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authorPaul Mackerras <paulus@ozlabs.org>2017-08-30 07:12:36 +0300
committerMichael Ellerman <mpe@ellerman.id.au>2017-09-01 09:39:54 +0300
commitb2543f7b20bb2a551ed340447d7303f0ce4644f1 (patch)
tree782ce4a44ad68bd1d372f0c77dd8542298b1deeb
parent1f41fb790460acf432f826f4aeeff6f7da891ff7 (diff)
downloadlinux-b2543f7b20bb2a551ed340447d7303f0ce4644f1.tar.xz
powerpc: Emulate the dcbz instruction
This adds code to analyse_instr() and emulate_step() to understand the dcbz (data cache block zero) instruction. The emulate_dcbz() function is made public so it can be used by the alignment handler in future. (The apparently unnecessary cropping of the address to 32 bits is there because it will be needed in that situation.) Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
-rw-r--r--arch/powerpc/include/asm/sstep.h2
-rw-r--r--arch/powerpc/lib/sstep.c32
2 files changed, 34 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/sstep.h b/arch/powerpc/include/asm/sstep.h
index 474a99255689..793639a5aa5e 100644
--- a/arch/powerpc/include/asm/sstep.h
+++ b/arch/powerpc/include/asm/sstep.h
@@ -84,6 +84,7 @@ enum instruction_type {
#define DCBTST 0x200
#define DCBT 0x300
#define ICBI 0x400
+#define DCBZ 0x500
/* VSX flags values */
#define VSX_FPCONV 1 /* do floating point SP/DP conversion */
@@ -155,3 +156,4 @@ extern void emulate_vsx_load(struct instruction_op *op, union vsx_reg *reg,
const void *mem);
extern void emulate_vsx_store(struct instruction_op *op, const union vsx_reg *reg,
void *mem);
+extern int emulate_dcbz(unsigned long ea, struct pt_regs *regs);
diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index 44a8ce062747..2d7e498b622b 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -780,6 +780,30 @@ static nokprobe_inline int do_vsx_store(struct instruction_op *op,
}
#endif /* CONFIG_VSX */
+int emulate_dcbz(unsigned long ea, struct pt_regs *regs)
+{
+ int err;
+ unsigned long i, size;
+
+#ifdef __powerpc64__
+ size = ppc64_caches.l1d.block_size;
+ if (!(regs->msr & MSR_64BIT))
+ ea &= 0xffffffffUL;
+#else
+ size = L1_CACHE_BYTES;
+#endif
+ ea &= ~(size - 1);
+ if (!address_ok(regs, ea, size))
+ return -EFAULT;
+ for (i = 0; i < size; i += sizeof(long)) {
+ err = __put_user(0, (unsigned long __user *) (ea + i));
+ if (err)
+ return err;
+ }
+ return 0;
+}
+NOKPROBE_SYMBOL(emulate_dcbz);
+
#define __put_user_asmx(x, addr, err, op, cr) \
__asm__ __volatile__( \
"1: " op " %2,0,%3\n" \
@@ -1748,6 +1772,11 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
op->type = MKOP(CACHEOP, ICBI, 0);
op->ea = xform_ea(instr, regs);
return 0;
+
+ case 1014: /* dcbz */
+ op->type = MKOP(CACHEOP, DCBZ, 0);
+ op->ea = xform_ea(instr, regs);
+ return 0;
}
break;
}
@@ -2607,6 +2636,9 @@ int emulate_step(struct pt_regs *regs, unsigned int instr)
case ICBI:
__cacheop_user_asmx(ea, err, "icbi");
break;
+ case DCBZ:
+ err = emulate_dcbz(ea, regs);
+ break;
}
if (err)
return 0;