/* unaligned.h: unaligned access handler * * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #ifndef _ASM_UNALIGNED_H #define _ASM_UNALIGNED_H #include <linux/config.h> /* * Unaligned accesses on uClinux can't be performed in a fault handler - the * CPU detects them as imprecise exceptions making this impossible. * * With the FR451, however, they are precise, and so we used to fix them up in * the memory access fault handler. However, instruction bundling make this * impractical. So, now we fall back to using memcpy. */ #ifdef CONFIG_MMU /* * The asm statement in the macros below is a way to get GCC to copy a * value from one variable to another without having any clue it's * actually doing so, so that it won't have any idea that the values * in the two variables are related. */ #define get_unaligned(ptr) ({ \ typeof((*(ptr))) __x; \ void *__ptrcopy; \ asm("" : "=r" (__ptrcopy) : "0" (ptr)); \ memcpy(&__x, __ptrcopy, sizeof(*(ptr))); \ __x; \ }) #define put_unaligned(val, ptr) ({ \ typeof((*(ptr))) __x = (val); \ void *__ptrcopy; \ asm("" : "=r" (__ptrcopy) : "0" (ptr)); \ memcpy(__ptrcopy, &__x, sizeof(*(ptr))); \ }) extern int handle_misalignment(unsigned long esr0, unsigned long ear0, unsigned long epcr0); #else #define get_unaligned(ptr) \ ({ \ typeof(*(ptr)) x; \ const char *__p = (const char *) (ptr); \ \ switch (sizeof(x)) { \ case 1: \ x = *(ptr); \ break; \ case 2: \ { \ uint8_t a; \ asm(" ldub%I2 %M2,%0 \n" \ " ldub%I3.p %M3,%1 \n" \ " slli %0,#8,%0 \n" \ " or %0,%1,%0 \n" \ : "=&r"(x), "=&r"(a) \ : "m"(__p[0]), "m"(__p[1]) \ ); \ break; \ } \ \ case 4: \ { \ uint8_t a; \ asm(" ldub%I2 %M2,%0 \n" \ " ldub%I3.p %M3,%1 \n" \ " slli %0,#8,%0 \n" \ " or %0,%1,%0 \n" \ " ldub%I4.p %M4,%1 \n" \ " slli %0,#8,%0 \n" \ " or %0,%1,%0 \n" \ " ldub%I5.p %M5,%1 \n" \ " slli %0,#8,%0 \n" \ " or %0,%1,%0 \n" \ : "=&r"(x), "=&r"(a) \ : "m"(__p[0]), "m"(__p[1]), "m"(__p[2]), "m"(__p[3]) \ ); \ break; \ } \ \ case 8: \ { \ union { uint64_t x; u32 y[2]; } z; \ uint8_t a; \ asm(" ldub%I3 %M3,%0 \n" \ " ldub%I4.p %M4,%2 \n" \ " slli %0,#8,%0 \n" \ " or %0,%2,%0 \n" \ " ldub%I5.p %M5,%2 \n" \ " slli %0,#8,%0 \n" \ " or %0,%2,%0 \n" \ " ldub%I6.p %M6,%2 \n" \ " slli %0,#8,%0 \n" \ " or %0,%2,%0 \n" \ " ldub%I7 %M7,%1 \n" \ " ldub%I8.p %M8,%2 \n" \ " slli %1,#8,%1 \n" \ " or %1,%2,%1 \n" \ " ldub%I9.p %M9,%2 \n" \ " slli %1,#8,%1 \n" \ " or %1,%2,%1 \n" \ " ldub%I10.p %M10,%2 \n" \ " slli %1,#8,%1 \n" \ " or %1,%2,%1 \n" \ : "=&r"(z.y[0]), "=&r"(z.y[1]), "=&r"(a) \ : "m"(__p[0]), "m"(__p[1]), "m"(__p[2]), "m"(__p[3]), \ "m"(__p[4]), "m"(__p[5]), "m"(__p[6]), "m"(__p[7]) \ ); \ x = z.x; \ break; \ } \ \ default: \ x = 0; \ BUG(); \ break; \ } \ \ x; \ }) #define put_unaligned(val, ptr) \ do { \ char *__p = (char *) (ptr); \ int x; \ \ switch (sizeof(*ptr)) { \ case 2: \ { \ asm(" stb%I1.p %0,%M1 \n" \ " srli %0,#8,%0 \n" \ " stb%I2 %0,%M2 \n" \ : "=r"(x), "=m"(__p[1]), "=m"(__p[0]) \ : "0"(val) \ ); \ break; \ } \ \ case 4: \ { \ asm(" stb%I1.p %0,%M1 \n" \ " srli %0,#8,%0 \n" \ " stb%I2.p %0,%M2 \n" \ " srli %0,#8,%0 \n" \ " stb%I3.p %0,%M3 \n" \ " srli %0,#8,%0 \n" \ " stb%I4 %0,%M4 \n" \ : "=r"(x), "=m"(__p[3]), "=m"(__p[2]), "=m"(__p[1]), "=m"(__p[0]) \ : "0"(val) \ ); \ break; \ } \ \ case 8: \ { \ uint32_t __high, __low; \ __high = (uint64_t)val >> 32; \ __low = val & 0xffffffff; \ asm(" stb%I2.p %0,%M2 \n" \ " srli %0,#8,%0 \n" \ " stb%I3.p %0,%M3 \n" \ " srli %0,#8,%0 \n" \ " stb%I4.p %0,%M4 \n" \ " srli %0,#8,%0 \n" \ " stb%I5.p %0,%M5 \n" \ " srli %0,#8,%0 \n" \ " stb%I6.p %1,%M6 \n" \ " srli %1,#8,%1 \n" \ " stb%I7.p %1,%M7 \n" \ " srli %1,#8,%1 \n" \ " stb%I8.p %1,%M8 \n" \ " srli %1,#8,%1 \n" \ " stb%I9 %1,%M9 \n" \ : "=&r"(__low), "=&r"(__high), "=m"(__p[7]), "=m"(__p[6]), \ "=m"(__p[5]), "=m"(__p[4]), "=m"(__p[3]), "=m"(__p[2]), \ "=m"(__p[1]), "=m"(__p[0]) \ : "0"(__low), "1"(__high) \ ); \ break; \ } \ \ default: \ *(ptr) = (val); \ break; \ } \ } while(0) #endif #endif