Messages in this thread | | | Date | Mon, 18 Apr 2022 13:08:44 +0530 | From | "Naveen N. Rao" <> | Subject | Re: [PATCH v1 13/22] powerpc/ftrace: Use PPC_RAW_xxx() macros instead of opencoding. |
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Christophe Leroy wrote: > PPC_RAW_xxx() macros are self explanatory and less error prone > than open coding. > > Use them in ftrace.c > > Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> > --- > arch/powerpc/include/asm/ppc-opcode.h | 3 +++ > arch/powerpc/kernel/trace/ftrace.c | 32 +++++++++------------------ > 2 files changed, 14 insertions(+), 21 deletions(-) > > diff --git a/arch/powerpc/include/asm/ppc-opcode.h b/arch/powerpc/include/asm/ppc-opcode.h > index 82f1f0041c6f..281754aca0a3 100644 > --- a/arch/powerpc/include/asm/ppc-opcode.h > +++ b/arch/powerpc/include/asm/ppc-opcode.h > @@ -294,6 +294,8 @@ > #define PPC_INST_BL 0x48000001 > #define PPC_INST_BRANCH_COND 0x40800000 > > +#define PPC_INST_OFFSET24_MASK 0x03fffffc
This corresponds to the LI field, per the ISA. See section 8.1.2/1.7: 'Instruction Fields'. Would it be better to name it PPC_INST_LI_MASK?
> + > /* Prefixes */ > #define PPC_INST_LFS 0xc0000000 > #define PPC_INST_STFS 0xd0000000 > @@ -572,6 +574,7 @@ > #define PPC_RAW_EIEIO() (0x7c0006ac) > > #define PPC_RAW_BRANCH(addr) (PPC_INST_BRANCH | ((addr) & 0x03fffffc)) > +#define PPC_RAW_BL(offset) (0x48000001 | ((offset) & PPC_INST_OFFSET24_MASK)) > > /* Deal with instructions that older assemblers aren't aware of */ > #define PPC_BCCTR_FLUSH stringify_in_c(.long PPC_INST_BCCTR_FLUSH) > diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c > index fdc0412c1d8a..afb1d12838c9 100644 > --- a/arch/powerpc/kernel/trace/ftrace.c > +++ b/arch/powerpc/kernel/trace/ftrace.c > @@ -90,19 +90,19 @@ static int test_24bit_addr(unsigned long ip, unsigned long addr) > > static int is_bl_op(ppc_inst_t op) > { > - return (ppc_inst_val(op) & 0xfc000003) == 0x48000001; > + return (ppc_inst_val(op) & ~PPC_INST_OFFSET24_MASK) == PPC_RAW_BL(0); > } > > static int is_b_op(ppc_inst_t op) > { > - return (ppc_inst_val(op) & 0xfc000003) == 0x48000000; > + return (ppc_inst_val(op) & ~PPC_INST_OFFSET24_MASK) == PPC_RAW_BRANCH(0); > } > > static unsigned long find_bl_target(unsigned long ip, ppc_inst_t op) > { > int offset; > > - offset = (ppc_inst_val(op) & 0x03fffffc); > + offset = (ppc_inst_val(op) & PPC_INST_OFFSET24_MASK); > /* make it signed */ > if (offset & 0x02000000) > offset |= 0xfe000000; > @@ -182,7 +182,7 @@ __ftrace_make_nop(struct module *mod, > * Use a b +8 to jump over the load. > */ > > - pop = ppc_inst(PPC_INST_BRANCH | 8); /* b +8 */ > + pop = ppc_inst(PPC_RAW_BRANCH(8)); /* b +8 */ > > /* > * Check what is in the next instruction. We can see ld r2,40(r1), but > @@ -394,17 +394,8 @@ int ftrace_make_nop(struct module *mod, > static int > expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1) > { > - /* > - * We expect to see: > - * > - * b +8 > - * ld r2,XX(r1) > - * > - * The load offset is different depending on the ABI. For simplicity > - * just mask it out when doing the compare. > - */ > - if (!ppc_inst_equal(op0, ppc_inst(0x48000008)) || > - (ppc_inst_val(op1) & 0xffff0000) != 0xe8410000) > + if (!ppc_inst_equal(op0, ppc_inst(PPC_RAW_BRANCH(8))) || > + !ppc_inst_equal(op1, ppc_inst(PPC_INST_LD_TOC)))
It would be good to move PPC_INST_LD_TOC to ppc-opcode.h
> return 0; > return 1; > } > @@ -412,7 +403,6 @@ expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1) > static int > expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1) > { > - /* look for patched "NOP" on ppc64 with -mprofile-kernel or ppc32 */ > if (!ppc_inst_equal(op0, ppc_inst(PPC_RAW_NOP()))) > return 0; > return 1; > @@ -738,11 +728,11 @@ int __init ftrace_dyn_arch_init(void) > int i; > unsigned int *tramp[] = { ftrace_tramp_text, ftrace_tramp_init }; > 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_RAW_LD(_R12, _R13, PACATOC), > + PPC_RAW_ADDIS(_R12, _R12, 0), > + PPC_RAW_ADDIS(_R12, _R12, 0),
This should be PPC_RAW_ADDI.
- Naveen
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