[PATCH] drm/i915: Refactor golden render state emission to unconfuse gcc

Chris Wilson
2016-07-22T10:16:41Z

GCC was inlining the init and setup functions, but was getting itself
confused into thinking that variables could be used uninitialised. If we
do the inline for gcc, it is happy! As a bonus we shrink the code.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
---
drivers/gpu/drm/i915/i915_gem_render_state.c | 93 ++++++++--------------------
1 file changed, 26 insertions(+), 67 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_render_state.c b/drivers/gpu/drm/i915/i915_gem_render_state.c
index a9b56d18a93b..b50412c205e5 100644
--- a/drivers/gpu/drm/i915/i915_gem_render_state.c
+++ b/drivers/gpu/drm/i915/i915_gem_render_state.c
@@ -32,7 +32,6 @@ struct render_state {
const struct intel_renderstate_rodata *rodata;
struct drm_i915_gem_object *obj;
u64 ggtt_offset;
- int gen;
u32 aux_batch_size;
u32 aux_batch_offset;
};
@@ -54,36 +53,6 @@ render_state_get_rodata(const int gen)
return NULL;
}

-static int render_state_init(struct render_state *so,
- struct drm_i915_private *dev_priv)
-{
- int ret;
-
- so->gen = INTEL_GEN(dev_priv);
- so->ggtt_offset = 0; /* keep gcc quiet */
- so->rodata = render_state_get_rodata(so->gen);
- if (so->rodata == NULL)
- return 0;
-
- if (so->rodata->batch_items * 4 > 4096)
- return -EINVAL;
-
- so->obj = i915_gem_object_create(&dev_priv->drm, 4096);
- if (IS_ERR(so->obj))
- return PTR_ERR(so->obj);
-
- ret = i915_gem_obj_ggtt_pin(so->obj, 4096, 0);
- if (ret)
- goto free_gem;
-
- so->ggtt_offset = i915_gem_obj_ggtt_offset(so->obj);
- return 0;
-
-free_gem:
- i915_gem_object_put(so->obj);
- return ret;
-}
-
/*
* Macro to add commands to auxiliary batch.
* This macro only checks for page overflow before inserting the commands,
@@ -106,6 +75,7 @@ static int render_state_setup(struct render_state *so)
{
struct drm_device *dev = so->obj->base.dev;
const struct intel_renderstate_rodata *rodata = so->rodata;
+ const bool has_64bit_reloc = INTEL_GEN(dev) >= 8;
unsigned int i = 0, reloc_index = 0;
struct page *page;
u32 *d;
@@ -124,7 +94,7 @@ static int render_state_setup(struct render_state *so)
if (i * 4 == rodata->reloc[reloc_index]) {
u64 r = s + so->ggtt_offset;
s = lower_32_bits(r);
- if (so->gen >= 8) {
+ if (has_64bit_reloc) {
if (i + 1 >= rodata->batch_items ||
rodata->batch[i + 1] != 0) {
ret = -EINVAL;
@@ -202,53 +172,40 @@ err_out:

#undef OUT_BATCH

-static void render_state_fini(struct render_state *so)
-{
- i915_gem_object_ggtt_unpin(so->obj);
- i915_gem_object_put(so->obj);
-}
-
-static int render_state_prepare(struct intel_engine_cs *engine,
- struct render_state *so)
+int i915_gem_render_state_init(struct drm_i915_gem_request *req)
{
+ struct render_state so;
int ret;

- if (WARN_ON(engine->id != RCS))
- return -ENOENT;
-
- ret = render_state_init(so, engine->i915);
- if (ret)
- return ret;
-
- if (so->rodata == NULL)
+ if (WARN_ON(req->engine->id != RCS))
return 0;

- ret = render_state_setup(so);
- if (ret) {
- render_state_fini(so);
- return ret;
- }
+ so.rodata = render_state_get_rodata(INTEL_GEN(req->i915));
+ if (so.rodata == NULL)
+ return 0;

- return 0;
-}
+ if (so.rodata->batch_items * 4 > 4096)
+ return -EINVAL;

-int i915_gem_render_state_init(struct drm_i915_gem_request *req)
-{
- struct render_state so;
- int ret;
+ so.obj = i915_gem_object_create(&req->i915->drm, 4096);
+ if (IS_ERR(so.obj))
+ return PTR_ERR(so.obj);

- ret = render_state_prepare(req->engine, &so);
+ ret = i915_gem_obj_ggtt_pin(so.obj, 4096, 0);
if (ret)
- return ret;
+ goto err_obj;

- if (so.rodata == NULL)
- return 0;
+ so.ggtt_offset = i915_gem_obj_ggtt_offset(so.obj);
+
+ ret = render_state_setup(&so);
+ if (ret)
+ goto err_unpin;

ret = req->engine->emit_bb_start(req, so.ggtt_offset,
so.rodata->batch_items * 4,
I915_DISPATCH_SECURE);
if (ret)
- goto out;
+ goto err_unpin;

if (so.aux_batch_size > 8) {
ret = req->engine->emit_bb_start(req,
@@ -257,11 +214,13 @@ int i915_gem_render_state_init(struct drm_i915_gem_request *req)
so.aux_batch_size,
I915_DISPATCH_SECURE);
if (ret)
- goto out;
+ goto err_unpin;
}

i915_vma_move_to_active(i915_gem_obj_to_ggtt(so.obj), req);
-out:
- render_state_fini(&so);
+err_unpin:
+ i915_gem_object_ggtt_unpin(so.obj);
+err_obj:
+ i915_gem_object_put(so.obj);
return ret;
}
--
2.8.1