Jason Gunthorpe
2019-Oct-28 20:10 UTC
[Nouveau] [PATCH v2 14/15] drm/amdgpu: Use mmu_range_notifier instead of hmm_mirror
From: Jason Gunthorpe <jgg at mellanox.com>
Convert the collision-retry lock around hmm_range_fault to use the one now
provided by the mmu_range 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_range_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.
Cc: Alex Deucher <alexander.deucher at amd.com>
Cc: Christian K?nig <christian.koenig at amd.com>
Cc: David (ChunMing) Zhou <David1.Zhou at amd.com>
Cc: amd-gfx at lists.freedesktop.org
Signed-off-by: Jason Gunthorpe <jgg at mellanox.com>
---
.../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c | 4 +
drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c | 14 +-
drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c | 148 ++----------------
drivers/gpu/drm/amd/amdgpu/amdgpu_mn.h | 49 ------
drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 76 ++++-----
5 files changed, 66 insertions(+), 225 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
index 47700302a08b7f..1bcedb9b477dce 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
@@ -1738,6 +1738,10 @@ static int update_invalid_user_pages(struct
amdkfd_process_info *process_info,
return ret;
}
+ /*
+ * FIXME: Cannot ignore the return code, must hold
+ * notifier_lock
+ */
amdgpu_ttm_tt_get_user_pages_done(bo->tbo.ttm);
/* Mark the BO as valid unless it was invalidated
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
index 2e53feed40e230..76771f5f0b60ab 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
@@ -607,8 +607,6 @@ static int amdgpu_cs_parser_bos(struct amdgpu_cs_parser *p,
e->tv.num_shared = 2;
amdgpu_bo_list_get_list(p->bo_list, &p->validated);
- if (p->bo_list->first_userptr != p->bo_list->num_entries)
- p->mn = amdgpu_mn_get(p->adev, AMDGPU_MN_TYPE_GFX);
INIT_LIST_HEAD(&duplicates);
amdgpu_vm_get_pd_bo(&fpriv->vm, &p->validated,
&p->vm_pd);
@@ -1291,11 +1289,11 @@ static int amdgpu_cs_submit(struct amdgpu_cs_parser *p,
if (r)
goto error_unlock;
- /* No memory allocation is allowed while holding the mn lock.
- * p->mn is hold until amdgpu_cs_submit is finished and fence is added
- * to BOs.
+ /* No memory allocation is allowed while holding the notifier lock.
+ * The lock is held until amdgpu_cs_submit is finished and fence is
+ * added to BOs.
*/
- amdgpu_mn_lock(p->mn);
+ mutex_lock(&p->adev->notifier_lock);
/* If userptr are invalidated after amdgpu_cs_parser_bos(), return
* -EAGAIN, drmIoctl in libdrm will restart the amdgpu_cs_ioctl.
@@ -1338,13 +1336,13 @@ static int amdgpu_cs_submit(struct amdgpu_cs_parser *p,
amdgpu_vm_move_to_lru_tail(p->adev, &fpriv->vm);
ttm_eu_fence_buffer_objects(&p->ticket, &p->validated,
p->fence);
- amdgpu_mn_unlock(p->mn);
+ mutex_unlock(&p->adev->notifier_lock);
return 0;
error_abort:
drm_sched_job_cleanup(&job->base);
- amdgpu_mn_unlock(p->mn);
+ mutex_unlock(&p->adev->notifier_lock);
error_unlock:
amdgpu_job_free(job);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
index 4ffd7b90f4d907..cb718a064eb491 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
@@ -50,28 +50,6 @@
#include "amdgpu.h"
#include "amdgpu_amdkfd.h"
-/**
- * amdgpu_mn_lock - take the write side lock for this notifier
- *
- * @mn: our notifier
- */
-void amdgpu_mn_lock(struct amdgpu_mn *mn)
-{
- if (mn)
- down_write(&mn->lock);
-}
-
-/**
- * amdgpu_mn_unlock - drop the write side lock for this notifier
- *
- * @mn: our notifier
- */
-void amdgpu_mn_unlock(struct amdgpu_mn *mn)
-{
- if (mn)
- up_write(&mn->lock);
-}
-
/**
* amdgpu_mn_invalidate_gfx - callback to notify about mm change
*
@@ -82,12 +60,19 @@ void amdgpu_mn_unlock(struct amdgpu_mn *mn)
* potentially dirty.
