The current code uses macros PERF_REG_IP and PERF_REG_SP for parsing registers and we build perf with these macros statically, which means it only can correctly analyze CPU registers for the native architecture and fails to support cross analysis (e.g. we build perf on x86 and cannot analyze Arm64's registers). We need to generalize util/perf_regs.c for support multi architectures, as a first step, this commit introduces new functions perf_arch_reg_ip() and perf_arch_reg_sp(), these two functions dynamically return IP and SP register index respectively according to the parameter "arch". Every architecture has its own functions (like __perf_reg_ip_arm64 and __perf_reg_sp_arm64), these architecture specific functions are defined in each arch source file under folder util/perf-regs-arch; at the end all of them are built into the tool for cross analysis. Committer notes: Make DWARF_MINIMAL_REGS() an inline function, so that we can use the __maybe_unused attribute for the 'arch' parameter, as this will avoid a build failure when that variable is unused in the callers. That happens when building on unsupported architectures, the ones without HAVE_PERF_REGS_SUPPORT defined. Signed-off-by: Leo Yan <leo.yan@linaro.org> Acked-by: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Eric Lin <eric.lin@sifive.com> Cc: Fangrui Song <maskray@google.com> Cc: Guo Ren <guoren@kernel.org> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ivan Babrou <ivan@cloudflare.com> Cc: James Clark <james.clark@arm.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Garry <john.g.garry@oracle.com> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mike Leach <mike.leach@linaro.org> Cc: Ming Wang <wangming01@loongson.cn> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sandipan Das <sandipan.das@amd.com> Cc: Will Deacon <will@kernel.org> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-csky@vger.kernel.org Cc: linux-riscv@lists.infradead.org Link: https://lore.kernel.org/r/20230606014559.21783-3-leo.yan@linaro.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Linux kernel ============ There are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. Please read Documentation/admin-guide/README.rst first. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. The formatted documentation can also be read online at: https://www.kernel.org/doc/html/latest/ There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.
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