[PATCH 4/9] drm/amdgpu: Add multi-GPU DMA mapping helpers
Felix Kuehling
Felix.Kuehling at amd.com
Wed Apr 14 06:46:16 UTC 2021
Add BO-type specific helpers functions to DMA-map and unmap
kfd_mem_attachments. Implement this functionality for userptrs by creating
one SG BO per GPU and filling it with a DMA mapping of the pages from the
original mem->bo.
Signed-off-by: Felix Kuehling <Felix.Kuehling at amd.com>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h | 8 +-
.../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c | 155 ++++++++++++++++--
2 files changed, 152 insertions(+), 11 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
index 910c50956e16..fc3514ed1b74 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
@@ -38,11 +38,17 @@ extern uint64_t amdgpu_amdkfd_total_mem_size;
struct amdgpu_device;
+enum kfd_mem_attachment_type {
+ KFD_MEM_ATT_SHARED, /* Share kgd_mem->bo or another attachment's */
+ KFD_MEM_ATT_USERPTR, /* SG bo to DMA map pages from a userptr bo */
+};
+
struct kfd_mem_attachment {
struct list_head list;
+ enum kfd_mem_attachment_type type;
+ bool is_mapped;
struct amdgpu_bo_va *bo_va;
struct amdgpu_device *adev;
- bool is_mapped;
uint64_t va;
uint64_t pte_flags;
};
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
index 114fbf508707..51502a07fc1d 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
@@ -471,12 +471,117 @@ static uint64_t get_pte_flags(struct amdgpu_device *adev, struct kgd_mem *mem)
return pte_flags;
}
+static int
+kfd_mem_dmamap_userptr(struct kgd_mem *mem,
+ struct kfd_mem_attachment *attachment)
+{
+ enum dma_data_direction direction =
+ mem->alloc_flags & KFD_IOC_ALLOC_MEM_FLAGS_WRITABLE ?
+ DMA_BIDIRECTIONAL : DMA_TO_DEVICE;
+ struct ttm_operation_ctx ctx = {.interruptible = true};
+ struct amdgpu_bo *bo = attachment->bo_va->base.bo;
+ struct amdgpu_device *adev = attachment->adev;
+ struct ttm_tt *src_ttm = mem->bo->tbo.ttm;
+ struct ttm_tt *ttm = bo->tbo.ttm;
+ int ret;
+
+ ttm->sg = kmalloc(sizeof(*ttm->sg), GFP_KERNEL);
+ if (unlikely(!ttm->sg))
+ return -ENOMEM;
+
+ if (WARN_ON(ttm->num_pages != src_ttm->num_pages))
+ return -EINVAL;
+
+ /* Same sequence as in amdgpu_ttm_tt_pin_userptr */
+ ret = sg_alloc_table_from_pages(ttm->sg, src_ttm->pages,
+ ttm->num_pages, 0,
+ (u64)ttm->num_pages << PAGE_SHIFT,
+ GFP_KERNEL);
+ if (unlikely(ret))
+ goto release_sg;
+
+ ret = dma_map_sgtable(adev->dev, ttm->sg, direction, 0);
+ if (unlikely(ret))
+ goto release_sg;
+
+ drm_prime_sg_to_dma_addr_array(ttm->sg, ttm->dma_address,
+ ttm->num_pages);
+
+ amdgpu_bo_placement_from_domain(bo, AMDGPU_GEM_DOMAIN_GTT);
+ ret = ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
+ if (ret)
+ goto release_sg;
+
+ return 0;
+
+release_sg:
+ pr_err("DMA map userptr failed: %d\n", ret);
+ sg_free_table(ttm->sg);
+ kfree(ttm->sg);
+ ttm->sg = NULL;
+ return ret;
+}
+
+static int
+kfd_mem_dmamap_attachment(struct kgd_mem *mem,
+ struct kfd_mem_attachment *attachment)
+{
+ switch (attachment->type) {
+ case KFD_MEM_ATT_SHARED:
+ return 0;
+ case KFD_MEM_ATT_USERPTR:
+ return kfd_mem_dmamap_userptr(mem, attachment);
+ default:
+ WARN_ON_ONCE(1);
+ }
+ return -EINVAL;
+}
+
+static void
+kfd_mem_dmaunmap_userptr(struct kgd_mem *mem,
+ struct kfd_mem_attachment *attachment)
+{
+ enum dma_data_direction direction =
+ mem->alloc_flags & KFD_IOC_ALLOC_MEM_FLAGS_WRITABLE ?
+ DMA_BIDIRECTIONAL : DMA_TO_DEVICE;
+ struct ttm_operation_ctx ctx = {.interruptible = false};
+ struct amdgpu_bo *bo = attachment->bo_va->base.bo;
+ struct amdgpu_device *adev = attachment->adev;
+ struct ttm_tt *ttm = bo->tbo.ttm;
+
+ if (unlikely(!ttm->sg))
+ return;
+
+ amdgpu_bo_placement_from_domain(bo, AMDGPU_GEM_DOMAIN_CPU);
+ ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
+
+ dma_unmap_sgtable(adev->dev, ttm->sg, direction, 0);
+ sg_free_table(ttm->sg);
+ ttm->sg = NULL;
+}
+
+static void
+kfd_mem_dmaunmap_attachment(struct kgd_mem *mem,
+ struct kfd_mem_attachment *attachment)
+{
+ switch (attachment->type) {
+ case KFD_MEM_ATT_SHARED:
+ break;
+ case KFD_MEM_ATT_USERPTR:
+ kfd_mem_dmaunmap_userptr(mem, attachment);
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ }
+}
+
/* kfd_mem_attach - Add a BO to a VM
*
* Everything that needs to bo done only once when a BO is first added
* to a VM. It can later be mapped and unmapped many times without
* repeating these steps.
