unaligned.c

linux-2.6.15.6

/*
 *    Unaligned memory access handler
 *
 *    Copyright (C) 2001 Randolph Chung <[e-mail]>
 *    Significantly tweaked by LaMont Jones <[e-mail]>
 *
 *    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, or (at your option)
 *    any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <asm/uaccess.h>

/* #define DEBUG_UNALIGNED 1 */

#ifdef DEBUG_UNALIGNED
#define DPRINTF(fmt, args...) do { printk(KERN_DEBUG "%s:%d:%s ", __FILE__, __LINE__, __FUNCTION__ ); printk(KERN_DEBUG fmt, ##args ); } while (0)
#else
#define DPRINTF(fmt, args...)
#endif

#ifdef __LP64__
#define RFMT "%016lx"
#else
#define RFMT "%08lx"
#endif

#define FIXUP_BRANCH(lbl) \
	"\tldil L%%" #lbl ", %%r1\n"			\
	"\tldo R%%" #lbl "(%%r1), %%r1\n"		\
	"\tbv,n %%r0(%%r1)\n"

/* 1111 1100 0000 0000 0001 0011 1100 0000 */
#define OPCODE1(a,b,c)	((a)<<26|(b)<<12|(c)<<6) 
#define OPCODE2(a,b)	((a)<<26|(b)<<1)
#define OPCODE3(a,b)	((a)<<26|(b)<<2)
#define OPCODE4(a)	((a)<<26)
#define OPCODE1_MASK	OPCODE1(0x3f,1,0xf)
#define OPCODE2_MASK 	OPCODE2(0x3f,1)
#define OPCODE3_MASK	OPCODE3(0x3f,1)
#define OPCODE4_MASK    OPCODE4(0x3f)

/* skip LDB - never unaligned (index) */
#define OPCODE_LDH_I	OPCODE1(0x03,0,0x1)
#define OPCODE_LDW_I	OPCODE1(0x03,0,0x2)
#define OPCODE_LDD_I	OPCODE1(0x03,0,0x3)
#define OPCODE_LDDA_I	OPCODE1(0x03,0,0x4)
#define OPCODE_LDCD_I	OPCODE1(0x03,0,0x5)
#define OPCODE_LDWA_I	OPCODE1(0x03,0,0x6)
#define OPCODE_LDCW_I	OPCODE1(0x03,0,0x7)
/* skip LDB - never unaligned (short) */
#define OPCODE_LDH_S	OPCODE1(0x03,1,0x1)
#define OPCODE_LDW_S	OPCODE1(0x03,1,0x2)
#define OPCODE_LDD_S	OPCODE1(0x03,1,0x3)
#define OPCODE_LDDA_S	OPCODE1(0x03,1,0x4)
#define OPCODE_LDCD_S	OPCODE1(0x03,1,0x5)
#define OPCODE_LDWA_S	OPCODE1(0x03,1,0x6)
#define OPCODE_LDCW_S	OPCODE1(0x03,1,0x7)
/* skip STB - never unaligned */
#define OPCODE_STH	OPCODE1(0x03,1,0x9)
#define OPCODE_STW	OPCODE1(0x03,1,0xa)
#define OPCODE_STD	OPCODE1(0x03,1,0xb)
/* skip STBY - never unaligned */
/* skip STDBY - never unaligned */
#define OPCODE_STWA	OPCODE1(0x03,1,0xe)
#define OPCODE_STDA	OPCODE1(0x03,1,0xf)

#define OPCODE_FLDWX	OPCODE1(0x09,0,0x0)
#define OPCODE_FLDWXR	OPCODE1(0x09,0,0x1)
#define OPCODE_FSTWX	OPCODE1(0x09,0,0x8)
#define OPCODE_FSTWXR	OPCODE1(0x09,0,0x9)
#define OPCODE_FLDWS	OPCODE1(0x09,1,0x0)
#define OPCODE_FLDWSR	OPCODE1(0x09,1,0x1)
#define OPCODE_FSTWS	OPCODE1(0x09,1,0x8)
#define OPCODE_FSTWSR	OPCODE1(0x09,1,0x9)
#define OPCODE_FLDDX	OPCODE1(0x0b,0,0x0)
#define OPCODE_FSTDX	OPCODE1(0x0b,0,0x8)
#define OPCODE_FLDDS	OPCODE1(0x0b,1,0x0)
#define OPCODE_FSTDS	OPCODE1(0x0b,1,0x8)

