[PATCH] drm/amd/amdgpu: Code comments for the amdgpu_ttm.c driver. (v2)
Christian König
ckoenig.leichtzumerken at gmail.com
Fri May 18 09:52:50 UTC 2018
Am 17.05.2018 um 17:34 schrieb Alex Deucher:
> On Tue, May 15, 2018 at 10:02 AM, Tom St Denis <tom.stdenis at amd.com> wrote:
>> NFC just comments.
>>
>> (v2): Updated based on feedback from Alex Deucher.
>>
>> Signed-off-by: Tom St Denis <tom.stdenis at amd.com>
> Reviewed-by: Alex Deucher <alexander.deucher at amd.com>
Just one comment "Pin pages of memory pointed to..." better write "Grab
a reference to the memory pointed to...".
get_user_pages() does not pin anything! I've heard that misconception so
many times now that I can't remember how often we had to explain it and
we should definitely not leak it into the documentation.
With that fixed the patch is Reviewed-by: Christian König
<christian.koenig at amd.com>.
Regards,
Christian.
>
>> ---
>> drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 347 +++++++++++++++++++++++++++++++-
>> 1 file changed, 340 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>> index dfd22db13fb1..2eaaa1fb7b59 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>> @@ -63,16 +63,44 @@ static void amdgpu_ttm_debugfs_fini(struct amdgpu_device *adev);
>> /*
>> * Global memory.
>> */
>> +
>> +/**
>> + * amdgpu_ttm_mem_global_init - Initialize and acquire reference to
>> + * memory object
>> + *
>> + * @ref: Object for initialization.
>> + *
>> + * This is called by drm_global_item_ref() when an object is being
>> + * initialized.
>> + */
>> static int amdgpu_ttm_mem_global_init(struct drm_global_reference *ref)
>> {
>> return ttm_mem_global_init(ref->object);
>> }
>>
>> +/**
>> + * amdgpu_ttm_mem_global_release - Drop reference to a memory object
>> + *
>> + * @ref: Object being removed
>> + *
>> + * This is called by drm_global_item_unref() when an object is being
>> + * released.
>> + */
>> static void amdgpu_ttm_mem_global_release(struct drm_global_reference *ref)
>> {
>> ttm_mem_global_release(ref->object);
>> }
>>
>> +/**
>> + * amdgpu_ttm_global_init - Initialize global TTM memory reference
>> + * structures.
>> + *
>> + * @adev: AMDGPU device for which the global structures need to be
>> + * registered.
>> + *
>> + * This is called as part of the AMDGPU ttm init from amdgpu_ttm_init()
>> + * during bring up.
>> + */
>> static int amdgpu_ttm_global_init(struct amdgpu_device *adev)
>> {
>> struct drm_global_reference *global_ref;
>> @@ -80,7 +108,9 @@ static int amdgpu_ttm_global_init(struct amdgpu_device *adev)
>> struct drm_sched_rq *rq;
>> int r;
>>
>> + /* ensure reference is false in case init fails */
>> adev->mman.mem_global_referenced = false;
>> +
>> global_ref = &adev->mman.mem_global_ref;
>> global_ref->global_type = DRM_GLOBAL_TTM_MEM;
>> global_ref->size = sizeof(struct ttm_mem_global);
>> @@ -146,6 +176,18 @@ static int amdgpu_invalidate_caches(struct ttm_bo_device *bdev, uint32_t flags)
>> return 0;
>> }
>>
>> +/**
>> + * amdgpu_init_mem_type - Initialize a memory manager for a specific
>> + * type of memory request.
>> + *
>> + * @bdev: The TTM BO device object (contains a reference to
>> + * amdgpu_device)
>> + * @type: The type of memory requested
>> + * @man:
>> + *
>> + * This is called by ttm_bo_init_mm() when a buffer object is being
>> + * initialized.
