From 0a07232ff62d1523c5fa7292180890f4de670b95 Mon Sep 17 00:00:00 2001 From: Krzysztof Hałasa Date: Fri, 13 Mar 2009 17:57:04 +0100 Subject: IXP4xx: workaround for PCI prefetch problems near 64 MB boundary. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 --- arch/arm/include/asm/sizes.h | 1 + arch/arm/mach-ixp4xx/common-pci.c | 23 ++++++++++++----------- 2 files changed, 13 insertions(+), 11 deletions(-) (limited to 'arch') diff --git a/arch/arm/include/asm/sizes.h b/arch/arm/include/asm/sizes.h index 503843db1565..c10d1aa4b487 100644 --- a/arch/arm/include/asm/sizes.h +++ b/arch/arm/include/asm/sizes.h @@ -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 diff --git a/arch/arm/mach-ixp4xx/common-pci.c b/arch/arm/mach-ixp4xx/common-pci.c index d816c51320c7..2d0f09e9819d 100644 --- a/arch/arm/mach-ixp4xx/common-pci.c +++ b/arch/arm/mach-ixp4xx/common-pci.c @@ -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 -- cgit v1.2.3