powerpc/powernv: Implement accessor to TCE entry

This replaces direct accesses to TCE table with a helper which
returns an TCE entry address. This does not make difference now but will
when multi-level TCE tables get introduces.

No change in behavior is expected.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/platforms/powernv/pci.c b/arch/powerpc/platforms/powernv/pci.c
index 00f1abd343799a202e88a9886cf86e3fe360912b..a07b83283ccc461c8e5a9363c3545997f9afaac1 100644 (file)
--- a/arch/powerpc/platforms/powernv/pci.c
+++ b/arch/powerpc/platforms/powernv/pci.c
@@ -572,38 +572,46 @@ struct pci_ops pnv_pci_ops = {
        .write = pnv_pci_write_config,
 };
 
+static __be64 *pnv_tce(struct iommu_table *tbl, long idx)
+{
+       __be64 *tmp = ((__be64 *)tbl->it_base);
+
+       return tmp + idx;
+}
+
 int pnv_tce_build(struct iommu_table *tbl, long index, long npages,
                unsigned long uaddr, enum dma_data_direction direction,
                struct dma_attrs *attrs)
 {
        u64 proto_tce = iommu_direction_to_tce_perm(direction);
-       __be64 *tcep;
-       u64 rpn;
-
-       tcep = ((__be64 *)tbl->it_base) + index - tbl->it_offset;
-       rpn = __pa(uaddr) >> tbl->it_page_shift;
+       u64 rpn = __pa(uaddr) >> tbl->it_page_shift;
+       long i;
 
-       while (npages--)
-               *(tcep++) = cpu_to_be64(proto_tce |
-                               (rpn++ << tbl->it_page_shift));
+       for (i = 0; i < npages; i++) {
+               unsigned long newtce = proto_tce |
+                       ((rpn + i) << tbl->it_page_shift);
+               unsigned long idx = index - tbl->it_offset + i;
 
+               *(pnv_tce(tbl, idx)) = cpu_to_be64(newtce);
+       }
 
        return 0;
 }
 
 void pnv_tce_free(struct iommu_table *tbl, long index, long npages)
 {
-       __be64 *tcep;
+       long i;
 
-       tcep = ((__be64 *)tbl->it_base) + index - tbl->it_offset;
+       for (i = 0; i < npages; i++) {
+               unsigned long idx = index - tbl->it_offset + i;
 
-       while (npages--)
-               *(tcep++) = cpu_to_be64(0);
+               *(pnv_tce(tbl, idx)) = cpu_to_be64(0);
+       }
 }
 
 unsigned long pnv_tce_get(struct iommu_table *tbl, long index)
 {
-       return ((u64 *)tbl->it_base)[index - tbl->it_offset];
+       return *(pnv_tce(tbl, index - tbl->it_offset));
 }
 
 struct iommu_table *pnv_pci_table_alloc(int nid)