linux/include/asm-x86/irqflags.h

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#ifndef _X86_IRQFLAGS_H_
#define _X86_IRQFLAGS_H_
#include <asm/processor-flags.h>
#ifndef __ASSEMBLY__
/*
* Interrupt control:
*/
static inline unsigned long native_save_fl(void)
{
unsigned long flags;
asm volatile("# __raw_save_flags\n\t"
"pushf ; pop %0"
: "=g" (flags)
: /* no input */
: "memory");
return flags;
}
static inline void native_restore_fl(unsigned long flags)
{
asm volatile("push %0 ; popf"
: /* no output */
:"g" (flags)
:"memory", "cc");
}
static inline void native_irq_disable(void)
{
asm volatile("cli": : :"memory");
}
static inline void native_irq_enable(void)
{
asm volatile("sti": : :"memory");
}
static inline void native_safe_halt(void)
{
asm volatile("sti; hlt": : :"memory");
}
static inline void native_halt(void)
{
asm volatile("hlt": : :"memory");
}
#endif
#ifdef CONFIG_PARAVIRT
#include <asm/paravirt.h>
#else
#ifndef __ASSEMBLY__
static inline unsigned long __raw_local_save_flags(void)
{
return native_save_fl();
}
static inline void raw_local_irq_restore(unsigned long flags)
{
native_restore_fl(flags);
}
static inline void raw_local_irq_disable(void)
{
native_irq_disable();
}
static inline void raw_local_irq_enable(void)
{
native_irq_enable();
}
/*
* Used in the idle loop; sti takes one instruction cycle
* to complete:
*/
static inline void raw_safe_halt(void)
{
native_safe_halt();
}
/*
* Used when interrupts are already enabled or to
* shutdown the processor:
*/
static inline void halt(void)
{
native_halt();
}
/*
* For spinlocks, etc:
*/
static inline unsigned long __raw_local_irq_save(void)
{
unsigned long flags = __raw_local_save_flags();
raw_local_irq_disable();
return flags;
}
#else
#define ENABLE_INTERRUPTS(x) sti
#define DISABLE_INTERRUPTS(x) cli
#ifdef CONFIG_X86_64
#define SWAPGS swapgs
/*
* Currently paravirt can't handle swapgs nicely when we
* don't have a stack we can rely on (such as a user space
* stack). So we either find a way around these or just fault
* and emulate if a guest tries to call swapgs directly.
*
* Either way, this is a good way to document that we don't
* have a reliable stack. x86_64 only.
*/
#define SWAPGS_UNSAFE_STACK swapgs
#define PARAVIRT_ADJUST_EXCEPTION_FRAME /* */
#define INTERRUPT_RETURN iretq
#define USERGS_SYSRET64 \
swapgs; \
sysretq;
#define USERGS_SYSRET32 \
swapgs; \
sysretl
#define ENABLE_INTERRUPTS_SYSEXIT32 \
swapgs; \
sti; \
sysexit
#else
#define INTERRUPT_RETURN iret
#define ENABLE_INTERRUPTS_SYSEXIT sti; sysexit
#define GET_CR0_INTO_EAX movl %cr0, %eax
#endif
#endif /* __ASSEMBLY__ */
#endif /* CONFIG_PARAVIRT */
#ifndef __ASSEMBLY__
#define raw_local_save_flags(flags) \
do { (flags) = __raw_local_save_flags(); } while (0)
#define raw_local_irq_save(flags) \
do { (flags) = __raw_local_irq_save(); } while (0)
static inline int raw_irqs_disabled_flags(unsigned long flags)
{
return !(flags & X86_EFLAGS_IF);
}
static inline int raw_irqs_disabled(void)
{
unsigned long flags = __raw_local_save_flags();
return raw_irqs_disabled_flags(flags);
}
/*
* makes the traced hardirq state match with the machine state
*
* should be a rarely used function, only in places where its
* otherwise impossible to know the irq state, like in traps.
