Commit 66c45500 authored by Philip Yang's avatar Philip Yang Committed by Alex Deucher
Browse files

drm/amdgpu: use new HMM APIs and helpers 



HMM provides new APIs and helps in kernel 5.2-rc1 to simplify driver
path. The old hmm APIs are deprecated and will be removed in future.

Below are changes in driver:

1. Change hmm_vma_fault to hmm_range_register and hmm_range_fault which
supports range with multiple vmas, remove the multiple vmas handle path
and data structure.
2. Change hmm_vma_range_done to hmm_range_unregister.
3. Use default flags to avoid pre-fill pfn arrays.
4. Use new hmm_device_ helpers.

Signed-off-by: default avatarPhilip Yang <Philip.Yang@amd.com>
Reviewed-by: default avatarFelix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 8252562d

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

+0 −1
Original line number Diff line number Diff line
@@ -519,7 +519,6 @@ void amdgpu_hmm_init_range(struct hmm_range *range) 
		range->flags = hmm_range_flags;

		range->values = hmm_range_values;

		range->pfn_shift = PAGE_SHIFT;

		range->pfns = NULL;

		INIT_LIST_HEAD(&range->list);

	}

}

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

+68 −84
Original line number Diff line number Diff line
@@ -711,8 +711,7 @@ struct amdgpu_ttm_tt { 
	struct task_struct	*usertask;

	uint32_t		userflags;

#if IS_ENABLED(CONFIG_DRM_AMDGPU_USERPTR)

	struct hmm_range	*ranges;

	int			nr_ranges;

	struct hmm_range	*range;

#endif

};
@@ -725,57 +724,36 @@ struct amdgpu_ttm_tt { 
 */

#if IS_ENABLED(CONFIG_DRM_AMDGPU_USERPTR)



/* Support Userptr pages cross max 16 vmas */

#define MAX_NR_VMAS	(16)

#define MAX_RETRY_HMM_RANGE_FAULT	16



int amdgpu_ttm_tt_get_user_pages(struct ttm_tt *ttm, struct page **pages)

{

	struct amdgpu_ttm_tt *gtt = (void *)ttm;

	struct mm_struct *mm = gtt->usertask->mm;

	unsigned long start = gtt->userptr;

	unsigned long end = start + ttm->num_pages * PAGE_SIZE;

	struct vm_area_struct *vma = NULL, *vmas[MAX_NR_VMAS];

	struct hmm_range *ranges;

	unsigned long nr_pages, i;

	uint64_t *pfns, f;

	struct vm_area_struct *vma;

	struct hmm_range *range;

	unsigned long i;

	uint64_t *pfns;

	int retry = 0;

	int r = 0;



	if (!mm) /* Happens during process shutdown */

		return -ESRCH;



	down_read(&mm->mmap_sem);



	/* user pages may cross multiple VMAs */

	gtt->nr_ranges = 0;

	do {

		unsigned long vm_start;



		if (gtt->nr_ranges >= MAX_NR_VMAS) {

			DRM_ERROR("Too many VMAs in userptr range\n");

			r = -EFAULT;

			goto out;

		}



		vm_start = vma ? vma->vm_end : start;

		vma = find_vma(mm, vm_start);

		if (unlikely(!vma || vm_start < vma->vm_start)) {

	vma = find_vma(mm, start);

	if (unlikely(!vma || start < vma->vm_start)) {

		r = -EFAULT;

		goto out;

	}

		vmas[gtt->nr_ranges++] = vma;

	} while (end > vma->vm_end);



	DRM_DEBUG_DRIVER("0x%lx nr_ranges %d pages 0x%lx\n",

		start, gtt->nr_ranges, ttm->num_pages);



	if (unlikely((gtt->userflags & AMDGPU_GEM_USERPTR_ANONONLY) &&

		vmas[0]->vm_file)) {

		vma->vm_file)) {

		r = -EPERM;

		goto out;

	}



	ranges = kvmalloc_array(gtt->nr_ranges, sizeof(*ranges), GFP_KERNEL);

	if (unlikely(!ranges)) {

	range = kzalloc(sizeof(*range), GFP_KERNEL);

	if (unlikely(!range)) {

		r = -ENOMEM;

		goto out;

	}
@@ -786,61 +764,67 @@ int amdgpu_ttm_tt_get_user_pages(struct ttm_tt *ttm, struct page **pages) 
		goto out_free_ranges;

	}



	for (i = 0; i < gtt->nr_ranges; i++)

		amdgpu_hmm_init_range(&ranges[i]);

	amdgpu_hmm_init_range(range);

	range->default_flags = range->flags[HMM_PFN_VALID];

	range->default_flags |= amdgpu_ttm_tt_is_readonly(ttm) ?

				0 : range->flags[HMM_PFN_WRITE];

	range->pfn_flags_mask = 0;

	range->pfns = pfns;

	hmm_range_register(range, mm, start,

			   start + ttm->num_pages * PAGE_SIZE, PAGE_SHIFT);



	f = ranges[0].flags[HMM_PFN_VALID];

	f |= amdgpu_ttm_tt_is_readonly(ttm) ?

