Shouldn't change anything and will be correct once prefix instructions are
defined.
Reviewed-by: Alistair Popple <alist...@popple.id.au>
On Friday, 1 May 2020 1:42:10 PM AEST Jordan Niethe wrote:
> Currently in xmon, mread() is used for reading instructions. In
> preparation for prefixed instructions, create and use a new function,
> mread_instr(), especially for reading instructions.
>
> Signed-off-by: Jordan Niethe <jniet...@gmail.com>
> ---
> v5: New to series, seperated from "Add prefixed instructions to
> instruction data type"
> v6: mread_instr(): correctly return error status
> ---
> arch/powerpc/xmon/xmon.c | 28 ++++++++++++++++++++++++----
> 1 file changed, 24 insertions(+), 4 deletions(-)
>
> diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
> index cde733a82366..1947821e425d 100644
> --- a/arch/powerpc/xmon/xmon.c
> +++ b/arch/powerpc/xmon/xmon.c
> @@ -122,6 +122,7 @@ static unsigned bpinstr = 0x7fe00008; /* trap */
> static int cmds(struct pt_regs *);
> static int mread(unsigned long, void *, int);
> static int mwrite(unsigned long, void *, int);
> +static int mread_instr(unsigned long, struct ppc_inst *);
> static int handle_fault(struct pt_regs *);
> static void byterev(unsigned char *, int);
> static void memex(void);
> @@ -896,7 +897,7 @@ static void insert_bpts(void)
> for (i = 0; i < NBPTS; ++i, ++bp) {
> if ((bp->enabled & (BP_TRAP|BP_CIABR)) == 0)
> continue;
> - if (mread(bp->address, &instr, 4) != 4) {
> + if (!mread_instr(bp->address, &instr)) {
> printf("Couldn't read instruction at %lx, "
> "disabling breakpoint there\n", bp->address);
> bp->enabled = 0;
> @@ -946,7 +947,7 @@ static void remove_bpts(void)
> for (i = 0; i < NBPTS; ++i, ++bp) {
> if ((bp->enabled & (BP_TRAP|BP_CIABR)) != BP_TRAP)
> continue;
> - if (mread(bp->address, &instr, 4) == 4
> + if (mread_instr(bp->address, &instr)
> && ppc_inst_equal(instr, ppc_inst(bpinstr))
> && patch_instruction(
> (struct ppc_inst *)bp->address,
> ppc_inst_read(bp->instr)) != 0)
> @@ -1162,7 +1163,7 @@ static int do_step(struct pt_regs *regs)
> force_enable_xmon();
> /* check we are in 64-bit kernel mode, translation enabled */
> if ((regs->msr & (MSR_64BIT|MSR_PR|MSR_IR)) == (MSR_64BIT|MSR_IR)) {
> - if (mread(regs->nip, &instr, 4) == 4) {
> + if (mread_instr(regs->nip, &instr)) {
> stepped = emulate_step(regs, instr);
> if (stepped < 0) {
> printf("Couldn't single-step %s instruction\n",
> @@ -1329,7 +1330,7 @@ static long check_bp_loc(unsigned long addr)
> printf("Breakpoints may only be placed at kernel addresses\n");
> return 0;
> }
> - if (!mread(addr, &instr, sizeof(instr))) {
> + if (!mread_instr(addr, &instr)) {
> printf("Can't read instruction at address %lx\n", addr);
> return 0;
> }
> @@ -2122,6 +2123,25 @@ mwrite(unsigned long adrs, void *buf, int size)
> return n;
> }
>
> +static int
> +mread_instr(unsigned long adrs, struct ppc_inst *instr)
> +{
> + volatile int n;
> +
> + n = 0;
> + if (setjmp(bus_error_jmp) == 0) {
> + catch_memory_errors = 1;
> + sync();
> + *instr = ppc_inst_read((struct ppc_inst *)adrs);
> + sync();
> + /* wait a little while to see if we get a machine check */
> + __delay(200);
> + n = ppc_inst_len(*instr);
> + }
> + catch_memory_errors = 0;
> + return n;
> +}
> +
> static int fault_type;
> static int fault_except;
> static char *fault_chars[] = { "--", "**", "##" };
