diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/frv/mb93090-mb00/pci-dma-nommu.c |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/frv/mb93090-mb00/pci-dma-nommu.c')
-rw-r--r-- | arch/frv/mb93090-mb00/pci-dma-nommu.c | 152 |
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; +} |