Merge with /home/shaggy/git/linus-clean/

1 files changed, 51 insertions, 16 deletions

diff --git a/arch/arm/mm/consistent.c b/arch/arm/mm/consistent.c
index 47b0b767f080..c2ee18d2075e 100644
--- a/arch/arm/mm/consistent.c
+++ b/arch/arm/mm/consistent.c
@@ -19,17 +19,26 @@
 #include <linux/dma-mapping.h>
 
 #include <asm/cacheflush.h>
-#include <asm/io.h>
 #include <asm/tlbflush.h>
+#include <asm/sizes.h>
+
+/* Sanity check size */
+#if (CONSISTENT_DMA_SIZE % SZ_2M)
+#error "CONSISTENT_DMA_SIZE must be multiple of 2MiB"
+#endif
 
-#define CONSISTENT_BASE	(0xffc00000)
 #define CONSISTENT_END	(0xffe00000)
+#define CONSISTENT_BASE	(CONSISTENT_END - CONSISTENT_DMA_SIZE)
+
 #define CONSISTENT_OFFSET(x)	(((unsigned long)(x) - CONSISTENT_BASE) >> PAGE_SHIFT)
+#define CONSISTENT_PTE_INDEX(x) (((unsigned long)(x) - CONSISTENT_BASE) >> PGDIR_SHIFT)
+#define NUM_CONSISTENT_PTES (CONSISTENT_DMA_SIZE >> PGDIR_SHIFT)
+
 
 /*
- * This is the page table (2MB) covering uncached, DMA consistent allocations
+ * These are the page tables (2MB each) covering uncached, DMA consistent allocations
  */
-static pte_t *consistent_pte;
+static pte_t *consistent_pte[NUM_CONSISTENT_PTES];
 static DEFINE_SPINLOCK(consistent_lock);
 
 /*
@@ -66,6 +75,7 @@ struct vm_region {
 	unsigned long		vm_start;
 	unsigned long		vm_end;
 	struct page		*vm_pages;
+	int			vm_active;
 };
 
 static struct vm_region consistent_head = {
@@ -104,6 +114,7 @@ vm_region_alloc(struct vm_region *head, size_t size, gfp_t gfp)
 	list_add_tail(&new->vm_list, &c->vm_list);
 	new->vm_start = addr;
 	new->vm_end = addr + size;
+	new->vm_active = 1;
 
 	spin_unlock_irqrestore(&consistent_lock, flags);
 	return new;
@@ -120,7 +131,7 @@ static struct vm_region *vm_region_find(struct vm_region *head, unsigned long ad
 	struct vm_region *c;
 	
 	list_for_each_entry(c, &head->vm_list, vm_list) {
-		if (c->vm_start == addr)
+		if (c->vm_active && c->vm_start == addr)
 			goto out;
 	}
 	c = NULL;
@@ -141,7 +152,7 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp,
 	unsigned long order;
 	u64 mask = ISA_DMA_THRESHOLD, limit;
 
-	if (!consistent_pte) {
+	if (!consistent_pte[0]) {
 		printk(KERN_ERR "%s: not initialised\n", __func__);
 		dump_stack();
 		return NULL;
@@ -204,9 +215,12 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp,
 	c = vm_region_alloc(&consistent_head, size,
 			    gfp & ~(__GFP_DMA | __GFP_HIGHMEM));
 	if (c) {
-		pte_t *pte = consistent_pte + CONSISTENT_OFFSET(c->vm_start);
+		pte_t *pte;
 		struct page *end = page + (1 << order);
+		int idx = CONSISTENT_PTE_INDEX(c->vm_start);
+		u32 off = CONSISTENT_OFFSET(c->vm_start) & (PTRS_PER_PTE-1);
 
+		pte = consistent_pte[idx] + off;
 		c->vm_pages = page;
 
 		/*
@@ -225,6 +239,11 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp,
 			set_pte(pte, mk_pte(page, prot));
 			page++;
 			pte++;
+			off++;
+			if (off >= PTRS_PER_PTE) {
+				off = 0;
+				pte = consistent_pte[++idx];
+			}
 		} while (size -= PAGE_SIZE);
 
 		/*
@@ -319,21 +338,28 @@ EXPORT_SYMBOL(dma_mmap_writecombine);
 
 /*
  * free a page as defined by the above mapping.
+ * Must not be called with IRQs disabled.
  */
 void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr_t handle)
 {
 	struct vm_region *c;
 	unsigned long flags, addr;
 	pte_t *ptep;
+	int idx;
+	u32 off;
+
+	WARN_ON(irqs_disabled());
 
 	size = PAGE_ALIGN(size);
 
 	spin_lock_irqsave(&consistent_lock, flags);
-
 	c = vm_region_find(&consistent_head, (unsigned long)cpu_addr);
 	if (!c)
 		goto no_area;
 
+	c->vm_active = 0;
+	spin_unlock_irqrestore(&consistent_lock, flags);
+
 	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);
@@ -341,7 +367,9 @@ void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr
 		size = c->vm_end - c->vm_start;
 	}
 
-	ptep = consistent_pte + CONSISTENT_OFFSET(c->vm_start);
+	idx = CONSISTENT_PTE_INDEX(c->vm_start);
+	off = CONSISTENT_OFFSET(c->vm_start) & (PTRS_PER_PTE-1);
+	ptep = consistent_pte[idx] + off;
 	addr = c->vm_start;
 	do {
 		pte_t pte = ptep_get_and_clear(&init_mm, addr, ptep);
@@ -349,6 +377,11 @@ void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr
 
 		ptep++;
 		addr += PAGE_SIZE;
+		off++;
+		if (off >= PTRS_PER_PTE) {
+			off = 0;
+			ptep = consistent_pte[++idx];
+		}
 
 		if (!pte_none(pte) && pte_present(pte)) {
 			pfn = pte_pfn(pte);
@@ -372,8 +405,8 @@ void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr
 
 	flush_tlb_kernel_range(c->vm_start, c->vm_end);
 
+	spin_lock_irqsave(&consistent_lock, flags);
 	list_del(&c->vm_list);
-
 	spin_unlock_irqrestore(&consistent_lock, flags);
 
 	kfree(c);
@@ -395,11 +428,12 @@ static int __init consistent_init(void)
 	pgd_t *pgd;
 	pmd_t *pmd;
 	pte_t *pte;
-	int ret = 0;
+	int ret = 0, i = 0;
+	u32 base = CONSISTENT_BASE;
 
 	do {
-		pgd = pgd_offset(&init_mm, CONSISTENT_BASE);
-		pmd = pmd_alloc(&init_mm, pgd, CONSISTENT_BASE);
+		pgd = pgd_offset(&init_mm, base);
+		pmd = pmd_alloc(&init_mm, pgd, base);
 		if (!pmd) {
 			printk(KERN_ERR "%s: no pmd tables\n", __func__);
 			ret = -ENOMEM;
@@ -407,15 +441,16 @@ static int __init consistent_init(void)
 		}
 		WARN_ON(!pmd_none(*pmd));
 
-		pte = pte_alloc_kernel(pmd, CONSISTENT_BASE);
+		pte = pte_alloc_kernel(pmd, base);
 		if (!pte) {
 			printk(KERN_ERR "%s: no pte tables\n", __func__);
 			ret = -ENOMEM;
 			break;
 		}
 
-		consistent_pte = pte;
-	} while (0);
+		consistent_pte[i++] = pte;
+		base += (1 << PGDIR_SHIFT);
+	} while (base < CONSISTENT_END);
 
 	return ret;
 }