drm/i915/display: add intel_display_reset.[ch]

Split out the display reset functionality to a separate file to
declutter intel_display.c. Rename the functions accordingly. The minor
downside is having to expose __intel_display_resume().

Reviewed-by: Gustavo Sousa <gustavo.sousa@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/5e98e2fc5f0c09490e02d22250c8201342852288.1681465222.git.jani.nikula@intel.com

1 files changed, 135 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/display/intel_display_reset.c b/drivers/gpu/drm/i915/display/intel_display_reset.c
new file mode 100644
index 000000000000..166aa0cab1fc
--- /dev/null
+++ b/drivers/gpu/drm/i915/display/intel_display_reset.c
@@ -0,0 +1,135 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2023 Intel Corporation
+ */
+
+#include <drm/drm_atomic_helper.h>
+
+#include "i915_drv.h"
+#include "intel_clock_gating.h"
+#include "intel_display_driver.h"
+#include "intel_display_reset.h"
+#include "intel_display_types.h"
+#include "intel_hotplug.h"
+#include "intel_pps.h"
+
+static bool gpu_reset_clobbers_display(struct drm_i915_private *dev_priv)
+{
+	return (INTEL_INFO(dev_priv)->gpu_reset_clobbers_display &&
+		intel_has_gpu_reset(to_gt(dev_priv)));
+}
+
+void intel_display_reset_prepare(struct drm_i915_private *dev_priv)
+{
+	struct drm_modeset_acquire_ctx *ctx = &dev_priv->display.restore.reset_ctx;
+	struct drm_atomic_state *state;
+	int ret;
+
+	if (!HAS_DISPLAY(dev_priv))
+		return;
+
+	/* reset doesn't touch the display */
+	if (!dev_priv->params.force_reset_modeset_test &&
+	    !gpu_reset_clobbers_display(dev_priv))
+		return;
+
+	/* We have a modeset vs reset deadlock, defensively unbreak it. */
+	set_bit(I915_RESET_MODESET, &to_gt(dev_priv)->reset.flags);
+	smp_mb__after_atomic();
+	wake_up_bit(&to_gt(dev_priv)->reset.flags, I915_RESET_MODESET);
+
+	if (atomic_read(&dev_priv->gpu_error.pending_fb_pin)) {
+		drm_dbg_kms(&dev_priv->drm,
+			    "Modeset potentially stuck, unbreaking through wedging\n");
+		intel_gt_set_wedged(to_gt(dev_priv));
+	}
+
+	/*
+	 * Need mode_config.mutex so that we don't
+	 * trample ongoing ->detect() and whatnot.
+	 */
+	mutex_lock(&dev_priv->drm.mode_config.mutex);
+	drm_modeset_acquire_init(ctx, 0);
+	while (1) {
+		ret = drm_modeset_lock_all_ctx(&dev_priv->drm, ctx);
+		if (ret != -EDEADLK)
+			break;
+
+		drm_modeset_backoff(ctx);
+	}
+	/*
+	 * Disabling the crtcs gracefully seems nicer. Also the
+	 * g33 docs say we should at least disable all the planes.
+	 */
+	state = drm_atomic_helper_duplicate_state(&dev_priv->drm, ctx);
+	if (IS_ERR(state)) {
+		ret = PTR_ERR(state);
+		drm_err(&dev_priv->drm, "Duplicating state failed with %i\n",
+			ret);
+		return;
+	}
+
+	ret = drm_atomic_helper_disable_all(&dev_priv->drm, ctx);
+	if (ret) {
+		drm_err(&dev_priv->drm, "Suspending crtc's failed with %i\n",
+			ret);
+		drm_atomic_state_put(state);
+		return;
+	}
+
+	dev_priv->display.restore.modeset_state = state;
+	state->acquire_ctx = ctx;
+}
+
+void intel_display_reset_finish(struct drm_i915_private *i915)
+{
+	struct drm_modeset_acquire_ctx *ctx = &i915->display.restore.reset_ctx;
+	struct drm_atomic_state *state;
+	int ret;
+
+	if (!HAS_DISPLAY(i915))
+		return;
+
+	/* reset doesn't touch the display */
+	if (!test_bit(I915_RESET_MODESET, &to_gt(i915)->reset.flags))
+		return;
+
+	state = fetch_and_zero(&i915->display.restore.modeset_state);
+	if (!state)
+		goto unlock;
+
+	/* reset doesn't touch the display */
+	if (!gpu_reset_clobbers_display(i915)) {
+		/* for testing only restore the display */
+		ret = drm_atomic_helper_commit_duplicated_state(state, ctx);
+		if (ret) {
+			drm_WARN_ON(&i915->drm, ret == -EDEADLK);
+			drm_err(&i915->drm,
+				"Restoring old state failed with %i\n", ret);
+		}
+	} else {
+		/*
+		 * The display has been reset as well,
+		 * so need a full re-initialization.
+		 */
+		intel_pps_unlock_regs_wa(i915);
+		intel_display_driver_init_hw(i915);
+		intel_clock_gating_init(i915);
+		intel_hpd_init(i915);
+
+		ret = __intel_display_resume(i915, state, ctx);
+		if (ret)
+			drm_err(&i915->drm,
+				"Restoring old state failed with %i\n", ret);
+
+		intel_hpd_poll_disable(i915);
+	}
+
+	drm_atomic_state_put(state);
+unlock:
+	drm_modeset_drop_locks(ctx);
+	drm_modeset_acquire_fini(ctx);
+	mutex_unlock(&i915->drm.mode_config.mutex);
+
+	clear_bit_unlock(I915_RESET_MODESET, &to_gt(i915)->reset.flags);
+}