drm/i915: simplify allocation of driver-internal requests
There are a number of places where the driver needs a request, but isn't
working on behalf of any specific user or in a specific context. At
present, we associate them with the per-engine default context. A future
patch will abolish those per-engine context pointers; but we can already
eliminate a lot of the references to them, just by making the allocator
allow NULL as a shorthand for "an appropriate context for this ring",
which will mean that the callers don't need to know anything about how
the "appropriate context" is found (e.g. per-ring vs per-device, etc).
So this patch renames the existing i915_gem_request_alloc(), and makes
it local (static inline), and replaces it with a wrapper that provides
a default if the context is NULL, and also has a nicer calling
convention (doesn't require a pointer to an output parameter). Then we
change all callers to use the new convention:
OLD:
err = i915_gem_request_alloc(ring, user_ctx, &req);
if (err) ...
NEW:
req = i915_gem_request_alloc(ring, user_ctx);
if (IS_ERR(req)) ...
OLD:
err = i915_gem_request_alloc(ring, ring->default_context, &req);
if (err) ...
NEW:
req = i915_gem_request_alloc(ring, NULL);
if (IS_ERR(req)) ...
v4: Rebased
Signed-off-by: Dave Gordon <david.s.gordon@intel.com>
Reviewed-by: Nick Hoath <nicholas.hoath@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1453230175-19330-2-git-send-email-david.s.gordon@intel.com
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 6b0102d..8e716b6 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2690,9 +2690,10 @@
kmem_cache_free(req->i915->requests, req);
}
-int i915_gem_request_alloc(struct intel_engine_cs *ring,
- struct intel_context *ctx,
- struct drm_i915_gem_request **req_out)
+static inline int
+__i915_gem_request_alloc(struct intel_engine_cs *ring,
+ struct intel_context *ctx,
+ struct drm_i915_gem_request **req_out)
{
struct drm_i915_private *dev_priv = to_i915(ring->dev);
struct drm_i915_gem_request *req;
@@ -2755,6 +2756,31 @@
return ret;
}
+/**
+ * i915_gem_request_alloc - allocate a request structure
+ *
+ * @engine: engine that we wish to issue the request on.
+ * @ctx: context that the request will be associated with.
+ * This can be NULL if the request is not directly related to
+ * any specific user context, in which case this function will
+ * choose an appropriate context to use.
+ *
+ * Returns a pointer to the allocated request if successful,
+ * or an error code if not.
+ */
+struct drm_i915_gem_request *
+i915_gem_request_alloc(struct intel_engine_cs *engine,
+ struct intel_context *ctx)
+{
+ struct drm_i915_gem_request *req;
+ int err;
+
+ if (ctx == NULL)
+ ctx = engine->default_context;
+ err = __i915_gem_request_alloc(engine, ctx, &req);
+ return err ? ERR_PTR(err) : req;
+}
+
void i915_gem_request_cancel(struct drm_i915_gem_request *req)
{
intel_ring_reserved_space_cancel(req->ringbuf);
@@ -3172,9 +3198,13 @@
return 0;
if (*to_req == NULL) {
- ret = i915_gem_request_alloc(to, to->default_context, to_req);
- if (ret)
- return ret;
+ struct drm_i915_gem_request *req;
+
+ req = i915_gem_request_alloc(to, NULL);
+ if (IS_ERR(req))
+ return PTR_ERR(req);
+
+ *to_req = req;
}
trace_i915_gem_ring_sync_to(*to_req, from, from_req);
@@ -3374,9 +3404,9 @@
if (!i915.enable_execlists) {
struct drm_i915_gem_request *req;
- ret = i915_gem_request_alloc(ring, ring->default_context, &req);
- if (ret)
- return ret;
+ req = i915_gem_request_alloc(ring, NULL);
+ if (IS_ERR(req))
+ return PTR_ERR(req);
ret = i915_switch_context(req);
if (ret) {
@@ -4871,10 +4901,9 @@
for_each_ring(ring, dev_priv, i) {
struct drm_i915_gem_request *req;
- WARN_ON(!ring->default_context);
-
- ret = i915_gem_request_alloc(ring, ring->default_context, &req);
- if (ret) {
+ req = i915_gem_request_alloc(ring, NULL);
+ if (IS_ERR(req)) {
+ ret = PTR_ERR(req);
i915_gem_cleanup_ringbuffer(dev);
goto out;
}