parisc/unaligned: Use EFAULT fixup handler in unaligned handlers

Convert the inline assembly code to use the automatic EFAULT exception
handler. With that the fixup code can be dropped.

The other change is to allow double-word only when a 64-bit kernel is
used instead of depending on CONFIG_PA20.

Signed-off-by: Helge Deller <deller@gmx.de>

1 files changed, 55 insertions, 105 deletions

diff --git a/arch/parisc/kernel/unaligned.c b/arch/parisc/kernel/unaligned.c
index 286cec4d86d7..857dcc790122 100644
--- a/arch/parisc/kernel/unaligned.c
+++ b/arch/parisc/kernel/unaligned.c
@@ -31,13 +31,6 @@
 #define RFMT "%08lx"
 #endif
 
-#define FIXUP_BRANCH(lbl) \
-	"\tldil L%%" #lbl ", %%r1\n"			\
-	"\tldo R%%" #lbl "(%%r1), %%r1\n"		\
-	"\tbv,n %%r0(%%r1)\n"
-/* If you use FIXUP_BRANCH, then you must list this clobber */
-#define FIXUP_BRANCH_CLOBBER "r1"
-
 /* 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)
@@ -114,7 +107,6 @@
 #define IM14(i) IM((i),14)
 
 #define ERR_NOTHANDLED	-1
-#define ERR_PAGEFAULT	-2
 
 int unaligned_enabled __read_mostly = 1;
 
@@ -122,7 +114,7 @@ static int emulate_ldh(struct pt_regs *regs, int toreg)
 {
 	unsigned long saddr = regs->ior;
 	unsigned long val = 0;
-	int ret;
+	ASM_EXCEPTIONTABLE_VAR(ret);
 
 	DPRINTF("load " RFMT ":" RFMT " to r%d for 2 bytes\n", 
 		regs->isr, regs->ior, toreg);
@@ -132,17 +124,12 @@ static int emulate_ldh(struct pt_regs *regs, int toreg)
 "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"
-	ASM_EXCEPTIONTABLE_ENTRY(1b, 4b)
-	ASM_EXCEPTIONTABLE_ENTRY(2b, 4b)
-	: "=r" (val), "=r" (ret)
+	ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 3b)
+	ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 3b)
+	: "=r" (val), "+r" (ret)
 	: "0" (val), "r" (saddr), "r" (regs->isr)
-	: "r20", FIXUP_BRANCH_CLOBBER );
+	: "r20" );
 
 	DPRINTF("val = 0x" RFMT "\n", val);
 
@@ -156,7 +143,7 @@ static int emulate_ldw(struct pt_regs *regs, int toreg, int flop)
 {
 	unsigned long saddr = regs->ior;
 	unsigned long val = 0;
-	int ret;
+	ASM_EXCEPTIONTABLE_VAR(ret);
 
 	DPRINTF("load " RFMT ":" RFMT " to r%d for 4 bytes\n", 
 		regs->isr, regs->ior, toreg);
@@ -170,17 +157,12 @@ static int emulate_ldw(struct pt_regs *regs, int toreg, int flop)
 "	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"
-	ASM_EXCEPTIONTABLE_ENTRY(1b, 4b)
-	ASM_EXCEPTIONTABLE_ENTRY(2b, 4b)
-	: "=r" (val), "=r" (ret)
+	ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 3b)
+	ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 3b)
+	: "=r" (val), "+r" (ret)
 	: "0" (val), "r" (saddr), "r" (regs->isr)
-	: "r19", "r20", FIXUP_BRANCH_CLOBBER );
+	: "r19", "r20" );
 
 	DPRINTF("val = 0x" RFMT "\n", val);
 
@@ -195,16 +177,15 @@ static int emulate_ldd(struct pt_regs *regs, int toreg, int flop)
 {
 	unsigned long saddr = regs->ior;
 	__u64 val = 0;
-	int ret;
+	ASM_EXCEPTIONTABLE_VAR(ret);
 
 	DPRINTF("load " RFMT ":" RFMT " to r%d for 8 bytes\n", 
 		regs->isr, regs->ior, toreg);
-#ifdef CONFIG_PA20
 
