aboutsummaryrefslogtreecommitdiff
path: root/lib/swiotlb.c
diff options
context:
space:
mode:
authorJan Beulich <JBeulich@suse.com>2014-06-02 14:58:25 +0100
committerKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2014-06-20 16:04:32 -0400
commit8e0629c1d4ce86ce7d98ca8756f42769bb17a3c8 (patch)
tree3b82fe0fc81f5d2671bf3a33667422e1f36ea93e /lib/swiotlb.c
parent7171511eaec5bf23fb06078f59784a3a0626b38f (diff)
downloadlinux-linaro-stable-8e0629c1d4ce86ce7d98ca8756f42769bb17a3c8.tar.gz
swiotlb: don't assume PA 0 is invalid
In 2.6.29 io_tlb_orig_addr[] got converted from storing virtual addresses to storing physical ones. While checking virtual addresses against NULL is a legitimate thing to catch invalid entries, checking physical ones against zero isn't: There's no guarantee that PFN 0 is reserved on a particular platform. Since it is unclear whether the check in swiotlb_tbl_unmap_single() is actually needed, retain it but check against a guaranteed invalid physical address. This requires setting up the array in a suitable fashion. And since the original code failed to invalidate array entries when regions get unmapped, this is being fixed at once along with adding a similar check to swiotlb_tbl_sync_single(). Obviously the less intrusive change would be to simply drop the check in swiotlb_tbl_unmap_single(). Signed-off-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'lib/swiotlb.c')
-rw-r--r--lib/swiotlb.c28
1 files changed, 18 insertions, 10 deletions
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index 649d097853a1..4abda074ea45 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -86,6 +86,7 @@ static unsigned int io_tlb_index;
* We need to save away the original address corresponding to a mapped entry
* for the sync operations.
*/
+#define INVALID_PHYS_ADDR (~(phys_addr_t)0)
static phys_addr_t *io_tlb_orig_addr;
/*
@@ -188,12 +189,14 @@ int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
io_tlb_list = memblock_virt_alloc(
PAGE_ALIGN(io_tlb_nslabs * sizeof(int)),
PAGE_SIZE);
- for (i = 0; i < io_tlb_nslabs; i++)
- io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE);
- io_tlb_index = 0;
io_tlb_orig_addr = memblock_virt_alloc(
PAGE_ALIGN(io_tlb_nslabs * sizeof(phys_addr_t)),
PAGE_SIZE);
+ for (i = 0; i < io_tlb_nslabs; i++) {
+ io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE);
+ io_tlb_orig_addr[i] = INVALID_PHYS_ADDR;
+ }
+ io_tlb_index = 0;
if (verbose)
swiotlb_print_info();
@@ -313,10 +316,6 @@ swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs)
if (!io_tlb_list)
goto cleanup3;
- for (i = 0; i < io_tlb_nslabs; i++)
- io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE);
- io_tlb_index = 0;
-
io_tlb_orig_addr = (phys_addr_t *)
__get_free_pages(GFP_KERNEL,
get_order(io_tlb_nslabs *
@@ -324,7 +323,11 @@ swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs)
if (!io_tlb_orig_addr)
goto cleanup4;
- memset(io_tlb_orig_addr, 0, io_tlb_nslabs * sizeof(phys_addr_t));
+ for (i = 0; i < io_tlb_nslabs; i++) {
+ io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE);
+ io_tlb_orig_addr[i] = INVALID_PHYS_ADDR;
+ }
+ io_tlb_index = 0;
swiotlb_print_info();
@@ -556,7 +559,8 @@ void swiotlb_tbl_unmap_single(struct device *hwdev, phys_addr_t tlb_addr,
/*
* First, sync the memory before unmapping the entry
*/
- if (orig_addr && ((dir == DMA_FROM_DEVICE) || (dir == DMA_BIDIRECTIONAL)))
+ if (orig_addr != INVALID_PHYS_ADDR &&
+ ((dir == DMA_FROM_DEVICE) || (dir == DMA_BIDIRECTIONAL)))
swiotlb_bounce(orig_addr, tlb_addr, size, DMA_FROM_DEVICE);
/*
@@ -573,8 +577,10 @@ void swiotlb_tbl_unmap_single(struct device *hwdev, phys_addr_t tlb_addr,
* Step 1: return the slots to the free list, merging the
* slots with superceeding slots
*/
- for (i = index + nslots - 1; i >= index; i--)
+ for (i = index + nslots - 1; i >= index; i--) {
io_tlb_list[i] = ++count;
+ io_tlb_orig_addr[i] = INVALID_PHYS_ADDR;
+ }
/*
* Step 2: merge the returned slots with the preceding slots,
* if available (non zero)
@@ -593,6 +599,8 @@ void swiotlb_tbl_sync_single(struct device *hwdev, phys_addr_t tlb_addr,
int index = (tlb_addr - io_tlb_start) >> IO_TLB_SHIFT;
phys_addr_t orig_addr = io_tlb_orig_addr[index];
+ if (orig_addr == INVALID_PHYS_ADDR)
+ return;
orig_addr += (unsigned long)tlb_addr & ((1 << IO_TLB_SHIFT) - 1);
switch (target) {