From 38192d52f159bc06b7f523800c10b583cdd661d5 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Wed, 6 Feb 2008 03:50:26 -0800 Subject: [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 --- arch/sparc64/kernel/iommu.c | 142 ++++++++------------------------------------ 1 file changed, 26 insertions(+), 116 deletions(-) (limited to 'arch/sparc64/kernel/iommu.c') diff --git a/arch/sparc64/kernel/iommu.c b/arch/sparc64/kernel/iommu.c index 4b9115a4d92e..5623a4d59dff 100644 --- a/arch/sparc64/kernel/iommu.c +++ b/arch/sparc64/kernel/iommu.c @@ -472,94 +472,15 @@ static void dma_4u_unmap_single(struct device *dev, dma_addr_t bus_addr, 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 @@ static int dma_4u_map_sg(struct device *dev, struct scatterlist *sglist, 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 @@ static int dma_4u_map_sg(struct device *dev, struct scatterlist *sglist, 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 @@ static int dma_4u_map_sg(struct device *dev, struct scatterlist *sglist, 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 @@ bad_no_ctx: static void dma_4u_unmap_sg(struct device *dev, struct scatterlist *sglist, int nelems, enum dma_data_direction direction) { - struct iommu *iommu; + unsigned long flags, ctx, i, npages; struct strbuf *strbuf; + struct iommu *iommu; iopte_t *base; - unsigned long flags, ctx, i, npages; - struct scatterlist *sg, *sgprv; u32 bus_addr; if (unlikely(direction == DMA_NONE)) { @@ -654,15 +572,7 @@ static void dma_4u_unmap_sg(struct device *dev, struct scatterlist *sglist, 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); -- cgit v1.2.3-59-g8ed1b