AMD General

reserve_mem_limit() computes available VRAM as

        vram_size - reserved - vram_pin_size - kfd.vram_used

However, kfd.vram_used already includes BOs that are later pinned.
Pinning does not consume extra VRAM. Subtracting vram_pin_size counts those 
bytes twice and causes fake-OOM while VRAM is still free.

New design reuses get_available_memory() for getting available VRAM in 
reserve_mem_limit(). Move ALIGN_DOWN to the ioctl so the userspace ABI is 
unchanged.

kfd.vram_pinned is only updated in gpuvm_pin_bo(). dma-buf pin calls 
amdgpu_bo_pin() only, so the counter stays zero.
Update it from amdgpu_bo_pin() through a KFD helper, on first pin and last 
unpin, matching vram_pin_size.

Signed-off-by: Zhen Han <[email protected]>
---
v4:
- use get_available_memory() in reserve_mem_limit()
- move ALIGN_DOWN from get_available_memory() to the ioctl
- drop v3 extra call in amdgpu_dma_buf.c
- update kfd.vram_pinned from amdgpu_bo_pin() via a KFD helper

v3:
- update kfd.vram_pinned from dma-buf pin/vmap and gpuvm_pin_bo
  on first pin / last unpin in amdgpu_dma_buf.c

v2:
- keep vram_pin_size; add kfd.vram_pinned in reserve_mem_limit (Mukul Joshi)
- leave get_available_memory unchanged
- drop former 2/2 pin/unpin changes in amdgpu_object.c

 drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h    | 18 +++++
 .../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c  | 81 +++++++++++--------
 drivers/gpu/drm/amd/amdgpu/amdgpu_object.c    |  2 +
 drivers/gpu/drm/amd/amdkfd/kfd_chardev.c      | 12 ++-
 4 files changed, 76 insertions(+), 37 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
index 4541542a28df..ff6aab8a8657 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
@@ -42,6 +42,12 @@

 extern uint64_t amdgpu_amdkfd_total_mem_size;

+/*
+ * Align VRAM availability to 2MB to avoid fragmentation caused by 4K
+ * allocations in the tail 2MB BO chunk.
+ */
+#define VRAM_AVAILABLITY_ALIGN (1 << 21)
+
 enum TLB_FLUSH_TYPE {
        TLB_FLUSH_LEGACY = 0,
        TLB_FLUSH_LIGHTWEIGHT,
@@ -456,6 +462,8 @@ void amdgpu_amdkfd_gpuvm_destroy_cb(struct amdgpu_device 
*adev,
  * Allows KFD to release its resources associated with the GEM object.
  */
 void amdgpu_amdkfd_release_notify(struct amdgpu_bo *bo);
+void amdgpu_amdkfd_account_vram_pin(struct amdgpu_bo *bo); void
+amdgpu_amdkfd_account_vram_unpin(struct amdgpu_bo *bo);
 void amdgpu_amdkfd_reserve_system_mem(uint64_t size);  #else  static inline @@ 
-473,6 +481,16 @@ static inline  void amdgpu_amdkfd_release_notify(struct 
amdgpu_bo *bo)  {  }
+
+static inline
+void amdgpu_amdkfd_account_vram_pin(struct amdgpu_bo *bo) { }
+
+static inline
+void amdgpu_amdkfd_account_vram_unpin(struct amdgpu_bo *bo) { }
 #endif

 void amdgpu_amdkfd_rlc_spm_cntl(struct amdgpu_device *adev, int xcc_id, bool 
cntl);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
index 89958d0f7e59..eb894a6fe5ef 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
@@ -48,12 +48,6 @@
 #define AMDGPU_USERPTR_RESTORE_DELAY_MS 1
 #define AMDGPU_RESERVE_MEM_LIMIT                       (3UL << 29)

-/*
- * Align VRAM availability to 2MB to avoid fragmentation caused by 4K 
allocations in the tail 2MB
- * BO chunk
- */
-#define VRAM_AVAILABLITY_ALIGN (1 << 21)
-
 /* Impose limit on how much memory KFD can use */
 static struct {
        uint64_t max_system_mem_limit;
@@ -75,6 +69,8 @@ static const char * const domain_bit_to_string[] = {
 #define domain_string(domain) domain_bit_to_string[ffs(domain)-1]

 static void amdgpu_amdkfd_restore_userptr_worker(struct work_struct *work);
+static size_t __get_available_memory(struct amdgpu_device *adev,
+                                    uint8_t xcp_id);

