[PATCH kernel v9 17/32] powerpc/powernv: Implement accessor to TCE entry

Alexey Kardashevskiy
2015-04-25T12:22:52Z

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>
---
Changes:
v9:
* new patch in the series to separate this mechanical change from
functional changes; this is not right before
"powerpc/powernv: Implement multilevel TCE tables" but here in order
to let the next patch - "powerpc/iommu/powernv: Release replaced TCE" -
use pnv_tce() and avoid changing the same code twice
---
arch/powerpc/platforms/powernv/pci.c | 34 +++++++++++++++++++++-------------
1 file changed, 21 insertions(+), 13 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/pci.c b/arch/powerpc/platforms/powernv/pci.c
index 84b4ea4..ba75aa5 100644
--- 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;
+ u64 rpn = __pa(uaddr) >> tbl->it_page_shift;
+ long i;

- tcep = ((__be64 *)tbl->it_base) + index - tbl->it_offset;
- rpn = __pa(uaddr) >> tbl->it_page_shift;
-
- 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));
}

void pnv_pci_setup_iommu_table(struct iommu_table *tbl,
--
2.0.0