[PATCH v2 09/11] drm/i915: Remove cs based page flip support.

Maarten Lankhorst
2016-04-13T09:18:22Z

With mmio flips now available on all platforms it's time to remove
support for cs flips.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
---
drivers/gpu/drm/i915/i915_debugfs.c | 21 +--
drivers/gpu/drm/i915/intel_display.c | 273 +----------------------------------
drivers/gpu/drm/i915/intel_drv.h | 6 +-
3 files changed, 12 insertions(+), 288 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 04ea4129c9f5..ccc390b10258 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -566,7 +566,6 @@ static void i915_dump_pageflip(struct seq_file *m,
{
const char pipe = pipe_name(crtc->pipe);
u32 pending;
- u32 addr;
int i;

pending = atomic_read(&work->pending);
@@ -578,7 +577,6 @@ static void i915_dump_pageflip(struct seq_file *m,
pipe, plane_name(crtc->plane));
}

-
for (i = 0; i < work->num_planes; i++) {
struct intel_plane_state *old_plane_state = work->old_plane_state[i];
struct drm_plane *plane = old_plane_state->base.plane;
@@ -602,22 +600,9 @@ static void i915_dump_pageflip(struct seq_file *m,
i915_gem_request_completed(req, true));
}

- seq_printf(m, "Flip queued on frame %d, (was ready on frame %d), now %d\n",
- work->flip_queued_vblank,
- work->flip_ready_vblank,
- drm_crtc_vblank_count(&crtc->base));
- seq_printf(m, "%d prepares\n", atomic_read(&work->pending));
-
- if (INTEL_INFO(dev_priv)->gen >= 4)
- addr = I915_HI_DISPBASE(I915_READ(DSPSURF(crtc->plane)));
- else
- addr = I915_READ(DSPADDR(crtc->plane));
- seq_printf(m, "Current scanout address 0x%08x\n", addr);
-
- if (work->flip_queued_req) {
- seq_printf(m, "New framebuffer address 0x%08lx\n", (long)work->gtt_offset);
- seq_printf(m, "MMIO update completed? %d\n", addr == work->gtt_offset);
- }
+ seq_printf(m, "Flip queued on frame %d, now %d\n",
+ pending ? work->flip_queued_vblank : -1,
+ intel_crtc_get_vblank_counter(crtc));
}

static int i915_gem_pageflip_info(struct seq_file *m, void *data)
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 2a8392ada270..45fd84ebaccf 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -48,11 +48,6 @@
#include <linux/reservation.h>
#include <linux/dma-buf.h>

-static bool is_mmio_work(struct intel_flip_work *work)
-{
- return !work->flip_queued_req;
-}
-
/* Primary plane formats for gen <= 3 */
static const uint32_t i8xx_primary_formats[] = {
DRM_FORMAT_C8,
@@ -3906,21 +3901,7 @@ static int intel_crtc_wait_for_pending_flips(struct drm_crtc *crtc)
if (ret < 0)
return ret;

- if (ret == 0) {
- struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
- struct intel_flip_work *work;
-
- spin_lock_irq(&dev->event_lock);
- work = list_first_entry_or_null(&intel_crtc->flip_work,
- struct intel_flip_work, head);
-
- if (work && !is_mmio_work(work) &&
- !work_busy(&work->unpin_work)) {
- WARN_ONCE(1, "Removing stuck page flip\n");
- page_flip_completed(intel_crtc, work);
- }
- spin_unlock_irq(&dev->event_lock);
- }
+ WARN(ret == 0, "Stuck page flip\n");

return 0;
}
@@ -10981,9 +10962,6 @@ static void intel_unpin_work_fn(struct work_struct *__work)

intel_crtc_destroy_state(crtc, &work->old_crtc_state->base);

- if (work->flip_queued_req)
- i915_gem_request_unreference__unlocked(work->flip_queued_req);
-
for (i = 0; i < work->num_planes; i++) {
struct intel_plane_state *old_plane_state =
work->old_plane_state[i];
@@ -11015,59 +10993,6 @@ static void intel_unpin_work_fn(struct work_struct *__work)
kfree(work);
}

