2005-04-16 16:20:36 -06:00
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/* dma-alloc.c: consistent DMA memory allocation
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*
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* Derived from arch/ppc/mm/cachemap.c
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*
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* PowerPC version derived from arch/arm/mm/consistent.c
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* Copyright (C) 2001 Dan Malek (dmalek@jlc.net)
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*
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* linux/arch/arm/mm/consistent.c
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*
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* Copyright (C) 2000 Russell King
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*
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* Consistent memory allocators. Used for DMA devices that want to
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* share uncached memory with the processor core. The function return
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* is the virtual address and 'dma_handle' is the physical address.
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* Mostly stolen from the ARM port, with some changes for PowerPC.
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* -- Dan
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* Modified for 36-bit support. -Matt
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/config.h>
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#include <linux/module.h>
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#include <linux/signal.h>
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#include <linux/sched.h>
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/string.h>
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#include <linux/types.h>
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#include <linux/ptrace.h>
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#include <linux/mman.h>
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#include <linux/mm.h>
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#include <linux/swap.h>
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#include <linux/stddef.h>
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#include <linux/vmalloc.h>
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#include <linux/init.h>
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#include <linux/pci.h>
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#include <asm/pgalloc.h>
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#include <asm/io.h>
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#include <asm/hardirq.h>
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#include <asm/mmu_context.h>
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#include <asm/pgtable.h>
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#include <asm/mmu.h>
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#include <asm/uaccess.h>
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#include <asm/smp.h>
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static int map_page(unsigned long va, unsigned long pa, pgprot_t prot)
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{
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pgd_t *pge;
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pud_t *pue;
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pmd_t *pme;
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pte_t *pte;
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int err = -ENOMEM;
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spin_lock(&init_mm.page_table_lock);
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/* Use upper 10 bits of VA to index the first level map */
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pge = pgd_offset_k(va);
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pue = pud_offset(pge, va);
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pme = pmd_offset(pue, va);
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/* Use middle 10 bits of VA to index the second-level map */
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pte = pte_alloc_kernel(&init_mm, pme, va);
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if (pte != 0) {
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err = 0;
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set_pte(pte, mk_pte_phys(pa & PAGE_MASK, prot));
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}
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spin_unlock(&init_mm.page_table_lock);
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return err;
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}
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/*
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* This function will allocate the requested contiguous pages and
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* map them into the kernel's vmalloc() space. This is done so we
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* get unique mapping for these pages, outside of the kernel's 1:1
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* virtual:physical mapping. This is necessary so we can cover large
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* portions of the kernel with single large page TLB entries, and
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* still get unique uncached pages for consistent DMA.
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*/
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2005-10-21 01:21:18 -06:00
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void *consistent_alloc(gfp_t gfp, size_t size, dma_addr_t *dma_handle)
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2005-04-16 16:20:36 -06:00
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{
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struct vm_struct *area;
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unsigned long page, va, pa;
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void *ret;
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int order, err, i;
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if (in_interrupt())
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BUG();
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/* only allocate page size areas */
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size = PAGE_ALIGN(size);
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order = get_order(size);
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page = __get_free_pages(gfp, order);
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if (!page) {
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BUG();
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return NULL;
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}
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/* allocate some common virtual space to map the new pages */
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area = get_vm_area(size, VM_ALLOC);
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if (area == 0) {
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free_pages(page, order);
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return NULL;
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}
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va = VMALLOC_VMADDR(area->addr);
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ret = (void *) va;
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/* this gives us the real physical address of the first page */
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*dma_handle = pa = virt_to_bus((void *) page);
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/* set refcount=1 on all pages in an order>0 allocation so that vfree() will actually free
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* all pages that were allocated.
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*/
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if (order > 0) {
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struct page *rpage = virt_to_page(page);
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for (i = 1; i < (1 << order); i++)
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set_page_count(rpage + i, 1);
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}
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err = 0;
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for (i = 0; i < size && err == 0; i += PAGE_SIZE)
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err = map_page(va + i, pa + i, PAGE_KERNEL_NOCACHE);
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if (err) {
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vfree((void *) va);
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return NULL;
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}
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/* we need to ensure that there are no cachelines in use, or worse dirty in this area
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* - can't do until after virtual address mappings are created
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*/
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frv_cache_invalidate(va, va + size);
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return ret;
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}
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/*
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* free page(s) as defined by the above mapping.
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*/
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void consistent_free(void *vaddr)
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{
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if (in_interrupt())
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BUG();
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vfree(vaddr);
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}
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/*
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* make an area consistent.
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*/
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void consistent_sync(void *vaddr, size_t size, int direction)
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{
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unsigned long start = (unsigned long) vaddr;
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unsigned long end = start + size;
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switch (direction) {
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case PCI_DMA_NONE:
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BUG();
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case PCI_DMA_FROMDEVICE: /* invalidate only */
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frv_cache_invalidate(start, end);
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break;
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case PCI_DMA_TODEVICE: /* writeback only */
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frv_dcache_writeback(start, end);
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break;
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case PCI_DMA_BIDIRECTIONAL: /* writeback and invalidate */
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frv_dcache_writeback(start, end);
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break;
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}
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}
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/*
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* consistent_sync_page make a page are consistent. identical
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* to consistent_sync, but takes a struct page instead of a virtual address
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*/
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void consistent_sync_page(struct page *page, unsigned long offset,
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size_t size, int direction)
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{
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void *start;
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start = page_address(page) + offset;
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consistent_sync(start, size, direction);
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}
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