>> + */
>> static int amdgpu_init_mem_type(struct ttm_bo_device *bdev, uint32_t type,
>> struct ttm_mem_type_manager *man)
>> {
>> @@ -161,6 +203,7 @@ static int amdgpu_init_mem_type(struct ttm_bo_device *bdev, uint32_t type,
>> man->default_caching = TTM_PL_FLAG_CACHED;
>> break;
>> case TTM_PL_TT:
>> + /* GTT memory */
>> man->func = &amdgpu_gtt_mgr_func;
>> man->gpu_offset = adev->gmc.gart_start;
>> man->available_caching = TTM_PL_MASK_CACHING;
>> @@ -193,6 +236,14 @@ static int amdgpu_init_mem_type(struct ttm_bo_device *bdev, uint32_t type,
>> return 0;
>> }
>>
>> +/**
>> + * amdgpu_evict_flags - Compute placement flags
>> + *
>> + * @bo: The buffer object to evict
>> + * @placement: Possible destination(s) for evicted BO
>> + *
>> + * Fill in placement data when ttm_bo_evict() is called
>> + */
>> static void amdgpu_evict_flags(struct ttm_buffer_object *bo,
>> struct ttm_placement *placement)
>> {
>> @@ -204,12 +255,14 @@ static void amdgpu_evict_flags(struct ttm_buffer_object *bo,
>> .flags = TTM_PL_MASK_CACHING | TTM_PL_FLAG_SYSTEM
>> };
>>
>> + /* Don't handle scatter gather BOs */
>> if (bo->type == ttm_bo_type_sg) {
>> placement->num_placement = 0;
>> placement->num_busy_placement = 0;
>> return;
>> }
>>
>> + /* Object isn't an AMDGPU object so ignore */
>> if (!amdgpu_ttm_bo_is_amdgpu_bo(bo)) {
>> placement->placement = &placements;
>> placement->busy_placement = &placements;
>> @@ -217,10 +270,12 @@ static void amdgpu_evict_flags(struct ttm_buffer_object *bo,
>> placement->num_busy_placement = 1;
>> return;
>> }
>> +
>> abo = ttm_to_amdgpu_bo(bo);
>> switch (bo->mem.mem_type) {
>> case TTM_PL_VRAM:
>> if (!adev->mman.buffer_funcs_enabled) {
>> + /* Move to system memory */
>> amdgpu_ttm_placement_from_domain(abo, AMDGPU_GEM_DOMAIN_CPU);
>> } else if (adev->gmc.visible_vram_size < adev->gmc.real_vram_size &&
>> !(abo->flags & AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED) &&
>> @@ -238,6 +293,7 @@ static void amdgpu_evict_flags(struct ttm_buffer_object *bo,
>> abo->placement.busy_placement = &abo->placements[1];
>> abo->placement.num_busy_placement = 1;
>> } else {
>> + /* Move to GTT memory */
>> amdgpu_ttm_placement_from_domain(abo, AMDGPU_GEM_DOMAIN_GTT);
>> }
>> break;
>> @@ -248,6 +304,15 @@ static void amdgpu_evict_flags(struct ttm_buffer_object *bo,
>> *placement = abo->placement;
>> }
>>
>> +/**
>> + * amdgpu_verify_access - Verify access for a mmap call
>> + *
>> + * @bo: The buffer object to map
>> + * @filp: The file pointer from the process performing the mmap
>> + *
>> + * This is called by ttm_bo_mmap() to verify whether a process
>> + * has the right to mmap a BO to their process space.
>> + */
>> static int amdgpu_verify_access(struct ttm_buffer_object *bo, struct file *filp)
>> {
>> struct amdgpu_bo *abo = ttm_to_amdgpu_bo(bo);
>> @@ -265,6 +330,15 @@ static int amdgpu_verify_access(struct ttm_buffer_object *bo, struct file *filp)
>> filp->private_data);
>> }
>>
>> +/**
>> + * amdgpu_move_null - Register memory for a buffer object
>> + *
>> + * @bo: The bo to assign the memory to
>> + * @new_mem: The memory to be assigned.
>> + *
>> + * Assign the memory from new_mem to the memory of the buffer object
>> + * bo.
>> + */
>> static void amdgpu_move_null(struct ttm_buffer_object *bo,
>> struct ttm_mem_reg *new_mem)
>> {
>> @@ -275,6 +349,10 @@ static void amdgpu_move_null(struct ttm_buffer_object *bo,
>> new_mem->mm_node = NULL;
>> }
>>
>> +/**
>> + * amdgpu_mm_node_addr - Compute the GPU relative offset of a GTT
>> + * buffer.
>> + */
>> static uint64_t amdgpu_mm_node_addr(struct ttm_buffer_object *bo,
>> struct drm_mm_node *mm_node,
>> struct ttm_mem_reg *mem)
>> @@ -289,9 +367,10 @@ static uint64_t amdgpu_mm_node_addr(struct ttm_buffer_object *bo,
>> }
>>
>> /**
>> - * amdgpu_find_mm_node - Helper function finds the drm_mm_node
>> - * corresponding to @offset. It also modifies the offset to be
>> - * within the drm_mm_node returned
>> + * amdgpu_find_mm_node - Helper function finds the drm_mm_node
>> + * corresponding to @offset. It also modifies
>> + * the offset to be within the drm_mm_node
>> + * returned
>> */
>> static struct drm_mm_node *amdgpu_find_mm_node(struct ttm_mem_reg *mem,
>> unsigned long *offset)
>> @@ -430,7 +509,12 @@ int amdgpu_ttm_copy_mem_to_mem(struct amdgpu_device *adev,
>> return r;
>> }
>>
>> -
>> +/**
>> + * amdgpu_move_blit - Copy an entire buffer to another buffer
>> + *
>> + * This is a helper called by amdgpu_bo_move() and
>> + * amdgpu_move_vram_ram() to help move buffers to and from VRAM.
>> + */
>> static int amdgpu_move_blit(struct ttm_buffer_object *bo,
>> bool evict, bool no_wait_gpu,
>> struct ttm_mem_reg *new_mem,
>> @@ -465,6 +549,11 @@ static int amdgpu_move_blit(struct ttm_buffer_object *bo,
>> return r;
>> }
>>
>> +/**
>> + * amdgpu_move_vram_ram - Copy VRAM buffer to RAM buffer
>> + *
>> + * Called by amdgpu_bo_move().
