drm/amdkfd: add svm ioctl GET_ATTR op

Get the intersection of attributes over all memory in the given
range
Signed-off-by: Philip Yang <Philip.Yang@amd.com>
Signed-off-by: Alex Sierra <alex.sierra@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdkfd/kfd_svm.c

@@ -706,6 +706,167 @@ svm_range_set_attr(struct kfd_process *p, uint64_t start, uint64_t size,
 	return r;
 }
 
+static int
+svm_range_get_attr(struct kfd_process *p, uint64_t start, uint64_t size,
+		   uint32_t nattr, struct kfd_ioctl_svm_attribute *attrs)
+{
+	DECLARE_BITMAP(bitmap_access, MAX_GPU_INSTANCE);
+	DECLARE_BITMAP(bitmap_aip, MAX_GPU_INSTANCE);
+	bool get_preferred_loc = false;
+	bool get_prefetch_loc = false;
+	bool get_granularity = false;
+	bool get_accessible = false;
+	bool get_flags = false;
+	uint64_t last = start + size - 1UL;
+	struct mm_struct *mm = current->mm;
+	uint8_t granularity = 0xff;
+	struct interval_tree_node *node;
+	struct svm_range_list *svms;
+	struct svm_range *prange;
+	uint32_t prefetch_loc = KFD_IOCTL_SVM_LOCATION_UNDEFINED;
+	uint32_t location = KFD_IOCTL_SVM_LOCATION_UNDEFINED;
+	uint32_t flags = 0xffffffff;
+	int gpuidx;
+	uint32_t i;
+
+	pr_debug("svms 0x%p [0x%llx 0x%llx] nattr 0x%x\n", &p->svms, start,
+		 start + size - 1, nattr);
+
+	mmap_read_lock(mm);
+	if (!svm_range_is_valid(mm, start, size)) {
+		pr_debug("invalid range\n");
+		mmap_read_unlock(mm);
+		return -EINVAL;
+	}
+	mmap_read_unlock(mm);
+
+	for (i = 0; i < nattr; i++) {
+		switch (attrs[i].type) {
+		case KFD_IOCTL_SVM_ATTR_PREFERRED_LOC:
+			get_preferred_loc = true;
+			break;
+		case KFD_IOCTL_SVM_ATTR_PREFETCH_LOC:
+			get_prefetch_loc = true;
+			break;
+		case KFD_IOCTL_SVM_ATTR_ACCESS:
+			get_accessible = true;
+			break;
+		case KFD_IOCTL_SVM_ATTR_SET_FLAGS:
+			get_flags = true;
+			break;
+		case KFD_IOCTL_SVM_ATTR_GRANULARITY:
+			get_granularity = true;
+			break;
+		case KFD_IOCTL_SVM_ATTR_CLR_FLAGS:
+		case KFD_IOCTL_SVM_ATTR_ACCESS_IN_PLACE:
+		case KFD_IOCTL_SVM_ATTR_NO_ACCESS:
+			fallthrough;
+		default:
+			pr_debug("get invalid attr type 0x%x\n", attrs[i].type);
+			return -EINVAL;
+		}
+	}
+
+	svms = &p->svms;
+
+	mutex_lock(&svms->lock);
+
+	node = interval_tree_iter_first(&svms->objects, start, last);
+	if (!node) {
+		pr_debug("range attrs not found return default values\n");
+		svm_range_set_default_attributes(&location, &prefetch_loc,
+						 &granularity, &flags);
+		/* TODO: Automatically create SVM ranges and map them on
+		 * GPU page faults
+		if (p->xnack_enabled)
+			bitmap_fill(bitmap_access, MAX_GPU_INSTANCE);
+		 */
+
+		goto fill_values;
+	}
+	bitmap_fill(bitmap_access, MAX_GPU_INSTANCE);
+	bitmap_fill(bitmap_aip, MAX_GPU_INSTANCE);
+
+	while (node) {
