[PATCH 0/3] Use HMM to replace get_user_pages

[PATCH 0/3] Use HMM to replace get_user_pages

[Yang, Philip]

Hi Christian,

Resend patch 1/3, 2/3, added Reviewed-by in comments.

Change in patch 3/3, amdgpu_cs_submit, amdgpu_cs_ioctl return -EAGAIN
to user space to retry cs_ioctl.

Regards,
Philip

Philip Yang (3):
  drm/amdgpu: use HMM mirror callback to replace mmu notifier v7
  drm/amdkfd: avoid HMM change cause circular lock dependency v2
  drm/amdgpu: replace get_user_pages with HMM address mirror helpers v8

 drivers/gpu/drm/amd/amdgpu/Kconfig            |   6 +-
 drivers/gpu/drm/amd/amdgpu/Makefile           |   2 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h    |   1 -
 .../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c  |  95 +++-------
 drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.h   |   2 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c        | 138 +++++---------
 drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c       |  14 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c        | 179 +++++++++---------
 drivers/gpu/drm/amd/amdgpu/amdgpu_mn.h        |   6 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c       | 178 +++++++----------
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h       |   3 +-
 .../drm/amd/amdkfd/kfd_device_queue_manager.c |  32 ++--
 12 files changed, 269 insertions(+), 387 deletions(-)

-- 
2.17.1

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[PATCH 1/3] drm/amdgpu: use HMM mirror callback to replace mmu notifier v7

[Yang, Philip]

Replace our MMU notifier with hmm_mirror_ops.sync_cpu_device_pagetables
callback. Enable CONFIG_HMM and CONFIG_HMM_MIRROR as a dependency in
DRM_AMDGPU_USERPTR Kconfig.

It supports both KFD userptr and gfx userptr paths.

Change-Id: Ie62c3c5e3c5b8521ab3b438d1eff2aa2a003835e
Signed-off-by: Philip Yang <Philip.Yang@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/Kconfig     |   6 +-
 drivers/gpu/drm/amd/amdgpu/Makefile    |   2 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c | 154 +++++++++++--------------
 drivers/gpu/drm/amd/amdgpu/amdgpu_mn.h |   2 +-
 4 files changed, 70 insertions(+), 94 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/Kconfig b/drivers/gpu/drm/amd/amdgpu/Kconfig
index 9221e5489069..960a63355705 100644
--- a/drivers/gpu/drm/amd/amdgpu/Kconfig
+++ b/drivers/gpu/drm/amd/amdgpu/Kconfig
@@ -26,10 +26,10 @@ config DRM_AMDGPU_CIK
 config DRM_AMDGPU_USERPTR
 	bool "Always enable userptr write support"
 	depends on DRM_AMDGPU
-	select MMU_NOTIFIER
+	select HMM_MIRROR
 	help
-	  This option selects CONFIG_MMU_NOTIFIER if it isn't already
-	  selected to enabled full userptr support.
+	  This option selects CONFIG_HMM and CONFIG_HMM_MIRROR if it
+	  isn't already selected to enabled full userptr support.
 
 config DRM_AMDGPU_GART_DEBUGFS
 	bool "Allow GART access through debugfs"
diff --git a/drivers/gpu/drm/amd/amdgpu/Makefile b/drivers/gpu/drm/amd/amdgpu/Makefile
index 466da5954a68..851001ced5e8 100644
--- a/drivers/gpu/drm/amd/amdgpu/Makefile
+++ b/drivers/gpu/drm/amd/amdgpu/Makefile
@@ -172,7 +172,7 @@ endif
 amdgpu-$(CONFIG_COMPAT) += amdgpu_ioc32.o
 amdgpu-$(CONFIG_VGA_SWITCHEROO) += amdgpu_atpx_handler.o
 amdgpu-$(CONFIG_ACPI) += amdgpu_acpi.o
-amdgpu-$(CONFIG_MMU_NOTIFIER) += amdgpu_mn.o
+amdgpu-$(CONFIG_HMM_MIRROR) += amdgpu_mn.o
 
 include $(FULL_AMD_PATH)/powerplay/Makefile
 
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
index 3e6823fdd939..e356867d2308 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
@@ -45,7 +45,7 @@
 
 #include <linux/firmware.h>
 #include <linux/module.h>
-#include <linux/mmu_notifier.h>
+#include <linux/hmm.h>
 #include <linux/interval_tree.h>
 #include <drm/drmP.h>
 #include <drm/drm.h>
@@ -58,7 +58,6 @@
  *
  * @adev: amdgpu device pointer
  * @mm: process address space
- * @mn: MMU notifier structure
  * @type: type of MMU notifier
  * @work: destruction work item
  * @node: hash table node to find structure by adev and mn
@@ -66,6 +65,7 @@
  * @objects: interval tree containing amdgpu_mn_nodes
  * @read_lock: mutex for recursive locking of @lock
  * @recursion: depth of recursion
+ * @mirror: HMM mirror function support
  *
  * Data for each amdgpu device and process address space.
  */
@@ -73,7 +73,6 @@ struct amdgpu_mn {
 	/* constant after initialisation */
 	struct amdgpu_device	*adev;
 	struct mm_struct	*mm;
-	struct mmu_notifier	mn;
 	enum amdgpu_mn_type	type;
 
 	/* only used on destruction */
@@ -85,8 +84,9 @@ struct amdgpu_mn {
 	/* objects protected by lock */
 	struct rw_semaphore	lock;
 	struct rb_root_cached	objects;
-	struct mutex		read_lock;
-	atomic_t		recursion;
+
+	/* HMM mirror */
+	struct hmm_mirror	mirror;
 };
 
 /**
@@ -103,7 +103,7 @@ struct amdgpu_mn_node {
 };
 
 /**
- * amdgpu_mn_destroy - destroy the MMU notifier
+ * amdgpu_mn_destroy - destroy the HMM mirror
  *
  * @work: previously sheduled work item
  *
@@ -129,28 +129,26 @@ static void amdgpu_mn_destroy(struct work_struct *work)
 	}
 	up_write(&amn->lock);
 	mutex_unlock(&adev->mn_lock);
-	mmu_notifier_unregister_no_release(&amn->mn, amn->mm);
+
+	hmm_mirror_unregister(&amn->mirror);
 	kfree(amn);
 }
 
 /**
- * amdgpu_mn_release - callback to notify about mm destruction
+ * amdgpu_hmm_mirror_release - callback to notify about mm destruction
  *
- * @mn: our notifier
- * @mm: the mm this callback is about
+ * @mirror: the HMM mirror (mm) this callback is about
  *
- * Shedule a work item to lazy destroy our notifier.
+ * Shedule a work item to lazy destroy HMM mirror.
  */
-static void amdgpu_mn_release(struct mmu_notifier *mn,
-			      struct mm_struct *mm)
+static void amdgpu_hmm_mirror_release(struct hmm_mirror *mirror)
 {
-	struct amdgpu_mn *amn = container_of(mn, struct amdgpu_mn, mn);
+	struct amdgpu_mn *amn = container_of(mirror, struct amdgpu_mn, mirror);
 
 	INIT_WORK(&amn->work, amdgpu_mn_destroy);
 	schedule_work(&amn->work);
 }
 
-
 /**
  * amdgpu_mn_lock - take the write side lock for this notifier
  *
@@ -181,14 +179,10 @@ void amdgpu_mn_unlock(struct amdgpu_mn *mn)
 static int amdgpu_mn_read_lock(struct amdgpu_mn *amn, bool blockable)
 {
 	if (blockable)
-		mutex_lock(&amn->read_lock);
-	else if (!mutex_trylock(&amn->read_lock))
+		down_read(&amn->lock);
+	else if (!down_read_trylock(&amn->lock))
 		return -EAGAIN;
 
-	if (atomic_inc_return(&amn->recursion) == 1)
-		down_read_non_owner(&amn->lock);
-	mutex_unlock(&amn->read_lock);
-
 	return 0;
 }
 
@@ -199,8 +193,7 @@ static int amdgpu_mn_read_lock(struct amdgpu_mn *amn, bool blockable)
  */
 static void amdgpu_mn_read_unlock(struct amdgpu_mn *amn)
 {
-	if (atomic_dec_return(&amn->recursion) == 0)
-		up_read_non_owner(&amn->lock);
+	up_read(&amn->lock);
 }
 
 /**
@@ -237,141 +230,126 @@ static void amdgpu_mn_invalidate_node(struct amdgpu_mn_node *node,
 /**
  * amdgpu_mn_invalidate_range_start_gfx - callback to notify about mm change
  *
- * @mn: our notifier
- * @range: mmu notifier context
+ * @mirror: the hmm_mirror (mm) is about to update
+ * @update: the update start, end address
  *
  * Block for operations on BOs to finish and mark pages as accessed and
  * potentially dirty.
  */
-static int amdgpu_mn_invalidate_range_start_gfx(struct mmu_notifier *mn,
-			const struct mmu_notifier_range *range)
+static int amdgpu_mn_sync_pagetables_gfx(struct hmm_mirror *mirror,
+			const struct hmm_update *update)
 {
-	struct amdgpu_mn *amn = container_of(mn, struct amdgpu_mn, mn);
+	struct amdgpu_mn *amn = container_of(mirror, struct amdgpu_mn, mirror);
+	unsigned long start = update->start;
+	unsigned long end = update->end;
+	bool blockable = update->blockable;
 	struct interval_tree_node *it;
-	unsigned long end;
 
