diff options
Diffstat (limited to 'drivers/ieee1394/dma.c')
| -rw-r--r-- | drivers/ieee1394/dma.c | 260 |
1 files changed, 260 insertions, 0 deletions
diff --git a/drivers/ieee1394/dma.c b/drivers/ieee1394/dma.c new file mode 100644 index 00000000000..758819d1999 --- /dev/null +++ b/drivers/ieee1394/dma.c @@ -0,0 +1,260 @@ +/* + * DMA region bookkeeping routines + * + * Copyright (C) 2002 Maas Digital LLC + * + * This code is licensed under the GPL. See the file COPYING in the root + * directory of the kernel sources for details. + */ + +#include <linux/module.h> +#include <linux/vmalloc.h> +#include <linux/slab.h> +#include <linux/mm.h> +#include "dma.h" + +/* dma_prog_region */ + +void dma_prog_region_init(struct dma_prog_region *prog) +{ + prog->kvirt = NULL; + prog->dev = NULL; + prog->n_pages = 0; + prog->bus_addr = 0; +} + +int dma_prog_region_alloc(struct dma_prog_region *prog, unsigned long n_bytes, struct pci_dev *dev) +{ + /* round up to page size */ + n_bytes = PAGE_ALIGN(n_bytes); + + prog->n_pages = n_bytes >> PAGE_SHIFT; + + prog->kvirt = pci_alloc_consistent(dev, n_bytes, &prog->bus_addr); + if (!prog->kvirt) { + printk(KERN_ERR "dma_prog_region_alloc: pci_alloc_consistent() failed\n"); + dma_prog_region_free(prog); + return -ENOMEM; + } + + prog->dev = dev; + + return 0; +} + +void dma_prog_region_free(struct dma_prog_region *prog) +{ + if (prog->kvirt) { + pci_free_consistent(prog->dev, prog->n_pages << PAGE_SHIFT, prog->kvirt, prog->bus_addr); + } + + prog->kvirt = NULL; + prog->dev = NULL; + prog->n_pages = 0; + prog->bus_addr = 0; +} + +/* dma_region */ + +void dma_region_init(struct dma_region *dma) +{ + dma->kvirt = NULL; + dma->dev = NULL; + dma->n_pages = 0; + dma->n_dma_pages = 0; + dma->sglist = NULL; +} + +int dma_region_alloc(struct dma_region *dma, unsigned long n_bytes, struct pci_dev *dev, int direction) +{ + unsigned int i; + + /* round up to page size */ + n_bytes = PAGE_ALIGN(n_bytes); + + dma->n_pages = n_bytes >> PAGE_SHIFT; + + dma->kvirt = vmalloc_32(n_bytes); + if (!dma->kvirt) { + printk(KERN_ERR "dma_region_alloc: vmalloc_32() failed\n"); + goto err; + } + + /* Clear the ram out, no junk to the user */ + memset(dma->kvirt, 0, n_bytes); + + /* allocate scatter/gather list */ + dma->sglist = vmalloc(dma->n_pages * sizeof(*dma->sglist)); + if (!dma->sglist) { + printk(KERN_ERR "dma_region_alloc: vmalloc(sglist) failed\n"); + goto err; + } + + /* just to be safe - this will become unnecessary once sglist->address goes away */ + memset(dma->sglist, 0, dma->n_pages * sizeof(*dma->sglist)); + + /* fill scatter/gather list with pages */ + for (i = 0; i < dma->n_pages; i++) { + unsigned long va = (unsigned long) dma->kvirt + (i << PAGE_SHIFT); + + dma->sglist[i].page = vmalloc_to_page((void *)va); + dma->sglist[i].length = PAGE_SIZE; + } + + /* map sglist to the IOMMU */ + dma->n_dma_pages = pci_map_sg(dev, dma->sglist, dma->n_pages, direction); + + if (dma->n_dma_pages == 0) { + printk(KERN_ERR "dma_region_alloc: pci_map_sg() failed\n"); + goto err; + } + + dma->dev = dev; + dma->direction = direction; + + return 0; + +err: + dma_region_free(dma); + return -ENOMEM; +} + +void dma_region_free(struct dma_region *dma) +{ + if (dma->n_dma_pages) { + pci_unmap_sg(dma->dev, dma->sglist, dma->n_pages, dma->direction); + dma->n_dma_pages = 0; + dma->dev = NULL; + } + + vfree(dma->sglist); + dma->sglist = NULL; + + vfree(dma->kvirt); + dma->kvirt = NULL; + dma->n_pages = 0; +} + +/* find the scatterlist index and remaining offset corresponding to a + given offset from the beginning of the buffer */ +static inline int dma_region_find(struct dma_region *dma, unsigned long offset, unsigned long *rem) +{ + int i; + unsigned long off = offset; + + for (i = 0; i < dma->n_dma_pages; i++) { + if (off < sg_dma_len(&dma->sglist[i])) { + *rem = off; + break; + } + + off -= sg_dma_len(&dma->sglist[i]); + } + + BUG_ON(i >= dma->n_dma_pages); + + return i; +} + +dma_addr_t dma_region_offset_to_bus(struct dma_region *dma, unsigned long offset) +{ + unsigned long rem; + + struct scatterlist *sg = &dma->sglist[dma_region_find(dma, offset, &rem)]; + return sg_dma_address(sg) + rem; +} + +void dma_region_sync_for_cpu(struct dma_region *dma, unsigned long offset, unsigned long len) +{ + int first, last; + unsigned long rem; + + if (!len) + len = 1; + + first = dma_region_find(dma, offset, &rem); + last = dma_region_find(dma, offset + len - 1, &rem); + + pci_dma_sync_sg_for_cpu(dma->dev, &dma->sglist[first], last - first + 1, dma->direction); +} + +void dma_region_sync_for_device(struct dma_region *dma, unsigned long offset, unsigned long len) +{ + int first, last; + unsigned long rem; + + if (!len) + len = 1; + + first = dma_region_find(dma, offset, &rem); + last = dma_region_find(dma, offset + len - 1, &rem); + + pci_dma_sync_sg_for_device(dma->dev, &dma->sglist[first], last - first + 1, dma->direction); +} + +#ifdef CONFIG_MMU + +/* nopage() handler for mmap access */ + +static struct page* +dma_region_pagefault(struct vm_area_struct *area, unsigned long address, int *type) +{ + unsigned long offset; + unsigned long kernel_virt_addr; + struct page *ret = NOPAGE_SIGBUS; + + struct dma_region *dma = (struct dma_region*) area->vm_private_data; + + if (!dma->kvirt) + goto out; + + if ( (address < (unsigned long) area->vm_start) || + (address > (unsigned long) area->vm_start + (dma->n_pages << PAGE_SHIFT)) ) + goto out; + + if (type) + *type = VM_FAULT_MINOR; + offset = address - area->vm_start; + kernel_virt_addr = (unsigned long) dma->kvirt + offset; + ret = vmalloc_to_page((void*) kernel_virt_addr); + get_page(ret); +out: + return ret; +} + +static struct vm_operations_struct dma_region_vm_ops = { + .nopage = dma_region_pagefault, +}; + +int dma_region_mmap(struct dma_region *dma, struct file *file, struct vm_area_struct *vma) +{ + unsigned long size; + + if (!dma->kvirt) + return -EINVAL; + + /* must be page-aligned */ + if (vma->vm_pgoff != 0) + return -EINVAL; + + /* check the length */ + size = vma->vm_end - vma->vm_start; + if (size > (dma->n_pages << PAGE_SHIFT)) + return -EINVAL; + + vma->vm_ops = &dma_region_vm_ops; + vma->vm_private_data = dma; + vma->vm_file = file; + vma->vm_flags |= VM_RESERVED; + + return 0; +} + +#else /* CONFIG_MMU */ + +int dma_region_mmap(struct dma_region *dma, struct file *file, struct vm_area_struct *vma) +{ + return -EINVAL; +} + +#endif /* CONFIG_MMU */ |