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Diffstat (limited to 'kernel/arch/powerpc/kernel/align.c')
| -rw-r--r-- | kernel/arch/powerpc/kernel/align.c | 1042 |
1 files changed, 1042 insertions, 0 deletions
diff --git a/kernel/arch/powerpc/kernel/align.c b/kernel/arch/powerpc/kernel/align.c new file mode 100644 index 000000000..86150fbb4 --- /dev/null +++ b/kernel/arch/powerpc/kernel/align.c @@ -0,0 +1,1042 @@ +/* align.c - handle alignment exceptions for the Power PC. + * + * Copyright (c) 1996 Paul Mackerras <paulus@cs.anu.edu.au> + * Copyright (c) 1998-1999 TiVo, Inc. + * PowerPC 403GCX modifications. + * Copyright (c) 1999 Grant Erickson <grant@lcse.umn.edu> + * PowerPC 403GCX/405GP modifications. + * Copyright (c) 2001-2002 PPC64 team, IBM Corp + * 64-bit and Power4 support + * Copyright (c) 2005 Benjamin Herrenschmidt, IBM Corp + * <benh@kernel.crashing.org> + * Merge ppc32 and ppc64 implementations + * + * 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. + */ + +#include <linux/kernel.h> +#include <linux/mm.h> +#include <asm/processor.h> +#include <asm/uaccess.h> +#include <asm/cache.h> +#include <asm/cputable.h> +#include <asm/emulated_ops.h> +#include <asm/switch_to.h> +#include <asm/disassemble.h> + +struct aligninfo { + unsigned char len; + unsigned char flags; +}; + + +#define INVALID { 0, 0 } + +/* Bits in the flags field */ +#define LD 0 /* load */ +#define ST 1 /* store */ +#define SE 2 /* sign-extend value, or FP ld/st as word */ +#define F 4 /* to/from fp regs */ +#define U 8 /* update index register */ +#define M 0x10 /* multiple load/store */ +#define SW 0x20 /* byte swap */ +#define S 0x40 /* single-precision fp or... */ +#define SX 0x40 /* ... byte count in XER */ +#define HARD 0x80 /* string, stwcx. */ +#define E4 0x40 /* SPE endianness is word */ +#define E8 0x80 /* SPE endianness is double word */ +#define SPLT 0x80 /* VSX SPLAT load */ + +/* DSISR bits reported for a DCBZ instruction: */ +#define DCBZ 0x5f /* 8xx/82xx dcbz faults when cache not enabled */ + +/* + * The PowerPC stores certain bits of the instruction that caused the + * alignment exception in the DSISR register. This array maps those + * bits to information about the operand length and what the + * instruction would do. + */ +static struct aligninfo aligninfo[128] = { + { 4, LD }, /* 00 0 0000: lwz / lwarx */ + INVALID, /* 00 0 0001 */ + { 4, ST }, /* 00 0 0010: stw */ + INVALID, /* 00 0 0011 */ + { 2, LD }, /* 00 0 0100: lhz */ + { 2, LD+SE }, /* 00 0 0101: lha */ + { 2, ST }, /* 00 0 0110: sth */ + { 4, LD+M }, /* 00 0 0111: lmw */ + { 4, LD+F+S }, /* 00 0 1000: lfs */ + { 8, LD+F }, /* 00 0 1001: lfd */ + { 4, ST+F+S }, /* 00 0 1010: stfs */ + { 8, ST+F }, /* 00 0 1011: stfd */ + { 16, LD }, /* 00 0 1100: lq */ + { 8, LD }, /* 00 0 1101: ld/ldu/lwa */ + INVALID, /* 00 0 1110 */ + { 8, ST }, /* 00 0 1111: std/stdu */ + { 4, LD+U }, /* 00 1 0000: lwzu */ + INVALID, /* 00 1 0001 */ + { 4, ST+U }, /* 00 1 0010: stwu */ + INVALID, /* 00 1 0011 */ + { 2, LD+U }, /* 00 1 0100: lhzu */ + { 2, LD+SE+U }, /* 00 1 0101: lhau */ + { 2, ST+U }, /* 00 1 0110: sthu */ + { 4, ST+M }, /* 00 1 0111: stmw */ + { 4, LD+F+S+U }, /* 00 1 1000: lfsu */ + { 8, LD+F+U }, /* 00 1 1001: lfdu */ + { 4, ST+F+S+U }, /* 00 1 1010: stfsu */ + { 8, ST+F+U }, /* 00 1 1011: stfdu */ + { 16, LD+F }, /* 00 1 1100: lfdp */ + INVALID, /* 00 1 1101 */ + { 16, ST+F }, /* 00 1 1110: stfdp */ + INVALID, /* 00 1 1111 */ + { 8, LD }, /* 01 0 0000: ldx */ + INVALID, /* 01 0 0001 */ + { 8, ST }, /* 01 0 0010: stdx */ + INVALID, /* 01 0 0011 */ + INVALID, /* 01 0 0100 */ + { 4, LD+SE }, /* 01 0 0101: lwax */ + INVALID, /* 01 0 0110 */ + INVALID, /* 01 0 0111 */ + { 4, LD+M+HARD+SX }, /* 01 0 1000: lswx */ + { 4, LD+M+HARD }, /* 01 0 1001: lswi */ + { 4, ST+M+HARD+SX }, /* 01 0 1010: stswx */ + { 4, ST+M+HARD }, /* 01 0 1011: stswi */ + INVALID, /* 01 0 1100 */ + { 8, LD+U }, /* 01 0 1101: ldu */ + INVALID, /* 01 0 1110 */ + { 8, ST+U }, /* 01 0 1111: stdu */ + { 8, LD+U }, /* 01 1 0000: ldux */ + INVALID, /* 01 1 0001 */ + { 8, ST+U }, /* 01 1 0010: stdux */ + INVALID, /* 01 1 0011 */ + INVALID, /* 01 1 0100 */ + { 4, LD+SE+U }, /* 01 1 0101: lwaux */ + INVALID, /* 01 1 0110 */ + INVALID, /* 01 1 0111 */ + INVALID, /* 01 1 1000 */ + INVALID, /* 01 1 1001 */ + INVALID, /* 01 1 1010 */ + INVALID, /* 01 1 1011 */ + INVALID, /* 01 1 1100 */ + INVALID, /* 01 1 1101 */ + INVALID, /* 01 1 1110 */ + INVALID, /* 01 1 1111 */ + INVALID, /* 10 0 0000 */ + INVALID, /* 10 0 0001 */ + INVALID, /* 10 0 0010: stwcx. */ + INVALID, /* 10 0 0011 */ + INVALID, /* 10 0 0100 */ + INVALID, /* 10 0 0101 */ + INVALID, /* 10 0 0110 */ + INVALID, /* 10 0 0111 */ + { 4, LD+SW }, /* 10 0 1000: lwbrx */ + INVALID, /* 10 0 1001 */ + { 4, ST+SW }, /* 10 0 1010: stwbrx */ + INVALID, /* 10 0 1011 */ + { 2, LD+SW }, /* 10 0 1100: lhbrx */ + { 4, LD+SE }, /* 10 0 1101 lwa */ + { 2, ST+SW }, /* 10 0 1110: sthbrx */ + { 16, ST }, /* 10 0 1111: stq */ + INVALID, /* 10 1 0000 */ + INVALID, /* 10 1 0001 */ + INVALID, /* 10 1 0010 */ + INVALID, /* 10 1 0011 */ + INVALID, /* 10 1 0100 */ + INVALID, /* 10 1 0101 */ + INVALID, /* 10 1 0110 */ + INVALID, /* 10 1 0111 */ + INVALID, /* 10 1 1000 */ + INVALID, /* 10 1 1001 */ + INVALID, /* 10 1 1010 */ + INVALID, /* 10 1 1011 */ + INVALID, /* 10 1 1100 */ + INVALID, /* 10 1 1101 */ + INVALID, /* 10 1 1110 */ + { 0, ST+HARD }, /* 10 1 1111: dcbz */ + { 4, LD }, /* 11 0 0000: lwzx */ + INVALID, /* 11 0 0001 */ + { 4, ST }, /* 11 0 0010: stwx */ + INVALID, /* 11 0 0011 */ + { 2, LD }, /* 11 0 0100: lhzx */ + { 2, LD+SE }, /* 11 0 0101: lhax */ + { 2, ST }, /* 11 0 0110: sthx */ + INVALID, /* 11 0 0111 */ + { 4, LD+F+S }, /* 11 0 1000: lfsx */ + { 8, LD+F }, /* 11 0 1001: lfdx */ + { 4, ST+F+S }, /* 11 0 1010: stfsx */ + { 8, ST+F }, /* 11 0 1011: stfdx */ + { 16, LD+F }, /* 11 0 1100: lfdpx */ + { 4, LD+F+SE }, /* 11 0 1101: lfiwax */ + { 16, ST+F }, /* 11 0 1110: stfdpx */ + { 4, ST+F }, /* 11 0 1111: stfiwx */ + { 4, LD+U }, /* 11 1 0000: lwzux */ + INVALID, /* 11 1 0001 */ + { 4, ST+U }, /* 11 1 0010: stwux */ + INVALID, /* 11 1 0011 */ + { 2, LD+U }, /* 11 1 0100: lhzux */ + { 2, LD+SE+U }, /* 11 1 0101: lhaux */ + { 2, ST+U }, /* 11 1 0110: sthux */ + INVALID, /* 11 1 0111 */ + { 4, LD+F+S+U }, /* 11 1 1000: lfsux */ + { 8, LD+F+U }, /* 11 1 1001: lfdux */ + { 4, ST+F+S+U }, /* 11 1 1010: stfsux */ + { 8, ST+F+U }, /* 11 1 1011: stfdux */ + INVALID, /* 11 1 1100 */ + { 4, LD+F }, /* 11 1 1101: lfiwzx */ + INVALID, /* 11 1 1110 */ + INVALID, /* 11 1 1111 */ +}; + +/* + * The dcbz (data cache block zero) instruction + * gives an alignment fault if used on non-cacheable + * memory. We handle the fault mainly for the + * case when we are running with the cache disabled + * for debugging. + */ +static int emulate_dcbz(struct pt_regs *regs, unsigned char __user *addr) +{ + long __user *p; + int i, size; + +#ifdef __powerpc64__ + size = ppc64_caches.dline_size; +#else + size = L1_CACHE_BYTES; +#endif + p = (long __user *) (regs->dar & -size); + if (user_mode(regs) && !access_ok(VERIFY_WRITE, p, size)) + return -EFAULT; + for (i = 0; i < size / sizeof(long); ++i) + if (__put_user_inatomic(0, p+i)) + return -EFAULT; + return 1; +} + +/* + * Emulate load & store multiple instructions + * On 64-bit machines, these instructions only affect/use the + * bottom 4 bytes of each register, and the loads clear the + * top 4 bytes of the affected register. + */ +#ifdef __BIG_ENDIAN__ +#ifdef CONFIG_PPC64 +#define REG_BYTE(rp, i) *((u8 *)((rp) + ((i) >> 2)) + ((i) & 3) + 4) +#else +#define REG_BYTE(rp, i) *((u8 *)(rp) + (i)) +#endif +#endif + +#ifdef __LITTLE_ENDIAN__ +#define REG_BYTE(rp, i) (*(((u8 *)((rp) + ((i)>>2)) + ((i)&3)))) +#endif + +#define SWIZ_PTR(p) ((unsigned char __user *)((p) ^ swiz)) + +static int emulate_multiple(struct pt_regs *regs, unsigned char __user *addr, + unsigned int reg, unsigned int nb, + unsigned int flags, unsigned int instr, + unsigned long swiz) +{ + unsigned long *rptr; + unsigned int nb0, i, bswiz; + unsigned long p; + + /* + * We do not try to emulate 8 bytes multiple as they aren't really + * available in our operating environments and we don't try to + * emulate multiples operations in kernel land as they should never + * be used/generated there at least not on unaligned boundaries + */ + if (unlikely((nb > 4) || !user_mode(regs))) + return 0; + + /* lmw, stmw, lswi/x, stswi/x */ + nb0 = 0; + if (flags & HARD) { + if (flags & SX) { + nb = regs->xer & 127; + if (nb == 0) + return 1; + } else { + unsigned long pc = regs->nip ^ (swiz & 4); + + if (__get_user_inatomic(instr, + (unsigned int __user *)pc)) + return -EFAULT; + if (swiz == 0 && (flags & SW)) + instr = cpu_to_le32(instr); + nb = (instr >> 11) & 0x1f; + if (nb == 0) + nb = 32; + } + if (nb + reg * 4 > 128) { + nb0 = nb + reg * 4 - 128; + nb = 128 - reg * 4; + } +#ifdef __LITTLE_ENDIAN__ + /* + * String instructions are endian neutral but the code + * below is not. Force byte swapping on so that the + * effects of swizzling are undone in the load/store + * loops below. + */ + flags ^= SW; +#endif + } else { + /* lwm, stmw */ + nb = (32 - reg) * 4; + } + + if (!access_ok((flags & ST ? VERIFY_WRITE: VERIFY_READ), addr, nb+nb0)) + return -EFAULT; /* bad address */ + + rptr = ®s->gpr[reg]; + p = (unsigned long) addr; + bswiz = (flags & SW)? 3: 0; + + if (!