From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3E8F92F12DD; Fri, 17 Oct 2025 15:03:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760713423; cv=none; b=Snrj2+YmMGlenrUJqJtWwQQlyhTByAdNaGvcWhwRvWOmo/B4PdGmgYsZc4h3oATYm6bphJy7NmJAxwRnUWA5R5w1HAzB37n8S15HBXfKtjXRwxa53KyqO62Yo7pUOqhK9pV6ChZ6JAxyal8pdVHDzMxLSuQmZFLmmvQb40Xdf4k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760713423; c=relaxed/simple; bh=GP6GRF+EUTBsmpYDR7VMoT5Q16JGL338WpNpbLI3x7g=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=kxO9dWYS31xYpl+WD1j6lPvWyt7Be9M/W5Z/STuva8GpzdCBYgU+M37J6KqUpR7laTRk8fKxdU0ivzqNaduXw9sOeyjXH1MZdZyATF4w+KQFi+mEtbq26UWbvMw7fZCZwtd6JiwB1o9qmi/rYBkTjRDkh27Rdga/kqqvGAhThA4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=XGJixTdr; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="XGJixTdr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BCA0BC4CEE7; Fri, 17 Oct 2025 15:03:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1760713423; bh=GP6GRF+EUTBsmpYDR7VMoT5Q16JGL338WpNpbLI3x7g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XGJixTdrYOL27TUH1Mv5Vz6CCbVTZELj6Ml/+O7fOlXbJ9+56MJhRLGyQUNJRwWm9 AII/60zQtCjlmVY8ePcZtnpaJjlpjsEag+RDyfvnUcG+FMJ8s5xgzFCq9aK9j+Ypke yAiU+z2sQWfhS8z0JTIKN2bvxzEdpFq3txaeg9g8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Varad Gautam , Arnd Bergmann , Sasha Levin Subject: [PATCH 6.1 159/168] asm-generic/io.h: Skip trace helpers if rwmmio events are disabled Date: Fri, 17 Oct 2025 16:53:58 +0200 Message-ID: <20251017145134.905978349@linuxfoundation.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251017145129.000176255@linuxfoundation.org> References: <20251017145129.000176255@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Varad Gautam [ Upstream commit 8327bd4fcb6c1dab01ce5c6ff00b42496836dcd2 ] With `CONFIG_TRACE_MMIO_ACCESS=y`, the `{read,write}{b,w,l,q}{_relaxed}()` mmio accessors unconditionally call `log_{post_}{read,write}_mmio()` helpers, which in turn call the ftrace ops for `rwmmio` trace events This adds a performance penalty per mmio accessor call, even when `rwmmio` events are disabled at runtime (~80% overhead on local measurement). Guard these with `tracepoint_enabled()`. Signed-off-by: Varad Gautam Fixes: 210031971cdd ("asm-generic/io: Add logging support for MMIO accessors") Cc: stable@vger.kernel.org Signed-off-by: Arnd Bergmann Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- include/asm-generic/io.h | 98 +++++++++++++++++++++++++++++++---------------- 1 file changed, 66 insertions(+), 32 deletions(-) --- a/include/asm-generic/io.h +++ b/include/asm-generic/io.h @@ -74,6 +74,7 @@ #if IS_ENABLED(CONFIG_TRACE_MMIO_ACCESS) && !