Revert "drm/amdgpu: use HMM callback to replace mmu notifier"

This reverts commit 57731a07795ae80790c6ae7d8e7001cdbd6d14c0.

This depends on an HMM fix which is not upstream yet.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

4 files changed, 98 insertions, 72 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/Kconfig b/drivers/gpu/drm/amd/amdgpu/Kconfig
index 960a63355705..9221e5489069 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 HMM_MIRROR
+	select MMU_NOTIFIER
 	help
-	  This option selects CONFIG_HMM and CONFIG_HMM_MIRROR if it
-	  isn't already selected to enabled full userptr support.
+	  This option selects CONFIG_MMU_NOTIFIER 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 7d539ba6400d..f8c58c425eb9 100644
--- a/drivers/gpu/drm/amd/amdgpu/Makefile
+++ b/drivers/gpu/drm/amd/amdgpu/Makefile
@@ -173,7 +173,7 @@ endif
 amdgpu-$(CONFIG_COMPAT) += amdgpu_ioc32.o
 amdgpu-$(CONFIG_VGA_SWITCHEROO) += amdgpu_atpx_handler.o
 amdgpu-$(CONFIG_ACPI) += amdgpu_acpi.o
-amdgpu-$(CONFIG_HMM_MIRROR) += amdgpu_mn.o
+amdgpu-$(CONFIG_MMU_NOTIFIER) += 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 f000704f984d..3e6823fdd939 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/hmm.h>
+#include <linux/mmu_notifier.h>
 #include <linux/interval_tree.h>
 #include <drm/drmP.h>
 #include <drm/drm.h>
@@ -58,12 +58,14 @@
  *
  * @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
  * @lock: rw semaphore protecting the notifier nodes
  * @objects: interval tree containing amdgpu_mn_nodes
- * @mirror: HMM mirror function support
+ * @read_lock: mutex for recursive locking of @lock
+ * @recursion: depth of recursion
  *
  * Data for each amdgpu device and process address space.
  */
@@ -71,6 +73,7 @@ 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 */
@@ -82,9 +85,8 @@ struct amdgpu_mn {
 	/* objects protected by lock */
 	struct rw_semaphore	lock;
 	struct rb_root_cached	objects;
-
-	/* HMM mirror */
-	struct hmm_mirror	mirror;
+	struct mutex		read_lock;
+	atomic_t		recursion;
 };
 
 /**
@@ -101,7 +103,7 @@ struct amdgpu_mn_node {
 };
 
 /**
- * amdgpu_mn_destroy - destroy the HMM mirror
+ * amdgpu_mn_destroy - destroy the MMU notifier
  *
  * @work: previously sheduled work item
  *
@@ -127,26 +129,28 @@ static void amdgpu_mn_destroy(struct work_struct *work)
 	}
 	up_write(&amn->lock);
 	mutex_unlock(&adev->mn_lock);
-
-	hmm_mirror_unregister(&amn->mirror);
+	mmu_notifier_unregister_no_release(&amn->mn, amn->mm);
 	kfree(amn);
 }
 
 /**
- * amdgpu_hmm_mirror_release - callback to notify about mm destruction
+ * amdgpu_mn_release - callback to notify about mm destruction
  *
- * @mirror: the HMM mirror (mm) this callback is about
+ * @mn: our notifier
+ * @mm: the mm this callback is about
  *
- * Shedule a work item to lazy destroy HMM mirror.
+ * Shedule a work item to lazy destroy our notifier.
  */
-static void amdgpu_hmm_mirror_release(struct hmm_mirror *mirror)
+static void amdgpu_mn_release(struct mmu_notifier *mn,
+			      struct mm_struct *mm)
 {
-	struct amdgpu_mn *amn = container_of(mirror, struct amdgpu_mn, mirror);
+	struct amdgpu_mn *amn = container_of(mn, struct amdgpu_mn, mn);
 