+		struct interval_tree_node *next;
+
+		prange = container_of(node, struct svm_range, it_node);
+		next = interval_tree_iter_next(node, start, last);
+
+		if (get_preferred_loc) {
+			if (prange->preferred_loc ==
+					KFD_IOCTL_SVM_LOCATION_UNDEFINED ||
+			    (location != KFD_IOCTL_SVM_LOCATION_UNDEFINED &&
+			     location != prange->preferred_loc)) {
+				location = KFD_IOCTL_SVM_LOCATION_UNDEFINED;
+				get_preferred_loc = false;
+			} else {
+				location = prange->preferred_loc;
+			}
+		}
+		if (get_prefetch_loc) {
+			if (prange->prefetch_loc ==
+					KFD_IOCTL_SVM_LOCATION_UNDEFINED ||
+			    (prefetch_loc != KFD_IOCTL_SVM_LOCATION_UNDEFINED &&
+			     prefetch_loc != prange->prefetch_loc)) {
+				prefetch_loc = KFD_IOCTL_SVM_LOCATION_UNDEFINED;
+				get_prefetch_loc = false;
+			} else {
+				prefetch_loc = prange->prefetch_loc;
+			}
+		}
+		if (get_accessible) {
+			bitmap_and(bitmap_access, bitmap_access,
+				   prange->bitmap_access, MAX_GPU_INSTANCE);
+			bitmap_and(bitmap_aip, bitmap_aip,
+				   prange->bitmap_aip, MAX_GPU_INSTANCE);
+		}
+		if (get_flags)
+			flags &= prange->flags;
+
+		if (get_granularity && prange->granularity < granularity)
+			granularity = prange->granularity;
+
+		node = next;
+	}
+fill_values:
+	mutex_unlock(&svms->lock);
+
+	for (i = 0; i < nattr; i++) {
+		switch (attrs[i].type) {
+		case KFD_IOCTL_SVM_ATTR_PREFERRED_LOC:
+			attrs[i].value = location;
+			break;
+		case KFD_IOCTL_SVM_ATTR_PREFETCH_LOC:
+			attrs[i].value = prefetch_loc;
+			break;
+		case KFD_IOCTL_SVM_ATTR_ACCESS:
+			gpuidx = kfd_process_gpuidx_from_gpuid(p,
+							       attrs[i].value);
+			if (gpuidx < 0) {
+				pr_debug("invalid gpuid %x\n", attrs[i].value);
+				return -EINVAL;
+			}
+			if (test_bit(gpuidx, bitmap_access))
+				attrs[i].type = KFD_IOCTL_SVM_ATTR_ACCESS;
+			else if (test_bit(gpuidx, bitmap_aip))
+				attrs[i].type =
+					KFD_IOCTL_SVM_ATTR_ACCESS_IN_PLACE;
+			else
+				attrs[i].type = KFD_IOCTL_SVM_ATTR_NO_ACCESS;
+			break;
+		case KFD_IOCTL_SVM_ATTR_SET_FLAGS:
+			attrs[i].value = flags;
+			break;
+		case KFD_IOCTL_SVM_ATTR_GRANULARITY:
+			attrs[i].value = (uint32_t)granularity;
+			break;
+		}
+	}
+
+	return 0;
+}
+
 int
 svm_ioctl(struct kfd_process *p, enum kfd_ioctl_svm_op op, uint64_t start,
 	  uint64_t size, uint32_t nattrs, struct kfd_ioctl_svm_attribute *attrs)
@@ -719,6 +880,9 @@ svm_ioctl(struct kfd_process *p, enum kfd_ioctl_svm_op op, uint64_t start,
 	case KFD_IOCTL_SVM_OP_SET_ATTR:
 		r = svm_range_set_attr(p, start, size, nattrs, attrs);
 		break;
+	case KFD_IOCTL_SVM_OP_GET_ATTR:
+		r = svm_range_get_attr(p, start, size, nattrs, attrs);
+		break;
 	default:
 		r = EINVAL;
 		break;