153 lines
4.0 KiB
C
153 lines
4.0 KiB
C
/* 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, gfp_t 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;
|
|
}
|