>> + */
>> static int amdgpu_move_vram_ram(struct ttm_buffer_object *bo, bool evict,
>> struct ttm_operation_ctx *ctx,
>> struct ttm_mem_reg *new_mem)
>> @@ -477,6 +566,8 @@ static int amdgpu_move_vram_ram(struct ttm_buffer_object *bo, bool evict,
>> int r;
>>
>> adev = amdgpu_ttm_adev(bo->bdev);
>> +
>> + /* create space/pages for new_mem in GTT space */
>> tmp_mem = *new_mem;
>> tmp_mem.mm_node = NULL;
>> placement.num_placement = 1;
>> @@ -491,25 +582,36 @@ static int amdgpu_move_vram_ram(struct ttm_buffer_object *bo, bool evict,
>> return r;
>> }
>>
>> + /* set caching flags */
>> r = ttm_tt_set_placement_caching(bo->ttm, tmp_mem.placement);
>> if (unlikely(r)) {
>> goto out_cleanup;
>> }
>>
>> + /* Bind the memory to the GTT space */
>> r = ttm_tt_bind(bo->ttm, &tmp_mem, ctx);
>> if (unlikely(r)) {
>> goto out_cleanup;
>> }
>> +
>> + /* blit VRAM to GTT */
>> r = amdgpu_move_blit(bo, true, ctx->no_wait_gpu, &tmp_mem, old_mem);
>> if (unlikely(r)) {
>> goto out_cleanup;
>> }
>> +
>> + /* move BO (in tmp_mem) to new_mem */
>> r = ttm_bo_move_ttm(bo, ctx, new_mem);
>> out_cleanup:
>> ttm_bo_mem_put(bo, &tmp_mem);
>> return r;
>> }
>>
>> +/**
>> + * amdgpu_move_ram_vram - Copy buffer from RAM to VRAM
>> + *
>> + * Called by amdgpu_bo_move().
>> + */
>> static int amdgpu_move_ram_vram(struct ttm_buffer_object *bo, bool evict,
>> struct ttm_operation_ctx *ctx,
>> struct ttm_mem_reg *new_mem)
>> @@ -522,6 +624,8 @@ static int amdgpu_move_ram_vram(struct ttm_buffer_object *bo, bool evict,
>> int r;
>>
>> adev = amdgpu_ttm_adev(bo->bdev);
>> +
>> + /* make space in GTT for old_mem buffer */
>> tmp_mem = *new_mem;
>> tmp_mem.mm_node = NULL;
>> placement.num_placement = 1;
>> @@ -535,10 +639,14 @@ static int amdgpu_move_ram_vram(struct ttm_buffer_object *bo, bool evict,
>> if (unlikely(r)) {
>> return r;
>> }
>> +
>> + /* move/bind old memory to GTT space */
>> r = ttm_bo_move_ttm(bo, ctx, &tmp_mem);
>> if (unlikely(r)) {
>> goto out_cleanup;
>> }
>> +
>> + /* copy to VRAM */
>> r = amdgpu_move_blit(bo, true, ctx->no_wait_gpu, new_mem, old_mem);
>> if (unlikely(r)) {
>> goto out_cleanup;
>> @@ -548,6 +656,11 @@ static int amdgpu_move_ram_vram(struct ttm_buffer_object *bo, bool evict,
>> return r;
>> }
>>
>> +/**
>> + * amdgpu_bo_move - Move a buffer object to a new memory location
>> + *
>> + * Called by ttm_bo_handle_move_mem()
>> + */
>> static int amdgpu_bo_move(struct ttm_buffer_object *bo, bool evict,
>> struct ttm_operation_ctx *ctx,
>> struct ttm_mem_reg *new_mem)
>> @@ -613,6 +726,11 @@ static int amdgpu_bo_move(struct ttm_buffer_object *bo, bool evict,
>> return 0;
>> }
>>
>> +/**
>> + * amdgpu_ttm_io_mem_reserve - Reserve a block of memory during a fault
>> + *
>> + * Called by ttm_mem_io_reserve() ultimately via ttm_bo_vm_fault()
>> + */
>> static int amdgpu_ttm_io_mem_reserve(struct ttm_bo_device *bdev, struct ttm_mem_reg *mem)
>> {
>> struct ttm_mem_type_manager *man = &bdev->man[mem->mem_type];
>> @@ -690,6 +808,14 @@ struct amdgpu_ttm_tt {
>> uint32_t last_set_pages;
>> };
>>
>> +/**
>> + * amdgpu_ttm_tt_get_user_pages - Pin pages of memory pointed to
>> + * by a USERPTR pointer to memory
>> + *
>> + * Called by amdgpu_gem_userptr_ioctl() and amdgpu_cs_parser_bos().
>> + * This provides a wrapper around the get_user_pages() call to provide
>> + * device accessible pages that back user memory.
>> + */
>> int amdgpu_ttm_tt_get_user_pages(struct ttm_tt *ttm, struct page **pages)
>> {
>> struct amdgpu_ttm_tt *gtt = (void *)ttm;
>> @@ -715,6 +841,7 @@ int amdgpu_ttm_tt_get_user_pages(struct ttm_tt *ttm, struct page **pages)
>> }
>> }
>>
>> + /* loop enough times using contiguous pages of memory */
>> do {
>> unsigned num_pages = ttm->num_pages - pinned;
>> uint64_t userptr = gtt->userptr + pinned * PAGE_SIZE;
>> @@ -748,6 +875,14 @@ int amdgpu_ttm_tt_get_user_pages(struct ttm_tt *ttm, struct page **pages)
>> return r;
>> }
>>
>> +/**
>> + * amdgpu_ttm_tt_set_user_pages - Copy pages in, putting old pages
>> + * as necessary.
