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| author | Jeremy Fitzhardinge <jeremy@goop.org> | 2006-12-07 02:14:02 +0100 |
|---|---|---|
| committer | Andi Kleen <andi@basil.nowhere.org> | 2006-12-07 02:14:02 +0100 |
| commit | 9ca36101a8d74704d78f10910f89d62de96f9dc8 (patch) | |
| tree | 358086c902c021f9316968062dc1b1165cf5f897 /include/asm-i386 | |
| parent | eb5b7b9d86f46b45ba1f986302fdf7df84fb8297 (diff) | |
| download | linux-9ca36101a8d74704d78f10910f89d62de96f9dc8.tar.bz2 | |
[PATCH] i386: Basic definitions for i386-pda
This patch has the basic definitions of struct i386_pda, and the segment
selector in the GDT.
asm-i386/pda.h is more or less a direct copy of asm-x86_64/pda.h. The most
interesting difference is the use of _proxy_pda, which is used to give gcc a
model for the actual memory operations on the real pda structure. No actual
reference is ever made to _proxy_pda, so it is never defined.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Chuck Ebbert <76306.1226@compuserve.com>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Jan Beulich <jbeulich@novell.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Diffstat (limited to 'include/asm-i386')
| -rw-r--r-- | include/asm-i386/pda.h | 95 | ||||
| -rw-r--r-- | include/asm-i386/segment.h | 5 |
2 files changed, 99 insertions, 1 deletions
diff --git a/include/asm-i386/pda.h b/include/asm-i386/pda.h new file mode 100644 index 000000000000..4c39ccb1305c --- /dev/null +++ b/include/asm-i386/pda.h @@ -0,0 +1,95 @@ +/* + Per-processor Data Areas + Jeremy Fitzhardinge <jeremy@goop.org> 2006 + Based on asm-x86_64/pda.h by Andi Kleen. + */ +#ifndef _I386_PDA_H +#define _I386_PDA_H + +#include <linux/stddef.h> + +struct i386_pda +{ + struct i386_pda *_pda; /* pointer to self */ +}; + +extern struct i386_pda *_cpu_pda[]; + +#define cpu_pda(i) (_cpu_pda[i]) + +#define pda_offset(field) offsetof(struct i386_pda, field) + +extern void __bad_pda_field(void); + +/* This variable is never instantiated. It is only used as a stand-in + for the real per-cpu PDA memory, so that gcc can understand what + memory operations the inline asms() below are performing. This + eliminates the need to make the asms volatile or have memory + clobbers, so gcc can readily analyse them. */ +extern struct i386_pda _proxy_pda; + +#define pda_to_op(op,field,val) \ + do { \ + typedef typeof(_proxy_pda.field) T__; \ + if (0) { T__ tmp__; tmp__ = (val); } \ + switch (sizeof(_proxy_pda.field)) { \ + case 1: \ + asm(op "b %1,%%gs:%c2" \ + : "+m" (_proxy_pda.field) \ + :"ri" ((T__)val), \ + "i"(pda_offset(field))); \ + break; \ + case 2: \ + asm(op "w %1,%%gs:%c2" \ + : "+m" (_proxy_pda.field) \ + :"ri" ((T__)val), \ + "i"(pda_offset(field))); \ + break; \ + case 4: \ + asm(op "l %1,%%gs:%c2" \ + : "+m" (_proxy_pda.field) \ + :"ri" ((T__)val), \ + "i"(pda_offset(field))); \ + break; \ + default: __bad_pda_field(); \ + } \ + } while (0) + +#define pda_from_op(op,field) \ + ({ \ + typeof(_proxy_pda.field) ret__; \ + switch (sizeof(_proxy_pda.field)) { \ + case 1: \ + asm(op "b %%gs:%c1,%0" \ + : "=r" (ret__) \ + : "i" (pda_offset(field)), \ + "m" (_proxy_pda.field)); \ + break; \ + case 2: \ + asm(op "w %%gs:%c1,%0" \ + : "=r" (ret__) \ + : "i" (pda_offset(field)), \ + "m" (_proxy_pda.field)); \ + break; \ + case 4: \ + asm(op "l %%gs:%c1,%0" \ + : "=r" (ret__) \ + : "i" (pda_offset(field)), \ + "m" (_proxy_pda.field)); \ + break; \ + default: __bad_pda_field(); \ + } \ + ret__; }) + +/* Return a pointer to a pda field */ +#define pda_addr(field) \ + ((typeof(_proxy_pda.field) *)((unsigned char *)read_pda(_pda) + \ + pda_offset(field))) + +#define read_pda(field) pda_from_op("mov",field) +#define write_pda(field,val) pda_to_op("mov",field,val) +#define add_pda(field,val) pda_to_op("add",field,val) +#define sub_pda(field,val) pda_to_op("sub",field,val) +#define or_pda(field,val) pda_to_op("or",field,val) + +#endif /* _I386_PDA_H */ diff --git a/include/asm-i386/segment.h b/include/asm-i386/segment.h index b7ab59685ba7..5bdda79b6b53 100644 --- a/include/asm-i386/segment.h +++ b/include/asm-i386/segment.h @@ -39,7 +39,7 @@ * 25 - APM BIOS support * * 26 - ESPFIX small SS - * 27 - unused + * 27 - PDA [ per-cpu private data area ] * 28 - unused * 29 - unused * 30 - unused @@ -74,6 +74,9 @@ #define GDT_ENTRY_ESPFIX_SS (GDT_ENTRY_KERNEL_BASE + 14) #define __ESPFIX_SS (GDT_ENTRY_ESPFIX_SS * 8) +#define GDT_ENTRY_PDA (GDT_ENTRY_KERNEL_BASE + 15) +#define __KERNEL_PDA (GDT_ENTRY_PDA * 8) + #define GDT_ENTRY_DOUBLEFAULT_TSS 31 /* |