[PATCH v6 05/12] drm/xe/vrsr: Initialize VRSR feature

[Badal Nilawar <badal.nilawar@intel.com>]

Add the API xe_pm_vrsr_enable to initialize the VRSR feature,
requesting AUX power limit and PERST# assertion delay.

V2: Add retry mechanism while requesting AUX power limit
V3: Split xe_pm_vrsr_enable() into separate enable and
    disable functions

Signed-off-by: Badal Nilawar <badal.nilawar@intel.com>
Signed-off-by: Anshuman Gupta <anshuman.gupta@intel.com>
---
 drivers/gpu/drm/xe/xe_device_types.h |   1 +
 drivers/gpu/drm/xe/xe_pcode_api.h    |   7 ++
 drivers/gpu/drm/xe/xe_pm.c           | 110 ++++++++++++++++++++++++++-
 drivers/gpu/drm/xe/xe_pm.h           |   2 +
 4 files changed, 119 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/xe/xe_device_types.h b/drivers/gpu/drm/xe/xe_device_types.h
index 17a577772794..3b42400f8563 100644
--- a/drivers/gpu/drm/xe/xe_device_types.h
+++ b/drivers/gpu/drm/xe/xe_device_types.h
@@ -7,6 +7,7 @@
 #define _XE_DEVICE_TYPES_H_
 
 #include <linux/pci.h>
+#include <linux/pci-acpi.h>
 
 #include <drm/drm_device.h>
 #include <drm/drm_file.h>
diff --git a/drivers/gpu/drm/xe/xe_pcode_api.h b/drivers/gpu/drm/xe/xe_pcode_api.h
index 85cc7478b787..15687bb57c94 100644
--- a/drivers/gpu/drm/xe/xe_pcode_api.h
+++ b/drivers/gpu/drm/xe/xe_pcode_api.h
@@ -72,6 +72,13 @@
 #define       FAN_TABLE				1
 #define       VR_CONFIG				2
 
+#define	  PCODE_D3_VRAM_SELF_REFRESH	0x71
+#define	    PCODE_D3_VRSR_SC_DISABLE	0x0
+#define	    PCODE_D3_VRSR_SC_ENABLE	0x1
+#define     PCODE_D3_VRSR_SC_AUX_PL_AND_PERST_DELAY	0x2
+#define	    POWER_D3_VRSR_PERST_MASK	REG_GENMASK(31, 16)
+#define	    POWER_D3_VRSR_AUX_PL_MASK	REG_GENMASK(15, 0)
+
 #define   PCODE_FREQUENCY_CONFIG		0x6e
 /* Frequency Config Sub Commands (param1) */
 #define     PCODE_MBOX_FC_SC_READ_FUSED_P0	0x0
diff --git a/drivers/gpu/drm/xe/xe_pm.c b/drivers/gpu/drm/xe/xe_pm.c
index 18a44b395559..3fe673f0f87d 100644
--- a/drivers/gpu/drm/xe/xe_pm.c
+++ b/drivers/gpu/drm/xe/xe_pm.c
@@ -5,6 +5,7 @@
 
 #include "xe_pm.h"
 
+#include <linux/delay.h>
 #include <linux/fault-inject.h>
 #include <linux/pm_runtime.h>
 #include <linux/suspend.h>
@@ -25,6 +26,7 @@
 #include "xe_irq.h"
 #include "xe_late_bind_fw.h"
 #include "xe_mmio.h"
+#include "xe_pcode_api.h"
 #include "xe_pcode.h"
 #include "xe_pxp.h"
 #include "xe_sriov_vf_ccs.h"
@@ -343,6 +345,112 @@ static bool xe_pm_vrsr_capable(struct xe_device *xe)
 	return val & VRAM_SR_SUPPORTED;
 }
 