 	/* notification is exclusive, but interval is inclusive */
-	end = range->end - 1;
+	end -= 1;
 
 	/* TODO we should be able to split locking for interval tree and
 	 * amdgpu_mn_invalidate_node
 	 */
-	if (amdgpu_mn_read_lock(amn, range->blockable))
+	if (amdgpu_mn_read_lock(amn, blockable))
 		return -EAGAIN;
 
-	it = interval_tree_iter_first(&amn->objects, range->start, end);
+	it = interval_tree_iter_first(&amn->objects, start, end);
 	while (it) {
 		struct amdgpu_mn_node *node;
 
-		if (!range->blockable) {
+		if (!blockable) {
 			amdgpu_mn_read_unlock(amn);
 			return -EAGAIN;
 		}
 
 		node = container_of(it, struct amdgpu_mn_node, it);
-		it = interval_tree_iter_next(it, range->start, end);
+		it = interval_tree_iter_next(it, start, end);
 
-		amdgpu_mn_invalidate_node(node, range->start, end);
+		amdgpu_mn_invalidate_node(node, start, end);
 	}
 
+	amdgpu_mn_read_unlock(amn);
+
 	return 0;
 }
 
 /**
  * amdgpu_mn_invalidate_range_start_hsa - callback to notify about mm change
  *
- * @mn: our notifier
- * @mm: the mm this callback is about
- * @start: start of updated range
- * @end: end of updated range
+ * @mirror: the hmm_mirror (mm) is about to update
+ * @update: the update start, end address
  *
  * We temporarily evict all BOs between start and end. This
  * necessitates evicting all user-mode queues of the process. The BOs
  * are restorted in amdgpu_mn_invalidate_range_end_hsa.
  */
-static int amdgpu_mn_invalidate_range_start_hsa(struct mmu_notifier *mn,
-			const struct mmu_notifier_range *range)
+static int amdgpu_mn_sync_pagetables_hsa(struct hmm_mirror *mirror,
+			const struct hmm_update *update)
 {
-	struct amdgpu_mn *amn = container_of(mn, struct amdgpu_mn, mn);
+	struct amdgpu_mn *amn = container_of(mirror, struct amdgpu_mn, mirror);
+	unsigned long start = update->start;
+	unsigned long end = update->end;
+	bool blockable = update->blockable;
 	struct interval_tree_node *it;
-	unsigned long end;
 
 	/* notification is exclusive, but interval is inclusive */
-	end = range->end - 1;
+	end -= 1;
 
-	if (amdgpu_mn_read_lock(amn, range->blockable))
+	if (amdgpu_mn_read_lock(amn, blockable))
 		return -EAGAIN;
 
-	it = interval_tree_iter_first(&amn->objects, range->start, end);
+	it = interval_tree_iter_first(&amn->objects, start, end);
 	while (it) {
 		struct amdgpu_mn_node *node;
 		struct amdgpu_bo *bo;
 
-		if (!range->blockable) {
+		if (!blockable) {
 			amdgpu_mn_read_unlock(amn);
 			return -EAGAIN;
 		}
 
 		node = container_of(it, struct amdgpu_mn_node, it);
-		it = interval_tree_iter_next(it, range->start, end);
+		it = interval_tree_iter_next(it, start, end);
 
 		list_for_each_entry(bo, &node->bos, mn_list) {
 			struct kgd_mem *mem = bo->kfd_bo;
 
 			if (amdgpu_ttm_tt_affect_userptr(bo->tbo.ttm,
-							 range->start,
-							 end))
-				amdgpu_amdkfd_evict_userptr(mem, range->mm);
+							 start, end))
+				amdgpu_amdkfd_evict_userptr(mem, amn->mm);
 		}
 	}
 
+	amdgpu_mn_read_unlock(amn);
+
 	return 0;
 }
 
-/**
- * amdgpu_mn_invalidate_range_end - callback to notify about mm change
- *
- * @mn: our notifier
- * @mm: the mm this callback is about
- * @start: start of updated range
- * @end: end of updated range
- *
- * Release the lock again to allow new command submissions.
+/* 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.
  */
-static void amdgpu_mn_invalidate_range_end(struct mmu_notifier *mn,
-			const struct mmu_notifier_range *range)
-{
-	struct amdgpu_mn *amn = container_of(mn, struct amdgpu_mn, mn);
-
-	amdgpu_mn_read_unlock(amn);
-}
+#define AMDGPU_MN_KEY(mm, type) ((unsigned long)(mm) + (type))
 
-static const struct mmu_notifier_ops amdgpu_mn_ops[] = {
+static struct hmm_mirror_ops amdgpu_hmm_mirror_ops[] = {
 	[AMDGPU_MN_TYPE_GFX] = {
-		.release = amdgpu_mn_release,
-		.invalidate_range_start = amdgpu_mn_invalidate_range_start_gfx,
-		.invalidate_range_end = amdgpu_mn_invalidate_range_end,
+		.sync_cpu_device_pagetables = amdgpu_mn_sync_pagetables_gfx,
+		.release = amdgpu_hmm_mirror_release
 	},
 	[AMDGPU_MN_TYPE_HSA] = {
-		.release = amdgpu_mn_release,
-		.invalidate_range_start = amdgpu_mn_invalidate_range_start_hsa,
-		.invalidate_range_end = amdgpu_mn_invalidate_range_end,
+		.sync_cpu_device_pagetables = amdgpu_mn_sync_pagetables_hsa,
+		.release = amdgpu_hmm_mirror_release
 	},
 };
 
-/* 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))
-
 /**
- * amdgpu_mn_get - create notifier context
+ * amdgpu_mn_get - create HMM mirror context
  *
  * @adev: amdgpu device pointer
  * @type: type of MMU notifier context
  *
- * Creates a notifier context for current->mm.
+ * Creates a HMM mirror context for current->mm.
  */
 struct amdgpu_mn *amdgpu_mn_get(struct amdgpu_device *adev,
 				enum amdgpu_mn_type type)
@@ -401,12 +379,10 @@ struct amdgpu_mn *amdgpu_mn_get(struct amdgpu_device *adev,
 	amn->mm = mm;
 	init_rwsem(&amn->lock);
 	amn->type = type;
-	amn->mn.ops = &amdgpu_mn_ops[type];
 	amn->objects = RB_ROOT_CACHED;
-	mutex_init(&amn->read_lock);
-	atomic_set(&amn->recursion, 0);
 
-	r = __mmu_notifier_register(&amn->mn, mm);
+	amn->mirror.ops = &amdgpu_hmm_mirror_ops[type];
+	r = hmm_mirror_register(&amn->mirror, mm);
 	if (r)
 		goto free_amn;
 
@@ -432,7 +408,7 @@ struct amdgpu_mn *amdgpu_mn_get(struct amdgpu_device *adev,
  * @bo: amdgpu buffer object
  * @addr: userptr addr we should monitor
  *
- * Registers an MMU notifier for the given BO at the specified address.
+ * Registers an HMM mirror for the given BO at the specified address.
  * Returns 0 on success, -ERRNO if anything goes wrong.
  */
 int amdgpu_mn_register(struct amdgpu_bo *bo, unsigned long addr)
@@ -488,11 +464,11 @@ int amdgpu_mn_register(struct amdgpu_bo *bo, unsigned long addr)
 }
 
 /**
- * amdgpu_mn_unregister - unregister a BO for notifier updates
+ * amdgpu_mn_unregister - unregister a BO for HMM mirror updates
  *
  * @bo: amdgpu buffer object
  *
- * Remove any registration of MMU notifier updates from the buffer object.
+ * Remove any registration of HMM mirror updates from the buffer object.
  */
 void amdgpu_mn_unregister(struct amdgpu_bo *bo)
 {
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.h
index eb0f432f78fe..0a51fd00021c 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.h
@@ -34,7 +34,7 @@ enum amdgpu_mn_type {
 	AMDGPU_MN_TYPE_HSA,
 };
 
-#if defined(CONFIG_MMU_NOTIFIER)
+#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,
-- 
2.17.1

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[PATCH 2/3] drm/amdkfd: avoid HMM change cause circular lock dependency v2

[Yang, Philip]

There is circular lock between gfx and kfd path with HMM change:
lock(dqm) -> bo::reserve -> amdgpu_mn_lock

To avoid this, move init/unint_mqd() out of lock(dqm), to remove nested
locking between mmap_sem and bo::reserve. The locking order
is: bo::reserve -> amdgpu_mn_lock(p->mn)

Change-Id: I2ec09a47571f6b4c8eaef93f22c0a600f5f70153
Signed-off-by: Philip Yang <Philip.Yang@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
---
 .../drm/amd/amdkfd/kfd_device_queue_manager.c | 32 ++++++++++---------
 1 file changed, 17 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
index 8372556b52eb..efe0d3c0215b 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
@@ -1156,21 +1156,17 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q,
 	int retval;
 	struct mqd_manager *mqd_mgr;
 
-	retval = 0;
-
-	dqm_lock(dqm);
-
 	if (dqm->total_queue_count >= max_num_of_queues_per_device) {
 		pr_warn("Can't create new usermode queue because %d queues were already created\n",
 				dqm->total_queue_count);
 		retval = -EPERM;
-		goto out_unlock;
+		goto out;
 	}
 
 	if (q->properties.type == KFD_QUEUE_TYPE_SDMA) {
 		retval = allocate_sdma_queue(dqm, &q->sdma_id);
 		if (retval)
-			goto out_unlock;
+			goto out;
 		q->properties.sdma_queue_id =
 			q->sdma_id / get_num_sdma_engines(dqm);
 		q->properties.sdma_engine_id =
@@ -1181,6 +1177,9 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q,
 	if (retval)
 		goto out_deallocate_sdma_queue;
 
