Jordan Niethe's on March 20, 2020 3:17 pm:
> For modifying instructions in xmon, patch_instruction() can serve the
> same role that store_inst() is performing with the advantage of not
> being specific to xmon. In some places patch_instruction() is already
> being using followed by store_inst(). In these cases just remove the
> store_inst(). Otherwise replace store_inst() with patch_instruction().
LGTM
Reviewed-by: Nicholas Piggin <npig...@gmail.com>
>
> Signed-off-by: Jordan Niethe <jniet...@gmail.com>
> ---
> v4: Read into a local variable
> ---
> arch/powerpc/xmon/xmon.c | 18 +++++-------------
> 1 file changed, 5 insertions(+), 13 deletions(-)
>
> diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
> index e8c84d265602..02e3bd62cab4 100644
> --- a/arch/powerpc/xmon/xmon.c
> +++ b/arch/powerpc/xmon/xmon.c
> @@ -325,11 +325,6 @@ static inline void sync(void)
> asm volatile("sync; isync");
> }
>
> -static inline void store_inst(void *p)
> -{
> - asm volatile ("dcbst 0,%0; sync; icbi 0,%0; isync" : : "r" (p));
> -}
> -
> static inline void cflush(void *p)
> {
> asm volatile ("dcbf 0,%0; icbi 0,%0" : : "r" (p));
> @@ -881,8 +876,7 @@ 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[1] = bpinstr;
> - store_inst(&bp->instr[1]);
> + patch_instruction(&bp->instr[1], bpinstr);
> return bp;
> }
> }
> @@ -894,25 +888,26 @@ static struct bpt *new_breakpoint(unsigned long a)
> static void insert_bpts(void)
> {
> int i;
> + unsigned int instr;
> struct bpt *bp;
>
> bp = bpts;
> for (i = 0; i < NBPTS; ++i, ++bp) {
> if ((bp->enabled & (BP_TRAP|BP_CIABR)) == 0)
> continue;
> - if (mread(bp->address, &bp->instr[0], 4) != 4) {
> + if (mread(bp->address, &instr, 4) != 4) {
> printf("Couldn't read instruction at %lx, "
> "disabling breakpoint there\n", bp->address);
> bp->enabled = 0;
> continue;
> }
> - if (IS_MTMSRD(bp->instr[0]) || IS_RFID(bp->instr[0])) {
> + if (IS_MTMSRD(instr) || IS_RFID(instr)) {
> printf("Breakpoint at %lx is on an mtmsrd or rfid "
> "instruction, disabling it\n", bp->address);
> bp->enabled = 0;
> continue;
> }
> - store_inst(&bp->instr[0]);
> + patch_instruction(bp->instr, instr);
> if (bp->enabled & BP_CIABR)
> continue;
> if (patch_instruction((unsigned int *)bp->address,
> @@ -922,7 +917,6 @@ static void insert_bpts(void)
> bp->enabled &= ~BP_TRAP;
> continue;
> }
> - store_inst((void *)bp->address);
> }
> }
>
> @@ -957,8 +951,6 @@ static void remove_bpts(void)
> (unsigned int *)bp->address, bp->instr[0]) != 0)
> printf("Couldn't remove breakpoint at %lx\n",
> bp->address);
> - else
> - store_inst((void *)bp->address);
> }
> }
>
> --
> 2.17.1
>
>