>> + *
>> + * Called by amdgpu_cs_list_validate(). This creates the page list
>> + * that backs user memory and will ultimately be mapped into the device
>> + * address space.
>> + */
>> void amdgpu_ttm_tt_set_user_pages(struct ttm_tt *ttm, struct page **pages)
>> {
>> struct amdgpu_ttm_tt *gtt = (void *)ttm;
>> @@ -762,6 +897,11 @@ void amdgpu_ttm_tt_set_user_pages(struct ttm_tt *ttm, struct page **pages)
>> }
>> }
>>
>> +/**
>> + * amdgpu_ttm_tt_mark_user_page - Mark pages as dirty
>> + *
>> + * Called while unpinning userptr pages
>> + */
>> void amdgpu_ttm_tt_mark_user_pages(struct ttm_tt *ttm)
>> {
>> struct amdgpu_ttm_tt *gtt = (void *)ttm;
>> @@ -780,7 +920,12 @@ void amdgpu_ttm_tt_mark_user_pages(struct ttm_tt *ttm)
>> }
>> }
>>
>> -/* prepare the sg table with the user pages */
>> +/**
>> + * amdgpu_ttm_tt_pin_userptr - prepare the sg table with the
>> + * user pages
>> + *
>> + * Called by amdgpu_ttm_backend_bind()
>> + **/
>> static int amdgpu_ttm_tt_pin_userptr(struct ttm_tt *ttm)
>> {
>> struct amdgpu_device *adev = amdgpu_ttm_adev(ttm->bdev);
>> @@ -792,17 +937,20 @@ static int amdgpu_ttm_tt_pin_userptr(struct ttm_tt *ttm)
>> enum dma_data_direction direction = write ?
>> DMA_BIDIRECTIONAL : DMA_TO_DEVICE;
>>
>> + /* Allocate an SG array and squash pages into it */
>> r = sg_alloc_table_from_pages(ttm->sg, ttm->pages, ttm->num_pages, 0,
>> ttm->num_pages << PAGE_SHIFT,
>> GFP_KERNEL);
>> if (r)
>> goto release_sg;
>>
>> + /* Map SG to device */
>> r = -ENOMEM;
>> nents = dma_map_sg(adev->dev, ttm->sg->sgl, ttm->sg->nents, direction);
>> if (nents != ttm->sg->nents)
>> goto release_sg;
>>
>> + /* convert SG to linear array of pages and dma addresses */
>> drm_prime_sg_to_page_addr_arrays(ttm->sg, ttm->pages,
>> gtt->ttm.dma_address, ttm->num_pages);
>>
>> @@ -813,6 +961,9 @@ static int amdgpu_ttm_tt_pin_userptr(struct ttm_tt *ttm)
>> return r;
>> }
>>
>> +/**
>> + * amdgpu_ttm_tt_unpin_userptr - Unpin and unmap userptr pages
>> + */
>> static void amdgpu_ttm_tt_unpin_userptr(struct ttm_tt *ttm)
>> {
>> struct amdgpu_device *adev = amdgpu_ttm_adev(ttm->bdev);
>> @@ -826,14 +977,22 @@ static void amdgpu_ttm_tt_unpin_userptr(struct ttm_tt *ttm)
>> if (!ttm->sg->sgl)
>> return;
>>
>> - /* free the sg table and pages again */
>> + /* unmap the pages mapped to the device */
>> dma_unmap_sg(adev->dev, ttm->sg->sgl, ttm->sg->nents, direction);
>>
>> + /* mark the pages as dirty */
>> amdgpu_ttm_tt_mark_user_pages(ttm);
>>
>> sg_free_table(ttm->sg);
>> }
>>
>> +
>> +/**
>> + * amdgpu_ttm_backend_bind - Bind GTT memory
>> + *
>> + * Called by ttm_tt_bind() on behalf of ttm_bo_handle_move_mem().
>> + * This handles binding GTT memory to the device address space.
