[PATCH 09/15] powercap/intel_rapl: Cleanup Power Limits support

From: Zhang Rui
Date: Thu Mar 16 2023 - 11:43:12 EST


The same set of operations are shared by different Powert Limits,
including Power Limit get/set, Power Limit enable/disable, clamping
enable/disable, time window get/set, and max power get/set, etc.

But the same operation for different Power Limit has different
primitives because they use different registers/register bits.

A lot of dirty/duplicate code was introduced to handle this difference.

Introduce a universal way to issue Power Limit operations.
Instead of using hardcoded primitive name directly, use Power Limit id
+ operation type, and hide all the Power Limit difference details in a
central place, get_pl_prim(). Two helpers, rapl_read_pl_data() and
rapl_write_pl_data(), are introduced at the same time to simply the
code for issuing Power Limit operations.

Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx>
---
drivers/powercap/intel_rapl_common.c | 343 ++++++++++++---------------
include/linux/intel_rapl.h | 1 -
2 files changed, 146 insertions(+), 198 deletions(-)

diff --git a/drivers/powercap/intel_rapl_common.c b/drivers/powercap/intel_rapl_common.c
index 0935a10b093e..3e9141dedc1d 100644
--- a/drivers/powercap/intel_rapl_common.c
+++ b/drivers/powercap/intel_rapl_common.c
@@ -96,9 +96,67 @@ enum unit_type {
#define DOMAIN_STATE_POWER_LIMIT_SET BIT(1)
#define DOMAIN_STATE_BIOS_LOCKED BIT(2)

-static const char pl1_name[] = "long_term";
-static const char pl2_name[] = "short_term";
-static const char pl4_name[] = "peak_power";
+static const char *pl_names[NR_POWER_LIMITS] = {
+ [POWER_LIMIT1] = "long_term",
+ [POWER_LIMIT2] = "short_term",
+ [POWER_LIMIT4] = "peak_power",
+};
+
+enum pl_prims {
+ PL_ENABLE,
+ PL_CLAMP,
+ PL_LIMIT,
+ PL_TIME_WINDOW,
+ PL_MAX_POWER,
+};
+
+static bool is_pl_valid(struct rapl_domain *rd, int pl)
+{
+ if (pl < POWER_LIMIT1 || pl > POWER_LIMIT4)
+ return false;
+ return rd->rpl[pl].name ? true : false;
+}
+
+static int get_pl_prim(int pl, enum pl_prims prim)
+{
+ switch (pl) {
+ case POWER_LIMIT1:
+ if (prim == PL_ENABLE)
+ return PL1_ENABLE;
+ if (prim == PL_CLAMP)
+ return PL1_CLAMP;
+ if (prim == PL_LIMIT)
+ return POWER_LIMIT1;
+ if (prim == PL_TIME_WINDOW)
+ return TIME_WINDOW1;
+ if (prim == PL_MAX_POWER)
+ return THERMAL_SPEC_POWER;
+ return -EINVAL;
+ case POWER_LIMIT2:
+ if (prim == PL_ENABLE)
+ return PL2_ENABLE;
+ if (prim == PL_CLAMP)
+ return PL2_CLAMP;
+ if (prim == PL_LIMIT)
+ return POWER_LIMIT2;
+ if (prim == PL_TIME_WINDOW)
+ return TIME_WINDOW2;
+ if (prim == PL_MAX_POWER)
+ return MAX_POWER;
+ return -EINVAL;
+ case POWER_LIMIT4:
+ if (prim == PL_LIMIT)
+ return POWER_LIMIT4;
+ if (prim == PL_ENABLE)
+ return PL4_ENABLE;
+ /* PL4 would be around two times PL2, use same prim as PL2. */
+ if (prim == PL_MAX_POWER)
+ return MAX_POWER;
+ return -EINVAL;
+ default:
+ return -EINVAL;
+ }
+}

