Date: Sat, 8 Jun 2024 12:38:08 +0530
From: Athira Rajeev <atrajeev@...ux.vnet.ibm.com>
To: Namhyung Kim <namhyung@...nel.org>
Cc: Arnaldo Carvalho de Melo <acme@...nel.org>, Jiri Olsa <jolsa@...nel.org>,
        Adrian Hunter <adrian.hunter@...el.com>,
        Ian Rogers <irogers@...gle.com>,
        Segher Boessenkool <segher@...nel.crashing.org>,
        christophe.leroy@...roup.eu, linux-kernel@...r.kernel.org,
        linux-perf-users@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org,
        akanksha@...ux.ibm.com, maddy@...ux.ibm.com, kjain@...ux.ibm.com,
        disgoel@...ux.vnet.ibm.com
Subject: Re: [PATCH V3 06/14] tools/perf: Update parameters for reg extract
 functions to use raw instruction on powerpc



> On 6 Jun 2024, at 12:22 PM, Namhyung Kim <namhyung@...nel.org> wrote:
> 
> On Sat, Jun 01, 2024 at 11:39:33AM +0530, Athira Rajeev wrote:
>> Use the raw instruction code and macros to identify memory instructions,
>> extract register fields and also offset. The implementation addresses
>> the D-form, X-form, DS-form instructions. Two main functions are added.
>> New parse function "load_store__parse" as instruction ops parser for
>> memory instructions. Unlink other parser (like mov__parse), this parser
>> fills in the "raw_insn" field for source/target and new added "mem_ref"
>> field. Also set if it is multi_regs and opcode as well. No other fields
>> are set because, here there is no need to parse the disassembled
>> code and arch specific macros will take care of extracting offset and
>> regs which is easier and will be precise.
>> 
>> In powerpc, all instructions with a primary opcode from 32 to 63
>> are memory instructions. Update "ins__find" function to have "raw_insn"
>> also as a parameter. Don't use the "extract_reg_offset", instead use
>> newly added function "get_arch_regs" which will set these fields: reg1,
>> reg2, offset depending of where it is source or target ops.
>> 
>> Signed-off-by: Athira Rajeev <atrajeev@...ux.vnet.ibm.com>
>> ---
>> .../perf/arch/powerpc/annotate/instructions.c | 16 +++++
>> tools/perf/arch/powerpc/util/dwarf-regs.c     | 44 +++++++++++++
>> tools/perf/util/annotate.c                    | 25 +++++++-
>> tools/perf/util/disasm.c                      | 64 +++++++++++++++++--
>> tools/perf/util/disasm.h                      |  4 +-
>> tools/perf/util/include/dwarf-regs.h          |  3 +
>> 6 files changed, 147 insertions(+), 9 deletions(-)
>> 
>> diff --git a/tools/perf/arch/powerpc/annotate/instructions.c b/tools/perf/arch/powerpc/annotate/instructions.c
>> index d57fd023ef9c..10fea5e5cf4c 100644
>> --- a/tools/perf/arch/powerpc/annotate/instructions.c
>> +++ b/tools/perf/arch/powerpc/annotate/instructions.c
>> @@ -49,6 +49,22 @@ static struct ins_ops *powerpc__associate_instruction_ops(struct arch *arch, con
>> return ops;
>> }
>> 
>> +#define PPC_OP(op)      (((op) >> 26) & 0x3F)
>> +
>> +static struct ins_ops *check_ppc_insn(int raw_insn)
>> +{
>> + int opcode = PPC_OP(raw_insn);
>> +
>> + /*
>> +  * Instructions with opcode 32 to 63 are memory
>> +  * instructions in powerpc
>> +  */
>> + if ((opcode & 0x20))
>> + return &load_store_ops;
>> +
>> + return NULL;
>> +}
>> +
>> static int powerpc__annotate_init(struct arch *arch, char *cpuid __maybe_unused)
>> {
>> if (!arch->initialized) {
>> diff --git a/tools/perf/arch/powerpc/util/dwarf-regs.c b/tools/perf/arch/powerpc/util/dwarf-regs.c
>> index 430623ca5612..38b74fa01d8b 100644
>> --- a/tools/perf/arch/powerpc/util/dwarf-regs.c
>> +++ b/tools/perf/arch/powerpc/util/dwarf-regs.c
>> @@ -107,3 +107,47 @@ int regs_query_register_offset(const char *name)
>> #define PPC_DS(DS) ((DS) & 0xfffc)
>> #define OP_LD 58
>> #define OP_STD 62
>> +
>> +static int get_source_reg(unsigned int raw_insn)
>> +{
>> + return PPC_RA(raw_insn);
>> +}
>> +
>> +static int get_target_reg(unsigned int raw_insn)
>> +{
>> + return PPC_RT(raw_insn);
>> +}
>> +
>> +static int get_offset_opcode(int raw_insn __maybe_unused)
> 
> The argument is used below, no need for __maybe_unused.
