1 files changed, 41 insertions, 67 deletions

diff --git a/arch/powerpc/mm/dma-noncoherent.c b/arch/powerpc/mm/dma-noncoherent.c
index b7dc4c19f582..36692f5c9a76 100644
--- a/arch/powerpc/mm/dma-noncoherent.c
+++ b/arch/powerpc/mm/dma-noncoherent.c
@@ -32,20 +32,21 @@
 
 #include <asm/tlbflush.h>
 
+#include "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 (CONFIG_CONSISTENT_START)
-#define CONSISTENT_END  (CONFIG_CONSISTENT_START + CONFIG_CONSISTENT_SIZE)
+#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 pte_t *consistent_pte;
 static DEFINE_SPINLOCK(consistent_lock);
 
 /*
@@ -148,22 +149,38 @@ static struct ppc_vm_region *ppc_vm_region_find(struct ppc_vm_region *head, unsi
  * virtual and bus address for that space.
  */
 void *
-__dma_alloc_coherent(size_t size, dma_addr_t *handle, gfp_t gfp)
+__dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp)
 {
         struct page *page;
         struct ppc_vm_region *c;
         unsigned long order;
-        u64 mask = 0x00ffffff, limit; /* ISA default */
+        u64 mask = ISA_DMA_THRESHOLD, limit;
 
-        if (!consistent_pte) {
-                printk(KERN_ERR "%s: not initialised\n", __func__);
-                dump_stack();
-                return NULL;
+        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)) {
+        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;
@@ -171,6 +188,7 @@ __dma_alloc_coherent(size_t size, dma_addr_t *handle, gfp_t gfp)
 
         order = get_order(size);
 
+        /* Might be useful if we ever have a real legacy DMA zone... */
         if (mask != 0xffffffff)
                 gfp |= GFP_DMA;
 
@@ -195,7 +213,6 @@ __dma_alloc_coherent(size_t size, dma_addr_t *handle, gfp_t gfp)
                             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);
@@ -206,13 +223,10 @@ __dma_alloc_coherent(size_t size, dma_addr_t *handle, gfp_t gfp)
                 *handle = page_to_phys(page);
 
                 do {
-                        BUG_ON(!pte_none(*pte));
-
                         SetPageReserved(page);
-                        set_pte_at(&init_mm, vaddr,
-                                   pte, mk_pte(page, pgprot_noncached(PAGE_KERNEL)));
+                        map_page(vaddr, page_to_phys(page),
+                                 pgprot_noncached(PAGE_KERNEL));
                         page++;
-                        pte++;
                         vaddr += PAGE_SIZE;
                 } while (size -= PAGE_SIZE);
 
@@ -241,8 +255,7 @@ 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);
@@ -258,29 +271,26 @@ void __dma_free_coherent(size_t size, void *vaddr)
                 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);
+                pte_t *ptep;
                 unsigned long pfn;
 
-                ptep++;
-                addr += PAGE_SIZE;
-
-                if (!pte_none(pte) && pte_present(pte)) {
-                        pfn = pte_pfn(pte);
-
+                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);
-                                ClearPageReserved(page);
 
+                                ClearPageReserved(page);
                                 __free_page(page);
-                                continue;
                         }
                 }
-
-                printk(KERN_CRIT "%s: bad page in kernel page table\n",
-                       __func__);
+                addr += PAGE_SIZE;
         } while (size -= PAGE_SIZE);
 
         flush_tlb_kernel_range(c->vm_start, c->vm_end);
@@ -301,42 +311,6 @@ void __dma_free_coherent(size_t size, void *vaddr)
 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.
  */
 void __dma_sync(void *vaddr, size_t size, int direction)