summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
Diffstat
-rw-r--r--Documentation/kernel-parameters.txt11
-rw-r--r--arch/x86/include/asm/processor.h18
-rw-r--r--arch/x86/kernel/cpu/bugs.c27
-rw-r--r--arch/x86/kernel/cpu/proc.c2
-rw-r--r--arch/x86/kernel/process.c89
-rw-r--r--arch/x86/kernel/smpboot.c2
-rw-r--r--arch/x86/xen/setup.c5
-rw-r--r--drivers/acpi/processor_idle.c1
8 files changed, 15 insertions, 140 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 363e348bff9..109ee45cf20 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1039,16 +1039,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
Claim all unknown PCI IDE storage controllers.
idle= [X86]
- Format: idle=poll, idle=mwait, idle=halt, idle=nomwait
+ Format: idle=poll, idle=halt, idle=nomwait
Poll forces a polling idle loop that can slightly
improve the performance of waking up a idle CPU, but
will use a lot of power and make the system run hot.
Not recommended.
- idle=mwait: On systems which support MONITOR/MWAIT but
- the kernel chose to not use it because it doesn't save
- as much power as a normal idle loop, use the
- MONITOR/MWAIT idle loop anyways. Performance should be
- the same as idle=poll.
idle=halt: Halt is forced to be used for CPU idle.
In such case C2/C3 won't be used again.
idle=nomwait: Disable mwait for CPU C-states
@@ -1886,10 +1881,6 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
wfi(ARM) instruction doesn't work correctly and not to
use it. This is also useful when using JTAG debugger.
- no-hlt [BUGS=X86-32] Tells the kernel that the hlt
- instruction doesn't work correctly and not to
- use it.
-
no_file_caps Tells the kernel not to honor file capabilities. The
only way then for a file to be executed with privilege
is to be setuid root or executed by root.
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 888184b2fc8..b9e7d279f8e 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -89,7 +89,6 @@ struct cpuinfo_x86 {
char wp_works_ok; /* It doesn't on 386's */
/* Problems on some 486Dx4's and old 386's: */
- char hlt_works_ok;
char hard_math;
char rfu;
char fdiv_bug;
@@ -165,15 +164,6 @@ DECLARE_PER_CPU_SHARED_ALIGNED(struct cpuinfo_x86, cpu_info);
extern const struct seq_operations cpuinfo_op;
-static inline int hlt_works(int cpu)
-{
-#ifdef CONFIG_X86_32
- return cpu_data(cpu).hlt_works_ok;
-#else
- return 1;
-#endif
-}
-
#define cache_line_size() (boot_cpu_data.x86_cache_alignment)
extern void cpu_detect(struct cpuinfo_x86 *c);
@@ -725,7 +715,7 @@ extern unsigned long boot_option_idle_override;
extern bool amd_e400_c1e_detected;
enum idle_boot_override {IDLE_NO_OVERRIDE=0, IDLE_HALT, IDLE_NOMWAIT,
- IDLE_POLL, IDLE_FORCE_MWAIT};
+ IDLE_POLL};
extern void enable_sep_cpu(void);
extern int sysenter_setup(void);
@@ -998,7 +988,11 @@ extern unsigned long arch_align_stack(unsigned long sp);
extern void free_init_pages(char *what, unsigned long begin, unsigned long end);
void default_idle(void);
-bool set_pm_idle_to_default(void);
+#ifdef CONFIG_XEN
+bool xen_set_default_idle(void);
+#else
+#define xen_set_default_idle 0
+#endif
void stop_this_cpu(void *dummy);
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 92dfec986a4..af6455e3fcc 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -17,15 +17,6 @@
#include <asm/paravirt.h>
#include <asm/alternative.h>
-static int __init no_halt(char *s)
-{
- WARN_ONCE(1, "\"no-hlt\" is deprecated, please use \"idle=poll\"\n");
- boot_cpu_data.hlt_works_ok = 0;
- return 1;
-}
-
-__setup("no-hlt", no_halt);
-
static int __init no_387(char *s)
{
boot_cpu_data.hard_math = 0;
@@ -89,23 +80,6 @@ static void __init check_fpu(void)
pr_warn("Hmm, FPU with FDIV bug\n");
}
-static void __init check_hlt(void)
-{
- if (boot_cpu_data.x86 >= 5 || paravirt_enabled())
- return;
-
- pr_info("Checking 'hlt' instruction... ");
- if (!boot_cpu_data.hlt_works_ok) {
- pr_cont("disabled\n");
- return;
- }
- halt();
- halt();
- halt();
- halt();
- pr_cont("OK\n");
-}
-
/*
* Check whether we are able to run this kernel safely on SMP.
