/* 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> struct aligninfo { unsigned char len; unsigned char flags; }; #define IS_XFORM(inst) (((inst) >> 26) == 31) #define IS_DSFORM(inst) (((inst) >> 26) >= 56) #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 */ INVALID, /* 00 0 1100 */ { 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 */ INVALID, /* 10 0 1111 */ 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 */ }; /* * Create a DSISR value from the instruction */ static inline unsigned make_dsisr(unsigned instr) { unsigned dsisr; /* bits 6:15 --> 22:31 */ dsisr = (instr & 0x03ff0000) >> 16; if (IS_XFORM(instr)) { /* bits 29:30 --> 15:16 */ dsisr |= (instr & 0x00000006) << 14; /* bit 25 --> 17 */ dsisr |= (instr & 0x00000040) << 8; /* bits 21:24 --> 18:21 */ dsisr |= (instr & 0x00000780) << 3; } else { /* bit 5 --> 17 */ dsisr |= (instr & 0x04000000) >> 12; /* bits 1: 4 --> 18:21 */ dsisr |= (instr & 0x78000000) >> 17; /* bits 30:31 --> 12:13 */ if (IS_DSFORM(instr)) dsisr |= (instr & 0x00000003) << 18; } return dsisr; } /* * 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 (!(flags & F)) return 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_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); } /* Special case for 16-byte FP loads and stores */ if (nb == 16) { PPC_WARN_ALIGNMENT(fp_pair, regs); return emulate_fp_pair(addr, reg, flags); } 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; }