> 
>> +{
>> + int opcode = PPC_OP(raw_insn);
>> +
>> + /* DS- form */
>> + if ((opcode == OP_LD) || (opcode == OP_STD))
>> + return PPC_DS(raw_insn);
>> + else
>> + return PPC_D(raw_insn);
>> +}
>> +
>> +/*
>> + * Fills the required fields for op_loc depending on if it
>> + * is a source or target.
>> + * D form: ins RT,D(RA) -> src_reg1 = RA, offset = D, dst_reg1 = RT
>> + * DS form: ins RT,DS(RA) -> src_reg1 = RA, offset = DS, dst_reg1 = RT
>> + * X form: ins RT,RA,RB -> src_reg1 = RA, src_reg2 = RB, dst_reg1 = RT
>> + */
>> +void get_arch_regs(int raw_insn __maybe_unused, int is_source __maybe_unused,
>> + struct annotated_op_loc *op_loc __maybe_unused)
> 
> Ditto.

Yes, right. Will fix it both the places.

Thanks
Athira
> 
> Thanks,
> Namhyung

> 
> 
>> +{
>> + if (is_source)
>> + op_loc->reg1 = get_source_reg(raw_insn);
>> + else
>> + op_loc->reg1 = get_target_reg(raw_insn);
>> +
>> + if (op_loc->multi_regs)
>> + op_loc->reg2 = PPC_RB(raw_insn);
>> +
>> + /* TODO: Implement offset handling for X Form */
>> + if ((op_loc->mem_ref) && (PPC_OP(raw_insn) != 31))
>> + op_loc->offset = get_offset_opcode(raw_insn);
>> +}
>> diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
>> index 1451caf25e77..2b8cc759ae35 100644
>> --- a/tools/perf/util/annotate.c
>> +++ b/tools/perf/util/annotate.c
>> @@ -2079,6 +2079,12 @@ static int extract_reg_offset(struct arch *arch, const char *str,
>> return 0;
>> }
>> 
>> +__weak void get_arch_regs(int raw_insn __maybe_unused, int is_source __maybe_unused,
>> + struct annotated_op_loc *op_loc __maybe_unused)
>> +{
>> + return;
>> +}
>> +
>> /**
>>  * annotate_get_insn_location - Get location of instruction
>>  * @arch: the architecture info
>> @@ -2123,20 +2129,33 @@ int annotate_get_insn_location(struct arch *arch, struct disasm_line *dl,
>> for_each_insn_op_loc(loc, i, op_loc) {
>> const char *insn_str = ops->source.raw;
>> bool multi_regs = ops->source.multi_regs;
>> + bool mem_ref = ops->source.mem_ref;
>> 
>> if (i == INSN_OP_TARGET) {
>> insn_str = ops->target.raw;
>> multi_regs = ops->target.multi_regs;
>> + mem_ref = ops->target.mem_ref;
>> }
>> 
>> /* Invalidate the register by default */
>> op_loc->reg1 = -1;
>> op_loc->reg2 = -1;
>> 
>> - if (insn_str == NULL)
>> - continue;
>> + if (insn_str == NULL) {
>> + if (!arch__is(arch, "powerpc"))
>> + continue;
>> + }
>> 
>> - if (strchr(insn_str, arch->objdump.memory_ref_char)) {
>> + /*
>> +  * For powerpc, call get_arch_regs function which extracts the
>> +  * required fields for op_loc, ie reg1, reg2, offset from the
>> +  * raw instruction.
