drm/xe/hwmon: Expose card reactive critical power

Expose the card reactive critical (I1) power. I1 is exposed as
power1_crit in microwatts (typically for client products) or as
curr1_crit in milliamperes (typically for server).

v2: Move PCODE_MBOX macro to pcode file (Riana)
v3: s/IS_DG2/(gt_to_xe(gt)->info.platform == XE_DG2)
v4: Fix review comments (Andi)

Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Riana Tauro <riana.tauro@intel.com>
Signed-off-by: Badal Nilawar <badal.nilawar@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://lore.kernel.org/r/20230925081842.3566834-3-badal.nilawar@intel.com
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

Documentation/ABI/testing/sysfs-driver-intel-xe-hwmon

@@ -20,3 +20,29 @@ Description:	RO. Card default power limit (default TDP setting).
 
 		Only supported for particular Intel xe graphics platforms.
 
+What:		/sys/devices/.../hwmon/hwmon<i>/power1_crit
+Date:		September 2023
+KernelVersion:	6.5
+Contact:	intel-xe@lists.freedesktop.org
+Description:	RW. Card reactive critical (I1) power limit in microwatts.
+
+		Card reactive critical (I1) power limit in microwatts is exposed
+		for client products. The power controller will throttle the
+		operating frequency if the power averaged over a window exceeds
+		this limit.
+
+		Only supported for particular Intel xe graphics platforms.
+
+What:		/sys/devices/.../hwmon/hwmon<i>/curr1_crit
+Date:		September 2023
+KernelVersion:	6.5
+Contact:	intel-xe@lists.freedesktop.org
+Description:	RW. Card reactive critical (I1) power limit in milliamperes.
+
+		Card reactive critical (I1) power limit in milliamperes is
+		exposed for server products. The power controller will throttle
+		the operating frequency if the power averaged over a window
+		exceeds this limit.
+
+		Only supported for particular Intel xe graphics platforms.
+

drivers/gpu/drm/xe/xe_hwmon.c

@@ -12,6 +12,8 @@
 #include "xe_gt.h"
 #include "xe_hwmon.h"
 #include "xe_mmio.h"
+#include "xe_pcode.h"
+#include "xe_pcode_api.h"
 
 enum xe_hwmon_reg {
 	REG_PKG_RAPL_LIMIT,
@@ -29,6 +31,7 @@ enum xe_hwmon_reg_operation {
  * SF_* - scale factors for particular quantities according to hwmon spec.
  */
 #define SF_POWER	1000000		/* microwatts */
+#define SF_CURR		1000		/* milliamperes */
 
 struct xe_hwmon {
 	struct device *hwmon_dev;
@@ -184,18 +187,43 @@ static int xe_hwmon_power_rated_max_read(struct xe_hwmon *hwmon, long *value)
 }
 
 static const struct hwmon_channel_info *hwmon_info[] = {
-	HWMON_CHANNEL_INFO(power, HWMON_P_MAX | HWMON_P_RATED_MAX),
+	HWMON_CHANNEL_INFO(power, HWMON_P_MAX | HWMON_P_RATED_MAX | HWMON_P_CRIT),
+	HWMON_CHANNEL_INFO(curr, HWMON_C_CRIT),
 	NULL
 };
 
