From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds@ppc970.osdl.org>
Date: Sat, 16 Apr 2005 15:20:36 -0700
Subject: Linux-2.6.12-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!
---
 arch/ppc/kernel/align.c | 398 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 398 insertions(+)
 create mode 100644 arch/ppc/kernel/align.c

(limited to 'arch/ppc/kernel/align.c')

diff --git a/arch/ppc/kernel/align.c b/arch/ppc/kernel/align.c
new file mode 100644
index 0000000..79c9294
--- /dev/null
+++ b/arch/ppc/kernel/align.c
@@ -0,0 +1,398 @@
+/*
+ * 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.
+ */
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <asm/ptrace.h>
+#include <asm/processor.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <asm/cache.h>
+
+struct aligninfo {
+	unsigned char len;
+	unsigned char flags;
+};
+
+#if defined(CONFIG_4xx) || defined(CONFIG_POWER4) || defined(CONFIG_BOOKE)
+#define	OPCD(inst)	(((inst) & 0xFC000000) >> 26)
+#define	RS(inst)	(((inst) & 0x03E00000) >> 21)
+#define	RA(inst)	(((inst) & 0x001F0000) >> 16)
+#define	IS_XFORM(code)	((code) == 31)
+#endif
+
+#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 S	0x40	/* single-precision fp, or byte-swap value */
+#define SX	0x40	/* byte count in XER */
+#define HARD	0x80	/* string, stwcx. */
+
+#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 */
+	INVALID,		/* 00 0 1101: ld/ldu/lwa */
+	INVALID,		/* 00 0 1110 */
+	INVALID,		/* 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 */
+	INVALID,		/* 00 1 1100 */
+	INVALID,		/* 00 1 1101 */
+	INVALID,		/* 00 1 1110 */
+	INVALID,		/* 00 1 1111 */
+	INVALID,		/* 01 0 0000: ldx */
+	INVALID,		/* 01 0 0001 */
+	INVALID,		/* 01 0 0010: stdx */
+	INVALID,		/* 01 0 0011 */
+	INVALID,		/* 01 0 0100 */
+	INVALID,		/* 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 */
+	INVALID,		/* 01 0 1101 */
+	INVALID,		/* 01 0 1110 */
+	INVALID,		/* 01 0 1111 */
+	INVALID,		/* 01 1 0000: ldux */
+	INVALID,		/* 01 1 0001 */
+	INVALID,		/* 01 1 0010: stdux */
+	INVALID,		/* 01 1 0011 */
+	INVALID,		/* 01 1 0100 */
+	INVALID,		/* 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+HARD },		/* 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+S },		/* 10 0 1000: lwbrx */
+	INVALID,		/* 10 0 1001 */
+	{ 4, ST+S },		/* 10 0 1010: stwbrx */
+	INVALID,		/* 10 0 1011 */
+	{ 2, LD+S },		/* 10 0 1100: lhbrx */
+	INVALID,		/* 10 0 1101 */
+	{ 2, ST+S },		/* 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 */
+	INVALID,		/* 11 0 1100 */
+	INVALID,		/* 11 0 1101: lmd */
+	INVALID,		/* 11 0 1110 */
+	INVALID,		/* 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+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 */
+	INVALID,		/* 11 1 1101 */
+	INVALID,		/* 11 1 1110 */
+	INVALID,		/* 11 1 1111 */
+};
+
+#define SWAP(a, b)	(t = (a), (a) = (b), (b) = t)
+
+int
+fix_alignment(struct pt_regs *regs)
+{
+	int instr, nb, flags;
+#if defined(CONFIG_4xx) || defined(CONFIG_POWER4) || defined(CONFIG_BOOKE)
+	int opcode, f1, f2, f3;
+#endif
+	int i, t;
+	int reg, areg;
+	int offset, nb0;
+	unsigned char __user *addr;
+	unsigned char *rptr;
+	union {
+		long l;
+		float f;
+		double d;
+		unsigned char v[8];
+	} data;
+
+	CHECK_FULL_REGS(regs);
+
+#if defined(CONFIG_4xx) || defined(CONFIG_POWER4) || defined(CONFIG_BOOKE)
+	/* The 4xx-family & Book-E processors have no DSISR register,
+	 * so we emulate it.
+	 * The POWER4 has a DSISR register but doesn't set it on
+	 * an alignment fault.  -- paulus
+	 */
+
+	if (__get_user(instr, (unsigned int __user *) regs->nip))
+		return 0;
+	opcode = OPCD(instr);
+	reg = RS(instr);
+	areg = RA(instr);
+
+	if (!IS_XFORM(opcode)) {
+		f1 = 0;
+		f2 = (instr & 0x04000000) >> 26;
+		f3 = (instr & 0x78000000) >> 27;
+	} else {
+		f1 = (instr & 0x00000006) >> 1;
+		f2 = (instr & 0x00000040) >> 6;
+		f3 = (instr & 0x00000780) >> 7;
+	}
+
+	instr = ((f1 << 5) | (f2 << 4) | f3);
+#else
+	reg = (regs->dsisr >> 5) & 0x1f;	/* source/dest register */
+	areg = regs->dsisr & 0x1f;		/* register to update */
+	instr = (regs->dsisr >> 10) & 0x7f;
+#endif
+
+	nb = aligninfo[instr].len;
+	if (nb == 0) {
+		long __user *p;
+		int i;
+
+		if (instr != DCBZ)
+			return 0;	/* too hard or invalid instruction */
+		/*
+		 * 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.
