Introduce xe_svm_ranges_zap_ptes_in_range(), a function to zap page table
entries (PTEs) for all SVM ranges within a user-specified address range.
-v2 (Matthew Brost)
Lock should be called even for tlb_invalidation
v3(Matthew Brost)
- Update comment
- s/notifier->itree.start/drm_gpusvm_notifier_start
- s/notifier->itree.last + 1/drm_gpusvm_notifier_end
- use WRITE_ONCE
Cc: Matthew Brost <matthew.br...@intel.com>
Signed-off-by: Himal Prasad Ghimiray <himal.prasad.ghimi...@intel.com>
Reviewed-by: Matthew Brost <matthew.br...@intel.com>
---
drivers/gpu/drm/xe/xe_pt.c | 14 ++++++++++-
drivers/gpu/drm/xe/xe_svm.c | 50 +++++++++++++++++++++++++++++++++++++
drivers/gpu/drm/xe/xe_svm.h | 8 ++++++
3 files changed, 71 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/xe/xe_pt.c b/drivers/gpu/drm/xe/xe_pt.c
index ba7a50bf3a2d..bf50a821853e 100644
--- a/drivers/gpu/drm/xe/xe_pt.c
+++ b/drivers/gpu/drm/xe/xe_pt.c
@@ -950,7 +950,19 @@ bool xe_pt_zap_ptes_range(struct xe_tile *tile, struct
xe_vm *vm,
struct xe_pt *pt = vm->pt_root[tile->id];
u8 pt_mask = (range->tile_present & ~range->tile_invalidated);
- xe_svm_assert_in_notifier(vm);
+ /*
+ * Locking rules:
+ *
+ * - notifier_lock (write): full protection against page table changes
+ * and MMU notifier invalidations.
+ *
+ * - notifier_lock (read) + vm_lock (write): combined protection against
+ * invalidations and concurrent page table modifications. (e.g.,
madvise)
+ *
+ */
+ lockdep_assert(lockdep_is_held_type(&vm->svm.gpusvm.notifier_lock, 0) ||
+ (lockdep_is_held_type(&vm->svm.gpusvm.notifier_lock, 1)
&&
+ lockdep_is_held_type(&vm->lock, 0)));
if (!(pt_mask & BIT(tile->id)))
return false;
diff --git a/drivers/gpu/drm/xe/xe_svm.c b/drivers/gpu/drm/xe/xe_svm.c
index ce42100cb753..c2306000f15e 100644
--- a/drivers/gpu/drm/xe/xe_svm.c
+++ b/drivers/gpu/drm/xe/xe_svm.c
@@ -1031,6 +1031,56 @@ int xe_svm_range_get_pages(struct xe_vm *vm, struct
xe_svm_range *range,
return err;
}
+/**
+ * xe_svm_ranges_zap_ptes_in_range - clear ptes of svm ranges in input range
+ * @vm: Pointer to the xe_vm structure
+ * @start: Start of the input range
+ * @end: End of the input range
+ *
+ * This function removes the page table entries (PTEs) associated
+ * with the svm ranges within the given input start and end
+ *
+ * Return: tile_mask for which gt's need to be tlb invalidated.
+ */
+u8 xe_svm_ranges_zap_ptes_in_range(struct xe_vm *vm, u64 start, u64 end)
+{
+ struct drm_gpusvm_notifier *notifier;
+ struct xe_svm_range *range;
+ u64 adj_start, adj_end;
+ struct xe_tile *tile;
+ u8 tile_mask = 0;
+ u8 id;
+
+ lockdep_assert(lockdep_is_held_type(&vm->svm.gpusvm.notifier_lock, 1) &&
+ lockdep_is_held_type(&vm->lock, 0));
+
+ drm_gpusvm_for_each_notifier(notifier, &vm->svm.gpusvm, start, end) {
+ struct drm_gpusvm_range *r = NULL;
+
+ adj_start = max(start, drm_gpusvm_notifier_start(notifier));
+ adj_end = min(end, drm_gpusvm_notifier_end(notifier));
+ drm_gpusvm_for_each_range(r, notifier, adj_start, adj_end) {
+ range = to_xe_range(r);
+ for_each_tile(tile, vm->xe, id) {
+ if (xe_pt_zap_ptes_range(tile, vm, range)) {
+ tile_mask |= BIT(id);
+ /*
+ * WRITE_ONCE pairs with READ_ONCE in
+ * xe_vm_has_valid_gpu_mapping().
+ * Must not fail after setting
+ * tile_invalidated and before
+ * TLB invalidation.
+ */
+ WRITE_ONCE(range->tile_invalidated,
+ range->tile_invalidated |
BIT(id));
+ }
+ }
+ }
+ }
+
+ return tile_mask;
+}
+
#if IS_ENABLED(CONFIG_DRM_XE_PAGEMAP)
static struct drm_pagemap *tile_local_pagemap(struct xe_tile *tile)
diff --git a/drivers/gpu/drm/xe/xe_svm.h b/drivers/gpu/drm/xe/xe_svm.h
index 184b3f4f0b2a..046a9c4e95c2 100644
--- a/drivers/gpu/drm/xe/xe_svm.h
+++ b/drivers/gpu/drm/xe/xe_svm.h
@@ -92,6 +92,8 @@ u64 xe_svm_find_vma_start(struct xe_vm *vm, u64 addr, u64
end, struct xe_vma *v
void xe_svm_unmap_address_range(struct xe_vm *vm, u64 start, u64 end);
+u8 xe_svm_ranges_zap_ptes_in_range(struct xe_vm *vm, u64 start, u64 end);
+
/**
* xe_svm_range_has_dma_mapping() - SVM range has DMA mapping
* @range: SVM range
@@ -310,6 +312,12 @@ void xe_svm_unmap_address_range(struct xe_vm *vm, u64
start, u64 end)
{
}
+static inline
+u8 xe_svm_ranges_zap_ptes_in_range(struct xe_vm *vm, u64 start, u64 end)
+{
+ return 0;
+}
+
#define xe_svm_assert_in_notifier(...) do {} while (0)
#define xe_svm_range_has_dma_mapping(...) false
--
2.34.1