#define power_zone_to_rapl_domain(_zone) \
container_of(_zone, struct rapl_domain, power_zone)
@@ -155,6 +213,12 @@ static int rapl_read_data_raw(struct rapl_domain *rd,
static int rapl_write_data_raw(struct rapl_domain *rd,
enum rapl_primitives prim,
unsigned long long value);
+static int rapl_read_pl_data(struct rapl_domain *rd, int pl,
+ enum pl_prims pl_prim,
+ bool xlate, u64 *data);
+static int rapl_write_pl_data(struct rapl_domain *rd, int pl,
+ enum pl_prims pl_prim,
+ unsigned long long value);
static u64 rapl_unit_xlate(struct rapl_domain *rd,
enum unit_type type, u64 value, int to_raw);
static void package_power_limit_irq_save(struct rapl_package *rp);
@@ -222,7 +286,7 @@ static int find_nr_power_limit(struct rapl_domain *rd)
int i, nr_pl = 0;

for (i = 0; i < NR_POWER_LIMITS; i++) {
- if (rd->rpl[i].name)
+ if (is_pl_valid(rd, i))
nr_pl++;
}

@@ -233,37 +297,34 @@ static int set_domain_enable(struct powercap_zone *power_zone, bool mode)
{
struct rapl_domain *rd = power_zone_to_rapl_domain(power_zone);
struct rapl_defaults *rpd = get_rpd(rd->rp);
-
- if (rd->state & DOMAIN_STATE_BIOS_LOCKED)
- return -EACCES;
+ int ret;

cpus_read_lock();
- rapl_write_data_raw(rd, PL1_ENABLE, mode);
- if (rpd->set_floor_freq)
+ ret = rapl_write_pl_data(rd, POWER_LIMIT1, PL_ENABLE, mode);
+ if (!ret && rpd->set_floor_freq)
rpd->set_floor_freq(rd, mode);
cpus_read_unlock();

- return 0;
+ return ret;
}

static int get_domain_enable(struct powercap_zone *power_zone, bool *mode)
{
struct rapl_domain *rd = power_zone_to_rapl_domain(power_zone);
u64 val;
+ int ret;

if (rd->state & DOMAIN_STATE_BIOS_LOCKED) {
*mode = false;
return 0;
}
cpus_read_lock();
- if (rapl_read_data_raw(rd, PL1_ENABLE, true, &val)) {
- cpus_read_unlock();
- return -EIO;
- }
- *mode = val;
+ ret = rapl_read_pl_data(rd, POWER_LIMIT1, PL_ENABLE, true, &val);
+ if (!ret)
+ *mode = val;
cpus_read_unlock();

- return 0;
+ return ret;
}

/* per RAPL domain ops, in the order of rapl_domain_type */
@@ -319,8 +380,8 @@ static int contraint_to_pl(struct rapl_domain *rd, int cid)
{
int i, j;

- for (i = 0, j = 0; i < NR_POWER_LIMITS; i++) {
- if ((rd->rpl[i].name) && j++ == cid) {
+ for (i = POWER_LIMIT1, j = 0; i < NR_POWER_LIMITS; i++) {
+ if (is_pl_valid(rd, i) && j++ == cid) {
pr_debug("%s: index %d\n", __func__, i);
return i;
}
@@ -341,36 +402,11 @@ static int set_power_limit(struct powercap_zone *power_zone, int cid,
cpus_read_lock();
rd = power_zone_to_rapl_domain(power_zone);
id = contraint_to_pl(rd, cid);
- if (id < 0) {
- ret = id;
- goto set_exit;
- }
-
rp = rd->rp;

- if (rd->state & DOMAIN_STATE_BIOS_LOCKED) {
- dev_warn(&power_zone->dev,
- "%s locked by BIOS, monitoring only\n", rd->name);
- ret = -EACCES;
- goto set_exit;
- }
-
- switch (rd->rpl[id].prim_id) {
- case PL1_ENABLE:
- rapl_write_data_raw(rd, POWER_LIMIT1, power_limit);
- break;
- case PL2_ENABLE:
- rapl_write_data_raw(rd, POWER_LIMIT2, power_limit);
- break;
- case PL4_ENABLE:
- rapl_write_data_raw(rd, POWER_LIMIT4, power_limit);
- break;
- default:
- ret = -EINVAL;
- }
+ ret = rapl_write_pl_data(rd, id, PL_LIMIT, power_limit);
if (!ret)
package_power_limit_irq_save(rp);
-set_exit:
cpus_read_unlock();
return ret;
}
@@ -380,38 +416,17 @@ static int get_current_power_limit(struct powercap_zone *power_zone, int cid,
{
struct rapl_domain *rd;
u64 val;
- int prim;
int ret = 0;
int id;

cpus_read_lock();
rd = power_zone_to_rapl_domain(power_zone);
id = contraint_to_pl(rd, cid);
- if (id < 0) {
- ret = id;
- goto get_exit;
- }

