[Intel-gfx] [PATCH 3/7] drm/i915/hwmon: Power PL1 limit and TDP setting

Badal Nilawar
2022-09-27T05:48:31Z

From: Dale B Stimson <dale.b.stimson@intel.com>

Use i915 HWMON to display/modify dGfx power PL1 limit and TDP setting.

v2:
- Fix review comments (Ashutosh)
- Do not restore power1_max upon module unload/load sequence
because on production systems modules are always loaded
and not unloaded/reloaded (Ashutosh)
- Fix review comments (Jani)
- Remove endianness conversion (Ashutosh)
v3: Add power1_rated_max (Ashutosh)
v4:
- Use macro HWMON_CHANNEL_INFO to define power channel (Guenter)
- Update the date and kernel version in Documentation (Badal)
v5: Use hwm_ prefix for static functions (Ashutosh)
v6: Fix review comments (Ashutosh)
v7:
- Define PCU_PACKAGE_POWER_SKU for DG1,DG2 and move
PKG_PKG_TDP to intel_mchbar_regs.h (Anshuman)
- KernelVersion: 6.2, Date: February 2023 in doc (Tvrtko)

Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Dale B Stimson <dale.b.stimson@intel.com>
Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Riana Tauro <riana.tauro@intel.com>
Signed-off-by: Badal Nilawar <badal.nilawar@intel.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
---
.../ABI/testing/sysfs-driver-intel-i915-hwmon | 20 +++
drivers/gpu/drm/i915/i915_hwmon.c | 158 +++++++++++++++++-
drivers/gpu/drm/i915/intel_mchbar_regs.h | 12 ++
3 files changed, 188 insertions(+), 2 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-driver-intel-i915-hwmon b/Documentation/ABI/testing/sysfs-driver-intel-i915-hwmon
index cd9554c1a4f8..16e697b1db3d 100644
--- a/Documentation/ABI/testing/sysfs-driver-intel-i915-hwmon
+++ b/Documentation/ABI/testing/sysfs-driver-intel-i915-hwmon
@@ -5,3 +5,23 @@ Contact: dri-devel@lists.freedesktop.org
Description: RO. Current Voltage in millivolt.

Only supported for particular Intel i915 graphics platforms.
+
+What: /sys/devices/.../hwmon/hwmon/power1_max
+Date: February 2023
+KernelVersion: 6.2
+Contact: dri-devel@lists.freedesktop.org
+Description: RW. Card reactive sustained (PL1/Tau) power limit in microwatts.
+
+ The power controller will throttle the operating frequency
+ if the power averaged over a window (typically seconds)
+ exceeds this limit.
+
+ Only supported for particular Intel i915 graphics platforms.
+
+What: /sys/devices/.../hwmon/hwmon/power1_rated_max
+Date: February 2023
+KernelVersion: 6.2
+Contact: dri-devel@lists.freedesktop.org
+Description: RO. Card default power limit (default TDP setting).
+
+ Only supported for particular Intel i915 graphics platforms.
diff --git a/drivers/gpu/drm/i915/i915_hwmon.c b/drivers/gpu/drm/i915/i915_hwmon.c
index 9fcff6a884ee..53d34a7a86f7 100644
--- a/drivers/gpu/drm/i915/i915_hwmon.c
+++ b/drivers/gpu/drm/i915/i915_hwmon.c
@@ -16,11 +16,16 @@
/*
* SF_* - scale factors for particular quantities according to hwmon spec.
* - voltage - millivolts
+ * - power - microwatts
*/
#define SF_VOLTAGE 1000
+#define SF_POWER 1000000

struct hwm_reg {
i915_reg_t gt_perf_status;
+ i915_reg_t pkg_power_sku_unit;
+ i915_reg_t pkg_power_sku;
+ i915_reg_t pkg_rapl_limit;
};

struct hwm_drvdata {
@@ -34,10 +39,68 @@ struct i915_hwmon {
struct hwm_drvdata ddat;
struct mutex hwmon_lock; /* counter overflow logic and rmw */
struct hwm_reg rg;
+ int scl_shift_power;
};

