Commit 2a7a794e authored by Srinivasan Shanmugam's avatar Srinivasan Shanmugam Committed by Alex Deucher
Browse files

drm/amdgpu/ttm: Allocate/Free 4K MMIO_REMAP Singleton 



Add mmio_remap bookkeeping to amdgpu_device and introduce
amdgpu_ttm_mmio_remap_bo_init()/fini() to manage a kernel-owned,
one-page (4K) BO in AMDGPU_GEM_DOMAIN_MMIO_REMAP.

Bookkeeping:
  - adev->rmmio_remap.bo : kernel-owned singleton BO

The BO is allocated during TTM init when a remap bus address is available
(adev->rmmio_remap.bus_addr) and PAGE_SIZE <= AMDGPU_GPU_PAGE_SIZE (4K),
and freed during TTM fini.

v2:
 - Check mmio_remap bus address (adev->rmmio_remap.bus_addr) instead of
   rmmio_base. (Alex)
 - Skip quietly if PAGE_SIZE > AMDGPU_GPU_PAGE_SIZE or no bus address
   (no warn). (Alex)
 - Use `amdgpu_bo_create()` (not *_kernel) - Only with this The object
   is stored in adev->mmio_remap.bo and will later be exposed to
   userspace via a GEM handle. (Christian)

v3:
 - Remove obvious comment before amdgpu_ttm_mmio_remap_bo_fini() call.
   (Alex)

v4:
 - Squash bookkeeping into this patch (Christian)

Suggested-by: default avatarChristian König <christian.koenig@amd.com>
Suggested-by: default avatarAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: default avatarSrinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Reviewed-by: default avatarChristian König <christian.koenig@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 9e46b8bb

drivers/gpu/drm/amd/amdgpu/amdgpu.h

+1 −0
Original line number Diff line number Diff line
@@ -752,6 +752,7 @@ typedef void (*amdgpu_block_wreg_t)(struct amdgpu_device*, uint32_t, uint32_t, u 
struct amdgpu_mmio_remap {

	u32 reg_offset;

	resource_size_t bus_addr;

	struct amdgpu_bo *bo;

};



/* Define the HW IP blocks will be used in driver , add more if necessary */

drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c

+59 −0
Original line number Diff line number Diff line
@@ -1854,6 +1854,59 @@ static void amdgpu_ttm_pools_fini(struct amdgpu_device *adev) 
	adev->mman.ttm_pools = NULL;

}



/**

 * amdgpu_ttm_mmio_remap_bo_init - Allocate the singleton 4K MMIO_REMAP BO

 * @adev: amdgpu device

 *

 * Allocates a one-page (4K) GEM BO in AMDGPU_GEM_DOMAIN_MMIO_REMAP when the

 * hardware exposes a remap base (adev->rmmio_remap.bus_addr) and the host

 * PAGE_SIZE is <= AMDGPU_GPU_PAGE_SIZE (4K). The BO is created as a regular

 * GEM object (amdgpu_bo_create).

 *

 * Return:

 *  * 0 on success or intentional skip (feature not present/unsupported)

 *  * negative errno on allocation failure

 */

static int amdgpu_ttm_mmio_remap_bo_init(struct amdgpu_device *adev)

{

	struct amdgpu_bo_param bp;

	int r;



	/* Skip if HW doesn't expose remap, or if PAGE_SIZE > AMDGPU_GPU_PAGE_SIZE (4K). */

	if (!adev->rmmio_remap.bus_addr || PAGE_SIZE > AMDGPU_GPU_PAGE_SIZE)

		return 0;



	memset(&bp, 0, sizeof(bp));



	/* Create exactly one GEM BO in the MMIO_REMAP domain. */

	bp.type        = ttm_bo_type_device;          /* userspace-mappable GEM */

	bp.size        = AMDGPU_GPU_PAGE_SIZE;        /* 4K */

	bp.byte_align  = AMDGPU_GPU_PAGE_SIZE;

	bp.domain      = AMDGPU_GEM_DOMAIN_MMIO_REMAP;

	bp.flags       = 0;

	bp.resv        = NULL;

	bp.bo_ptr_size = sizeof(struct amdgpu_bo);



	r = amdgpu_bo_create(adev, &bp, &adev->rmmio_remap.bo);

	if (r)

		return r;



	return 0;

}



/**

 * amdgpu_ttm_mmio_remap_bo_fini - Free the singleton MMIO_REMAP BO

 * @adev: amdgpu device

 *

 * Frees the kernel-owned MMIO_REMAP BO if it was allocated by

 * amdgpu_ttm_mmio_remap_bo_init().

 */

static void amdgpu_ttm_mmio_remap_bo_fini(struct amdgpu_device *adev)

{

	amdgpu_bo_unref(&adev->rmmio_remap.bo);

	adev->rmmio_remap.bo = NULL;

}



/*

 * amdgpu_ttm_init - Init the memory management (ttm) as well as various

 * gtt/vram related fields.
@@ -2028,6 +2081,11 @@ int amdgpu_ttm_init(struct amdgpu_device *adev) 
		return r;

	}



	/* Allocate the singleton MMIO_REMAP BO (4K) if supported */

	r = amdgpu_ttm_mmio_remap_bo_init(adev);

	if (r)

		return r;



	/* Initialize preemptible memory pool */

	r = amdgpu_preempt_mgr_init(adev);

	if (r) {
@@ -2091,6 +2149,7 @@ void amdgpu_ttm_fini(struct amdgpu_device *adev) 
	amdgpu_bo_free_kernel(&adev->mman.sdma_access_bo, NULL,

					&adev->mman.sdma_access_ptr);



	amdgpu_ttm_mmio_remap_bo_fini(adev);

	amdgpu_ttm_fw_reserve_vram_fini(adev);

	amdgpu_ttm_drv_reserve_vram_fini(adev);