#define OPCODE_LDD_L	OPCODE2(0x14,0)
#define OPCODE_FLDD_L	OPCODE2(0x14,1)
#define OPCODE_STD_L	OPCODE2(0x1c,0)
#define OPCODE_FSTD_L	OPCODE2(0x1c,1)

#define OPCODE_LDW_M	OPCODE3(0x17,1)
#define OPCODE_FLDW_L	OPCODE3(0x17,0)
#define OPCODE_FSTW_L	OPCODE3(0x1f,0)
#define OPCODE_STW_M	OPCODE3(0x1f,1)

#define OPCODE_LDH_L    OPCODE4(0x11)
#define OPCODE_LDW_L    OPCODE4(0x12)
#define OPCODE_LDWM     OPCODE4(0x13)
#define OPCODE_STH_L    OPCODE4(0x19)
#define OPCODE_STW_L    OPCODE4(0x1A)
#define OPCODE_STWM     OPCODE4(0x1B)

#define MAJOR_OP(i) (((i)>>26)&0x3f)
#define R1(i) (((i)>>21)&0x1f)
#define R2(i) (((i)>>16)&0x1f)
#define R3(i) ((i)&0x1f)
#define FR3(i) ((((i)<<1)&0x1f)|(((i)>>6)&1))
#define IM(i,n) (((i)>>1&((1<<(n-1))-1))|((i)&1?((0-1L)<<(n-1)):0))
#define IM5_2(i) IM((i)>>16,5)
#define IM5_3(i) IM((i),5)
#define IM14(i) IM((i),14)

#define ERR_NOTHANDLED	-1
#define ERR_PAGEFAULT	-2

int unaligned_enabled = 1;

void die_if_kernel (char *str, struct pt_regs *regs, long err);

static int emulate_ldh(struct pt_regs *regs, int toreg)
{
	unsigned long saddr = regs->ior;
	unsigned long val = 0;
	int ret;

	DPRINTF("load " RFMT ":" RFMT " to r%d for 2 bytes\n", 
		regs->isr, regs->ior, toreg);

	__asm__ __volatile__  (
"	mtsp	%4, %%sr1\n"
"1:	ldbs	0(%%sr1,%3), %%r20\n"
"2:	ldbs	1(%%sr1,%3), %0\n"
"	depw	%%r20, 23, 24, %0\n"
"	copy	%%r0, %1\n"
"3:	\n"
"	.section .fixup,\"ax\"\n"
"4:	ldi	-2, %1\n"
	FIXUP_BRANCH(3b)
"	.previous\n"
"	.section __ex_table,\"aw\"\n"
#ifdef __LP64__
"	.dword	1b,4b\n"
"	.dword  2b,4b\n"
#else
"	.word	1b,4b\n"
"	.word	2b,4b\n"
#endif
"	.previous\n"
	: "=r" (val), "=r" (ret)
	: "0" (val), "r" (saddr), "r" (regs->isr)
	: "r20" );

	DPRINTF("val = 0x" RFMT "\n", val);

	if (toreg)
		regs->gr[toreg] = val;

	return ret;
}

static int emulate_ldw(struct pt_regs *regs, int toreg, int flop)
{
	unsigned long saddr = regs->ior;
	unsigned long val = 0;
	int ret;

	DPRINTF("load " RFMT ":" RFMT " to r%d for 4 bytes\n", 
		regs->isr, regs->ior, toreg);

