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| author | Russell King <rmk+kernel@arm.linux.org.uk> | 2015-11-16 17:41:02 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-12-13 19:59:48 -0800 |
| commit | f5ce6edd22cff94e7b4a17f26cad43e60ae3d080 (patch) | |
| tree | c8c986ba2bc78c8b3b5a985c4faf4f73791258b4 /drivers | |
| parent | 7ec758718920e5e5876d0d02ece6855128c8eb1e (diff) | |
| download | linux-stable-f5ce6edd22cff94e7b4a17f26cad43e60ae3d080.tar.gz linux-stable-f5ce6edd22cff94e7b4a17f26cad43e60ae3d080.tar.bz2 linux-stable-f5ce6edd22cff94e7b4a17f26cad43e60ae3d080.zip | |
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')
| -rw-r--r-- | drivers/tty/serial/amba-pl011.c | 6 |
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); } /* |