iommu sg merging: sparc64: make iommu respect the segment size limits

[h-e-n] / arch / sparc64 / kernel / iommu_common.c

diff --git a/arch/sparc64/kernel/iommu_common.c b/arch/sparc64/kernel/iommu_common.c
index efd5dff..72a4acf 100644 (file)
--- a/arch/sparc64/kernel/iommu_common.c
+++ b/arch/sparc64/kernel/iommu_common.c
@@ -4,6 +4,7 @@
  * Copyright (C) 1999 David S. Miller (davem@redhat.com)
  */
 
+#include <linux/dma-mapping.h>
 #include "iommu_common.h"
 
 /* You are _strongly_ advised to enable the following debugging code
@@ -201,21 +202,24 @@ void verify_sglist(struct scatterlist *sglist, int nents, iopte_t *iopte, int np
 }
 #endif
 
-unsigned long prepare_sg(struct scatterlist *sg, int nents)
+unsigned long prepare_sg(struct device *dev, struct scatterlist *sg, int nents)
 {
        struct scatterlist *dma_sg = sg;
        unsigned long prev;
        u32 dent_addr, dent_len;
+       unsigned int max_seg_size;
 
        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));
+       max_seg_size = dma_get_max_seg_size(dev);
        while (--nents) {
                unsigned long addr;
 
                sg = sg_next(sg);
                addr = (unsigned long) sg_virt(sg);
-               if (! VCONTIG(prev, addr)) {
+               if (! VCONTIG(prev, addr) ||
+                       dent_len + sg->length > max_seg_size) {
                        dma_sg->dma_address = dent_addr;
                        dma_sg->dma_length = dent_len;
                        dma_sg = sg_next(dma_sg);