1 files changed, 17 insertions, 0 deletions

diff --git a/arch/mn10300/mm/dma-alloc.c b/arch/mn10300/mm/dma-alloc.c
index f3649d8f50e3..ee82d624b3c6 100644
--- a/arch/mn10300/mm/dma-alloc.c
+++ b/arch/mn10300/mm/dma-alloc.c
@@ -16,12 +16,24 @@
 #include <linux/pci.h>
 #include <asm/io.h>
 
+static unsigned long pci_sram_allocated = 0xbc000000;
+
 void *dma_alloc_coherent(struct device *dev, size_t size,
                          dma_addr_t *dma_handle, int gfp)
 {
         unsigned long addr;
         void *ret;
 
+        printk("dma_alloc_coherent(%s,%zu,,%x)\n", dev_name(dev), size, gfp);
+
+        if (0xbe000000 - pci_sram_allocated >= size) {
+                size = (size + 255) & ~255;
+                addr = pci_sram_allocated;
+                pci_sram_allocated += size;
+                ret = (void *) addr;
+                goto done;
+        }
+
         /* ignore region specifiers */
         gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);
 
@@ -41,7 +53,9 @@ void *dma_alloc_coherent(struct device *dev, size_t size,
         /* write back and evict all cache lines covering this region */
         mn10300_dcache_flush_inv_range2(virt_to_phys((void *) addr), PAGE_SIZE);
 
+done:
         *dma_handle = virt_to_bus((void *) addr);
+        printk("dma_alloc_coherent() = %p [%x]\n", ret, *dma_handle);
         return ret;
 }
 EXPORT_SYMBOL(dma_alloc_coherent);
@@ -51,6 +65,9 @@ void dma_free_coherent(struct device *dev, size_t size, void *vaddr,
 {
         unsigned long addr = (unsigned long) vaddr & ~0x20000000;
 
+        if (addr >= 0x9c000000)
+                return;
+
         free_pages(addr, get_order(size));
 }
 EXPORT_SYMBOL(dma_free_coherent);