	__asm__ __volatile__  (
"	zdep	%3,28,2,%%r19\n"		/* r19=(ofs&3)*8 */
"	mtsp	%4, %%sr1\n"
"	depw	%%r0,31,2,%3\n"
"1:	ldw	0(%%sr1,%3),%0\n"
"2:	ldw	4(%%sr1,%3),%%r20\n"
"	subi	32,%%r19,%%r19\n"
"	mtctl	%%r19,11\n"
"	vshd	%0,%%r20,%0\n"
"	copy	%%r0, %1\n"
"3:	\n"
"	.section .fixup,\"ax\"\n"
"4:	ldi	-2, %1\n"
	FIXUP_BRANCH(3b)
"	.previous\n"
"	.section __ex_table,\"aw\"\n"
#ifdef __LP64__
"	.dword	1b,4b\n"
"	.dword  2b,4b\n"
#else
"	.word	1b,4b\n"
"	.word	2b,4b\n"
#endif
"	.previous\n"
	: "=r" (val), "=r" (ret)
	: "0" (val), "r" (saddr), "r" (regs->isr)
	: "r19", "r20" );

	DPRINTF("val = 0x" RFMT "\n", val);

	if (flop)
		((__u32*)(regs->fr))[toreg] = val;
	else if (toreg)
		regs->gr[toreg] = val;

	return ret;
}
static int emulate_ldd(struct pt_regs *regs, int toreg, int flop)
{
	unsigned long saddr = regs->ior;
	__u64 val = 0;
	int ret;

	DPRINTF("load " RFMT ":" RFMT " to r%d for 8 bytes\n", 
		regs->isr, regs->ior, toreg);
#ifdef CONFIG_PA20

#ifndef __LP64__
	if (!flop)
		return -1;
#endif
	__asm__ __volatile__  (
"	depd,z	%3,60,3,%%r19\n"		/* r19=(ofs&7)*8 */
"	mtsp	%4, %%sr1\n"
"	depd	%%r0,63,3,%3\n"
"1:	ldd	0(%%sr1,%3),%0\n"
"2:	ldd	8(%%sr1,%3),%%r20\n"
"	subi	64,%%r19,%%r19\n"
"	mtsar	%%r19\n"
"	shrpd	%0,%%r20,%%sar,%0\n"
"	copy	%%r0, %1\n"
"3:	\n"
"	.section .fixup,\"ax\"\n"
"4:	ldi	-2, %1\n"
	FIXUP_BRANCH(3b)
"	.previous\n"
"	.section __ex_table,\"aw\"\n"
#ifdef __LP64__
"	.dword	1b,4b\n"
"	.dword  2b,4b\n"
#else
"	.word	1b,4b\n"
"	.word	2b,4b\n"
#endif
"	.previous\n"
	: "=r" (val), "=r" (ret)
	: "0" (val), "r" (saddr), "r" (regs->isr)
	: "r19", "r20" );
#else
    {
	unsigned long valh=0,vall=0;
	__asm__ __volatile__  (
"	zdep	%5,29,2,%%r19\n"		/* r19=(ofs&3)*8 */
"	mtsp	%6, %%sr1\n"
"	dep	%%r0,31,2,%5\n"
"1:	ldw	0(%%sr1,%5),%0\n"
"2:	ldw	4(%%sr1,%5),%1\n"
"3:	ldw	8(%%sr1,%5),%%r20\n"
"	subi	32,%%r19,%%r19\n"
"	mtsar	%%r19\n"
"	vshd	%0,%1,%0\n"
"	vshd	%1,%%r20,%1\n"
"	copy	%%r0, %2\n"
"4:	\n"
"	.section .fixup,\"ax\"\n"
"5:	ldi	-2, %2\n"
	FIXUP_BRANCH(4b)
"	.previous\n"
"	.section __ex_table,\"aw\"\n"
#ifdef __LP64__
"	.dword	1b,5b\n"
"	.dword  2b,5b\n"
"	.dword	3b,5b\n"
#else
"	.word	1b,5b\n"
"	.word	2b,5b\n"
"	.word	3b,5b\n"
#endif
"	.previous\n"
	: "=r" (valh), "=r" (vall), "=r" (ret)
	: "0" (valh), "1" (vall), "r" (saddr), "r" (regs->isr)
	: "r19", "r20" );
	val=((__u64)valh<<32)|(__u64)vall;
    }
#endif

