xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

powerpc/powernv: Do not set "read" flag if direction==DMA_NONE

Browse Source 
Normally a bitmap from the iommu_table is used to track what TCE entry
is in use. Since we are going to use iommu_table without its locks and
do xchg() instead, it becomes essential not to put bits which are not
implied in the direction flag as the old TCE value (more precisely -
the permission bits) will be used to decide whether to put the page or not.

This adds iommu_direction_to_tce_perm() (its counterpart is there already)
and uses it for powernv's pnv_tce_build().

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>
This commit is contained in:
Alexey Kardashevskiy
2015-06-05 16:35:05 +10:00
committed by Michael Ellerman
parent 22af48596e
commit 10b35b2b74
3 changed files with 17 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
arch/powerpc/platforms/powernv/pci.c
View File

@@ -576,15 +576,10 @@ static int pnv_tce_build(struct iommu_table *tbl, long index, long npages,
unsigned long uaddr, enum dma_data_direction direction,
struct dma_attrs *attrs, bool rm)
{
u64 proto_tce;
u64 proto_tce = iommu_direction_to_tce_perm(direction);
__be64 *tcep, *tces;
u64 rpn;
proto_tce = TCE_PCI_READ; // Read allowed
if (direction != DMA_TO_DEVICE)
proto_tce |= TCE_PCI_WRITE;
tces = tcep = ((__be64 *)tbl->it_base) + index - tbl->it_offset;
rpn = __pa(uaddr) >> tbl->it_page_shift;