forked from Minki/linux
b5ee900258
Let's provide an overridable default instead of having every machine class define __virt_to_bus and __bus_to_virt to the same thing. What most platforms are using is bus_addr == phys_addr so such is the default. One exception is ebsa110 which has no DMA what so ever, so the actual definition is not important except only for proper compilation. Also added a comment about the special footbridge bus translation. Let's also remove comments alluding to set_dma_addr which is not (and should not) be commonly used. Signed-off-by: Nicolas Pitre <nico@marvell.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
67 lines
1.7 KiB
C
67 lines
1.7 KiB
C
/*
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* arch/arm/mach-footbridge/include/mach/memory.h
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*
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* Copyright (C) 1996-1999 Russell King.
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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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* Changelog:
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* 20-Oct-1996 RMK Created
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* 31-Dec-1997 RMK Fixed definitions to reduce warnings.
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* 17-May-1998 DAG Added __virt_to_bus and __bus_to_virt functions.
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* 21-Nov-1998 RMK Changed __virt_to_bus and __bus_to_virt to macros.
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* 21-Mar-1999 RMK Added PAGE_OFFSET for co285 architecture.
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* Renamed to memory.h
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* Moved PAGE_OFFSET and TASK_SIZE here
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*/
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#ifndef __ASM_ARCH_MEMORY_H
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#define __ASM_ARCH_MEMORY_H
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#if defined(CONFIG_FOOTBRIDGE_ADDIN)
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/*
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* If we may be using add-in footbridge mode, then we must
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* use the out-of-line translation that makes use of the
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* PCI BAR
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*/
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#ifndef __ASSEMBLY__
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extern unsigned long __virt_to_bus(unsigned long);
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extern unsigned long __bus_to_virt(unsigned long);
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#endif
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#define __virt_to_bus __virt_to_bus
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#define __bus_to_virt __bus_to_virt
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#elif defined(CONFIG_FOOTBRIDGE_HOST)
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/*
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* The footbridge is programmed to expose the system RAM at the corresponding
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* address. So, if PAGE_OFFSET is 0xc0000000, RAM appears at 0xe0000000.
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* If 0x80000000, then its exposed at 0xa0000000 on the bus. etc.
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* The only requirement is that the RAM isn't placed at bus address 0 which
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* would clash with VGA cards.
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*/
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#define __virt_to_bus(x) ((x) - 0xe0000000)
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#define __bus_to_virt(x) ((x) + 0xe0000000)
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#else
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#error "Undefined footbridge mode"
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#endif
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/*
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* Cache flushing area.
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*/
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#define FLUSH_BASE 0xf9000000
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/*
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* Physical DRAM offset.
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*/
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#define PHYS_OFFSET UL(0x00000000)
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#define FLUSH_BASE_PHYS 0x50000000
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#endif
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