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Diffstat (limited to 'arch/frv/mb93090-mb00/pci-dma-nommu.c')
-rw-r--r--arch/frv/mb93090-mb00/pci-dma-nommu.c152
1 files changed, 152 insertions, 0 deletions
diff --git a/arch/frv/mb93090-mb00/pci-dma-nommu.c b/arch/frv/mb93090-mb00/pci-dma-nommu.c
new file mode 100644
index 000000000000..819895cf0b9e
--- /dev/null
+++ b/arch/frv/mb93090-mb00/pci-dma-nommu.c
@@ -0,0 +1,152 @@
+/* pci-dma-nommu.c: Dynamic DMA mapping support for the FRV
+ *
+ * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
+ * Written by David Woodhouse (dwmw2@redhat.com)
+ *
+ * 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.
+ */
+
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/dma-mapping.h>
+#include <linux/list.h>
+#include <linux/pci.h>
+#include <asm/io.h>
+
+#if 1
+#define DMA_SRAM_START dma_coherent_mem_start
+#define DMA_SRAM_END dma_coherent_mem_end
+#else // Use video RAM on Matrox
+#define DMA_SRAM_START 0xe8900000
+#define DMA_SRAM_END 0xe8a00000
+#endif
+
+struct dma_alloc_record {
+ struct list_head list;
+ unsigned long ofs;
+ unsigned long len;
+};
+
+static DEFINE_SPINLOCK(dma_alloc_lock);
+static LIST_HEAD(dma_alloc_list);
+
+void *dma_alloc_coherent(struct device *hwdev, size_t size, dma_addr_t *dma_handle, int gfp)
+{
+ struct dma_alloc_record *new;
+ struct list_head *this = &dma_alloc_list;
+ unsigned long flags;
+ unsigned long start = DMA_SRAM_START;
+ unsigned long end;
+
+ if (!DMA_SRAM_START) {
+ printk("%s called without any DMA area reserved!\n", __func__);
+ return NULL;
+ }
+
+ new = kmalloc(sizeof (*new), GFP_ATOMIC);
+ if (!new)
+ return NULL;
+
+ /* Round up to a reasonable alignment */
+ new->len = (size + 31) & ~31;
+
+ spin_lock_irqsave(&dma_alloc_lock, flags);
+
+ list_for_each (this, &dma_alloc_list) {
+ struct dma_alloc_record *this_r = list_entry(this, struct dma_alloc_record, list);
+ end = this_r->ofs;
+
+ if (end - start >= size)
+ goto gotone;
+
+ start = this_r->ofs + this_r->len;
+ }
+ /* Reached end of list. */
+ end = DMA_SRAM_END;
+ this = &dma_alloc_list;
+
+ if (end - start >= size) {
+ gotone:
+ new->ofs = start;
+ list_add_tail(&new->list, this);
+ spin_unlock_irqrestore(&dma_alloc_lock, flags);
+
+ *dma_handle = start;
+ return (void *)start;
+ }
+
+ kfree(new);
+ spin_unlock_irqrestore(&dma_alloc_lock, flags);
+ return NULL;
+}
+
+void dma_free_coherent(struct device *hwdev, size_t size, void *vaddr, dma_addr_t dma_handle)
+{
+ struct dma_alloc_record *rec;
+ unsigned long flags;
+
+ spin_lock_irqsave(&dma_alloc_lock, flags);
+
+ list_for_each_entry(rec, &dma_alloc_list, list) {
+ if (rec->ofs == dma_handle) {
+ list_del(&rec->list);
+ kfree(rec);
+ spin_unlock_irqrestore(&dma_alloc_lock, flags);
+ return;
+ }
+ }
+ spin_unlock_irqrestore(&dma_alloc_lock, flags);
+ BUG();
+}
+
+/*
+ * Map a single buffer of the indicated size for DMA in streaming mode.
+ * The 32-bit bus address to use is returned.
+ *
+ * Once the device is given the dma address, the device owns this memory
+ * until either pci_unmap_single or pci_dma_sync_single is performed.
+ */
+dma_addr_t dma_map_single(struct device *dev, void *ptr, size_t size,
+ enum dma_data_direction direction)
+{
+ if (direction == DMA_NONE)
+ BUG();
+
+ frv_cache_wback_inv((unsigned long) ptr, (unsigned long) ptr + size);
+
+ return virt_to_bus(ptr);
+}
+
+/*
+ * Map a set of buffers described by scatterlist in streaming
+ * mode for DMA. This is the scather-gather version of the
+ * above pci_map_single interface. Here the scatter gather list
+ * elements are each tagged with the appropriate dma address
+ * and length. They are obtained via sg_dma_{address,length}(SG).
+ *
+ * NOTE: An implementation may be able to use a smaller number of
+ * DMA address/length pairs than there are SG table elements.
+ * (for example via virtual mapping capabilities)
+ * The routine returns the number of addr/length pairs actually
+ * used, at most nents.
+ *
+ * Device ownership issues as mentioned above for pci_map_single are
+ * the same here.
+ */
+int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
+ enum dma_data_direction direction)
+{
+ int i;
+
+ for (i=0; i<nents; i++)
+ frv_cache_wback_inv(sg_dma_address(&sg[i]),
+ sg_dma_address(&sg[i]) + sg_dma_len(&sg[i]));
+
+ if (direction == DMA_NONE)
+ BUG();
+
+ return nents;
+}