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Diffstat (limited to 'arch/frv/mm/dma-alloc.c')
| -rw-r--r-- | arch/frv/mm/dma-alloc.c | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/arch/frv/mm/dma-alloc.c b/arch/frv/mm/dma-alloc.c new file mode 100644 index 00000000..7a73aaea --- /dev/null +++ b/arch/frv/mm/dma-alloc.c @@ -0,0 +1,183 @@ +/* dma-alloc.c: consistent DMA memory allocation + * + * Derived from arch/ppc/mm/cachemap.c + * + * PowerPC version derived from arch/arm/mm/consistent.c + * Copyright (C) 2001 Dan Malek (dmalek@jlc.net) + * + * linux/arch/arm/mm/consistent.c + * + * Copyright (C) 2000 Russell King + * + * Consistent memory allocators. Used for DMA devices that want to + * share uncached memory with the processor core. The function return + * is the virtual address and 'dma_handle' is the physical address. + * Mostly stolen from the ARM port, with some changes for PowerPC. + * -- Dan + * Modified for 36-bit support. -Matt + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/module.h> +#include <linux/signal.h> +#include <linux/sched.h> +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/string.h> +#include <linux/types.h> +#include <linux/ptrace.h> +#include <linux/mman.h> +#include <linux/mm.h> +#include <linux/swap.h> +#include <linux/stddef.h> +#include <linux/vmalloc.h> +#include <linux/init.h> +#include <linux/pci.h> +#include <linux/hardirq.h> +#include <linux/gfp.h> + +#include <asm/pgalloc.h> +#include <asm/io.h> +#include <asm/mmu_context.h> +#include <asm/pgtable.h> +#include <asm/mmu.h> +#include <asm/uaccess.h> +#include <asm/smp.h> + +static int map_page(unsigned long va, unsigned long pa, pgprot_t prot) +{ + pgd_t *pge; + pud_t *pue; + pmd_t *pme; + pte_t *pte; + int err = -ENOMEM; + + /* Use upper 10 bits of VA to index the first level map */ + pge = pgd_offset_k(va); + pue = pud_offset(pge, va); + pme = pmd_offset(pue, va); + + /* Use middle 10 bits of VA to index the second-level map */ + pte = pte_alloc_kernel(pme, va); + if (pte != 0) { + err = 0; + set_pte(pte, mk_pte_phys(pa & PAGE_MASK, prot)); + } + + return err; +} + +/* + * This function will allocate the requested contiguous pages and + * map them into the kernel's vmalloc() space. This is done so we + * get unique mapping for these pages, outside of the kernel's 1:1 + * virtual:physical mapping. This is necessary so we can cover large + * portions of the kernel with single large page TLB entries, and + * still get unique uncached pages for consistent DMA. + */ +void *consistent_alloc(gfp_t gfp, size_t size, dma_addr_t *dma_handle) +{ + struct vm_struct *area; + unsigned long page, va, pa; + void *ret; + int order, err, i; + + if (in_interrupt()) + BUG(); + + /* only allocate page size areas */ + size = PAGE_ALIGN(size); + order = get_order(size); + + page = __get_free_pages(gfp, order); + if (!page) { + BUG(); + return NULL; + } + + /* allocate some common virtual space to map the new pages */ + area = get_vm_area(size, VM_ALLOC); + if (area == 0) { + free_pages(page, order); + return NULL; + } + va = VMALLOC_VMADDR(area->addr); + ret = (void *) va; + + /* this gives us the real physical address of the first page */ + *dma_handle = pa = virt_to_bus((void *) page); + + /* set refcount=1 on all pages in an order>0 allocation so that vfree() will actually free + * all pages that were allocated. + */ + if (order > 0) { + struct page *rpage = virt_to_page(page); + split_page(rpage, order); + } + + err = 0; + for (i = 0; i < size && err == 0; i += PAGE_SIZE) + err = map_page(va + i, pa + i, PAGE_KERNEL_NOCACHE); + + if (err) { + vfree((void *) va); + return NULL; + } + + /* we need to ensure that there are no cachelines in use, or worse dirty in this area + * - can't do until after virtual address mappings are created + */ + frv_cache_invalidate(va, va + size); + + return ret; +} + +/* + * free page(s) as defined by the above mapping. + */ +void consistent_free(void *vaddr) +{ + if (in_interrupt()) + BUG(); + vfree(vaddr); +} + +/* + * make an area consistent. + */ +void consistent_sync(void *vaddr, size_t size, int direction) +{ + unsigned long start = (unsigned long) vaddr; + unsigned long end = start + size; + + switch (direction) { + case PCI_DMA_NONE: + BUG(); + case PCI_DMA_FROMDEVICE: /* invalidate only */ + frv_cache_invalidate(start, end); + break; + case PCI_DMA_TODEVICE: /* writeback only */ + frv_dcache_writeback(start, end); + break; + case PCI_DMA_BIDIRECTIONAL: /* writeback and invalidate */ + frv_dcache_writeback(start, end); + break; + } +} + +/* + * consistent_sync_page make a page are consistent. identical + * to consistent_sync, but takes a struct page instead of a virtual address + */ + +void consistent_sync_page(struct page *page, unsigned long offset, + size_t size, int direction) +{ + void *start; + + start = page_address(page) + offset; + consistent_sync(start, size, direction); +} |