aha/include/asm-x86/processor-cyrix.h
Thomas Gleixner 96a388de5d i386/x86_64: move headers to include/asm-x86
Move the headers to include/asm-x86 and fixup the
header install make rules

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-11 11:20:03 +02:00

30 lines
681 B
C

/*
* 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);
}