* Copyright (C) 2001 Dan Malek (dmalek@jlc.net)
*
* 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
- *
- * Reorganized to get rid of the arch-specific consistent_* functions
- * and provide non-coherent implementations for the DMA API. -Matt
- *
- * Added in_interrupt() safe dma_alloc_coherent()/dma_free_coherent()
- * implementation. This is pulled straight from ARM and barely
- * modified. -Matt
*/
-#include <linux/sched.h>
-#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/errno.h>
-#include <linux/string.h>
#include <linux/types.h>
#include <linux/highmem.h>
#include <linux/dma-direct.h>
#include <linux/dma-noncoherent.h>
-#include <linux/export.h>
#include <asm/tlbflush.h>
#include <asm/dma.h>
-#include <mm/mmu_decl.h>
-
-/*
- * This address range defaults to a value that is safe for all
- * platforms which currently set CONFIG_NOT_COHERENT_CACHE. It
- * can be further configured for specific applications under
- * the "Advanced Setup" menu. -Matt
- */
-#define CONSISTENT_BASE (IOREMAP_TOP)
-#define CONSISTENT_END (CONSISTENT_BASE + CONFIG_CONSISTENT_SIZE)
-#define CONSISTENT_OFFSET(x) (((unsigned long)(x) - CONSISTENT_BASE) >> PAGE_SHIFT)
-
-/*
- * This is the page table (2MB) covering uncached, DMA consistent allocations
- */
-static DEFINE_SPINLOCK(consistent_lock);
-
-/*
- * VM region handling support.
- *
- * This should become something generic, handling VM region allocations for
- * vmalloc and similar (ioremap, module space, etc).
- *
- * I envisage vmalloc()'s supporting vm_struct becoming:
- *
- * struct vm_struct {
- * struct vm_region region;
- * unsigned long flags;
- * struct page **pages;
- * unsigned int nr_pages;
- * unsigned long phys_addr;
- * };
- *
- * get_vm_area() would then call vm_region_alloc with an appropriate
- * struct vm_region head (eg):
- *
- * struct vm_region vmalloc_head = {
- * .vm_list = LIST_HEAD_INIT(vmalloc_head.vm_list),
- * .vm_start = VMALLOC_START,
- * .vm_end = VMALLOC_END,
- * };
- *
- * However, vmalloc_head.vm_start is variable (typically, it is dependent on
- * the amount of RAM found at boot time.) I would imagine that get_vm_area()
- * would have to initialise this each time prior to calling vm_region_alloc().
- */
-struct ppc_vm_region {
- struct list_head vm_list;
- unsigned long vm_start;
- unsigned long vm_end;
-};
-
-static struct ppc_vm_region consistent_head = {
- .vm_list = LIST_HEAD_INIT(consistent_head.vm_list),
- .vm_start = CONSISTENT_BASE,
- .vm_end = CONSISTENT_END,
-};
-
-static struct ppc_vm_region *
-ppc_vm_region_alloc(struct ppc_vm_region *head, size_t size, gfp_t gfp)
-{
- unsigned long addr = head->vm_start, end = head->vm_end - size;
- unsigned long flags;
- struct ppc_vm_region *c, *new;
-
- new = kmalloc(sizeof(struct ppc_vm_region), gfp);
- if (!new)
- goto out;
-
- spin_lock_irqsave(&consistent_lock, flags);
-
- list_for_each_entry(c, &head->vm_list, vm_list) {
- if ((addr + size) < addr)
- goto nospc;
- if ((addr + size) <= c->vm_start)
- goto found;
- addr = c->vm_end;
- if (addr > end)
- goto nospc;
- }
-
- found:
- /*
- * Insert this entry _before_ the one we found.
- */
- list_add_tail(&new->vm_list, &c->vm_list);
- new->vm_start = addr;
- new->vm_end = addr + size;
-
- spin_unlock_irqrestore(&consistent_lock, flags);
- return new;
-
- nospc:
- spin_unlock_irqrestore(&consistent_lock, flags);
- kfree(new);
- out:
- return NULL;
-}
-
-static struct ppc_vm_region *ppc_vm_region_find(struct ppc_vm_region *head, unsigned long addr)
-{
- struct ppc_vm_region *c;
-
- list_for_each_entry(c, &head->vm_list, vm_list) {
- if (c->vm_start == addr)
- goto out;
- }
- c = NULL;
- out:
- return c;
-}
-
-/*
- * Allocate DMA-coherent memory space and return both the kernel remapped
- * virtual and bus address for that space.
- */
-void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
- gfp_t gfp, unsigned long attrs)
-{
- struct page *page;
- struct ppc_vm_region *c;
- unsigned long order;
- u64 mask = ISA_DMA_THRESHOLD, limit;
-
- if (dev) {
- mask = dev->coherent_dma_mask;
-
- /*
- * Sanity check the DMA mask - it must be non-zero, and
- * must be able to be satisfied by a DMA allocation.