>> + */
>> static int amdgpu_ttm_backend_bind(struct ttm_tt *ttm,
>> struct ttm_mem_reg *bo_mem)
>> {
>> @@ -864,7 +1023,10 @@ static int amdgpu_ttm_backend_bind(struct ttm_tt *ttm,
>> return 0;
>> }
>>
>> + /* compute PTE flags relevant to this BO memory */
>> flags = amdgpu_ttm_tt_pte_flags(adev, ttm, bo_mem);
>> +
>> + /* bind pages into GART page tables */
>> gtt->offset = (u64)bo_mem->start << PAGE_SHIFT;
>> r = amdgpu_gart_bind(adev, gtt->offset, ttm->num_pages,
>> ttm->pages, gtt->ttm.dma_address, flags);
>> @@ -875,6 +1037,9 @@ static int amdgpu_ttm_backend_bind(struct ttm_tt *ttm,
>> return r;
>> }
>>
>> +/**
>> + * amdgpu_ttm_alloc_gart - Allocate GART memory for buffer object
>> + */
>> int amdgpu_ttm_alloc_gart(struct ttm_buffer_object *bo)
>> {
>> struct amdgpu_device *adev = amdgpu_ttm_adev(bo->bdev);
>> @@ -890,6 +1055,7 @@ int amdgpu_ttm_alloc_gart(struct ttm_buffer_object *bo)
>> amdgpu_gtt_mgr_has_gart_addr(&bo->mem))
>> return 0;
>>
>> + /* allocate GTT space */
>> tmp = bo->mem;
>> tmp.mm_node = NULL;
>> placement.num_placement = 1;
>> @@ -905,7 +1071,10 @@ int amdgpu_ttm_alloc_gart(struct ttm_buffer_object *bo)
>> if (unlikely(r))
>> return r;
>>
>> + /* compute PTE flags for this buffer object */
>> flags = amdgpu_ttm_tt_pte_flags(adev, bo->ttm, &tmp);
>> +
>> + /* Bind pages */
>> gtt->offset = (u64)tmp.start << PAGE_SHIFT;
>> r = amdgpu_gart_bind(adev, gtt->offset, bo->ttm->num_pages,
>> bo->ttm->pages, gtt->ttm.dma_address, flags);
>> @@ -922,6 +1091,12 @@ int amdgpu_ttm_alloc_gart(struct ttm_buffer_object *bo)
>> return 0;
>> }
>>
>> +/**
>> + * amdgpu_ttm_recover_gart - Rebind GTT pages
>> + *
>> + * Called by amdgpu_gtt_mgr_recover() from amdgpu_device_reset() to
>> + * rebind GTT pages during a GPU reset.
>> + */
>> int amdgpu_ttm_recover_gart(struct ttm_buffer_object *tbo)
>> {
>> struct amdgpu_device *adev = amdgpu_ttm_adev(tbo->bdev);
>> @@ -941,12 +1116,19 @@ int amdgpu_ttm_recover_gart(struct ttm_buffer_object *tbo)
>> return r;
>> }
>>
>> +/**
>> + * amdgpu_ttm_backend_unbind - Unbind GTT mapped pages
>> + *
>> + * Called by ttm_tt_unbind() on behalf of ttm_bo_move_ttm() and
>> + * ttm_tt_destroy().
>> + */
>> static int amdgpu_ttm_backend_unbind(struct ttm_tt *ttm)
>> {
>> struct amdgpu_device *adev = amdgpu_ttm_adev(ttm->bdev);
>> struct amdgpu_ttm_tt *gtt = (void *)ttm;
>> int r;
>>
>> + /* if the pages have userptr pinning then clear that first */
>> if (gtt->userptr)
>> amdgpu_ttm_tt_unpin_userptr(ttm);
>>
>> @@ -975,6 +1157,13 @@ static struct ttm_backend_func amdgpu_backend_func = {
>> .destroy = &amdgpu_ttm_backend_destroy,
>> };
>>
>> +/**
>> + * amdgpu_ttm_tt_create - Create a ttm_tt object for a given BO
>> + *
>> + * @bo: The buffer object to create a GTT ttm_tt object around
>> + *
>> + * Called by ttm_tt_create().
>> + */
>> static struct ttm_tt *amdgpu_ttm_tt_create(struct ttm_buffer_object *bo,
>> uint32_t page_flags)
>> {
>> @@ -988,6 +1177,8 @@ static struct ttm_tt *amdgpu_ttm_tt_create(struct ttm_buffer_object *bo,
>> return NULL;
>> }
>> gtt->ttm.ttm.func = &amdgpu_backend_func;
>> +
>> + /* allocate space for the uninitialized page entries */
>> if (ttm_sg_tt_init(>t->ttm, bo, page_flags)) {
>> kfree(gtt);
>> return NULL;
>> @@ -995,6 +1186,12 @@ static struct ttm_tt *amdgpu_ttm_tt_create(struct ttm_buffer_object *bo,
>> return >t->ttm.ttm;
>> }
>>
>> +/**
>> + * amdgpu_ttm_tt_populate - Map GTT pages visible to the device
>> + *
>> + * Map the pages of a ttm_tt object to an address space visible
>> + * to the underlying device.
>> + */
>> static int amdgpu_ttm_tt_populate(struct ttm_tt *ttm,
>> struct ttm_operation_ctx *ctx)
>> {
>> @@ -1002,6 +1199,7 @@ static int amdgpu_ttm_tt_populate(struct ttm_tt *ttm,
>> struct amdgpu_ttm_tt *gtt = (void *)ttm;
>> bool slave = !!(ttm->page_flags & TTM_PAGE_FLAG_SG);
>>
>> + /* user pages are bound by amdgpu_ttm_tt_pin_userptr() */
>> if (gtt && gtt->userptr) {
>> ttm->sg = kzalloc(sizeof(struct sg_table), GFP_KERNEL);
>> if (!ttm->sg)
>> @@ -1026,9 +1224,17 @@ static int amdgpu_ttm_tt_populate(struct ttm_tt *ttm,
>> }
>> #endif
>>
>> + /* fall back to generic helper to populate the page array
>> + * and map them to the device */
>> return ttm_populate_and_map_pages(adev->dev, >t->ttm, ctx);
>> }
>>
>> +/**
>> + * amdgpu_ttm_tt_unpopulate - unmap GTT pages and unpopulate page arrays
>> + *
>> + * Unmaps pages of a ttm_tt object from the device address space and
>> + * unpopulates the page array backing it.
