From 6a5c7be5e484bda5b2639fedf7dbe3f25c15c962 Mon Sep 17 00:00:00 2001 From: Milton Miller Date: Fri, 24 Jun 2011 09:05:22 +0000 Subject: powerpc: Override dma_get_required_mask by platform hook and ops The hook dma_get_required_mask is supposed to return the mask required by the platform to operate efficently. The generic version of dma_get_required_mask in driver/base/platform.c returns a mask based only on max_pfn. However, this is likely too big for iommu systems and could be too small for platforms that require a dma offset or have a secondary window at a high offset. Override the default, provide a hook in ppc_md used by pseries lpar and cell, and provide the default answer based on memblock_end_of_DRAM(), with hooks for get_dma_offset, and provide an implementation for iommu that looks at the defined table size. Coverting from the end address to the required bit mask is based on the generic implementation. The need for this was discovered when the qla2xxx driver switched to 64 bit dma then reverted to 32 bit when dma_get_required_mask said 32 bits was sufficient. Signed-off-by: Milton Miller Signed-off-by: Nishanth Aravamudan Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-kernel@vger.kernel.org Cc: benh@kernel.crashing.org Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/platforms/pseries/iommu.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) (limited to 'arch/powerpc/platforms/pseries') diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c index 01faab9456ca..fe5ededf0d60 100644 --- a/arch/powerpc/platforms/pseries/iommu.c +++ b/arch/powerpc/platforms/pseries/iommu.c @@ -1077,12 +1077,38 @@ check_mask: return 0; } +static u64 dma_get_required_mask_pSeriesLP(struct device *dev) +{ + if (!dev->dma_mask) + return 0; + + if (!disable_ddw && dev_is_pci(dev)) { + struct pci_dev *pdev = to_pci_dev(dev); + struct device_node *dn; + + dn = pci_device_to_OF_node(pdev); + + /* search upwards for ibm,dma-window */ + for (; dn && PCI_DN(dn) && !PCI_DN(dn)->iommu_table; + dn = dn->parent) + if (of_get_property(dn, "ibm,dma-window", NULL)) + break; + /* if there is a ibm,ddw-applicable property require 64 bits */ + if (dn && PCI_DN(dn) && + of_get_property(dn, "ibm,ddw-applicable", NULL)) + return DMA_BIT_MASK(64); + } + + return dma_iommu_get_required_mask(dev); +} + #else /* CONFIG_PCI */ #define pci_dma_bus_setup_pSeries NULL #define pci_dma_dev_setup_pSeries NULL #define pci_dma_bus_setup_pSeriesLP NULL #define pci_dma_dev_setup_pSeriesLP NULL #define dma_set_mask_pSeriesLP NULL +#define dma_get_required_mask_pSeriesLP NULL #endif /* !CONFIG_PCI */ static int iommu_mem_notifier(struct notifier_block *nb, unsigned long action, @@ -1186,6 +1212,7 @@ void iommu_init_early_pSeries(void) ppc_md.pci_dma_bus_setup = pci_dma_bus_setup_pSeriesLP; ppc_md.pci_dma_dev_setup = pci_dma_dev_setup_pSeriesLP; ppc_md.dma_set_mask = dma_set_mask_pSeriesLP; + ppc_md.dma_get_required_mask = dma_get_required_mask_pSeriesLP; } else { ppc_md.tce_build = tce_build_pSeries; ppc_md.tce_free = tce_free_pSeries; -- cgit v1.2.3