+	/* Do init_mqd before dqm_lock(dqm) to avoid circular locking order:
+	 * lock(dqm) -> bo::reserve
+	 */
 	mqd_mgr = dqm->ops.get_mqd_manager(dqm,
 			get_mqd_type_from_queue_type(q->properties.type));
 
@@ -1188,6 +1187,7 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q,
 		retval = -ENOMEM;
 		goto out_deallocate_doorbell;
 	}
+
 	/*
 	 * Eviction state logic: we only mark active queues as evicted
 	 * to avoid the overhead of restoring inactive queues later
@@ -1196,9 +1196,7 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q,
 		q->properties.is_evicted = (q->properties.queue_size > 0 &&
 					    q->properties.queue_percent > 0 &&
 					    q->properties.queue_address != 0);
-
 	dqm->asic_ops.init_sdma_vm(dqm, q, qpd);
-
 	q->properties.tba_addr = qpd->tba_addr;
 	q->properties.tma_addr = qpd->tma_addr;
 	retval = mqd_mgr->init_mqd(mqd_mgr, &q->mqd, &q->mqd_mem_obj,
@@ -1206,6 +1204,8 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q,
 	if (retval)
 		goto out_deallocate_doorbell;
 
+	dqm_lock(dqm);
+
 	list_add(&q->list, &qpd->queues_list);
 	qpd->queue_count++;
 	if (q->properties.is_active) {
@@ -1233,9 +1233,7 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q,
 out_deallocate_sdma_queue:
 	if (q->properties.type == KFD_QUEUE_TYPE_SDMA)
 		deallocate_sdma_queue(dqm, q->sdma_id);
-out_unlock:
-	dqm_unlock(dqm);
-
+out:
 	return retval;
 }
 
@@ -1398,8 +1396,6 @@ static int destroy_queue_cpsch(struct device_queue_manager *dqm,
 			qpd->reset_wavefronts = true;
 	}
 
-	mqd_mgr->uninit_mqd(mqd_mgr, q->mqd, q->mqd_mem_obj);
-
 	/*
 	 * Unconditionally decrement this counter, regardless of the queue's
 	 * type
@@ -1410,6 +1406,9 @@ static int destroy_queue_cpsch(struct device_queue_manager *dqm,
 
 	dqm_unlock(dqm);
 
+	/* Do uninit_mqd after dqm_unlock(dqm) to avoid circular locking */
+	mqd_mgr->uninit_mqd(mqd_mgr, q->mqd, q->mqd_mem_obj);
+
 	return retval;
 
 failed:
@@ -1631,7 +1630,11 @@ static int process_termination_cpsch(struct device_queue_manager *dqm,
 		qpd->reset_wavefronts = false;
 	}
 
-	/* lastly, free mqd resources */
+	dqm_unlock(dqm);
+
+	/* Lastly, free mqd resources.
+	 * Do uninit_mqd() after dqm_unlock to avoid circular locking.
+	 */
 	list_for_each_entry_safe(q, next, &qpd->queues_list, list) {
 		mqd_mgr = dqm->ops.get_mqd_manager(dqm,
 			get_mqd_type_from_queue_type(q->properties.type));
@@ -1645,7 +1648,6 @@ static int process_termination_cpsch(struct device_queue_manager *dqm,
 	}
 
 out:
-	dqm_unlock(dqm);
 	return retval;
 }
 
-- 
2.17.1

_______________________________________________
amd-gfx mailing list
amd-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/amd-gfx

[PATCH 3/3] drm/amdgpu: replace get_user_pages with HMM address mirror helpers v8

[Yang, Philip]

Use HMM helper function hmm_vma_fault() to get physical pages backing
userptr and start CPU page table update track of those pages. Then use
hmm_vma_range_done() to check if those pages are updated before
amdgpu_cs_submit for gfx or before user queues are resumed for kfd.

If userptr pages are updated, for gfx, amdgpu_cs_ioctl will restart
from scratch, for kfd, restore worker is rescheduled to retry.

HMM simplify the CPU page table concurrent update check, so remove
guptasklock, mmu_invalidations, last_set_pages fields from
amdgpu_ttm_tt struct.

HMM does not pin the page (increase page ref count), so remove related
operations like release_pages(), put_page(), mark_page_dirty().

Change-Id: I2e8c0c6f0d8c21e5596a32d7fc91762778bc9e67
Signed-off-by: Philip Yang <Philip.Yang@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h    |   1 -
 .../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c  |  95 +++-------
 drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.h   |   2 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c        | 138 +++++---------
 drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c       |  14 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c        |  25 ++-
 drivers/gpu/drm/amd/amdgpu/amdgpu_mn.h        |   4 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c       | 178 +++++++-----------
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h       |   3 +-
 9 files changed, 182 insertions(+), 278 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
index 0b31a1859023..0e1711a75b68 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
@@ -61,7 +61,6 @@ struct kgd_mem {
 
 	atomic_t invalid;
 	struct amdkfd_process_info *process_info;
-	struct page **user_pages;
 
 	struct amdgpu_sync sync;
 
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
index d7b10d79f1de..ae2d838d31ea 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
@@ -582,28 +582,12 @@ static int init_user_pages(struct kgd_mem *mem, struct mm_struct *mm,
 		goto out;
 	}
 
-	/* If no restore worker is running concurrently, user_pages
-	 * should not be allocated
-	 */
-	WARN(mem->user_pages, "Leaking user_pages array");
-
-	mem->user_pages = kvmalloc_array(bo->tbo.ttm->num_pages,
-					   sizeof(struct page *),
-					   GFP_KERNEL | __GFP_ZERO);
-	if (!mem->user_pages) {
-		pr_err("%s: Failed to allocate pages array\n", __func__);
-		ret = -ENOMEM;
-		goto unregister_out;
-	}
-
-	ret = amdgpu_ttm_tt_get_user_pages(bo->tbo.ttm, mem->user_pages);
+	ret = amdgpu_ttm_tt_get_user_pages(bo->tbo.ttm, bo->tbo.ttm->pages);
 	if (ret) {
 		pr_err("%s: Failed to get user pages: %d\n", __func__, ret);
-		goto free_out;
+		goto unregister_out;
 	}
 
-	amdgpu_ttm_tt_set_user_pages(bo->tbo.ttm, mem->user_pages);
-
 	ret = amdgpu_bo_reserve(bo, true);
 	if (ret) {
 		pr_err("%s: Failed to reserve BO\n", __func__);
@@ -616,11 +600,7 @@ static int init_user_pages(struct kgd_mem *mem, struct mm_struct *mm,
 	amdgpu_bo_unreserve(bo);
 
 release_out:
-	if (ret)
-		release_pages(mem->user_pages, bo->tbo.ttm->num_pages);
-free_out:
-	kvfree(mem->user_pages);
-	mem->user_pages = NULL;
+	amdgpu_ttm_tt_get_user_pages_done(bo->tbo.ttm);
 unregister_out:
 	if (ret)
 		amdgpu_mn_unregister(bo);
@@ -679,7 +659,6 @@ static int reserve_bo_and_vm(struct kgd_mem *mem,
 	ctx->kfd_bo.priority = 0;
 	ctx->kfd_bo.tv.bo = &bo->tbo;
 	ctx->kfd_bo.tv.num_shared = 1;
-	ctx->kfd_bo.user_pages = NULL;
 	list_add(&ctx->kfd_bo.tv.head, &ctx->list);
 
 	amdgpu_vm_get_pd_bo(vm, &ctx->list, &ctx->vm_pd[0]);
@@ -743,7 +722,6 @@ static int reserve_bo_and_cond_vms(struct kgd_mem *mem,
 	ctx->kfd_bo.priority = 0;
 	ctx->kfd_bo.tv.bo = &bo->tbo;
 	ctx->kfd_bo.tv.num_shared = 1;
-	ctx->kfd_bo.user_pages = NULL;
 	list_add(&ctx->kfd_bo.tv.head, &ctx->list);
 
 	i = 0;
@@ -1371,15 +1349,6 @@ int amdgpu_amdkfd_gpuvm_free_memory_of_gpu(
 	list_del(&bo_list_entry->head);
 	mutex_unlock(&process_info->lock);
 
-	/* Free user pages if necessary */
-	if (mem->user_pages) {
-		pr_debug("%s: Freeing user_pages array\n", __func__);
-		if (mem->user_pages[0])
-			release_pages(mem->user_pages,
-					mem->bo->tbo.ttm->num_pages);
-		kvfree(mem->user_pages);
-	}
-
 	ret = reserve_bo_and_cond_vms(mem, NULL, BO_VM_ALL, &ctx);
 	if (unlikely(ret))
 		return ret;
@@ -1855,25 +1824,11 @@ static int update_invalid_user_pages(struct amdkfd_process_info *process_info,
 
 		bo = mem->bo;
 