>> + */
>> static void amdgpu_ttm_tt_unpopulate(struct ttm_tt *ttm)
>> {
>> struct amdgpu_device *adev;
>> @@ -1054,9 +1260,21 @@ static void amdgpu_ttm_tt_unpopulate(struct ttm_tt *ttm)
>> }
>> #endif
>>
>> + /* fall back to generic helper to unmap and unpopulate array */
>> ttm_unmap_and_unpopulate_pages(adev->dev, >t->ttm);
>> }
>>
>> +/**
>> + * amdgpu_ttm_tt_set_userptr - Initialize userptr GTT ttm_tt
>> + * for the current task
>> + *
>> + * @ttm: The ttm_tt object to bind this userptr object to
>> + * @addr: The address in the current tasks VM space to use
>> + * @flags: Requirements of userptr object.
>> + *
>> + * Called by amdgpu_gem_userptr_ioctl() to bind userptr pages
>> + * to current task
>> + */
>> int amdgpu_ttm_tt_set_userptr(struct ttm_tt *ttm, uint64_t addr,
>> uint32_t flags)
>> {
>> @@ -1076,6 +1294,9 @@ int amdgpu_ttm_tt_set_userptr(struct ttm_tt *ttm, uint64_t addr,
>> return 0;
>> }
>>
>> +/**
>> + * amdgpu_ttm_tt_get_usermm - Return memory manager for ttm_tt object
>> + */
>> struct mm_struct *amdgpu_ttm_tt_get_usermm(struct ttm_tt *ttm)
>> {
>> struct amdgpu_ttm_tt *gtt = (void *)ttm;
>> @@ -1086,6 +1307,12 @@ struct mm_struct *amdgpu_ttm_tt_get_usermm(struct ttm_tt *ttm)
>> return gtt->usermm;
>> }
>>
>> +/**
>> + * amdgpu_ttm_tt_affect_userptr - Determine if a ttm_tt object lays
>> + * inside an address range for the
>> + * current task.
>> + *
>> + */
>> bool amdgpu_ttm_tt_affect_userptr(struct ttm_tt *ttm, unsigned long start,
>> unsigned long end)
>> {
>> @@ -1096,10 +1323,14 @@ bool amdgpu_ttm_tt_affect_userptr(struct ttm_tt *ttm, unsigned long start,
>> if (gtt == NULL || !gtt->userptr)
>> return false;
>>
>> + /* does the address lie within the span for the userptr memory? */
>> size = (unsigned long)gtt->ttm.ttm.num_pages * PAGE_SIZE;
>> if (gtt->userptr > end || gtt->userptr + size <= start)
>> return false;
>>
>> + /* Search the lists of tasks that hold this mapping and see
>> + * if current is one of them. If it is return false.
>> + */
>> spin_lock(>t->guptasklock);
>> list_for_each_entry(entry, >t->guptasks, list) {
>> if (entry->task == current) {
>> @@ -1114,6 +1345,10 @@ bool amdgpu_ttm_tt_affect_userptr(struct ttm_tt *ttm, unsigned long start,
>> return true;
>> }
>>
>> +/**
>> + * amdgpu_ttm_tt_userptr_invalidated - Has the ttm_tt object been
>> + * invalidated?
>> + */
>> bool amdgpu_ttm_tt_userptr_invalidated(struct ttm_tt *ttm,
>> int *last_invalidated)
>> {
>> @@ -1124,6 +1359,12 @@ bool amdgpu_ttm_tt_userptr_invalidated(struct ttm_tt *ttm,
>> return prev_invalidated != *last_invalidated;
>> }
>>
>> +/**
>> + * amdgpu_ttm_tt_userptr_needs_pages - Have the pages backing this
>> + * ttm_tt object been invalidated
>> + * since the last time they've
>> + * been set?
>> + */
>> bool amdgpu_ttm_tt_userptr_needs_pages(struct ttm_tt *ttm)
>> {
>> struct amdgpu_ttm_tt *gtt = (void *)ttm;
>> @@ -1134,6 +1375,9 @@ bool amdgpu_ttm_tt_userptr_needs_pages(struct ttm_tt *ttm)
>> return atomic_read(>t->mmu_invalidations) != gtt->last_set_pages;
>> }
>>
>> +/**
>> + * amdgpu_ttm_tt_is_readonly - Is the ttm_tt object read only?
>> + */
>> bool amdgpu_ttm_tt_is_readonly(struct ttm_tt *ttm)
>> {
>> struct amdgpu_ttm_tt *gtt = (void *)ttm;
>> @@ -1144,6 +1388,12 @@ bool amdgpu_ttm_tt_is_readonly(struct ttm_tt *ttm)
>> return !!(gtt->userflags & AMDGPU_GEM_USERPTR_READONLY);
>> }
>>
>> +/**
>> + * amdgpu_ttm_tt_pte_flags - Compute PTE flags for ttm_tt object
>> + *
>> + * @ttm: The ttm_tt object to compute the flags for
>> + * @mem: The memory registry backing this ttm_tt object
>> + */
>> uint64_t amdgpu_ttm_tt_pte_flags(struct amdgpu_device *adev, struct ttm_tt *ttm,
>> struct ttm_mem_reg *mem)
>> {
>> @@ -1168,6 +1418,16 @@ uint64_t amdgpu_ttm_tt_pte_flags(struct amdgpu_device *adev, struct ttm_tt *ttm,
>> return flags;
>> }
>>
>> +/**
>> + * amdgpu_ttm_bo_eviction_valuable - Check to see if we can evict
>> + * a buffer object.
