diff options
author | David Woodhouse <dwmw2@infradead.org> | 2007-10-13 14:58:23 +0100 |
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committer | David Woodhouse <dwmw2@infradead.org> | 2007-10-13 14:58:23 +0100 |
commit | ebf8889bd1fe3615991ff4494635d237280652a2 (patch) | |
tree | 10fb735717122bbb86474339eac07f26e7ccdf40 /include/asm-x86/processor-cyrix.h | |
parent | b160292cc216a50fd0cd386b0bda2cd48352c73b (diff) | |
parent | 752097cec53eea111d087c545179b421e2bde98a (diff) |
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
Diffstat (limited to 'include/asm-x86/processor-cyrix.h')
-rw-r--r-- | include/asm-x86/processor-cyrix.h | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/include/asm-x86/processor-cyrix.h b/include/asm-x86/processor-cyrix.h new file mode 100644 index 000000000000..97568ada1f97 --- /dev/null +++ b/include/asm-x86/processor-cyrix.h @@ -0,0 +1,30 @@ +/* + * NSC/Cyrix CPU indexed register access. Must be inlined instead of + * macros to ensure correct access ordering + * Access order is always 0x22 (=offset), 0x23 (=value) + * + * When using the old macros a line like + * setCx86(CX86_CCR2, getCx86(CX86_CCR2) | 0x88); + * gets expanded to: + * do { + * outb((CX86_CCR2), 0x22); + * outb((({ + * outb((CX86_CCR2), 0x22); + * inb(0x23); + * }) | 0x88), 0x23); + * } while (0); + * + * which in fact violates the access order (= 0x22, 0x22, 0x23, 0x23). + */ + +static inline u8 getCx86(u8 reg) +{ + outb(reg, 0x22); + return inb(0x23); +} + +static inline void setCx86(u8 reg, u8 data) +{ + outb(reg, 0x22); + outb(data, 0x23); +} |