-		if (!mem->user_pages) {
-			mem->user_pages =
-				kvmalloc_array(bo->tbo.ttm->num_pages,
-						 sizeof(struct page *),
-						 GFP_KERNEL | __GFP_ZERO);
-			if (!mem->user_pages) {
-				pr_err("%s: Failed to allocate pages array\n",
-				       __func__);
-				return -ENOMEM;
-			}
-		} else if (mem->user_pages[0]) {
-			release_pages(mem->user_pages, bo->tbo.ttm->num_pages);
-		}
-
 		/* Get updated user pages */
 		ret = amdgpu_ttm_tt_get_user_pages(bo->tbo.ttm,
-						   mem->user_pages);
+						   bo->tbo.ttm->pages);
 		if (ret) {
-			mem->user_pages[0] = NULL;
+			bo->tbo.ttm->pages[0] = NULL;
 			pr_info("%s: Failed to get user pages: %d\n",
 				__func__, ret);
 			/* Pretend it succeeded. It will fail later
@@ -1882,12 +1837,6 @@ static int update_invalid_user_pages(struct amdkfd_process_info *process_info,
 			 * stalled user mode queues.
 			 */
 		}
-
-		/* Mark the BO as valid unless it was invalidated
-		 * again concurrently
-		 */
-		if (atomic_cmpxchg(&mem->invalid, invalid, 0) != invalid)
-			return -EAGAIN;
 	}
 
 	return 0;
@@ -1917,7 +1866,8 @@ static int validate_invalid_user_pages(struct amdkfd_process_info *process_info)
 				     GFP_KERNEL);
 	if (!pd_bo_list_entries) {
 		pr_err("%s: Failed to allocate PD BO list entries\n", __func__);
-		return -ENOMEM;
+		ret = -ENOMEM;
+		goto out_no_mem;
 	}
 
 	INIT_LIST_HEAD(&resv_list);
@@ -1941,7 +1891,7 @@ static int validate_invalid_user_pages(struct amdkfd_process_info *process_info)
 	ret = ttm_eu_reserve_buffers(&ticket, &resv_list, false, &duplicates);
 	WARN(!list_empty(&duplicates), "Duplicates should be empty");
 	if (ret)
-		goto out;
+		goto out_free;
 
 	amdgpu_sync_create(&sync);
 
@@ -1967,10 +1917,8 @@ static int validate_invalid_user_pages(struct amdkfd_process_info *process_info)
 
 		bo = mem->bo;
 
-		/* Copy pages array and validate the BO if we got user pages */
-		if (mem->user_pages[0]) {
-			amdgpu_ttm_tt_set_user_pages(bo->tbo.ttm,
-						     mem->user_pages);
+		/* Validate the BO if we got user pages */
+		if (bo->tbo.ttm->pages[0]) {
 			amdgpu_bo_placement_from_domain(bo, mem->domain);
 			ret = ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
 			if (ret) {
@@ -1979,16 +1927,16 @@ static int validate_invalid_user_pages(struct amdkfd_process_info *process_info)
 			}
 		}
 
-		/* Validate succeeded, now the BO owns the pages, free
-		 * our copy of the pointer array. Put this BO back on
-		 * the userptr_valid_list. If we need to revalidate
-		 * it, we need to start from scratch.
-		 */
-		kvfree(mem->user_pages);
-		mem->user_pages = NULL;
 		list_move_tail(&mem->validate_list.head,
 			       &process_info->userptr_valid_list);
 
+		/* Stop HMM track the userptr update. We dont check the return
+		 * value for concurrent CPU page table update because we will
+		 * reschedule the restore worker if process_info->evicted_bos
+		 * is updated.
+		 */
+		amdgpu_ttm_tt_get_user_pages_done(bo->tbo.ttm);
+
 		/* Update mapping. If the BO was not validated
 		 * (because we couldn't get user pages), this will
 		 * clear the page table entries, which will result in
@@ -2022,8 +1970,15 @@ static int validate_invalid_user_pages(struct amdkfd_process_info *process_info)
 	ttm_eu_backoff_reservation(&ticket, &resv_list);
 	amdgpu_sync_wait(&sync, false);
 	amdgpu_sync_free(&sync);
-out:
+out_free:
 	kfree(pd_bo_list_entries);
+out_no_mem:
+	list_for_each_entry_safe(mem, tmp_mem,
+				 &process_info->userptr_inval_list,
+				 validate_list.head) {
+		bo = mem->bo;
+		amdgpu_ttm_tt_get_user_pages_done(bo->tbo.ttm);
+	}
 
 	return ret;
 }
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.h
index 7c5f5d1601e6..a130e766cbdb 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.h
@@ -36,7 +36,7 @@ struct amdgpu_bo_list_entry {
 	struct amdgpu_bo_va		*bo_va;
 	uint32_t			priority;
 	struct page			**user_pages;
-	int				user_invalidated;
+	bool				user_invalidated;
 };
 
 struct amdgpu_bo_list {
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
index 52a5e4fdc95b..545302d0955f 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
@@ -52,7 +52,6 @@ static int amdgpu_cs_user_fence_chunk(struct amdgpu_cs_parser *p,
 	p->uf_entry.tv.bo = &bo->tbo;
 	/* One for TTM and one for the CS job */
 	p->uf_entry.tv.num_shared = 2;
-	p->uf_entry.user_pages = NULL;
 
 	drm_gem_object_put_unlocked(gobj);
 
@@ -540,14 +539,14 @@ static int amdgpu_cs_list_validate(struct amdgpu_cs_parser *p,
 		if (usermm && usermm != current->mm)
 			return -EPERM;
 
-		/* Check if we have user pages and nobody bound the BO already */
-		if (amdgpu_ttm_tt_userptr_needs_pages(bo->tbo.ttm) &&
-		    lobj->user_pages) {
+		if (amdgpu_ttm_tt_is_userptr(bo->tbo.ttm) &&
+		    lobj->user_invalidated && lobj->user_pages) {
 			amdgpu_bo_placement_from_domain(bo,
 							AMDGPU_GEM_DOMAIN_CPU);
 			r = ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
 			if (r)
 				return r;
+
 			amdgpu_ttm_tt_set_user_pages(bo->tbo.ttm,
 						     lobj->user_pages);
 			binding_userptr = true;
@@ -578,7 +577,6 @@ static int amdgpu_cs_parser_bos(struct amdgpu_cs_parser *p,
 	struct amdgpu_bo *gds;
 	struct amdgpu_bo *gws;
 	struct amdgpu_bo *oa;
-	unsigned tries = 10;
 	int r;
 
 	INIT_LIST_HEAD(&p->validated);
@@ -614,79 +612,45 @@ static int amdgpu_cs_parser_bos(struct amdgpu_cs_parser *p,
 	if (p->uf_entry.tv.bo && !ttm_to_amdgpu_bo(p->uf_entry.tv.bo)->parent)
 		list_add(&p->uf_entry.tv.head, &p->validated);
 
-	while (1) {
-		struct list_head need_pages;
-
-		r = ttm_eu_reserve_buffers(&p->ticket, &p->validated, true,
-					   &duplicates);
-		if (unlikely(r != 0)) {
-			if (r != -ERESTARTSYS)
-				DRM_ERROR("ttm_eu_reserve_buffers failed.\n");
-			goto error_free_pages;
-		}
-
-		INIT_LIST_HEAD(&need_pages);
-		amdgpu_bo_list_for_each_userptr_entry(e, p->bo_list) {
-			struct amdgpu_bo *bo = ttm_to_amdgpu_bo(e->tv.bo);
-
-			if (amdgpu_ttm_tt_userptr_invalidated(bo->tbo.ttm,
-				 &e->user_invalidated) && e->user_pages) {
-
-				/* We acquired a page array, but somebody
-				 * invalidated it. Free it and try again
-				 */
-				release_pages(e->user_pages,
-					      bo->tbo.ttm->num_pages);
-				kvfree(e->user_pages);
-				e->user_pages = NULL;
-			}
-
-			if (amdgpu_ttm_tt_userptr_needs_pages(bo->tbo.ttm) &&
-			    !e->user_pages) {
-				list_del(&e->tv.head);
-				list_add(&e->tv.head, &need_pages);
-
-				amdgpu_bo_unreserve(bo);
-			}
+	/* Get userptr backing pages. If pages are updated after registered
+	 * in amdgpu_gem_userptr_ioctl(), amdgpu_cs_list_validate() will do
+	 * amdgpu_ttm_backend_bind() to flush and invalidate new pages
+	 */
+	amdgpu_bo_list_for_each_userptr_entry(e, p->bo_list) {
+		struct amdgpu_bo *bo = ttm_to_amdgpu_bo(e->tv.bo);
+		bool userpage_invalidated = false;
+		int i;
+
+		e->user_pages = kvmalloc_array(bo->tbo.ttm->num_pages,
+					sizeof(struct page *),
+					GFP_KERNEL | __GFP_ZERO);
+		if (!e->user_pages) {
+			DRM_ERROR("calloc failure\n");
+			return -ENOMEM;
 		}
 
-		if (list_empty(&need_pages))
-			break;
-
-		/* Unreserve everything again. */
-		ttm_eu_backoff_reservation(&p->ticket, &p->validated);
-
-		/* We tried too many times, just abort */
-		if (!--tries) {
-			r = -EDEADLK;
-			DRM_ERROR("deadlock in %s\n", __func__);
-			goto error_free_pages;
+		r = amdgpu_ttm_tt_get_user_pages(bo->tbo.ttm, e->user_pages);
+		if (r) {
+			kvfree(e->user_pages);
+			e->user_pages = NULL;
+			return r;
 		}
 
