[PATCH] ppc64: fix memcpy_to/from_io

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>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/include/asm-ppc64/eeh.h b/include/asm-ppc64/eeh.h
index d5e44bf36c7b64b5ebc23c1d993622099a3d8457..a877ce9aa63a198b3738dee97227be1bc7f15c4f 100644 (file)
--- a/include/asm-ppc64/eeh.h
+++ b/include/asm-ppc64/eeh.h
@@ -180,27 +180,96 @@ static inline void eeh_raw_writeq(u64 val, void *addr) {
        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;
 #define _IO_IS_VALID(port) ((port) >= MAX_ISA_PORT || (1 << (port>>PAGE_SHIFT)) & io_page_mask)