-/* Is 'a' after or equal to 'b'? */
-static bool g4x_flip_count_after_eq(u32 a, u32 b)
-{
- return !((a - b) & 0x80000000);
-}
-
-static bool page_flip_finished(struct intel_crtc *crtc,
- struct intel_flip_work *work)
-{
- struct drm_device *dev = crtc->base.dev;
- struct drm_i915_private *dev_priv = dev->dev_private;
-
- if (i915_reset_in_progress(&dev_priv->gpu_error) ||
- crtc->reset_counter != atomic_read(&dev_priv->gpu_error.reset_counter))
- return true;
-
- /*
- * The relevant registers doen't exist on pre-ctg.
- * As the flip done interrupt doesn't trigger for mmio
- * flips on gmch platforms, a flip count check isn't
- * really needed there. But since ctg has the registers,
- * include it in the check anyway.
- */
- if (INTEL_INFO(dev)->gen < 5 && !IS_G4X(dev))
- return true;
-
- /*
- * BDW signals flip done immediately if the plane
- * is disabled, even if the plane enable is already
- * armed to occur at the next vblank :(
- */
-
- /*
- * A DSPSURFLIVE check isn't enough in case the mmio and CS flips
- * used the same base address. In that case the mmio flip might
- * have completed, but the CS hasn't even executed the flip yet.
- *
- * A flip count check isn't enough as the CS might have updated
- * the base address just after start of vblank, but before we
- * managed to process the interrupt. This means we'd complete the
- * CS flip too soon.
- *
- * Combining both checks should get us a good enough result. It may
- * still happen that the CS flip has been executed, but has not
- * yet actually completed. But in case the base address is the same
- * anyway, we don't really care.
- */
- return (I915_READ(DSPSURFLIVE(crtc->plane)) & ~0xfff) ==
- work->gtt_offset &&
- g4x_flip_count_after_eq(I915_READ(PIPE_FLIPCOUNT_G4X(crtc->pipe)),
- work->flip_count);
-}
-
static void do_intel_finish_page_flip(struct drm_device *dev,
struct drm_crtc *crtc)
{
@@ -11090,7 +11015,7 @@ static void do_intel_finish_page_flip(struct drm_device *dev,

if (work == NULL ||
atomic_read(&work->pending) == INTEL_FLIP_INACTIVE ||
- !page_flip_finished(intel_crtc, work) || work_busy(&work->unpin_work)) {
+ work_busy(&work->unpin_work)) {
spin_unlock_irqrestore(&dev->event_lock, flags);
return;
}
@@ -11347,153 +11272,6 @@ static int intel_gen7_queue_flip(struct drm_device *dev,
return 0;
}

