2 files changed, 34 insertions, 20 deletions

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index c3ff82f92d9c..01f5987eb1ad 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -18,12 +18,14 @@
 #include <linux/device.h>
 #include <linux/dma-mapping.h>
 #include <linux/highmem.h>
+#include <linux/slab.h>
 
 #include <asm/memory.h>
 #include <asm/highmem.h>
 #include <asm/cacheflush.h>
 #include <asm/tlbflush.h>
 #include <asm/sizes.h>
+#include <asm/mach/arch.h>
 
 #include "mm.h"
 
@@ -117,26 +119,37 @@ static void __dma_free_buffer(struct page *page, size_t size)
 }
 
 #ifdef CONFIG_MMU
-/* Sanity check size */
-#if (CONSISTENT_DMA_SIZE % SZ_2M)
-#error "CONSISTENT_DMA_SIZE must be multiple of 2MiB"
-#endif
 
-#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)
+
+#define CONSISTENT_OFFSET(x)    (((unsigned long)(x) - consistent_base) >> PAGE_SHIFT)
+#define CONSISTENT_PTE_INDEX(x) (((unsigned long)(x) - consistent_base) >> PGDIR_SHIFT)
 
 /*
  * These are the page tables (2MB each) covering uncached, DMA consistent allocations
  */
-static pte_t *consistent_pte[NUM_CONSISTENT_PTES];
+static pte_t **consistent_pte;
+
+#define DEFAULT_CONSISTENT_DMA_SIZE SZ_2M
+
+unsigned long consistent_base = CONSISTENT_END - DEFAULT_CONSISTENT_DMA_SIZE;
+
+void __init init_consistent_dma_size(unsigned long size)
+{
+        unsigned long base = CONSISTENT_END - ALIGN(size, SZ_2M);
+
+        BUG_ON(consistent_pte); /* Check we're called before DMA region init */
+        BUG_ON(base < VMALLOC_END);
+
+        /* Grow region to accommodate specified size  */
+        if (base < consistent_base)
+                consistent_base = base;
+}
 
 #include "vmregion.h"
 
 static struct arm_vmregion_head consistent_head = {
         .vm_lock        = __SPIN_LOCK_UNLOCKED(&consistent_head.vm_lock),
         .vm_list        = LIST_HEAD_INIT(consistent_head.vm_list),
-        .vm_start       = CONSISTENT_BASE,
         .vm_end         = CONSISTENT_END,
 };
 
@@ -155,7 +168,17 @@ static int __init consistent_init(void)
         pmd_t *pmd;
         pte_t *pte;
         int i = 0;
-        u32 base = CONSISTENT_BASE;
+        unsigned long base = consistent_base;
+        unsigned long num_ptes = (CONSISTENT_END - base) >> PGDIR_SHIFT;
+
+        consistent_pte = kmalloc(num_ptes * sizeof(pte_t), GFP_KERNEL);
+        if (!consistent_pte) {
+                pr_err("%s: no memory\n", __func__);
+                return -ENOMEM;
+        }
+
+        pr_debug("DMA memory: 0x%08lx - 0x%08lx:\n", base, CONSISTENT_END);
+        consistent_head.vm_start = base;
 
         do {
                 pgd = pgd_offset(&init_mm, base);
@@ -198,7 +221,7 @@ __dma_alloc_remap(struct page *page, size_t size, gfp_t gfp, pgprot_t prot)
         size_t align;
         int bit;
 
-        if (!consistent_pte[0]) {
+        if (!consistent_pte) {
                 printk(KERN_ERR "%s: not initialised\n", __func__);
                 dump_stack();
                 return NULL;
diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index cc7e2d8be9aa..34409a08ba0d 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -653,9 +653,6 @@ void __init mem_init(void)
                         "    ITCM    : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 #endif
                         "    fixmap  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
-#ifdef CONFIG_MMU
-                        "    DMA     : 0x%08lx - 0x%08lx   (%4ld MB)\n"
-#endif
                         "    vmalloc : 0x%08lx - 0x%08lx   (%4ld MB)\n"
                         "    lowmem  : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 #ifdef CONFIG_HIGHMEM
@@ -674,9 +671,6 @@ void __init mem_init(void)
                         MLK(ITCM_OFFSET, (unsigned long) itcm_end),
 #endif
                         MLK(FIXADDR_START, FIXADDR_TOP),
-#ifdef CONFIG_MMU
-                        MLM(CONSISTENT_BASE, CONSISTENT_END),
-#endif
                         MLM(VMALLOC_START, VMALLOC_END),
                         MLM(PAGE_OFFSET, (unsigned long)high_memory),
 #ifdef CONFIG_HIGHMEM
@@ -699,9 +693,6 @@ void __init mem_init(void)
          * be detected at build time already.
          */
 #ifdef CONFIG_MMU
-        BUILD_BUG_ON(VMALLOC_END                        > CONSISTENT_BASE);
-        BUG_ON(VMALLOC_END                              > CONSISTENT_BASE);
-
         BUILD_BUG_ON(TASK_SIZE                          > MODULES_VADDR);
         BUG_ON(TASK_SIZE                                > MODULES_VADDR);
 #endif