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powerpc/fsl-pci: Set relaxed ordering on prefetchable ranges

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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 <tpiepho@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
This commit is contained in:
Trent Piepho 2008-12-17 11:43:26 -08:00 committed by Kumar Gala
parent a097a78c1e
commit 565f37642c
1 changed files with 3 additions and 0 deletions
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3
arch/powerpc/sysdev/fsl_pci.c
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@ -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", pr_debug("PCI MEM resource start 0x%016llx, size 0x%016llx.\n",
(u64)res->start, (u64)size); (u64)res->start, (u64)size);
if (res->flags & IORESOURCE_PREFETCH)
flags |= 0x10000000; /* enable relaxed ordering */
for (i = 0; size > 0; i++) { for (i = 0; size > 0; i++) {
unsigned int bits = min(__ilog2(size), unsigned int bits = min(__ilog2(size),
__ffs(pci_addr | phys_addr)); __ffs(pci_addr | phys_addr));