				0 : ranges[0].flags[HMM_PFN_WRITE];

	memset64(pfns, f, ttm->num_pages);

retry:

	/*

	 * Just wait for range to be valid, safe to ignore return value as we

	 * will use the return value of hmm_range_fault() below under the

	 * mmap_sem to ascertain the validity of the range.

	 */

	hmm_range_wait_until_valid(range, HMM_RANGE_DEFAULT_TIMEOUT);



	for (nr_pages = 0, i = 0; i < gtt->nr_ranges; i++) {

		ranges[i].vma = vmas[i];

		ranges[i].start = max(start, vmas[i]->vm_start);

		ranges[i].end = min(end, vmas[i]->vm_end);

		ranges[i].pfns = pfns + nr_pages;

		nr_pages += (ranges[i].end - ranges[i].start) / PAGE_SIZE;

	down_read(&mm->mmap_sem);



		r = hmm_vma_fault(&ranges[i], true);

		if (unlikely(r))

			break;

	r = hmm_range_fault(range, true);

	if (unlikely(r < 0)) {

		if (likely(r == -EAGAIN)) {

			/*

			 * return -EAGAIN, mmap_sem is dropped

			 */

			if (retry++ < MAX_RETRY_HMM_RANGE_FAULT)

				goto retry;

			else

				pr_err("Retry hmm fault too many times\n");

		}

	if (unlikely(r)) {

		while (i--)

			hmm_vma_range_done(&ranges[i]);



		goto out_free_pfns;

		goto out_up_read;

	}



	up_read(&mm->mmap_sem);



	for (i = 0; i < ttm->num_pages; i++) {

		pages[i] = hmm_pfn_to_page(&ranges[0], pfns[i]);

		if (!pages[i]) {

		pages[i] = hmm_device_entry_to_page(range, pfns[i]);

		if (unlikely(!pages[i])) {

			pr_err("Page fault failed for pfn[%lu] = 0x%llx\n",

			       i, pfns[i]);

			goto out_invalid_pfn;

			r = -ENOMEM;



			goto out_free_pfns;

		}

	}

	gtt->ranges = ranges;



	gtt->range = range;



	return 0;



out_up_read:

	if (likely(r != -EAGAIN))

		up_read(&mm->mmap_sem);

out_free_pfns:

	hmm_range_unregister(range);

	kvfree(pfns);

out_free_ranges:

	kvfree(ranges);

	kfree(range);

out:

	up_read(&mm->mmap_sem);



	return r;



out_invalid_pfn:

	for (i = 0; i < gtt->nr_ranges; i++)

		hmm_vma_range_done(&ranges[i]);

	kvfree(pfns);

	kvfree(ranges);

	return -ENOMEM;

}



/**
@@ -853,23 +837,23 @@ bool amdgpu_ttm_tt_get_user_pages_done(struct ttm_tt *ttm) 
{

	struct amdgpu_ttm_tt *gtt = (void *)ttm;

	bool r = false;

	int i;



	if (!gtt || !gtt->userptr)

		return false;



	DRM_DEBUG_DRIVER("user_pages_done 0x%llx nr_ranges %d pages 0x%lx\n",

		gtt->userptr, gtt->nr_ranges, ttm->num_pages);

	DRM_DEBUG_DRIVER("user_pages_done 0x%llx pages 0x%lx\n",

		gtt->userptr, ttm->num_pages);



	WARN_ONCE(!gtt->ranges || !gtt->ranges[0].pfns,

	WARN_ONCE(!gtt->range || !gtt->range->pfns,

		"No user pages to check\n");



	if (gtt->ranges) {

		for (i = 0; i < gtt->nr_ranges; i++)

			r |= hmm_vma_range_done(&gtt->ranges[i]);

		kvfree(gtt->ranges[0].pfns);

		kvfree(gtt->ranges);

		gtt->ranges = NULL;

	if (gtt->range) {

		r = hmm_range_valid(gtt->range);

		hmm_range_unregister(gtt->range);



		kvfree(gtt->range->pfns);

		kfree(gtt->range);

		gtt->range = NULL;

	}



	return r;
@@ -953,9 +937,9 @@ static void amdgpu_ttm_tt_unpin_userptr(struct ttm_tt *ttm) 
	sg_free_table(ttm->sg);



#if IS_ENABLED(CONFIG_DRM_AMDGPU_USERPTR)

	if (gtt->ranges &&

	    ttm->pages[0] == hmm_pfn_to_page(&gtt->ranges[0],

					     gtt->ranges[0].pfns[0]))

	if (gtt->range &&

	    ttm->pages[0] == hmm_device_entry_to_page(gtt->range,

						      gtt->range->pfns[0]))

		WARN_ONCE(1, "Missing get_user_page_done\n");

#endif

}

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