History log of /linux-master/arch/arm64/kernel/io.c
Revision Date Author Comments
# caab277b 02-Jun-2019 Thomas Gleixner <tglx@linutronix.de>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation this program is
distributed in the hope that it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose see the gnu general public license
for more details you should have received a copy of the gnu general
public license along with this program if not see http www gnu org
licenses

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 503 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Enrico Weigelt <info@metux.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190602204653.811534538@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# 9ca255bf 24-Oct-2017 Mark Salyzyn <salyzyn@android.com>

arm64: Avoid aligning normal memory pointers in __memcpy_{to,from}io

__memcpy_{to,from}io fall back to byte-at-a-time copying if both the
source and destination pointers are not 8-byte aligned. Since one of the
pointers always points at normal memory, this is unnecessary and
detrimental to performance, so only do byte copying until we hit an 8-byte
boundary for the device pointer.

This change was motivated by performance issues in the pstore driver.
On a test platform, measuring probe time for pstore, console buffer
size of 1/4MB and pmsg of 1/2MB, was in the 90-107ms region. Change
managed to reduce it to 10-25ms, an improvement in boot time.

Cc: Kees Cook <keescook@chromium.org>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Mark Salyzyn <salyzyn@android.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>


# 70ddb63a 20-Oct-2014 Joonwoo Park <joonwoop@codeaurora.org>

arm64: optimize memcpy_{from,to}io() and memset_io()

Optimize memcpy_{from,to}io() and memset_io() by transferring in 64 bit
as much as possible with minimized barrier usage. This simplest
optimization brings faster throughput compare to current byte-by-byte read
and write with barrier in the loop. Code's skeleton is taken from the
powerpc.

Link: http://lkml.kernel.org/p/20141020133304.GH23751@e104818-lin.cambridge.arm.com
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Trilok Soni <tsoni@codeaurora.org>
Signed-off-by: Joonwoo Park <joonwoop@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>


# fc47897d 05-Mar-2012 Catalin Marinas <catalin.marinas@arm.com>

arm64: Device specific operations

This patch adds several definitions for device communication, including
I/O accessors and ioremap(). The __raw_* accessors are implemented as
inline asm to avoid compiler generation of post-indexed accesses (less
efficient to emulate in a virtualised environment).

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Olof Johansson <olof@lixom.net>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>