+		 */
+		p = (long __user *) (regs->dar & -L1_CACHE_BYTES);
+		if (user_mode(regs)
+		    && !access_ok(VERIFY_WRITE, p, L1_CACHE_BYTES))
+			return -EFAULT;
+		for (i = 0; i < L1_CACHE_BYTES / sizeof(long); ++i)
+			if (__put_user(0, p+i))
+				return -EFAULT;
+		return 1;
+	}
+
+	flags = aligninfo[instr].flags;
+	if ((flags & (LD|ST)) == 0)
+		return 0;
+
+	/* For the 4xx-family & Book-E processors, the 'dar' field of the
+	 * pt_regs structure is overloaded and is really from the DEAR.
+	 */
+
+	addr = (unsigned char __user *)regs->dar;
+
+	if (flags & M) {
+		/* lmw, stmw, lswi/x, stswi/x */
+		nb0 = 0;
+		if (flags & HARD) {
+			if (flags & SX) {
+				nb = regs->xer & 127;
+				if (nb == 0)
+					return 1;
+			} else {
+				if (__get_user(instr,
+					    (unsigned int __user *)regs->nip))
+					return 0;
+				nb = (instr >> 11) & 0x1f;
+				if (nb == 0)
+					nb = 32;
+			}
+			if (nb + reg * 4 > 128) {
+				nb0 = nb + reg * 4 - 128;
+				nb = 128 - reg * 4;
+			}
+		} else {
+			/* lwm, stmw */
+			nb = (32 - reg) * 4;
+		}
+		rptr = (unsigned char *) &regs->gpr[reg];
+		if (flags & LD) {
+			for (i = 0; i < nb; ++i)
+				if (__get_user(rptr[i], addr+i))
+					return -EFAULT;
+			if (nb0 > 0) {
+				rptr = (unsigned char *) &regs->gpr[0];
+				addr += nb;
+				for (i = 0; i < nb0; ++i)
+					if (__get_user(rptr[i], addr+i))
+						return -EFAULT;
+			}
+			for (; (i & 3) != 0; ++i)
+				rptr[i] = 0;
+		} else {
+			for (i = 0; i < nb; ++i)
+				if (__put_user(rptr[i], addr+i))
+					return -EFAULT;
+			if (nb0 > 0) {
+				rptr = (unsigned char *) &regs->gpr[0];
+				addr += nb;
+				for (i = 0; i < nb0; ++i)
+					if (__put_user(rptr[i], addr+i))
+						return -EFAULT;
+			}
+		}
+		return 1;
+	}
+
+	offset = 0;
+	if (nb < 4) {
+		/* read/write the least significant bits */
+		data.l = 0;
+		offset = 4 - nb;
+	}
+
+	/* 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 */
+	}
+
+	if (flags & F) {
+		preempt_disable();
+		if (regs->msr & MSR_FP)
+			giveup_fpu(current);
+		preempt_enable();
+	}
+
+	/* If we read the operand, copy it in, else get register values */
+	if (flags & LD) {
+		for (i = 0; i < nb; ++i)
+			if (__get_user(data.v[offset+i], addr+i))
+				return -EFAULT;
+	} else if (flags & F) {
+		data.d = current->thread.fpr[reg];
+	} else {
+		data.l = regs->gpr[reg];
+	}
+
+	switch (flags & ~U) {
+	case LD+SE:	/* sign extend */
+		if (data.v[2] >= 0x80)
+			data.v[0] = data.v[1] = -1;
+		break;
+
+	case LD+S:	/* byte-swap */
+	case ST+S:
+		if (nb == 2) {
+			SWAP(data.v[2], data.v[3]);
+		} else {
+			SWAP(data.v[0], data.v[3]);
+			SWAP(data.v[1], data.v[2]);
+		}
+		break;
+
+	/* Single-precision FP load and store require conversions... */
+	case LD+F+S:
+		preempt_disable();
+		enable_kernel_fp();
+		cvt_fd(&data.f, &data.d, &current->thread.fpscr);
+		preempt_enable();
+		break;
+	case ST+F+S:
+		preempt_disable();
+		enable_kernel_fp();
+		cvt_df(&data.d, &data.f, &current->thread.fpscr);
+		preempt_enable();
+		break;
+	}
+
+	if (flags & ST) {
+		for (i = 0; i < nb; ++i)
+			if (__put_user(data.v[offset+i], addr+i))
+				return -EFAULT;
+	} else if (flags & F) {
+		current->thread.fpr[reg] = data.d;
+	} else {
+		regs->gpr[reg] = data.l;
+	}
+
+	if (flags & U)
+		regs->gpr[areg] = regs->dar;
+
+	return 1;
+}
-- 
cgit v1.1