-		/* Fill the page arrays for all userptrs. */
-		list_for_each_entry(e, &need_pages, tv.head) {
-			struct ttm_tt *ttm = e->tv.bo->ttm;
-
-			e->user_pages = kvmalloc_array(ttm->num_pages,
-							 sizeof(struct page*),
-							 GFP_KERNEL | __GFP_ZERO);
-			if (!e->user_pages) {
-				r = -ENOMEM;
-				DRM_ERROR("calloc failure in %s\n", __func__);
-				goto error_free_pages;
-			}
-
-			r = amdgpu_ttm_tt_get_user_pages(ttm, e->user_pages);
-			if (r) {
-				DRM_ERROR("amdgpu_ttm_tt_get_user_pages failed.\n");
-				kvfree(e->user_pages);
-				e->user_pages = NULL;
-				goto error_free_pages;
+		for (i = 0; i < bo->tbo.ttm->num_pages; i++) {
+			if (bo->tbo.ttm->pages[i] != e->user_pages[i]) {
+				userpage_invalidated = true;
+				break;
 			}
 		}
+		e->user_invalidated = userpage_invalidated;
+	}
 
-		/* And try again. */
-		list_splice(&need_pages, &p->validated);
+	r = ttm_eu_reserve_buffers(&p->ticket, &p->validated, true,
+				   &duplicates);
+	if (unlikely(r != 0)) {
+		if (r != -ERESTARTSYS)
+			DRM_ERROR("ttm_eu_reserve_buffers failed.\n");
+		goto out;
 	}
 
 	amdgpu_cs_get_threshold_for_moves(p->adev, &p->bytes_moved_threshold,
@@ -755,17 +719,7 @@ static int amdgpu_cs_parser_bos(struct amdgpu_cs_parser *p,
 error_validate:
 	if (r)
 		ttm_eu_backoff_reservation(&p->ticket, &p->validated);
-
-error_free_pages:
-
-	amdgpu_bo_list_for_each_userptr_entry(e, p->bo_list) {
-		if (!e->user_pages)
-			continue;
-
-		release_pages(e->user_pages, e->tv.bo->ttm->num_pages);
-		kvfree(e->user_pages);
-	}
-
+out:
 	return r;
 }
 
@@ -1224,7 +1178,6 @@ static int amdgpu_cs_submit(struct amdgpu_cs_parser *p,
 	struct amdgpu_bo_list_entry *e;
 	struct amdgpu_job *job;
 	uint64_t seq;
-
 	int r;
 
 	job = p->job;
@@ -1234,15 +1187,23 @@ 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 */
+	/* 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.
+	 */
 	amdgpu_mn_lock(p->mn);
+
+	/* If userptr are invalidated after amdgpu_cs_parser_bos(), return
+	 * -EAGAIN, drmIoctl in libdrm will restart the amdgpu_cs_ioctl.
+	 */
 	amdgpu_bo_list_for_each_userptr_entry(e, p->bo_list) {
 		struct amdgpu_bo *bo = ttm_to_amdgpu_bo(e->tv.bo);
 
-		if (amdgpu_ttm_tt_userptr_needs_pages(bo->tbo.ttm)) {
-			r = -ERESTARTSYS;
-			goto error_abort;
-		}
+		r |= !amdgpu_ttm_tt_get_user_pages_done(bo->tbo.ttm);
+	}
+	if (r) {
+		r = -EAGAIN;
+		goto error_abort;
 	}
 
 	job->owner = p->filp;
@@ -1338,6 +1299,7 @@ int amdgpu_cs_ioctl(struct drm_device *dev, void *data, struct drm_file *filp)
 
 out:
 	amdgpu_cs_parser_fini(&parser, r, reserved_buffers);
+
 	return r;
 }
 
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
index d21dd2f369da..555285e329ed 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
@@ -329,26 +329,24 @@ int amdgpu_gem_userptr_ioctl(struct drm_device *dev, void *data,
 
 		r = amdgpu_bo_reserve(bo, true);
 		if (r)
-			goto free_pages;
+			goto user_pages_done;
 
 		amdgpu_bo_placement_from_domain(bo, AMDGPU_GEM_DOMAIN_GTT);
 		r = ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
 		amdgpu_bo_unreserve(bo);
 		if (r)
-			goto free_pages;
+			goto user_pages_done;
 	}
 
 	r = drm_gem_handle_create(filp, gobj, &handle);
-	/* drop reference from allocate - handle holds it now */
-	drm_gem_object_put_unlocked(gobj);
 	if (r)
-		return r;
+		goto user_pages_done;
 
 	args->handle = handle;
-	return 0;
 
-free_pages:
-	release_pages(bo->tbo.ttm->pages, bo->tbo.ttm->num_pages);
+user_pages_done:
+	if (args->flags & AMDGPU_GEM_USERPTR_VALIDATE)
+		amdgpu_ttm_tt_get_user_pages_done(bo->tbo.ttm);
 
 release_object:
 	drm_gem_object_put_unlocked(gobj);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
index e356867d2308..fa2516016c43 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
@@ -222,8 +222,6 @@ static void amdgpu_mn_invalidate_node(struct amdgpu_mn_node *node,
 			true, false, MAX_SCHEDULE_TIMEOUT);
 		if (r <= 0)
 			DRM_ERROR("(%ld) failed to wait for user bo\n", r);
-
-		amdgpu_ttm_tt_mark_user_pages(bo->tbo.ttm);
 	}
 }
 
@@ -504,3 +502,26 @@ void amdgpu_mn_unregister(struct amdgpu_bo *bo)
 	mutex_unlock(&adev->mn_lock);
 }
 
+/* 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;
+		range->pfns = NULL;
+		INIT_LIST_HEAD(&range->list);
+	}
+}
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.h
index 0a51fd00021c..4803e216e174 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.h
@@ -25,9 +25,10 @@
 #define __AMDGPU_MN_H__
 
 /*
- * MMU Notifier
+ * HMM mirror
  */
 struct amdgpu_mn;
+struct hmm_range;
 
 enum amdgpu_mn_type {
 	AMDGPU_MN_TYPE_GFX,
@@ -41,6 +42,7 @@ 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) {}
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index 73e71e61dc99..1e675048f790 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -43,6 +43,7 @@
 #include <linux/pagemap.h>
 #include <linux/debugfs.h>
 #include <linux/iommu.h>
+#include <linux/hmm.h>
 #include "amdgpu.h"
 #include "amdgpu_object.h"
 #include "amdgpu_trace.h"
@@ -705,98 +706,102 @@ static unsigned long amdgpu_ttm_io_mem_pfn(struct ttm_buffer_object *bo,
 /*
  * TTM backend functions.
  */
-struct amdgpu_ttm_gup_task_list {
-	struct list_head	list;
-	struct task_struct	*task;
-};
-
 struct amdgpu_ttm_tt {
 	struct ttm_dma_tt	ttm;
 	u64			offset;
 	uint64_t		userptr;
 	struct task_struct	*usertask;
 	uint32_t		userflags;
-	spinlock_t              guptasklock;
-	struct list_head        guptasks;
-	atomic_t		mmu_invalidations;
-	uint32_t		last_set_pages;
+	struct hmm_range	range;
 };
 
 /**
- * amdgpu_ttm_tt_get_user_pages - Pin pages of memory pointed to by a USERPTR
- * pointer to memory
+ * amdgpu_ttm_tt_get_user_pages - get device accessible pages that back user
+ * memory and start HMM tracking CPU page table update
  *
- * 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.
+ * Calling function must call amdgpu_ttm_tt_userptr_range_done() once and only
+ * once afterwards to stop HMM tracking
  */
 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 int flags = 0;
-	unsigned pinned = 0;
-	int r;
+	unsigned long end = gtt->userptr + ttm->num_pages * PAGE_SIZE;
+	struct hmm_range *range = &gtt->range;
+	int r = 0, i;
 
 	if (!mm) /* Happens during process shutdown */
 		return -ESRCH;
 
-	if (!(gtt->userflags & AMDGPU_GEM_USERPTR_READONLY))
-		flags |= FOLL_WRITE;
+	amdgpu_hmm_init_range(range);
 
 	down_read(&mm->mmap_sem);
 
-	if (gtt->userflags & AMDGPU_GEM_USERPTR_ANONONLY) {
-		/*
-		 * check that we only use anonymous memory to prevent problems
-		 * with writeback
-		 */
-		unsigned long end = gtt->userptr + ttm->num_pages * PAGE_SIZE;
-		struct vm_area_struct *vma;
+	range->vma = find_vma(mm, gtt->userptr);
+	if (!range_in_vma(range->vma, gtt->userptr, end))
+		r = -EFAULT;
+	else if ((gtt->userflags & AMDGPU_GEM_USERPTR_ANONONLY) &&
+		range->vma->vm_file)
+		r = -EPERM;
+	if (r)
+		goto out;
 
-		vma = find_vma(mm, gtt->userptr);
-		if (!vma || vma->vm_file || vma->vm_end < end) {
-			up_read(&mm->mmap_sem);
-			return -EPERM;
-		}
+	range->pfns = kvmalloc_array(ttm->num_pages, sizeof(uint64_t),
+				     GFP_KERNEL);
+	if (range->pfns == NULL) {
+		r = -ENOMEM;
+		goto out;
 	}
+	range->start = gtt->userptr;
+	range->end = end;
 
-	/* loop enough times using contiguous pages of memory */
-	do {
-		unsigned num_pages = ttm->num_pages - pinned;
-		uint64_t userptr = gtt->userptr + pinned * PAGE_SIZE;
-		struct page **p = pages + pinned;
-		struct amdgpu_ttm_gup_task_list guptask;
+	range->pfns[0] = range->flags[HMM_PFN_VALID];
+	range->pfns[0] |= amdgpu_ttm_tt_is_readonly(ttm) ?
+				0 : range->flags[HMM_PFN_WRITE];
+	for (i = 1; i < ttm->num_pages; i++)
+		range->pfns[i] = range->pfns[0];
 