- switch (rd->rpl[id].prim_id) {
- case PL1_ENABLE:
- prim = POWER_LIMIT1;
- break;
- case PL2_ENABLE:
- prim = POWER_LIMIT2;
- break;
- case PL4_ENABLE:
- prim = POWER_LIMIT4;
- break;
- default:
- cpus_read_unlock();
- return -EINVAL;
- }
- if (rapl_read_data_raw(rd, prim, true, &val))
- ret = -EIO;
- else
+ ret = rapl_read_pl_data(rd, id, PL_LIMIT, true, &val);
+ if (!ret)
*data = val;

-get_exit:
cpus_read_unlock();

return ret;
@@ -427,23 +442,9 @@ static int set_time_window(struct powercap_zone *power_zone, int cid,
cpus_read_lock();
rd = power_zone_to_rapl_domain(power_zone);
id = contraint_to_pl(rd, cid);
- if (id < 0) {
- ret = id;
- goto set_time_exit;
- }

- switch (rd->rpl[id].prim_id) {
- case PL1_ENABLE:
- rapl_write_data_raw(rd, TIME_WINDOW1, window);
- break;
- case PL2_ENABLE:
- rapl_write_data_raw(rd, TIME_WINDOW2, window);
- break;
- default:
- ret = -EINVAL;
- }
+ ret = rapl_write_pl_data(rd, id, PL_TIME_WINDOW, window);

-set_time_exit:
cpus_read_unlock();
return ret;
}
@@ -459,33 +460,11 @@ static int get_time_window(struct powercap_zone *power_zone, int cid,
cpus_read_lock();
rd = power_zone_to_rapl_domain(power_zone);
id = contraint_to_pl(rd, cid);
- if (id < 0) {
- ret = id;
- goto get_time_exit;
- }

- switch (rd->rpl[id].prim_id) {
- case PL1_ENABLE:
- ret = rapl_read_data_raw(rd, TIME_WINDOW1, true, &val);
- break;
- case PL2_ENABLE:
- ret = rapl_read_data_raw(rd, TIME_WINDOW2, true, &val);
- break;
- case PL4_ENABLE:
- /*
- * Time window parameter is not applicable for PL4 entry
- * so assigining '0' as default value.
- */
- val = 0;
- break;
- default:
- cpus_read_unlock();
- return -EINVAL;
- }
+ ret = rapl_read_pl_data(rd, id, PL_TIME_WINDOW, true, &val);
if (!ret)
*data = val;

-get_time_exit:
cpus_read_unlock();

return ret;
@@ -505,36 +484,23 @@ static const char *get_constraint_name(struct powercap_zone *power_zone,
return NULL;
}

-static int get_max_power(struct powercap_zone *power_zone, int id, u64 *data)
+static int get_max_power(struct powercap_zone *power_zone, int cid, u64 *data)
{
struct rapl_domain *rd;
u64 val;
- int prim;
int ret = 0;
+ int id;

cpus_read_lock();
rd = power_zone_to_rapl_domain(power_zone);
- switch (rd->rpl[id].prim_id) {
- case PL1_ENABLE:
- prim = THERMAL_SPEC_POWER;
- break;
- case PL2_ENABLE:
- prim = MAX_POWER;
- break;
- case PL4_ENABLE:
- prim = MAX_POWER;
- break;
- default:
- cpus_read_unlock();
- return -EINVAL;
- }
- if (rapl_read_data_raw(rd, prim, true, &val))
- ret = -EIO;
- else
+ id = contraint_to_pl(rd, cid);
+
+ ret = rapl_read_pl_data(rd, id, PL_MAX_POWER, true, &val);
+ if (!ret)
*data = val;

/* As a generalization rule, PL4 would be around two times PL2. */
- if (rd->rpl[id].prim_id == PL4_ENABLE)
+ if (id == POWER_LIMIT4)
*data = *data * 2;

cpus_read_unlock();
@@ -560,6 +526,7 @@ static void rapl_init_domains(struct rapl_package *rp)

for (i = 0; i < RAPL_DOMAIN_MAX; i++) {
unsigned int mask = rp->domain_map & (1 << i);
+ int t;

if (!mask)
continue;
@@ -577,17 +544,10 @@ static void rapl_init_domains(struct rapl_package *rp)