(flags & ST)) { + /* + * This zeroes the top 4 bytes of the affected registers + * in 64-bit mode, and also zeroes out any remaining + * bytes of the last register for lsw*. + */ + memset(rptr, 0, ((nb + 3) / 4) * sizeof(unsigned long)); + if (nb0 > 0) + memset(®s->gpr[0], 0, + ((nb0 + 3) / 4) * sizeof(unsigned long)); + + for (i = 0; i < nb; ++i, ++p) + if (__get_user_inatomic(REG_BYTE(rptr, i ^ bswiz), + SWIZ_PTR(p))) + return -EFAULT; + if (nb0 > 0) { + rptr = ®s->gpr[0]; + addr += nb; + for (i = 0; i < nb0; ++i, ++p) + if (__get_user_inatomic(REG_BYTE(rptr, + i ^ bswiz), + SWIZ_PTR(p))) + return -EFAULT; + } + + } else { + for (i = 0; i < nb; ++i, ++p) + if (__put_user_inatomic(REG_BYTE(rptr, i ^ bswiz), + SWIZ_PTR(p))) + return -EFAULT; + if (nb0 > 0) { + rptr = ®s->gpr[0]; + addr += nb; + for (i = 0; i < nb0; ++i, ++p) + if (__put_user_inatomic(REG_BYTE(rptr, + i ^ bswiz), + SWIZ_PTR(p))) + return -EFAULT; + } + } + return 1; +} + +/* + * Emulate floating-point pair loads and stores. + * Only POWER6 has these instructions, and it does true little-endian, + * so we don't need the address swizzling. + */ +static int emulate_fp_pair(unsigned char __user *addr, unsigned int reg, + unsigned int flags) +{ + char *ptr0 = (char *) ¤t->thread.TS_FPR(reg); + char *ptr1 = (char *) ¤t->thread.TS_FPR(reg+1); + int i, ret, sw = 0; + + if (reg & 1) + return 0; /* invalid form: FRS/FRT must be even */ + if (flags & SW) + sw = 7; + ret = 0; + for (i = 0; i < 8; ++i) { + if (!(flags & ST)) { + ret |= __get_user(ptr0[i^sw], addr + i); + ret |= __get_user(ptr1[i^sw], addr + i + 8); + } else { + ret |= __put_user(ptr0[i^sw], addr + i); + ret |= __put_user(ptr1[i^sw], addr + i + 8); + } + } + if (ret) + return -EFAULT; + return 1; /* exception handled and fixed up */ +} + +#ifdef CONFIG_PPC64 +static int emulate_lq_stq(struct pt_regs *regs, unsigned char __user *addr, + unsigned int reg, unsigned int flags) +{ + char *ptr0 = (char *)®s->gpr[reg]; + char *ptr1 = (char *)®s->gpr[reg+1]; + int i, ret, sw = 0; + + if (reg & 1) + return 0; /* invalid form: GPR must be even */ + if (flags & SW) + sw = 7; + ret = 0; + for (i = 0; i < 8; ++i) { + if (!(flags & ST)) { + ret |= __get_user(ptr0[i^sw], addr + i); + ret |= __get_user(ptr1[i^sw], addr + i + 8); + } else { + ret |= __put_user(ptr0[i^sw], addr + i); + ret |= __put_user(ptr1[i^sw], addr + i + 8); + } + } + if (ret) + return -EFAULT; + return 1; /* exception handled and fixed up */ +} +#endif /* CONFIG_PPC64 */ + +#ifdef CONFIG_SPE + +static struct aligninfo spe_aligninfo[32] = { + { 8, LD+E8 }, /* 0 00 00: evldd[x] */ + { 8, LD+E4 }, /* 0 00 01: evldw[x] */ + { 8, LD }, /* 0 00 10: evldh[x] */ + INVALID, /* 0 00 11 */ + { 2, LD }, /* 0 01 00: evlhhesplat[x] */ + INVALID, /* 0 01 01 */ + { 2, LD }, /* 0 01 10: evlhhousplat[x] */ + { 2, LD+SE }, /* 0 01 11: evlhhossplat[x] */ + { 4, LD }, /* 0 10 00: evlwhe[x] */ + INVALID, /* 0 10 01 */ + { 4, LD }, /* 0 10 10: evlwhou[x] */ + { 4, LD+SE }, /* 0 10 11: evlwhos[x] */ + { 4, LD+E4 }, /* 0 11 00: evlwwsplat[x] */ + INVALID, /* 0 11 01 */ + { 4, LD }, /* 0 11 10: evlwhsplat[x] */ + INVALID, /* 0 11 11 */ + + { 8, ST+E8 }, /* 1 00 00: evstdd[x] */ + { 8, ST+E4 }, /* 1 00 01: evstdw[x] */ + { 8, ST }, /* 1 00 10: evstdh[x] */ + INVALID, /* 1 00 11 */ + INVALID, /* 1 01 00 */ + INVALID, /* 1 01 01 */ + INVALID, /* 1 01 10 */ + INVALID, /* 1 01 11 */ + { 4, ST }, /* 1 10 00: evstwhe[x] */ + INVALID, /* 1 10 01 */ + { 4, ST }, /* 1 10 10: evstwho[x] */ + INVALID, /* 1 10 11 */ + { 4, ST+E4 }, /* 1 11 00: evstwwe[x] */ + INVALID, /* 1 11 01 */ + { 4, ST+E4 }, /* 1 11 10: evstwwo[x] */ + INVALID, /* 1 11 11 */ +}; + +#define EVLDD 0x00 +#define EVLDW 0x01 +#define EVLDH 0x02 +#define