[src/trunk]: src/sys/external/bsd/drm2/dist/drm/i915 i915: Rework atomic comm...

[riastradh <riastradh%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/135d859ad501
branches:  trunk
changeset: 1028746:135d859ad501
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Sun Dec 19 11:55:24 2021 +0000

description:
i915: Rework atomic commit wakeups to work with condvars.

Lock order is intel_state->commit_ready.wait.lock then
dev_priv->atomic_commit_lock.

diffstat:

 sys/external/bsd/drm2/dist/drm/i915/display/intel_display.c |  72 +++++++-----
 sys/external/bsd/drm2/dist/drm/i915/i915_drv.h              |   5 +-
 2 files changed, 45 insertions(+), 32 deletions(-)

diffs (122 lines):

diff -r 204f14696298 -r 135d859ad501 sys/external/bsd/drm2/dist/drm/i915/display/intel_display.c
--- a/sys/external/bsd/drm2/dist/drm/i915/display/intel_display.c       Sun Dec 19 11:55:07 2021 +0000
+++ b/sys/external/bsd/drm2/dist/drm/i915/display/intel_display.c       Sun Dec 19 11:55:24 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: intel_display.c,v 1.4 2021/12/19 11:55:07 riastradh Exp $      */
+/*     $NetBSD: intel_display.c,v 1.5 2021/12/19 11:55:24 riastradh Exp $      */
 
 /*
  * Copyright © 2006-2007 Intel Corporation
@@ -27,7 +27,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: intel_display.c,v 1.4 2021/12/19 11:55:07 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: intel_display.c,v 1.5 2021/12/19 11:55:24 riastradh Exp $");
 
 #include "intel_display.h"     /* for pipe_drmhack */
 
@@ -4823,9 +4823,11 @@
                return;
 
        /* We have a modeset vs reset deadlock, defensively unbreak it. */
+       spin_lock(&dev_priv->atomic_commit_lock);
        set_bit(I915_RESET_MODESET, &dev_priv->gt.reset.flags);
-       smp_mb__after_atomic();
-       wake_up_bit(&dev_priv->gt.reset.flags, I915_RESET_MODESET);
+       DRM_SPIN_WAKEUP_ALL(&dev_priv->atomic_commit_wq,
+           &dev_priv->atomic_commit_lock);
+       spin_unlock(&dev_priv->atomic_commit_lock);
 
        if (atomic_read(&dev_priv->gpu_error.pending_fb_pin)) {
                DRM_DEBUG_KMS("Modeset potentially stuck, unbreaking through wedging\n");
@@ -15271,35 +15273,43 @@
        intel_atomic_helper_free_state(dev_priv);
 }
 
-static void intel_atomic_commit_fence_wait(struct intel_atomic_state *intel_state)
-{
-#ifdef __NetBSD__
-       panic("NYI");
-#else
-       struct wait_queue_entry wait_fence, wait_reset;
+static int
+intel_atomic_commit_fence_wake(struct i915_sw_fence_waiter *waiter,
+    unsigned mode, int flags, void *cookie)
+{
+       struct intel_atomic_state *intel_state = cookie;
        struct drm_i915_private *dev_priv = to_i915(intel_state->base.dev);
 
-       init_wait_entry(&wait_fence, 0);
-       init_wait_entry(&wait_reset, 0);
-       for (;;) {
-               prepare_to_wait(&intel_state->commit_ready.wait,
-                               &wait_fence, TASK_UNINTERRUPTIBLE);
-               prepare_to_wait(bit_waitqueue(&dev_priv->gt.reset.flags,
-                                             I915_RESET_MODESET),
-                               &wait_reset, TASK_UNINTERRUPTIBLE);
-
-
-               if (i915_sw_fence_done(&intel_state->commit_ready) ||
-                   test_bit(I915_RESET_MODESET, &dev_priv->gt.reset.flags))
-                       break;
-
-               schedule();
-       }
-       finish_wait(&intel_state->commit_ready.wait, &wait_fence);
-       finish_wait(bit_waitqueue(&dev_priv->gt.reset.flags,
-                                 I915_RESET_MODESET),
-                   &wait_reset);
-#endif
+       spin_lock(&dev_priv->atomic_commit_lock);
+       DRM_SPIN_WAKEUP_ALL(&dev_priv->atomic_commit_wq,
+           &dev_priv->atomic_commit_lock);
+       spin_unlock(&dev_priv->atomic_commit_lock);
+
+       list_del_init(&waiter->entry);
+
+       return 0;
+}
+
+static void intel_atomic_commit_fence_wait(struct intel_atomic_state *intel_state)
+{
+       struct drm_i915_private *dev_priv = to_i915(intel_state->base.dev);
+       struct i915_sw_fence_waiter waiter;
+       int ret;
+
+       waiter.flags = 0;
+       waiter.func = intel_atomic_commit_fence_wake;
+       waiter.private = intel_state;
+
+       spin_lock(&intel_state->commit_ready.wait.lock);
+       list_add_tail(&waiter.entry, &intel_state->commit_ready.wait.head);
+       spin_unlock(&intel_state->commit_ready.wait.lock);
+
+       spin_lock(&dev_priv->atomic_commit_lock);
+       DRM_SPIN_WAIT_NOINTR_UNTIL(ret, &dev_priv->atomic_commit_wq,
+           &dev_priv->atomic_commit_lock,
+           (i915_sw_fence_done(&intel_state->commit_ready) ||
+               test_bit(I915_RESET_MODESET, &dev_priv->gt.reset.flags)));
+       spin_unlock(&dev_priv->atomic_commit_lock);
 }
 
 static void intel_atomic_cleanup_work(struct work_struct *work)
diff -r 204f14696298 -r 135d859ad501 sys/external/bsd/drm2/dist/drm/i915/i915_drv.h
--- a/sys/external/bsd/drm2/dist/drm/i915/i915_drv.h    Sun Dec 19 11:55:07 2021 +0000
+++ b/sys/external/bsd/drm2/dist/drm/i915/i915_drv.h    Sun Dec 19 11:55:24 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: i915_drv.h,v 1.45 2021/12/19 11:51:59 riastradh Exp $  */
+/*     $NetBSD: i915_drv.h,v 1.46 2021/12/19 11:55:24 riastradh Exp $  */
 
 /* i915_drv.h -- Private header for the I915 driver -*- linux-c -*-
  */
@@ -1087,6 +1087,9 @@
        struct drm_atomic_state *modeset_restore_state;
        struct drm_modeset_acquire_ctx reset_ctx;
 
+       spinlock_t atomic_commit_lock;
+       drm_waitqueue_t atomic_commit_wq;
+
        struct i915_ggtt ggtt; /* VM representing the global address space */
 
        struct i915_gem_mm mm;