-#ifndef CONFIG_64BIT
-	if (!flop)
-		return -1;
-#endif
+	if (!IS_ENABLED(CONFIG_64BIT) && !flop)
+		return ERR_NOTHANDLED;
+
+#ifdef CONFIG_64BIT
 	__asm__ __volatile__  (
 "	depd,z	%3,60,3,%%r19\n"		/* r19=(ofs&7)*8 */
 "	mtsp	%4, %%sr1\n"
@@ -214,17 +195,12 @@ static int emulate_ldd(struct pt_regs *regs, int toreg, int flop)
 "	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"
-	ASM_EXCEPTIONTABLE_ENTRY(1b,4b)
-	ASM_EXCEPTIONTABLE_ENTRY(2b,4b)
-	: "=r" (val), "=r" (ret)
+	ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 3b)
+	ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 3b)
+	: "=r" (val), "+r" (ret)
 	: "0" (val), "r" (saddr), "r" (regs->isr)
-	: "r19", "r20", FIXUP_BRANCH_CLOBBER );
+	: "r19", "r20" );
 #else
     {
 	unsigned long valh=0,vall=0;
@@ -239,18 +215,13 @@ static int emulate_ldd(struct pt_regs *regs, int toreg, int flop)
 "	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"
-	ASM_EXCEPTIONTABLE_ENTRY(1b,5b)
-	ASM_EXCEPTIONTABLE_ENTRY(2b,5b)
-	ASM_EXCEPTIONTABLE_ENTRY(3b,5b)
-	: "=r" (valh), "=r" (vall), "=r" (ret)
+	ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 4b)
+	ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 4b)
+	ASM_EXCEPTIONTABLE_ENTRY_EFAULT(3b, 4b)
+	: "=r" (valh), "=r" (vall), "+r" (ret)
 	: "0" (valh), "1" (vall), "r" (saddr), "r" (regs->isr)
-	: "r19", "r20", FIXUP_BRANCH_CLOBBER );
+	: "r19", "r20" );
 	val=((__u64)valh<<32)|(__u64)vall;
     }
 #endif
@@ -268,7 +239,7 @@ static int emulate_ldd(struct pt_regs *regs, int toreg, int flop)
 static int emulate_sth(struct pt_regs *regs, int frreg)
 {
 	unsigned long val = regs->gr[frreg];
-	int ret;
+	ASM_EXCEPTIONTABLE_VAR(ret);
 
 	if (!frreg)
 		val = 0;
@@ -281,17 +252,12 @@ static int emulate_sth(struct pt_regs *regs, int frreg)
 "	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"
-	ASM_EXCEPTIONTABLE_ENTRY(1b,4b)
-	ASM_EXCEPTIONTABLE_ENTRY(2b,4b)
-	: "=r" (ret)
+	ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 3b)
+	ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 3b)
+	: "+r" (ret)
 	: "r" (val), "r" (regs->ior), "r" (regs->isr)
-	: "r19", FIXUP_BRANCH_CLOBBER );
+	: "r19" );
 
 	return ret;
 }
@@ -299,7 +265,7 @@ static int emulate_sth(struct pt_regs *regs, int frreg)
 static int emulate_stw(struct pt_regs *regs, int frreg, int flop)
 {
 	unsigned long val;
-	int ret;
+	ASM_EXCEPTIONTABLE_VAR(ret);
 
 	if (flop)
 		val = ((__u32*)(regs->fr))[frreg];
@@ -328,24 +294,19 @@ static int emulate_stw(struct pt_regs *regs, int frreg, int flop)
 "	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"
-	ASM_EXCEPTIONTABLE_ENTRY(1b,4b)
-	ASM_EXCEPTIONTABLE_ENTRY(2b,4b)
-	: "=r" (ret)
+	ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 3b)
+	ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 3b)
+	: "+r" (ret)
 	: "r" (val), "r" (regs->ior), "r" (regs->isr)
-	: "r19", "r20", "r21", "r22", "r1", FIXUP_BRANCH_CLOBBER );
+	: "r19", "r20", "r21", "r22", "r1" );
 
 	return ret;
 }
 static int emulate_std(struct pt_regs *regs, int frreg, int flop)
 {
 	__u64 val;
-	int ret;
+	ASM_EXCEPTIONTABLE_VAR(ret);
 
 	if (flop)
 		val = regs->fr[frreg];
@@ -357,11 +318,10 @@ static int emulate_std(struct pt_regs *regs, int frreg, int flop)
 	DPRINTF("store r%d (0x%016llx) to " RFMT ":" RFMT " for 8 bytes\n", frreg, 
 		val,  regs->isr, regs->ior);
 