+/* I1 is exposed as power_crit or as curr_crit depending on bit 31 */
+static int xe_hwmon_pcode_read_i1(struct xe_gt *gt, u32 *uval)
+{
+	/* Avoid Illegal Subcommand error */
+	if (gt_to_xe(gt)->info.platform == XE_DG2)
+		return -ENXIO;
+
+	return xe_pcode_read(gt, PCODE_MBOX(PCODE_POWER_SETUP,
+			     POWER_SETUP_SUBCOMMAND_READ_I1, 0),
+			     uval, 0);
+}
+
+static int xe_hwmon_pcode_write_i1(struct xe_gt *gt, u32 uval)
+{
+	return xe_pcode_write(gt, PCODE_MBOX(PCODE_POWER_SETUP,
+			      POWER_SETUP_SUBCOMMAND_WRITE_I1, 0),
+			      uval);
+}
+
 static umode_t
 xe_hwmon_power_is_visible(struct xe_hwmon *hwmon, u32 attr, int chan)
 {
+	u32 uval;
+
 	switch (attr) {
 	case hwmon_power_max:
 		return xe_hwmon_get_reg(hwmon, REG_PKG_RAPL_LIMIT) ? 0664 : 0;
 	case hwmon_power_rated_max:
 		return xe_hwmon_get_reg(hwmon, REG_PKG_POWER_SKU) ? 0444 : 0;
+	case hwmon_power_crit:
+		return (xe_hwmon_pcode_read_i1(hwmon->gt, &uval) ||
+			!(uval & POWER_SETUP_I1_WATTS)) ? 0 : 0644;
 	default:
 		return 0;
 	}
@@ -204,11 +232,23 @@ xe_hwmon_power_is_visible(struct xe_hwmon *hwmon, u32 attr, int chan)
 static int
 xe_hwmon_power_read(struct xe_hwmon *hwmon, u32 attr, int chan, long *val)
 {
+	int ret;
+	u32 uval;
+
 	switch (attr) {
 	case hwmon_power_max:
 		return xe_hwmon_power_max_read(hwmon, val);
 	case hwmon_power_rated_max:
 		return xe_hwmon_power_rated_max_read(hwmon, val);
+	case hwmon_power_crit:
+		ret = xe_hwmon_pcode_read_i1(hwmon->gt, &uval);
+		if (ret)
+			return ret;
+		if (!(uval & POWER_SETUP_I1_WATTS))
+			return -ENODEV;
+		*val = mul_u64_u32_shr(REG_FIELD_GET(POWER_SETUP_I1_DATA_MASK, uval),
+				       SF_POWER, POWER_SETUP_I1_SHIFT);
+		return 0;
 	default:
 		return -EOPNOTSUPP;
 	}
@@ -217,9 +257,63 @@ xe_hwmon_power_read(struct xe_hwmon *hwmon, u32 attr, int chan, long *val)
 static int
 xe_hwmon_power_write(struct xe_hwmon *hwmon, u32 attr, int chan, long val)
 {
+	u32 uval;
+
 	switch (attr) {
 	case hwmon_power_max:
 		return xe_hwmon_power_max_write(hwmon, val);
+	case hwmon_power_crit:
+		uval = DIV_ROUND_CLOSEST_ULL(val << POWER_SETUP_I1_SHIFT, SF_POWER);
+		return xe_hwmon_pcode_write_i1(hwmon->gt, uval);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static umode_t
+xe_hwmon_curr_is_visible(const struct xe_hwmon *hwmon, u32 attr)
+{
+	u32 uval;
+
+	switch (attr) {
+	case hwmon_curr_crit:
+		return (xe_hwmon_pcode_read_i1(hwmon->gt, &uval) ||
+			(uval & POWER_SETUP_I1_WATTS)) ? 0 : 0644;
+	default:
+		return 0;
+	}
+}
+
+static int
+xe_hwmon_curr_read(struct xe_hwmon *hwmon, u32 attr, long *val)
+{
+	int ret;
+	u32 uval;
+
+	switch (attr) {
+	case hwmon_curr_crit:
+		ret = xe_hwmon_pcode_read_i1(hwmon->gt, &uval);
+		if (ret)
+			return ret;
+		if (uval & POWER_SETUP_I1_WATTS)
+			return -ENODEV;
+		*val = mul_u64_u32_shr(REG_FIELD_GET(POWER_SETUP_I1_DATA_MASK, uval),
+				       SF_CURR, POWER_SETUP_I1_SHIFT);
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int
+xe_hwmon_curr_write(struct xe_hwmon *hwmon, u32 attr, long val)
+{
+	u32 uval;
+
+	switch (attr) {
+	case hwmon_curr_crit:
+		uval = DIV_ROUND_CLOSEST_ULL(val << POWER_SETUP_I1_SHIFT, SF_CURR);
+		return xe_hwmon_pcode_write_i1(hwmon->gt, uval);
 	default:
 		return -EOPNOTSUPP;
 	}
@@ -238,6 +332,9 @@ xe_hwmon_is_visible(const void *drvdata, enum hwmon_sensor_types type,
 	case hwmon_power:
 		ret = xe_hwmon_power_is_visible(hwmon, attr, channel);
 		break;
+	case hwmon_curr:
+		ret = xe_hwmon_curr_is_visible(hwmon, attr);
+		break;
 	default:
 		ret = 0;
 		break;
@@ -261,6 +358,9 @@ xe_hwmon_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
 	case hwmon_power:
 		ret = xe_hwmon_power_read(hwmon, attr, channel, val);
 		break;
+	case hwmon_curr:
+		ret = xe_hwmon_curr_read(hwmon, attr, val);
+		break;
 	default:
 		ret = -EOPNOTSUPP;
 		break;
@@ -284,6 +384,9 @@ xe_hwmon_write(struct device *dev, enum hwmon_sensor_types type, u32 attr,
 	case hwmon_power:
 		ret = xe_hwmon_power_write(hwmon, attr, channel, val);
 		break;
+	case hwmon_curr:
+		ret = xe_hwmon_curr_write(hwmon, attr, val);
+		break;
 	default:
 		ret = -EOPNOTSUPP;
 		break;

drivers/gpu/drm/xe/xe_pcode.h

@@ -22,4 +22,9 @@ int xe_pcode_write_timeout(struct xe_gt *gt, u32 mbox, u32 val,
 int xe_pcode_request(struct xe_gt *gt, u32 mbox, u32 request,
 		     u32 reply_mask, u32 reply, int timeout_ms);
 
+#define PCODE_MBOX(mbcmd, param1, param2)\
+	(FIELD_PREP(PCODE_MB_COMMAND, mbcmd)\
+	| FIELD_PREP(PCODE_MB_PARAM1, param1)\
+	| FIELD_PREP(PCODE_MB_PARAM2, param2))
+
 #endif

drivers/gpu/drm/xe/xe_pcode_api.h

@@ -35,6 +35,13 @@
 #define     DGFX_GET_INIT_STATUS	0x0
 #define     DGFX_INIT_STATUS_COMPLETE	0x1
 
+#define   PCODE_POWER_SETUP			0x7C
+#define     POWER_SETUP_SUBCOMMAND_READ_I1	0x4
+#define     POWER_SETUP_SUBCOMMAND_WRITE_I1	0x5
+#define	    POWER_SETUP_I1_WATTS		REG_BIT(31)
+#define	    POWER_SETUP_I1_SHIFT		6	/* 10.6 fixed point format */
+#define	    POWER_SETUP_I1_DATA_MASK		REG_GENMASK(15, 0)
+
 struct pcode_err_decode {
 	int errno;
 	const char *str;