1 files changed, 266 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/vlv_sideband.c b/drivers/gpu/drm/i915/vlv_sideband.c
new file mode 100644
index 000000000..c26001300
--- /dev/null
+++ b/drivers/gpu/drm/i915/vlv_sideband.c
@@ -0,0 +1,266 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2013-2021 Intel Corporation
+ */
+
+#include "i915_drv.h"
+#include "i915_iosf_mbi.h"
+#include "i915_reg.h"
+#include "vlv_sideband.h"
+
+/*
+ * IOSF sideband, see VLV2_SidebandMsg_HAS.docx and
+ * VLV_VLV2_PUNIT_HAS_0.8.docx
+ */
+
+/* Standard MMIO read, non-posted */
+#define SB_MRD_NP	0x00
+/* Standard MMIO write, non-posted */
+#define SB_MWR_NP	0x01
+/* Private register read, double-word addressing, non-posted */
+#define SB_CRRDDA_NP	0x06
+/* Private register write, double-word addressing, non-posted */
+#define SB_CRWRDA_NP	0x07
+
+static void ping(void *info)
+{
+}
+
+static void __vlv_punit_get(struct drm_i915_private *i915)
+{
+	iosf_mbi_punit_acquire();
+
+	/*
+	 * Prevent the cpu from sleeping while we use this sideband, otherwise
+	 * the punit may cause a machine hang. The issue appears to be isolated
+	 * with changing the power state of the CPU package while changing
+	 * the power state via the punit, and we have only observed it
+	 * reliably on 4-core Baytail systems suggesting the issue is in the
+	 * power delivery mechanism and likely to be board/function
+	 * specific. Hence we presume the workaround needs only be applied
+	 * to the Valleyview P-unit and not all sideband communications.
+	 */
+	if (IS_VALLEYVIEW(i915)) {
+		cpu_latency_qos_update_request(&i915->sb_qos, 0);
+		on_each_cpu(ping, NULL, 1);
+	}
+}
+
+static void __vlv_punit_put(struct drm_i915_private *i915)
+{
+	if (IS_VALLEYVIEW(i915))
+		cpu_latency_qos_update_request(&i915->sb_qos,
+					       PM_QOS_DEFAULT_VALUE);
+
+	iosf_mbi_punit_release();
+}
+
+void vlv_iosf_sb_get(struct drm_i915_private *i915, unsigned long ports)
+{
+	if (ports & BIT(VLV_IOSF_SB_PUNIT))
+		__vlv_punit_get(i915);
+
+	mutex_lock(&i915->sb_lock);
+}
+
+void vlv_iosf_sb_put(struct drm_i915_private *i915, unsigned long ports)
+{
+	mutex_unlock(&i915->sb_lock);
+
+	if (ports & BIT(VLV_IOSF_SB_PUNIT))
+		__vlv_punit_put(i915);
+}
+
+static int vlv_sideband_rw(struct drm_i915_private *i915,
+			   u32 devfn, u32 port, u32 opcode,
+			   u32 addr, u32 *val)
+{
+	struct intel_uncore *uncore = &i915->uncore;
+	const bool is_read = (opcode == SB_MRD_NP || opcode == SB_CRRDDA_NP);
+	int err;
+
+	lockdep_assert_held(&i915->sb_lock);
+	if (port == IOSF_PORT_PUNIT)
+		iosf_mbi_assert_punit_acquired();
+
+	/* Flush the previous comms, just in case it failed last time. */
+	if (intel_wait_for_register(uncore,
+				    VLV_IOSF_DOORBELL_REQ, IOSF_SB_BUSY, 0,
+				    5)) {
+		drm_dbg(&i915->drm, "IOSF sideband idle wait (%s) timed out\n",
+			is_read ? "read" : "write");
+		return -EAGAIN;
+	}
+
+	preempt_disable();
+
+	intel_uncore_write_fw(uncore, VLV_IOSF_ADDR, addr);
+	intel_uncore_write_fw(uncore, VLV_IOSF_DATA, is_read ? 0 : *val);
+	intel_uncore_write_fw(uncore, VLV_IOSF_DOORBELL_REQ,
+			      (devfn << IOSF_DEVFN_SHIFT) |
+			      (opcode << IOSF_OPCODE_SHIFT) |
+			      (port << IOSF_PORT_SHIFT) |
+			      (0xf << IOSF_BYTE_ENABLES_SHIFT) |
+			      (0 << IOSF_BAR_SHIFT) |
+			      IOSF_SB_BUSY);
+
+	if (__intel_wait_for_register_fw(uncore,
+					 VLV_IOSF_DOORBELL_REQ, IOSF_SB_BUSY, 0,
+					 10000, 0, NULL) == 0) {
+		if (is_read)
+			*val = intel_uncore_read_fw(uncore, VLV_IOSF_DATA);
+		err = 0;
+	} else {
