1 files changed, 271 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/display/hsw_ips.c b/drivers/gpu/drm/i915/display/hsw_ips.c
new file mode 100644
index 000000000000..38014e0cc9ad
--- /dev/null
+++ b/drivers/gpu/drm/i915/display/hsw_ips.c
@@ -0,0 +1,271 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2022 Intel Corporation
+ */
+
+#include "hsw_ips.h"
+#include "i915_drv.h"
+#include "i915_reg.h"
+#include "intel_de.h"
+#include "intel_display_types.h"
+#include "intel_pcode.h"
+
+static void hsw_ips_enable(const struct intel_crtc_state *crtc_state)
+{
+	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
+	struct drm_i915_private *i915 = to_i915(crtc->base.dev);
+
+	if (!crtc_state->ips_enabled)
+		return;
+
+	/*
+	 * We can only enable IPS after we enable a plane and wait for a vblank
+	 * This function is called from post_plane_update, which is run after
+	 * a vblank wait.
+	 */
+	drm_WARN_ON(&i915->drm,
+		    !(crtc_state->active_planes & ~BIT(PLANE_CURSOR)));
+
+	if (IS_BROADWELL(i915)) {
+		drm_WARN_ON(&i915->drm,
+			    snb_pcode_write(i915, DISPLAY_IPS_CONTROL,
+					    IPS_ENABLE | IPS_PCODE_CONTROL));
+		/*
+		 * Quoting Art Runyan: "its not safe to expect any particular
+		 * value in IPS_CTL bit 31 after enabling IPS through the
+		 * mailbox." Moreover, the mailbox may return a bogus state,
+		 * so we need to just enable it and continue on.
+		 */
+	} else {
+		intel_de_write(i915, IPS_CTL, IPS_ENABLE);
+		/*
+		 * The bit only becomes 1 in the next vblank, so this wait here
+		 * is essentially intel_wait_for_vblank. If we don't have this
+		 * and don't wait for vblanks until the end of crtc_enable, then
+		 * the HW state readout code will complain that the expected
+		 * IPS_CTL value is not the one we read.
+		 */
+		if (intel_de_wait_for_set(i915, IPS_CTL, IPS_ENABLE, 50))
+			drm_err(&i915->drm,
+				"Timed out waiting for IPS enable\n");
+	}
+}
+
+bool hsw_ips_disable(const struct intel_crtc_state *crtc_state)
+{
+	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
+	struct drm_i915_private *i915 = to_i915(crtc->base.dev);
+	bool need_vblank_wait = false;
+
+	if (!crtc_state->ips_enabled)
+		return need_vblank_wait;
+
+	if (IS_BROADWELL(i915)) {
+		drm_WARN_ON(&i915->drm,
+			    snb_pcode_write(i915, DISPLAY_IPS_CONTROL, 0));
+		/*
+		 * Wait for PCODE to finish disabling IPS. The BSpec specified
+		 * 42ms timeout value leads to occasional timeouts so use 100ms
+		 * instead.
+		 */
+		if (intel_de_wait_for_clear(i915, IPS_CTL, IPS_ENABLE, 100))
+			drm_err(&i915->drm,
+				"Timed out waiting for IPS disable\n");
+	} else {
+		intel_de_write(i915, IPS_CTL, 0);
+		intel_de_posting_read(i915, IPS_CTL);
+	}
+
+	/* We need to wait for a vblank before we can disable the plane. */
+	need_vblank_wait = true;
+
+	return need_vblank_wait;
+}
+
+static bool hsw_ips_need_disable(struct intel_atomic_state *state,
+				 struct intel_crtc *crtc)
+{
+	struct drm_i915_private *i915 = to_i915(state->base.dev);
+	const struct intel_crtc_state *old_crtc_state =
+		intel_atomic_get_old_crtc_state(state, crtc);
+	const struct intel_crtc_state *new_crtc_state =
+		intel_atomic_get_new_crtc_state(state, crtc);
+
+	if (!old_crtc_state->ips_enabled)
+		return false;
+
+	if (intel_crtc_needs_modeset(new_crtc_state))
+		return true;
+
+	/*
+	 * Workaround : Do not read or write the pipe palette/gamma data while
+	 * GAMMA_MODE is configured for split gamma and IPS_CTL has IPS enabled.
+	 *
+	 * Disable IPS before we program the LUT.
+	 */
+	if (IS_HASWELL(i915) &&
+	    (new_crtc_state->uapi.color_mgmt_changed ||
+	     new_crtc_state->update_pipe) &&
+	    new_crtc_state->gamma_mode == GAMMA_MODE_MODE_SPLIT)
+		return true;
+
+	return !new_crtc_state->ips_enabled;
+}
+
+bool hsw_ips_pre_update(struct intel_atomic_state *state,
+			struct intel_crtc *crtc)
+{
+	const struct intel_crtc_state *old_crtc_state =
+		intel_atomic_get_old_crtc_state(state, crtc);
+
+	if (!hsw_ips_need_disable(state, crtc))
+		return false;
+
+	return hsw_ips_disable(old_crtc_state);
+}
+
+static bool hsw_ips_need_enable(struct intel_atomic_state *state,
+				struct intel_crtc *crtc)
+{
+	struct drm_i915_private *i915 = to_i915(state->base.dev);
+	const struct intel_crtc_state *old_crtc_state =
+		intel_atomic_get_old_crtc_state(state, crtc);
+	const struct intel_crtc_state *new_crtc_state =
+		intel_atomic_get_new_crtc_state(state, crtc);
+
+	if (!new_crtc_state->ips_enabled)
+		return false;
+
+	if (intel_crtc_needs_modeset(new_crtc_state))
+		return true;
+
+	/*
+	 * Workaround : Do not read or write the pipe palette/gamma data while
+	 * GAMMA_MODE is configured for split gamma and IPS_CTL has IPS enabled.
