fc47897d2c
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>
85 lines
2.2 KiB
C
85 lines
2.2 KiB
C
/*
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* Based on arch/arm/mm/ioremap.c
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*
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* (C) Copyright 1995 1996 Linus Torvalds
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* Hacked for ARM by Phil Blundell <philb@gnu.org>
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* Hacked to allow all architectures to build, and various cleanups
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* by Russell King
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* Copyright (C) 2012 ARM Ltd.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* 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, see <http://www.gnu.org/licenses/>.
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*/
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#include <linux/export.h>
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#include <linux/mm.h>
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#include <linux/vmalloc.h>
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#include <linux/io.h>
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static void __iomem *__ioremap_caller(phys_addr_t phys_addr, size_t size,
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pgprot_t prot, void *caller)
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{
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unsigned long last_addr;
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unsigned long offset = phys_addr & ~PAGE_MASK;
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int err;
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unsigned long addr;
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struct vm_struct *area;
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/*
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* Page align the mapping address and size, taking account of any
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* offset.
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*/
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phys_addr &= PAGE_MASK;
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size = PAGE_ALIGN(size + offset);
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/*
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* Don't allow wraparound, zero size or outside PHYS_MASK.
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*/
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last_addr = phys_addr + size - 1;
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if (!size || last_addr < phys_addr || (last_addr & ~PHYS_MASK))
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return NULL;
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/*
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* Don't allow RAM to be mapped.
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*/
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if (WARN_ON(pfn_valid(__phys_to_pfn(phys_addr))))
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return NULL;
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area = get_vm_area_caller(size, VM_IOREMAP, caller);
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if (!area)
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return NULL;
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addr = (unsigned long)area->addr;
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err = ioremap_page_range(addr, addr + size, phys_addr, prot);
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if (err) {
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vunmap((void *)addr);
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return NULL;
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}
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return (void __iomem *)(offset + addr);
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}
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void __iomem *__ioremap(phys_addr_t phys_addr, size_t size, pgprot_t prot)
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{
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return __ioremap_caller(phys_addr, size, prot,
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__builtin_return_address(0));
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}
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EXPORT_SYMBOL(__ioremap);
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void __iounmap(volatile void __iomem *io_addr)
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{
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void *addr = (void *)(PAGE_MASK & (unsigned long)io_addr);
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vunmap(addr);
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}
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EXPORT_SYMBOL(__iounmap);
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