+static int pci_acpi_aux_power_setup(struct xe_device *xe)
+{
+	struct xe_tile *root_tile = xe_device_get_root_tile(xe);
+	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
+	int ret;
+	u32 uval;
+	u32 aux_pwr_limit;
+	u32 retry_interval;
+	u32 perst_delay;
+
+	ret = xe_pcode_read(root_tile, PCODE_MBOX(PCODE_D3_VRAM_SELF_REFRESH,
+						  PCODE_D3_VRSR_SC_AUX_PL_AND_PERST_DELAY, 0),
+			    &uval, NULL);
+	if (ret)
+		return ret;
+
+	aux_pwr_limit = REG_FIELD_GET(POWER_D3_VRSR_AUX_PL_MASK, uval);
+	perst_delay = REG_FIELD_GET(POWER_D3_VRSR_PERST_MASK, uval);
+
+	drm_dbg(&xe->drm, "Aux Power limit = %d mW\n", aux_pwr_limit);
+	drm_dbg(&xe->drm, "PERST# Assertion delay = %d microseconds\n", perst_delay);
+
+retry:
+	ret = pci_acpi_request_d3cold_aux_power(pdev, aux_pwr_limit, &retry_interval);
+
+	if (ret == -EAGAIN) {
+		drm_warn(&xe->drm, "D3cold Aux Power request needs retry interval: %d seconds\n",
+			 retry_interval);
+		msleep(retry_interval * 1000);
+		goto retry;
+	}
+
+	if (ret)
+		return ret;
+
+	ret = pci_acpi_add_perst_assertion_delay(pdev, perst_delay);
+
+	return ret;
+}
+
+static void xe_pm_vrsr_init(struct xe_device *xe)
+{
+	int ret;
+
+	if (!xe->info.has_vrsr)
+		return;
+
+	if (!xe_pm_vrsr_capable(xe))
+		return;
+
+	/*
+	 * If the VRSR initialization fails, the device will proceed with the regular
+	 * D3cold flow
+	 */
+	ret = pci_acpi_aux_power_setup(xe);
+	if (ret) {
+		drm_info(&xe->drm, "VRSR capable: No\n");
+		return;
+	}
+
+	xe->d3cold.vrsr_capable = true;
+	drm_info(&xe->drm, "VRSR capable: Yes\n");
+}
+
+/**
+ * xe_pm_vrsr_enable - Enable VRAM self refresh
+ * @xe: The xe device.
+ *
+ * Enable VRSR feature in D3cold path.
+ *
+ * Return: It returns 0 on success and errno on failure.
+ */
+int xe_pm_vrsr_enable(struct xe_device *xe)
+{
+	struct xe_tile *root_tile = xe_device_get_root_tile(xe);
+	int ret;
+
+	if (!xe->d3cold.vrsr_capable)
+		return -ENXIO;
+
+	drm_dbg(&xe->drm, "Enabling VRSR\n");
+
+	ret = xe_pcode_write(root_tile, PCODE_MBOX(PCODE_D3_VRAM_SELF_REFRESH,
+						   PCODE_D3_VRSR_SC_ENABLE, 0), 0);
+	return ret;
+}
+
+/**
+ * xe_pm_vrsr_disable - Disable VRAM self refresh
+ * @xe: The xe device.
+ *
+ * Disable VRSR feature in D3cold path.
+ */
+void xe_pm_vrsr_disable(struct xe_device *xe)
+{
+	struct xe_tile *root_tile = xe_device_get_root_tile(xe);
+
+	if (!xe->d3cold.vrsr_capable)
+		return;
+
+	drm_dbg(&xe->drm, "Disabling VRSR\n");
+
+	xe_pcode_write(root_tile, PCODE_MBOX(PCODE_D3_VRAM_SELF_REFRESH,
+					     PCODE_D3_VRSR_SC_DISABLE, 0), 0);
+}
+
 static void xe_pm_runtime_init(struct xe_device *xe)
 {
 	struct device *dev = xe->drm.dev;
@@ -487,7 +595,7 @@ int xe_pm_init(struct xe_device *xe)
 		err = xe_pm_set_vram_threshold(xe, vram_threshold);
 		if (err)
 			goto err_unregister;
-		xe->d3cold.vrsr_capable = xe_pm_vrsr_capable(xe);
+		xe_pm_vrsr_init(xe);
 	}
 
 	xe_pm_runtime_init(xe);
diff --git a/drivers/gpu/drm/xe/xe_pm.h b/drivers/gpu/drm/xe/xe_pm.h
index 6b27039e7b2d..8c7fe8e4241d 100644
--- a/drivers/gpu/drm/xe/xe_pm.h
+++ b/drivers/gpu/drm/xe/xe_pm.h
@@ -54,4 +54,6 @@ DEFINE_GUARD_COND(xe_pm_runtime, _ioctl, xe_pm_runtime_get_ioctl(_T), _RET >= 0)
 DEFINE_GUARD(xe_pm_runtime_release_only, struct xe_device *,
 	     __xe_pm_runtime_noop(_T), xe_pm_runtime_put(_T));
 
+int xe_pm_vrsr_enable(struct xe_device *xe);
+void xe_pm_vrsr_disable(struct xe_device *xe);
 #endif
-- 
2.52.0