[PATCH 07/22] drm/xe/svm: Add helper for binding hmm range to gpu
Oak Zeng
oak.zeng at intel.com
Thu Dec 21 04:37:57 UTC 2023
Add helper function xe_bind_svm_range to bind a svm range
to gpu. A temporary xe_vma is created locally to re-use
existing page table update functions which are vma-based.
The svm page table update lock design is different from
userptr and bo page table update. A xe_pt_svm_pre_commit
function is introduced for svm range pre-commitment.
A hmm_range pointer is added to xe_vma struct.
Signed-off-by: Oak Zeng <oak.zeng at intel.com>
Cc: Niranjana Vishwanathapura <niranjana.vishwanathapura at intel.com>
Cc: Matthew Brost <matthew.brost at intel.com>
Cc: Thomas Hellström <thomas.hellstrom at intel.com>
Cc: Brian Welty <brian.welty at intel.com>
---
drivers/gpu/drm/xe/xe_pt.c | 101 ++++++++++++++++++++++++++++++-
drivers/gpu/drm/xe/xe_pt.h | 4 ++
drivers/gpu/drm/xe/xe_vm_types.h | 10 +++
3 files changed, 113 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/xe/xe_pt.c b/drivers/gpu/drm/xe/xe_pt.c
index de1030a47588..65cfac88ab2f 100644
--- a/drivers/gpu/drm/xe/xe_pt.c
+++ b/drivers/gpu/drm/xe/xe_pt.c
@@ -17,6 +17,7 @@
#include "xe_trace.h"
#include "xe_ttm_stolen_mgr.h"
#include "xe_vm.h"
+#include "xe_svm.h"
struct xe_pt_dir {
struct xe_pt pt;
@@ -617,7 +618,10 @@ xe_pt_stage_bind(struct xe_tile *tile, struct xe_vma *vma,
xe_bo_assert_held(bo);
if (!xe_vma_is_null(vma)) {
- if (xe_vma_is_userptr(vma))
+ if (vma->svm_sg)
+ xe_res_first_sg(vma->svm_sg, 0, xe_vma_size(vma),
+ &curs);
+ else if (xe_vma_is_userptr(vma))
xe_res_first_sg(vma->userptr.sg, 0, xe_vma_size(vma),
&curs);
else if (xe_bo_is_vram(bo) || xe_bo_is_stolen(bo))
@@ -1046,6 +1050,28 @@ static int xe_pt_userptr_pre_commit(struct xe_migrate_pt_update *pt_update)
return 0;
}
+static int xe_pt_svm_pre_commit(struct xe_migrate_pt_update *pt_update)
+{
+ struct xe_vma *vma = pt_update->vma;
+ struct hmm_range *range = vma->hmm_range;
+
+ if (mmu_interval_read_retry(range->notifier,
+ range->notifier_seq)) {
+ /*
+ * FIXME: is this really necessary? We didn't update GPU
+ * page table yet...
+ */
+ xe_vm_invalidate_vma(vma);
+ return -EAGAIN;
+ }
+ return 0;
+}
+
+static const struct xe_migrate_pt_update_ops svm_bind_ops = {
+ .populate = xe_vm_populate_pgtable,
+ .pre_commit = xe_pt_svm_pre_commit,
+};
+
static const struct xe_migrate_pt_update_ops bind_ops = {
.populate = xe_vm_populate_pgtable,
.pre_commit = xe_pt_pre_commit,
@@ -1197,7 +1223,8 @@ __xe_pt_bind_vma(struct xe_tile *tile, struct xe_vma *vma, struct xe_exec_queue
struct xe_vm_pgtable_update entries[XE_VM_MAX_LEVEL * 2 + 1];
struct xe_pt_migrate_pt_update bind_pt_update = {
.base = {
- .ops = xe_vma_is_userptr(vma) ? &userptr_bind_ops : &bind_ops,
+ .ops = vma->svm_sg ? &svm_bind_ops :
+ (xe_vma_is_userptr(vma) ? &userptr_bind_ops : &bind_ops),
.vma = vma,
.tile_id = tile->id,
},
@@ -1651,3 +1678,73 @@ __xe_pt_unbind_vma(struct xe_tile *tile, struct xe_vma *vma, struct xe_exec_queu
return fence;
}
+
+/**
+ * xe_bind_svm_range() - bind an address range to vm
+ *
+ * @vm: the vm to bind this address range
+ * @tile: the tile to bind this address range to
+ * @range: a hmm_range which includes all the information
+ * needed for binding: virtual address range and physical
+ * pfns to back up this virtual address range.
