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Date: Thu, 05 Mar 2009 17:27:23 +1030
From: Rusty Russell <rusty@...tcorp.com.au>
To: Ingo Molnar <mingo@...hat.com>
Cc: Andrew Morton <akpm@...ux-foundation.org>
Subject: [PATCH 2/10] use smp_call_function_single() in arch/x86/kernel/acpi/cstate.c
From: Andrew Morton <akpm@...ux-foundation.org>
Attempting to rid us of the problematic work_on_cpu(). Just use
smp_call_function_single() here.
Cc: Ingo Molnar <mingo@...e.hu>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@...el.com>
Cc: Len Brown <len.brown@...el.com>
Cc: Zhao Yakui <yakui.zhao@...el.com>
Signed-off-by: Andrew Morton <akpm@...ux-foundation.org>
Signed-off-by: Rusty Russell <rusty@...tcorp.com.au>
---
arch/x86/kernel/acpi/cstate.c | 36 ++++++++++++++++++++++++------------
1 file changed, 24 insertions(+), 12 deletions(-)
diff -puN arch/x86/kernel/acpi/cstate.c~arch-x86-kernel-acpi-cstatec-avoid-using-work_on_cpu arch/x86/kernel/acpi/cstate.c
--- a/arch/x86/kernel/acpi/cstate.c~arch-x86-kernel-acpi-cstatec-avoid-using-work_on_cpu
+++ a/arch/x86/kernel/acpi/cstate.c
@@ -61,6 +61,12 @@ struct cstate_entry {
};
static struct cstate_entry *cpu_cstate_entry; /* per CPU ptr */
+/* Used for the cross-CPU calls */
+struct acpi_processor_cx_cross_cpu {
+ struct acpi_processor_cx *cx;
+ long retval;
+};
+
static short mwait_supported[ACPI_PROCESSOR_MAX_POWER];
#define MWAIT_SUBSTATE_MASK (0xf)
@@ -75,10 +81,10 @@ static short mwait_supported[ACPI_PROCES
#define NATIVE_CSTATE_BEYOND_HALT (2)
-static long acpi_processor_ffh_cstate_probe_cpu(void *_cx)
+static void acpi_processor_ffh_cstate_probe_cpu(void *_cxcc)
{
- struct acpi_processor_cx *cx = _cx;
- long retval;
+ struct acpi_processor_cx_cross_cpu *cxcc = _cxcc;
+ struct acpi_processor_cx *cx = cxcc->cx;
unsigned int eax, ebx, ecx, edx;
unsigned int edx_part;
unsigned int cstate_type; /* C-state type and not ACPI C-state type */
@@ -92,16 +98,16 @@ static long acpi_processor_ffh_cstate_pr
edx_part = edx >> (cstate_type * MWAIT_SUBSTATE_SIZE);
num_cstate_subtype = edx_part & MWAIT_SUBSTATE_MASK;
- retval = 0;
+ cxcc->retval = 0;
if (num_cstate_subtype < (cx->address & MWAIT_SUBSTATE_MASK)) {
- retval = -1;
+ cxcc->retval = -1;
goto out;
}
/* mwait ecx extensions INTERRUPT_BREAK should be supported for C2/C3 */
if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) ||
!(ecx & CPUID5_ECX_INTERRUPT_BREAK)) {
- retval = -1;
+ cxcc->retval = -1;
goto out;
}
@@ -115,7 +121,7 @@ static long acpi_processor_ffh_cstate_pr
ACPI_CX_DESC_LEN, "ACPI FFH INTEL MWAIT 0x%x",
cx->address);
out:
- return retval;
+ return;
}
int acpi_processor_ffh_cstate_probe(unsigned int cpu,
@@ -123,6 +129,7 @@ int acpi_processor_ffh_cstate_probe(unsi
{
struct cstate_entry *percpu_entry;
struct cpuinfo_x86 *c = &cpu_data(cpu);
+ struct acpi_processor_cx_cross_cpu cxcc = { .cx = cx, };
long retval;
if (!cpu_cstate_entry || c->cpuid_level < CPUID_MWAIT_LEAF)
@@ -135,13 +142,18 @@ int acpi_processor_ffh_cstate_probe(unsi
percpu_entry->states[cx->index].eax = 0;
percpu_entry->states[cx->index].ecx = 0;
- /* Make sure we are running on right CPU */
+ /* Run acpi_processor_ffh_cstate_probe_cpu() on the target CPU */
- retval = work_on_cpu(cpu, acpi_processor_ffh_cstate_probe_cpu, cx);
+ retval = smp_call_function_single(cpu,
+ acpi_processor_ffh_cstate_probe_cpu, cx, 1);
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;
+ retval = cxcc.retval;
+ 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;
}
_
--
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