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authorAlexey Kardashevskiy <aik@ozlabs.ru>2017-03-22 15:21:48 +1100
committerMichael Ellerman <mpe@ellerman.id.au>2017-03-30 21:42:01 +1100
commita540aa56ba3d29084f28710c8b93cc9c3c422943 (patch)
tree265e8987fb9f37ede5fb9175dac3e26b62745ed8 /arch/powerpc/kernel/iommu.c
parent6b5c19c55266f6efd10ffac0e9f9f2b7aa420a58 (diff)
downloadlinux-a540aa56ba3d29084f28710c8b93cc9c3c422943.tar.bz2
powerpc/powernv/iommu: Add real mode version of iommu_table_ops::exchange()
In real mode, TCE tables are invalidated using special cache-inhibited store instructions which are not available in virtual mode This defines and implements exchange_rm() callback. This does not define set_rm/clear_rm/flush_rm callbacks as there is no user for those - exchange/exchange_rm are only to be used by KVM for VFIO. The exchange_rm callback is defined for IODA1/IODA2 powernv platforms. This replaces list_for_each_entry_rcu with its lockless version as from now on pnv_pci_ioda2_tce_invalidate() can be called in the real mode too. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/kernel/iommu.c')
-rw-r--r--arch/powerpc/kernel/iommu.c25
1 files changed, 25 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index 5f202a566ec5..685a4767b722 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c
@@ -1004,6 +1004,31 @@ long iommu_tce_xchg(struct iommu_table *tbl, unsigned long entry,
}
EXPORT_SYMBOL_GPL(iommu_tce_xchg);
+#ifdef CONFIG_PPC_BOOK3S_64
+long iommu_tce_xchg_rm(struct iommu_table *tbl, unsigned long entry,
+ unsigned long *hpa, enum dma_data_direction *direction)
+{
+ long ret;
+
+ ret = tbl->it_ops->exchange_rm(tbl, entry, hpa, direction);
+
+ if (!ret && ((*direction == DMA_FROM_DEVICE) ||
+ (*direction == DMA_BIDIRECTIONAL))) {
+ struct page *pg = realmode_pfn_to_page(*hpa >> PAGE_SHIFT);
+
+ if (likely(pg)) {
+ SetPageDirty(pg);
+ } else {
+ tbl->it_ops->exchange_rm(tbl, entry, hpa, direction);
+ ret = -EFAULT;
+ }
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(iommu_tce_xchg_rm);
+#endif
+
int iommu_take_ownership(struct iommu_table *tbl)
{
unsigned long flags, i, sz = (tbl->it_size + 7) >> 3;