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[/] [or1k_soc_on_altera_embedded_dev_kit/] [trunk/] [linux-2.6/] [linux-2.6.24/] [arch/] [sparc64/] [kernel/] [iommu_common.c] - Rev 3
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/* $Id: iommu_common.c,v 1.9 2001/12/17 07:05:09 davem Exp $ * iommu_common.c: UltraSparc SBUS/PCI common iommu code. * * Copyright (C) 1999 David S. Miller (davem@redhat.com) */ #include "iommu_common.h" /* You are _strongly_ advised to enable the following debugging code * any time you make changes to the sg code below, run it for a while * with filesystems mounted read-only before buying the farm... -DaveM */ #ifdef VERIFY_SG static int verify_lengths(struct scatterlist *sglist, int nents, int npages) { int sg_len, dma_len; int i, pgcount; struct scatterlist *sg; sg_len = 0; for_each_sg(sglist, sg, nents, i) sg_len += sg->length; dma_len = 0; for_each_sg(sglist, sg, nents, i) { if (!sg->dma_length) break; dma_len += sg->dma_length; } if (sg_len != dma_len) { printk("verify_lengths: Error, different, sg[%d] dma[%d]\n", sg_len, dma_len); return -1; } pgcount = 0; for_each_sg(sglist, sg, nents, i) { unsigned long start, end; if (!sg->dma_length) break; start = sg->dma_address; start = start & IO_PAGE_MASK; end = sg->dma_address + sg->dma_length; end = (end + (IO_PAGE_SIZE - 1)) & IO_PAGE_MASK; pgcount += ((end - start) >> IO_PAGE_SHIFT); } if (pgcount != npages) { printk("verify_lengths: Error, page count wrong, " "npages[%d] pgcount[%d]\n", npages, pgcount); return -1; } /* This test passes... */ return 0; } static int verify_one_map(struct scatterlist *dma_sg, struct scatterlist **__sg, int nents, iopte_t **__iopte) { struct scatterlist *sg = *__sg; iopte_t *iopte = *__iopte; u32 dlen = dma_sg->dma_length; u32 daddr; unsigned int sglen; unsigned long sgaddr; daddr = dma_sg->dma_address; sglen = sg->length; sgaddr = (unsigned long) sg_virt(sg); while (dlen > 0) { unsigned long paddr; /* SG and DMA_SG must begin at the same sub-page boundary. */ if ((sgaddr & ~IO_PAGE_MASK) != (daddr & ~IO_PAGE_MASK)) { printk("verify_one_map: Wrong start offset " "sg[%08lx] dma[%08x]\n", sgaddr, daddr); nents = -1; goto out; } /* Verify the IOPTE points to the right page. */ paddr = iopte_val(*iopte) & IOPTE_PAGE; if ((paddr + PAGE_OFFSET) != (sgaddr & IO_PAGE_MASK)) { printk("verify_one_map: IOPTE[%08lx] maps the " "wrong page, should be [%08lx]\n", iopte_val(*iopte), (sgaddr & IO_PAGE_MASK) - PAGE_OFFSET); nents = -1; goto out; } /* If this SG crosses a page, adjust to that next page * boundary and loop. */ if ((sgaddr & IO_PAGE_MASK) ^ ((sgaddr + sglen - 1) & IO_PAGE_MASK)) { unsigned long next_page, diff; next_page = (sgaddr + IO_PAGE_SIZE) & IO_PAGE_MASK; diff = next_page - sgaddr; sgaddr += diff; daddr += diff; sglen -= diff; dlen -= diff; if (dlen > 0) iopte++; continue; } /* SG wholly consumed within this page. */ daddr += sglen; dlen -= sglen; if (dlen > 0 && ((daddr & ~IO_PAGE_MASK) == 0)) iopte++; sg = sg_next(sg); if (--nents <= 0) break; sgaddr = (unsigned long) sg_virt(sg); sglen = sg->length; } if (dlen < 0) { /* Transfer overrun, big problems. */ printk("verify_one_map: Transfer overrun by %d bytes.\n", -dlen); nents = -1; } else { /* Advance to next dma_sg implies that the next iopte will * begin it. */ iopte++; } out: *__sg = sg; *__iopte = iopte; return nents; } static int verify_maps(struct scatterlist *sg, int nents, iopte_t *iopte) { struct scatterlist *dma_sg = sg; struct scatterlist *orig_dma_sg = dma_sg; int orig_nents = nents; for (;;) { nents = verify_one_map(dma_sg, &sg, nents, &iopte); if (nents <= 0) break; dma_sg = sg_next(dma_sg); if (dma_sg->dma_length == 0) break; } if (nents > 0) { printk("verify_maps: dma maps consumed by some sgs remain (%d)\n", nents); return -1; } if (nents < 0) { printk("verify_maps: Error, messed up mappings, " "at sg %d dma_sg %d\n", (int) (orig_nents + nents), (int) (dma_sg - orig_dma_sg)); return -1; } /* This test passes... */ return 0; } void verify_sglist(struct scatterlist *sglist, int nents, iopte_t *iopte, int npages) { struct scatterlist *sg; if (verify_lengths(sglist, nents, npages) < 0 || verify_maps(sglist, nents, iopte) < 0) { int i; printk("verify_sglist: Crap, messed up mappings, dumping, iodma at "); printk("%016lx.\n", sglist->dma_address & IO_PAGE_MASK); for_each_sg(sglist, sg, nents, i) { printk("sg(%d): page_addr(%p) off(%x) length(%x) " "dma_address[%016x] dma_length[%016x]\n", i, page_address(sg_page(sg)), sg->offset, sg->length, sg->dma_address, sg->dma_length); } } /* Seems to be ok */ } #endif unsigned long prepare_sg(struct scatterlist *sg, int nents) { struct scatterlist *dma_sg = sg; unsigned long prev; u32 dent_addr, dent_len; prev = (unsigned long) sg_virt(sg); prev += (unsigned long) (dent_len = sg->length); dent_addr = (u32) ((unsigned long)(sg_virt(sg)) & (IO_PAGE_SIZE - 1UL)); while (--nents) { unsigned long addr; sg = sg_next(sg); addr = (unsigned long) sg_virt(sg); if (! VCONTIG(prev, addr)) { dma_sg->dma_address = dent_addr; dma_sg->dma_length = dent_len; dma_sg = sg_next(dma_sg); dent_addr = ((dent_addr + dent_len + (IO_PAGE_SIZE - 1UL)) >> IO_PAGE_SHIFT); dent_addr <<= IO_PAGE_SHIFT; dent_addr += addr & (IO_PAGE_SIZE - 1UL); dent_len = 0; } dent_len += sg->length; prev = addr + sg->length; } dma_sg->dma_address = dent_addr; dma_sg->dma_length = dent_len; if (dma_sg != sg) { dma_sg = sg_next(dma_sg); dma_sg->dma_length = 0; } return ((unsigned long) dent_addr + (unsigned long) dent_len + (IO_PAGE_SIZE - 1UL)) >> IO_PAGE_SHIFT; }