/* PL1 is supported by default */
rp->priv->limits[i] |= BIT(POWER_LIMIT1);
- rd->rpl[0].prim_id = PL1_ENABLE;
- rd->rpl[0].name = pl1_name;

- if (rp->priv->limits[i] & BIT(POWER_LIMIT2)) {
- rd->rpl[1].prim_id = PL2_ENABLE;
- rd->rpl[1].name = pl2_name;
- }
-
- if (rp->priv->limits[i] & BIT(POWER_LIMIT4)) {
- rd->rpl[2].prim_id = PL4_ENABLE;
- rd->rpl[2].name = pl4_name;
+ for (t = POWER_LIMIT1; t < NR_POWER_LIMITS; t++) {
+ if (rp->priv->limits[i] & BIT(t))
+ rd->rpl[t].name = pl_names[t];
}

for (j = 0; j < RAPL_DOMAIN_REG_MAX; j++)
@@ -818,6 +778,33 @@ static int rapl_write_data_raw(struct rapl_domain *rd,
return ret;
}

+static int rapl_read_pl_data(struct rapl_domain *rd, int pl,
+ enum pl_prims pl_prim, bool xlate, u64 *data)
+{
+ enum rapl_primitives prim = get_pl_prim(pl, pl_prim);
+
+ if (!is_pl_valid(rd, pl))
+ return -EINVAL;
+
+ return rapl_read_data_raw(rd, prim, xlate, data);
+}
+
+static int rapl_write_pl_data(struct rapl_domain *rd, int pl,
+ enum pl_prims pl_prim,
+ unsigned long long value)
+{
+ enum rapl_primitives prim = get_pl_prim(pl, pl_prim);
+
+ if (!is_pl_valid(rd, pl))
+ return -EINVAL;
+
+ if (rd->state & DOMAIN_STATE_BIOS_LOCKED) {
+ pr_warn("%s:%s:%s locked by BIOS\n", rd->rp->name, rd->name, pl_names[pl]);
+ return -EACCES;
+ }
+
+ return rapl_write_data_raw(rd, prim, value);
+}
/*
* Raw RAPL data stored in MSRs are in certain scales. We need to
* convert them into standard units based on the units reported in
@@ -945,17 +932,16 @@ static void package_power_limit_irq_restore(struct rapl_package *rp)

static void set_floor_freq_default(struct rapl_domain *rd, bool mode)
{
- int nr_powerlimit = find_nr_power_limit(rd);
+ int i;

/* always enable clamp such that p-state can go below OS requested
* range. power capping priority over guranteed frequency.
*/
- rapl_write_data_raw(rd, PL1_CLAMP, mode);
+ rapl_write_pl_data(rd, POWER_LIMIT1, PL_CLAMP, mode);

- /* some domains have pl2 */
- if (nr_powerlimit > 1) {
- rapl_write_data_raw(rd, PL2_ENABLE, mode);
- rapl_write_data_raw(rd, PL2_CLAMP, mode);
+ for (i = POWER_LIMIT2; i < NR_POWER_LIMITS; i++) {
+ rapl_write_pl_data(rd, i, PL_ENABLE, mode);
+ rapl_write_pl_data(rd, i, PL_CLAMP, mode);
}
}

@@ -1327,11 +1313,10 @@ static void rapl_detect_powerlimit(struct rapl_domain *rd)
rd->state |= DOMAIN_STATE_BIOS_LOCKED;
}
}
- /* check if power limit MSR exists, otherwise domain is monitoring only */
- for (i = 0; i < NR_POWER_LIMITS; i++) {
- int prim = rd->rpl[i].prim_id;

- if (rapl_read_data_raw(rd, prim, false, &val64))
+ /* check if power limit exists, otherwise domain is monitoring only */
+ for (i = POWER_LIMIT1; i < NR_POWER_LIMITS; i++) {
+ if (rapl_read_pl_data(rd, i, PL_ENABLE, false, &val64))
rd->rpl[i].name = NULL;
}
}
@@ -1381,13 +1366,13 @@ void rapl_remove_package(struct rapl_package *rp)
package_power_limit_irq_restore(rp);

