#include <linux/types.h>
#include <linux/highmem.h>
#include <linux/dma-mapping.h>
+#include <linux/vmalloc.h>
#include <asm/tlbflush.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 (CONFIG_CONSISTENT_START)
-#define CONSISTENT_END (CONFIG_CONSISTENT_START + 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 pte_t *consistent_pte;
-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.
__dma_alloc_coherent(size_t size, dma_addr_t *handle, gfp_t gfp)
{
struct page *page;
- struct ppc_vm_region *c;
unsigned long order;
+ int i;
+ unsigned int nr_pages = PAGE_ALIGN(size)>>PAGE_SHIFT;
+ unsigned int array_size = nr_pages * sizeof(struct page *);
+ struct page **pages;
+ struct page *end;
u64 mask = 0x00ffffff, limit; /* ISA default */
+ struct vm_struct *area;
- if (!consistent_pte) {
- printk(KERN_ERR "%s: not initialised\n", __func__);
- dump_stack();
- return NULL;
- }
-
+ BUG_ON(!mem_init_done);
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);
+ if (limit && size >= limit) {
+ printk(KERN_WARNING "coherent allocation too big (requested "
+ "%#x mask %#Lx)\n", size, mask);
return NULL;
}
if (!page)
goto no_page;
+ end = page + (1 << order);
+
/*
* Invalidate any data that might be lurking in the
* kernel direct-mapped region for device DMA.
flush_dcache_range(kaddr, kaddr + size);
}
+ split_page(page, order);
+
/*
- * Allocate a virtual address in the consistent mapping region.
+ * Set the "dma handle"
*/
- c = ppc_vm_region_alloc(&consistent_head, size,
- gfp & ~(__GFP_DMA | __GFP_HIGHMEM));
- if (c) {
- unsigned long vaddr = c->vm_start;
- pte_t *pte = consistent_pte + CONSISTENT_OFFSET(vaddr);
- struct page *end = page + (1 << order);
-
- split_page(page, order);
-
- /*
- * Set the "dma handle"
- */
- *handle = page_to_phys(page);
+ *handle = page_to_phys(page);
+
+ area = get_vm_area_caller(size, VM_IOREMAP,
+ __builtin_return_address(1));
+ if (!area)
+ goto out_free_pages;
+
+ if (array_size > PAGE_SIZE) {
+ pages = vmalloc(array_size);
+ area->flags |= VM_VPAGES;
+ } else {
+ pages = kmalloc(array_size, GFP_KERNEL);
+ }
+ if (!pages)
+ goto out_free_area;
- do {
- BUG_ON(!pte_none(*pte));
+ area->pages = pages;
+ area->nr_pages = nr_pages;
- SetPageReserved(page);
- set_pte_at(&init_mm, vaddr,
- pte, mk_pte(page, pgprot_noncached(PAGE_KERNEL)));
- page++;
- pte++;
- vaddr += PAGE_SIZE;
- } while (size -= PAGE_SIZE);
+ for (i = 0; i < nr_pages; i++)
+ pages[i] = page + i;
- /*
- * Free the otherwise unused pages.
- */
- while (page < end) {
- __free_page(page);
- page++;
- }
+ if (map_vm_area(area, pgprot_noncached(PAGE_KERNEL), &pages))
+ goto out_unmap;
- return (void *)c->vm_start;
+ /*
+ * Free the otherwise unused pages.
+ */
+ page += nr_pages;
+ while (page < end) {
+ __free_page(page);
+ page++;
}
+ return area->addr;
+out_unmap:
+ vunmap(area->addr);
+ if (array_size > PAGE_SIZE)
+ vfree(pages);
+ else
+ kfree(pages);
+ goto out_free_pages;
+out_free_area:
+ free_vm_area(area);
+out_free_pages:
if (page)
__free_pages(page, order);
- no_page:
+no_page:
return NULL;
}
EXPORT_SYMBOL(__dma_alloc_coherent);
*/
void __dma_free_coherent(size_t size, void *vaddr)
{
- struct ppc_vm_region *c;
- unsigned long flags, addr;
- pte_t *ptep;
-
- 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;
- }
-
- ptep = consistent_pte + CONSISTENT_OFFSET(c->vm_start);
- addr = c->vm_start;
- do {
- pte_t pte = ptep_get_and_clear(&init_mm, addr, ptep);
- unsigned long pfn;
-
- ptep++;
- addr += PAGE_SIZE;
+ vfree(vaddr);
- if (!pte_none(pte) && pte_present(pte)) {
- pfn = pte_pfn(pte);
-
- if (pfn_valid(pfn)) {
- struct page *page = pfn_to_page(pfn);
- ClearPageReserved(page);
-
- __free_page(page);
- continue;
- }
- }
-
- printk(KERN_CRIT "%s: bad page in kernel page table\n",
- __func__);
- } 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();
}
EXPORT_SYMBOL(__dma_free_coherent);
-/*
- * Initialise the consistent memory allocation.
- */
-static int __init dma_alloc_init(void)
-{
- pgd_t *pgd;
- pud_t *pud;
- pmd_t *pmd;
- pte_t *pte;
- int ret = 0;
-
- do {
- pgd = pgd_offset(&init_mm, CONSISTENT_BASE);
- pud = pud_alloc(&init_mm, pgd, CONSISTENT_BASE);
- pmd = pmd_alloc(&init_mm, pud, CONSISTENT_BASE);
- if (!pmd) {
- printk(KERN_ERR "%s: no pmd tables\n", __func__);
- ret = -ENOMEM;
- break;
- }
-
- pte = pte_alloc_kernel(pmd, CONSISTENT_BASE);
- if (!pte) {
- printk(KERN_ERR "%s: no pte tables\n", __func__);
- ret = -ENOMEM;
- break;
- }
-
- consistent_pte = pte;
- } while (0);
-
- return ret;
-}
-
-core_initcall(dma_alloc_init);
-
/*
* make an area consistent.
*/
projects / linux-2.6-omap-h63xx.git / commitdiff