drm/i915: Move cmd parser pinning to execbuffer

We need to get rid of allocations in the cmd parser, because it needs
to be called from a signaling context, first move all pinning to
execbuf, where we already hold all locks.

Allocate jump_whitelist in the execbuffer, and add annotations around
intel_engine_cmd_parser(), to ensure we only call the command parser
without allocating any memory, or taking any locks we're not supposed to.

Because i915_gem_object_get_page() may also allocate memory, add a
path to i915_gem_object_get_sg() that prevents memory allocations,
and walk the sg list manually. It should be similarly fast.

This has the added benefit of being able to catch all memory allocation
errors before the point of no return, and return -ENOMEM safely to the
execbuf submitter.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Acked-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210323155059.628690-4-maarten.lankhorst@linux.intel.com

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/i915_memcpy.c b/drivers/gpu/drm/i915/i915_memcpy.c
index 7b3b83bd5ab8..1b021a4902de 100644
--- a/drivers/gpu/drm/i915/i915_memcpy.c
+++ b/drivers/gpu/drm/i915/i915_memcpy.c
@@ -135,7 +135,7 @@ bool i915_memcpy_from_wc(void *dst, const void *src, unsigned long len)
  * accepts that its arguments may not be aligned, but are valid for the
  * potential 16-byte read past the end.
  */
-void i915_unaligned_memcpy_from_wc(void *dst, void *src, unsigned long len)
+void i915_unaligned_memcpy_from_wc(void *dst, const void *src, unsigned long len)
 {
 	unsigned long addr;