+static void
+hwm_locked_with_pm_intel_uncore_rmw(struct hwm_drvdata *ddat,
+ i915_reg_t reg, u32 clear, u32 set)
+{
+ struct i915_hwmon *hwmon = ddat->hwmon;
+ struct intel_uncore *uncore = ddat->uncore;
+ intel_wakeref_t wakeref;
+
+ mutex_lock(&hwmon->hwmon_lock);
+
+ with_intel_runtime_pm(uncore->rpm, wakeref)
+ intel_uncore_rmw(uncore, reg, clear, set);
+
+ mutex_unlock(&hwmon->hwmon_lock);
+}
+
+/*
+ * This function's return type of u64 allows for the case where the scaling
+ * of the field taken from the 32-bit register value might cause a result to
+ * exceed 32 bits.
+ */
+static u64
+hwm_field_read_and_scale(struct hwm_drvdata *ddat, i915_reg_t rgadr,
+ u32 field_msk, int nshift, u32 scale_factor)
+{
+ struct intel_uncore *uncore = ddat->uncore;
+ intel_wakeref_t wakeref;
+ u32 reg_value;
+
+ with_intel_runtime_pm(uncore->rpm, wakeref)
+ reg_value = intel_uncore_read(uncore, rgadr);
+
+ reg_value = REG_FIELD_GET(field_msk, reg_value);
+
+ return mul_u64_u32_shr(reg_value, scale_factor, nshift);
+}
+
+static void
+hwm_field_scale_and_write(struct hwm_drvdata *ddat, i915_reg_t rgadr,
+ u32 field_msk, int nshift,
+ unsigned int scale_factor, long lval)
+{
+ u32 nval;
+ u32 bits_to_clear;
+ u32 bits_to_set;
+
+ /* Computation in 64-bits to avoid overflow. Round to nearest. */
+ nval = DIV_ROUND_CLOSEST_ULL((u64)lval << nshift, scale_factor);
+
+ bits_to_clear = field_msk;
+ bits_to_set = FIELD_PREP(field_msk, nval);
+
+ hwm_locked_with_pm_intel_uncore_rmw(ddat, rgadr,
+ bits_to_clear, bits_to_set);
+}
+
static const struct hwmon_channel_info *hwm_info[] = {
HWMON_CHANNEL_INFO(in, HWMON_I_INPUT),
+ HWMON_CHANNEL_INFO(power, HWMON_P_MAX | HWMON_P_RATED_MAX),
NULL
};

@@ -71,6 +134,64 @@ hwm_in_read(struct hwm_drvdata *ddat, u32 attr, long *val)
}
}

+static umode_t
+hwm_power_is_visible(const struct hwm_drvdata *ddat, u32 attr, int chan)
+{
+ struct i915_hwmon *hwmon = ddat->hwmon;
+
+ switch (attr) {
+ case hwmon_power_max:
+ return i915_mmio_reg_valid(hwmon->rg.pkg_rapl_limit) ? 0664 : 0;
+ case hwmon_power_rated_max:
+ return i915_mmio_reg_valid(hwmon->rg.pkg_power_sku) ? 0444 : 0;
+ default:
+ return 0;
+ }
+}
+
+static int
+hwm_power_read(struct hwm_drvdata *ddat, u32 attr, int chan, long *val)
+{
+ struct i915_hwmon *hwmon = ddat->hwmon;
+
+ switch (attr) {
+ case hwmon_power_max:
+ *val = hwm_field_read_and_scale(ddat,
+ hwmon->rg.pkg_rapl_limit,
+ PKG_PWR_LIM_1,
+ hwmon->scl_shift_power,
+ SF_POWER);
+ return 0;
+ case hwmon_power_rated_max:
+ *val = hwm_field_read_and_scale(ddat,
+ hwmon->rg.pkg_power_sku,
+ PKG_PKG_TDP,
+ hwmon->scl_shift_power,
+ SF_POWER);
+ return 0;
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static int
+hwm_power_write(struct hwm_drvdata *ddat, u32 attr, int chan, long val)
+{
+ struct i915_hwmon *hwmon = ddat->hwmon;
+
+ switch (attr) {
+ case hwmon_power_max:
+ hwm_field_scale_and_write(ddat,
+ hwmon->rg.pkg_rapl_limit,
+ PKG_PWR_LIM_1,
+ hwmon->scl_shift_power,
+ SF_POWER, val);
+ return 0;
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
static umode_t
hwm_is_visible(const void *drvdata, enum hwmon_sensor_types type,
u32 attr, int channel)
@@ -80,6 +201,8 @@ hwm_is_visible(const void *drvdata, enum hwmon_sensor_types type,
switch (type) {
case hwmon_in:
return hwm_in_is_visible(ddat, attr);
+ case hwmon_power:
+ return hwm_power_is_visible(ddat, attr, channel);
default:
return 0;
}
@@ -94,6 +217,8 @@ hwm_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
switch (type) {
case hwmon_in:
return hwm_in_read(ddat, attr, val);
+ case hwmon_power:
+ return hwm_power_read(ddat, attr, channel, val);
default:
return -EOPNOTSUPP;
}
@@ -103,7 +228,11 @@ static int
hwm_write(struct device *dev, enum hwmon_sensor_types type, u32 attr,
int channel, long val)
{
+ struct hwm_drvdata *ddat = dev_get_drvdata(dev);
+
switch (type) {
+ case hwmon_power:
+ return hwm_power_write(ddat, attr, channel, val);
default:
return -EOPNOTSUPP;
}
@@ -124,11 +253,36 @@ static void
hwm_get_preregistration_info(struct drm_i915_private *i915)
{
struct i915_hwmon *hwmon = i915->hwmon;
+ struct intel_uncore *uncore = &i915->uncore;
+ intel_wakeref_t wakeref;
+ u32 val_sku_unit;