*
@@ -129,7 +103,6 @@ void __init check_bugs(void)
print_cpu_info(&boot_cpu_data);
#endif
check_config();
- check_hlt();
init_utsname()->machine[1] =
'0' + (boot_cpu_data.x86 > 6 ? 6 : boot_cpu_data.x86);
alternative_instructions();
diff --git a/arch/x86/kernel/cpu/proc.c b/arch/x86/kernel/cpu/proc.c
index 3286a92e662..e280253f6f9 100644
--- a/arch/x86/kernel/cpu/proc.c
+++ b/arch/x86/kernel/cpu/proc.c
@@ -28,7 +28,6 @@ static void show_cpuinfo_misc(struct seq_file *m, struct cpuinfo_x86 *c)
{
seq_printf(m,
"fdiv_bug\t: %s\n"
- "hlt_bug\t\t: %s\n"
"f00f_bug\t: %s\n"
"coma_bug\t: %s\n"
"fpu\t\t: %s\n"
@@ -36,7 +35,6 @@ static void show_cpuinfo_misc(struct seq_file *m, struct cpuinfo_x86 *c)
"cpuid level\t: %d\n"
"wp\t\t: %s\n",
c->fdiv_bug ? "yes" : "no",
- c->hlt_works_ok ? "no" : "yes",
c->f00f_bug ? "yes" : "no",
c->coma_bug ? "yes" : "no",
c->hard_math ? "yes" : "no",
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index ceb05db59be..b11719ea2f7 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -390,7 +390,8 @@ void default_idle(void)
EXPORT_SYMBOL(default_idle);
#endif
-bool set_pm_idle_to_default(void)
+#ifdef CONFIG_XEN
+bool xen_set_default_idle(void)
{
bool ret = !!x86_idle;
@@ -398,6 +399,7 @@ bool set_pm_idle_to_default(void)
return ret;
}
+#endif
void stop_this_cpu(void *dummy)
{
local_irq_disable();
@@ -407,31 +409,8 @@ void stop_this_cpu(void *dummy)
set_cpu_online(smp_processor_id(), false);
disable_local_APIC();
- for (;;) {
- if (hlt_works(smp_processor_id()))
- halt();
- }
-}
-
-/* Default MONITOR/MWAIT with no hints, used for default C1 state */
-static void mwait_idle(void)
-{
- if (!need_resched()) {
- trace_power_start_rcuidle(POWER_CSTATE, 1, smp_processor_id());
- trace_cpu_idle_rcuidle(1, smp_processor_id());
- if (this_cpu_has(X86_FEATURE_CLFLUSH_MONITOR))
- clflush((void *)&current_thread_info()->flags);
-
- __monitor((void *)&current_thread_info()->flags, 0, 0);
- smp_mb();
- if (!need_resched())
- __sti_mwait(0, 0);
- else
- local_irq_enable();
- trace_power_end_rcuidle(smp_processor_id());
- trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
- } else
- local_irq_enable();
+ for (;;)
+ halt();
}
/*
@@ -450,53 +429,6 @@ static void poll_idle(void)
trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
}
-/*
- * mwait selection logic:
- *
- * It depends on the CPU. For AMD CPUs that support MWAIT this is
- * wrong. Family 0x10 and 0x11 CPUs will enter C1 on HLT. Powersavings
- * then depend on a clock divisor and current Pstate of the core. If
- * all cores of a processor are in halt state (C1) the processor can
- * enter the C1E (C1 enhanced) state. If mwait is used this will never
- * happen.
