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[70.228.75.190]) by smtp.gmail.com with ESMTPSA id u5sm8700000ooo.46.2022.02.10.13.40.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 10 Feb 2022 13:40:33 -0800 (PST) From: Atish Patra To: linux-kernel@vger.kernel.org Cc: Tsukasa OI , Atish Patra , Albert Ou , Atish Patra , Anup Patel , Damien Le Moal , devicetree@vger.kernel.org, Jisheng Zhang , Krzysztof Kozlowski , linux-riscv@lists.infradead.org, Palmer Dabbelt , Paul Walmsley , Rob Herring Subject: [PATCH v2 3/6] RISC-V: Extract multi-letter extension names from "riscv,isa" Date: Thu, 10 Feb 2022 13:40:15 -0800 Message-Id: <20220210214018.55739-4-atishp@rivosinc.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220210214018.55739-1-atishp@rivosinc.com> References: <20220210214018.55739-1-atishp@rivosinc.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org From: Tsukasa OI Currently, there is no usage for version numbers in extensions as any ratified non base ISA extension will always at v1.0. Extract the extension names in place for future parsing. Signed-off-by: Tsukasa OI [Improved commit text and comments] Signed-off-by: Atish Patra --- arch/riscv/kernel/cpufeature.c | 41 +++++++++++++++++++++++++--------- 1 file changed, 31 insertions(+), 10 deletions(-) diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c index e19ae4391a9b..e9e3b0693d16 100644 --- a/arch/riscv/kernel/cpufeature.c +++ b/arch/riscv/kernel/cpufeature.c @@ -102,6 +102,7 @@ void __init riscv_fill_hwcap(void) #endif for (; *isa; ++isa) { const char *ext = isa++; + const char *ext_end = isa; bool ext_long, ext_err = false; switch (*ext) { @@ -119,19 +120,39 @@ void __init riscv_fill_hwcap(void) ext_long = true; /* Multi-letter extension must be delimited */ for (; *isa && *isa != '_'; ++isa) - if (!islower(*isa) && !isdigit(*isa)) + if (unlikely(!islower(*isa) + && !isdigit(*isa))) ext_err = true; - /* ... but must be ignored. */ + /* Parse backwards */ + ext_end = isa; + if (unlikely(ext_err)) + break; + if (!isdigit(ext_end[-1])) + break; + /* Skip the minor version */ + while (isdigit(*--ext_end)) + ; + if (ext_end[0] != 'p' + || !isdigit(ext_end[-1])) { + /* Advance it to offset the pre-decrement */ + ++ext_end; + break; + } + /* Skip the major version */ + while (isdigit(*--ext_end)) + ; + ++ext_end; break; default: ext_long = false; - if (!islower(*ext)) { + if (unlikely(!islower(*ext))) { ext_err = true; break; } /* Find next extension */ if (!isdigit(*isa)) break; + /* Skip the minor version */ while (isdigit(*++isa)) ; if (*isa != 'p') @@ -140,20 +161,20 @@ void __init riscv_fill_hwcap(void) --isa; break; } + /* Skip the major version */ while (isdigit(*++isa)) ; break; } if (*isa != '_') --isa; - /* - * TODO: Full version-aware handling including - * multi-letter extensions will be added in-future. - */ - if (ext_err || ext_long) + + if (unlikely(ext_err)) continue; - this_hwcap |= isa2hwcap[(unsigned char)(*ext)]; - this_isa |= (1UL << (*ext - 'a')); + if (!ext_long) { + this_hwcap |= isa2hwcap[(unsigned char)(*ext)]; + this_isa |= (1UL << (*ext - 'a')); + } } /*