drm/xe/hwmon: Simplify and fix 32b wrap

Like done in commit eaa287069a70 ("drm/xe/guc_submit: Simplify and fix
diff calculation"), just use u32 for wrapping the value, which is
simpler and more correct: when wrapping on 32b, the accumulated value
was off by one.

Also, do not mix the u64 value from pmt with the u32 value used for the
calculation.

Cc: Badal Nilawar <badal.nilawar@intel.com>
Cc: Raag Jadav <raag.jadav@intel.com>
Reviewed-by: Raag Jadav <raag.jadav@intel.com>
Link: https://lore.kernel.org/r/20250530-xe-hwmon-wrap-v2-1-ce653db7fe4a@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>

diff --git a/drivers/gpu/drm/xe/xe_hwmon.c b/drivers/gpu/drm/xe/xe_hwmon.c
index 778354c91f59829bd6bbe8f849bb3ca9ace9fa65..0d32e977537cae8dd461645951d669693d7eccdb 100644 (file)
--- a/drivers/gpu/drm/xe/xe_hwmon.c
+++ b/drivers/gpu/drm/xe/xe_hwmon.c
@@ -436,7 +436,7 @@ xe_hwmon_energy_get(struct xe_hwmon *hwmon, int channel, long *energy)
 {
        struct xe_mmio *mmio = xe_root_tile_mmio(hwmon->xe);
        struct xe_hwmon_energy_info *ei = &hwmon->ei[channel];
-       u64 reg_val;
+       u32 reg_val;
        int ret = 0;
 
        /* Energy is supported only for card and pkg */
@@ -446,29 +446,27 @@ xe_hwmon_energy_get(struct xe_hwmon *hwmon, int channel, long *energy)
        }
 
        if (hwmon->xe->info.platform == XE_BATTLEMAGE) {
+               u64 pmt_val;
+
                ret = xe_pmt_telem_read(to_pci_dev(hwmon->xe->drm.dev),
                                        xe_mmio_read32(mmio, PUNIT_TELEMETRY_GUID),
-                                       &reg_val, BMG_ENERGY_STATUS_PMT_OFFSET, sizeof(reg_val));
-               if (ret != sizeof(reg_val)) {
+                                       &pmt_val, BMG_ENERGY_STATUS_PMT_OFFSET, sizeof(pmt_val));
+               if (ret != sizeof(pmt_val)) {
                        drm_warn(&hwmon->xe->drm, "energy read from pmt failed, ret %d\n", ret);
                        *energy = 0;
                        return;
                }
 
                if (channel == CHANNEL_PKG)
-                       reg_val = REG_FIELD_GET64(ENERGY_PKG, reg_val);
+                       reg_val = REG_FIELD_GET64(ENERGY_PKG, pmt_val);
                else
-                       reg_val = REG_FIELD_GET64(ENERGY_CARD, reg_val);
+                       reg_val = REG_FIELD_GET64(ENERGY_CARD, pmt_val);
        } else {
                reg_val = xe_mmio_read32(mmio, xe_hwmon_get_reg(hwmon, REG_PKG_ENERGY_STATUS,
                                                                channel));
        }
 
-       if (reg_val >= ei->reg_val_prev)
-               ei->accum_energy += reg_val - ei->reg_val_prev;
-       else
-               ei->accum_energy += UINT_MAX - ei->reg_val_prev + reg_val;
-
+       ei->accum_energy += reg_val - ei->reg_val_prev;
        ei->reg_val_prev = reg_val;
 
        *energy = mul_u64_u32_shr(ei->accum_energy, SF_ENERGY,