diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/ppc64/kernel/align.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/ppc64/kernel/align.c')
-rw-r--r-- | arch/ppc64/kernel/align.c | 396 |
1 files changed, 396 insertions, 0 deletions
diff --git a/arch/ppc64/kernel/align.c b/arch/ppc64/kernel/align.c new file mode 100644 index 00000000000..330e7ef8142 --- /dev/null +++ b/arch/ppc64/kernel/align.c @@ -0,0 +1,396 @@ +/* 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 + * + * 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/system.h> +#include <asm/cache.h> +#include <asm/cputable.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 } + +#define LD 1 /* load */ +#define ST 2 /* store */ +#define SE 4 /* sign-extend value */ +#define F 8 /* to/from fp regs */ +#define U 0x10 /* update index register */ +#define M 0x20 /* multiple load/store */ +#define SW 0x40 /* byte swap */ + +#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 }, /* 00 0 1000: lfs */ + { 8, LD+F }, /* 00 0 1001: lfd */ + { 4, ST+F }, /* 00 0 1010: stfs */ + { 8, ST+F }, /* 00 0 1011: stfd */ + INVALID, /* 00 0 1100 */ + { 8, LD }, /* 00 0 1101: ld */ + INVALID, /* 00 0 1110 */ + { 8, ST }, /* 00 0 1111: std */ + { 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+U }, /* 00 1 1000: lfsu */ + { 8, LD+F+U }, /* 00 1 1001: lfdu */ + { 4, ST+F+U }, /* 00 1 1010: stfsu */ + { 8, ST+F+U }, /* 00 1 1011: stfdu */ + INVALID, /* 00 1 1100 */ + INVALID, /* 00 1 1101 */ + INVALID, /* 00 1 1110 */ + 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 */ + { 0, LD }, /* 01 0 1000: lswx */ + { 0, LD }, /* 01 0 1001: lswi */ + { 0, ST }, /* 01 0 1010: stswx */ + { 0, ST }, /* 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 */ + { 0, ST }, /* 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 */ + { L1_CACHE_BYTES, ST }, /* 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 }, /* 11 0 1000: lfsx */ + { 8, LD+F }, /* 11 0 1001: lfdx */ + { 4, ST+F }, /* 11 0 1010: stfsx */ + { 8, ST+F }, /* 11 0 1011: stfdx */ + INVALID, /* 11 0 1100 */ + { 8, LD+M }, /* 11 0 1101: lmd */ + INVALID, /* 11 0 1110 */ + { 8, ST+M }, /* 11 0 1111: stmd */ + { 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+U }, /* 11 1 1000: lfsux */ + { 8, LD+F+U }, /* 11 1 1001: lfdux */ + { 4, ST+F+U }, /* 11 1 1010: stfsux */ + { 8, ST+F+U }, /* 11 1 1011: stfdux */ + INVALID, /* 11 1 1100 */ + INVALID, /* 11 1 1101 */ + INVALID, /* 11 1 1110 */ + INVALID, /* 11 1 1111 */ +}; + +#define SWAP(a, b) (t = (a), (a) = (b), (b) = t) + +static inline unsigned make_dsisr(unsigned instr) +{ + unsigned dsisr; + + /* create a DSISR value from the instruction */ + dsisr = (instr & 0x03ff0000) >> 16; /* bits 6:15 --> 22:31 */ + + if ( IS_XFORM(instr) ) { + dsisr |= (instr & 0x00000006) << 14; /* bits 29:30 --> 15:16 */ + dsisr |= (instr & 0x00000040) << 8; /* bit 25 --> 17 */ + dsisr |= (instr & 0x00000780) << 3; /* bits 21:24 --> 18:21 */ + } + else { + dsisr |= (instr & 0x04000000) >> 12; /* bit 5 --> 17 */ + dsisr |= (instr & 0x78000000) >> 17; /* bits 1: 4 --> 18:21 */ + if ( IS_DSFORM(instr) ) { + dsisr |= (instr & 0x00000003) << 18; /* bits 30:31 --> 12:13 */ + } + } + + return dsisr; +} + +int +fix_alignment(struct pt_regs *regs) +{ + unsigned int instr, nb, flags; + int t; + unsigned long reg, areg; + unsigned long i; + int ret; + unsigned dsisr; + unsigned char __user *addr; + unsigned char __user *p; + unsigned long __user *lp; + union { + long ll; + double dd; + unsigned char v[8]; + struct { + unsigned hi32; + int low32; + } x32; + struct { + unsigned char hi48[6]; + short low16; + } x16; + } data; + + /* + * Return 1 on success + * Return 0 if unable to handle the interrupt + * Return -EFAULT if data address is bad + */ + + dsisr = regs->dsisr; + + if (cpu_has_feature(CPU_FTR_NODSISRALIGN)) { + unsigned int real_instr; + if (__get_user(real_instr, (unsigned int __user *)regs->nip)) + return 0; + dsisr = make_dsisr(real_instr); + } + + /* extract the operation and registers from the dsisr */ + reg = (dsisr >> 5) & 0x1f; /* source/dest register */ + areg = dsisr & 0x1f; /* register to update */ + instr = (dsisr >> 10) & 0x7f; + instr |= (dsisr >> 13) & 0x60; + + /* Lookup the operation in our table */ + nb = aligninfo[instr].len; + flags = aligninfo[instr].flags; + + /* DAR has the operand effective address */ + addr = (unsigned char __user *)regs->dar; + + /* A size of 0 indicates an instruction we don't support */ + /* we also don't support the multiples (lmw, stmw, lmd, stmd) */ + if ((nb == 0) || (flags & M)) + return 0; /* too hard or invalid instruction */ + + /* + * Special handling for dcbz + * dcbz may give an alignment exception for accesses to caching inhibited + * storage + */ + if (instr == DCBZ) + addr = (unsigned char __user *) ((unsigned long)addr & -L1_CACHE_BYTES); + + /* Verify the address of the operand */ + if (user_mode(regs)) { + if (!access_ok((flags & ST? VERIFY_WRITE: VERIFY_READ), addr, nb)) + return -EFAULT; /* bad address */ + } + + /* Force the fprs into the save area so we can reference them */ + if (flags & F) { + if (!user_mode(regs)) + return 0; + flush_fp_to_thread(current); + } + + /* If we are loading, get the data from user space */ + if (flags & LD) { + data.ll = 0; + ret = 0; + p = addr; + switch (nb) { + case 8: + ret |= __get_user(data.v[0], p++); + ret |= __get_user(data.v[1], p++); + ret |= __get_user(data.v[2], p++); + ret |= __get_user(data.v[3], p++); + case 4: + ret |= __get_user(data.v[4], p++); + ret |= __get_user(data.v[5], p++); + case 2: + ret |= __get_user(data.v[6], p++); + ret |= __get_user(data.v[7], p++); + if (ret) + return -EFAULT; + } + } + + /* If we are storing, get the data from the saved gpr or fpr */ + if (flags & ST) { + if (flags & F) { + if (nb == 4) { + /* Doing stfs, have to convert to single */ + preempt_disable(); + enable_kernel_fp(); + cvt_df(¤t->thread.fpr[reg], (float *)&data.v[4], ¤t->thread.fpscr); + disable_kernel_fp(); + preempt_enable(); + } + else + data.dd = current->thread.fpr[reg]; + } + else + data.ll = regs->gpr[reg]; + } + + /* Swap bytes as needed */ + if (flags & SW) { + if (nb == 2) + SWAP(data.v[6], data.v[7]); + else { /* nb must be 4 */ + SWAP(data.v[4], data.v[7]); + SWAP(data.v[5], data.v[6]); + } + } + + /* Sign extend as needed */ + if (flags & SE) { + if ( nb == 2 ) + data.ll = data.x16.low16; + else /* nb must be 4 */ + data.ll = data.x32.low32; + } + + /* If we are loading, move the data to the gpr or fpr */ + if (flags & LD) { + if (flags & F) { + if (nb == 4) { + /* Doing lfs, have to convert to double */ + preempt_disable(); + enable_kernel_fp(); + cvt_fd((float *)&data.v[4], ¤t->thread.fpr[reg], ¤t->thread.fpscr); + disable_kernel_fp(); + preempt_enable(); + } + else + current->thread.fpr[reg] = data.dd; + } + else + regs->gpr[reg] = data.ll; + } + + /* If we are storing, copy the data to the user */ + if (flags & ST) { + ret = 0; + p = addr; + switch (nb) { + case 128: /* Special case - must be dcbz */ + lp = (unsigned long __user *)p; + for (i = 0; i < L1_CACHE_BYTES / sizeof(long); ++i) + ret |= __put_user(0, lp++); + break; + case 8: + ret |= __put_user(data.v[0], p++); + ret |= __put_user(data.v[1], p++); + ret |= __put_user(data.v[2], p++); + ret |= __put_user(data.v[3], p++); + case 4: + ret |= __put_user(data.v[4], p++); + ret |= __put_user(data.v[5], p++); + case 2: + ret |= __put_user(data.v[6], p++); + ret |= __put_user(data.v[7], p++); + } + if (ret) + return -EFAULT; + } + + /* Update RA as needed */ + if (flags & U) { + regs->gpr[areg] = regs->dar; + } + + return 1; +} + |