[PATCH i-g-t v8 2/3] lib/xe: Add failable variant of xe_vm_bind_lr_sync()

[Sobin Thomas <sobin.thomas@intel.com>]

Add __xe_vm_bind_lr_sync helper function which returns standard error
codes instead of asserting on failure. This allows calling function
to handle VM bind failures explicitly while preserving the existing
xe_vm_bind_lr_sync() wrapper for tests.

Refactor the implementation to use proper return-code handling and
user-fence synchronization, and add xe_vm_bind_lr_failable() for
callers that expect bind / overcommit failures.

v7: Introduced xe_vm_bind_lr_sync_failable (Thomas)
v8: Modified xe_vm_bind_lr_sync_failable and xe_vm_bind_lr_sync to call
    __xe_vm_bind_lr_sync

Signed-off-by: Sobin Thomas <sobin.thomas@intel.com>
---
 lib/xe/xe_ioctl.c | 36 ++++++++++++++++++++++++++++++------
 lib/xe/xe_ioctl.h |  4 ++++
 2 files changed, 34 insertions(+), 6 deletions(-)

diff --git a/lib/xe/xe_ioctl.c b/lib/xe/xe_ioctl.c
index ea3f2fcaa..a8d315dfb 100644
--- a/lib/xe/xe_ioctl.c
+++ b/lib/xe/xe_ioctl.c
@@ -822,23 +822,47 @@ void xe_vm_madvise(int fd, uint32_t vm, uint64_t addr, uint64_t range,
 }
 
 #define	BIND_SYNC_VAL	0x686868
-void xe_vm_bind_lr_sync(int fd, uint32_t vm, uint32_t bo, uint64_t offset,
-			uint64_t addr, uint64_t size, uint32_t flags)
+int __xe_vm_bind_lr_sync(int fd, uint32_t vm, uint32_t bo, uint64_t offset,
+			 uint64_t addr, uint64_t size, uint32_t flags)
 {
-	volatile uint64_t *sync_addr = malloc(sizeof(*sync_addr));
+	uint64_t *sync_addr = malloc(sizeof(*sync_addr));
 	struct drm_xe_sync sync = {
 		.flags = DRM_XE_SYNC_FLAG_SIGNAL,
 		.type = DRM_XE_SYNC_TYPE_USER_FENCE,
 		.addr = to_user_pointer((uint64_t *)sync_addr),
 		.timeline_value = BIND_SYNC_VAL,
 	};
+	int ret = 0;
 
-	igt_assert(!!sync_addr);
-	xe_vm_bind_async_flags(fd, vm, 0, bo, 0, addr, size, &sync, 1, flags);
-	if (*sync_addr != BIND_SYNC_VAL)
+	if (!sync_addr)
+		return -ENOMEM;
+
+	WRITE_ONCE(*sync_addr, 0);
+
+	ret = __xe_vm_bind(fd, vm, 0, bo, 0, addr, size, DRM_XE_VM_BIND_OP_MAP, flags,
+			   &sync, 1, 0,  DEFAULT_PAT_INDEX, 0);
+
+	if (ret)
+		goto out;
+
+	if (READ_ONCE(*sync_addr) != BIND_SYNC_VAL)
 		xe_wait_ufence(fd, (uint64_t *)sync_addr, BIND_SYNC_VAL, 0, NSEC_PER_SEC * 10);
 	/* Only free if the wait succeeds */
+out:
 	free((void *)sync_addr);
+	return ret;
+}
+
+void xe_vm_bind_lr_sync(int fd, uint32_t vm, uint32_t bo, uint64_t offset,
+			uint64_t addr, uint64_t size, uint32_t flags)
+{
+	igt_assert_eq(__xe_vm_bind_lr_sync(fd, vm, bo, offset, addr, size, flags), 0);
+}
+
+int xe_vm_bind_lr_failable(int fd, uint32_t vm, uint32_t bo, uint64_t offset,
+			   uint64_t addr, uint64_t size, uint32_t flags)
+{
+	return __xe_vm_bind_lr_sync(fd, vm, bo, offset, addr, size, flags);
 }
 
 void xe_vm_unbind_lr_sync(int fd, uint32_t vm, uint64_t offset,
diff --git a/lib/xe/xe_ioctl.h b/lib/xe/xe_ioctl.h
index b62d259fd..a7e38ea04 100644
--- a/lib/xe/xe_ioctl.h
+++ b/lib/xe/xe_ioctl.h
@@ -117,6 +117,10 @@ struct drm_xe_mem_range_attr
 void xe_vm_bind_lr_sync(int fd, uint32_t vm, uint32_t bo,
 			uint64_t offset, uint64_t addr,
 			uint64_t size, uint32_t flags);
+int __xe_vm_bind_lr_sync(int fd, uint32_t vm, uint32_t bo, uint64_t offset,
+			 uint64_t addr, uint64_t size, uint32_t flags);
+int xe_vm_bind_lr_failable(int fd, uint32_t vm, uint32_t bo, uint64_t offset,
+			   uint64_t addr, uint64_t size, uint32_t flags);
 void xe_vm_unbind_lr_sync(int fd, uint32_t vm, uint64_t offset,
 			  uint64_t addr, uint64_t size);
 #endif /* XE_IOCTL_H */
-- 
2.52.0