powercap/rapl: reduce ipi calls

Reduce remote CPU calls for MSR access by combining read
modify write into one function.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Jacob Pan 2016-02-24 13:31:36 -08:00 committed by Rafael J. Wysocki
parent 16ccbd87c2
commit f14a1396d8

View File

@ -133,6 +133,12 @@ struct rapl_domain_data {
unsigned long timestamp;
};
struct msrl_action {
u32 msr_no;
u64 clear_mask;
u64 set_mask;
int err;
};
#define DOMAIN_STATE_INACTIVE BIT(0)
#define DOMAIN_STATE_POWER_LIMIT_SET BIT(1)
@ -800,35 +806,62 @@ static int rapl_read_data_raw(struct rapl_domain *rd,
return 0;
}
static int msrl_update_safe(u32 msr_no, u64 clear_mask, u64 set_mask)
{
int err;
u64 val;
err = rdmsrl_safe(msr_no, &val);
if (err)
goto out;
val &= ~clear_mask;
val |= set_mask;
err = wrmsrl_safe(msr_no, val);
out:
return err;
}
static void msrl_update_func(void *info)
{
struct msrl_action *ma = info;
ma->err = msrl_update_safe(ma->msr_no, ma->clear_mask, ma->set_mask);
}
/* Similar use of primitive info in the read counterpart */
static int rapl_write_data_raw(struct rapl_domain *rd,
enum rapl_primitives prim,
unsigned long long value)
{
u64 msr_val;
u32 msr;
struct rapl_primitive_info *rp = &rpi[prim];
int cpu;
u64 bits;
struct msrl_action ma;
int ret;
cpu = find_active_cpu_on_package(rd->package_id);
if (cpu < 0)
return cpu;
msr = rd->msrs[rp->id];
if (rdmsrl_safe_on_cpu(cpu, msr, &msr_val)) {
dev_dbg(&rd->power_zone.dev,
"failed to read msr 0x%x on cpu %d\n", msr, cpu);
return -EIO;
}
value = rapl_unit_xlate(rd, rd->package_id, rp->unit, value, 1);
msr_val &= ~rp->mask;
msr_val |= value << rp->shift;
if (wrmsrl_safe_on_cpu(cpu, msr, msr_val)) {
dev_dbg(&rd->power_zone.dev,
"failed to write msr 0x%x on cpu %d\n", msr, cpu);
return -EIO;
}
return 0;
bits = rapl_unit_xlate(rd, rd->package_id, rp->unit, value, 1);
bits |= bits << rp->shift;
memset(&ma, 0, sizeof(ma));
ma.msr_no = rd->msrs[rp->id];
ma.clear_mask = rp->mask;
ma.set_mask = bits;
ret = smp_call_function_single(cpu, msrl_update_func, &ma, 1);
if (ret)
WARN_ON_ONCE(ret);
else
ret = ma.err;
return ret;
}
/*
@ -893,6 +926,21 @@ static int rapl_check_unit_atom(struct rapl_package *rp, int cpu)
return 0;
}
static void power_limit_irq_save_cpu(void *info)
{
u32 l, h = 0;
struct rapl_package *rp = (struct rapl_package *)info;
/* save the state of PLN irq mask bit before disabling it */
rdmsr_safe(MSR_IA32_PACKAGE_THERM_INTERRUPT, &l, &h);
if (!(rp->power_limit_irq & PACKAGE_PLN_INT_SAVED)) {
rp->power_limit_irq = l & PACKAGE_THERM_INT_PLN_ENABLE;
rp->power_limit_irq |= PACKAGE_PLN_INT_SAVED;
}
l &= ~PACKAGE_THERM_INT_PLN_ENABLE;
wrmsr_safe(MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h);
}
/* REVISIT:
* When package power limit is set artificially low by RAPL, LVT
@ -906,7 +954,6 @@ static int rapl_check_unit_atom(struct rapl_package *rp, int cpu)
static void package_power_limit_irq_save(int package_id)
{
u32 l, h = 0;
int cpu;
struct rapl_package *rp;
@ -920,20 +967,30 @@ static void package_power_limit_irq_save(int package_id)
cpu = find_active_cpu_on_package(package_id);
if (cpu < 0)
return;
/* save the state of PLN irq mask bit before disabling it */
rdmsr_safe_on_cpu(cpu, MSR_IA32_PACKAGE_THERM_INTERRUPT, &l, &h);
if (!(rp->power_limit_irq & PACKAGE_PLN_INT_SAVED)) {
rp->power_limit_irq = l & PACKAGE_THERM_INT_PLN_ENABLE;
rp->power_limit_irq |= PACKAGE_PLN_INT_SAVED;
}
l &= ~PACKAGE_THERM_INT_PLN_ENABLE;
wrmsr_on_cpu(cpu, MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h);
if (!boot_cpu_has(X86_FEATURE_PTS) || !boot_cpu_has(X86_FEATURE_PLN))
return;
smp_call_function_single(cpu, power_limit_irq_save_cpu, rp, 1);
}
static void power_limit_irq_restore_cpu(void *info)
{
u32 l, h = 0;
struct rapl_package *rp = (struct rapl_package *)info;
rdmsr_safe(MSR_IA32_PACKAGE_THERM_INTERRUPT, &l, &h);
if (rp->power_limit_irq & PACKAGE_THERM_INT_PLN_ENABLE)
l |= PACKAGE_THERM_INT_PLN_ENABLE;
else
l &= ~PACKAGE_THERM_INT_PLN_ENABLE;
wrmsr_safe(MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h);
}
/* restore per package power limit interrupt enable state */
static void package_power_limit_irq_restore(int package_id)
{
u32 l, h;
int cpu;
struct rapl_package *rp;
@ -951,14 +1008,8 @@ static void package_power_limit_irq_restore(int package_id)
/* irq enable state not saved, nothing to restore */
if (!(rp->power_limit_irq & PACKAGE_PLN_INT_SAVED))
return;
rdmsr_safe_on_cpu(cpu, MSR_IA32_PACKAGE_THERM_INTERRUPT, &l, &h);
if (rp->power_limit_irq & PACKAGE_THERM_INT_PLN_ENABLE)
l |= PACKAGE_THERM_INT_PLN_ENABLE;
else
l &= ~PACKAGE_THERM_INT_PLN_ENABLE;
wrmsr_on_cpu(cpu, MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h);
smp_call_function_single(cpu, power_limit_irq_restore_cpu, rp, 1);
}
static void set_floor_freq_default(struct rapl_domain *rd, bool mode)