu_vm *vm);
*/
static inline uint64_t amdgpu_vm_tlb_seq(struct amdgpu_vm *vm)
{
- unsigned long flags;
- spinlock_t *lock;
-
- /*
- * Workaround to stop racing between the fence signaling and handling
- * the cb. The lock is static after initially setting it up, just make
- * sure that the dma_fence structure isn't freed up.
- */
- rcu_read_lock();
- lock = vm->last_tlb_flush->lock;
- rcu_read_unlock();
-
- spin_lock_irqsave(lock, flags);
- spin_unlock_irqrestore(lock, flags);
-
return atomic64_read(&vm->tlb_seq);
}
@@ -611,5 +596,8 @@ void amdgpu_vm_update_fault_cache(struct amdgpu_device *adev,
uint64_t addr,
uint32_t status,
unsigned int vmhub);
+void amdgpu_vm_tlb_fence_create(struct amdgpu_device *adev,
+ struct amdgpu_vm *vm,
+ struct dma_fence **fence);
#endif
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_cpu.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_cpu.c
index 6e31621452de..3895bd7d176a 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_cpu.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_cpu.c
@@ -108,7 +108,9 @@ static int amdgpu_vm_cpu_update(struct amdgpu_vm_update_params *p,
static int amdgpu_vm_cpu_commit(struct amdgpu_vm_update_params *p,
struct dma_fence **fence)
{
- /* Flush HDP */
+ if (p->needs_flush)
+ atomic64_inc(&p->vm->tlb_seq);
+
mb();
amdgpu_device_flush_hdp(p->adev, NULL);
return 0;
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c
index 124389a6bf48..601df0ce8290 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c
@@ -972,7 +972,7 @@ int amdgpu_vm_ptes_update(struct amdgpu_vm_update_params *params,
while (cursor.pfn < frag_start) {
/* Make sure previous mapping is freed */
if (cursor.entry->bo) {
- params->table_freed = true;
+ params->needs_flush = true;
amdgpu_vm_pt_free_dfs(adev, params->vm,
&cursor,
params->unlocked);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c
index 349416e176a1..66e8a016126b 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c
@@ -126,6 +126,10 @@ static int amdgpu_vm_sdma_commit(struct amdgpu_vm_update_params *p,
WARN_ON(ib->length_dw == 0);
amdgpu_ring_pad_ib(ring, ib);
+
+ if (p->needs_flush)
+ atomic64_inc(&p->vm->tlb_seq);
+
WARN_ON(ib->length_dw > p->num_dw_left);
f = amdgpu_job_submit(p->job);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_tlb_fence.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_tlb_fence.c
new file mode 100644
index 000000000000..51cddfa3f1e8
--- /dev/null
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_tlb_fence.c
@@ -0,0 +1,112 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+/*
+ * Copyright 2023 Advanced Micro Devices, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <linux/dma-fence.h>
+#include <linux/workqueue.h>
+
+#include "amdgpu.h"
+#include "amdgpu_vm.h"
+#include "amdgpu_gmc.h"
+
+struct amdgpu_tlb_fence {
+ struct dma_fence base;
+ struct amdgpu_device *adev;
+ struct dma_fence *dependency;
+ struct work_struct work;
+ spinlock_t lock;
+ uint16_t pasid;
+
+};
+
+static const char *amdgpu_tlb_fence_get_driver_name(struct dma_fence *fence)
+{
+ return "amdgpu tlb fence";
+}
+
+static const char *amdgpu_tlb_fence_get_timeline_name(struct dma_fence *f)
+{
+ return "amdgpu tlb timeline";
+}
+
+static void amdgpu_tlb_fence_work(struct work_struct *work)
+{
+ struct amdgpu_tlb_fence *f = container_of(work, typeof(*f), work);
+ int r;
+
+ if (f->dependency) {
+ dma_fence_wait(f->dependency, false);
+ dma_fence_put(f->dependency);
+ f->dependency = NULL;
+ }
+
+ r = amdgpu_gmc_flush_gpu_tlb_pasid(f->adev, f->pasid, 2, true, 0);
+ if (r) {
+ dev_err(f->adev->dev, "TLB flush failed for PASID %d.\n",
+ f->pasid);
+ dma_fence_set_error(&f->base, r);
+ }
+
+ dma_fence_signal(&f->base);
+ dma_fence_put(&f->base);
+}
+
+static const struct dma_fence_ops amdgpu_tlb_fence_ops = {
+ .use_64bit_seqno = true,
+ .get_driver_name = amdgpu_tlb_fence_get_driver_name,
+ .get_timeline_name = amdgpu_tlb_fence_get_timeline_name
+};
+
+void amdgpu_vm_tlb_fence_create(struct amdgpu_device *adev, struct amdgpu_vm *vm,
+ struct dma_fence **fence)
+{
+ struct amdgpu_tlb_fence *f;
+
+ f = kmalloc(sizeof(*f), GFP_KERNEL);
+ if (!f) {
+ /*
+ * We can't fail since the PDEs and PTEs are already updated, so
+ * just block for the dependency and execute the TLB flush
+ */
+ if (*fence)
+ dma_fence_wait(*fence, false);
+
+ amdgpu_gmc_flush_gpu_tlb_pasid(adev, vm->pasid, 2, true, 0);
+ *fence = dma_fence_get_stub();
+ return;
+ }
+
+ f->adev = adev;
+ f->dependency = *fence;
+ f->pasid = vm->pasid;
+ INIT_WORK(&f->work, amdgpu_tlb_fence_work);
+ spin_lock_init(&f->lock);
+
+ dma_fence_init(&f->base, &amdgpu_tlb_fence_ops, &f->lock,
+ vm->tlb_fence_context, atomic64_read(&vm->tlb_seq));
+
+ /* TODO: We probably need a separate wq here */
+ dma_fence_get(&f->base);
+ schedule_work(&f->work);
+
+ *fence = &f->base;
+}
--
2.43.2
More information about the amd-gfx
mailing list