+		drm_dbg(&i915->drm, "IOSF sideband finish wait (%s) timed out\n",
+			is_read ? "read" : "write");
+		err = -ETIMEDOUT;
+	}
+
+	preempt_enable();
+
+	return err;
+}
+
+u32 vlv_punit_read(struct drm_i915_private *i915, u32 addr)
+{
+	u32 val = 0;
+
+	vlv_sideband_rw(i915, PCI_DEVFN(0, 0), IOSF_PORT_PUNIT,
+			SB_CRRDDA_NP, addr, &val);
+
+	return val;
+}
+
+int vlv_punit_write(struct drm_i915_private *i915, u32 addr, u32 val)
+{
+	return vlv_sideband_rw(i915, PCI_DEVFN(0, 0), IOSF_PORT_PUNIT,
+			       SB_CRWRDA_NP, addr, &val);
+}
+
+u32 vlv_bunit_read(struct drm_i915_private *i915, u32 reg)
+{
+	u32 val = 0;
+
+	vlv_sideband_rw(i915, PCI_DEVFN(0, 0), IOSF_PORT_BUNIT,
+			SB_CRRDDA_NP, reg, &val);
+
+	return val;
+}
+
+void vlv_bunit_write(struct drm_i915_private *i915, u32 reg, u32 val)
+{
+	vlv_sideband_rw(i915, PCI_DEVFN(0, 0), IOSF_PORT_BUNIT,
+			SB_CRWRDA_NP, reg, &val);
+}
+
+u32 vlv_nc_read(struct drm_i915_private *i915, u8 addr)
+{
+	u32 val = 0;
+
+	vlv_sideband_rw(i915, PCI_DEVFN(0, 0), IOSF_PORT_NC,
+			SB_CRRDDA_NP, addr, &val);
+
+	return val;
+}
+
+u32 vlv_iosf_sb_read(struct drm_i915_private *i915, u8 port, u32 reg)
+{
+	u32 val = 0;
+
+	vlv_sideband_rw(i915, PCI_DEVFN(0, 0), port,
+			SB_CRRDDA_NP, reg, &val);
+
+	return val;
+}
+
+void vlv_iosf_sb_write(struct drm_i915_private *i915,
+		       u8 port, u32 reg, u32 val)
+{
+	vlv_sideband_rw(i915, PCI_DEVFN(0, 0), port,
+			SB_CRWRDA_NP, reg, &val);
+}
+
+u32 vlv_cck_read(struct drm_i915_private *i915, u32 reg)
+{
+	u32 val = 0;
+
+	vlv_sideband_rw(i915, PCI_DEVFN(0, 0), IOSF_PORT_CCK,
+			SB_CRRDDA_NP, reg, &val);
+
+	return val;
+}
+
+void vlv_cck_write(struct drm_i915_private *i915, u32 reg, u32 val)
+{
+	vlv_sideband_rw(i915, PCI_DEVFN(0, 0), IOSF_PORT_CCK,
+			SB_CRWRDA_NP, reg, &val);
+}
+
+u32 vlv_ccu_read(struct drm_i915_private *i915, u32 reg)
+{
+	u32 val = 0;
+
+	vlv_sideband_rw(i915, PCI_DEVFN(0, 0), IOSF_PORT_CCU,
+			SB_CRRDDA_NP, reg, &val);
+
+	return val;
+}
+
+void vlv_ccu_write(struct drm_i915_private *i915, u32 reg, u32 val)
+{
+	vlv_sideband_rw(i915, PCI_DEVFN(0, 0), IOSF_PORT_CCU,
+			SB_CRWRDA_NP, reg, &val);
+}
+
+static u32 vlv_dpio_phy_iosf_port(struct drm_i915_private *i915, enum dpio_phy phy)
+{
+	/*
+	 * IOSF_PORT_DPIO: VLV x2 PHY (DP/HDMI B and C), CHV x1 PHY (DP/HDMI D)
+	 * IOSF_PORT_DPIO_2: CHV x2 PHY (DP/HDMI B and C)
+	 */
+	if (IS_CHERRYVIEW(i915))
+		return phy == DPIO_PHY0 ? IOSF_PORT_DPIO_2 : IOSF_PORT_DPIO;
+	else
+		return IOSF_PORT_DPIO;
+}
+
+u32 vlv_dpio_read(struct drm_i915_private *i915, enum pipe pipe, int reg)
+{
+	u32 port = vlv_dpio_phy_iosf_port(i915, DPIO_PHY(pipe));
+	u32 val = 0;
+
+	vlv_sideband_rw(i915, DPIO_DEVFN, port, SB_MRD_NP, reg, &val);
+
+	/*
+	 * FIXME: There might be some registers where all 1's is a valid value,
+	 * so ideally we should check the register offset instead...
+	 */
+	drm_WARN(&i915->drm, val == 0xffffffff,
+		 "DPIO read pipe %c reg 0x%x == 0x%x\n",
+		 pipe_name(pipe), reg, val);
+
+	return val;
+}
+
+void vlv_dpio_write(struct drm_i915_private *i915,
+		    enum pipe pipe, int reg, u32 val)
+{
+	u32 port = vlv_dpio_phy_iosf_port(i915, DPIO_PHY(pipe));
+
+	vlv_sideband_rw(i915, DPIO_DEVFN, port, SB_MWR_NP, reg, &val);
+}
+
+u32 vlv_flisdsi_read(struct drm_i915_private *i915, u32 reg)
+{
+	u32 val = 0;
+
+	vlv_sideband_rw(i915, DPIO_DEVFN, IOSF_PORT_FLISDSI, SB_CRRDDA_NP,
+			reg, &val);
+	return val;
+}
+
+void vlv_flisdsi_write(struct drm_i915_private *i915, u32 reg, u32 val)
+{
+	vlv_sideband_rw(i915, DPIO_DEVFN, IOSF_PORT_FLISDSI, SB_CRWRDA_NP,
+			reg, &val);
+}