-		guptask.task = current;
-		spin_lock(&gtt->guptasklock);
-		list_add(&guptask.list, &gtt->guptasks);
-		spin_unlock(&gtt->guptasklock);
+	/* This may trigger page table update */
+	r = hmm_vma_fault(range, true);
+	if (r)
+		goto out_free_pfns;
 
-		if (mm == current->mm)
-			r = get_user_pages(userptr, num_pages, flags, p, NULL);
-		else
-			r = get_user_pages_remote(gtt->usertask,
-					mm, userptr, num_pages,
-					flags, p, NULL, NULL);
+	up_read(&mm->mmap_sem);
 
-		spin_lock(&gtt->guptasklock);
-		list_del(&guptask.list);
-		spin_unlock(&gtt->guptasklock);
+	for (i = 0; i < ttm->num_pages; i++)
+		pages[i] = hmm_pfn_to_page(range, range->pfns[i]);
 
-		if (r < 0)
-			goto release_pages;
+	return 0;
 
-		pinned += r;
+out_free_pfns:
+	kvfree(range->pfns);
+	range->pfns = NULL;
+out:
+	up_read(&mm->mmap_sem);
+	return r;
+}
 
-	} while (pinned < ttm->num_pages);
+/**
+ * amdgpu_ttm_tt_userptr_range_done - stop HMM track the CPU page table change
+ * Check if the pages backing this ttm range have been invalidated
+ *
+ * Returns: true if pages are still valid
+ */
+bool amdgpu_ttm_tt_get_user_pages_done(struct ttm_tt *ttm)
+{
+	struct amdgpu_ttm_tt *gtt = (void *)ttm;
+	bool r = false;
 
-	up_read(&mm->mmap_sem);
-	return 0;
+	if (!gtt || !gtt->userptr)
+		return false;
+
+	WARN_ONCE(!gtt->range.pfns, "No user pages to check\n");
+	if (gtt->range.pfns) {
+		r = hmm_vma_range_done(&gtt->range);
+		kvfree(gtt->range.pfns);
+		gtt->range.pfns = NULL;
+	}
 
-release_pages:
-	release_pages(pages, pinned);
-	up_read(&mm->mmap_sem);
 	return r;
 }
 
@@ -809,16 +814,10 @@ int amdgpu_ttm_tt_get_user_pages(struct ttm_tt *ttm, struct page **pages)
  */
 void amdgpu_ttm_tt_set_user_pages(struct ttm_tt *ttm, struct page **pages)
 {
-	struct amdgpu_ttm_tt *gtt = (void *)ttm;
 	unsigned i;
 
-	gtt->last_set_pages = atomic_read(&gtt->mmu_invalidations);
-	for (i = 0; i < ttm->num_pages; ++i) {
-		if (ttm->pages[i])
-			put_page(ttm->pages[i]);
-
+	for (i = 0; i < ttm->num_pages; ++i)
 		ttm->pages[i] = pages ? pages[i] : NULL;
-	}
 }
 
 /**
@@ -903,10 +902,11 @@ static void amdgpu_ttm_tt_unpin_userptr(struct ttm_tt *ttm)
 	/* 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);
+
+	if (gtt->range.pfns &&
+	    ttm->pages[0] == hmm_pfn_to_page(&gtt->range, gtt->range.pfns[0]))
+		WARN_ONCE(1, "Missing get_user_page_done\n");
 }
 
 int amdgpu_ttm_gart_bind(struct amdgpu_device *adev,
@@ -1256,11 +1256,6 @@ int amdgpu_ttm_tt_set_userptr(struct ttm_tt *ttm, uint64_t addr,
 	gtt->usertask = current->group_leader;
 	get_task_struct(gtt->usertask);
 
-	spin_lock_init(&gtt->guptasklock);
-	INIT_LIST_HEAD(&gtt->guptasks);
-	atomic_set(&gtt->mmu_invalidations, 0);
-	gtt->last_set_pages = 0;
-
 	return 0;
 }
 
@@ -1289,7 +1284,6 @@ bool amdgpu_ttm_tt_affect_userptr(struct ttm_tt *ttm, unsigned long start,
 				  unsigned long end)
 {
 	struct amdgpu_ttm_tt *gtt = (void *)ttm;
-	struct amdgpu_ttm_gup_task_list *entry;
 	unsigned long size;
 
 	if (gtt == NULL || !gtt->userptr)
@@ -1302,48 +1296,20 @@ bool amdgpu_ttm_tt_affect_userptr(struct ttm_tt *ttm, unsigned long start,
 	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(&gtt->guptasklock);
-	list_for_each_entry(entry, &gtt->guptasks, list) {
-		if (entry->task == current) {
-			spin_unlock(&gtt->guptasklock);
-			return false;
-		}
-	}
-	spin_unlock(&gtt->guptasklock);
-
-	atomic_inc(&gtt->mmu_invalidations);
-
 	return true;
 }
 
 /**
- * amdgpu_ttm_tt_userptr_invalidated - Has the ttm_tt object been invalidated?
+ * amdgpu_ttm_tt_is_userptr - Have the pages backing by userptr?
  */
-bool amdgpu_ttm_tt_userptr_invalidated(struct ttm_tt *ttm,
-				       int *last_invalidated)
-{
-	struct amdgpu_ttm_tt *gtt = (void *)ttm;
-	int prev_invalidated = *last_invalidated;
-
-	*last_invalidated = atomic_read(&gtt->mmu_invalidations);
-	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)
+bool amdgpu_ttm_tt_is_userptr(struct ttm_tt *ttm)
 {
 	struct amdgpu_ttm_tt *gtt = (void *)ttm;
 
 	if (gtt == NULL || !gtt->userptr)
 		return false;
 
-	return atomic_read(&gtt->mmu_invalidations) != gtt->last_set_pages;
+	return true;
 }
 
 /**
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
index b5b2d101f7db..8988c87fff9d 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
@@ -102,6 +102,7 @@ int amdgpu_ttm_alloc_gart(struct ttm_buffer_object *bo);
 int amdgpu_ttm_recover_gart(struct ttm_buffer_object *tbo);
 
 int amdgpu_ttm_tt_get_user_pages(struct ttm_tt *ttm, struct page **pages);
+bool amdgpu_ttm_tt_get_user_pages_done(struct ttm_tt *ttm);
 void amdgpu_ttm_tt_set_user_pages(struct ttm_tt *ttm, struct page **pages);
 void amdgpu_ttm_tt_mark_user_pages(struct ttm_tt *ttm);
 int amdgpu_ttm_tt_set_userptr(struct ttm_tt *ttm, uint64_t addr,
@@ -112,7 +113,7 @@ bool amdgpu_ttm_tt_affect_userptr(struct ttm_tt *ttm, unsigned long start,
 				  unsigned long end);
 bool amdgpu_ttm_tt_userptr_invalidated(struct ttm_tt *ttm,
 				       int *last_invalidated);
-bool amdgpu_ttm_tt_userptr_needs_pages(struct ttm_tt *ttm);
+bool amdgpu_ttm_tt_is_userptr(struct ttm_tt *ttm);
 bool amdgpu_ttm_tt_is_readonly(struct ttm_tt *ttm);
 uint64_t amdgpu_ttm_tt_pde_flags(struct ttm_tt *ttm, struct ttm_mem_reg *mem);
 uint64_t amdgpu_ttm_tt_pte_flags(struct amdgpu_device *adev, struct ttm_tt *ttm,
-- 
2.17.1

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Re: [PATCH 2/3] drm/amdkfd: avoid HMM change cause circular lock dependency v2

[Christian König]

Am 04.02.19 um 19:23 schrieb Yang, Philip:
> There is circular lock between gfx and kfd path with HMM change:
> lock(dqm) -> bo::reserve -> amdgpu_mn_lock
>
> To avoid this, move init/unint_mqd() out of lock(dqm), to remove nested
> locking between mmap_sem and bo::reserve. The locking order
> is: bo::reserve -> amdgpu_mn_lock(p->mn)

In general this sounds correct to me, but apart from that I don't know 
the code well enough to fully judge.

