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Subject[PATCH v3 3/3] powerpc/module64: Use symbolic instructions names.
Date
To increase readability/maintainability, replace hard coded
instructions values by symbolic names.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
v3: fixed warning by adding () in an 'if' around X | Y (unlike said in v2 history, this change was forgotten in v2)
v2: rearranged comments

arch/powerpc/kernel/module_64.c | 53 +++++++++++++++++++++++++++--------------
1 file changed, 35 insertions(+), 18 deletions(-)

diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
index c2e1b06253b8..b33a5d5e2d35 100644
--- a/arch/powerpc/kernel/module_64.c
+++ b/arch/powerpc/kernel/module_64.c
@@ -133,20 +133,27 @@ struct ppc64_stub_entry
* the stub, but it's significantly shorter to put these values at the
* end of the stub code, and patch the stub address (32-bits relative
* to the TOC ptr, r2) into the stub.
+ *
+ * addis r11,r2, <high>
+ * addi r11,r11, <low>
+ * std r2,R2_STACK_OFFSET(r1)
+ * ld r12,32(r11)
+ * ld r2,40(r11)
+ * mtctr r12
+ * bctr
*/
-
static u32 ppc64_stub_insns[] = {
- 0x3d620000, /* addis r11,r2, <high> */
- 0x396b0000, /* addi r11,r11, <low> */
+ PPC_INST_ADDIS | __PPC_RT(R11) | __PPC_RA(R2),
+ PPC_INST_ADDI | __PPC_RT(R11) | __PPC_RA(R11),
/* Save current r2 value in magic place on the stack. */
- 0xf8410000|R2_STACK_OFFSET, /* std r2,R2_STACK_OFFSET(r1) */
- 0xe98b0020, /* ld r12,32(r11) */
+ PPC_INST_STD | __PPC_RS(R2) | __PPC_RA(R1) | R2_STACK_OFFSET,
+ PPC_INST_LD | __PPC_RT(R12) | __PPC_RA(R11) | 32,
#ifdef PPC64_ELF_ABI_v1
/* Set up new r2 from function descriptor */
- 0xe84b0028, /* ld r2,40(r11) */
+ PPC_INST_LD | __PPC_RT(R2) | __PPC_RA(R11) | 40,
#endif
- 0x7d8903a6, /* mtctr r12 */
- 0x4e800420 /* bctr */
+ PPC_INST_MTCTR | __PPC_RS(R12),
+ PPC_INST_BCTR,
};

#ifdef CONFIG_DYNAMIC_FTRACE
@@ -704,18 +711,21 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
* ld r2, ...(r12)
* add r2, r2, r12
*/
- if ((((uint32_t *)location)[0] & ~0xfffc)
- != 0xe84c0000)
+ if ((((uint32_t *)location)[0] & ~0xfffc) !=
+ (PPC_INST_LD | __PPC_RT(R2) | __PPC_RA(R12)))
break;
- if (((uint32_t *)location)[1] != 0x7c426214)
+ if (((uint32_t *)location)[1] !=
+ (PPC_INST_ADD | __PPC_RT(R2) | __PPC_RA(R2) | __PPC_RB(R12)))
break;
/*
* If found, replace it with:
* addis r2, r12, (.TOC.-func)@ha
* addi r2, r12, (.TOC.-func)@l
*/
- ((uint32_t *)location)[0] = 0x3c4c0000 + PPC_HA(value);
- ((uint32_t *)location)[1] = 0x38420000 + PPC_LO(value);
+ ((uint32_t *)location)[0] = PPC_INST_ADDIS | __PPC_RT(R2) |
+ __PPC_RA(R12) | PPC_HA(value);
+ ((uint32_t *)location)[1] = PPC_INST_ADDI | __PPC_RT(R2) |
+ __PPC_RA(R12) | PPC_LO(value);
break;

case R_PPC64_REL16_HA:
@@ -769,12 +779,19 @@ static unsigned long create_ftrace_stub(const Elf64_Shdr *sechdrs,
{
struct ppc64_stub_entry *entry;
unsigned int i, num_stubs;
+ /*
+ * ld r12,PACATOC(r13)
+ * addis r12,r12,<high>
+ * addi r12,r12,<low>
+ * mtctr r12
+ * bctr
+ */
static u32 stub_insns[] = {
- 0xe98d0000 | PACATOC, /* ld r12,PACATOC(r13) */
- 0x3d8c0000, /* addis r12,r12,<high> */
- 0x398c0000, /* addi r12,r12,<low> */
- 0x7d8903a6, /* mtctr r12 */
- 0x4e800420, /* bctr */
+ PPC_INST_LD | __PPC_RT(R12) | __PPC_RA(R13) | PACATOC,
+ PPC_INST_ADDIS | __PPC_RT(R12) | __PPC_RA(R12),
+ PPC_INST_ADDI | __PPC_RT(R12) | __PPC_RA(R12),
+ PPC_INST_MTCTR | __PPC_RS(R12),
+ PPC_INST_BCTR,
};
long reladdr;

--
2.13.3
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