 static bool kfd_mem_is_attached(struct amdgpu_vm *avm,
                struct kgd_mem *mem)
@@ -171,13 +167,8 @@ void amdgpu_amdkfd_reserve_system_mem(uint64_t size)
 int amdgpu_amdkfd_reserve_mem_limit(struct amdgpu_device *adev,
                uint64_t size, u32 alloc_flag, int8_t xcp_id)
 {
-       uint64_t reserved_for_pt =
-               ESTIMATE_PT_SIZE(amdgpu_amdkfd_total_mem_size);
-       struct amdgpu_ras *con = amdgpu_ras_get_context(adev);
-       uint64_t reserved_for_ras = (con ? con->reserved_pages_in_bytes : 0);
        size_t system_mem_needed, ttm_mem_needed, vram_needed;
        int ret = 0;
-       uint64_t vram_size = 0;

        system_mem_needed = 0;
        ttm_mem_needed = 0;
@@ -198,7 +189,6 @@ int amdgpu_amdkfd_reserve_mem_limit(struct amdgpu_device 
*adev,
                if (WARN_ONCE(xcp_id < 0, "invalid XCP ID %d", xcp_id))
                        return -EINVAL;

-               vram_size = KFD_XCP_MEMORY_SIZE(adev, xcp_id);
                if (adev->apu_prefer_gtt) {
                        system_mem_needed = size;
                        ttm_mem_needed = size;
@@ -234,14 +224,10 @@ int amdgpu_amdkfd_reserve_mem_limit(struct amdgpu_device 
*adev,
         * VRAM check since ttm_mem_limit check already cover this allocation
         */

-       if (adev && xcp_id >= 0 && (!adev->apu_prefer_gtt || 
adev->gmc.is_app_apu)) {
-               uint64_t vram_available =
-                       vram_size - reserved_for_pt - reserved_for_ras -
-                       atomic64_read(&adev->vram_pin_size);
-               if (adev->kfd.vram_used[xcp_id] + vram_needed > vram_available) 
{
-                       ret = -ENOMEM;
-                       goto release;
-               }
+       if (adev && xcp_id >= 0 && (!adev->apu_prefer_gtt || 
adev->gmc.is_app_apu) &&
+           vram_needed > __get_available_memory(adev, xcp_id)) {
+               ret = -ENOMEM;
+               goto release;
        }

        /* Update memory accounting by decreasing available system
@@ -320,6 +306,28 @@ void amdgpu_amdkfd_release_notify(struct amdgpu_bo *bo)
        kfree(bo->kfd_bo);
 }

+void amdgpu_amdkfd_account_vram_pin(struct amdgpu_bo *bo)
+{
+       if (!bo->kfd_bo || !bo->tbo.resource)
+               return;
+       if (bo->tbo.resource->mem_type != TTM_PL_VRAM)
+               return;
+
+       atomic64_add(amdgpu_bo_size(bo),
+                    &amdgpu_ttm_adev(bo->tbo.bdev)->kfd.vram_pinned);
+}
+
+void amdgpu_amdkfd_account_vram_unpin(struct amdgpu_bo *bo)
+{
+       if (!bo->kfd_bo || !bo->tbo.resource)
+               return;
+       if (bo->tbo.resource->mem_type != TTM_PL_VRAM)
+               return;
+
+       atomic64_sub(amdgpu_bo_size(bo),
+                    &amdgpu_ttm_adev(bo->tbo.bdev)->kfd.vram_pinned);
+}
+
 /**
  * create_dmamap_sg_bo() - Creates a amdgpu_bo object to reflect information
  * about USERPTR or DOOREBELL or MMIO BO.
@@ -1626,10 +1634,6 @@ int amdgpu_amdkfd_gpuvm_pin_bo(struct amdgpu_bo *bo, u32 
domain)

        amdgpu_bo_sync_wait(bo, AMDGPU_FENCE_OWNER_KFD, false);

-       if (!ret && bo->tbo.resource->mem_type == TTM_PL_VRAM)
-                atomic64_add(amdgpu_bo_size(bo),
-                        &amdgpu_ttm_adev(bo->tbo.bdev)->kfd.vram_pinned);
-
 out:
        amdgpu_bo_unreserve(bo);
        return ret;
@@ -1653,10 +1657,6 @@ void amdgpu_amdkfd_gpuvm_unpin_bo(struct amdgpu_bo *bo)

        amdgpu_bo_unpin(bo);

-       if (bo->tbo.resource->mem_type == TTM_PL_VRAM)
-               atomic64_sub(amdgpu_bo_size(bo),
-                       &amdgpu_ttm_adev(bo->tbo.bdev)->kfd.vram_pinned);
-
        amdgpu_bo_unreserve(bo);
 }