*
+ * 0. Create BO for DMA mapping, if needed
* 1. Allocate and initialize BO VA entry data structure
* 2. Add BO to the VM
* 3. Determine ASIC-specific PTE flags
@@ -486,10 +591,12 @@ static uint64_t get_pte_flags(struct amdgpu_device *adev, struct kgd_mem *mem)
static int kfd_mem_attach(struct amdgpu_device *adev, struct kgd_mem *mem,
struct amdgpu_vm *vm, bool is_aql)
{
+ struct amdgpu_device *bo_adev = amdgpu_ttm_adev(mem->bo->tbo.bdev);
unsigned long bo_size = mem->bo->tbo.base.size;
uint64_t va = mem->va;
struct kfd_mem_attachment *attachment[2] = {NULL, NULL};
struct amdgpu_bo *bo[2] = {NULL, NULL};
+ struct drm_gem_object *gobj;
int i, ret;
if (!va) {
@@ -507,14 +614,36 @@ static int kfd_mem_attach(struct amdgpu_device *adev, struct kgd_mem *mem,
pr_debug("\t add VA 0x%llx - 0x%llx to vm %p\n", va,
va + bo_size, vm);
- /* FIXME: For now all attachments use the same BO. This is
- * incorrect because one BO can only have one DMA mapping
- * for one GPU. We need one BO per GPU, e.g. a DMABuf
- * import with dynamic attachment. This will be addressed
- * one BO-type at a time in subsequent patches.
- */
- bo[i] = mem->bo;
- drm_gem_object_get(&bo[i]->tbo.base);
+ if (adev == bo_adev || (mem->domain == AMDGPU_GEM_DOMAIN_VRAM &&
+ amdgpu_xgmi_same_hive(adev, bo_adev))) {
+ /* Mappings on the local GPU and VRAM mappings in the
+ * local hive share the original BO
+ */
+ attachment[i]->type = KFD_MEM_ATT_SHARED;
+ bo[i] = mem->bo;
+ drm_gem_object_get(&bo[i]->tbo.base);
+ } else if (i > 0) {
+ /* Multiple mappings on the same GPU share the BO */
+ attachment[i]->type = KFD_MEM_ATT_SHARED;
+ bo[i] = bo[0];
+ drm_gem_object_get(&bo[i]->tbo.base);
+ } else if (amdgpu_ttm_tt_get_usermm(mem->bo->tbo.ttm)) {
+ /* Create an SG BO to DMA-map userptrs on other GPUs */
+ attachment[i]->type = KFD_MEM_ATT_USERPTR;
+ ret = amdgpu_gem_object_create(adev, bo_size, 1,
+ AMDGPU_GEM_DOMAIN_CPU,
+ 0, ttm_bo_type_sg,
+ mem->bo->tbo.base.resv,
+ &gobj);
+ if (ret)
+ goto unwind;
+ bo[i] = gem_to_amdgpu_bo(gobj);
+ } else {
+ /* FIXME: Need to DMA-map other BO types */
+ attachment[i]->type = KFD_MEM_ATT_SHARED;
+ bo[i] = mem->bo;
+ drm_gem_object_get(&bo[i]->tbo.base);
+ }
/* Add BO to VM internal data structures */
attachment[i]->bo_va = amdgpu_vm_bo_add(adev, vm, bo[i]);
@@ -557,13 +686,19 @@ static int kfd_mem_attach(struct amdgpu_device *adev, struct kgd_mem *mem,
return ret;
}
-static void kfd_mem_detach(struct kfd_mem_attachment *attachment)
+static void
+kfd_mem_detach(struct kgd_mem *mem, struct kfd_mem_attachment *attachment)
{
struct amdgpu_bo *bo = attachment->bo_va->base.bo;
pr_debug("\t remove VA 0x%llx in entry %p\n",
attachment->va, attachment);
amdgpu_vm_bo_rmv(attachment->adev, attachment->bo_va);
+ /* FIXME: For some reason SG BOs don't get individualized. Do this
+ * now manually. This is probably not the right place to do this.
+ */
+ if (bo != mem->bo)
+ bo->tbo.base.resv = &bo->tbo.base._resv;
drm_gem_object_put(&bo->tbo.base);
list_del(&attachment->list);
kfree(attachment);
@@ -1376,7 +1511,7 @@ int amdgpu_amdkfd_gpuvm_free_memory_of_gpu(
/* Remove from VM internal data structures */
list_for_each_entry_safe(entry, tmp, &mem->attachments, list)
- kfd_mem_detach(entry);
+ kfd_mem_detach(mem, entry);
ret = unreserve_bo_and_vms(&ctx, false, false);
--
2.31.1
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