EVLHHESPLAT 0x04 +#define EVLHHOUSPLAT 0x06 +#define EVLHHOSSPLAT 0x07 +#define EVLWHE 0x08 +#define EVLWHOU 0x0A +#define EVLWHOS 0x0B +#define EVLWWSPLAT 0x0C +#define EVLWHSPLAT 0x0E +#define EVSTDD 0x10 +#define EVSTDW 0x11 +#define EVSTDH 0x12 +#define EVSTWHE 0x18 +#define EVSTWHO 0x1A +#define EVSTWWE 0x1C +#define EVSTWWO 0x1E + +/* + * Emulate SPE loads and stores. + * Only Book-E has these instructions, and it does true little-endian, + * so we don't need the address swizzling. + */ +static int emulate_spe(struct pt_regs *regs, unsigned int reg, + unsigned int instr) +{ + int ret; + union { + u64 ll; + u32 w[2]; + u16 h[4]; + u8 v[8]; + } data, temp; + unsigned char __user *p, *addr; + unsigned long *evr = ¤t->thread.evr[reg]; + unsigned int nb, flags; + + instr = (instr >> 1) & 0x1f; + + /* DAR has the operand effective address */ + addr = (unsigned char __user *)regs->dar; + + nb = spe_aligninfo[instr].len; + flags = spe_aligninfo[instr].flags; + + /* Verify the address of the operand */ + if (unlikely(user_mode(regs) && + !access_ok((flags & ST ? VERIFY_WRITE : VERIFY_READ), + addr, nb))) + return -EFAULT; + + /* userland only */ + if (unlikely(!user_mode(regs))) + return 0; + + flush_spe_to_thread(current); + + /* If we are loading, get the data from user space, else + * get it from register values + */ + if (flags & ST) { + data.ll = 0; + switch (instr) { + case EVSTDD: + case EVSTDW: + case EVSTDH: + data.w[0] = *evr; + data.w[1] = regs->gpr[reg]; + break; + case EVSTWHE: + data.h[2] = *evr >> 16; + data.h[3] = regs->gpr[reg] >> 16; + break; + case EVSTWHO: + data.h[2] = *evr & 0xffff; + data.h[3] = regs->gpr[reg] & 0xffff; + break; + case EVSTWWE: + data.w[1] = *evr; + break; + case EVSTWWO: + data.w[1] = regs->gpr[reg]; + break; + default: + return -EINVAL; + } + } else { + temp.ll = data.ll = 0; + ret = 0; + p = addr; + + switch (nb) { + case 8: + ret |= __get_user_inatomic(temp.v[0], p++); + ret |= __get_user_inatomic(temp.v[1], p++); + ret |= __get_user_inatomic(temp.v[2], p++); + ret |= __get_user_inatomic(temp.v[3], p++); + case 4: + ret |= __get_user_inatomic(temp.v[4], p++); + ret |= __get_user_inatomic(temp.v[5], p++); + case 2: + ret |= __get_user_inatomic(temp.v[6], p++); + ret |= __get_user_inatomic(temp.v[7], p++); + if (unlikely(ret)) + return -EFAULT; + } + + switch (instr) { + case EVLDD: + case EVLDW: + case EVLDH: + data.ll = temp.ll; + break; + case EVLHHESPLAT: + data.h[0] = temp.h[3]; + data.h[2] = temp.h[3]; + break; + case EVLHHOUSPLAT: + case EVLHHOSSPLAT: + data.h[1] = temp.h[3]; + data.h[3] = temp.h[3]; + break; + case EVLWHE: + data.h[0] = temp.h[2]; + data.h[2] = temp.h[3]; + break; + case EVLWHOU: + case EVLWHOS: + data.h[1] = temp.h[2]; + data.h[3] = temp.h[3]; + break; + case EVLWWSPLAT: + data.w[0] = temp.w[1]; + data.w[1] = temp.w[1]; + break; + case EVLWHSPLAT: + data.h[0] = temp.h[2]; + data.h[1] = temp.h[2]; + data.h[2] = temp.h[3]; + data.h[3] = temp.h[3]; + break; + default: + return -EINVAL; + } + } + + if (flags & SW) { + switch (flags & 0xf0) { + case E8: + data.ll = swab64(data.ll); + break; + case E4: + data.w[0] = swab32(data.w[0]); + data.w[1] = swab32(data.w[1]); + break; + /* Its half word endian */ + default: + data.h[0] = swab16(data.h[0]); + data.h[1] = swab16(data.h[1]); + data.h[2] = swab16(data.h[2]); + data.h[3] = swab16(data.h[3]); + break; + } + } + + if (flags & SE) { + data.w[0] = (s16)data.h[1]; + data.w[1] = (s16)data.h[3]; + } + + /* Store result to memory or update registers */ + if (flags & ST) { + ret = 0; + p = addr; + switch (nb) { + case 8: + ret |= __put_user_inatomic(data.v[0], p++); + ret |= __put_user_inatomic(data.v[1], p++); + ret |= __put_user_inatomic(data.v[2], p++); + ret |= __put_user_inatomic(data.v[3], p++); + case 4: + ret |= __put_user_inatomic(data.v[4], p++); + ret |= __put_user_inatomic(data.v[5], p++); + case 2: + ret |= __put_user_inatomic(data.v[6], p++); + ret |= __put_user_inatomic(data.v[7], p++); + } + if (unlikely(ret)) + return -EFAULT; + } else { + *evr = data.w[0]; + regs->gpr[reg] = data.w[1]; + } + + return 1; +} +#endif /* CONFIG_SPE */ + +#ifdef CONFIG_VSX +/* + * Emulate VSX instructions... + */ +static int emulate_vsx(unsigned char __user *addr, unsigned int reg, + unsigned int areg, struct pt_regs *regs, + unsigned int flags, unsigned int length, + unsigned int elsize) +{ + char *ptr; + unsigned long *lptr; + int ret = 0; + int sw = 0; + int i, j; + + /* userland only */ + if (unlikely(!user_mode(regs))) + return 0; + + flush_vsx_to_thread(current); + + if (reg < 32) + ptr = (char *) ¤t->thread.fp_state.fpr[reg][0]; + else + ptr = (char *) ¤t->thread.vr_state.vr[reg - 32]; + + lptr = (unsigned long *) ptr; + +#ifdef __LITTLE_ENDIAN__ + if (flags & SW) { + elsize = length; + sw = length-1; + } else { + /* + * The elements are BE ordered, even in LE mode, so process + * them in reverse order. + */ + addr += length - elsize; + + /* 8 byte memory accesses go in the top 8 bytes of the VR */ + if (length == 8) + ptr += 8; + } +#else + if (flags & SW) + sw = elsize-1; +#endif + + for (j = 0; j < length; j += elsize) { + for (i = 0; i < elsize; ++i) { + if (flags & ST) + ret |= __put_user(ptr[i^sw], addr + i); + else + ret |= __get_user(ptr[i^sw], addr + i); + } + ptr += elsize; +#ifdef __LITTLE_ENDIAN__ + addr -= elsize; +#else + addr += elsize; +#endif + } + +#ifdef __BIG_ENDIAN__ +#define VSX_HI 0 +#define VSX_LO 1 +#else +#define VSX_HI 1 +#define VSX_LO 0 +#endif + + if (!ret) { + if (flags & U) + regs->gpr[areg] = regs->dar; + + /* Splat load copies the same data to top and bottom 8 bytes */ + if (flags & SPLT) + lptr[VSX_LO] = lptr[VSX_HI]; + /* For 8 byte loads, zero the low 8 bytes */ + else if (!(flags & ST) && (8 == length)) + lptr[VSX_LO] = 0; + } else + return -EFAULT; + + return 1; +} +#endif + +/* + * Called on alignment exception. Attempts to fixup + * + * Return 1 on success + * Return 0 if unable to handle the interrupt + * Return -EFAULT if data address is bad + */ + +int fix_alignment(struct pt_regs *regs) +{ + unsigned int instr, nb, flags, instruction = 0; + unsigned int reg, areg; + unsigned int dsisr; + unsigned char __user *addr; + unsigned long p, swiz; + int ret, i; + union data { + u64 ll; + double dd; + unsigned char v[8]; + struct { +#ifdef __LITTLE_ENDIAN__ + int low32; + unsigned hi32; +#else + unsigned hi32; + int low32; +#endif + } x32; + struct { +#ifdef __LITTLE_ENDIAN__ + short low16; + unsigned char hi48[6]; +#else + unsigned char hi48[6]; + short low16; +#endif + } x16; + } data; + + /* + * We