@@ -1760,8 +1760,9 @@ int amdgpu_amdkfd_criu_resume(void *p)
        return ret;
 }

-size_t amdgpu_amdkfd_get_available_memory(struct amdgpu_device *adev,
-                                         uint8_t xcp_id)
+/* Caller must hold kfd_mem_limit.mem_limit_lock. */
+static size_t __get_available_memory(struct amdgpu_device *adev,
+                                    uint8_t xcp_id)
 {
        uint64_t reserved_for_pt =
                ESTIMATE_PT_SIZE(amdgpu_amdkfd_total_mem_size);
@@ -1770,7 +1771,8 @@ size_t amdgpu_amdkfd_get_available_memory(struct 
amdgpu_device *adev,
        ssize_t available;
        uint64_t vram_available, system_mem_available, ttm_mem_available;

-       spin_lock(&kfd_mem_limit.mem_limit_lock);
+       lockdep_assert_held(&kfd_mem_limit.mem_limit_lock);
+
        if (adev->apu_prefer_gtt && !adev->gmc.is_app_apu)
                vram_available = KFD_XCP_MEMORY_SIZE(adev, xcp_id)
                        - adev->kfd.vram_used_aligned[xcp_id];
@@ -1793,19 +1795,28 @@ size_t amdgpu_amdkfd_get_available_memory(struct 
amdgpu_device *adev,

                available = min3(system_mem_available, ttm_mem_available,
                                 vram_available);
-               available = ALIGN_DOWN(available, PAGE_SIZE);
        } else {
-               available = ALIGN_DOWN(vram_available, VRAM_AVAILABLITY_ALIGN);
+               available = vram_available;
        }

-       spin_unlock(&kfd_mem_limit.mem_limit_lock);
-
        if (available < 0)
                available = 0;

        return available;
 }

+size_t amdgpu_amdkfd_get_available_memory(struct amdgpu_device *adev,
+                                         uint8_t xcp_id)
+{
+       size_t available;
+
+       spin_lock(&kfd_mem_limit.mem_limit_lock);
+       available = __get_available_memory(adev, xcp_id);
+       spin_unlock(&kfd_mem_limit.mem_limit_lock);
+
+       return available;
+}
+
 int amdgpu_amdkfd_gpuvm_alloc_memory_of_gpu(
                struct amdgpu_device *adev, uint64_t va, uint64_t size,
                void *drm_priv, struct kgd_mem **mem,
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
index b66a0eeda788..233e94db930e 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
@@ -1004,6 +1004,7 @@ int amdgpu_bo_pin(struct amdgpu_bo *bo, u32 domain)
                atomic64_add(amdgpu_bo_size(bo), &adev->vram_pin_size);
                atomic64_add(amdgpu_vram_mgr_bo_visible_size(bo),
                             &adev->visible_pin_size);
+               amdgpu_amdkfd_account_vram_pin(bo);
        } else if (bo->tbo.resource->mem_type == TTM_PL_TT) {
                atomic64_add(amdgpu_bo_size(bo), &adev->gart_pin_size);
        }
@@ -1039,6 +1040,7 @@ void amdgpu_bo_unpin(struct amdgpu_bo *bo)
                atomic64_sub(amdgpu_bo_size(bo), &adev->vram_pin_size);
                atomic64_sub(amdgpu_vram_mgr_bo_visible_size(bo),
                             &adev->visible_pin_size);
+               amdgpu_amdkfd_account_vram_unpin(bo);
        } else if (bo->tbo.resource->mem_type == TTM_PL_TT) {
                atomic64_sub(amdgpu_bo_size(bo), &adev->gart_pin_size);
        }
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c 
b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
index 9751a912177c..1baa5d95f71a 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
@@ -1073,11 +1073,19 @@ static int kfd_ioctl_get_available_memory(struct file 
*filep,
 {
        struct kfd_ioctl_get_available_memory_args *args = data;
        struct kfd_process_device *pdd = kfd_lock_pdd_by_id(p, args->gpu_id);
+       struct amdgpu_device *adev;
+       size_t available;

        if (!pdd)
                return -EINVAL;
-       args->available = amdgpu_amdkfd_get_available_memory(pdd->dev->adev,
-                                                       pdd->dev->node_id);
+
+       adev = pdd->dev->adev;
+       available = amdgpu_amdkfd_get_available_memory(adev, pdd->dev->node_id);
+       if (adev->apu_prefer_gtt)
+               args->available = ALIGN_DOWN(available, PAGE_SIZE);
+       else
+               args->available = ALIGN_DOWN(available, VRAM_AVAILABLITY_ALIGN);
+
        kfd_unlock_pdd(pdd);
        return 0;
 }
--
2.43.7

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