 	INIT_WORK(&amn->work, amdgpu_mn_destroy);
 	schedule_work(&amn->work);
 }
 
+
 /**
  * amdgpu_mn_lock - take the write side lock for this notifier
  *
@@ -177,10 +181,14 @@ void amdgpu_mn_unlock(struct amdgpu_mn *mn)
 static int amdgpu_mn_read_lock(struct amdgpu_mn *amn, bool blockable)
 {
 	if (blockable)
-		down_read(&amn->lock);
-	else if (!down_read_trylock(&amn->lock))
+		mutex_lock(&amn->read_lock);
+	else if (!mutex_trylock(&amn->read_lock))
 		return -EAGAIN;
 
+	if (atomic_inc_return(&amn->recursion) == 1)
+		down_read_non_owner(&amn->lock);
+	mutex_unlock(&amn->read_lock);
+
 	return 0;
 }
 
@@ -191,7 +199,8 @@ static int amdgpu_mn_read_lock(struct amdgpu_mn *amn, bool blockable)
  */
 static void amdgpu_mn_read_unlock(struct amdgpu_mn *amn)
 {
-	up_read(&amn->lock);
+	if (atomic_dec_return(&amn->recursion) == 0)
+		up_read_non_owner(&amn->lock);
 }
 
 /**
@@ -226,128 +235,143 @@ static void amdgpu_mn_invalidate_node(struct amdgpu_mn_node *node,
 }
 
 /**
- * amdgpu_mn_sync_pagetables_gfx - callback to notify about mm change
+ * amdgpu_mn_invalidate_range_start_gfx - callback to notify about mm change
  *
- * @mirror: the hmm_mirror (mm) is about to update
- * @update: the update start, end address
+ * @mn: our notifier
+ * @range: mmu notifier context
  *
  * Block for operations on BOs to finish and mark pages as accessed and
  * potentially dirty.
  */
-static int amdgpu_mn_sync_pagetables_gfx(struct hmm_mirror *mirror,
-			const struct hmm_update *update)
+static int amdgpu_mn_invalidate_range_start_gfx(struct mmu_notifier *mn,
+			const struct mmu_notifier_range *range)
 {
-	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 amdgpu_mn *amn = container_of(mn, struct amdgpu_mn, mn);
 	struct interval_tree_node *it;
+	unsigned long end;
 
 	/* notification is exclusive, but interval is inclusive */
-	end -= 1;
+	end = range->end - 1;
 
 	/* TODO we should be able to split locking for interval tree and
 	 * amdgpu_mn_invalidate_node
 	 */
-	if (amdgpu_mn_read_lock(amn, blockable))
+	if (amdgpu_mn_read_lock(amn, range->blockable))
 		return -EAGAIN;
 
-	it = interval_tree_iter_first(&amn->objects, start, end);
+	it = interval_tree_iter_first(&amn->objects, range->start, end);
 	while (it) {
 		struct amdgpu_mn_node *node;
 
-		if (!blockable) {
+		if (!range->blockable) {
 			amdgpu_mn_read_unlock(amn);
 			return -EAGAIN;
 		}
 
 		node = container_of(it, struct amdgpu_mn_node, it);
-		it = interval_tree_iter_next(it, start, end);
+		it = interval_tree_iter_next(it, range->start, end);
 
-		amdgpu_mn_invalidate_node(node, start, end);
+		amdgpu_mn_invalidate_node(node, range->start, end);
 	}
 
-	amdgpu_mn_read_unlock(amn);
-
 	return 0;
 }
 
 /**
- * amdgpu_mn_sync_pagetables_hsa - callback to notify about mm change
+ * amdgpu_mn_invalidate_range_start_hsa - callback to notify about mm change
  *
- * @mirror: the hmm_mirror (mm) is about to update
- * @update: the update start, end address
+ * @mn: our notifier
+ * @mm: the mm this callback is about
+ * @start: start of updated range
+ * @end: end of updated range
  *
  * 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_sync_pagetables_hsa(struct hmm_mirror *mirror,
-			const struct hmm_update *update)
+static int amdgpu_mn_invalidate_range_start_hsa(struct mmu_notifier *mn,
+			const struct mmu_notifier_range *range)
 {
-	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 amdgpu_mn *amn = container_of(mn, struct amdgpu_mn, mn);
 	struct interval_tree_node *it;
+	unsigned long end;
 