+	 *
+	 * Re-enable IPS after the LUT has been programmed.
+	 */
+	if (IS_HASWELL(i915) &&
+	    (new_crtc_state->uapi.color_mgmt_changed ||
+	     new_crtc_state->update_pipe) &&
+	    new_crtc_state->gamma_mode == GAMMA_MODE_MODE_SPLIT)
+		return true;
+
+	/*
+	 * We can't read out IPS on broadwell, assume the worst and
+	 * forcibly enable IPS on the first fastset.
+	 */
+	if (new_crtc_state->update_pipe && old_crtc_state->inherited)
+		return true;
+
+	return !old_crtc_state->ips_enabled;
+}
+
+void hsw_ips_post_update(struct intel_atomic_state *state,
+			 struct intel_crtc *crtc)
+{
+	const struct intel_crtc_state *new_crtc_state =
+		intel_atomic_get_new_crtc_state(state, crtc);
+
+	if (!hsw_ips_need_enable(state, crtc))
+		return;
+
+	hsw_ips_enable(new_crtc_state);
+}
+
+/* IPS only exists on ULT machines and is tied to pipe A. */
+bool hsw_crtc_supports_ips(struct intel_crtc *crtc)
+{
+	return HAS_IPS(to_i915(crtc->base.dev)) && crtc->pipe == PIPE_A;
+}
+
+bool hsw_crtc_state_ips_capable(const struct intel_crtc_state *crtc_state)
+{
+	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
+	struct drm_i915_private *i915 = to_i915(crtc->base.dev);
+
+	/* IPS only exists on ULT machines and is tied to pipe A. */
+	if (!hsw_crtc_supports_ips(crtc))
+		return false;
+
+	if (!i915->params.enable_ips)
+		return false;
+
+	if (crtc_state->pipe_bpp > 24)
+		return false;
+
+	/*
+	 * We compare against max which means we must take
+	 * the increased cdclk requirement into account when
+	 * calculating the new cdclk.
+	 *
+	 * Should measure whether using a lower cdclk w/o IPS
+	 */
+	if (IS_BROADWELL(i915) &&
+	    crtc_state->pixel_rate > i915->max_cdclk_freq * 95 / 100)
+		return false;
+
+	return true;
+}
+
+int hsw_ips_compute_config(struct intel_atomic_state *state,
+			   struct intel_crtc *crtc)
+{
+	struct drm_i915_private *i915 = to_i915(state->base.dev);
+	struct intel_crtc_state *crtc_state =
+		intel_atomic_get_new_crtc_state(state, crtc);
+
+	crtc_state->ips_enabled = false;
+
+	if (!hsw_crtc_state_ips_capable(crtc_state))
+		return 0;
+
+	/*
+	 * When IPS gets enabled, the pipe CRC changes. Since IPS gets
+	 * enabled and disabled dynamically based on package C states,
+	 * user space can't make reliable use of the CRCs, so let's just
+	 * completely disable it.
+	 */
+	if (crtc_state->crc_enabled)
+		return 0;
+
+	/* IPS should be fine as long as at least one plane is enabled. */
+	if (!(crtc_state->active_planes & ~BIT(PLANE_CURSOR)))
+		return 0;
+
+	if (IS_BROADWELL(i915)) {
+		const struct intel_cdclk_state *cdclk_state;
+
+		cdclk_state = intel_atomic_get_cdclk_state(state);
+		if (IS_ERR(cdclk_state))
+			return PTR_ERR(cdclk_state);
+
+		/* pixel rate mustn't exceed 95% of cdclk with IPS on BDW */
+		if (crtc_state->pixel_rate > cdclk_state->logical.cdclk * 95 / 100)
+			return 0;
+	}
+
+	crtc_state->ips_enabled = true;
+
+	return 0;
+}
+
+void hsw_ips_get_config(struct intel_crtc_state *crtc_state)
+{
+	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
+	struct drm_i915_private *i915 = to_i915(crtc->base.dev);
+
+	if (!hsw_crtc_supports_ips(crtc))
+		return;
+
+	if (IS_HASWELL(i915)) {
+		crtc_state->ips_enabled = intel_de_read(i915, IPS_CTL) & IPS_ENABLE;
+	} else {
+		/*
+		 * We cannot readout IPS state on broadwell, set to
+		 * true so we can set it to a defined state on first
+		 * commit.
+		 */
+		crtc_state->ips_enabled = true;
+	}
+}