forked from Minki/linux
c27a0d75b3
This arch-independent routine copies data to a memory-mapped I/O region,
using 32-bit accesses. The naming is double-underscored to make it clear
that it does not guarantee write ordering, nor does it perform a memory
barrier afterwards; the kernel doc also explicitly states this. This style
of access is required by some devices.
This change also introduces include/linux/io.h, at Andrew's suggestion. It
only has one occupant at the moment, but is a logical destination for
oft-replicated contents of include/asm-*/{io,iomap}.h to migrate to.
Signed-off-by: Bryan O'Sullivan <bos@pathscale.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
43 lines
1.4 KiB
C
43 lines
1.4 KiB
C
/*
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* Copyright 2006 PathScale, Inc. All Rights Reserved.
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*
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* This file is free software; you can redistribute it and/or modify
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* it under the terms of version 2 of the GNU General Public License
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* as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
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*/
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#include <linux/io.h>
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#include <linux/module.h>
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/**
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* __iowrite32_copy - copy data to MMIO space, in 32-bit units
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* @to: destination, in MMIO space (must be 32-bit aligned)
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* @from: source (must be 32-bit aligned)
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* @count: number of 32-bit quantities to copy
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*
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* Copy data from kernel space to MMIO space, in units of 32 bits at a
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* time. Order of access is not guaranteed, nor is a memory barrier
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* performed afterwards.
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*/
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void __attribute__((weak)) __iowrite32_copy(void __iomem *to,
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const void *from,
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size_t count)
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{
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u32 __iomem *dst = to;
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const u32 *src = from;
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const u32 *end = src + count;
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while (src < end)
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__raw_writel(*src++, dst++);
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}
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EXPORT_SYMBOL_GPL(__iowrite32_copy);
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