>> + *
>> + * Return true if eviction is sensible. Called by
>> + * ttm_mem_evict_first() on behalf of ttm_bo_mem_force_space()
>> + * which tries to evict buffer objects until it can find space
>> + * for a new object and by ttm_bo_force_list_clean() which is
>> + * used to clean out a memory space.
>> + */
>> static bool amdgpu_ttm_bo_eviction_valuable(struct ttm_buffer_object *bo,
>> const struct ttm_place *place)
>> {
>> @@ -1214,6 +1474,19 @@ static bool amdgpu_ttm_bo_eviction_valuable(struct ttm_buffer_object *bo,
>> return ttm_bo_eviction_valuable(bo, place);
>> }
>>
>> +/**
>> + * amdgpu_ttm_access_memory - Read or Write memory that backs a
>> + * buffer object.
>> + *
>> + * @bo: The buffer object to read/write
>> + * @offset: Offset into buffer object
>> + * @buf: Secondary buffer to write/read from
>> + * @len: Length in bytes of access
>> + * @write: true if writing
>> + *
>> + * This is used to access VRAM that backs a buffer object via MMIO
>> + * access for debugging purposes.
>> + */
>> static int amdgpu_ttm_access_memory(struct ttm_buffer_object *bo,
>> unsigned long offset,
>> void *buf, int len, int write)
>> @@ -1390,13 +1663,22 @@ static int amdgpu_ttm_fw_reserve_vram_init(struct amdgpu_device *adev)
>> adev->fw_vram_usage.reserved_bo = NULL;
>> return r;
>> }
>> -
>> +/**
>> + * amdgpu_ttm_init - Init the memory management (ttm) as well as
>> + * various gtt/vram related fields.
>> + *
>> + * This initializes all of the memory space pools that the TTM layer
>> + * will need such as the GTT space (system memory mapped to the device),
>> + * VRAM (on-board memory), and on-chip memories (GDS, GWS, OA) which
>> + * can be mapped per VMID.
>> + */
>> int amdgpu_ttm_init(struct amdgpu_device *adev)
>> {
>> uint64_t gtt_size;
>> int r;
>> u64 vis_vram_limit;
>>
>> + /* initialize global references for vram/gtt */
>> r = amdgpu_ttm_global_init(adev);
>> if (r) {
>> return r;
>> @@ -1417,6 +1699,7 @@ int amdgpu_ttm_init(struct amdgpu_device *adev)
>> /* We opt to avoid OOM on system pages allocations */
>> adev->mman.bdev.no_retry = true;
>>
>> + /* Initialize VRAM pool with all of VRAM divided into pages */
>> r = ttm_bo_init_mm(&adev->mman.bdev, TTM_PL_VRAM,
>> adev->gmc.real_vram_size >> PAGE_SHIFT);
>> if (r) {
>> @@ -1446,6 +1729,10 @@ int amdgpu_ttm_init(struct amdgpu_device *adev)
>> return r;
>> }
>>
>> + /* allocate memory as required for VGA
>> + * This is used for VGA emulation and pre-OS scanout buffers to
>> + * avoid display artifacts while transitioning between pre-OS
>> + * and driver. */
>> if (adev->gmc.stolen_size) {
>> r = amdgpu_bo_create_kernel(adev, adev->gmc.stolen_size, PAGE_SIZE,
>> AMDGPU_GEM_DOMAIN_VRAM,
>> @@ -1457,6 +1744,8 @@ int amdgpu_ttm_init(struct amdgpu_device *adev)
>> DRM_INFO("amdgpu: %uM of VRAM memory ready\n",
>> (unsigned) (adev->gmc.real_vram_size / (1024 * 1024)));
>>
>> + /* Compute GTT size, either bsaed on 3/4th the size of RAM size
>> + * or whatever the user passed on module init */
>> if (amdgpu_gtt_size == -1) {
>> struct sysinfo si;
>>
>> @@ -1467,6 +1756,8 @@ int amdgpu_ttm_init(struct amdgpu_device *adev)
>> }
>> else
>> gtt_size = (uint64_t)amdgpu_gtt_size << 20;
>> +
>> + /* Initialize GTT memory pool */
>> r = ttm_bo_init_mm(&adev->mman.bdev, TTM_PL_TT, gtt_size >> PAGE_SHIFT);
>> if (r) {
>> DRM_ERROR("Failed initializing GTT heap.\n");
>> @@ -1475,6 +1766,7 @@ int amdgpu_ttm_init(struct amdgpu_device *adev)
>> DRM_INFO("amdgpu: %uM of GTT memory ready.\n",
>> (unsigned)(gtt_size / (1024 * 1024)));
>>
>> + /* Initialize various on-chip memory pools */
>> adev->gds.mem.total_size = adev->gds.mem.total_size << AMDGPU_GDS_SHIFT;
>> adev->gds.mem.gfx_partition_size = adev->gds.mem.gfx_partition_size << AMDGPU_GDS_SHIFT;
>> adev->gds.mem.cs_partition_size = adev->gds.mem.cs_partition_size << AMDGPU_GDS_SHIFT;