 	/* notification is exclusive, but interval is inclusive */
-	end -= 1;
+	end = range->end - 1;
 
-	if (amdgpu_mn_read_lock(amn, blockable))
+	if (amdgpu_mn_read_lock(amn, range->blockable))
 		return -EAGAIN;
 
-	it = interval_tree_iter_first(&amn->objects, start, end);
+	it = interval_tree_iter_first(&amn->objects, range->start, end);
 	while (it) {
 		struct amdgpu_mn_node *node;
 		struct amdgpu_bo *bo;
 
-		if (!blockable) {
+		if (!range->blockable) {
 			amdgpu_mn_read_unlock(amn);
 			return -EAGAIN;
 		}
 
 		node = container_of(it, struct amdgpu_mn_node, it);
-		it = interval_tree_iter_next(it, start, end);
+		it = interval_tree_iter_next(it, range->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,
-							 start, end))
-				amdgpu_amdkfd_evict_userptr(mem, amn->mm);
+							 range->start,
+							 end))
+				amdgpu_amdkfd_evict_userptr(mem, range->mm);
 		}
 	}
 
-	amdgpu_mn_read_unlock(amn);
-
 	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.
+/**
+ * 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.
  */
-#define AMDGPU_MN_KEY(mm, type) ((unsigned long)(mm) + (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);
+}
 
-static struct hmm_mirror_ops amdgpu_hmm_mirror_ops[] = {
+static const struct mmu_notifier_ops amdgpu_mn_ops[] = {
 	[AMDGPU_MN_TYPE_GFX] = {
-		.sync_cpu_device_pagetables = amdgpu_mn_sync_pagetables_gfx,
-		.release = amdgpu_hmm_mirror_release
+		.release = amdgpu_mn_release,
+		.invalidate_range_start = amdgpu_mn_invalidate_range_start_gfx,
+		.invalidate_range_end = amdgpu_mn_invalidate_range_end,
 	},
 	[AMDGPU_MN_TYPE_HSA] = {
-		.sync_cpu_device_pagetables = amdgpu_mn_sync_pagetables_hsa,
-		.release = amdgpu_hmm_mirror_release
+		.release = amdgpu_mn_release,
+		.invalidate_range_start = amdgpu_mn_invalidate_range_start_hsa,
+		.invalidate_range_end = amdgpu_mn_invalidate_range_end,
 	},
 };
 
+/* 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 HMM mirror context
+ * amdgpu_mn_get - create notifier context
  *
  * @adev: amdgpu device pointer
  * @type: type of MMU notifier context
  *
- * Creates a HMM mirror context for current->mm.
+ * Creates a notifier context for current->mm.
  */
 struct amdgpu_mn *amdgpu_mn_get(struct amdgpu_device *adev,
 				enum amdgpu_mn_type type)
@@ -377,10 +401,12 @@ 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);
 
-	amn->mirror.ops = &amdgpu_hmm_mirror_ops[type];
-	r = hmm_mirror_register(&amn->mirror, mm);
+	r = __mmu_notifier_register(&amn->mn, mm);
 	if (r)
 		goto free_amn;
 
@@ -406,7 +432,7 @@ free_amn:
  * @bo: amdgpu buffer object
  * @addr: userptr addr we should monitor
  *
- * Registers an HMM mirror for the given BO at the specified address.
+ * Registers an MMU notifier 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)
@@ -462,11 +488,11 @@ int amdgpu_mn_register(struct amdgpu_bo *bo, unsigned long addr)
 }
 
 /**
- * amdgpu_mn_unregister - unregister a BO for HMM mirror updates
+ * amdgpu_mn_unregister - unregister a BO for notifier updates
  *
  * @bo: amdgpu buffer object
  *
- * Remove any registration of HMM mirror updates from the buffer object.
+ * Remove any registration of MMU notifier 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 0a51fd00021c..eb0f432f78fe 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_HMM_MIRROR)
+#if defined(CONFIG_MMU_NOTIFIER)
 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,