Messages in this thread Patch in this message | | | Subject | [PATCH] ppc64: fix memcpy_to/from_io | From | Benjamin Herrenschmidt <> | Date | Fri, 30 Jul 2004 14:22:19 +1000 |
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Hi !
The ppc64 implementation of memcpy_to/from_io was bogus (used memcpy which uses cache hints and thus is broken on non cacheable IO space).
This re-implements them with some simple/gross C code doing 32 bits accesses when aligned and bytes accesses when not.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
===== include/asm-ppc64/eeh.h 1.12 vs ? (writable without lock!) ===== --- 1.12/include/asm-ppc64/eeh.h 2004-07-02 15:23:45 +10:00 +++ ?/include/asm-ppc64/eeh.h 2004-07-30 14:19:48 +10:00 @@ -180,26 +180,95 @@ out_be64(vaddr, val); } +#define EEH_CHECK_ALIGN(v,a) \ + ((((unsigned long)(v)) & ((a) - 1)) == 0) + static inline void eeh_memset_io(void *addr, int c, unsigned long n) { void *vaddr = (void *)IO_TOKEN_TO_ADDR(addr); - memset(vaddr, c, n); + u32 lc = c; + lc |= lc << 8; + lc |= lc << 16; + + while(n && !EEH_CHECK_ALIGN(vaddr, 4)) { + *((volatile u8 *)vaddr) = c; + vaddr = (void *)((unsigned long)vaddr + 1); + n--; + } + while(n >= 4) { + *((volatile u32 *)vaddr) = lc; + vaddr = (void *)((unsigned long)vaddr + 4); + n -= 4; + } + while(n) { + *((volatile u8 *)vaddr) = c; + vaddr = (void *)((unsigned long)vaddr + 1); + n--; + } + __asm__ __volatile__ ("sync" : : : "memory"); } static inline void eeh_memcpy_fromio(void *dest, void *src, unsigned long n) { void *vsrc = (void *)IO_TOKEN_TO_ADDR(src); - memcpy(dest, vsrc, n); + void *vsrcsave = vsrc, *destsave = dest, *srcsave = src; + unsigned long nsave = n; + + while(n && (!EEH_CHECK_ALIGN(vsrc, 4) || !EEH_CHECK_ALIGN(dest, 4))) { + *((u8 *)dest) = *((volatile u8 *)vsrc); + __asm__ __volatile__ ("eieio" : : : "memory"); + vsrc = (void *)((unsigned long)vsrc + 1); + dest = (void *)((unsigned long)dest + 1); + n--; + } + while(n > 4) { + *((u32 *)dest) = *((volatile u32 *)vsrc); + __asm__ __volatile__ ("eieio" : : : "memory"); + vsrc = (void *)((unsigned long)vsrc + 4); + dest = (void *)((unsigned long)dest + 4); + n -= 4; + } + while(n) { + *((u8 *)dest) = *((volatile u8 *)vsrc); + __asm__ __volatile__ ("eieio" : : : "memory"); + vsrc = (void *)((unsigned long)vsrc + 1); + dest = (void *)((unsigned long)dest + 1); + n--; + } + __asm__ __volatile__ ("sync" : : : "memory"); + /* Look for ffff's here at dest[n]. Assume that at least 4 bytes * were copied. Check all four bytes. */ - if ((n >= 4) && - (EEH_POSSIBLE_ERROR(src, vsrc, (*((u32 *) dest+n-4)), u32))) { - eeh_check_failure(src, (*((u32 *) dest+n-4))); + if ((nsave >= 4) && + (EEH_POSSIBLE_ERROR(srcsave, vsrcsave, (*((u32 *) destsave+nsave-4)), + u32))) { + eeh_check_failure(srcsave, (*((u32 *) destsave+nsave-4))); } } static inline void eeh_memcpy_toio(void *dest, void *src, unsigned long n) { void *vdest = (void *)IO_TOKEN_TO_ADDR(dest); - memcpy(vdest, src, n); + + while(n && (!EEH_CHECK_ALIGN(vdest, 4) || !EEH_CHECK_ALIGN(src, 4))) { + *((volatile u8 *)vdest) = *((u8 *)src); + src = (void *)((unsigned long)src + 1); + vdest = (void *)((unsigned long)vdest + 1); + n--; + } + while(n > 4) { + *((volatile u32 *)vdest) = *((volatile u32 *)src); + src = (void *)((unsigned long)src + 4); + vdest = (void *)((unsigned long)vdest + 4); + n-=4; + } + while(n) { + *((volatile u8 *)vdest) = *((u8 *)src); + src = (void *)((unsigned long)src + 1); + vdest = (void *)((unsigned long)vdest + 1); + n--; + } + __asm__ __volatile__ ("sync" : : : "memory"); } + +#undef EEH_CHECK_ALIGN #define MAX_ISA_PORT 0x10000 extern unsigned long io_page_mask;
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