Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 171 insertions, 0 deletions

diff --git a/drivers/parisc/iommu-helpers.h b/drivers/parisc/iommu-helpers.h
new file mode 100644
index 000000000000..38d9e1aba1d0
--- /dev/null
+++ b/drivers/parisc/iommu-helpers.h
@@ -0,0 +1,171 @@
+/**
+ * iommu_fill_pdir - Insert coalesced scatter/gather chunks into the I/O Pdir.
+ * @ioc: The I/O Controller.
+ * @startsg: The scatter/gather list of coalesced chunks.
+ * @nents: The number of entries in the scatter/gather list.
+ * @hint: The DMA Hint.
+ *
+ * This function inserts the coalesced scatter/gather list chunks into the
+ * I/O Controller's I/O Pdir.
+ */ 
+static inline unsigned int
+iommu_fill_pdir(struct ioc *ioc, struct scatterlist *startsg, int nents, 
+                unsigned long hint,
+                void (*iommu_io_pdir_entry)(u64 *, space_t, unsigned long,
+                                            unsigned long))
+{
+        struct scatterlist *dma_sg = startsg;   /* pointer to current DMA */
+        unsigned int n_mappings = 0;
+        unsigned long dma_offset = 0, dma_len = 0;
+        u64 *pdirp = NULL;
+
+        /* Horrible hack.  For efficiency's sake, dma_sg starts one 
+         * entry below the true start (it is immediately incremented
+         * in the loop) */
+         dma_sg--;
+
+        while (nents-- > 0) {
+                unsigned long vaddr;
+                long size;
+
+                DBG_RUN_SG(" %d : %08lx/%05x %08lx/%05x\n", nents,
+                           (unsigned long)sg_dma_address(startsg), cnt,
+                           sg_virt_addr(startsg), startsg->length
+                );
+
+
+                /*
+                ** Look for the start of a new DMA stream
+                */
+                
+                if (sg_dma_address(startsg) & PIDE_FLAG) {
+                        u32 pide = sg_dma_address(startsg) & ~PIDE_FLAG;
+
+                        BUG_ON(pdirp && (dma_len != sg_dma_len(dma_sg)));
+
+                        dma_sg++;
+
+                        dma_len = sg_dma_len(startsg);
+                        sg_dma_len(startsg) = 0;
+                        dma_offset = (unsigned long) pide & ~IOVP_MASK;
+                        n_mappings++;
+#if defined(ZX1_SUPPORT)
+                        /* Pluto IOMMU IO Virt Address is not zero based */
+                        sg_dma_address(dma_sg) = pide | ioc->ibase;
+#else
+                        /* SBA, ccio, and dino are zero based.
+                         * Trying to save a few CPU cycles for most users.
+                         */
+                        sg_dma_address(dma_sg) = pide;
+#endif
+                        pdirp = &(ioc->pdir_base[pide >> IOVP_SHIFT]);
+                        prefetchw(pdirp);
+                }
+                
+                BUG_ON(pdirp == NULL);
+                
+                vaddr = sg_virt_addr(startsg);
+                sg_dma_len(dma_sg) += startsg->length;
+                size = startsg->length + dma_offset;
+                dma_offset = 0;
+#ifdef IOMMU_MAP_STATS
+                ioc->msg_pages += startsg->length >> IOVP_SHIFT;
+#endif
+                do {
+                        iommu_io_pdir_entry(pdirp, KERNEL_SPACE, 
+                                            vaddr, hint);
+                        vaddr += IOVP_SIZE;
+                        size -= IOVP_SIZE;
+                        pdirp++;
+                } while(unlikely(size > 0));
+                startsg++;
+        }
+        return(n_mappings);
+}
+
+
+/*
+** First pass is to walk the SG list and determine where the breaks are
+** in the DMA stream. Allocates PDIR entries but does not fill them.
+** Returns the number of DMA chunks.
+**
+** Doing the fill separate from the coalescing/allocation keeps the
+** code simpler. Future enhancement could make one pass through
+** the sglist do both.
+*/
+
+static inline unsigned int
+iommu_coalesce_chunks(struct ioc *ioc, struct scatterlist *startsg, int nents,
+                      int (*iommu_alloc_range)(struct ioc *, size_t))
+{
+        struct scatterlist *contig_sg;     /* contig chunk head */
+        unsigned long dma_offset, dma_len; /* start/len of DMA stream */
+        unsigned int n_mappings = 0;
+
+        while (nents > 0) {
+
+                /*
+                ** Prepare for first/next DMA stream
+                */
+                contig_sg = startsg;
+                dma_len = startsg->length;
+                dma_offset = sg_virt_addr(startsg) & ~IOVP_MASK;
+
+                /* PARANOID: clear entries */
+                sg_dma_address(startsg) = 0;
+                sg_dma_len(startsg) = 0;
+
+                /*
+                ** This loop terminates one iteration "early" since
+                ** it's always looking one "ahead".
+                */
+                while(--nents > 0) {
+                        unsigned long prevstartsg_end, startsg_end;
+
+                        prevstartsg_end = sg_virt_addr(startsg) +
+                                startsg->length;
+
+                        startsg++;
+                        startsg_end = sg_virt_addr(startsg) + 
+                                startsg->length;
+
+                        /* PARANOID: clear entries */
+                        sg_dma_address(startsg) = 0;
+                        sg_dma_len(startsg) = 0;
+
+                        /*
+                        ** First make sure current dma stream won't
+                        ** exceed DMA_CHUNK_SIZE if we coalesce the
+                        ** next entry.
+                        */   
+                        if(unlikely(ROUNDUP(dma_len + dma_offset + startsg->length,
+                                            IOVP_SIZE) > DMA_CHUNK_SIZE))
+                                break;
+
+                        /*
+                        ** Next see if we can append the next chunk (i.e.
+                        ** it must end on one page and begin on another
+                        */
+                        if (unlikely(((prevstartsg_end | sg_virt_addr(startsg)) & ~PAGE_MASK) != 0))
+                                break;
+                        
+                        dma_len += startsg->length;
+                }
+
+                /*
+                ** End of DMA Stream
+                ** Terminate last VCONTIG block.
+                ** Allocate space for DMA stream.
+                */
+                sg_dma_len(contig_sg) = dma_len;
+                dma_len = ROUNDUP(dma_len + dma_offset, IOVP_SIZE);
+                sg_dma_address(contig_sg) =
+                        PIDE_FLAG 
+                        | (iommu_alloc_range(ioc, dma_len) << IOVP_SHIFT)
+                        | dma_offset;
+                n_mappings++;
+        }
+
+        return n_mappings;
+}
+