linux-kernel - [PATCH 2/4] riscv: drop some idefs from CMO initialization

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Message-Id: <20220901222744.2210215-2-heiko@sntech.de>
Date:   Fri,  2 Sep 2022 00:27:42 +0200
From:   Heiko Stuebner <heiko@...ech.de>
To:     paul.walmsley@...ive.com, palmer@...belt.com, aou@...s.berkeley.edu
Cc:     conor.dooley@...rochip.com, guoren@...nel.org,
        apatel@...tanamicro.com, atishp@...osinc.com,
        linux-riscv@...ts.infradead.org, linux-kernel@...r.kernel.org,
        Heiko Stuebner <heiko@...ech.de>
Subject: [PATCH 2/4] riscv: drop some idefs from CMO initialization

Wrapping things in #ifdefs makes the code harder to read
while we also have IS_ENABLED() macros to do this in regular code
and the extension detection is not _that_ runtime critical.

So define a stub for riscv_noncoherent_supported() in the
non-CONFIG_RISCV_DMA_NONCOHERENT case and move the code to
us IS_ENABLED.

Suggested-by: Conor Dooley <conor.dooley@...rochip.com>
Signed-off-by: Heiko Stuebner <heiko@...ech.de>
---
 arch/riscv/errata/thead/errata.c    |  7 +++----
 arch/riscv/include/asm/cacheflush.h |  2 ++
 arch/riscv/kernel/cpufeature.c      | 22 +++++++++-------------
 3 files changed, 14 insertions(+), 17 deletions(-)

diff --git a/arch/riscv/errata/thead/errata.c b/arch/riscv/errata/thead/errata.c
index 202c83f677b2..bffa711aaf64 100644
--- a/arch/riscv/errata/thead/errata.c
+++ b/arch/riscv/errata/thead/errata.c
@@ -30,7 +30,9 @@ static bool errata_probe_pbmt(unsigned int stage,
 static bool errata_probe_cmo(unsigned int stage,
 			     unsigned long arch_id, unsigned long impid)
 {
-#ifdef CONFIG_ERRATA_THEAD_CMO
+	if (!IS_ENABLED(CONFIG_ERRATA_THEAD_CMO))
+		return false;
+
 	if (arch_id != 0 || impid != 0)
 		return false;
 
@@ -39,9 +41,6 @@ static bool errata_probe_cmo(unsigned int stage,
 
 	riscv_noncoherent_supported();
 	return true;
-#else
-	return false;
-#endif
 }
 
 static u32 thead_errata_probe(unsigned int stage,
diff --git a/arch/riscv/include/asm/cacheflush.h b/arch/riscv/include/asm/cacheflush.h
index a60acaecfeda..4363d0beb38a 100644
--- a/arch/riscv/include/asm/cacheflush.h
+++ b/arch/riscv/include/asm/cacheflush.h
@@ -50,6 +50,8 @@ static inline void riscv_init_cbom_blocksize(void) { }
 
 #ifdef CONFIG_RISCV_DMA_NONCOHERENT
 void riscv_noncoherent_supported(void);
+#else
+static inline void riscv_noncoherent_supported(void) {}
 #endif
 
 /*
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index 764ea220161f..729f7a218093 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -264,21 +264,17 @@ static bool __init_or_module cpufeature_probe_svpbmt(unsigned int stage)
 
 static bool __init_or_module cpufeature_probe_zicbom(unsigned int stage)
 {
-#ifdef CONFIG_RISCV_ISA_ZICBOM
-	switch (stage) {
-	case RISCV_ALTERNATIVES_EARLY_BOOT:
+	if (!IS_ENABLED(CONFIG_RISCV_ISA_ZICBOM))
+		return false;
+
+	if (stage == RISCV_ALTERNATIVES_EARLY_BOOT)
+		return false;
+
+	if (!riscv_isa_extension_available(NULL, ZICBOM))
 		return false;
-	default:
-		if (riscv_isa_extension_available(NULL, ZICBOM)) {
-			riscv_noncoherent_supported();
-			return true;
-		} else {
-			return false;
-		}
-	}
-#endif
 
-	return false;
+	riscv_noncoherent_supported();
+	return true;
 }
 
 /*
-- 
2.35.1