-#ifdef CONFIG_PA20
-#ifndef CONFIG_64BIT
-	if (!flop)
-		return -1;
-#endif
+	if (!IS_ENABLED(CONFIG_64BIT) && !flop)
+		return ERR_NOTHANDLED;
+
+#ifdef CONFIG_64BIT
 	__asm__ __volatile__ (
 "	mtsp %3, %%sr1\n"
 "	depd,z	%2, 60, 3, %%r19\n"
@@ -378,19 +338,14 @@ static int emulate_std(struct pt_regs *regs, int frreg, int flop)
 "	or	%%r1, %%r21, %%r21\n"
 "3:	std	%%r20,0(%%sr1,%2)\n"
 "4:	std	%%r21,8(%%sr1,%2)\n"
-"	copy	%%r0, %0\n"
 "5:	\n"
-"	.section .fixup,\"ax\"\n"
-"6:	ldi	-2, %0\n"
-	FIXUP_BRANCH(5b)
-"	.previous\n"
-	ASM_EXCEPTIONTABLE_ENTRY(1b,6b)
-	ASM_EXCEPTIONTABLE_ENTRY(2b,6b)
-	ASM_EXCEPTIONTABLE_ENTRY(3b,6b)
-	ASM_EXCEPTIONTABLE_ENTRY(4b,6b)
-	: "=r" (ret)
+	ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 5b)
+	ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 5b)
+	ASM_EXCEPTIONTABLE_ENTRY_EFAULT(3b, 5b)
+	ASM_EXCEPTIONTABLE_ENTRY_EFAULT(4b, 5b)
+	: "+r" (ret)
 	: "r" (val), "r" (regs->ior), "r" (regs->isr)
-	: "r19", "r20", "r21", "r22", "r1", FIXUP_BRANCH_CLOBBER );
+	: "r19", "r20", "r21", "r22", "r1" );
 #else
     {
 	unsigned long valh=(val>>32),vall=(val&0xffffffffl);
@@ -412,20 +367,15 @@ static int emulate_std(struct pt_regs *regs, int frreg, int flop)
 "3:	stw	%1,0(%%sr1,%3)\n"
 "4:	stw	%%r1,4(%%sr1,%3)\n"
 "5:	stw	%2,8(%%sr1,%3)\n"
-"	copy	%%r0, %0\n"
 "6:	\n"
-"	.section .fixup,\"ax\"\n"
-"7:	ldi	-2, %0\n"
-	FIXUP_BRANCH(6b)
-"	.previous\n"
-	ASM_EXCEPTIONTABLE_ENTRY(1b,7b)
-	ASM_EXCEPTIONTABLE_ENTRY(2b,7b)
-	ASM_EXCEPTIONTABLE_ENTRY(3b,7b)
-	ASM_EXCEPTIONTABLE_ENTRY(4b,7b)
-	ASM_EXCEPTIONTABLE_ENTRY(5b,7b)
-	: "=r" (ret)
+	ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 6b)
+	ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 6b)
+	ASM_EXCEPTIONTABLE_ENTRY_EFAULT(3b, 6b)
+	ASM_EXCEPTIONTABLE_ENTRY_EFAULT(4b, 6b)
+	ASM_EXCEPTIONTABLE_ENTRY_EFAULT(5b, 6b)
+	: "+r" (ret)
 	: "r" (valh), "r" (vall), "r" (regs->ior), "r" (regs->isr)
-	: "r19", "r20", "r21", "r1", FIXUP_BRANCH_CLOBBER );
+	: "r19", "r20", "r21", "r1" );
     }
 #endif
 
@@ -547,7 +497,7 @@ void handle_unaligned(struct pt_regs *regs)
 		ret = emulate_stw(regs, R2(regs->iir),0);
 		break;
 
-#ifdef CONFIG_PA20
+#ifdef CONFIG_64BIT
 	case OPCODE_LDD_I:
 	case OPCODE_LDDA_I:
 	case OPCODE_LDD_S:
@@ -606,7 +556,7 @@ void handle_unaligned(struct pt_regs *regs)
 		flop=1;
 		ret = emulate_std(regs, R2(regs->iir),1);
 		break;
-#ifdef CONFIG_PA20
+#ifdef CONFIG_64BIT
 	case OPCODE_LDD_L:
 		ret = emulate_ldd(regs, R2(regs->iir),0);
 		break;
@@ -673,7 +623,7 @@ void handle_unaligned(struct pt_regs *regs)
 		printk(KERN_CRIT "Unaligned handler failed, ret = %d\n", ret);
 		die_if_kernel("Unaligned data reference", regs, 28);
 
-		if (ret == ERR_PAGEFAULT)
+		if (ret == -EFAULT)
 		{
 			force_sig_fault(SIGSEGV, SEGV_MAPERR,
 					(void __user *)regs->ior);