-static struct intel_engine_cs *
-intel_get_flip_engine(struct drm_device *dev,
- struct drm_i915_private *dev_priv,
- struct drm_i915_gem_object *obj)
-{
- if (IS_VALLEYVIEW(dev) || IS_IVYBRIDGE(dev) || IS_HASWELL(dev))
- return &dev_priv->engine[BCS];
-
- if (dev_priv->info.gen >= 7) {
- struct intel_engine_cs *engine;
-
- engine = i915_gem_request_get_engine(obj->last_write_req);
- if (engine && engine->id == RCS)
- return engine;
-
- return &dev_priv->engine[BCS];
- } else
- return &dev_priv->engine[RCS];
-}
-
-static bool
-flip_fb_compatible(struct drm_device *dev,
- struct drm_framebuffer *fb,
- struct drm_framebuffer *old_fb)
-{
- struct drm_i915_gem_object *obj = intel_fb_obj(fb);
- struct drm_i915_gem_object *old_obj = intel_fb_obj(old_fb);
-
- if (old_fb->pixel_format != fb->pixel_format)
- return false;
-
- if (INTEL_INFO(dev)->gen > 3 &&
- (fb->offsets[0] != old_fb->offsets[0] ||
- fb->pitches[0] != old_fb->pitches[0]))
- return false;
-
- /* vlv: DISPLAY_FLIP fails to change tiling */
- if (IS_VALLEYVIEW(dev) && obj->tiling_mode != old_obj->tiling_mode)
- return false;
-
- return true;
-}
-
-static void
-intel_display_flip_prepare(struct drm_device *dev, struct drm_crtc *crtc,
- struct intel_flip_work *work)
-{
- struct drm_i915_private *dev_priv = dev->dev_private;
- struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
-
- if (work->flip_prepared)
- return;
-
- work->flip_prepared = true;
-
- if (INTEL_INFO(dev)->gen >= 5 || IS_G4X(dev))
- work->flip_count = I915_READ(PIPE_FLIPCOUNT_G4X(intel_crtc->pipe)) + 1;
- work->flip_queued_vblank = drm_crtc_vblank_count(crtc);
-
- intel_frontbuffer_flip_prepare(dev, work->new_crtc_state->fb_bits);
-}
-
-static void intel_flip_schedule_request(struct intel_flip_work *work, struct drm_crtc *crtc)
-{
- struct drm_device *dev = crtc->dev;
- struct drm_i915_private *dev_priv = dev->dev_private;
- struct intel_plane_state *new_state = work->new_plane_state[0];
- struct intel_plane_state *old_state = work->old_plane_state[0];
- struct drm_framebuffer *fb, *old_fb;
- struct drm_i915_gem_request *request = NULL;
- struct intel_engine_cs *engine;
- struct drm_i915_gem_object *obj;
- struct fence *fence;
- int ret;
-
- if (i915_terminally_wedged(&dev_priv->gpu_error) ||
- i915_reset_in_progress(&dev_priv->gpu_error) ||
- i915.enable_execlists || i915.use_mmio_flip > 0 ||
- !dev_priv->display.queue_flip)
- goto mmio;
-
- /* Not right after modesetting, surface parameters need to be updated */
- if (needs_modeset(crtc->state) ||
- to_intel_crtc_state(crtc->state)->update_pipe)
- goto mmio;
-
- /* Only allow a mmio flip for a primary plane without a dma-buf fence */
- if (work->num_planes != 1 ||
- new_state->base.plane != crtc->primary ||
- new_state->base.fence)
- goto mmio;
-
- fence = work->old_plane_state[0]->base.fence;
- if (fence && !fence_is_signaled(fence))
- goto mmio;
-
- old_fb = old_state->base.fb;
- fb = new_state->base.fb;
- obj = intel_fb_obj(fb);
-
- trace_i915_flip_request(to_intel_crtc(crtc)->plane, obj);
-
- /* Only when updating a already visible fb. */
- if (!new_state->visible || !old_state->visible)
- goto mmio;
-
- if (!flip_fb_compatible(dev, fb, old_fb))
- goto mmio;
-
- engine = intel_get_flip_engine(dev, dev_priv, obj);
- if (i915.use_mmio_flip == 0 && obj->last_write_req &&
- i915_gem_request_get_engine(obj->last_write_req) != engine)
- goto mmio;
-
- work->gtt_offset = intel_plane_obj_offset(to_intel_plane(crtc->primary), obj, 0);
- work->gtt_offset += to_intel_crtc(crtc)->dspaddr_offset;
-
- ret = i915_gem_object_sync(obj, engine, &request);
- if (!ret && !request) {
- request = i915_gem_request_alloc(engine, NULL);
- ret = PTR_ERR_OR_ZERO(request);
-
- if (ret)
- request = NULL;
- }
-
- intel_display_flip_prepare(dev, crtc, work);
-
- if (!ret)
- ret = dev_priv->display.queue_flip(dev, crtc, fb, obj, request, 0);
-
- if (!ret) {
- i915_gem_request_assign(&work->flip_queued_req, request);
- smp_mb__before_atomic();
- atomic_set(&work->pending, INTEL_FLIP_PENDING);
- i915_add_request_no_flush(request);
- return;
- }
- if (request)
- i915_gem_request_cancel(request);
-
-mmio:
- to_intel_crtc(crtc)->reset_counter =
- atomic_read(&dev_priv->gpu_error.reset_counter);
- schedule_work(&work->mmio_work);
-}
-
static void intel_mmio_flip_work_func(struct work_struct *w)
{
struct intel_flip_work *work =
@@ -11522,7 +11300,7 @@ static void intel_mmio_flip_work_func(struct work_struct *w)
&dev_priv->rps.mmioflips));
}

