ARM: fix executability of CMA mappings

The CMA region was being marked executable:

0xdc04e000-0xdc050000           8K     RW x      MEM/CACHED/WBRA
0xdc060000-0xdc100000         640K     RW x      MEM/CACHED/WBRA
0xdc4f5000-0xdc500000          44K     RW x      MEM/CACHED/WBRA
0xdcce9000-0xe0000000       52316K     RW x      MEM/CACHED/WBRA

This is mainly due to the badly worded MT_MEMORY_DMA_READY symbol, but
there are also a few other places in dma-mapping which should be
corrected to use the right constant.  Fix all these places:

0xdc04e000-0xdc050000           8K     RW NX     MEM/CACHED/WBRA
0xdc060000-0xdc100000         640K     RW NX     MEM/CACHED/WBRA
0xdc280000-0xdc300000         512K     RW NX     MEM/CACHED/WBRA
0xdc6fc000-0xe0000000       58384K     RW NX     MEM/CACHED/WBRA
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mm/dma-mapping.c

@@ -361,7 +361,7 @@ void __init init_dma_coherent_pool_size(unsigned long size)
 static int __init atomic_pool_init(void)
 {
 	struct dma_pool *pool = &atomic_pool;
-	pgprot_t prot = pgprot_dmacoherent(pgprot_kernel);
+	pgprot_t prot = pgprot_dmacoherent(PAGE_KERNEL);
 	gfp_t gfp = GFP_KERNEL | GFP_DMA;
 	unsigned long nr_pages = pool->size >> PAGE_SHIFT;
 	unsigned long *bitmap;
@@ -609,7 +609,7 @@ static void __free_from_contiguous(struct device *dev, struct page *page,
 	if (PageHighMem(page))
 		__dma_free_remap(cpu_addr, size);
 	else
-		__dma_remap(page, size, pgprot_kernel);
+		__dma_remap(page, size, PAGE_KERNEL);
 	dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT);
 }
 
@@ -1357,7 +1357,7 @@ static void __iommu_free_atomic(struct device *dev, void *cpu_addr,
 static void *arm_iommu_alloc_attrs(struct device *dev, size_t size,
 	    dma_addr_t *handle, gfp_t gfp, struct dma_attrs *attrs)
 {
-	pgprot_t prot = __get_dma_pgprot(attrs, pgprot_kernel);
+	pgprot_t prot = __get_dma_pgprot(attrs, PAGE_KERNEL);
 	struct page **pages;
 	void *addr = NULL;
 

arch/arm/mm/mmu.c

@@ -333,7 +333,8 @@ static struct mem_type mem_types[] = {
 		.domain    = DOMAIN_KERNEL,
 	},
 	[MT_MEMORY_DMA_READY] = {
-		.prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY,
+		.prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
+				L_PTE_XN,
 		.prot_l1   = PMD_TYPE_TABLE,
 		.domain    = DOMAIN_KERNEL,
 	},