SVM ranges are created for unregistered memory, triggered
by page faults. These ranges are migrated/mapped to
GPU VRAM memory.
Signed-off-by: Alex Sierra <alex.sierra@xxxxxxx>
---
drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 103 ++++++++++++++++++++++++++-
1 file changed, 101 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
index 45dd055118eb..a8a92c533cf7 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -2179,6 +2179,84 @@ svm_range_best_restore_location(struct svm_range *prange,
return -1;
}
+static int
+svm_range_get_range_boundaries(struct kfd_process *p, int64_t addr,
+ unsigned long *start, unsigned long *last)
+{
+ struct vm_area_struct *vma;
+ struct interval_tree_node *node;
+ unsigned long start_limit, end_limit;
+
+ vma = find_vma(p->mm, addr);
+ if (!vma || addr < vma->vm_start) {
+ pr_debug("VMA does not exist in address [0x%llx]\n", addr);
+ return -EFAULT;
+ }
+ start_limit = max(vma->vm_start,
+ (unsigned long)ALIGN_DOWN(addr, 2UL << 20)) >> PAGE_SHIFT;
+ end_limit = min(vma->vm_end,
+ (unsigned long)ALIGN(addr + 1, 2UL << 20)) >> PAGE_SHIFT;
+ /* First range that starts after the fault address */
+ node = interval_tree_iter_first(&p->svms.objects, (addr >> PAGE_SHIFT) + 1, ULONG_MAX);
+ if (node) {
+ end_limit = min(end_limit, node->start);
+ /* Last range that ends before the fault address */
+ node = container_of(rb_prev(&node->rb), struct interval_tree_node, rb);
+ } else {
+ /* Last range must end before addr because there was no range after addr */
+ node = container_of(rb_last(&p->svms.objects.rb_root),
+ struct interval_tree_node, rb);
+ }
+ if (node)
+ start_limit = max(start_limit, node->last + 1);
+
+ *start = start_limit;
+ *last = end_limit - 1;
+
+ pr_debug("vma start: %lx start: %lx vma end: %lx last: %lx\n",
+ vma->vm_start >> PAGE_SHIFT, *start,
+ vma->vm_end >> PAGE_SHIFT, *last);
+
+ return 0;
+
+}
+static struct
+svm_range *svm_range_create_unregistered_range(struct amdgpu_device *adev,
+ struct kfd_process *p,
+ struct mm_struct *mm,
+ int64_t addr)
+{
+ struct svm_range *prange = NULL;
+ struct svm_range_list *svms;
+ unsigned long start, last;
+ uint32_t gpuid, gpuidx;
+
+ if (svm_range_get_range_boundaries(p, addr << PAGE_SHIFT,
+ &start, &last))
+ return NULL;
+
+ svms = &p->svms;
+ prange = svm_range_new(&p->svms, start, last);
+ if (!prange) {
+ pr_debug("Failed to create prange in address [0x%llx]\\n", addr);
+ goto out;
+ }
+ if (kfd_process_gpuid_from_kgd(p, adev, &gpuid, &gpuidx)) {
+ pr_debug("failed to get gpuid from kgd\n");
+ svm_range_free(prange);
+ prange = NULL;
+ goto out;
+ }
+ prange->preferred_loc = gpuid;
+ prange->actual_loc = 0;
+ /* Gurantee prange is migrate it */
+ prange->validate_timestamp -= AMDGPU_SVM_RANGE_RETRY_FAULT_PENDING;
+ svm_range_add_to_svms(prange);
+ svm_range_add_notifier_locked(mm, prange);
+
+out:
+ return prange;
+}
/* svm_range_skip_recover - decide if prange can be recovered
* @prange: svm range structure
@@ -2228,6 +2306,7 @@ svm_range_restore_pages(struct amdgpu_device *adev, unsigned int pasid,
struct kfd_process *p;
uint64_t timestamp;
int32_t best_loc, gpuidx;
+ bool write_locked = false;
int r = 0;
p = kfd_lookup_process_by_pasid(pasid);
@@ -2251,14 +2330,34 @@ svm_range_restore_pages(struct amdgpu_device *adev, unsigned int pasid,
}
mmap_read_lock(mm);
+retry_write_locked:
mutex_lock(&svms->lock);
prange = svm_range_from_addr(svms, addr, NULL);
if (!prange) {
pr_debug("failed to find prange svms 0x%p address [0x%llx]\n",
svms, addr);
- r = -EFAULT;
- goto out_unlock_svms;
+ if (!write_locked) {
+ /* Need the write lock to create new range with MMU notifier.
+ * Also flush pending deferred work to make sure the interval
+ * tree is up to date before we add a new range
+ */
+ mutex_unlock(&svms->lock);
+ mmap_read_unlock(mm);
+ svm_range_list_lock_and_flush_work(svms, mm);
+ write_locked = true;
+ goto retry_write_locked;
+ }
+ prange = svm_range_create_unregistered_range(adev, p, mm, addr);
+ if (!prange) {
+ pr_debug("failed to create unregisterd range svms 0x%p address [0x%llx]\n",
+ svms, addr);
+ mmap_write_downgrade(mm);
+ r = -EFAULT;
+ goto out_unlock_svms;
+ }
}
+ if (write_locked)
+ mmap_write_downgrade(mm);
mutex_lock(&prange->migrate_mutex);
--
2.17.1
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