>
> Change-Id: I2ec09a47571f6b4c8eaef93f22c0a600f5f70153
> Signed-off-by: Philip Yang <Philip.Yang@amd.com>

Acked-by: Christian König <christian.koenig@amd.com>

> ---
>   .../drm/amd/amdkfd/kfd_device_queue_manager.c | 32 ++++++++++---------
>   1 file changed, 17 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
> index 8372556b52eb..efe0d3c0215b 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
> @@ -1156,21 +1156,17 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q,
>   	int retval;
>   	struct mqd_manager *mqd_mgr;
>   
> -	retval = 0;
> -
> -	dqm_lock(dqm);
> -
>   	if (dqm->total_queue_count >= max_num_of_queues_per_device) {
>   		pr_warn("Can't create new usermode queue because %d queues were already created\n",
>   				dqm->total_queue_count);
>   		retval = -EPERM;
> -		goto out_unlock;
> +		goto out;
>   	}
>   
>   	if (q->properties.type == KFD_QUEUE_TYPE_SDMA) {
>   		retval = allocate_sdma_queue(dqm, &q->sdma_id);
>   		if (retval)
> -			goto out_unlock;
> +			goto out;
>   		q->properties.sdma_queue_id =
>   			q->sdma_id / get_num_sdma_engines(dqm);
>   		q->properties.sdma_engine_id =
> @@ -1181,6 +1177,9 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q,
>   	if (retval)
>   		goto out_deallocate_sdma_queue;
>   
> +	/* Do init_mqd before dqm_lock(dqm) to avoid circular locking order:
> +	 * lock(dqm) -> bo::reserve
> +	 */
>   	mqd_mgr = dqm->ops.get_mqd_manager(dqm,
>   			get_mqd_type_from_queue_type(q->properties.type));
>   
> @@ -1188,6 +1187,7 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q,
>   		retval = -ENOMEM;
>   		goto out_deallocate_doorbell;
>   	}
> +
>   	/*
>   	 * Eviction state logic: we only mark active queues as evicted
>   	 * to avoid the overhead of restoring inactive queues later
> @@ -1196,9 +1196,7 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q,
>   		q->properties.is_evicted = (q->properties.queue_size > 0 &&
>   					    q->properties.queue_percent > 0 &&
>   					    q->properties.queue_address != 0);
> -
>   	dqm->asic_ops.init_sdma_vm(dqm, q, qpd);
> -
>   	q->properties.tba_addr = qpd->tba_addr;
>   	q->properties.tma_addr = qpd->tma_addr;
>   	retval = mqd_mgr->init_mqd(mqd_mgr, &q->mqd, &q->mqd_mem_obj,
> @@ -1206,6 +1204,8 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q,
>   	if (retval)
>   		goto out_deallocate_doorbell;
>   
> +	dqm_lock(dqm);
> +
>   	list_add(&q->list, &qpd->queues_list);
>   	qpd->queue_count++;
>   	if (q->properties.is_active) {
> @@ -1233,9 +1233,7 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q,
>   out_deallocate_sdma_queue:
>   	if (q->properties.type == KFD_QUEUE_TYPE_SDMA)
>   		deallocate_sdma_queue(dqm, q->sdma_id);
> -out_unlock:
> -	dqm_unlock(dqm);
> -
> +out:
>   	return retval;
>   }
>   
> @@ -1398,8 +1396,6 @@ static int destroy_queue_cpsch(struct device_queue_manager *dqm,
>   			qpd->reset_wavefronts = true;
>   	}
>   
> -	mqd_mgr->uninit_mqd(mqd_mgr, q->mqd, q->mqd_mem_obj);
> -
>   	/*
>   	 * Unconditionally decrement this counter, regardless of the queue's
>   	 * type
> @@ -1410,6 +1406,9 @@ static int destroy_queue_cpsch(struct device_queue_manager *dqm,
>   
>   	dqm_unlock(dqm);
>   
> +	/* Do uninit_mqd after dqm_unlock(dqm) to avoid circular locking */
> +	mqd_mgr->uninit_mqd(mqd_mgr, q->mqd, q->mqd_mem_obj);
> +
>   	return retval;
>   
>   failed:
> @@ -1631,7 +1630,11 @@ static int process_termination_cpsch(struct device_queue_manager *dqm,
>   		qpd->reset_wavefronts = false;
>   	}
>   
> -	/* lastly, free mqd resources */
> +	dqm_unlock(dqm);
> +
> +	/* Lastly, free mqd resources.
> +	 * Do uninit_mqd() after dqm_unlock to avoid circular locking.
> +	 */
>   	list_for_each_entry_safe(q, next, &qpd->queues_list, list) {
>   		mqd_mgr = dqm->ops.get_mqd_manager(dqm,
>   			get_mqd_type_from_queue_type(q->properties.type));
> @@ -1645,7 +1648,6 @@ static int process_termination_cpsch(struct device_queue_manager *dqm,
>   	}
>   
>   out:
> -	dqm_unlock(dqm);
>   	return retval;
>   }
>   

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[PATCH 2/3] drm/amdkfd: avoid HMM change cause circular lock dependency v2

[Yang, Philip]

There is circular lock between gfx and kfd path with HMM change:
lock(dqm) -> bo::reserve -> amdgpu_mn_lock

To avoid this, move init/unint_mqd() out of lock(dqm), to remove nested
locking between mmap_sem and bo::reserve. The locking order
is: bo::reserve -> amdgpu_mn_lock(p->mn)

Change-Id: I2ec09a47571f6b4c8eaef93f22c0a600f5f70153
Signed-off-by: Philip Yang <Philip.Yang@amd.com>
---
 .../drm/amd/amdkfd/kfd_device_queue_manager.c | 32 ++++++++++---------
 1 file changed, 17 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
index 8372556b52eb..efe0d3c0215b 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
@@ -1156,21 +1156,17 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q,
 	int retval;
 	struct mqd_manager *mqd_mgr;
 
-	retval = 0;
-
-	dqm_lock(dqm);
-
 	if (dqm->total_queue_count >= max_num_of_queues_per_device) {
 		pr_warn("Can't create new usermode queue because %d queues were already created\n",
 				dqm->total_queue_count);
 		retval = -EPERM;
-		goto out_unlock;
+		goto out;
 	}
 
 	if (q->properties.type == KFD_QUEUE_TYPE_SDMA) {
 		retval = allocate_sdma_queue(dqm, &q->sdma_id);
 		if (retval)
-			goto out_unlock;
+			goto out;
 		q->properties.sdma_queue_id =
 			q->sdma_id / get_num_sdma_engines(dqm);
 		q->properties.sdma_engine_id =
@@ -1181,6 +1177,9 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q,
 	if (retval)
 		goto out_deallocate_sdma_queue;
 
+	/* Do init_mqd before dqm_lock(dqm) to avoid circular locking order:
+	 * lock(dqm) -> bo::reserve
+	 */
 	mqd_mgr = dqm->ops.get_mqd_manager(dqm,
 			get_mqd_type_from_queue_type(q->properties.type));
 
@@ -1188,6 +1187,7 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q,
 		retval = -ENOMEM;
 		goto out_deallocate_doorbell;
 	}
+
 	/*
 	 * Eviction state logic: we only mark active queues as evicted
 	 * to avoid the overhead of restoring inactive queues later
@@ -1196,9 +1196,7 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q,
 		q->properties.is_evicted = (q->properties.queue_size > 0 &&
 					    q->properties.queue_percent > 0 &&
 					    q->properties.queue_address != 0);
-
 	dqm->asic_ops.init_sdma_vm(dqm, q, qpd);
-
 	q->properties.tba_addr = qpd->tba_addr;
 	q->properties.tma_addr = qpd->tma_addr;
 	retval = mqd_mgr->init_mqd(mqd_mgr, &q->mqd, &q->mqd_mem_obj,
@@ -1206,6 +1204,8 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q,
 	if (retval)
 		goto out_deallocate_doorbell;
 
+	dqm_lock(dqm);
+
 	list_add(&q->list, &qpd->queues_list);
 	qpd->queue_count++;
 	if (q->properties.is_active) {
@@ -1233,9 +1233,7 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q,
 out_deallocate_sdma_queue:
 	if (q->properties.type == KFD_QUEUE_TYPE_SDMA)
 		deallocate_sdma_queue(dqm, q->sdma_id);
-out_unlock:
-	dqm_unlock(dqm);
-
+out:
 	return retval;
 }
 
@@ -1398,8 +1396,6 @@ static int destroy_queue_cpsch(struct device_queue_manager *dqm,
 			qpd->reset_wavefronts = true;
 	}
 
-	mqd_mgr->uninit_mqd(mqd_mgr, q->mqd, q->mqd_mem_obj);
-
 	/*
 	 * Unconditionally decrement this counter, regardless of the queue's
 	 * type
@@ -1410,6 +1406,9 @@ static int destroy_queue_cpsch(struct device_queue_manager *dqm,
 
 	dqm_unlock(dqm);
 
+	/* Do uninit_mqd after dqm_unlock(dqm) to avoid circular locking */
+	mqd_mgr->uninit_mqd(mqd_mgr, q->mqd, q->mqd_mem_obj);
+
 	return retval;
 
 failed:
@@ -1631,7 +1630,11 @@ static int process_termination_cpsch(struct device_queue_manager *dqm,
 		qpd->reset_wavefronts = false;
 	}
 
-	/* lastly, free mqd resources */
+	dqm_unlock(dqm);
+
+	/* Lastly, free mqd resources.
+	 * Do uninit_mqd() after dqm_unlock to avoid circular locking.
+	 */
 	list_for_each_entry_safe(q, next, &qpd->queues_list, list) {
 		mqd_mgr = dqm->ops.get_mqd_manager(dqm,
 			get_mqd_type_from_queue_type(q->properties.type));
@@ -1645,7 +1648,6 @@ static int process_termination_cpsch(struct device_queue_manager *dqm,
 	}
 
 out:
-	dqm_unlock(dqm);
 	return retval;
 }
 
-- 
2.17.1

_______________________________________________
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amd-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/amd-gfx

[PATCH 2/3] drm/amdkfd: avoid HMM change cause circular lock dependency v2

[Yang, Philip]

There is circular lock between gfx and kfd path with HMM change:
lock(dqm) -> bo::reserve -> amdgpu_mn_lock

To avoid this, move init/unint_mqd() out of lock(dqm), to remove nested
locking between mmap_sem and bo::reserve. The locking order
is: bo::reserve -> amdgpu_mn_lock(p->mn)

Change-Id: I2ec09a47571f6b4c8eaef93f22c0a600f5f70153
Signed-off-by: Philip Yang <Philip.Yang@amd.com>
---
 .../drm/amd/amdkfd/kfd_device_queue_manager.c | 32 ++++++++++---------
 1 file changed, 17 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
index 8372556b52eb..efe0d3c0215b 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
@@ -1156,21 +1156,17 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q,
 	int retval;
 	struct mqd_manager *mqd_mgr;
 
