powernow-k8: Add core performance boost support
Starting with F10h, revE, AMD processors add support for a dynamic core boosting feature called Core Performance Boost. When a specific condition is present, a subset of the cores on a system are boosted beyond their P0 operating frequency to speed up the performance of single-threaded applications. In the normal case, the system comes out of reset with core boosting enabled. This patch adds a sysfs knob with which core boosting can be switched on or off for benchmarking purposes. While at it, make the CPB code hotplug-aware so that taking cores offline wouldn't interfere with boosting the remaining online cores. Furthermore, add cpu_online_mask hotplug protection as suggested by Andrew. Finally, cleanup the driver init codepath and update copyrights. Signed-off-by: Borislav Petkov <borislav.petkov@amd.com> LKML-Reference: <1270065406-1814-3-git-send-email-bp@amd64.org> Reviewed-by: Thomas Renninger <trenn@suse.de> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
This commit is contained in:
Borislav Petkov
H. Peter Anvin
parent
5958f1d5d7
commit
73860c6b2f
@ -1,6 +1,5 @@
|
||||
|
||||
/*
|
||||
* (c) 2003-2006 Advanced Micro Devices, Inc.
|
||||
* (c) 2003-2010 Advanced Micro Devices, Inc.
|
||||
* Your use of this code is subject to the terms and conditions of the
|
||||
* GNU general public license version 2. See "COPYING" or
|
||||
* http://www.gnu.org/licenses/gpl.html
|
||||
@ -54,6 +53,10 @@ static DEFINE_PER_CPU(struct powernow_k8_data *, powernow_data);
|
||||
|
||||
static int cpu_family = CPU_OPTERON;
|
||||
|
||||
/* core performance boost */
|
||||
static bool cpb_capable, cpb_enabled;
|
||||
static struct msr __percpu *msrs;
|
||||
|
||||
#ifndef CONFIG_SMP
|
||||
static inline const struct cpumask *cpu_core_mask(int cpu)
|
||||
{
|
||||
@ -1393,8 +1396,77 @@ static unsigned int powernowk8_get(unsigned int cpu)
|
||||
return khz;
|
||||
}
|
||||
|
||||
static void _cpb_toggle_msrs(bool t)
|
||||
{
|
||||
int cpu;
|
||||
|
||||
get_online_cpus();
|
||||
|
||||
rdmsr_on_cpus(cpu_online_mask, MSR_K7_HWCR, msrs);
|
||||
|
||||
for_each_cpu(cpu, cpu_online_mask) {
|
||||
struct msr *reg = per_cpu_ptr(msrs, cpu);
|
||||
if (t)
|
||||
reg->l &= ~BIT(25);
|
||||
else
|
||||
reg->l |= BIT(25);
|
||||
}
|
||||
wrmsr_on_cpus(cpu_online_mask, MSR_K7_HWCR, msrs);
|
||||
|
||||
put_online_cpus();
|
||||
}
|
||||
|
||||
/*
|
||||
* Switch on/off core performance boosting.
|
||||
*
|
||||
* 0=disable
|
||||
* 1=enable.
|
||||
*/
|
||||
static void cpb_toggle(bool t)
|
||||
{
|
||||
if (!cpb_capable)
|
||||
return;
|
||||
|
||||
if (t && !cpb_enabled) {
|
||||
cpb_enabled = true;
|
||||
_cpb_toggle_msrs(t);
|
||||
printk(KERN_INFO PFX "Core Boosting enabled.\n");
|
||||
} else if (!t && cpb_enabled) {
|
||||
cpb_enabled = false;
|
||||
_cpb_toggle_msrs(t);
|
||||
printk(KERN_INFO PFX "Core Boosting disabled.\n");
|
||||
}
|
||||
}
|
||||
|
||||
static ssize_t store_cpb(struct cpufreq_policy *policy, const char *buf,
|
||||
size_t count)
|
||||
{
|
||||
int ret = -EINVAL;
|
||||
unsigned long val = 0;
|
||||
|
||||
ret = strict_strtoul(buf, 10, &val);
|
||||
if (!ret && (val == 0 || val == 1) && cpb_capable)
|
||||
cpb_toggle(val);
|
||||
else
|
||||
return -EINVAL;
|
||||
|
||||
return count;
|
||||
}
|
||||
|
||||
static ssize_t show_cpb(struct cpufreq_policy *policy, char *buf)
|
||||
{
|
||||
return sprintf(buf, "%u\n", cpb_enabled);
|
||||
}
|
||||
|
||||
#define define_one_rw(_name) \
|
||||
static struct freq_attr _name = \
|
||||
__ATTR(_name, 0644, show_##_name, store_##_name)
|
||||
|
||||
define_one_rw(cpb);
|
||||
|
||||
static struct freq_attr *powernow_k8_attr[] = {
|
||||
&cpufreq_freq_attr_scaling_available_freqs,
|
||||
&cpb,
|
||||
NULL,
|
||||
};
|
||||
|
||||
@ -1410,10 +1482,51 @@ static struct cpufreq_driver cpufreq_amd64_driver = {
|
||||
.attr = powernow_k8_attr,
|
||||
};
|
||||
|
||||
/*
|
||||
* Clear the boost-disable flag on the CPU_DOWN path so that this cpu
|
||||
* cannot block the remaining ones from boosting. On the CPU_UP path we
|
||||
* simply keep the boost-disable flag in sync with the current global
|
||||
* state.
