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drm/amdgpu: Use mmu_interval_notifier instead of hmm_mirror

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Convert the collision-retry lock around hmm_range_fault to use the one now
provided by the mmu_interval notifier.

Although this driver does not seem to use the collision retry lock that
hmm provides correctly, it can still be converted over to use the
mmu_interval_notifier api instead of hmm_mirror without too much trouble.

This also deletes another place where a driver is associating additional
data (struct amdgpu_mn) with a mmu_struct.

Link: https://lore.kernel.org/r/20191112202231.3856-13-jgg@ziepe.ca
Signed-off-by: Philip Yang <Philip.Yang@amd.com>
Reviewed-by: Philip Yang <Philip.Yang@amd.com>
Tested-by: Philip Yang <Philip.Yang@amd.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
This commit is contained in:
Jason Gunthorpe
2019-11-12 16:22:29 -04:00
parent 62914a99de
commit 81fa1af31b
5 changed files with 94 additions and 237 deletions
Download Patch File Download Diff File Expand all files Collapse all files

116
drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
View File

@@ -773,6 +773,20 @@ struct amdgpu_ttm_tt {
#endif
};
#ifdef CONFIG_DRM_AMDGPU_USERPTR
/* flags used by HMM internal, not related to CPU/GPU PTE flags */
static const uint64_t hmm_range_flags[HMM_PFN_FLAG_MAX] = {
(1 << 0), /* HMM_PFN_VALID */
(1 << 1), /* HMM_PFN_WRITE */
0 /* HMM_PFN_DEVICE_PRIVATE */
};
static const uint64_t hmm_range_values[HMM_PFN_VALUE_MAX] = {
0xfffffffffffffffeUL, /* HMM_PFN_ERROR */
0, /* HMM_PFN_NONE */
0xfffffffffffffffcUL /* HMM_PFN_SPECIAL */
};
/**
* amdgpu_ttm_tt_get_user_pages - get device accessible pages that back user
* memory and start HMM tracking CPU page table update
@@ -780,29 +794,28 @@ struct amdgpu_ttm_tt {
* Calling function must call amdgpu_ttm_tt_userptr_range_done() once and only
* once afterwards to stop HMM tracking
*/
#if IS_ENABLED(CONFIG_DRM_AMDGPU_USERPTR)
#define MAX_RETRY_HMM_RANGE_FAULT 16
int amdgpu_ttm_tt_get_user_pages(struct amdgpu_bo *bo, struct page **pages)
{
struct hmm_mirror *mirror = bo->mn ? &bo->mn->mirror : NULL;
struct ttm_tt *ttm = bo->tbo.ttm;
struct amdgpu_ttm_tt *gtt = (void *)ttm;
struct mm_struct *mm;
unsigned long start = gtt->userptr;
struct vm_area_struct *vma;
struct hmm_range *range;
unsigned long timeout;
struct mm_struct *mm;
unsigned long i;
uint64_t *pfns;
int r = 0;
if (unlikely(!mirror)) {
DRM_DEBUG_DRIVER("Failed to get hmm_mirror\n");
mm = bo->notifier.mm;
if (unlikely(!mm)) {
DRM_DEBUG_DRIVER("BO is not registered?\n");
return -EFAULT;
}
mm = mirror->hmm->mmu_notifier.mm;
/* Another get_user_pages is running at the same time?? */
if (WARN_ON(gtt->range))
return -EFAULT;
if (!mmget_not_zero(mm)) /* Happens during process shutdown */
return -ESRCH;
@@ -811,31 +824,23 @@ int amdgpu_ttm_tt_get_user_pages(struct amdgpu_bo *bo, struct page **pages)
r = -ENOMEM;
goto out;
}
range->notifier = &bo->notifier;
