From 565f37642c78754a85efe6c20a4a15e18ed21f07 Mon Sep 17 00:00:00 2001 From: Trent Piepho Date: Wed, 17 Dec 2008 11:43:26 -0800 Subject: [PATCH] powerpc/fsl-pci: Set relaxed ordering on prefetchable ranges Provides a small speedup when accessing pefetchable ranges. To indicate that a memory range is prefetchable, mark it in the dts file with 42000000 instead of 02000000. A powepc pci_controller is allowed three memory ranges, any of which may be prefetchable. However, the PCI-PCI bridge configuration space only has one field for "non-prefetchable memory behind bridge", which has a 32 bit address, and one field for "prefetchable memory behind bridge", which may have a 64 bit address. These are PCI bus addresses, not CPU physical addresses. So really you're only allowed one memory range of each type. And if you want the range at a PCI address above 32 bits you must make it prefetchable. Signed-off-by: Trent Piepho Signed-off-by: Kumar Gala --- arch/powerpc/sysdev/fsl_pci.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/powerpc/sysdev/fsl_pci.c b/arch/powerpc/sysdev/fsl_pci.c index 44bc903ead74..9817f63723dd 100644 --- a/arch/powerpc/sysdev/fsl_pci.c +++ b/arch/powerpc/sysdev/fsl_pci.c @@ -41,6 +41,9 @@ static int __init setup_one_atmu(struct ccsr_pci __iomem *pci, pr_debug("PCI MEM resource start 0x%016llx, size 0x%016llx.\n", (u64)res->start, (u64)size); + if (res->flags & IORESOURCE_PREFETCH) + flags |= 0x10000000; /* enable relaxed ordering */ + for (i = 0; size > 0; i++) { unsigned int bits = min(__ilog2(size), __ffs(pci_addr | phys_addr));