[Intel-gfx] [PATCH 1/2] drm/i915: Don't allow setting I915_CONTEXT_PARAM_VM twice

Jason Ekstrand
2021-07-10T21:26:45Z

Allowing setting it multiple times brings no real utility to the API, no
userspace relies on it, and it does make i915 a tiny bit more
complicated. Let's disallow it for now unless someone comes up with a
compelling reason to support it.

Signed-off-by: Jason Ekstrand <jason@jlekstrand.net>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
---
drivers/gpu/drm/i915/gem/i915_gem_context.c | 12 +++++-------
1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index 7d6f52d8a8012..5853737cc79f3 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -319,7 +319,6 @@ static int set_proto_ctx_vm(struct drm_i915_file_private *fpriv,
const struct drm_i915_gem_context_param *args)
{
struct drm_i915_private *i915 = fpriv->dev_priv;
- struct i915_address_space *vm;

if (args->size)
return -EINVAL;
@@ -327,17 +326,16 @@ static int set_proto_ctx_vm(struct drm_i915_file_private *fpriv,
if (!HAS_FULL_PPGTT(i915))
return -ENODEV;

+ if (pc->vm)
+ return -EINVAL;
+
if (upper_32_bits(args->value))
return -ENOENT;

- vm = i915_gem_vm_lookup(fpriv, args->value);
- if (!vm)
+ pc->vm = i915_gem_vm_lookup(fpriv, args->value);
+ if (!pc->vm)
return -ENOENT;

- if (pc->vm)
- i915_vm_put(pc->vm);
- pc->vm = vm;
-
return 0;
}

--
2.31.1