From c74f31c035f46a095a0c72f80246a65b314205a5 Mon Sep 17 00:00:00 2001 From: Mike Travis Date: Sun, 4 Jan 2009 05:18:07 -0800 Subject: [PATCH] cpumask: use work_on_cpu in acpi/cstate.c Impact: use new cpumask API to reduce stack usage Replace the saving of current->cpus_allowed and set_cpus_allowed_ptr() with a work_on_cpu function for the acpi_processor_ffh_cstate_probe() function. Basically splits acpi_processor_ffh_cstate_probe() into two functions, the other being acpi_processor_ffh_cstate_probe_cpu which is the work function run on the designated cpu. Signed-off-by: Mike Travis Acked-by: Rusty Russell Signed-off-by: Ingo Molnar --- arch/x86/kernel/acpi/cstate.c | 70 ++++++++++++++++++----------------- 1 file changed, 37 insertions(+), 33 deletions(-) diff --git a/arch/x86/kernel/acpi/cstate.c b/arch/x86/kernel/acpi/cstate.c index c2502eb9aa8..cf5ec586f22 100644 --- a/arch/x86/kernel/acpi/cstate.c +++ b/arch/x86/kernel/acpi/cstate.c @@ -66,35 +66,15 @@ static short mwait_supported[ACPI_PROCESSOR_MAX_POWER]; #define NATIVE_CSTATE_BEYOND_HALT (2) -int acpi_processor_ffh_cstate_probe(unsigned int cpu, - struct acpi_processor_cx *cx, struct acpi_power_register *reg) +static long acpi_processor_ffh_cstate_probe_cpu(void *_cx) { - struct cstate_entry *percpu_entry; - struct cpuinfo_x86 *c = &cpu_data(cpu); - - cpumask_t saved_mask; - int retval; + struct acpi_processor_cx *cx = _cx; + long retval; unsigned int eax, ebx, ecx, edx; unsigned int edx_part; unsigned int cstate_type; /* C-state type and not ACPI C-state type */ unsigned int num_cstate_subtype; - if (!cpu_cstate_entry || c->cpuid_level < CPUID_MWAIT_LEAF ) - return -1; - - if (reg->bit_offset != NATIVE_CSTATE_BEYOND_HALT) - return -1; - - percpu_entry = per_cpu_ptr(cpu_cstate_entry, cpu); - percpu_entry->states[cx->index].eax = 0; - percpu_entry->states[cx->index].ecx = 0; - - /* Make sure we are running on right CPU */ - saved_mask = current->cpus_allowed; - retval = set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu)); - if (retval) - return -1; - cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &edx); /* Check whether this particular cx_type (in CST) is supported or not */ @@ -114,21 +94,45 @@ int acpi_processor_ffh_cstate_probe(unsigned int cpu, retval = -1; goto out; } - percpu_entry->states[cx->index].ecx = MWAIT_ECX_INTERRUPT_BREAK; - - /* Use the hint in CST */ - percpu_entry->states[cx->index].eax = cx->address; if (!mwait_supported[cstate_type]) { mwait_supported[cstate_type] = 1; - printk(KERN_DEBUG "Monitor-Mwait will be used to enter C-%d " - "state\n", cx->type); + printk(KERN_DEBUG + "Monitor-Mwait will be used to enter C-%d " + "state\n", cx->type); } - snprintf(cx->desc, ACPI_CX_DESC_LEN, "ACPI FFH INTEL MWAIT 0x%x", - cx->address); - + snprintf(cx->desc, + ACPI_CX_DESC_LEN, "ACPI FFH INTEL MWAIT 0x%x", + cx->address); out: - set_cpus_allowed_ptr(current, &saved_mask); + return retval; +} + +int acpi_processor_ffh_cstate_probe(unsigned int cpu, + struct acpi_processor_cx *cx, struct acpi_power_register *reg) +{ + struct cstate_entry *percpu_entry; + struct cpuinfo_x86 *c = &cpu_data(cpu); + long retval; + + if (!cpu_cstate_entry || c->cpuid_level < CPUID_MWAIT_LEAF) + return -1; + + if (reg->bit_offset != NATIVE_CSTATE_BEYOND_HALT) + return -1; + + percpu_entry = per_cpu_ptr(cpu_cstate_entry, cpu); + percpu_entry->states[cx->index].eax = 0; + percpu_entry->states[cx->index].ecx = 0; + + /* Make sure we are running on right CPU */ + + retval = work_on_cpu(cpu, acpi_processor_ffh_cstate_probe_cpu, cx); + if (retval == 0) { + /* Use the hint in CST */ + percpu_entry->states[cx->index].eax = cx->address; + percpu_entry->states[cx->index].ecx = MWAIT_ECX_INTERRUPT_BREAK; + } return retval; } EXPORT_SYMBOL_GPL(acpi_processor_ffh_cstate_probe); -- 2.41.1