[PATCH] powerpc: merge align.c

This patch merges align.c, the result isn't quite what was in ppc64 nor
what was in ppc32 :) It should implement all the functionalities of both
though. Kumar, since you played with that in the past, I suppose you
have some test cases for verifying that it works properly before I dig
out the 601 machine ? :)

Since it's likely that I won't be able to test all scenario, code
inspection is much welcome.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

2 files changed, 1 insertions, 397 deletions

diff --git a/arch/ppc64/kernel/Makefile b/arch/ppc64/kernel/Makefile
index e876c21..5f0abdb 100644
--- a/arch/ppc64/kernel/Makefile
+++ b/arch/ppc64/kernel/Makefile
@@ -2,6 +2,6 @@
 # Makefile for the linux ppc64 kernel.
 #
 
-obj-y               +=	idle.o align.o
+obj-y               +=	idle.o
 
 obj-$(CONFIG_PPC_MULTIPLATFORM) += nvram.o
diff --git a/arch/ppc64/kernel/align.c b/arch/ppc64/kernel/align.c
deleted file mode 100644
index 256d5b5..0000000
--- a/arch/ppc64/kernel/align.c
+++ /dev/null
@@ -1,396 +0,0 @@
-/* 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(&current->thread.fpr[reg], (float *)&data.v[4], &current->thread);
-				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], &current->thread.fpr[reg], &current->thread);
-				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;
-}
-