for (rd = rp->domains; rd < rp->domains + rp->nr_domains; rd++) {
- rapl_write_data_raw(rd, PL1_ENABLE, 0);
- rapl_write_data_raw(rd, PL1_CLAMP, 0);
- if (find_nr_power_limit(rd) > 1) {
- rapl_write_data_raw(rd, PL2_ENABLE, 0);
- rapl_write_data_raw(rd, PL2_CLAMP, 0);
- rapl_write_data_raw(rd, PL4_ENABLE, 0);
+ int i;
+
+ for (i = POWER_LIMIT1; i < NR_POWER_LIMITS; i++) {
+ rapl_write_pl_data(rd, i, PL_ENABLE, 0);
+ rapl_write_pl_data(rd, i, PL_CLAMP, 0);
}
+
if (rd->id == RAPL_DOMAIN_PACKAGE) {
rd_package = rd;
continue;
@@ -1472,38 +1457,18 @@ static void power_limit_state_save(void)
{
struct rapl_package *rp;
struct rapl_domain *rd;
- int nr_pl, ret, i;
+ int ret, i;

cpus_read_lock();
list_for_each_entry(rp, &rapl_packages, plist) {
if (!rp->power_zone)
continue;
rd = power_zone_to_rapl_domain(rp->power_zone);
- nr_pl = find_nr_power_limit(rd);
- for (i = 0; i < nr_pl; i++) {
- switch (rd->rpl[i].prim_id) {
- case PL1_ENABLE:
- ret = rapl_read_data_raw(rd,
- POWER_LIMIT1, true,
+ for (i = POWER_LIMIT1; i < NR_POWER_LIMITS; i++) {
+ ret = rapl_read_pl_data(rd, i, PL_LIMIT, true,
&rd->rpl[i].last_power_limit);
- if (ret)
- rd->rpl[i].last_power_limit = 0;
- break;
- case PL2_ENABLE:
- ret = rapl_read_data_raw(rd,
- POWER_LIMIT2, true,
- &rd->rpl[i].last_power_limit);
- if (ret)
- rd->rpl[i].last_power_limit = 0;
- break;
- case PL4_ENABLE:
- ret = rapl_read_data_raw(rd,
- POWER_LIMIT4, true,
- &rd->rpl[i].last_power_limit);
- if (ret)
- rd->rpl[i].last_power_limit = 0;
- break;
- }
+ if (ret)
+ rd->rpl[i].last_power_limit = 0;
}
}
cpus_read_unlock();
@@ -1513,33 +1478,17 @@ static void power_limit_state_restore(void)
{
struct rapl_package *rp;
struct rapl_domain *rd;
- int nr_pl, i;
+ int i;

cpus_read_lock();
list_for_each_entry(rp, &rapl_packages, plist) {
if (!rp->power_zone)
continue;
rd = power_zone_to_rapl_domain(rp->power_zone);
- nr_pl = find_nr_power_limit(rd);
- for (i = 0; i < nr_pl; i++) {
- switch (rd->rpl[i].prim_id) {
- case PL1_ENABLE:
- if (rd->rpl[i].last_power_limit)
- rapl_write_data_raw(rd, POWER_LIMIT1,
- rd->rpl[i].last_power_limit);
- break;
- case PL2_ENABLE:
- if (rd->rpl[i].last_power_limit)
- rapl_write_data_raw(rd, POWER_LIMIT2,
- rd->rpl[i].last_power_limit);
- break;
- case PL4_ENABLE:
- if (rd->rpl[i].last_power_limit)
- rapl_write_data_raw(rd, POWER_LIMIT4,
- rd->rpl[i].last_power_limit);
- break;
- }
- }
+ for (i = POWER_LIMIT1; i < NR_POWER_LIMITS; i++)
+ if (rd->rpl[i].last_power_limit)
+ rapl_write_pl_data(rd, i, PL_LIMIT,
+ rd->rpl[i].last_power_limit);
}
cpus_read_unlock();
}
diff --git a/include/linux/intel_rapl.h b/include/linux/intel_rapl.h
index 856b739fd194..86cd06bbea0c 100644
--- a/include/linux/intel_rapl.h
+++ b/include/linux/intel_rapl.h
@@ -79,7 +79,6 @@ struct rapl_domain_data {

struct rapl_power_limit {
struct powercap_zone_constraint *constraint;
- int prim_id; /* primitive ID used to enable */
struct rapl_domain *domain;
const char *name;
u64 last_power_limit;
--
2.25.1