[SPARC64]: Temporarily remove IOMMU merging code.
Changeset fde6a3c82d67f592eb587be4d12222b0ae6d4321 ("iommu sg merging:
sparc64: make iommu respect the segment size limits") broke sparc64
because whilst it added the segment limiting code to the first pass of
SG mapping (in prepare_sg()) it did not add matching code to the
second pass handling (in fill_sg())
As a result the two passes disagree where the segment boundaries
should be, resulting in OOPSes, DMA corruption, and corrupted
superblocks.
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/arch/sparc64/kernel/iommu.c b/arch/sparc64/kernel/iommu.c
index 4b9115a..5623a4d 100644
--- a/arch/sparc64/kernel/iommu.c
+++ b/arch/sparc64/kernel/iommu.c
@@ -472,94 +472,15 @@
spin_unlock_irqrestore(&iommu->lock, flags);
}
-#define SG_ENT_PHYS_ADDRESS(SG) (__pa(sg_virt((SG))))
-
-static void fill_sg(iopte_t *iopte, struct scatterlist *sg,
- int nused, int nelems,
- unsigned long iopte_protection)
-{
- struct scatterlist *dma_sg = sg;
- int i;
-
- for (i = 0; i < nused; i++) {
- unsigned long pteval = ~0UL;
- u32 dma_npages;
-
- dma_npages = ((dma_sg->dma_address & (IO_PAGE_SIZE - 1UL)) +
- dma_sg->dma_length +
- ((IO_PAGE_SIZE - 1UL))) >> IO_PAGE_SHIFT;
- do {
- unsigned long offset;
- signed int len;
-
- /* If we are here, we know we have at least one
- * more page to map. So walk forward until we
- * hit a page crossing, and begin creating new
- * mappings from that spot.
- */
- for (;;) {
- unsigned long tmp;
-
- tmp = SG_ENT_PHYS_ADDRESS(sg);
- len = sg->length;
- if (((tmp ^ pteval) >> IO_PAGE_SHIFT) != 0UL) {
- pteval = tmp & IO_PAGE_MASK;
- offset = tmp & (IO_PAGE_SIZE - 1UL);
- break;
- }
- if (((tmp ^ (tmp + len - 1UL)) >> IO_PAGE_SHIFT) != 0UL) {
- pteval = (tmp + IO_PAGE_SIZE) & IO_PAGE_MASK;
- offset = 0UL;
- len -= (IO_PAGE_SIZE - (tmp & (IO_PAGE_SIZE - 1UL)));
- break;
- }
- sg = sg_next(sg);
- nelems--;
- }
-
- pteval = iopte_protection | (pteval & IOPTE_PAGE);
- while (len > 0) {
- *iopte++ = __iopte(pteval);
- pteval += IO_PAGE_SIZE;
- len -= (IO_PAGE_SIZE - offset);
- offset = 0;
- dma_npages--;
- }
-
- pteval = (pteval & IOPTE_PAGE) + len;
- sg = sg_next(sg);
- nelems--;
-
- /* Skip over any tail mappings we've fully mapped,
- * adjusting pteval along the way. Stop when we
- * detect a page crossing event.
- */
- while (nelems &&
- (pteval << (64 - IO_PAGE_SHIFT)) != 0UL &&
- (pteval == SG_ENT_PHYS_ADDRESS(sg)) &&
- ((pteval ^
- (SG_ENT_PHYS_ADDRESS(sg) + sg->length - 1UL)) >> IO_PAGE_SHIFT) == 0UL) {
- pteval += sg->length;
- sg = sg_next(sg);
- nelems--;
- }
- if ((pteval << (64 - IO_PAGE_SHIFT)) == 0UL)
- pteval = ~0UL;
- } while (dma_npages != 0);
- dma_sg = sg_next(dma_sg);
- }
-}
-
static int dma_4u_map_sg(struct device *dev, struct scatterlist *sglist,
int nelems, enum dma_data_direction direction)
{
- struct iommu *iommu;
+ unsigned long flags, ctx, i, npages, iopte_protection;
+ struct scatterlist *sg;
struct strbuf *strbuf;
- unsigned long flags, ctx, npages, iopte_protection;
+ struct iommu *iommu;
iopte_t *base;
u32 dma_base;
- struct scatterlist *sgtmp;
- int used;
/* Fast path single entry scatterlists. */
if (nelems == 1) {
@@ -578,11 +499,7 @@
if (unlikely(direction == DMA_NONE))
goto bad_no_ctx;
- /* Step 1: Prepare scatter list. */
-
- npages = prepare_sg(dev, sglist, nelems);
-
- /* Step 2: Allocate a cluster and context, if necessary. */
+ npages = calc_npages(sglist, nelems);
spin_lock_irqsave(&iommu->lock, flags);
@@ -599,18 +516,6 @@
dma_base = iommu->page_table_map_base +
((base - iommu->page_table) << IO_PAGE_SHIFT);
- /* Step 3: Normalize DMA addresses. */
- used = nelems;
-
- sgtmp = sglist;
- while (used && sgtmp->dma_length) {
- sgtmp->dma_address += dma_base;
- sgtmp = sg_next(sgtmp);
- used--;
- }
- used = nelems - used;
-
- /* Step 4: Create the mappings. */
if (strbuf->strbuf_enabled)
iopte_protection = IOPTE_STREAMING(ctx);
else
@@ -618,13 +523,27 @@
if (direction != DMA_TO_DEVICE)
iopte_protection |= IOPTE_WRITE;
- fill_sg(base, sglist, used, nelems, iopte_protection);
+ for_each_sg(sglist, sg, nelems, i) {
+ unsigned long paddr = SG_ENT_PHYS_ADDRESS(sg);
+ unsigned long slen = sg->length;
+ unsigned long this_npages;
-#ifdef VERIFY_SG
- verify_sglist(sglist, nelems, base, npages);
-#endif
+ this_npages = iommu_num_pages(paddr, slen);
- return used;
+ sg->dma_address = dma_base | (paddr & ~IO_PAGE_MASK);
+ sg->dma_length = slen;
+
+ paddr &= IO_PAGE_MASK;
+ while (this_npages--) {
+ iopte_val(*base) = iopte_protection | paddr;
+
+ base++;
+ paddr += IO_PAGE_SIZE;
+ dma_base += IO_PAGE_SIZE;
+ }
+ }
+
+ return nelems;
bad:
iommu_free_ctx(iommu, ctx);
@@ -637,11 +556,10 @@
static void dma_4u_unmap_sg(struct device *dev, struct scatterlist *sglist,
int nelems, enum dma_data_direction direction)
{
- struct iommu *iommu;
- struct strbuf *strbuf;
- iopte_t *base;
unsigned long flags, ctx, i, npages;
- struct scatterlist *sg, *sgprv;
+ struct strbuf *strbuf;
+ struct iommu *iommu;
+ iopte_t *base;
u32 bus_addr;
if (unlikely(direction == DMA_NONE)) {
@@ -654,15 +572,7 @@
bus_addr = sglist->dma_address & IO_PAGE_MASK;
- sgprv = NULL;
- for_each_sg(sglist, sg, nelems, i) {
- if (sg->dma_length == 0)
- break;
- sgprv = sg;
- }
-
- npages = (IO_PAGE_ALIGN(sgprv->dma_address + sgprv->dma_length) -
- bus_addr) >> IO_PAGE_SHIFT;
+ npages = calc_npages(sglist, nelems);
base = iommu->page_table +
((bus_addr - iommu->page_table_map_base) >> IO_PAGE_SHIFT);