And wire it up as well.
Signed-off-by: Christian König <christian.koenig at amd.com>
---
Documentation/gpu/amdgpu.rst | 9 +++++
drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c | 74 ++++++++++++++++++++++++++--------
2 files changed, 67 insertions(+), 16 deletions(-)
diff --git a/Documentation/gpu/amdgpu.rst b/Documentation/gpu/amdgpu.rst
index 1fbf3876a3d8..420271081c31 100644
--- a/Documentation/gpu/amdgpu.rst
+++ b/Documentation/gpu/amdgpu.rst
@@ -35,3 +35,12 @@ PRIME Buffer Sharing
.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_prime.c
:internal:
+
+MMU Notifier
+--------------------
+
+.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
+ :doc: MMU Notifier
+
+.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
+ :internal:
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
index 36ed7b1b6cf0..9e44b6e21e67 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
@@ -28,6 +28,21 @@
* Christian König <christian.koenig at amd.com>
*/
+/**
+ * DOC: amdgpu MMU notifier
+ *
+ * For coherent userptr handling registers an MMU notifier to inform the driver
+ * about updates on a page tables of a process.
+ *
+ * When somebody tries to invalidate the page tables we block the update until
+ * all operations on the pages in question are completed, then those pages are
+ * marked as accessed and also dirty if it wasn't a read only access.
+ *
+ * New command submissions using the userptrs in question are delayed until all
+ * page table invalidation are completed and we once more see a coherent process
+ * address space.
+ */
+
#include <linux/firmware.h>
#include <linux/module.h>
#include <linux/mmu_notifier.h>
@@ -37,6 +52,21 @@
#include "amdgpu.h"
+/**
+ * struct amdgpu_mn
+ *
+ * @adev: amdgpu device pointer
+ * @mm: process address space
+ * @mn: MMU notifier structur
+ * @work: destrution 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
+ * @read_lock: mutex for recursive locking of @lock
+ * @recursion: depth of recursion
+ *
+ * Data for each amdgpu device and process address space.
+ */
struct amdgpu_mn {
/* constant after initialisation */
struct amdgpu_device *adev;
@@ -56,13 +86,21 @@ struct amdgpu_mn {
atomic_t recursion;
};
+/**
+ * struct amdgpu_mn_node
+ *
+ * @it: interval node defining start-last of the affected address range
+ * @bos: list of all BOs in the affected address range
+ *
+ * Manages all BOs which are affected of a certain range of address space.
+ */
struct amdgpu_mn_node {
struct interval_tree_node it;
struct list_head bos;
};
/**
- * amdgpu_mn_destroy - destroy the amn
+ * amdgpu_mn_destroy - destroy the MMU notifier
*
* @work: previously sheduled work item
*
@@ -96,7 +134,7 @@ static void amdgpu_mn_destroy(struct work_struct *work)
* amdgpu_mn_release - callback to notify about mm destruction
*
* @mn: our notifier
- * @mn: the mm this callback is about
+ * @mm: the mm this callback is about
*
* Shedule a work item to lazy destroy our notifier.
*/
@@ -104,13 +142,16 @@ static void amdgpu_mn_release(struct mmu_notifier *mn,
struct mm_struct *mm)
{
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 mn
+ * amdgpu_mn_lock - take the write side lock for this notifier
+ *
+ * @mn: our notifier
*/
void amdgpu_mn_lock(struct amdgpu_mn *mn)
{
@@ -119,7 +160,9 @@ void amdgpu_mn_lock(struct amdgpu_mn *mn)
}
/**
- * amdgpu_mn_unlock - drop the write side lock for this mn
+ * amdgpu_mn_unlock - drop the write side lock for this notifier
+ *
+ * @mn: our notifier
*/
void amdgpu_mn_unlock(struct amdgpu_mn *mn)
{
@@ -128,11 +171,9 @@ void amdgpu_mn_unlock(struct amdgpu_mn *mn)
}
/**
- * amdgpu_mn_read_lock - take the amn read lock
+ * amdgpu_mn_read_lock - take the read side lock for this notifier
*
* @amn: our notifier
- *
- * Take the amn read side lock.
*/
static void amdgpu_mn_read_lock(struct amdgpu_mn *amn)
{
@@ -143,11 +184,9 @@ static void amdgpu_mn_read_lock(struct amdgpu_mn *amn)
}
/**
- * amdgpu_mn_read_unlock - drop the amn read lock
+ * amdgpu_mn_read_unlock - drop the read side lock for this notifier
*
* @amn: our notifier
- *
- * Drop the amn read side lock.
*/
static void amdgpu_mn_read_unlock(struct amdgpu_mn *amn)
{
@@ -159,9 +198,11 @@ static void amdgpu_mn_read_unlock(struct amdgpu_mn *amn)
* amdgpu_mn_invalidate_node - unmap all BOs of a node
*
* @node: the node with the BOs to unmap
+ * @start: start of address range affected
+ * @end: end of address range affected
*
- * We block for all BOs and unmap them by move them
- * into system domain again.
+ * Block for operations on BOs to finish and mark pages as accessed and
+ * potentially dirty.
*/
static void amdgpu_mn_invalidate_node(struct amdgpu_mn_node *node,
unsigned long start,
@@ -188,12 +229,12 @@ static void amdgpu_mn_invalidate_node(struct amdgpu_mn_node *node,
* amdgpu_mn_invalidate_range_start - callback to notify about mm change
*
* @mn: our notifier
- * @mn: the mm this callback is about
+ * @mm: the mm this callback is about
* @start: start of updated range
* @end: end of updated range
*
- * We block for all BOs between start and end to be idle and
- * unmap them by move them into system domain again.
+ * Block for operations on BOs to finish and mark pages as accessed and
+ * potentially dirty.
*/
static void amdgpu_mn_invalidate_range_start(struct mmu_notifier *mn,
struct mm_struct *mm,
@@ -223,7 +264,7 @@ static void amdgpu_mn_invalidate_range_start(struct mmu_notifier *mn,
* amdgpu_mn_invalidate_range_end - callback to notify about mm change
*
* @mn: our notifier
- * @mn: the mm this callback is about
+ * @mm: the mm this callback is about
* @start: start of updated range
* @end: end of updated range
*
@@ -391,6 +432,7 @@ void amdgpu_mn_unregister(struct amdgpu_bo *bo)
if (list_empty(head)) {
struct amdgpu_mn_node *node;
+
node = container_of(head, struct amdgpu_mn_node, bos);
interval_tree_remove(&node->it, &amn->objects);
kfree(node);
--
2.14.1