+ * @flags: the binding flags to set in pte
+ *
+ * This is a helper function used by svm sub-system
+ * to bind a svm range to gpu vm. svm sub-system
+ * doesn't have xe_vma, thus helpers such as
+ * __xe_pt_bind_vma can't be used directly. So this
+ * helper is written for svm sub-system to use.
+ *
+ * This is a synchronous function. When this function
+ * returns, either the svm range is bound to GPU, or
+ * error happened.
+ *
+ * Return: 0 for success or error code for failure
+ * If -EAGAIN returns, it means mmu notifier was called (
+ * aka there was concurrent cpu page table update) during
+ * this function, caller has to retry hmm_range_fault
+ */
+int xe_bind_svm_range(struct xe_vm *vm, struct xe_tile *tile,
+ struct hmm_range *range, u64 flags)
+{
+ struct dma_fence *fence = NULL;
+ struct xe_svm *svm = vm->svm;
+ int ret = 0;
+ /*
+ * Create a temp vma to reuse page table helpers such as
+ * __xe_pt_bind_vma
+ */
+ struct xe_vma vma = {
+ .gpuva = {
+ .va = {
+ .addr = range->start,
+ .range = range->end - range->start + 1,
+ },
+ .vm = &vm->gpuvm,
+ .flags = flags,
+ },
+ .tile_mask = 0x1 << tile->id,
+ .hmm_range = range,
+ };
+
+ xe_svm_build_sg(range, &vma.svm_sgt);
+ vma.svm_sg = &vma.svm_sgt;
+
+ mutex_lock(&svm->mutex);
+ if (mmu_interval_read_retry(range->notifier, range->notifier_seq)) {
+ ret = -EAGAIN;
+ goto unlock;
+ }
+ fence = __xe_pt_bind_vma(tile, &vma, vm->q[tile->id], NULL, 0, false);
+
+unlock:
+ mutex_unlock(&svm->mutex);
+ sg_free_table(vma.svm_sg);
+
+ if (IS_ERR(fence))
+ return PTR_ERR(fence);
+
+ dma_fence_wait(fence, false);
+ dma_fence_put(fence);
+ return ret;
+}
diff --git a/drivers/gpu/drm/xe/xe_pt.h b/drivers/gpu/drm/xe/xe_pt.h
index 71a4fbfcff43..775d08707466 100644
--- a/drivers/gpu/drm/xe/xe_pt.h
+++ b/drivers/gpu/drm/xe/xe_pt.h
@@ -17,6 +17,8 @@ struct xe_sync_entry;
struct xe_tile;
struct xe_vm;
struct xe_vma;
+struct xe_svm;
+struct hmm_range;
/* Largest huge pte is currently 1GiB. May become device dependent. */
#define MAX_HUGEPTE_LEVEL 2
@@ -45,4 +47,6 @@ __xe_pt_unbind_vma(struct xe_tile *tile, struct xe_vma *vma, struct xe_exec_queu
bool xe_pt_zap_ptes(struct xe_tile *tile, struct xe_vma *vma);
+int xe_bind_svm_range(struct xe_vm *vm, struct xe_tile *tile,
+ struct hmm_range *range, u64 flags);
#endif
diff --git a/drivers/gpu/drm/xe/xe_vm_types.h b/drivers/gpu/drm/xe/xe_vm_types.h
index 037fb7168c63..deefe2364667 100644
--- a/drivers/gpu/drm/xe/xe_vm_types.h
+++ b/drivers/gpu/drm/xe/xe_vm_types.h
@@ -21,6 +21,7 @@ struct xe_svm;
struct xe_bo;
struct xe_sync_entry;
struct xe_vm;
+struct hmm_range;
#define TEST_VM_ASYNC_OPS_ERROR
#define FORCE_ASYNC_OP_ERROR BIT(31)
@@ -112,6 +113,15 @@ struct xe_vma {
* user pointers
*/
struct xe_userptr userptr;
+
+ /**
+ * @svm_sgt: a scatter gather table to save svm virtual address range's
+ * pfns
+ */
+ struct sg_table svm_sgt;
+ struct sg_table *svm_sg;
+ /** hmm range of this pt update, used by svm */
+ struct hmm_range *hmm_range;
};
struct xe_device;
--
2.26.3
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