HW allows arbitrary PL1 limits to be set but silently clamps these values
to "typical but not guaranteed" min/max values in pkg_power_sku
register. Follow the same pattern for sysfs, allow arbitrary PL1 limits to
be set but display clamped values when read.
Signed-off-by: Ashutosh Dixit <ashutosh.dixit@xxxxxxxxx>
---
drivers/gpu/drm/i915/i915_hwmon.c | 39 ++++++++++++++++++++----
drivers/gpu/drm/i915/intel_mchbar_regs.h | 2 ++
2 files changed, 35 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_hwmon.c b/drivers/gpu/drm/i915/i915_hwmon.c
index cca7a4350ec8f..1225bc432f0d5 100644
--- a/drivers/gpu/drm/i915/i915_hwmon.c
+++ b/drivers/gpu/drm/i915/i915_hwmon.c
@@ -359,6 +359,38 @@ hwm_power_is_visible(const struct hwm_drvdata *ddat, u32 attr, int chan)
}
}
+/*
+ * HW allows arbitrary PL1 limits to be set but silently clamps these values to
+ * "typical but not guaranteed" min/max values in rg.pkg_power_sku. Follow the
+ * same pattern for sysfs, allow arbitrary PL1 limits to be set but display
+ * clamped values when read. Write/read I1 also follows the same pattern.
+ */
+static int
+hwm_power_max_read(struct hwm_drvdata *ddat, long *val)
+{
+ struct i915_hwmon *hwmon = ddat->hwmon;
+ intel_wakeref_t wakeref;
+ u64 r, min, max;
+
+ *val = hwm_field_read_and_scale(ddat,
+ hwmon->rg.pkg_rapl_limit,
+ PKG_PWR_LIM_1,
+ hwmon->scl_shift_power,
+ SF_POWER);
+
+ with_intel_runtime_pm(ddat->uncore->rpm, wakeref)
+ r = intel_uncore_read64(ddat->uncore, hwmon->rg.pkg_power_sku);
+ min = REG_FIELD_GET(PKG_MIN_PWR, r);
+ min = mul_u64_u32_shr(min, SF_POWER, hwmon->scl_shift_power);
+ max = REG_FIELD_GET(PKG_MAX_PWR, r);
+ max = mul_u64_u32_shr(max, SF_POWER, hwmon->scl_shift_power);
+
+ if (min && max)
+ *val = clamp_t(u64, *val, min, max);
+
+ return 0;
+}
+
static int
hwm_power_read(struct hwm_drvdata *ddat, u32 attr, int chan, long *val)
{
@@ -368,12 +400,7 @@ hwm_power_read(struct hwm_drvdata *ddat, u32 attr, int chan, long *val)
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;
+ return hwm_power_max_read(ddat, val);
case hwmon_power_rated_max:
*val = hwm_field_read_and_scale(ddat,
hwmon->rg.pkg_power_sku,
diff --git a/drivers/gpu/drm/i915/intel_mchbar_regs.h b/drivers/gpu/drm/i915/intel_mchbar_regs.h
index f93e9af43ac35..73900c098d591 100644
--- a/drivers/gpu/drm/i915/intel_mchbar_regs.h
+++ b/drivers/gpu/drm/i915/intel_mchbar_regs.h
@@ -194,6 +194,8 @@
*/
#define PCU_PACKAGE_POWER_SKU _MMIO(MCHBAR_MIRROR_BASE_SNB + 0x5930)
#define PKG_PKG_TDP GENMASK_ULL(14, 0)
+#define PKG_MIN_PWR GENMASK_ULL(30, 16)
+#define PKG_MAX_PWR GENMASK_ULL(46, 32)
#define PKG_MAX_WIN GENMASK_ULL(54, 48)
#define PKG_MAX_WIN_X GENMASK_ULL(54, 53)
#define PKG_MAX_WIN_Y GENMASK_ULL(52, 48)
--
2.38.0
