The IOMMU page size is not always stored in struct iommu on Power.
Specifically if a device is configured for DDW (Dynamic DMA Windows aka.
64-bit direct DMA), the used TCE (Translation Control Entry) size is
stored in a special device property created at run-time by the DDW
configuration code. DDW is a pseries-specific feature, so allow
platforms to override the implementation of dma_get_page_shift if
desired.
Signed-off-by: Nishanth Aravamudan <n...@linux.vnet.ibm.com>
diff --git a/arch/powerpc/include/asm/machdep.h
b/arch/powerpc/include/asm/machdep.h
index cab6753..5c372e3 100644
--- a/arch/powerpc/include/asm/machdep.h
+++ b/arch/powerpc/include/asm/machdep.h
@@ -78,9 +78,10 @@ struct machdep_calls {
#endif
#endif /* CONFIG_PPC64 */
- /* Platform set_dma_mask and dma_get_required_mask overrides */
+ /* Platform overrides */
int (*dma_set_mask)(struct device *dev, u64 dma_mask);
u64 (*dma_get_required_mask)(struct device *dev);
+ unsigned long (*dma_get_page_shift)(struct device *dev);
int (*probe)(void);
void (*setup_arch)(void); /* Optional, may be NULL */
diff --git a/arch/powerpc/kernel/dma.c b/arch/powerpc/kernel/dma.c
index e805af2..c363896 100644
--- a/arch/powerpc/kernel/dma.c
+++ b/arch/powerpc/kernel/dma.c
@@ -338,6 +338,8 @@ EXPORT_SYMBOL(dma_set_mask);
unsigned long dma_get_page_shift(struct device *dev)
{
struct iommu_table *tbl = get_iommu_table_base(dev);
+ if (ppc_md.dma_get_page_shift)
+ return ppc_md.dma_get_page_shift(dev);
if (tbl)
return tbl->it_page_shift;
return PAGE_SHIFT;
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