summaryrefslogtreecommitdiff
path: root/arch/xtensa/kernel/pci-dma.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/xtensa/kernel/pci-dma.c')
-rw-r--r--arch/xtensa/kernel/pci-dma.c98
1 files changed, 98 insertions, 0 deletions
diff --git a/arch/xtensa/kernel/pci-dma.c b/arch/xtensa/kernel/pci-dma.c
new file mode 100644
index 000000000..e8b76b8e4
--- /dev/null
+++ b/arch/xtensa/kernel/pci-dma.c
@@ -0,0 +1,98 @@
+/*
+ * arch/xtensa/kernel/pci-dma.c
+ *
+ * DMA coherent memory allocation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * Copyright (C) 2002 - 2005 Tensilica Inc.
+ *
+ * Based on version for i386.
+ *
+ * Chris Zankel <chris@zankel.net>
+ * Joe Taylor <joe@tensilica.com, joetylr@yahoo.com>
+ */
+
+#include <linux/types.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/pci.h>
+#include <linux/gfp.h>
+#include <linux/module.h>
+#include <asm/io.h>
+#include <asm/cacheflush.h>
+
+/*
+ * Note: We assume that the full memory space is always mapped to 'kseg'
+ * Otherwise we have to use page attributes (not implemented).
+ */
+
+void *
+dma_alloc_coherent(struct device *dev,size_t size,dma_addr_t *handle,gfp_t flag)
+{
+ unsigned long ret;
+ unsigned long uncached = 0;
+
+ /* ignore region speicifiers */
+
+ flag &= ~(__GFP_DMA | __GFP_HIGHMEM);
+
+ if (dev == NULL || (dev->coherent_dma_mask < 0xffffffff))
+ flag |= GFP_DMA;
+ ret = (unsigned long)__get_free_pages(flag, get_order(size));
+
+ if (ret == 0)
+ return NULL;
+
+ /* We currently don't support coherent memory outside KSEG */
+
+ BUG_ON(ret < XCHAL_KSEG_CACHED_VADDR ||
+ ret > XCHAL_KSEG_CACHED_VADDR + XCHAL_KSEG_SIZE - 1);
+
+
+ if (ret != 0) {
+ memset((void*) ret, 0, size);
+ uncached = ret+XCHAL_KSEG_BYPASS_VADDR-XCHAL_KSEG_CACHED_VADDR;
+ *handle = virt_to_bus((void*)ret);
+ __flush_invalidate_dcache_range(ret, size);
+ }
+
+ return (void*)uncached;
+}
+EXPORT_SYMBOL(dma_alloc_coherent);
+
+void dma_free_coherent(struct device *hwdev, size_t size,
+ void *vaddr, dma_addr_t dma_handle)
+{
+ unsigned long addr = (unsigned long)vaddr +
+ XCHAL_KSEG_CACHED_VADDR - XCHAL_KSEG_BYPASS_VADDR;
+
+ BUG_ON(addr < XCHAL_KSEG_CACHED_VADDR ||
+ addr > XCHAL_KSEG_CACHED_VADDR + XCHAL_KSEG_SIZE - 1);
+
+ free_pages(addr, get_order(size));
+}
+EXPORT_SYMBOL(dma_free_coherent);
+
+
+void consistent_sync(void *vaddr, size_t size, int direction)
+{
+ switch (direction) {
+ case PCI_DMA_NONE:
+ BUG();
+ case PCI_DMA_FROMDEVICE: /* invalidate only */
+ __invalidate_dcache_range((unsigned long)vaddr,
+ (unsigned long)size);
+ break;
+
+ case PCI_DMA_TODEVICE: /* writeback only */
+ case PCI_DMA_BIDIRECTIONAL: /* writeback and invalidate */
+ __flush_invalidate_dcache_range((unsigned long)vaddr,
+ (unsigned long)size);
+ break;
+ }
+}
+EXPORT_SYMBOL(consistent_sync);