*/
static bool amdgpu_mn_invalidate_gfx(struct mmu_range_notifier *mrn,
- const struct mmu_notifier_range *range)
+ const struct mmu_notifier_range *range,
+ unsigned long cur_seq)
{
struct amdgpu_bo *bo = container_of(mrn, struct amdgpu_bo, notifier);
struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
long r;
+ /*
+ * FIXME: Must hold some lock shared with
+ * amdgpu_ttm_tt_get_user_pages_done()
+ */
+ mmu_range_set_seq(mrn, cur_seq);
+
/* FIXME: Is this necessary? */
if (!amdgpu_ttm_tt_affect_userptr(bo->tbo.ttm, range->start,
range->end))
@@ -119,11 +104,18 @@ static const struct mmu_range_notifier_ops
amdgpu_mn_gfx_ops = {
* evicting all user-mode queues of the process.
*/
static bool amdgpu_mn_invalidate_hsa(struct mmu_range_notifier *mrn,
- const struct mmu_notifier_range *range)
+ const struct mmu_notifier_range *range,
+ unsigned long cur_seq)
{
struct amdgpu_bo *bo = container_of(mrn, struct amdgpu_bo, notifier);
struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
+ /*
+ * FIXME: Must hold some lock shared with
+ * amdgpu_ttm_tt_get_user_pages_done()
+ */
+ mmu_range_set_seq(mrn, cur_seq);
+
/* FIXME: Is this necessary? */
if (!amdgpu_ttm_tt_affect_userptr(bo->tbo.ttm, range->start,
range->end))
@@ -143,92 +135,6 @@ static const struct mmu_range_notifier_ops
amdgpu_mn_hsa_ops = {
.invalidate = amdgpu_mn_invalidate_hsa,
};
-static int amdgpu_mn_sync_pagetables(struct hmm_mirror *mirror,
- const struct mmu_notifier_range *update)
-{
- struct amdgpu_mn *amn = container_of(mirror, struct amdgpu_mn, mirror);
-
- if (!mmu_notifier_range_blockable(update))
- return false;
-
- down_read(&amn->lock);
- up_read(&amn->lock);
- return 0;
-}
-
-/* Low bits of any reasonable mm pointer will be unused due to struct
- * alignment. Use these bits to make a unique key from the mm pointer
- * and notifier type.
- */
-#define AMDGPU_MN_KEY(mm, type) ((unsigned long)(mm) + (type))
-
-static struct hmm_mirror_ops amdgpu_hmm_mirror_ops[] = {
- [AMDGPU_MN_TYPE_GFX] = {
- .sync_cpu_device_pagetables = amdgpu_mn_sync_pagetables,
- },
- [AMDGPU_MN_TYPE_HSA] = {
- .sync_cpu_device_pagetables = amdgpu_mn_sync_pagetables,
- },
-};
-
-/**
- * amdgpu_mn_get - create HMM mirror context
- *
- * @adev: amdgpu device pointer
- * @type: type of MMU notifier context
- *
- * Creates a HMM mirror context for current->mm.
- */
-struct amdgpu_mn *amdgpu_mn_get(struct amdgpu_device *adev,
- enum amdgpu_mn_type type)
-{
- struct mm_struct *mm = current->mm;
- struct amdgpu_mn *amn;
- unsigned long key = AMDGPU_MN_KEY(mm, type);
- int r;
-
- mutex_lock(&adev->mn_lock);
- if (down_write_killable(&mm->mmap_sem)) {
- mutex_unlock(&adev->mn_lock);
- return ERR_PTR(-EINTR);
- }
-
- hash_for_each_possible(adev->mn_hash, amn, node, key)
- if (AMDGPU_MN_KEY(amn->mirror.hmm->mmu_notifier.mm,
- amn->type) == key)
- goto release_locks;
-
- amn = kzalloc(sizeof(*amn), GFP_KERNEL);
- if (!amn) {
- amn = ERR_PTR(-ENOMEM);
- goto release_locks;
- }
-
- amn->adev = adev;
- init_rwsem(&amn->lock);
- amn->type = type;
-
- amn->mirror.ops = &amdgpu_hmm_mirror_ops[type];
- r = hmm_mirror_register(&amn->mirror, mm);
- if (r)
- goto free_amn;
-
- hash_add(adev->mn_hash, &amn->node, AMDGPU_MN_KEY(mm, type));
-
-release_locks:
- up_write(&mm->mmap_sem);
- mutex_unlock(&adev->mn_lock);
-
- return amn;
-
-free_amn:
- up_write(&mm->mmap_sem);
- mutex_unlock(&adev->mn_lock);
- kfree(amn);
-
- return ERR_PTR(r);
-}
-
/**
* amdgpu_mn_register - register a BO for notifier updates
*
@@ -263,25 +169,3 @@ void amdgpu_mn_unregister(struct amdgpu_bo *bo)
mmu_range_notifier_remove(&bo->notifier);
bo->notifier.mm = NULL;
}
-
-/* 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 */
-};
-
-void amdgpu_hmm_init_range(struct hmm_range *range)
-{
- if (range) {
- range->flags = hmm_range_flags;
- range->values = hmm_range_values;
- range->pfn_shift = PAGE_SHIFT;
- }
-}
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.h
b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.h
index d73ab2947b22b2..a292238f75ebae 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.h
@@ -30,59 +30,10 @@
#include <linux/workqueue.h>
#include <linux/interval_tree.h>
-enum amdgpu_mn_type {
- AMDGPU_MN_TYPE_GFX,
- AMDGPU_MN_TYPE_HSA,
-};
-
-/**
- * struct amdgpu_mn
- *
- * @adev: amdgpu device pointer
- * @type: type of MMU notifier
- * @work: destruction work item
- * @node: hash table node to find structure by adev and mn
- * @lock: rw semaphore protecting the notifier nodes
- * @mirror: HMM mirror function support
- *
- * Data for each amdgpu device and process address space.
