From 7886250e9d71b24d0205ac6798ee855fb3836318 Mon Sep 17 00:00:00 2001 From: Mark Nelson Date: Thu, 24 Jul 2008 14:28:48 +1000 Subject: [PATCH] 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 Acked-by: Arnd Bergmann Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/platforms/cell/iommu.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/platforms/cell/iommu.c b/arch/powerpc/platforms/cell/iommu.c index 208005ca262..031124a8e37 100644 --- a/arch/powerpc/platforms/cell/iommu.c +++ b/arch/powerpc/platforms/cell/iommu.c @@ -1150,12 +1150,23 @@ static int iommu_fixed_disabled; static int __init setup_iommu_fixed(char *str) { + struct device_node *pciep; + if (strcmp(str, "off") == 0) 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; + of_node_put(pciep); + return 1; } __setup("iommu_fixed=", setup_iommu_fixed); -- 2.41.1