From 94afd069d937d84fb4f696eb9a78db4084e43d21 Mon Sep 17 00:00:00 2001
From: Jordan Niethe <jniethe5@gmail.com>
Date: Wed, 6 May 2020 13:40:31 +1000
Subject: powerpc: Use a datatype for instructions

Currently unsigned ints are used to represent instructions on powerpc.
This has worked well as instructions have always been 4 byte words.

However, ISA v3.1 introduces some changes to instructions that mean
this scheme will no longer work as well. This change is Prefixed
Instructions. A prefixed instruction is made up of a word prefix
followed by a word suffix to make an 8 byte double word instruction.
No matter the endianness of the system the prefix always comes first.
Prefixed instructions are only planned for powerpc64.

Introduce a ppc_inst type to represent both prefixed and word
instructions on powerpc64 while keeping it possible to exclusively
have word instructions on powerpc32.

Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
[mpe: Fix compile error in emulate_spe()]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200506034050.24806-12-jniethe5@gmail.com
---
 arch/powerpc/xmon/xmon.c      | 22 +++++++++++-----------
 arch/powerpc/xmon/xmon_bpts.h |  6 +++---
 2 files changed, 14 insertions(+), 14 deletions(-)

(limited to 'arch/powerpc/xmon')

diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index 4cf998518047..2e3b15813cf1 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -100,7 +100,7 @@ static long *xmon_fault_jmp[NR_CPUS];
 /* Breakpoint stuff */
 struct bpt {
 	unsigned long	address;
-	unsigned int	*instr;
+	struct ppc_inst	*instr;
 	atomic_t	ref_count;
 	int		enabled;
 	unsigned long	pad;
@@ -876,8 +876,8 @@ static struct bpt *new_breakpoint(unsigned long a)
 	for (bp = bpts; bp < &bpts[NBPTS]; ++bp) {
 		if (!bp->enabled && atomic_read(&bp->ref_count) == 0) {
 			bp->address = a;
-			bp->instr = bpt_table + ((bp - bpts) * BPT_WORDS);
-			patch_instruction(bp->instr + 1, bpinstr);
+			bp->instr = (void *)(bpt_table + ((bp - bpts) * BPT_WORDS));
+			patch_instruction(bp->instr + 1, ppc_inst(bpinstr));
 			return bp;
 		}
 	}
@@ -889,7 +889,7 @@ static struct bpt *new_breakpoint(unsigned long a)
 static void insert_bpts(void)
 {
 	int i;
-	unsigned int instr;
+	struct ppc_inst instr;
 	struct bpt *bp;
 
 	bp = bpts;
@@ -911,8 +911,8 @@ static void insert_bpts(void)
 		patch_instruction(bp->instr, instr);
 		if (bp->enabled & BP_CIABR)
 			continue;
-		if (patch_instruction((unsigned int *)bp->address,
-							bpinstr) != 0) {
+		if (patch_instruction((struct ppc_inst *)bp->address,
+				      ppc_inst(bpinstr)) != 0) {
 			printf("Couldn't write instruction at %lx, "
 			       "disabling breakpoint there\n", bp->address);
 			bp->enabled &= ~BP_TRAP;
@@ -940,7 +940,7 @@ static void remove_bpts(void)
 {
 	int i;
 	struct bpt *bp;
-	unsigned instr;
+	struct ppc_inst instr;
 
 	bp = bpts;
 	for (i = 0; i < NBPTS; ++i, ++bp) {
@@ -949,7 +949,7 @@ static void remove_bpts(void)
 		if (mread(bp->address, &instr, 4) == 4
 		    && ppc_inst_equal(instr, ppc_inst(bpinstr))
 		    && patch_instruction(
-			(unsigned int *)bp->address, bp->instr[0]) != 0)
+			(struct ppc_inst *)bp->address, bp->instr[0]) != 0)
 			printf("Couldn't remove breakpoint at %lx\n",
 			       bp->address);
 	}
@@ -1156,7 +1156,7 @@ static int do_step(struct pt_regs *regs)
  */
 static int do_step(struct pt_regs *regs)
 {
-	unsigned int instr;
+	struct ppc_inst instr;
 	int stepped;
 
 	force_enable_xmon();
@@ -1322,7 +1322,7 @@ csum(void)
  */
 static long check_bp_loc(unsigned long addr)
 {
-	unsigned int instr;
+	struct ppc_inst instr;
 
 	addr &= ~3;
 	if (!is_kernel_addr(addr)) {
@@ -2848,7 +2848,7 @@ generic_inst_dump(unsigned long adr, long count, int praddr,
 {
 	int nr, dotted;
 	unsigned long first_adr;
-	unsigned int inst, last_inst = ppc_inst(0);
+	struct ppc_inst inst, last_inst = ppc_inst(0);
 	unsigned char val[4];
 
 	dotted = 0;
diff --git a/arch/powerpc/xmon/xmon_bpts.h b/arch/powerpc/xmon/xmon_bpts.h
index b7e94375db86..57e6fb03de48 100644
--- a/arch/powerpc/xmon/xmon_bpts.h
+++ b/arch/powerpc/xmon/xmon_bpts.h
@@ -4,11 +4,11 @@
 
 #define NBPTS	256
 #ifndef __ASSEMBLY__
-#define BPT_SIZE	(sizeof(unsigned int) * 2)
-#define BPT_WORDS	(BPT_SIZE / sizeof(unsigned int))
+#include <asm/inst.h>
+#define BPT_SIZE	(sizeof(struct ppc_inst) * 2)
+#define BPT_WORDS	(BPT_SIZE / sizeof(struct ppc_inst))
 
 extern unsigned int bpt_table[NBPTS * BPT_WORDS];
-
 #endif /* __ASSEMBLY__ */
 
 #endif /* XMON_BPTS_H */
-- 
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