Commit 923860a8 authored by Kuppuswamy Sathyanarayanan's avatar Kuppuswamy Sathyanarayanan Committed by Rafael J. Wysocki
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powercap: intel_rapl: Use shifts for power-of-2 operations 



Replace division by (1 << value) with shift operations for clarity and
consistency. Add ULL suffix to avoid undefined behavior from shifting
signed integers.

No functional changes intended.

Signed-off-by: default avatarKuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Acked-by: default avatarSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Link: https://patch.msgid.link/20260212233044.329790-6-sathyanarayanan.kuppuswamy@linux.intel.com


Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 637bf740

drivers/powercap/intel_rapl_common.c

+10 −10
Original line number Diff line number Diff line
@@ -964,13 +964,13 @@ static int rapl_check_unit_core(struct rapl_domain *rd) 
	}



	value = (ra.value & ENERGY_UNIT_MASK) >> ENERGY_UNIT_OFFSET;

	rd->energy_unit = ENERGY_UNIT_SCALE * 1000000 / (1 << value);

	rd->energy_unit = (ENERGY_UNIT_SCALE * 1000000) >> value;



	value = (ra.value & POWER_UNIT_MASK) >> POWER_UNIT_OFFSET;

	rd->power_unit = 1000000 / (1 << value);

	rd->power_unit = 1000000 >> value;



	value = (ra.value & TIME_UNIT_MASK) >> TIME_UNIT_OFFSET;

	rd->time_unit = 1000000 / (1 << value);

	rd->time_unit = 1000000 >> value;



	pr_debug("Core CPU %s:%s energy=%dpJ, time=%dus, power=%duW\n",

		 rd->rp->name, rd->name, rd->energy_unit, rd->time_unit, rd->power_unit);
@@ -992,13 +992,13 @@ static int rapl_check_unit_atom(struct rapl_domain *rd) 
	}



	value = (ra.value & ENERGY_UNIT_MASK) >> ENERGY_UNIT_OFFSET;

	rd->energy_unit = ENERGY_UNIT_SCALE * 1 << value;

	rd->energy_unit = ENERGY_UNIT_SCALE * (1ULL << value);



	value = (ra.value & POWER_UNIT_MASK) >> POWER_UNIT_OFFSET;

	rd->power_unit = (1 << value) * 1000;

	rd->power_unit = (1ULL << value) * 1000;



	value = (ra.value & TIME_UNIT_MASK) >> TIME_UNIT_OFFSET;

	rd->time_unit = 1000000 / (1 << value);

	rd->time_unit = 1000000 >> value;



	pr_debug("Atom %s:%s energy=%dpJ, time=%dus, power=%duW\n",

		 rd->rp->name, rd->name, rd->energy_unit, rd->time_unit, rd->power_unit);
@@ -1121,7 +1121,7 @@ static u64 rapl_compute_time_window_core(struct rapl_domain *rd, u64 value, 
	if (!to_raw) {

		f = (value & 0x60) >> 5;

		y = value & 0x1f;

		value = (1 << y) * (4 + f) * rd->time_unit / 4;

		value = (1ULL << y) * (4 + f) * rd->time_unit / 4;

	} else {

		if (value < rd->time_unit)

			return 0;
@@ -1169,13 +1169,13 @@ static int rapl_check_unit_tpmi(struct rapl_domain *rd) 
	}



	value = (ra.value & TPMI_ENERGY_UNIT_MASK) >> TPMI_ENERGY_UNIT_OFFSET;

	rd->energy_unit = ENERGY_UNIT_SCALE * 1000000 / (1 << value);

	rd->energy_unit = (ENERGY_UNIT_SCALE * 1000000) >> value;



	value = (ra.value & TPMI_POWER_UNIT_MASK) >> TPMI_POWER_UNIT_OFFSET;

	rd->power_unit = 1000000 / (1 << value);

	rd->power_unit = 1000000 >> value;



	value = (ra.value & TPMI_TIME_UNIT_MASK) >> TPMI_TIME_UNIT_OFFSET;

	rd->time_unit = 1000000 / (1 << value);

	rd->time_unit = 1000000 >> value;



	pr_debug("Core CPU %s:%s energy=%dpJ, time=%dus, power=%duW\n",

		 rd->rp->name, rd->name, rd->energy_unit, rd->time_unit, rd->power_unit);