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powerpc/cell: Fixed IOMMU mapping uses weak ordering for a pcie endpoint 

At the moment the fixed mapping is by default strongly ordered (the
iommu_fixed=weak boot option must be used to make the fixed mapping weakly
ordered). If we're on a setup where the southbridge is being used in
endpoint mode (triblade and CAB boards) the default should be a weakly
ordered fixed mapping.

This adds a check so that if a node of type pcie-endpoint can be found in
the device tree the fixed mapping is set to be weak by default (but can be
overridden using iommu_fixed=strong).

Signed-off-by: Mark Nelson <markn@au1.ibm.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Mark Nelson 2008-07-24 14:28:48 +10:00 committed by Benjamin Herrenschmidt
parent d6a61bfc06
commit 7886250e9d
1 changed files with 12 additions and 1 deletions
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13
arch/powerpc/platforms/cell/iommu.c
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@ -1150,12 +1150,23 @@ static int iommu_fixed_disabled;
static int __init setup_iommu_fixed(char *str) static int __init setup_iommu_fixed(char *str)
{ {
struct device_node *pciep;
if (strcmp(str, "off") == 0) if (strcmp(str, "off") == 0)
iommu_fixed_disabled = 1; iommu_fixed_disabled = 1;
else if (strcmp(str, "weak") == 0) /* If we can find a pcie-endpoint in the device tree assume that
* we're on a triblade or a CAB so by default the fixed mapping
* should be set to be weakly ordered; but only if the boot
* option WASN'T set for strong ordering
*/
pciep = of_find_node_by_type(NULL, "pcie-endpoint");
if (strcmp(str, "weak") == 0 || (pciep && strcmp(str, "strong") != 0))
iommu_fixed_is_weak = 1; iommu_fixed_is_weak = 1;
of_node_put(pciep);
return 1; return 1;
} }
__setup("iommu_fixed=", setup_iommu_fixed); __setup("iommu_fixed=", setup_iommu_fixed);