- */
-struct amdgpu_mn {
- /* constant after initialisation */
- struct amdgpu_device *adev;
- enum amdgpu_mn_type type;
-
- /* only used on destruction */
- struct work_struct work;
-
- /* protected by adev->mn_lock */
- struct hlist_node node;
-
- /* objects protected by lock */
- struct rw_semaphore lock;
-
-#ifdef CONFIG_HMM_MIRROR
- /* HMM mirror */
- struct hmm_mirror mirror;
-#endif
-};
-
#if defined(CONFIG_HMM_MIRROR)
-void amdgpu_mn_lock(struct amdgpu_mn *mn);
-void amdgpu_mn_unlock(struct amdgpu_mn *mn);
-struct amdgpu_mn *amdgpu_mn_get(struct amdgpu_device *adev,
- enum amdgpu_mn_type type);
int amdgpu_mn_register(struct amdgpu_bo *bo, unsigned long addr);
void amdgpu_mn_unregister(struct amdgpu_bo *bo);
-void amdgpu_hmm_init_range(struct hmm_range *range);
#else
-static inline void amdgpu_mn_lock(struct amdgpu_mn *mn) {}
-static inline void amdgpu_mn_unlock(struct amdgpu_mn *mn) {}
-static inline struct amdgpu_mn *amdgpu_mn_get(struct amdgpu_device *adev,
- enum amdgpu_mn_type type)
-{
- return NULL;
-}
static inline int amdgpu_mn_register(struct amdgpu_bo *bo, unsigned long addr)
{
DRM_WARN_ONCE("HMM_MIRROR kernel config option is not enabled, "
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index c0e41f1f0c2365..65d9824b54f2a9 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -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 +794,27 @@ 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;
+ struct hmm_range *range;
unsigned long start = gtt->userptr;
struct vm_area_struct *vma;
- struct hmm_range *range;
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;
@@ -811,30 +823,24 @@ 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);
+ range->notifier_seq = mmu_range_read_begin(&bo->notifier);
down_read(&mm->mmap_sem);
vma = find_vma(mm, start);
@@ -855,10 +861,10 @@ int amdgpu_ttm_tt_get_user_pages(struct amdgpu_bo *bo,
struct page **pages)
goto out_free_pfns;
for (i = 0; i < ttm->num_pages; i++) {
- pages[i] = hmm_device_entry_to_page(range, pfns[i]);
+ 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 +879,7 @@ 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:
@@ -903,9 +908,8 @@ 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);
-
+ r = mmu_range_read_retry(gtt->range->notifier,
+ gtt->range->notifier_seq);
kvfree(gtt->range->pfns);
kfree(gtt->range);
gtt->range = NULL;
--
2.23.0
Jason Gunthorpe
2019-Oct-29 19:25 UTC
[Nouveau] [PATCH v2 14/15] drm/amdgpu: Use mmu_range_notifier instead of hmm_mirror
On Tue, Oct 29, 2019 at 07:22:37PM +0000, Yang, Philip wrote:> Hi Jason, > > I did quick test after merging amd-staging-drm-next with the > mmu_notifier branch, which includes this set changes. The test result > has different failures, app stuck intermittently, GUI no display etc. I > am understanding the changes and will try to figure out the cause.Thanks! I'm not surprised by this given how difficult this patch was to make. Let me know if I can assist in any way Please ensure to run with lockdep enabled.. Your symptops sounds sort of like deadlocking? Regards, Jason
Possibly Parallel Threads
- [PATCH v2 00/15] Consolidate the mmu notifier interval_tree and locking
- [PATCH hmm v3 00/14] Consolidate the mmu notifier interval_tree and locking
- [PATCH v2 14/15] drm/amdgpu: Use mmu_range_notifier instead of hmm_mirror
- [PATCH v2 14/15] drm/amdgpu: Use mmu_range_notifier instead of hmm_mirror
- [PATCH v2 13/15] drm/amdgpu: Use mmu_range_insert instead of hmm_mirror