linux-kernel - [PATCH v3 01/20] riscv: hwprobe: factorize hwprobe ISA extension reporting

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Message-ID: <20231107105556.517187-2-cleger@rivosinc.com>
Date:   Tue,  7 Nov 2023 11:55:37 +0100
From:   Clément Léger <cleger@...osinc.com>
To:     linux-riscv@...ts.infradead.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-doc@...r.kernel.org
Cc:     Clément Léger <cleger@...osinc.com>,
        Palmer Dabbelt <palmer@...osinc.com>,
        Paul Walmsley <paul.walmsley@...ive.com>,
        Rob Herring <robh+dt@...nel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
        Albert Ou <aou@...s.berkeley.edu>,
        Jonathan Corbet <corbet@....net>,
        Andrew Jones <ajones@...tanamicro.com>,
        Evan Green <evan@...osinc.com>,
        Conor Dooley <conor@...nel.org>,
        Samuel Ortiz <sameo@...osinc.com>
Subject: [PATCH v3 01/20] riscv: hwprobe: factorize hwprobe ISA extension reporting

Factorize ISA extension reporting by using a macro rather than
copy/pasting extension names. This will allow adding new extensions more
easily.

Signed-off-by: Clément Léger <cleger@...osinc.com>
Reviewed-by: Evan Green <evan@...osinc.com>
---
 arch/riscv/kernel/sys_riscv.c | 32 ++++++++++++++++++--------------
 1 file changed, 18 insertions(+), 14 deletions(-)

diff --git a/arch/riscv/kernel/sys_riscv.c b/arch/riscv/kernel/sys_riscv.c
index b651ec698a91..49aa4e82797c 100644
--- a/arch/riscv/kernel/sys_riscv.c
+++ b/arch/riscv/kernel/sys_riscv.c
@@ -145,20 +145,24 @@ static void hwprobe_isa_ext0(struct riscv_hwprobe *pair,
 	for_each_cpu(cpu, cpus) {
 		struct riscv_isainfo *isainfo = &hart_isa[cpu];
 
-		if (riscv_isa_extension_available(isainfo->isa, ZBA))
-			pair->value |= RISCV_HWPROBE_EXT_ZBA;
-		else
-			missing |= RISCV_HWPROBE_EXT_ZBA;
-
-		if (riscv_isa_extension_available(isainfo->isa, ZBB))
-			pair->value |= RISCV_HWPROBE_EXT_ZBB;
-		else
-			missing |= RISCV_HWPROBE_EXT_ZBB;
-
-		if (riscv_isa_extension_available(isainfo->isa, ZBS))
-			pair->value |= RISCV_HWPROBE_EXT_ZBS;
-		else
-			missing |= RISCV_HWPROBE_EXT_ZBS;
+#define CHECK_ISA_EXT(__ext)							\
+		do {								\
+			if (riscv_isa_extension_available(isainfo->isa, __ext))	\
+				pair->value |= RISCV_HWPROBE_EXT_##__ext;	\
+			else							\
+				missing |= RISCV_HWPROBE_EXT_##__ext;		\
+		} while (false)
+
+		/*
+		 * Only use CHECK_ISA_EXT() for extensions which are usable by
+		 * userspace with respect to the kernel current configuration.
+		 * For instance, ISA extensions that use float operations
+		 * should not be exposed when CONFIG_FPU is not enabled.
+		 */
+		CHECK_ISA_EXT(ZBA);
+		CHECK_ISA_EXT(ZBB);
+		CHECK_ISA_EXT(ZBS);
+#undef CHECK_ISA_EXT
 	}
 
 	/* Now turn off reporting features if any CPU is missing it. */
-- 
2.42.0