LXR linux/arch/frv/mm/dma-alloc.c

   1/* dma-alloc.c: consistent DMA memory allocation
   2 *
   3 * Derived from arch/ppc/mm/cachemap.c
   4 *
   5 *  PowerPC version derived from arch/arm/mm/consistent.c
   6 *    Copyright (C) 2001 Dan Malek (dmalek@jlc.net)
   7 *
   8 *  linux/arch/arm/mm/consistent.c
   9 *
  10 *  Copyright (C) 2000 Russell King
  11 *
  12 * Consistent memory allocators.  Used for DMA devices that want to
  13 * share uncached memory with the processor core.  The function return
  14 * is the virtual address and 'dma_handle' is the physical address.
  15 * Mostly stolen from the ARM port, with some changes for PowerPC.
  16 *                                              -- Dan
  17 * Modified for 36-bit support.  -Matt
  18 *
  19 * This program is free software; you can redistribute it and/or modify
  20 * it under the terms of the GNU General Public License version 2 as
  21 * published by the Free Software Foundation.
  22 */
  23
  24#include <linux/module.h>
  25#include <linux/signal.h>
  26#include <linux/sched.h>
  27#include <linux/kernel.h>
  28#include <linux/errno.h>
  29#include <linux/string.h>
  30#include <linux/types.h>
  31#include <linux/ptrace.h>
  32#include <linux/mman.h>
  33#include <linux/mm.h>
  34#include <linux/swap.h>
  35#include <linux/stddef.h>
  36#include <linux/vmalloc.h>
  37#include <linux/init.h>
  38#include <linux/pci.h>
  39#include <linux/hardirq.h>
  40#include <linux/gfp.h>
  41
  42#include <asm/pgalloc.h>
  43#include <asm/io.h>
  44#include <asm/mmu_context.h>
  45#include <asm/pgtable.h>
  46#include <asm/mmu.h>
  47#include <asm/uaccess.h>
  48#include <asm/smp.h>
  49
  50static int map_page(unsigned long va, unsigned long pa, pgprot_t prot)
  51{
  52        pgd_t *pge;
  53        pud_t *pue;
  54        pmd_t *pme;
  55        pte_t *pte;
  56        int err = -ENOMEM;
  57
  58        /* Use upper 10 bits of VA to index the first level map */
  59        pge = pgd_offset_k(va);
  60        pue = pud_offset(pge, va);
  61        pme = pmd_offset(pue, va);
  62
  63        /* Use middle 10 bits of VA to index the second-level map */
  64        pte = pte_alloc_kernel(pme, va);
  65        if (pte != 0) {
  66                err = 0;
  67                set_pte(pte, mk_pte_phys(pa & PAGE_MASK, prot));
  68        }
  69
  70        return err;
  71}
  72
  73/*
  74 * This function will allocate the requested contiguous pages and
  75 * map them into the kernel's vmalloc() space.  This is done so we
  76 * get unique mapping for these pages, outside of the kernel's 1:1
  77 * virtual:physical mapping.  This is necessary so we can cover large
  78 * portions of the kernel with single large page TLB entries, and
  79 * still get unique uncached pages for consistent DMA.
  80 */
  81void *consistent_alloc(gfp_t gfp, size_t size, dma_addr_t *dma_handle)
  82{
  83        struct vm_struct *area;
  84        unsigned long page, va, pa;
  85        void *ret;
  86        int order, err, i;
  87
  88        if (in_interrupt())
  89                BUG();
  90
  91        /* only allocate page size areas */
  92        size = PAGE_ALIGN(size);
  93        order = get_order(size);
  94
  95        page = __get_free_pages(gfp, order);
  96        if (!page) {
  97                BUG();
  98                return NULL;
  99        }
 100
 101        /* allocate some common virtual space to map the new pages */
 102        area = get_vm_area(size, VM_ALLOC);
 103        if (area == 0) {
 104                free_pages(page, order);
 105                return NULL;
 106        }
 107        va = VMALLOC_VMADDR(area->addr);
 108        ret = (void *) va;
 109
 110        /* this gives us the real physical address of the first page */
 111        *dma_handle = pa = virt_to_bus((void *) page);
 112
 113        /* set refcount=1 on all pages in an order>0 allocation so that vfree() will actually free
 114         * all pages that were allocated.
 115         */
 116        if (order > 0) {
 117                struct page *rpage = virt_to_page(page);
 118                split_page(rpage, order);
 119        }
 120
 121        err = 0;
 122        for (i = 0; i < size && err == 0; i += PAGE_SIZE)
 123                err = map_page(va + i, pa + i, PAGE_KERNEL_NOCACHE);
 124
 125        if (err) {
 126                vfree((void *) va);
 127                return NULL;
 128        }
 129
 130        /* we need to ensure that there are no cachelines in use, or worse dirty in this area
 131         * - can't do until after virtual address mappings are created
 132         */
 133        frv_cache_invalidate(va, va + size);
 134
 135        return ret;
 136}
 137
 138/*
 139 * free page(s) as defined by the above mapping.
 140 */
 141void consistent_free(void *vaddr)
 142{
 143        if (in_interrupt())
 144                BUG();
 145        vfree(vaddr);
 146}
 147
 148/*
 149 * make an area consistent.
 150 */
 151void consistent_sync(void *vaddr, size_t size, int direction)
 152{
 153        unsigned long start = (unsigned long) vaddr;
 154        unsigned long end   = start + size;
 155
 156        switch (direction) {
 157        case PCI_DMA_NONE:
 158                BUG();
 159        case PCI_DMA_FROMDEVICE:        /* invalidate only */
 160                frv_cache_invalidate(start, end);
 161                break;
 162        case PCI_DMA_TODEVICE:          /* writeback only */
 163                frv_dcache_writeback(start, end);
 164                break;
 165        case PCI_DMA_BIDIRECTIONAL:     /* writeback and invalidate */
 166                frv_dcache_writeback(start, end);
 167                break;
 168        }
 169}
 170
 171/*
 172 * consistent_sync_page make a page are consistent. identical
 173 * to consistent_sync, but takes a struct page instead of a virtual address
 174 */
 175
 176void consistent_sync_page(struct page *page, unsigned long offset,
 177                          size_t size, int direction)
 178{
 179        void *start;
 180
 181        start = page_address(page) + offset;
 182        consistent_sync(start, size, direction);
 183}
 184