- */
- if (mask == 0) {
- dev_warn(dev, "coherent DMA mask is unset\n");
- goto no_page;
- }
-
- if ((~mask) & ISA_DMA_THRESHOLD) {
- dev_warn(dev, "coherent DMA mask %#llx is smaller "
- "than system GFP_DMA mask %#llx\n",
- mask, (unsigned long long)ISA_DMA_THRESHOLD);
- goto no_page;
- }
- }
-
-
- size = PAGE_ALIGN(size);
- limit = (mask + 1) & ~mask;
- if ((limit && size >= limit) ||
- size >= (CONSISTENT_END - CONSISTENT_BASE)) {
- printk(KERN_WARNING "coherent allocation too big (requested %#x mask %#Lx)\n",
- size, mask);
- return NULL;
- }
-
- order = get_order(size);
-
- /* Might be useful if we ever have a real legacy DMA zone... */
- if (mask != 0xffffffff)
- gfp |= GFP_DMA;
-
- page = alloc_pages(gfp, order);
- if (!page)
- goto no_page;
-
- /*
- * Invalidate any data that might be lurking in the
- * kernel direct-mapped region for device DMA.
- */
- {
- unsigned long kaddr = (unsigned long)page_address(page);
- memset(page_address(page), 0, size);
- flush_dcache_range(kaddr, kaddr + size);
- }
-
- /*
- * Allocate a virtual address in the consistent mapping region.
- */
- c = ppc_vm_region_alloc(&consistent_head, size,
- gfp & ~(__GFP_DMA | __GFP_HIGHMEM));
- if (c) {
- unsigned long vaddr = c->vm_start;
- struct page *end = page + (1 << order);
-
- split_page(page, order);
-
- /*
- * Set the "dma handle"
- */
- *dma_handle = phys_to_dma(dev, page_to_phys(page));
-
- do {
- SetPageReserved(page);
- map_kernel_page(vaddr, page_to_phys(page),
- pgprot_noncached(PAGE_KERNEL));
- page++;
- vaddr += PAGE_SIZE;
- } while (size -= PAGE_SIZE);
-
- /*
- * Free the otherwise unused pages.
- */
- while (page < end) {
- __free_page(page);
- page++;
- }
-
- return (void *)c->vm_start;
- }
-
- if (page)
- __free_pages(page, order);
- no_page:
- return NULL;
-}
-
-/*
- * free a page as defined by the above mapping.
- */
-void arch_dma_free(struct device *dev, size_t size, void *vaddr,
- dma_addr_t dma_handle, unsigned long attrs)
-{
- struct ppc_vm_region *c;
- unsigned long flags, addr;
-
- size = PAGE_ALIGN(size);
-
- spin_lock_irqsave(&consistent_lock, flags);
-
- c = ppc_vm_region_find(&consistent_head, (unsigned long)vaddr);
- if (!c)
- goto no_area;
-
- if ((c->vm_end - c->vm_start) != size) {
- printk(KERN_ERR "%s: freeing wrong coherent size (%ld != %d)\n",
- __func__, c->vm_end - c->vm_start, size);
- dump_stack();
- size = c->vm_end - c->vm_start;
- }
-
- addr = c->vm_start;
- do {
- pte_t *ptep;
- unsigned long pfn;
-
- ptep = pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(addr),
- addr),
- addr),
- addr);
- if (!pte_none(*ptep) && pte_present(*ptep)) {
- pfn = pte_pfn(*ptep);
- pte_clear(&init_mm, addr, ptep);
- if (pfn_valid(pfn)) {
- struct page *page = pfn_to_page(pfn);
- __free_reserved_page(page);
- }
- }
- addr += PAGE_SIZE;
- } while (size -= PAGE_SIZE);
-
- flush_tlb_kernel_range(c->vm_start, c->vm_end);
-
- list_del(&c->vm_list);
-
- spin_unlock_irqrestore(&consistent_lock, flags);
-
- kfree(c);
- return;
-
- no_area:
- spin_unlock_irqrestore(&consistent_lock, flags);
- printk(KERN_ERR "%s: trying to free invalid coherent area: %p\n",
- __func__, vaddr);
- dump_stack();
-}
-
/*
* make an area consistent.
*/
__dma_sync_page(paddr, size, dir);
}
-/*
- * Return the PFN for a given cpu virtual address returned by arch_dma_alloc.
- */
-long arch_dma_coherent_to_pfn(struct device *dev, void *vaddr,
- dma_addr_t dma_addr)
+void arch_dma_prep_coherent(struct page *page, size_t size)
{
- /* This should always be populated, so we don't test every
- * level. If that fails, we'll have a nice crash which
- * will be as good as a BUG_ON()
- */
- unsigned long cpu_addr = (unsigned long)vaddr;
- pgd_t *pgd = pgd_offset_k(cpu_addr);
- pud_t *pud = pud_offset(pgd, cpu_addr);
- pmd_t *pmd = pmd_offset(pud, cpu_addr);
- pte_t *ptep = pte_offset_kernel(pmd, cpu_addr);
+ unsigned long kaddr = (unsigned long)page_address(page);
- if (pte_none(*ptep) || !pte_present(*ptep))
- return 0;
- return pte_pfn(*ptep);
+ flush_dcache_range(kaddr, kaddr + size);
+}
+
+static int __init atomic_pool_init(void)
+{
+ return dma_atomic_pool_init(GFP_KERNEL, pgprot_noncached(PAGE_KERNEL));
}
+postcore_initcall(atomic_pool_init);
projects / linux.git / commitdiff