File-copy from v4.4.100
This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Please refer to that tree for all history prior to this point.
Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/arch/mn10300/mm/dma-alloc.c b/arch/mn10300/mm/dma-alloc.c
new file mode 100644
index 0000000..e244ebe
--- /dev/null
+++ b/arch/mn10300/mm/dma-alloc.c
@@ -0,0 +1,76 @@
+/* MN10300 Dynamic DMA mapping support
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ * Derived from: arch/i386/kernel/pci-dma.c
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#include <linux/types.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/pci.h>
+#include <linux/gfp.h>
+#include <linux/export.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;
+
+ pr_debug("dma_alloc_coherent(%s,%zu,%x)\n",
+ dev ? 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);
+
+ if (dev == NULL || dev->coherent_dma_mask < 0xffffffff)
+ gfp |= GFP_DMA;
+
+ addr = __get_free_pages(gfp, get_order(size));
+ if (!addr)
+ return NULL;
+
+ /* map the coherent memory through the uncached memory window */
+ ret = (void *) (addr | 0x20000000);
+
+ /* fill the memory with obvious rubbish */
+ memset((void *) addr, 0xfb, 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);
+
+void dma_free_coherent(struct device *dev, size_t size, void *vaddr,
+ dma_addr_t dma_handle)
+{
+ unsigned long addr = (unsigned long) vaddr & ~0x20000000;
+
+ if (addr >= 0x9c000000)
+ return;
+
+ free_pages(addr, get_order(size));
+}
+EXPORT_SYMBOL(dma_free_coherent);