linux/include/asm-arm/arch-ixp23xx/memory.h
Lennert Buytenhek a77bc69138 [ARM] 3539/1: ixp23xx: fix __arch_ixp23xx_is_coherent() for A1 stepping
Patch from Lennert Buytenhek

The current __ixp23xx_arch_is_coherent() check assumes that the
lower byte of IXP23XX_PRODUCT_ID is identical to the lower byte of
processor_id, but this is not the case, and because of this we were
incorrectly enabling coherency on A1 stepping CPUs.

Stepping A1 of the ixp2350, which has a PRODUCT_ID of 0x401, has '02'
in the lower byte of processor_id, while A2, with a PRODUCT_ID of
0x402, has '04' in the lower byte of processor_id.

So, to check for >= A2, we really need to check the lower byte of
processor_id against >= 4.

Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-06-02 19:51:50 +01:00

64 lines
1.5 KiB
C

/*
* include/asm-arm/arch-ixp23xx/memory.h
*
* Copyright (c) 2003-2004 Intel Corp.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*/
#ifndef __ASM_ARCH_MEMORY_H
#define __ASM_ARCH_MEMORY_H
#include <asm/hardware.h>
/*
* Physical DRAM offset.
*/
#define PHYS_OFFSET (0x00000000)
/*
* Virtual view <-> DMA view memory address translations
* virt_to_bus: Used to translate the virtual address to an
* address suitable to be passed to set_dma_addr
* bus_to_virt: Used to convert an address for DMA operations
* to an address that the kernel can use.
*/
#ifndef __ASSEMBLY__
#include <asm/mach-types.h>
#define __virt_to_bus(v) \
({ unsigned int ret; \
ret = ((__virt_to_phys(v) - 0x00000000) + \
(*((volatile int *)IXP23XX_PCI_SDRAM_BAR) & 0xfffffff0)); \
ret; })
#define __bus_to_virt(b) \
({ unsigned int data; \
data = *((volatile int *)IXP23XX_PCI_SDRAM_BAR); \
__phys_to_virt((((b - (data & 0xfffffff0)) + 0x00000000))); })
/*
* Coherency support. Only supported on A2 CPUs or on A1
* systems that have the cache coherency workaround.
*/
static inline int __ixp23xx_arch_is_coherent(void)
{
extern unsigned int processor_id;
if (((processor_id & 15) >= 4) || machine_is_roadrunner())
return 1;
return 0;
}
#define arch_is_coherent() __ixp23xx_arch_is_coherent()
#endif
#endif