- intel_display_flip_prepare(dev, crtc, work);
+ intel_frontbuffer_flip_prepare(dev, crtc_state->fb_bits);

intel_pipe_update_start(intel_crtc);
if (!needs_modeset(&crtc_state->base)) {
@@ -11551,9 +11329,7 @@ static bool __intel_pageflip_stall_check(struct drm_device *dev,
struct drm_crtc *crtc,
struct intel_flip_work *work)
{
- struct drm_i915_private *dev_priv = dev->dev_private;
struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
- u32 addr;
u32 pending;

pending = atomic_read(&work->pending);
@@ -11563,36 +11339,8 @@ static bool __intel_pageflip_stall_check(struct drm_device *dev,

smp_mb__after_atomic();

- if (is_mmio_work(work)) {
- u32 cur = intel_crtc_get_vblank_counter(intel_crtc);
-
- /* MMIO work completes when vblank is different from flip_queued_vblank. */
- return cur != work->flip_queued_vblank;
- }
-
- if (work->flip_ready_vblank == 0) {
- if (work->flip_queued_req &&
- !i915_gem_request_completed(work->flip_queued_req, true))
- return false;
-
- work->flip_ready_vblank = drm_crtc_vblank_count(crtc);
- }
-
- if (drm_crtc_vblank_count(crtc) - work->flip_ready_vblank < 3)
- return false;
-
- /* Potential stall - if we see that the flip has happened,
- * assume a missed interrupt. */
- if (INTEL_INFO(dev)->gen >= 4)
- addr = I915_HI_DISPBASE(I915_READ(DSPSURF(intel_crtc->plane)));
- else
- addr = I915_READ(DSPADDR(intel_crtc->plane));
-
- /* There is a potential issue here with a false positive after a flip
- * to the same address. We could address this by checking for a
- * non-incrementing frame counter.
- */
- return addr == work->gtt_offset;
+ /* MMIO work completes when vblank is different from flip_queued_vblank. */
+ return work->flip_queued_vblank != intel_crtc_get_vblank_counter(intel_crtc);
}

void intel_check_page_flip(struct drm_device *dev, int pipe)
@@ -11612,15 +11360,8 @@ void intel_check_page_flip(struct drm_device *dev, int pipe)
struct intel_flip_work, head);

if (work != NULL && __intel_pageflip_stall_check(dev, crtc, work)) {
- WARN_ONCE(!is_mmio_work(work),
- "Kicking stuck page flip: queued at %d, now %d\n",
- work->flip_queued_vblank, drm_vblank_count(dev, pipe));
page_flip_completed(intel_crtc, work);
- work = NULL;
}
- if (work != NULL && !is_mmio_work(work) &&
- drm_vblank_count(dev, pipe) - work->flip_queued_vblank > 1)
- intel_queue_rps_boost_for_request(dev, work->flip_queued_req);
spin_unlock(&dev->event_lock);
}

@@ -11787,7 +11528,9 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,

intel_fbc_pre_update(intel_crtc);

- intel_flip_schedule_request(work, crtc);
+ intel_crtc->reset_counter =
+ atomic_read(&dev_priv->gpu_error.reset_counter);
+ schedule_work(&work->mmio_work);

mutex_unlock(&dev->struct_mutex);

diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 7ecebf0c22e0..02ea5adfda72 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -939,16 +939,12 @@ struct intel_flip_work {
atomic_t pending;
#define INTEL_FLIP_INACTIVE 0
#define INTEL_FLIP_PENDING 1
- u32 flip_count;
- u32 gtt_offset;
- struct drm_i915_gem_request *flip_queued_req;
u32 flip_queued_vblank;
- u32 flip_ready_vblank;

unsigned put_power_domains;
unsigned num_planes;

- bool can_async_unpin, flip_prepared;
+ bool can_async_unpin;
unsigned fb_bits;

struct intel_crtc_state *old_crtc_state, *new_crtc_state;