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authorRussell King <rmk+kernel@arm.linux.org.uk>2015-11-16 17:41:02 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-12-13 19:59:48 -0800
commitf5ce6edd22cff94e7b4a17f26cad43e60ae3d080 (patch)
treec8c986ba2bc78c8b3b5a985c4faf4f73791258b4 /drivers/tty/serial/amba-pl011.c
parent7ec758718920e5e5876d0d02ece6855128c8eb1e (diff)
downloadblackbird-op-linux-f5ce6edd22cff94e7b4a17f26cad43e60ae3d080.tar.gz
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tty: amba-pl011: switch to using relaxed IO accessors
Using relaxed IO accessors allows GCC to better optimise this code as we eliminate the heavy memory barriers - for example, GCC can now cache the address of a register across a read-modify-write sequence, rather than reloading the base address, offset and access size flag. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial/amba-pl011.c')
-rw-r--r--drivers/tty/serial/amba-pl011.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 295f0be128f9..3b24aea343de 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -262,7 +262,7 @@ static unsigned int pl011_read(const struct uart_amba_port *uap,
{
void __iomem *addr = uap->port.membase + pl011_reg_to_offset(uap, reg);
- return uap->access_32b ? readl(addr) : readw(addr);
+ return uap->access_32b ? readl_relaxed(addr) : readw_relaxed(addr);
}
static void pl011_write(unsigned int val, const struct uart_amba_port *uap,
@@ -271,9 +271,9 @@ static void pl011_write(unsigned int val, const struct uart_amba_port *uap,
void __iomem *addr = uap->port.membase + pl011_reg_to_offset(uap, reg);
if (uap->access_32b)
- writel(val, addr);
+ writel_relaxed(val, addr);
else
- writew(val, addr);
+ writew_relaxed(val, addr);
}
/*
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