debuggers.hg

changeset 18942:f4c1a347311b

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x86: unify local_irq_XXX()

This also removes an inconsistency in that x86-64's __save_flags() had
a memory clobber, while x86_32's didn't.

It further adds type checking since blindly using {pop,push}{l,q} on a
memory operand of unknown size bares the risk of corrupting other
data.

Finally, it eliminates the redundant (with local_irq_restore())
__restore_flags() macro and renames __save_flags() to
local_save_flags(), making the naming consistent with Linux (again?).

Signed-off-by: Jan Beulich <jbeulich@novell.com>
author Keir Fraser <keir.fraser@citrix.com>
date Thu Dec 11 11:36:00 2008 +0000 (2008-12-11)
parents 68555b9a7d98
children c15244125a69
files xen/include/asm-x86/system.h xen/include/asm-x86/x86_32/system.h xen/include/asm-x86/x86_64/system.h
line diff
     1.1 --- a/xen/include/asm-x86/system.h	Thu Dec 11 11:32:39 2008 +0000
     1.2 +++ b/xen/include/asm-x86/system.h	Thu Dec 11 11:36:00 2008 +0000
     1.3 @@ -1,8 +1,7 @@
     1.4  #ifndef __ASM_SYSTEM_H
     1.5  #define __ASM_SYSTEM_H
     1.6  
     1.7 -#include <xen/config.h>
     1.8 -#include <xen/types.h>
     1.9 +#include <xen/lib.h>
    1.10  #include <asm/bitops.h>
    1.11  
    1.12  #define read_segment_register(name)                             \
    1.13 @@ -171,10 +170,27 @@ static always_inline unsigned long __cmp
    1.14  /* used when interrupts are already enabled or to shutdown the processor */
    1.15  #define halt()          asm volatile ( "hlt" : : : "memory" )
    1.16  
    1.17 +#define local_save_flags(x)                                      \
    1.18 +({                                                               \
    1.19 +    BUILD_BUG_ON(sizeof(x) != sizeof(long));                     \
    1.20 +    asm volatile ( "pushf" __OS " ; pop" __OS " %0" : "=g" (x)); \
    1.21 +})
    1.22 +#define local_irq_save(x)                                        \
    1.23 +({                                                               \
    1.24 +    local_save_flags(x);                                         \
    1.25 +    local_irq_disable();                                         \
    1.26 +})
    1.27 +#define local_irq_restore(x)                                     \
    1.28 +({                                                               \
    1.29 +    BUILD_BUG_ON(sizeof(x) != sizeof(long));                     \
    1.30 +    asm volatile ( "push" __OS " %0 ; popf" __OS                 \
    1.31 +                   : : "g" (x) : "memory", "cc" );               \
    1.32 +})
    1.33 +
    1.34  static inline int local_irq_is_enabled(void)
    1.35  {
    1.36      unsigned long flags;
    1.37 -    __save_flags(flags);
    1.38 +    local_save_flags(flags);
    1.39      return !!(flags & (1<<9)); /* EFLAGS_IF */
    1.40  }
    1.41  

     2.1 --- a/xen/include/asm-x86/x86_32/system.h	Thu Dec 11 11:32:39 2008 +0000
     2.2 +++ b/xen/include/asm-x86/x86_32/system.h	Thu Dec 11 11:36:00 2008 +0000
     2.3 @@ -101,14 +101,4 @@ static inline void atomic_write64(uint64
     2.4  #define mb()                    \
     2.5      asm volatile ( "lock; addl $0,0(%%esp)" : : : "memory" )
     2.6  
     2.7 -#define __save_flags(x)         \
     2.8 -    asm volatile ( "pushfl ; popl %0" : "=g" (x) : )
     2.9 -#define __restore_flags(x)      \
    2.10 -    asm volatile ( "pushl %0 ; popfl" : : "g" (x) : "memory", "cc" )
    2.11 -
    2.12 -#define local_irq_save(x)       \
    2.13 -    asm volatile ( "pushfl ; popl %0 ; cli" : "=g" (x) : : "memory" )
    2.14 -#define local_irq_restore(x)    \
    2.15 -    __restore_flags(x)
    2.16 -
    2.17  #endif /* __X86_32_SYSTEM_H__ */

     3.1 --- a/xen/include/asm-x86/x86_64/system.h	Thu Dec 11 11:32:39 2008 +0000
     3.2 +++ b/xen/include/asm-x86/x86_64/system.h	Thu Dec 11 11:36:00 2008 +0000
     3.3 @@ -55,14 +55,4 @@ static inline void atomic_write64(uint64
     3.4  #define mb()                    \
     3.5      asm volatile ( "mfence" : : : "memory" )
     3.6  
     3.7 -#define __save_flags(x)         \
     3.8 -    asm volatile ( "pushfq ; popq %q0" : "=g" (x) : :"memory" )
     3.9 -#define __restore_flags(x)      \
    3.10 -    asm volatile ( "pushq %0 ; popfq" : : "g" (x) : "memory", "cc" )
    3.11 -
    3.12 -#define local_irq_save(x)       \
    3.13 -    asm volatile ( "pushfq ; popq %0 ; cli" : "=g" (x) : : "memory" )
    3.14 -#define local_irq_restore(x)    \
    3.15 -    __restore_flags(x)
    3.16 -
    3.17  #endif /* __X86_64_SYSTEM_H__ */