NAK, please use the existing functionality for that.
Using amdgpu_bo_do_create() with domain=0 will just create the amdgpu_bo
structure without allocating any backing memory.
This BO can then pinned to the desired VRAM location using amdgpu_bo_pin().
Regards,
Christian.
Am 28.09.2017 um 10:36 schrieb Horace Chen:
> Add two function to create and free bo at the specified position
> on the VRAM.
>
> Add a new parameter to amdgpu_bo_do_create to tell the start
> address of the special bo. If the start address is located in
> the GPU MC address space, the placement will be set to the exact
> place according to the size and start address. Otherwise the start
> address will be ingored.
>
> Signed-off-by: Horace Chen <horace.chen at amd.com>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 129 ++++++++++++++++++++++++++++-
> drivers/gpu/drm/amd/amdgpu/amdgpu_object.h | 6 ++
> 2 files changed, 133 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> index 6982bae..0695160 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> @@ -284,6 +284,7 @@ void amdgpu_bo_free_kernel(struct amdgpu_bo **bo, u64 *gpu_addr,
> }
>
> static int amdgpu_bo_do_create(struct amdgpu_device *adev,
> + u64 start_addr,
> unsigned long size, int byte_align,
> bool kernel, u32 domain, u64 flags,
> struct sg_table *sg,
> @@ -297,9 +298,12 @@ static int amdgpu_bo_do_create(struct amdgpu_device *adev,
> u64 initial_bytes_moved, bytes_moved;
> size_t acc_size;
> int r;
> + int i;
> + bool vram_restricted = false;
>
> page_align = roundup(byte_align, PAGE_SIZE) >> PAGE_SHIFT;
> size = ALIGN(size, PAGE_SIZE);
> + start_addr = ALIGN(start_addr, PAGE_SIZE);
>
> if (kernel) {
> type = ttm_bo_type_kernel;
> @@ -366,6 +370,32 @@ static int amdgpu_bo_do_create(struct amdgpu_device *adev,
> bo->tbo.bdev = &adev->mman.bdev;
> amdgpu_ttm_placement_from_domain(bo, domain);
>
> + /*
> + * if domain is VRAM && start_addr in vram address space,
> + * set the place to the specified place
> + */
> + if ((domain == AMDGPU_GEM_DOMAIN_VRAM) &&
> + start_addr >= adev->mc.vram_start &&
> + (start_addr + size) < adev->mc.vram_end) {
> + start_addr -= adev->mc.vram_start;
> + vram_restricted = true;
> + } else if ((domain == AMDGPU_GEM_DOMAIN_GTT) &&
> + start_addr >= adev->mc.gart_start &&
> + (start_addr + size) < adev->mc.gart_end) {
> + /* if in gart address space */
> + start_addr -= adev->mc.gart_start;
> + vram_restricted = true;
> + }
> +
> + if (vram_restricted) {
> + for (i = 0; i < bo->placement.num_placement; ++i) {
> + bo->placements[i].fpfn =
> + start_addr >> PAGE_SHIFT;
> + bo->placements[i].lpfn =
> + (start_addr + size) >> PAGE_SHIFT;
> + }
> + }
> +
> initial_bytes_moved = atomic64_read(&adev->num_bytes_moved);
> /* Kernel allocation are uninterruptible */
> r = ttm_bo_init_reserved(&adev->mman.bdev, &bo->tbo, size, type,
> @@ -418,6 +448,101 @@ static int amdgpu_bo_do_create(struct amdgpu_device *adev,
> return r;
> }
>
> +/**
> + * amdgpu_bo_create_vram_restricted_kernel -
> + * create BO at the specified place on the VRAM.
> + *
> + * @adev: amdgpu device object
> + * @offset: start offset of the new BO
> + * @size: size for the new BO
> + * @byte_align: alignment for the new BO
> + * @flags: addition flags for the BO
> + * @bo_ptr: resulting BO
> + * @gpu_addr: GPU addr of the pinned BO
> + * @cpu_addr: optional CPU address mapping
> + *
> + * Allocates and pins a BO at the specified place on the VRAM.
> + *
> + * Returns 0 on success, negative error code otherwise.