(defined(__DISABLE_TRACE_MMIO__)) #include +#define rwmmio_tracepoint_enabled(tracepoint) tracepoint_enabled(tracepoint) DECLARE_TRACEPOINT(rwmmio_write); DECLARE_TRACEPOINT(rwmmio_post_write); DECLARE_TRACEPOINT(rwmmio_read); @@ -90,6 +91,7 @@ void log_post_read_mmio(u64 val, u8 widt #else +#define rwmmio_tracepoint_enabled(tracepoint) false static inline void log_write_mmio(u64 val, u8 width, volatile void __iomem *addr, unsigned long caller_addr, unsigned long caller_addr0) {} static inline void log_post_write_mmio(u64 val, u8 width, volatile void __iomem *addr, @@ -188,11 +190,13 @@ static inline u8 readb(const volatile vo { u8 val; - log_read_mmio(8, addr, _THIS_IP_, _RET_IP_); + if (rwmmio_tracepoint_enabled(rwmmio_read)) + log_read_mmio(8, addr, _THIS_IP_, _RET_IP_); __io_br(); val = __raw_readb(addr); __io_ar(val); - log_post_read_mmio(val, 8, addr, _THIS_IP_, _RET_IP_); + if (rwmmio_tracepoint_enabled(rwmmio_post_read)) + log_post_read_mmio(val, 8, addr, _THIS_IP_, _RET_IP_); return val; } #endif @@ -203,11 +207,13 @@ static inline u16 readw(const volatile v { u16 val; - log_read_mmio(16, addr, _THIS_IP_, _RET_IP_); + if (rwmmio_tracepoint_enabled(rwmmio_read)) + log_read_mmio(16, addr, _THIS_IP_, _RET_IP_); __io_br(); val = __le16_to_cpu((__le16 __force)__raw_readw(addr)); __io_ar(val); - log_post_read_mmio(val, 16, addr, _THIS_IP_, _RET_IP_); + if (rwmmio_tracepoint_enabled(rwmmio_post_read)) + log_post_read_mmio(val, 16, addr, _THIS_IP_, _RET_IP_); return val; } #endif @@ -218,11 +224,13 @@ static inline u32 readl(const volatile v { u32 val; - log_read_mmio(32, addr, _THIS_IP_, _RET_IP_); + if (rwmmio_tracepoint_enabled(rwmmio_read)) + log_read_mmio(32, addr, _THIS_IP_, _RET_IP_); __io_br(); val = __le32_to_cpu((__le32 __force)__raw_readl(addr)); __io_ar(val); - log_post_read_mmio(val, 32, addr, _THIS_IP_, _RET_IP_); + if (rwmmio_tracepoint_enabled(rwmmio_post_read)) + log_post_read_mmio(val, 32, addr, _THIS_IP_, _RET_IP_); return val; } #endif @@ -234,11 +242,13 @@ static inline u64 readq(const volatile v { u64 val; - log_read_mmio(64, addr, _THIS_IP_, _RET_IP_); + if (rwmmio_tracepoint_enabled(rwmmio_read)) + log_read_mmio(64, addr, _THIS_IP_, _RET_IP_); __io_br(); val = __le64_to_cpu((__le64 __force)__raw_readq(addr)); __io_ar(val); - log_post_read_mmio(val, 64, addr, _THIS_IP_, _RET_IP_); + if (rwmmio_tracepoint_enabled(rwmmio_post_read)) + log_post_read_mmio(val, 64, addr, _THIS_IP_, _RET_IP_); return val; } #endif @@ -248,11 +258,13 @@ static inline u64 readq(const volatile v #define writeb writeb static inline void writeb(u8 value, volatile void __iomem *addr) { - log_write_mmio(value, 8, addr, _THIS_IP_, _RET_IP_); + if (rwmmio_tracepoint_enabled(rwmmio_write)) + log_write_mmio(value, 8, addr, _THIS_IP_, _RET_IP_); __io_bw(); __raw_writeb(value, addr); __io_aw(); - log_post_write_mmio(value, 8, addr, _THIS_IP_, _RET_IP_); + if (rwmmio_tracepoint_enabled(rwmmio_post_write)) + log_post_write_mmio(value, 8, addr, _THIS_IP_, _RET_IP_); } #endif @@ -260,11 +272,13 @@ static inline void writeb(u8 value, vola #define writew writew static inline void writew(u16 value, volatile void __iomem *addr) { - log_write_mmio(value, 16, addr, _THIS_IP_, _RET_IP_); + if (rwmmio_tracepoint_enabled(rwmmio_write)) + log_write_mmio(value, 16, addr, _THIS_IP_, _RET_IP_); __io_bw(); __raw_writew((u16 __force)cpu_to_le16(value), addr); __io_aw(); - log_post_write_mmio(value, 16, addr, _THIS_IP_, _RET_IP_); + if (rwmmio_tracepoint_enabled(rwmmio_post_write)) + log_post_write_mmio(value, 16, addr, _THIS_IP_, _RET_IP_); } #endif @@ -272,11 +286,13 @@ static inline void writew(u16 value, vol #define writel writel static inline void writel(u32 value, volatile void __iomem *addr) { - log_write_mmio(value, 32, addr, _THIS_IP_, _RET_IP_); + if (rwmmio_tracepoint_enabled(rwmmio_write)) + log_write_mmio(value, 32, addr, _THIS_IP_, _RET_IP_); __io_bw(); __raw_writel((u32 __force)__cpu_to_le32(value), addr); __io_aw(); - log_post_write_mmio(value, 32, addr, _THIS_IP_, _RET_IP_); + if (rwmmio_tracepoint_enabled(rwmmio_post_write)) + log_post_write_mmio(value, 32, addr, _THIS_IP_, _RET_IP_); } #endif @@ -285,11 +301,13 @@ static inline void writel(u32 value, vol #define writeq writeq static inline void writeq(u64 value, volatile void __iomem *addr) { - log_write_mmio(value, 64, addr, _THIS_IP_, _RET_IP_); + if (rwmmio_tracepoint_enabled(rwmmio_write)) + log_write_mmio(value, 64, addr, _THIS_IP_, _RET_IP_); __io_bw(); __raw_writeq((u64 __force)__cpu_to_le64(value), addr); __io_aw(); - log_post_write_mmio(value, 64, addr, _THIS_IP_, _RET_IP_); + if (rwmmio_tracepoint_enabled(rwmmio_post_write)) + log_post_write_mmio(value, 64, addr, _THIS_IP_, _RET_IP_); } #endif #endif /* CONFIG_64BIT */ @@ -305,9 +323,11 @@ static inline u8 readb_relaxed(const vol { u8 val; - log_read_mmio(8, addr, _THIS_IP_, _RET_IP_); + if (rwmmio_tracepoint_enabled(rwmmio_read)) + log_read_mmio(8, addr, _THIS_IP_, _RET_IP_); val = __raw_readb(addr); - log_post_read_mmio(val, 8, addr, _THIS_IP_, _RET_IP_); + if (rwmmio_tracepoint_enabled(rwmmio_post_read)) + log_post_read_mmio(val, 8, addr, _THIS_IP_, _RET_IP_); return val; } #endif @@ -318,9 +338,11 @@ static inline u16 readw_relaxed(const vo { u16 val; - log_read_mmio(16, addr, _THIS_IP_, _RET_IP_); + if (rwmmio_tracepoint_enabled(rwmmio_read)) + log_read_mmio(16, addr, _THIS_IP_, _RET_IP_); val = __le16_to_cpu((__le16 __force)__raw_readw(addr)); - log_post_read_mmio(val, 16, addr, _THIS_IP_, _RET_IP_); + if (rwmmio_tracepoint_enabled(rwmmio_post_read)) + log_post_read_mmio(val, 16, addr, _THIS_IP_, _RET_IP_); return val; } #endif @@ -331,9 +353,11 @@ static inline u32 readl_relaxed(const vo { u32 val; - log_read_mmio(32, addr, _THIS_IP_, _RET_IP_); + if (rwmmio_tracepoint_enabled(rwmmio_read)) + log_read_mmio(32, addr, _THIS_IP_, _RET_IP_); val = __le32_to_cpu((__le32 __force)__raw_readl(addr)); - log_post_read_mmio(val, 