>> +  */
>> + if (arch__is(arch, "powerpc")) {
>> + op_loc->mem_ref = mem_ref;
>> + op_loc->multi_regs = multi_regs;
>> + get_arch_regs(ops->raw_insn, !i, op_loc);
>> + } else if (strchr(insn_str, arch->objdump.memory_ref_char)) {
>> op_loc->mem_ref = true;
>> op_loc->multi_regs = multi_regs;
>> extract_reg_offset(arch, insn_str, op_loc);
>> diff --git a/tools/perf/util/disasm.c b/tools/perf/util/disasm.c
>> index 61f0f1656f82..252cb0d1f5d1 100644
>> --- a/tools/perf/util/disasm.c
>> +++ b/tools/perf/util/disasm.c
>> @@ -37,6 +37,7 @@ static struct ins_ops mov_ops;
>> static struct ins_ops nop_ops;
>> static struct ins_ops lock_ops;
>> static struct ins_ops ret_ops;
>> +static struct ins_ops load_store_ops;
>> 
>> static int jump__scnprintf(struct ins *ins, char *bf, size_t size,
>>    struct ins_operands *ops, int max_ins_name);
>> @@ -517,7 +518,7 @@ static int lock__parse(struct arch *arch, struct ins_operands *ops, struct map_s
>> if (disasm_line__parse(ops->raw, &ops->locked.ins.name, &ops->locked.ops->raw) < 0)
>> goto out_free_ops;
>> 
>> - ops->locked.ins.ops = ins__find(arch, ops->locked.ins.name);
>> + ops->locked.ins.ops = ins__find(arch, ops->locked.ins.name, 0);
>> 
>> if (ops->locked.ins.ops == NULL)
>> goto out_free_ops;
>> @@ -672,6 +673,47 @@ static struct ins_ops mov_ops = {
>> .scnprintf = mov__scnprintf,
>> };
>> 
>> +static int load_store__scnprintf(struct ins *ins, char *bf, size_t size,
>> + struct ins_operands *ops, int max_ins_name)
>> +{
>> + return scnprintf(bf, size, "%-*s %s", max_ins_name, ins->name,
>> + ops->raw);
>> +}
>> +
>> +/*
>> + * Sets the fields: "raw_insn", opcode, multi_regs and "mem_ref".
>> + * "mem_ref" is set for ops->source which is later used to
>> + * fill the objdump->memory_ref-char field. This ops is currently
>> + * used by powerpc and since binary instruction code is used to
>> + * extract opcode, regs and offset, no other parsing is needed here
>> + */
>> +static int load_store__parse(struct arch *arch __maybe_unused, struct ins_operands *ops,
>> + struct map_symbol *ms __maybe_unused)
>> +{
>> + ops->source.raw_insn = ops->raw_insn;
>> + ops->source.mem_ref = true;
>> + ops->source.opcode = ops->opcode;
>> + ops->source.multi_regs = false;
>> +
>> + if (!ops->source.raw_insn)
>> + return -1;
>> +
>> + ops->target.raw_insn = ops->raw_insn;
>> + ops->target.mem_ref = false;
>> + ops->target.multi_regs = false;
>> + ops->target.opcode = ops->opcode;
>> +
>> + if (!ops->target.raw_insn)
>> + return -1;
>> +
>> + return 0;
>> +}
>> +
>> +static struct ins_ops load_store_ops = {
>> + .parse     = load_store__parse,
>> + .scnprintf = load_store__scnprintf,
>> +};
>> +
>> static int dec__parse(struct arch *arch __maybe_unused, struct ins_operands *ops, struct map_symbol *ms __maybe_unused)
>> {
>> char *target, *comment, *s, prev;
>> @@ -762,11 +804,23 @@ static void ins__sort(struct arch *arch)
>> qsort(arch->instructions, nmemb, sizeof(struct ins), ins__cmp);
>> }
>> 
>> -static struct ins_ops *__ins__find(struct arch *arch, const char *name)
>> +static struct ins_ops *__ins__find(struct arch *arch, const char *name, int raw_insn)
>> {
>> struct ins *ins;
>> const int nmemb = arch->nr_instructions;
>> 
>> + if (arch__is(arch, "powerpc")) {
>> + /*
>> +  * For powerpc, identify the instruction ops
>> +  * from the opcode using raw_insn.