> + */
> +int amdgpu_bo_create_vram_restricted_kernel(struct amdgpu_device *adev,
> + u64 offset, unsigned long size, int byte_align,
> + u64 flags, struct amdgpu_bo **bo_ptr,
> + u64 *gpu_addr, void **cpu_addr)
> +{
> + int r;
> + u64 start_addr = offset + adev->mc.vram_start;
> + /* specified memory must be in contiguous*/
> + flags |= AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS;
> +
> + r = amdgpu_bo_do_create(adev, start_addr, size, byte_align, true,
> + AMDGPU_GEM_DOMAIN_VRAM, flags, NULL, NULL, 0, bo_ptr);
> + if (r)
> + return r;
> +
> + r = amdgpu_bo_reserve(*bo_ptr, false);
> + if (r)
> + goto error_reserve;
> + r = amdgpu_bo_pin_restricted(*bo_ptr,
> + AMDGPU_GEM_DOMAIN_VRAM, offset, (offset + size),
> + gpu_addr);
> + if (r)
> + goto error_pin;
> + if (cpu_addr) {
> + r = amdgpu_bo_kmap(*bo_ptr,
> + cpu_addr);
> + if (r)
> + goto error_kmap;
> + }
> +
> + amdgpu_bo_unreserve(*bo_ptr);
> +
> + return r;
> +error_kmap:
> + amdgpu_bo_unpin(*bo_ptr);
> +error_pin:
> + amdgpu_bo_unreserve(*bo_ptr);
> +error_reserve:
> + amdgpu_bo_unref(bo_ptr);
> + if (cpu_addr)
> + *cpu_addr = NULL;
> + if (gpu_addr)
> + *gpu_addr = 0;
> + return r;
> +}
> +
> +/**
> + * amdgpu_bo_free_vram_restricted_kernel - free BO for restricted vram
> + *
> + * @bo: amdgpu BO to free
> + * @gpu_addr : gpu address
> + * @cpu_addr : cpu address if mapped
> + *
> + * unmaps and unpin a BO which created by
> + * amdgpu_bo_create_vram_restricted_kernel.
> + */
> +void amdgpu_bo_free_vram_restricted_kernel(struct amdgpu_bo **bo, u64 *gpu_addr,
> + void **cpu_addr)
> +{
> + if (*bo == NULL)
> + return;
> +
> + if (likely(amdgpu_bo_reserve(*bo, true) == 0)) {
> + if (cpu_addr)
> + amdgpu_bo_kunmap(*bo);
> + amdgpu_bo_unpin(*bo);
> + amdgpu_bo_unreserve(*bo);
> + }
> + amdgpu_bo_unref(bo);
> +
> + if (gpu_addr)
> + *gpu_addr = 0;
> +
> + if (cpu_addr)
> + *cpu_addr = NULL;
> +}
> +
> +
> static int amdgpu_bo_create_shadow(struct amdgpu_device *adev,
> unsigned long size, int byte_align,
> struct amdgpu_bo *bo)
> @@ -427,7 +552,7 @@ static int amdgpu_bo_create_shadow(struct amdgpu_device *adev,
> if (bo->shadow)
> return 0;
>
> - r = amdgpu_bo_do_create(adev, size, byte_align, true,
> + r = amdgpu_bo_do_create(adev, 0, size, byte_align, true,
> AMDGPU_GEM_DOMAIN_GTT,
> AMDGPU_GEM_CREATE_CPU_GTT_USWC |
> AMDGPU_GEM_CREATE_SHADOW,
> @@ -457,7 +582,7 @@ int amdgpu_bo_create(struct amdgpu_device *adev,
> uint64_t parent_flags = flags & ~AMDGPU_GEM_CREATE_SHADOW;
> int r;
>
> - r = amdgpu_bo_do_create(adev, size, byte_align, kernel, domain,
> + r = amdgpu_bo_do_create(adev, 0, size, byte_align, kernel, domain,
> parent_flags, sg, resv, init_value, bo_ptr);
> if (r)
> return r;
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
> index 39b6bf6..0f34ba77 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
> @@ -205,6 +205,12 @@ int amdgpu_bo_create_kernel(struct amdgpu_device *adev,
> u64 *gpu_addr, void **cpu_addr);
> void amdgpu_bo_free_kernel(struct amdgpu_bo **bo, u64 *gpu_addr,
> void **cpu_addr);
> +int amdgpu_bo_create_vram_restricted_kernel(struct amdgpu_device *adev,
> + u64 offset, unsigned long size, int byte_align,
> + u64 flags, struct amdgpu_bo **bo_ptr,
> + u64 *gpu_addr, void **cpu_addr);
> +void amdgpu_bo_free_vram_restricted_kernel(struct amdgpu_bo **bo, u64 *gpu_addr,
> + void **cpu_addr);
> int amdgpu_bo_kmap(struct amdgpu_bo *bo, void **ptr);
> void *amdgpu_bo_kptr(struct amdgpu_bo *bo);
> void amdgpu_bo_kunmap(struct amdgpu_bo *bo);
