blob: 766265bfe68162adc33e7a1ee29a77e6924829b8 [file] [log] [blame]
* PowerPC version derived from arch/arm/mm/consistent.c
* Copyright (C) 2001 Dan Malek (
* 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/config.h>
#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/delay.h>
#include <linux/bootmem.h>
#include <linux/highmem.h>
#include <linux/pci.h>
#include <asm/pgalloc.h>
#include <asm/prom.h>
#include <asm/io.h>
#include <asm/hardirq.h>
#include <asm/mmu_context.h>
#include <asm/pgtable.h>
#include <asm/mmu.h>
#include <asm/uaccess.h>
#include <asm/smp.h>
#include <asm/machdep.h>
#include "mmu_decl.h"
extern int map_page(unsigned long va, phys_addr_t pa, int flags);
/* 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(int gfp, size_t size, dma_addr_t *dma_handle)
int order, err, i;
unsigned long page, va, flags;
phys_addr_t pa;
struct vm_struct *area;
void *ret;
if (in_interrupt())
/* Only allocate page size areas.
size = PAGE_ALIGN(size);
order = get_order(size);
page = __get_free_pages(gfp, order);
if (!page) {
return NULL;
* we need to ensure that there are no cachelines in use,
* or worse dirty in this area.
invalidate_dcache_range(page, page + size);
/* 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);
for (i = 1; i < (1 << order); i++)
set_page_count(rpage+i, 1);
err = 0;
for (i = 0; i < size && err == 0; i += PAGE_SIZE)
err = map_page(va+i, pa+i, flags);
if (err) {
vfree((void *)va);
return NULL;
return ret;
* free page(s) as defined by the above mapping.
void consistent_free(void *vaddr)
if (in_interrupt())
* 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_FROMDEVICE: /* invalidate only */
invalidate_dcache_range(start, end);
case PCI_DMA_TODEVICE: /* writeback only */
clean_dcache_range(start, end);
case PCI_DMA_BIDIRECTIONAL: /* writeback and invalidate */
flush_dcache_range(start, end);
* 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);