s390/pci_dma: unify label of invalid translation table entries

Newly allocated translation table entries are flagged as invalid
and protected. If an existing translation table entry is invalidated,
the protection flag is left unchanged.

If a page (with invalid and protection flag set) is accessed it's
undefined which type of exception we'll receive.

Make sure to always set the invalid flag only.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 3 insertions, 4 deletions

diff --git a/arch/s390/pci/pci_dma.c b/arch/s390/pci/pci_dma.c
index 37d10f74425a..e4a3a31fd59a 100644
--- a/arch/s390/pci/pci_dma.c
+++ b/arch/s390/pci/pci_dma.c
@@ -33,7 +33,7 @@ unsigned long *dma_alloc_cpu_table(void)
                 return NULL;
 
         for (entry = table; entry < table + ZPCI_TABLE_ENTRIES; entry++)
-                *entry = ZPCI_TABLE_INVALID | ZPCI_TABLE_PROTECTED;
+                *entry = ZPCI_TABLE_INVALID;
         return table;
 }
 
@@ -51,7 +51,7 @@ static unsigned long *dma_alloc_page_table(void)
                 return NULL;
 
         for (entry = table; entry < table + ZPCI_PT_ENTRIES; entry++)
-                *entry = ZPCI_PTE_INVALID | ZPCI_TABLE_PROTECTED;
+                *entry = ZPCI_PTE_INVALID;
         return table;
 }
 
@@ -127,7 +127,6 @@ void dma_update_cpu_trans(unsigned long *dma_table, void *page_addr,
 
         if (flags & ZPCI_PTE_INVALID) {
                 invalidate_pt_entry(entry);
-                return;
         } else {
                 set_pt_pfaa(entry, page_addr);
                 validate_pt_entry(entry);
@@ -311,7 +310,7 @@ static void s390_dma_unmap_pages(struct device *dev, dma_addr_t dma_addr,
         npages = iommu_num_pages(dma_addr, size, PAGE_SIZE);
         dma_addr = dma_addr & PAGE_MASK;
         if (dma_update_trans(zdev, 0, dma_addr, npages * PAGE_SIZE,
-                             ZPCI_TABLE_PROTECTED | ZPCI_PTE_INVALID)) {
+                             ZPCI_PTE_INVALID)) {
                 zpci_err("unmap error:\n");
                 zpci_err_hex(&dma_addr, sizeof(dma_addr));
         }