- *
- * idle=mwait overrides this decision and forces the usage of mwait.
- */
-
-#define MWAIT_INFO 0x05
-#define MWAIT_ECX_EXTENDED_INFO 0x01
-#define MWAIT_EDX_C1 0xf0
-
-int mwait_usable(const struct cpuinfo_x86 *c)
-{
- u32 eax, ebx, ecx, edx;
-
- /* Use mwait if idle=mwait boot option is given */
- if (boot_option_idle_override == IDLE_FORCE_MWAIT)
- return 1;
-
- /*
- * Any idle= boot option other than idle=mwait means that we must not
- * use mwait. Eg: idle=halt or idle=poll or idle=nomwait
- */
- if (boot_option_idle_override != IDLE_NO_OVERRIDE)
- return 0;
-
- if (c->cpuid_level < MWAIT_INFO)
- return 0;
-
- cpuid(MWAIT_INFO, &eax, &ebx, &ecx, &edx);
- /* Check, whether EDX has extended info about MWAIT */
- if (!(ecx & MWAIT_ECX_EXTENDED_INFO))
- return 1;
-
- /*
- * edx enumeratios MONITOR/MWAIT extensions. Check, whether
- * C1 supports MWAIT
- */
- return (edx & MWAIT_EDX_C1);
-}
-
bool amd_e400_c1e_detected;
EXPORT_SYMBOL(amd_e400_c1e_detected);
@@ -567,13 +499,7 @@ void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c)
if (x86_idle)
return;
- if (cpu_has(c, X86_FEATURE_MWAIT) && mwait_usable(c)) {
- /*
- * One CPU supports mwait => All CPUs supports mwait
- */
- pr_info("using mwait in idle threads\n");
- x86_idle = mwait_idle;
- } else if (cpu_has_amd_erratum(amd_erratum_400)) {
+ if (cpu_has_amd_erratum(amd_erratum_400)) {
/* E400: APIC timer interrupt does not wake up CPU from C1e */
pr_info("using AMD E400 aware idle routine\n");
x86_idle = amd_e400_idle;
@@ -597,9 +523,6 @@ static int __init idle_setup(char *str)
pr_info("using polling idle threads\n");
x86_idle = poll_idle;
boot_option_idle_override = IDLE_POLL;
- } else if (!strcmp(str, "mwait")) {
- boot_option_idle_override = IDLE_FORCE_MWAIT;
- WARN_ONCE(1, "\"idle=mwait\" will be removed in 2012\n");
} else if (!strcmp(str, "halt")) {
/*
* When the boot option of idle=halt is added, halt is
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index ed0fe385289..a6ceaedc396 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1369,7 +1369,7 @@ static inline void mwait_play_dead(void)
void *mwait_ptr;
struct cpuinfo_x86 *c = __this_cpu_ptr(&cpu_info);
- if (!(this_cpu_has(X86_FEATURE_MWAIT) && mwait_usable(c)))
+ if (!this_cpu_has(X86_FEATURE_MWAIT))
return;
if (!this_cpu_has(X86_FEATURE_CLFLSH))
return;
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index 8971a26d21a..94eac5c85cd 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -556,12 +556,9 @@ void __init xen_arch_setup(void)
COMMAND_LINE_SIZE : MAX_GUEST_CMDLINE);
/* Set up idle, making sure it calls safe_halt() pvop */
-#ifdef CONFIG_X86_32
- boot_cpu_data.hlt_works_ok = 1;
-#endif
disable_cpuidle();
disable_cpufreq();
- WARN_ON(set_pm_idle_to_default());
+ WARN_ON(xen_set_default_idle());
fiddle_vdso();
#ifdef CONFIG_NUMA
numa_off = 1;
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 8b433cb08a3..fc95308e9a1 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -71,7 +71,6 @@ static struct acpi_processor_cx *acpi_cstate[CPUIDLE_STATE_MAX];
static int disabled_by_idle_boot_param(void)
{
return boot_option_idle_override == IDLE_POLL ||
- boot_option_idle_override == IDLE_FORCE_MWAIT ||
boot_option_idle_override == IDLE_HALT;
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-11 05:18:20 +0000