require a complete register set, if not, then our assembly + * is broken + */ + CHECK_FULL_REGS(regs); + + dsisr = regs->dsisr; + + /* Some processors don't provide us with a DSISR we can use here, + * let's make one up from the instruction + */ + if (cpu_has_feature(CPU_FTR_NODSISRALIGN)) { + unsigned long pc = regs->nip; + + if (cpu_has_feature(CPU_FTR_PPC_LE) && (regs->msr & MSR_LE)) + pc ^= 4; + if (unlikely(__get_user_inatomic(instr, + (unsigned int __user *)pc))) + return -EFAULT; + if (cpu_has_feature(CPU_FTR_REAL_LE) && (regs->msr & MSR_LE)) + instr = cpu_to_le32(instr); + dsisr = make_dsisr(instr); + instruction = instr; + } + + /* extract the operation and registers from the dsisr */ + reg = (dsisr >> 5) & 0x1f; /* source/dest register */ + areg = dsisr & 0x1f; /* register to update */ + +#ifdef CONFIG_SPE + if ((instr >> 26) == 0x4) { + PPC_WARN_ALIGNMENT(spe, regs); + return emulate_spe(regs, reg, instr); + } +#endif + + instr = (dsisr >> 10) & 0x7f; + instr |= (dsisr >> 13) & 0x60; + + /* Lookup the operation in our table */ + nb = aligninfo[instr].len; + flags = aligninfo[instr].flags; + + /* ldbrx/stdbrx overlap lfs/stfs in the DSISR unfortunately */ + if (IS_XFORM(instruction) && ((instruction >> 1) & 0x3ff) == 532) { + nb = 8; + flags = LD+SW; + } else if (IS_XFORM(instruction) && + ((instruction >> 1) & 0x3ff) == 660) { + nb = 8; + flags = ST+SW; + } + + /* Byteswap little endian loads and stores */ + swiz = 0; + if ((regs->msr & MSR_LE) != (MSR_KERNEL & MSR_LE)) { + flags ^= SW; +#ifdef __BIG_ENDIAN__ + /* + * So-called "PowerPC little endian" mode works by + * swizzling addresses rather than by actually doing + * any byte-swapping. To emulate this, we XOR each + * byte address with 7. We also byte-swap, because + * the processor's address swizzling depends on the + * operand size (it xors the address with 7 for bytes, + * 6 for halfwords, 4 for words, 0 for doublewords) but + * we will xor with 7 and load/store each byte separately. + */ + if (cpu_has_feature(CPU_FTR_PPC_LE)) + swiz = 7; +#endif + } + + /* DAR has the operand effective address */ + addr = (unsigned char __user *)regs->dar; + +#ifdef CONFIG_VSX + if ((instruction & 0xfc00003e) == 0x7c000018) { + unsigned int elsize; + + /* Additional register addressing bit (64 VSX vs 32 FPR/GPR) */ + reg |= (instruction & 0x1) << 5; + /* Simple inline decoder instead of a table */ + /* VSX has only 8 and 16 byte memory accesses */ + nb = 8; + if (instruction & 0x200) + nb = 16; + + /* Vector stores in little-endian mode swap individual + elements, so process them separately */ + elsize = 4; + if (instruction & 0x80) + elsize = 8; + + flags = 0; + if ((regs->msr & MSR_LE) != (MSR_KERNEL & MSR_LE)) + flags |= SW; + if (instruction & 0x100) + flags |= ST; + if (instruction & 0x040) + flags |= U; + /* splat load needs a special decoder */ + if ((instruction & 0x400) == 0){ + flags |= SPLT; + nb = 8; + } + PPC_WARN_ALIGNMENT(vsx, regs); + return emulate_vsx(addr, reg, areg, regs, flags, nb, elsize); + } +#endif + /* A size of 0 indicates an instruction we don't support, with + * the exception of DCBZ which is handled as a special case here + */ + if (instr == DCBZ) { + PPC_WARN_ALIGNMENT(dcbz, regs); + return emulate_dcbz(regs, addr); + } + if (unlikely(nb == 0)) + return 0; + + /* Load/Store Multiple instructions are handled in their own + * function + */ + if (flags & M) { + PPC_WARN_ALIGNMENT(multiple, regs); + return emulate_multiple(regs, addr, reg, nb, + flags, instr, swiz); + } + + /* Verify the address of the operand */ + if (unlikely(user_mode(regs) && + !access_ok((flags & ST ? VERIFY_WRITE : VERIFY_READ), + addr, nb))) + return -EFAULT; + + /* Force the fprs into the save area so we can reference them */ + if (flags & F) { + /* userland only */ + if (unlikely(!user_mode(regs))) + return 0; + flush_fp_to_thread(current); + } + + if (nb == 16) { + if (flags & F) { + /* Special case for 16-byte FP loads and stores */ + PPC_WARN_ALIGNMENT(fp_pair, regs); + return emulate_fp_pair(addr, reg, flags); + } else { +#ifdef CONFIG_PPC64 + /* Special case for 16-byte loads and stores */ + PPC_WARN_ALIGNMENT(lq_stq, regs); + return emulate_lq_stq(regs, addr, reg, flags); +#else + return 0; +#endif + } + } + + PPC_WARN_ALIGNMENT(unaligned, regs); + + /* If we are loading, get the data from user space, else + * get it from register values + */ + if (!(flags & ST)) { + unsigned int start = 0; + + switch (nb) { + case 4: + start = offsetof(union data, x32.low32); + break; + case 2: + start = offsetof(union data, x16.low16); + break; + } + + data.ll = 0; + ret = 0; + p = (unsigned long)addr; + + for (i = 0; i < nb; i++) + ret |= __get_user_inatomic(data.v[start + i], + SWIZ_PTR(p++)); + + if (unlikely(ret)) + return -EFAULT; + + } else if (flags & F) { + data.ll = current->thread.TS_FPR(reg); + if (flags & S) { + /* Single-precision FP store requires conversion... */ +#ifdef CONFIG_PPC_FPU + preempt_disable(); + enable_kernel_fp(); + cvt_df(&data.dd, (float *)&data.x32.low32); + preempt_enable(); +#else + return 0; +#endif + } + } else + data.ll = regs->gpr[reg]; + + if (flags & SW) { + switch (nb) { + case 8: + data.ll = swab64(data.ll); + break; + case 4: + data.x32.low32 = swab32(data.x32.low32); + break; + case 2: + data.x16.low16 = swab16(data.x16.low16); + break; + } + } + + /* Perform other misc operations like sign extension + * or floating point single precision conversion + */ + switch (flags & ~(U|SW)) { + case LD+SE: /* sign extending integer loads */ + case LD+F+SE: /* sign extend for lfiwax */ + if ( nb == 2 ) + data.ll = data.x16.low16; + else /* nb must be 4 */ + data.ll = data.x32.low32; + break; + + /* Single-precision FP load requires conversion... */ + case LD+F+S: +#ifdef CONFIG_PPC_FPU + preempt_disable(); + enable_kernel_fp(); + cvt_fd((float *)&data.x32.low32, &data.dd); + preempt_enable(); +#else + return 0; +#endif + break; + } + + /* Store result to memory or update registers */ + if (flags & ST) { + unsigned int start = 0; + + switch (nb) { + case 4: + start = offsetof(union data, x32.low32); + break; + case 2: + start = offsetof(union data, x16.low16); + break; + } + + ret = 0; + p = (unsigned long)addr; + + for (i = 0; i < nb; i++) + ret |= __put_user_inatomic(data.v[start + i], + SWIZ_PTR(p++)); + + if (unlikely(ret)) + return -EFAULT; + } else if (flags & F) + current->thread.TS_FPR(reg) = data.ll; + else + regs->gpr[reg] = data.ll; + + /* Update RA as needed */ + if (flags & U) + regs->gpr[areg] = regs->dar; + + return 1; +} |