Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754699Ab3HXPfw (ORCPT ); Sat, 24 Aug 2013 11:35:52 -0400 Received: from top.free-electrons.com ([176.31.233.9]:54619 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755269Ab3HXPfs (ORCPT ); Sat, 24 Aug 2013 11:35:48 -0400 From: Ezequiel Garcia To: , Cc: Thomas Petazzoni , Gregory Clement , Lior Amsalem , Baruch Siach , Will Deacon , Sebastian Hesselbarth , Russell King , Catalin Marinas , Ezequiel Garcia Subject: [PATCH v4 2/4] ARM: Add atomic_io_modify optimized routines Date: Sat, 24 Aug 2013 12:35:30 -0300 Message-Id: <1377358532-23802-3-git-send-email-ezequiel.garcia@free-electrons.com> X-Mailer: git-send-email 1.8.1.5 In-Reply-To: <1377358532-23802-1-git-send-email-ezequiel.garcia@free-electrons.com> References: <1377358532-23802-1-git-send-email-ezequiel.garcia@free-electrons.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2298 Lines: 73 Implement arch-specific atomic_io_modify and atomic_io_modify_relaxed, which are based on writel/readl_relaxed and writel_relaxed/readl_relaxed, respectively. In both cases, by relaxing the readl, perfomance can be improved. Signed-off-by: Ezequiel Garcia --- arch/arm/include/asm/io.h | 4 ++++ arch/arm/kernel/io.c | 29 +++++++++++++++++++++++++++++ 2 files changed, 33 insertions(+) diff --git a/arch/arm/include/asm/io.h b/arch/arm/include/asm/io.h index d070741..53637b6 100644 --- a/arch/arm/include/asm/io.h +++ b/arch/arm/include/asm/io.h @@ -397,5 +397,9 @@ extern int devmem_is_allowed(unsigned long pfn); extern void register_isa_ports(unsigned int mmio, unsigned int io, unsigned int io_shift); +#define __HAVE_ARCH_ATOMIC_IO_MODIFY +extern void atomic_io_modify(void __iomem *reg, u32 mask, u32 set); +extern void atomic_io_modify_relaxed(void __iomem *reg, u32 mask, u32 set); + #endif /* __KERNEL__ */ #endif /* __ASM_ARM_IO_H */ diff --git a/arch/arm/kernel/io.c b/arch/arm/kernel/io.c index dcd5b4d..a8c9c9b 100644 --- a/arch/arm/kernel/io.c +++ b/arch/arm/kernel/io.c @@ -1,6 +1,35 @@ #include #include #include +#include + +static DEFINE_RAW_SPINLOCK(__io_lock); + +void atomic_io_modify_relaxed(void __iomem *reg, u32 mask, u32 set) +{ + unsigned long flags; + u32 value; + + raw_spin_lock_irqsave(&__io_lock, flags); + value = readl_relaxed(reg) & ~mask; + value |= (set & mask); + writel_relaxed(value, reg); + raw_spin_unlock_irqrestore(&__io_lock, flags); +} +EXPORT_SYMBOL(atomic_io_modify_relaxed); + +void atomic_io_modify(void __iomem *reg, u32 mask, u32 set) +{ + unsigned long flags; + u32 value; + + raw_spin_lock_irqsave(&__io_lock, flags); + value = readl_relaxed(reg) & ~mask; + value |= (set & mask); + writel(value, reg); + raw_spin_unlock_irqrestore(&__io_lock, flags); +} +EXPORT_SYMBOL(atomic_io_modify); /* * Copy data from IO memory space to "real" memory space. -- 1.8.1.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/