|
||||
*/
|
||||
static int __cpuinit cpb_notify(struct notifier_block *nb, unsigned long action,
|
||||
void *hcpu)
|
||||
{
|
||||
unsigned cpu = (long)hcpu;
|
||||
u32 lo, hi;
|
||||
|
||||
switch (action) {
|
||||
case CPU_UP_PREPARE:
|
||||
case CPU_UP_PREPARE_FROZEN:
|
||||
|
||||
if (!cpb_enabled) {
|
||||
rdmsr_on_cpu(cpu, MSR_K7_HWCR, &lo, &hi);
|
||||
lo |= BIT(25);
|
||||
wrmsr_on_cpu(cpu, MSR_K7_HWCR, lo, hi);
|
||||
}
|
||||
break;
|
||||
|
||||
case CPU_DOWN_PREPARE:
|
||||
case CPU_DOWN_PREPARE_FROZEN:
|
||||
rdmsr_on_cpu(cpu, MSR_K7_HWCR, &lo, &hi);
|
||||
lo &= ~BIT(25);
|
||||
wrmsr_on_cpu(cpu, MSR_K7_HWCR, lo, hi);
|
||||
break;
|
||||
|
||||
default:
|
||||
break;
|
||||
}
|
||||
|
||||
return NOTIFY_OK;
|
||||
}
|
||||
|
||||
static struct notifier_block __cpuinitdata cpb_nb = {
|
||||
.notifier_call = cpb_notify,
|
||||
};
|
||||
|
||||
/* driver entry point for init */
|
||||
static int __cpuinit powernowk8_init(void)
|
||||
{
|
||||
unsigned int i, supported_cpus = 0;
|
||||
unsigned int i, supported_cpus = 0, cpu;
|
||||
|
||||
for_each_online_cpu(i) {
|
||||
int rc;
|
||||
@ -1422,15 +1535,36 @@ static int __cpuinit powernowk8_init(void)
|
||||
supported_cpus++;
|
||||
}
|
||||
|
||||
if (supported_cpus == num_online_cpus()) {
|
||||
printk(KERN_INFO PFX "Found %d %s "
|
||||
"processors (%d cpu cores) (" VERSION ")\n",
|
||||
num_online_nodes(),
|
||||
boot_cpu_data.x86_model_id, supported_cpus);
|
||||
return cpufreq_register_driver(&cpufreq_amd64_driver);
|
||||
if (supported_cpus != num_online_cpus())
|
||||
return -ENODEV;
|
||||
|
||||
printk(KERN_INFO PFX "Found %d %s (%d cpu cores) (" VERSION ")\n",
|
||||
num_online_nodes(), boot_cpu_data.x86_model_id, supported_cpus);
|
||||
|
||||
if (boot_cpu_has(X86_FEATURE_CPB)) {
|
||||
|
||||
cpb_capable = true;
|
||||
|
||||
register_cpu_notifier(&cpb_nb);
|
||||
|
||||
msrs = msrs_alloc();
|
||||
if (!msrs) {
|
||||
printk(KERN_ERR "%s: Error allocating msrs!\n", __func__);
|
||||
return -ENOMEM;
|
||||
}
|
||||
|
||||
rdmsr_on_cpus(cpu_online_mask, MSR_K7_HWCR, msrs);
|
||||
|
||||
for_each_cpu(cpu, cpu_online_mask) {
|
||||
struct msr *reg = per_cpu_ptr(msrs, cpu);
|
||||
cpb_enabled |= !(!!(reg->l & BIT(25)));
|
||||
}
|
||||
|
||||
printk(KERN_INFO PFX "Core Performance Boosting: %s.\n",
|
||||
(cpb_enabled ? "on" : "off"));
|
||||
}
|
||||
|
||||
return -ENODEV;
|
||||
return cpufreq_register_driver(&cpufreq_amd64_driver);
|
||||
}
|
||||
|
||||
/* driver entry point for term */
|
||||
@ -1438,6 +1572,13 @@ static void __exit powernowk8_exit(void)
|
||||
{
|
||||
dprintk("exit\n");
|
||||
|
||||
if (boot_cpu_has(X86_FEATURE_CPB)) {
|
||||
msrs_free(msrs);
|
||||
msrs = NULL;
|
||||
|
||||
unregister_cpu_notifier(&cpb_nb);
|
||||
}
|
||||
|
||||
cpufreq_unregister_driver(&cpufreq_amd64_driver);
|
||||
}
|
||||
|
||||
|
||||
@ -5,7 +5,6 @@
|
||||
* http://www.gnu.org/licenses/gpl.html
|
||||
*/
|
||||
|
||||
|
||||
enum pstate {
|
||||
HW_PSTATE_INVALID = 0xff,
|
||||
HW_PSTATE_0 = 0,
|
||||
@ -55,7 +54,6 @@ struct powernow_k8_data {
|
||||
struct cpumask *available_cores;
|
||||
};
|
||||
|
||||
|
||||
/* processor's cpuid instruction support */
|
||||
#define CPUID_PROCESSOR_SIGNATURE 1 /* function 1 */
|
||||
#define CPUID_XFAM 0x0ff00000 /* extended family */
|
||||
|
||||
Loading…
Reference in New Issue
Block a user