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From: Andy Chiu <andy.chiu@sifive.com>
Date: Mon, 18 Mar 2024 18:39:56 +0800
Subject: [PATCH v3 3/7] riscv: cpufeature: call match_isa_ext() for
 single-letter extensions
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Message-Id: <20240318-zve-detection-v3-3-e12d42107fa8@sifive.com>
References: <20240318-zve-detection-v3-0-e12d42107fa8@sifive.com>
In-Reply-To: <20240318-zve-detection-v3-0-e12d42107fa8@sifive.com>
To: Paul Walmsley <paul.walmsley@sifive.com>, 
 Palmer Dabbelt <palmer@dabbelt.com>, Albert Ou <aou@eecs.berkeley.edu>, 
 Andy Chiu <andy.chiu@sifive.com>, Vincent Chen <vincent.chen@sifive.com>, 
 Heiko Stuebner <heiko@sntech.de>, Conor Dooley <conor.dooley@microchip.com>, 
 Conor Dooley <conor@kernel.org>, Rob Herring <robh+dt@kernel.org>, 
 Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>, 
 Jonathan Corbet <corbet@lwn.net>
Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, 
 Palmer Dabbelt <palmer@rivosinc.com>, 
 Greentime Hu <greentime.hu@sifive.com>, Guo Ren <guoren@kernel.org>, 
 devicetree@vger.kernel.org, linux-doc@vger.kernel.org

Single-letter extensions may also imply multiple subextensions. For
example, Vector extension implies zve64d, and zve64d implies zve64f.

Extension parsing for "riscv,isa-extensions" has the ability to resolve
the dependency by calling match_isa_ext(). This patch makes deprecated
parser call the same function for single letter extensions.

Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
---
Changelog v3:
- Remove set_bit for single-letter extensions as they are all checked in
match_isa_ext. (Clément)
---
 arch/riscv/kernel/cpufeature.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index db9fb90cb272..cbdd63165e85 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -457,16 +457,15 @@ static void __init riscv_parse_isa_string(unsigned long *this_hwcap, struct risc
 
 		if (unlikely(ext_err))
 			continue;
+
+		for (int i = 0; i < riscv_isa_ext_count; i++)
+			match_isa_ext(&riscv_isa_ext[i], ext, ext_end, isainfo);
+
 		if (!ext_long) {
 			int nr = tolower(*ext) - 'a';
 
-			if (riscv_isa_extension_check(nr)) {
+			if (riscv_isa_extension_check(nr))
 				*this_hwcap |= isa2hwcap[nr];
-				set_bit(nr, isainfo->isa);
-			}
-		} else {
-			for (int i = 0; i < riscv_isa_ext_count; i++)
-				match_isa_ext(&riscv_isa_ext[i], ext, ext_end, isainfo);
 		}
 	}
 }

-- 
2.44.0.rc2