32, addr, _THIS_IP_, _RET_IP_); + if (rwmmio_tracepoint_enabled(rwmmio_post_read)) + log_post_read_mmio(val, 32, addr, _THIS_IP_, _RET_IP_); return val; } #endif @@ -344,9 +368,11 @@ static inline u64 readq_relaxed(const vo { u64 val; - log_read_mmio(64, addr, _THIS_IP_, _RET_IP_); + if (rwmmio_tracepoint_enabled(rwmmio_read)) + log_read_mmio(64, addr, _THIS_IP_, _RET_IP_); val = __le64_to_cpu((__le64 __force)__raw_readq(addr)); - log_post_read_mmio(val, 64, addr, _THIS_IP_, _RET_IP_); + if (rwmmio_tracepoint_enabled(rwmmio_post_read)) + log_post_read_mmio(val, 64, addr, _THIS_IP_, _RET_IP_); return val; } #endif @@ -355,9 +381,11 @@ static inline u64 readq_relaxed(const vo #define writeb_relaxed writeb_relaxed static inline void writeb_relaxed(u8 value, volatile void __iomem *addr) { - log_write_mmio(value, 8, addr, _THIS_IP_, _RET_IP_); + if (rwmmio_tracepoint_enabled(rwmmio_write)) + log_write_mmio(value, 8, addr, _THIS_IP_, _RET_IP_); __raw_writeb(value, addr); - log_post_write_mmio(value, 8, addr, _THIS_IP_, _RET_IP_); + if (rwmmio_tracepoint_enabled(rwmmio_post_write)) + log_post_write_mmio(value, 8, addr, _THIS_IP_, _RET_IP_); } #endif @@ -365,9 +393,11 @@ static inline void writeb_relaxed(u8 val #define writew_relaxed writew_relaxed static inline void writew_relaxed(u16 value, volatile void __iomem *addr) { - log_write_mmio(value, 16, addr, _THIS_IP_, _RET_IP_); + if (rwmmio_tracepoint_enabled(rwmmio_write)) + log_write_mmio(value, 16, addr, _THIS_IP_, _RET_IP_); __raw_writew((u16 __force)cpu_to_le16(value), addr); - log_post_write_mmio(value, 16, addr, _THIS_IP_, _RET_IP_); + if (rwmmio_tracepoint_enabled(rwmmio_post_write)) + log_post_write_mmio(value, 16, addr, _THIS_IP_, _RET_IP_); } #endif @@ -375,9 +405,11 @@ static inline void writew_relaxed(u16 va #define writel_relaxed writel_relaxed static inline void writel_relaxed(u32 value, volatile void __iomem *addr) { - log_write_mmio(value, 32, addr, _THIS_IP_, _RET_IP_); + if (rwmmio_tracepoint_enabled(rwmmio_write)) + log_write_mmio(value, 32, addr, _THIS_IP_, _RET_IP_); __raw_writel((u32 __force)__cpu_to_le32(value), addr); - log_post_write_mmio(value, 32, addr, _THIS_IP_, _RET_IP_); + if (rwmmio_tracepoint_enabled(rwmmio_post_write)) + log_post_write_mmio(value, 32, addr, _THIS_IP_, _RET_IP_); } #endif @@ -385,9 +417,11 @@ static inline void writel_relaxed(u32 va #define writeq_relaxed writeq_relaxed static inline void writeq_relaxed(u64 value, volatile void __iomem *addr) { - log_write_mmio(value, 64, addr, _THIS_IP_, _RET_IP_); + if (rwmmio_tracepoint_enabled(rwmmio_write)) + log_write_mmio(value, 64, addr, _THIS_IP_, _RET_IP_); __raw_writeq((u64 __force)__cpu_to_le64(value), addr); - log_post_write_mmio(value, 64, addr, _THIS_IP_, _RET_IP_); + if (rwmmio_tracepoint_enabled(rwmmio_post_write)) + log_post_write_mmio(value, 64, addr, _THIS_IP_, _RET_IP_); } #endif