[PATCH] powerpc: Add ppc_inst_as_u64()

[Michael Ellerman]

The code patching code wants to get the value of a struct ppc_inst as
a u64 when the instruction is prefixed, so we can pass the u64 down to
__put_user_asm() and write it with a single store.

This is a bit awkward because the value differs based on the CPU
endianness, so add a helper to do the conversion.

Signed-off-by: Michael Ellerman <m...@ellerman.id.au>
---
 arch/powerpc/include/asm/inst.h  | 9 +++++++++
 arch/powerpc/kernel/optprobes.c  | 3 +--
 arch/powerpc/lib/code-patching.c | 8 +-------
 3 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/arch/powerpc/include/asm/inst.h b/arch/powerpc/include/asm/inst.h
index d82e0c99cfa1..d61e07fb2937 100644
--- a/arch/powerpc/include/asm/inst.h
+++ b/arch/powerpc/include/asm/inst.h
@@ -100,6 +100,15 @@ static inline int ppc_inst_len(struct ppc_inst x)
        return ppc_inst_prefixed(x) ? 8 : 4;
 }
 
+static inline u64 ppc_inst_as_u64(struct ppc_inst x)
+{
+#ifdef CONFIG_CPU_LITTLE_ENDIAN
+       return (u64)ppc_inst_suffix(x) << 32 | ppc_inst_val(x);
+#else
+       return (u64)ppc_inst_val(x) << 32 | ppc_inst_suffix(x);
+#endif
+}
+
 int probe_user_read_inst(struct ppc_inst *inst,
                         struct ppc_inst __user *nip);
 
diff --git a/arch/powerpc/kernel/optprobes.c b/arch/powerpc/kernel/optprobes.c
index 3ac105e7faae..69bfe96884e2 100644
--- a/arch/powerpc/kernel/optprobes.c
+++ b/arch/powerpc/kernel/optprobes.c
@@ -283,8 +283,7 @@ int arch_prepare_optimized_kprobe(struct optimized_kprobe 
*op, struct kprobe *p)
         * 3. load instruction to be emulated into relevant register, and
         */
        temp = ppc_inst_read((struct ppc_inst *)p->ainsn.insn);
-       patch_imm64_load_insns(ppc_inst_val(temp) | ((u64)ppc_inst_suffix(temp) 
<< 32),
-                              4, buff + TMPL_INSN_IDX);
+       patch_imm64_load_insns(ppc_inst_as_u64(temp), 4, buff + TMPL_INSN_IDX);
 
        /*
         * 4. branch back from trampoline
diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c
index 64cf621e5b00..5ecf0d635a8d 100644
--- a/arch/powerpc/lib/code-patching.c
+++ b/arch/powerpc/lib/code-patching.c
@@ -27,13 +27,7 @@ static int __patch_instruction(struct ppc_inst *exec_addr, 
struct ppc_inst instr
        if (!ppc_inst_prefixed(instr)) {
                __put_user_asm(ppc_inst_val(instr), patch_addr, err, "stw");
        } else {
-#ifdef CONFIG_CPU_LITTLE_ENDIAN
-               __put_user_asm((u64)ppc_inst_suffix(instr) << 32 |
-                              ppc_inst_val(instr), patch_addr, err, "std");
-#else
-               __put_user_asm((u64)ppc_inst_val(instr) << 32 |
-                              ppc_inst_suffix(instr), patch_addr, err, "std");
-#endif
+               __put_user_asm(ppc_inst_as_u64(instr), patch_addr, err, "std");
        }
 
        if (err)
-- 
2.25.1