range->flags = hmm_range_flags;
range->values = hmm_range_values;
range->pfn_shift = PAGE_SHIFT;
range->start = bo->notifier.interval_tree.start;
range->end = bo->notifier.interval_tree.last + 1;
range->default_flags = hmm_range_flags[HMM_PFN_VALID];
if (!amdgpu_ttm_tt_is_readonly(ttm))
range->default_flags |= range->flags[HMM_PFN_WRITE];
pfns = kvmalloc_array(ttm->num_pages, sizeof(*pfns), GFP_KERNEL);
if (unlikely(!pfns)) {
range->pfns = kvmalloc_array(ttm->num_pages, sizeof(*range->pfns),
GFP_KERNEL);
if (unlikely(!range->pfns)) {
r = -ENOMEM;
goto out_free_ranges;
}
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;
range->start = start;
range->end = start + ttm->num_pages * PAGE_SIZE;
hmm_range_register(range, mirror);
/*
* 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);
down_read(&mm->mmap_sem);
vma = find_vma(mm, start);
if (unlikely(!vma || start < vma->vm_start)) {
@@ -847,18 +852,31 @@ int amdgpu_ttm_tt_get_user_pages(struct amdgpu_bo *bo, struct page **pages)
r = -EPERM;
goto out_unlock;
}
up_read(&mm->mmap_sem);
timeout = jiffies + msecs_to_jiffies(HMM_RANGE_DEFAULT_TIMEOUT);
retry:
range->notifier_seq = mmu_interval_read_begin(&bo->notifier);
down_read(&mm->mmap_sem);
r = hmm_range_fault(range, 0);
up_read(&mm->mmap_sem);
if (unlikely(r < 0))
if (unlikely(r <= 0)) {
/*
* FIXME: This timeout should encompass the retry from
* mmu_interval_read_retry() as well.
*/
if ((r == 0 || r == -EBUSY) && !time_after(jiffies, timeout))
goto retry;
goto out_free_pfns;
}
for (i = 0; i < ttm->num_pages; i++) {
pages[i] = hmm_device_entry_to_page(range, pfns[i]);
/* FIXME: The pages cannot be touched outside the notifier_lock */
pages[i] = hmm_device_entry_to_page(range, range->pfns[i]);
if (unlikely(!pages[i])) {
pr_err("Page fault failed for pfn[%lu] = 0x%llx\n",
i, pfns[i]);
i, range->pfns[i]);
r = -ENOMEM;
goto out_free_pfns;
@@ -873,8 +891,7 @@ int amdgpu_ttm_tt_get_user_pages(struct amdgpu_bo *bo, struct page **pages)
out_unlock:
up_read(&mm->mmap_sem);
out_free_pfns:
hmm_range_unregister(range);
kvfree(pfns);
kvfree(range->pfns);
out_free_ranges:
kfree(range);
out:
@@ -903,15 +920,18 @@ bool amdgpu_ttm_tt_get_user_pages_done(struct ttm_tt *ttm)
"No user pages to check\n");
if (gtt->range) {
r = hmm_range_valid(gtt->range);
hmm_range_unregister(gtt->range);
/*
* FIXME: Must always hold notifier_lock for this, and must
* not ignore the return code.
*/
r = mmu_interval_read_retry(gtt->range->notifier,
gtt->range->notifier_seq);
kvfree(gtt->range->pfns);
kfree(gtt->range);
gtt->range = NULL;
}
return r;
return !r;
}
#endif
@@ -992,10 +1012,18 @@ 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->range &&
ttm->pages[0] == hmm_device_entry_to_page(gtt->range,
gtt->range->pfns[0]))
WARN_ONCE(1, "Missing get_user_page_done\n");
if (gtt->range) {
unsigned long i;
for (i = 0; i < ttm->num_pages; i++) {
if (ttm->pages[i] !=
hmm_device_entry_to_page(gtt->range,
gtt->range->pfns[i]))
break;
}
WARN((i == ttm->num_pages), "Missing get_user_page_done\n");
}
#endif
}