1 files changed, 231 insertions, 0 deletions

diff --git a/arch/sparc64/kernel/iommu_common.c b/arch/sparc64/kernel/iommu_common.c
new file mode 100644
index 000000000000..12c93a3eee26
--- /dev/null
+++ b/arch/sparc64/kernel/iommu_common.c
@@ -0,0 +1,231 @@
+/* $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 *sg, int nents, int npages)
+{
+        int sg_len, dma_len;
+        int i, pgcount;
+
+        sg_len = 0;
+        for (i = 0; i < nents; i++)
+                sg_len += sg[i].length;
+
+        dma_len = 0;
+        for (i = 0; i < nents && sg[i].dma_length; i++)
+                dma_len += sg[i].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 (i = 0; i < nents && sg[i].dma_length; i++) {
+                unsigned long start, end;
+
+                start = sg[i].dma_address;
+                start = start & IO_PAGE_MASK;
+
+                end = sg[i].dma_address + sg[i].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) (page_address(sg->page) + sg->offset);
+        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++;
+                if (--nents <= 0)
+                        break;
+                sgaddr = (unsigned long) (page_address(sg->page) + sg->offset);
+                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++;
+                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 *sg, int nents, iopte_t *iopte, int npages)
+{
+        if (verify_lengths(sg, nents, npages) < 0 ||
+            verify_maps(sg, nents, iopte) < 0) {
+                int i;
+
+                printk("verify_sglist: Crap, messed up mappings, dumping, iodma at ");
+                printk("%016lx.\n", sg->dma_address & IO_PAGE_MASK);
+
+                for (i = 0; i < nents; i++) {
+                        printk("sg(%d): page_addr(%p) off(%x) length(%x) "
+                               "dma_address[%016lx] dma_length[%016lx]\n",
+                               i,
+                               page_address(sg[i].page), sg[i].offset,
+                               sg[i].length,
+                               sg[i].dma_address, sg[i].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) (page_address(sg->page) + sg->offset);
+        prev += (unsigned long) (dent_len = sg->length);
+        dent_addr = (u32) ((unsigned long)(page_address(sg->page) + sg->offset)
+                           & (IO_PAGE_SIZE - 1UL));
+        while (--nents) {
+                unsigned long addr;
+
+                sg++;
+                addr = (unsigned long) (page_address(sg->page) + sg->offset);
+                if (! VCONTIG(prev, addr)) {
+                        dma_sg->dma_address = dent_addr;
+                        dma_sg->dma_length = dent_len;
+                        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;
+
+        return ((unsigned long) dent_addr +
+                (unsigned long) dent_len +
+                (IO_PAGE_SIZE - 1UL)) >> IO_PAGE_SHIFT;
+}