- if (IS_DG1(i915) || IS_DG2(i915))
+ if (IS_DG1(i915) || IS_DG2(i915)) {
hwmon->rg.gt_perf_status = GEN12_RPSTAT1;
- else
+ hwmon->rg.pkg_power_sku_unit = PCU_PACKAGE_POWER_SKU_UNIT;
+ hwmon->rg.pkg_power_sku = PCU_PACKAGE_POWER_SKU;
+ hwmon->rg.pkg_rapl_limit = PCU_PACKAGE_RAPL_LIMIT;
+ } else {
hwmon->rg.gt_perf_status = INVALID_MMIO_REG;
+ hwmon->rg.pkg_power_sku_unit = INVALID_MMIO_REG;
+ hwmon->rg.pkg_power_sku = INVALID_MMIO_REG;
+ hwmon->rg.pkg_rapl_limit = INVALID_MMIO_REG;
+ }
+
+ with_intel_runtime_pm(uncore->rpm, wakeref) {
+ /*
+ * The contents of register hwmon->rg.pkg_power_sku_unit do not change,
+ * so read it once and store the shift values.
+ */
+ if (i915_mmio_reg_valid(hwmon->rg.pkg_power_sku_unit)) {
+ val_sku_unit = intel_uncore_read(uncore,
+ hwmon->rg.pkg_power_sku_unit);
+ } else {
+ val_sku_unit = 0;
+ }
+
+ hwmon->scl_shift_power = REG_FIELD_GET(PKG_PWR_UNIT, val_sku_unit);
+ }
}

void i915_hwmon_register(struct drm_i915_private *i915)
diff --git a/drivers/gpu/drm/i915/intel_mchbar_regs.h b/drivers/gpu/drm/i915/intel_mchbar_regs.h
index ffc702b79579..d7e2e4711792 100644
--- a/drivers/gpu/drm/i915/intel_mchbar_regs.h
+++ b/drivers/gpu/drm/i915/intel_mchbar_regs.h
@@ -189,6 +189,16 @@
#define DG1_QCLK_RATIO_MASK REG_GENMASK(9, 2)
#define DG1_QCLK_REFERENCE REG_BIT(10)

+/*
+ * *_PACKAGE_POWER_SKU - SKU power and timing parameters.
+ */
+#define PCU_PACKAGE_POWER_SKU _MMIO(MCHBAR_MIRROR_BASE_SNB + 0x5930)
+#define PKG_PKG_TDP GENMASK_ULL(14, 0)
+
+#define PCU_PACKAGE_POWER_SKU_UNIT _MMIO(MCHBAR_MIRROR_BASE_SNB + 0x5938)
+#define PKG_PWR_UNIT REG_GENMASK(3, 0)
+#define PKG_TIME_UNIT REG_GENMASK(19, 16)
+
#define GEN6_GT_PERF_STATUS _MMIO(MCHBAR_MIRROR_BASE_SNB + 0x5948)
#define GEN6_RP_STATE_LIMITS _MMIO(MCHBAR_MIRROR_BASE_SNB + 0x5994)
#define GEN6_RP_STATE_CAP _MMIO(MCHBAR_MIRROR_BASE_SNB + 0x5998)
@@ -198,6 +208,8 @@

#define GEN10_FREQ_INFO_REC _MMIO(MCHBAR_MIRROR_BASE_SNB + 0x5ef0)
#define RPE_MASK REG_GENMASK(15, 8)
+#define PCU_PACKAGE_RAPL_LIMIT _MMIO(MCHBAR_MIRROR_BASE_SNB + 0x59a0)
+#define PKG_PWR_LIM_1 REG_GENMASK(14, 0)

/* snb MCH registers for priority tuning */
#define MCH_SSKPD _MMIO(MCHBAR_MIRROR_BASE_SNB + 0x5d10)
--
2.25.1