*/
static inline void trace_hardirqs_fixup_flags(unsigned long flags)
{
if (raw_irqs_disabled_flags(flags))
trace_hardirqs_off();
else
trace_hardirqs_on();
}
static inline void trace_hardirqs_fixup(void)
{
unsigned long flags = __raw_local_save_flags();
trace_hardirqs_fixup_flags(flags);
}
#else
#ifdef CONFIG_X86_64
#define ARCH_LOCKDEP_SYS_EXIT call lockdep_sys_exit_thunk
#define ARCH_LOCKDEP_SYS_EXIT_IRQ \
TRACE_IRQS_ON; \
sti; \
SAVE_REST; \
LOCKDEP_SYS_EXIT; \
RESTORE_REST; \
cli; \
TRACE_IRQS_OFF;
#else
#define ARCH_LOCKDEP_SYS_EXIT \
pushl %eax; \
pushl %ecx; \
pushl %edx; \
call lockdep_sys_exit; \
popl %edx; \
popl %ecx; \
popl %eax;
#define ARCH_LOCKDEP_SYS_EXIT_IRQ
#endif
#ifdef CONFIG_TRACE_IRQFLAGS
ftrace: trace irq disabled critical timings This patch adds latency tracing for critical timings (how long interrupts are disabled for). "irqsoff" is added to /debugfs/tracing/available_tracers Note: tracing_max_latency also holds the max latency for irqsoff (in usecs). (default to large number so one must start latency tracing) tracing_thresh threshold (in usecs) to always print out if irqs off is detected to be longer than stated here. If irq_thresh is non-zero, then max_irq_latency is ignored. Here's an example of a trace with ftrace_enabled = 0 ======= preemption latency trace v1.1.5 on 2.6.24-rc7 Signed-off-by: Ingo Molnar <mingo@elte.hu> -------------------------------------------------------------------- latency: 100 us, #3/3, CPU#1 | (M:rt VP:0, KP:0, SP:0 HP:0 #P:2) ----------------- | task: swapper-0 (uid:0 nice:0 policy:0 rt_prio:0) ----------------- => started at: _spin_lock_irqsave+0x2a/0xb7 => ended at: _spin_unlock_irqrestore+0x32/0x5f _------=> CPU# / _-----=> irqs-off | / _----=> need-resched || / _---=> hardirq/softirq ||| / _--=> preempt-depth |||| / ||||| delay cmd pid ||||| time | caller \ / ||||| \ | / swapper-0 1d.s3 0us+: _spin_lock_irqsave+0x2a/0xb7 (e1000_update_stats+0x47/0x64c [e1000]) swapper-0 1d.s3 100us : _spin_unlock_irqrestore+0x32/0x5f (e1000_update_stats+0x641/0x64c [e1000]) swapper-0 1d.s3 100us : trace_hardirqs_on_caller+0x75/0x89 (_spin_unlock_irqrestore+0x32/0x5f) vim:ft=help ======= And this is a trace with ftrace_enabled == 1 ======= preemption latency trace v1.1.5 on 2.6.24-rc7 -------------------------------------------------------------------- latency: 102 us, #12/12, CPU#1 | (M:rt VP:0, KP:0, SP:0 HP:0 #P:2) ----------------- | task: swapper-0 (uid:0 nice:0 policy:0 rt_prio:0) ----------------- => started at: _spin_lock_irqsave+0x2a/0xb7 => ended at: _spin_unlock_irqrestore+0x32/0x5f _------=> CPU# / _-----=> irqs-off | / _----=> need-resched || / _---=> hardirq/softirq ||| / _--=> preempt-depth |||| / ||||| delay cmd pid ||||| time | caller \ / ||||| \ | / swapper-0 1dNs3 0us+: _spin_lock_irqsave+0x2a/0xb7 (e1000_update_stats+0x47/0x64c [e1000]) swapper-0 1dNs3 46us : e1000_read_phy_reg+0x16/0x225 [e1000] (e1000_update_stats+0x5e2/0x64c [e1000]) swapper-0 1dNs3 46us : e1000_swfw_sync_acquire+0x10/0x99 [e1000] (e1000_read_phy_reg+0x49/0x225 [e1000]) swapper-0 1dNs3 46us : e1000_get_hw_eeprom_semaphore+0x12/0xa6 [e1000] (e1000_swfw_sync_acquire+0x36/0x99 [e1000]) swapper-0 1dNs3 47us : __const_udelay+0x9/0x47 (e1000_read_phy_reg+0x116/0x225 [e1000]) swapper-0 1dNs3 47us+: __delay+0x9/0x50 (__const_udelay+0x45/0x47) swapper-0 1dNs3 97us : preempt_schedule+0xc/0x84 (__delay+0x4e/0x50) swapper-0 1dNs3 98us : e1000_swfw_sync_release+0xc/0x55 [e1000] (e1000_read_phy_reg+0x211/0x225 [e1000]) swapper-0 1dNs3 99us+: e1000_put_hw_eeprom_semaphore+0x9/0x35 [e1000] (e1000_swfw_sync_release+0x50/0x55 [e1000]) swapper-0 1dNs3 101us : _spin_unlock_irqrestore+0xe/0x5f (e1000_update_stats+0x641/0x64c [e1000]) swapper-0 1dNs3 102us : _spin_unlock_irqrestore+0x32/0x5f (e1000_update_stats+0x641/0x64c [e1000]) swapper-0 1dNs3 102us : trace_hardirqs_on_caller+0x75/0x89 (_spin_unlock_irqrestore+0x32/0x5f) vim:ft=help ======= Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-12 19:20:42 +00:00
# define TRACE_IRQS_ON call trace_hardirqs_on_thunk;
# define TRACE_IRQS_OFF call trace_hardirqs_off_thunk;
#else
# define TRACE_IRQS_ON
# define TRACE_IRQS_OFF
#endif
#ifdef CONFIG_DEBUG_LOCK_ALLOC
# define LOCKDEP_SYS_EXIT ARCH_LOCKDEP_SYS_EXIT
# define LOCKDEP_SYS_EXIT_IRQ ARCH_LOCKDEP_SYS_EXIT_IRQ
# else
# define LOCKDEP_SYS_EXIT
# define LOCKDEP_SYS_EXIT_IRQ
# endif
#endif /* __ASSEMBLY__ */
#endif