>> +  */
>> + struct ins_ops *ops;
>> +
>> + ops = check_ppc_insn(raw_insn);
>> + if (ops)
>> + return ops;
>> + }
>> +
>> if (!arch->sorted_instructions) {
>> ins__sort(arch);
>> arch->sorted_instructions = true;
>> @@ -796,9 +850,9 @@ static struct ins_ops *__ins__find(struct arch *arch, const char *name)
>> return ins ? ins->ops : NULL;
>> }
>> 
>> -struct ins_ops *ins__find(struct arch *arch, const char *name)
>> +struct ins_ops *ins__find(struct arch *arch, const char *name, int raw_insn)
>> {
>> - struct ins_ops *ops = __ins__find(arch, name);
>> + struct ins_ops *ops = __ins__find(arch, name, raw_insn);
>> 
>> if (!ops && arch->associate_instruction_ops)
>> ops = arch->associate_instruction_ops(arch, name);
>> @@ -808,7 +862,7 @@ struct ins_ops *ins__find(struct arch *arch, const char *name)
>> 
>> static void disasm_line__init_ins(struct disasm_line *dl, struct arch *arch, struct map_symbol *ms)
>> {
>> - dl->ins.ops = ins__find(arch, dl->ins.name);
>> + dl->ins.ops = ins__find(arch, dl->ins.name, dl->ops.raw_insn);
>> 
>> if (!dl->ins.ops)
>> return;
>> diff --git a/tools/perf/util/disasm.h b/tools/perf/util/disasm.h
>> index a391e1bb81f7..831ebcc329cd 100644
>> --- a/tools/perf/util/disasm.h
>> +++ b/tools/perf/util/disasm.h
>> @@ -62,6 +62,7 @@ struct ins_operands {
>> bool offset_avail;
>> bool outside;
>> bool multi_regs;
>> + bool mem_ref;
>> } target;
>> union {
>> struct {
>> @@ -71,6 +72,7 @@ struct ins_operands {
>> int raw_insn;
>> u64 addr;
>> bool multi_regs;
>> + bool mem_ref;
>> } source;
>> struct {
>> struct ins     ins;
>> @@ -104,7 +106,7 @@ struct annotate_args {
>> struct arch *arch__find(const char *name);
>> bool arch__is(struct arch *arch, const char *name);
>> 
>> -struct ins_ops *ins__find(struct arch *arch, const char *name);
>> +struct ins_ops *ins__find(struct arch *arch, const char *name, int raw_insn);
>> int ins__scnprintf(struct ins *ins, char *bf, size_t size,
>>    struct ins_operands *ops, int max_ins_name);
>> 
>> diff --git a/tools/perf/util/include/dwarf-regs.h b/tools/perf/util/include/dwarf-regs.h
>> index 01fb25a1150a..7ea39362ecaf 100644
>> --- a/tools/perf/util/include/dwarf-regs.h
>> +++ b/tools/perf/util/include/dwarf-regs.h
>> @@ -1,6 +1,7 @@
>> /* SPDX-License-Identifier: GPL-2.0 */
>> #ifndef _PERF_DWARF_REGS_H_
>> #define _PERF_DWARF_REGS_H_
>> +#include "annotate.h"
>> 
>> #define DWARF_REG_PC  0xd3af9c /* random number */
>> #define DWARF_REG_FB  0xd3affb /* random number */
>> @@ -31,6 +32,8 @@ static inline int get_dwarf_regnum(const char *name __maybe_unused,
>> }
>> #endif
>> 
>> +void get_arch_regs(int raw_insn, int is_source, struct annotated_op_loc *op_loc);
>> +
>> #ifdef HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET
>> /*
>>  * Arch should support fetching the offset of a register in pt_regs
>> -- 
>> 2.43.0

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