	DPRINTF("val = 0x%llx\n", val);

	if (flop)
		regs->fr[toreg] = val;
	else if (toreg)
		regs->gr[toreg] = val;

	return ret;
}

static int emulate_sth(struct pt_regs *regs, int frreg)
{
	unsigned long val = regs->gr[frreg];
	int ret;

	if (!frreg)
		val = 0;

	DPRINTF("store r%d (0x" RFMT ") to " RFMT ":" RFMT " for 2 bytes\n", frreg, 
		val, regs->isr, regs->ior);

	__asm__ __volatile__ (
"	mtsp %3, %%sr1\n"
"	extrw,u %1, 23, 8, %%r19\n"
"1:	stb %1, 1(%%sr1, %2)\n"
"2:	stb %%r19, 0(%%sr1, %2)\n"
"	copy	%%r0, %0\n"
"3:	\n"
"	.section .fixup,\"ax\"\n"
"4:	ldi	-2, %0\n"
	FIXUP_BRANCH(3b)
"	.previous\n"
"	.section __ex_table,\"aw\"\n"
#ifdef __LP64__
"	.dword	1b,4b\n"
"	.dword  2b,4b\n"
#else
"	.word	1b,4b\n"
"	.word	2b,4b\n"
#endif
"	.previous\n"
	: "=r" (ret)
	: "r" (val), "r" (regs->ior), "r" (regs->isr)
	: "r19" );

	return ret;
}

static int emulate_stw(struct pt_regs *regs, int frreg, int flop)
{
	unsigned long val;
	int ret;

	if (flop)
		val = ((__u32*)(regs->fr))[frreg];
	else if (frreg)
		val = regs->gr[frreg];
	else
		val = 0;

	DPRINTF("store r%d (0x" RFMT ") to " RFMT ":" RFMT " for 4 bytes\n", frreg, 
		val, regs->isr, regs->ior);


	__asm__ __volatile__ (
"	mtsp %3, %%sr1\n"
"	zdep	%2, 28, 2, %%r19\n"
"	dep	%%r0, 31, 2, %2\n"
"	mtsar	%%r19\n"
"	depwi,z	-2, %%sar, 32, %%r19\n"
"1:	ldw	0(%%sr1,%2),%%r20\n"
"2:	ldw	4(%%sr1,%2),%%r21\n"
"	vshd	%%r0, %1, %%r22\n"
"	vshd	%1, %%r0, %%r1\n"
"	and	%%r20, %%r19, %%r20\n"
"	andcm	%%r21, %%r19, %%r21\n"
"	or	%%r22, %%r20, %%r20\n"
"	or	%%r1, %%r21, %%r21\n"
"	stw	%%r20,0(%%sr1,%2)\n"
"	stw	%%r21,4(%%sr1,%2)\n"
"	copy	%%r0, %0\n"
"3:	\n"
"	.section .fixup,\"ax\"\n"
"4:	ldi	-2, %0\n"
	FIXUP_BRANCH(3b)
"	.previous\n"
"	.section __ex_table,\"aw\"\n"
#ifdef __LP64__
"	.dword	1b,4b\n"
"	.dword  2b,4b\n"
#else
"	.word	1b,4b\n"
"	.word	2b,4b\n"
#endif
"	.previous\n"
	: "=r" (ret)
	: "r" (val), "r" (regs->ior), "r" (regs->isr)
	: "r19", "r20", "r21", "r22", "r1" );

	return 0;
}
static int emulate_std(struct pt_regs *regs, int frreg, int flop)
{
	__u64 val;
	int ret;

	if (flop)
		val = regs->fr[frreg];
	else if (frreg)
		val = regs->gr[frreg];
	else
		val = 0;

	DPRINTF("store r%d (0x%016llx) to " RFMT ":" RFMT " for 8 bytes\n", frreg, 
		val,  regs->isr, regs->ior);

#ifdef CONFIG_PA20