On Monday 22 March 2010 19:38:38 Borislav Petkov wrote: > From: Borislav Petkov <borislav.petkov@xxxxxxx> > > 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, cleanup the driver init codepath and update copyrights. > > Signed-off-by: Borislav Petkov <borislav.petkov@xxxxxxx> > --- > arch/x86/kernel/cpu/cpufreq/powernow-k8.c | 115 ++++++++++++++++++++++++++--- > arch/x86/kernel/cpu/cpufreq/powernow-k8.h | 3 +- > 2 files changed, 106 insertions(+), 12 deletions(-) > > diff --git a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c > index d360b56..90fda2c 100644 > --- a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c > +++ b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c > @@ -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_disabled; Whatabout using a cpufeature (arch/x86/include/asm/cpufeature.h) instead of cpb_capable. Then people could see this feature in /proc/cpuinfo and other code parts could check for it easily if needed later. It could already be set in arch/x86/kernel/cpu/amd.c and powernow-k8 could use cpu_has(cpu, X86_FEATURE_CPB); Instead of cpb_disabled, I'd use cpb_enabled. Checking for !cpb_disabled whether it's enabled, is ugly to read. > +static struct msr __percpu *msrs; > + > #ifndef CONFIG_SMP > static inline const struct cpumask *cpu_core_mask(int cpu) > { > @@ -1393,8 +1396,69 @@ out: > return khz; > } > > +static void _cpb_toggle_msrs(bool t) > +{ > + int cpu; > + > + 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); > +} > + > +/* > + * Switch on/off core performance boosting. > + * > + * 0=disable > + * 1=enable. > + */ > +static void cpb_toggle(bool t) > +{ > + if (!cpb_capable) > + return; > + > + if (t && cpb_disabled) { > + cpb_disabled = false; cpb_enabled = true is better. > + _cpb_toggle_msrs(t); > + printk(KERN_INFO PFX "Core Boosting enabled.\n"); Always printk on every toggle? That should not happen often and a user might want to get noticed if an app does this behind his back -> should be fine w/ or w/o, just not sure whether it's intended. ... Thomas -- To unsubscribe from this list: send the line "unsubscribe cpufreq" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