-	retval = 0;
-
-	dqm_lock(dqm);
-
 	if (dqm->total_queue_count >= max_num_of_queues_per_device) {
 		pr_warn("Can't create new usermode queue because %d queues were already created\n",
 				dqm->total_queue_count);
 		retval = -EPERM;
-		goto out_unlock;
+		goto out;
 	}
 
 	if (q->properties.type == KFD_QUEUE_TYPE_SDMA) {
 		retval = allocate_sdma_queue(dqm, &q->sdma_id);
 		if (retval)
-			goto out_unlock;
+			goto out;
 		q->properties.sdma_queue_id =
 			q->sdma_id / get_num_sdma_engines(dqm);
 		q->properties.sdma_engine_id =
@@ -1181,6 +1177,9 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q,
 	if (retval)
 		goto out_deallocate_sdma_queue;
 
+	/* Do init_mqd before dqm_lock(dqm) to avoid circular locking order:
+	 * lock(dqm) -> bo::reserve
+	 */
 	mqd_mgr = dqm->ops.get_mqd_manager(dqm,
 			get_mqd_type_from_queue_type(q->properties.type));
 
@@ -1188,6 +1187,7 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q,
 		retval = -ENOMEM;
 		goto out_deallocate_doorbell;
 	}
+
 	/*
 	 * Eviction state logic: we only mark active queues as evicted
 	 * to avoid the overhead of restoring inactive queues later
@@ -1196,9 +1196,7 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q,
 		q->properties.is_evicted = (q->properties.queue_size > 0 &&
 					    q->properties.queue_percent > 0 &&
 					    q->properties.queue_address != 0);
-
 	dqm->asic_ops.init_sdma_vm(dqm, q, qpd);
-
 	q->properties.tba_addr = qpd->tba_addr;
 	q->properties.tma_addr = qpd->tma_addr;
 	retval = mqd_mgr->init_mqd(mqd_mgr, &q->mqd, &q->mqd_mem_obj,
@@ -1206,6 +1204,8 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q,
 	if (retval)
 		goto out_deallocate_doorbell;
 
+	dqm_lock(dqm);
+
 	list_add(&q->list, &qpd->queues_list);
 	qpd->queue_count++;
 	if (q->properties.is_active) {
@@ -1233,9 +1233,7 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q,
 out_deallocate_sdma_queue:
 	if (q->properties.type == KFD_QUEUE_TYPE_SDMA)
 		deallocate_sdma_queue(dqm, q->sdma_id);
-out_unlock:
-	dqm_unlock(dqm);
-
+out:
 	return retval;
 }
 
@@ -1398,8 +1396,6 @@ static int destroy_queue_cpsch(struct device_queue_manager *dqm,
 			qpd->reset_wavefronts = true;
 	}
 
-	mqd_mgr->uninit_mqd(mqd_mgr, q->mqd, q->mqd_mem_obj);
-
 	/*
 	 * Unconditionally decrement this counter, regardless of the queue's
 	 * type
@@ -1410,6 +1406,9 @@ static int destroy_queue_cpsch(struct device_queue_manager *dqm,
 
 	dqm_unlock(dqm);
 
+	/* Do uninit_mqd after dqm_unlock(dqm) to avoid circular locking */
+	mqd_mgr->uninit_mqd(mqd_mgr, q->mqd, q->mqd_mem_obj);
+
 	return retval;
 
 failed:
@@ -1631,7 +1630,11 @@ static int process_termination_cpsch(struct device_queue_manager *dqm,
 		qpd->reset_wavefronts = false;
 	}
 
-	/* lastly, free mqd resources */
+	dqm_unlock(dqm);
+
+	/* Lastly, free mqd resources.
+	 * Do uninit_mqd() after dqm_unlock to avoid circular locking.
+	 */
 	list_for_each_entry_safe(q, next, &qpd->queues_list, list) {
 		mqd_mgr = dqm->ops.get_mqd_manager(dqm,
 			get_mqd_type_from_queue_type(q->properties.type));
@@ -1645,7 +1648,6 @@ static int process_termination_cpsch(struct device_queue_manager *dqm,
 	}
 
 out:
-	dqm_unlock(dqm);
 	return retval;
 }
 
-- 
2.17.1

_______________________________________________
amd-gfx mailing list
amd-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/amd-gfx

[PATCH 2/3] drm/amdkfd: avoid HMM change cause circular lock dependency v2

[Yang, Philip]

There is circular lock between gfx and kfd path with HMM change:
lock(dqm) -> bo::reserve -> amdgpu_mn_lock

To avoid this, move init/unint_mqd() out of lock(dqm), to remove nested
locking between mmap_sem and bo::reserve. The locking order
is: bo::reserve -> amdgpu_mn_lock(p->mn)

Change-Id: I2ec09a47571f6b4c8eaef93f22c0a600f5f70153
Signed-off-by: Philip Yang <Philip.Yang@amd.com>
---
 .../drm/amd/amdkfd/kfd_device_queue_manager.c | 32 ++++++++++---------
 1 file changed, 17 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
index 8372556b52eb..efe0d3c0215b 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
@@ -1156,21 +1156,17 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q,
 	int retval;
 	struct mqd_manager *mqd_mgr;
 
-	retval = 0;
-
-	dqm_lock(dqm);
-
 	if (dqm->total_queue_count >= max_num_of_queues_per_device) {
 		pr_warn("Can't create new usermode queue because %d queues were already created\n",
 				dqm->total_queue_count);
 		retval = -EPERM;
-		goto out_unlock;
+		goto out;
 	}
 
 	if (q->properties.type == KFD_QUEUE_TYPE_SDMA) {
 		retval = allocate_sdma_queue(dqm, &q->sdma_id);
 		if (retval)
-			goto out_unlock;
+			goto out;
 		q->properties.sdma_queue_id =
 			q->sdma_id / get_num_sdma_engines(dqm);
 		q->properties.sdma_engine_id =
@@ -1181,6 +1177,9 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q,
 	if (retval)
 		goto out_deallocate_sdma_queue;
 
+	/* Do init_mqd before dqm_lock(dqm) to avoid circular locking order:
+	 * lock(dqm) -> bo::reserve
+	 */
 	mqd_mgr = dqm->ops.get_mqd_manager(dqm,
 			get_mqd_type_from_queue_type(q->properties.type));
 
@@ -1188,6 +1187,7 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q,
 		retval = -ENOMEM;
 		goto out_deallocate_doorbell;
 	}
+
 	/*
 	 * Eviction state logic: we only mark active queues as evicted
 	 * to avoid the overhead of restoring inactive queues later
@@ -1196,9 +1196,7 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q,
 		q->properties.is_evicted = (q->properties.queue_size > 0 &&
 					    q->properties.queue_percent > 0 &&
 					    q->properties.queue_address != 0);
-
 	dqm->asic_ops.init_sdma_vm(dqm, q, qpd);
-
 	q->properties.tba_addr = qpd->tba_addr;
 	q->properties.tma_addr = qpd->tma_addr;
 	retval = mqd_mgr->init_mqd(mqd_mgr, &q->mqd, &q->mqd_mem_obj,
@@ -1206,6 +1204,8 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q,
 	if (retval)
 		goto out_deallocate_doorbell;
 
+	dqm_lock(dqm);
+
 	list_add(&q->list, &qpd->queues_list);
 	qpd->queue_count++;
 	if (q->properties.is_active) {
@@ -1233,9 +1233,7 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q,
 out_deallocate_sdma_queue:
 	if (q->properties.type == KFD_QUEUE_TYPE_SDMA)
 		deallocate_sdma_queue(dqm, q->sdma_id);
-out_unlock:
-	dqm_unlock(dqm);
-
+out:
 	return retval;
 }
 
@@ -1398,8 +1396,6 @@ static int destroy_queue_cpsch(struct device_queue_manager *dqm,
 			qpd->reset_wavefronts = true;
 	}
 
-	mqd_mgr->uninit_mqd(mqd_mgr, q->mqd, q->mqd_mem_obj);
-
 	/*
 	 * Unconditionally decrement this counter, regardless of the queue's
 	 * type
@@ -1410,6 +1406,9 @@ static int destroy_queue_cpsch(struct device_queue_manager *dqm,
 
 	dqm_unlock(dqm);
 
+	/* Do uninit_mqd after dqm_unlock(dqm) to avoid circular locking */
+	mqd_mgr->uninit_mqd(mqd_mgr, q->mqd, q->mqd_mem_obj);
+
 	return retval;
 
 failed:
@@ -1631,7 +1630,11 @@ static int process_termination_cpsch(struct device_queue_manager *dqm,
 		qpd->reset_wavefronts = false;
 	}
 
-	/* lastly, free mqd resources */
+	dqm_unlock(dqm);
+
+	/* Lastly, free mqd resources.
+	 * Do uninit_mqd() after dqm_unlock to avoid circular locking.
+	 */
 	list_for_each_entry_safe(q, next, &qpd->queues_list, list) {
 		mqd_mgr = dqm->ops.get_mqd_manager(dqm,
 			get_mqd_type_from_queue_type(q->properties.type));
@@ -1645,7 +1648,6 @@ static int process_termination_cpsch(struct device_queue_manager *dqm,
 	}
 
 out:
-	dqm_unlock(dqm);
 	return retval;
 }
 
-- 
2.17.1

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