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IXP4xx: workaround for PCI prefetch problems near 64 MB boundary. 

Map unused registers at the end of DMA region at 64 MB to allow PCI masters
to cross the boundary when prefetching data from SDRAM.

Signed-off-by: Krzysztof Hałasa <khc@pm.waw.pl>
This commit is contained in:
Krzysztof Hałasa 2009-03-13 17:57:04 +01:00
parent fec6c6fec3
commit 0a07232ff6
2 changed files with 13 additions and 11 deletions
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1
arch/arm/include/asm/sizes.h
View File

@ -43,6 +43,7 @@
#define SZ_8M 0x00800000
#define SZ_16M 0x01000000
#define SZ_32M 0x02000000
#define SZ_48M 0x03000000
#define SZ_64M 0x04000000
#define SZ_128M 0x08000000
#define SZ_256M 0x10000000

23
arch/arm/mach-ixp4xx/common-pci.c
View File

@ -366,7 +366,7 @@ void __init ixp4xx_adjust_zones(int node, unsigned long *zone_size,
}
void __init ixp4xx_pci_preinit(void)
{
{
unsigned long cpuid = read_cpuid_id();
/*
@ -386,17 +386,17 @@ void __init ixp4xx_pci_preinit(void)
pr_debug("setup PCI-AHB(inbound) and AHB-PCI(outbound) address mappings\n");
/*
/*
* We use identity AHB->PCI address translation
* in the 0x48000000 to 0x4bffffff address space
*/
*PCI_PCIMEMBASE = 0x48494A4B;
/*
/*
* We also use identity PCI->AHB address translation
* in 4 16MB BARs that begin at the physical memory start
*/
*PCI_AHBMEMBASE = (PHYS_OFFSET & 0xFF000000) +
*PCI_AHBMEMBASE = (PHYS_OFFSET & 0xFF000000) +
((PHYS_OFFSET & 0xFF000000) >> 8) +
((PHYS_OFFSET & 0xFF000000) >> 16) +
((PHYS_OFFSET & 0xFF000000) >> 24) +
@ -408,18 +408,19 @@ void __init ixp4xx_pci_preinit(void)
pr_debug("setup BARs in controller\n");
/*
* We configure the PCI inbound memory windows to be
* We configure the PCI inbound memory windows to be
* 1:1 mapped to SDRAM
*/
local_write_config(PCI_BASE_ADDRESS_0, 4, PHYS_OFFSET + 0x00000000);
local_write_config(PCI_BASE_ADDRESS_1, 4, PHYS_OFFSET + 0x01000000);
local_write_config(PCI_BASE_ADDRESS_2, 4, PHYS_OFFSET + 0x02000000);
local_write_config(PCI_BASE_ADDRESS_3, 4, PHYS_OFFSET + 0x03000000);
local_write_config(PCI_BASE_ADDRESS_0, 4, PHYS_OFFSET);
local_write_config(PCI_BASE_ADDRESS_1, 4, PHYS_OFFSET + SZ_16M);
local_write_config(PCI_BASE_ADDRESS_2, 4, PHYS_OFFSET + SZ_32M);
local_write_config(PCI_BASE_ADDRESS_3, 4, PHYS_OFFSET + SZ_48M);
/*
* Enable CSR window at 0xff000000.
* Enable CSR window at 64 MiB to allow PCI masters
* to continue prefetching past 64 MiB boundary.
*/
local_write_config(PCI_BASE_ADDRESS_4, 4, 0xff000008);
local_write_config(PCI_BASE_ADDRESS_4, 4, PHYS_OFFSET + SZ_64M);
/*
* Enable the IO window to be way up high, at 0xfffffc00