>> @@ -1514,6 +1806,7 @@ int amdgpu_ttm_init(struct amdgpu_device *adev)
>> }
>> }
>>
>> + /* Register debugfs entries for amdgpu_ttm */
>> r = amdgpu_ttm_debugfs_init(adev);
>> if (r) {
>> DRM_ERROR("Failed to init debugfs\n");
>> @@ -1522,11 +1815,19 @@ int amdgpu_ttm_init(struct amdgpu_device *adev)
>> return 0;
>> }
>>
>> +/**
>> + * amdgpu_ttm_late_init - Handle any late initialization for
>> + * amdgpu_ttm
>> + */
>> void amdgpu_ttm_late_init(struct amdgpu_device *adev)
>> {
>> + /* return the VGA stolen memory (if any) back to VRAM */
>> amdgpu_bo_free_kernel(&adev->stolen_vga_memory, NULL, NULL);
>> }
>>
>> +/**
>> + * amdgpu_ttm_fini - De-initialize the TTM memory pools
>> + */
>> void amdgpu_ttm_fini(struct amdgpu_device *adev)
>> {
>> if (!adev->mman.initialized)
>> @@ -1854,6 +2155,11 @@ static const struct drm_info_list amdgpu_ttm_debugfs_list[] = {
>> #endif
>> };
>>
>> +/**
>> + * amdgpu_ttm_vram_read - Linear read access to VRAM
>> + *
>> + * Accesses VRAM via MMIO for debugging purposes.
>> + */
>> static ssize_t amdgpu_ttm_vram_read(struct file *f, char __user *buf,
>> size_t size, loff_t *pos)
>> {
>> @@ -1893,6 +2199,11 @@ static ssize_t amdgpu_ttm_vram_read(struct file *f, char __user *buf,
>> return result;
>> }
>>
>> +/**
>> + * amdgpu_ttm_vram_write - Linear write access to VRAM
>> + *
>> + * Accesses VRAM via MMIO for debugging purposes.
>> + */
>> static ssize_t amdgpu_ttm_vram_write(struct file *f, const char __user *buf,
>> size_t size, loff_t *pos)
>> {
>> @@ -1941,6 +2252,9 @@ static const struct file_operations amdgpu_ttm_vram_fops = {
>>
>> #ifdef CONFIG_DRM_AMDGPU_GART_DEBUGFS
>>
>> +/**
>> + * amdgpu_ttm_gtt_read - Linear read access to GTT memory
>> + */
>> static ssize_t amdgpu_ttm_gtt_read(struct file *f, char __user *buf,
>> size_t size, loff_t *pos)
>> {
>> @@ -1988,6 +2302,13 @@ static const struct file_operations amdgpu_ttm_gtt_fops = {
>>
>> #endif
>>
>> +/**
>> + * amdgpu_iomem_read - Virtual read access to GPU mapped memory
>> + *
>> + * This function is used to read memory that has been mapped to the
>> + * GPU and the known addresses are not physical addresses but instead
>> + * bus addresses (e.g., what you'd put in an IB or ring buffer).
>> + */
>> static ssize_t amdgpu_iomem_read(struct file *f, char __user *buf,
>> size_t size, loff_t *pos)
>> {
>> @@ -1996,6 +2317,7 @@ static ssize_t amdgpu_iomem_read(struct file *f, char __user *buf,
>> ssize_t result = 0;
>> int r;
>>
>> + /* retrieve the IOMMU domain if any for this device */
>> dom = iommu_get_domain_for_dev(adev->dev);
>>
>> while (size) {
>> @@ -2008,6 +2330,10 @@ static ssize_t amdgpu_iomem_read(struct file *f, char __user *buf,
>>
>> bytes = bytes < size ? bytes : size;
>>
>> + /* Translate the bus address to a physical address. If
>> + * the domain is NULL it means there is no IOMMU active
>> + * and the address translation is the identity
>> + */
>> addr = dom ? iommu_iova_to_phys(dom, addr) : addr;
>>
>> pfn = addr >> PAGE_SHIFT;
>> @@ -2032,6 +2358,13 @@ static ssize_t amdgpu_iomem_read(struct file *f, char __user *buf,
>> return result;
>> }
>>
>> +/**
>> + * amdgpu_iomem_write - Virtual write access to GPU mapped memory
>> + *
>> + * This function is used to write memory that has been mapped to the
>> + * GPU and the known addresses are not physical addresses but instead
>> + * bus addresses (e.g., what you'd put in an IB or ring buffer).
>> + */
>> static ssize_t amdgpu_iomem_write(struct file *f, const char __user *buf,
>> size_t size, loff_t *pos)
>> {
>> --
>> 2.14.3
>>
>> _______________________________________________
>> amd-gfx mailing list
>> amd-gfx at lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/amd-gfx
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