Merge tag 'stable/for-linus-3.16-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb
Pull swiotlb bugfix from Konrad Rzeszutek Wilk:
"One bug-fix that had been in tree for quite some time. We had assumed
that the physical address zero was invalid and would fail it. But
that is not true and on some architectures it is not reserved and
valid. This fixes it"
* tag 'stable/for-linus-3.16-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb:
swiotlb: don't assume PA 0 is invalid
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index 649d097..4abda07 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -86,6 +86,7 @@
* 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 @@
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 @@
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 @@
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 @@
/*
* 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 @@
* 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 @@
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) {