Merge tag 'arm-memremap-for-v4.7' of git://git.linaro.org/people/ard.biesheuvel/linux-arm into devel-stable

This series wires up the generic memremap() function for ARM in a way
that allows it to be used as intended, i.e., without regard for whether
the region being mapped is covered by a struct page and/or the linear
mapping (lowmem)

arch/arm/include/asm/io.h

···
 #define ioremap ioremap
 #define ioremap_nocache ioremap
 
+/*
+ * Do not use ioremap_cache for mapping memory. Use memremap instead.
+ */
 void __iomem *ioremap_cache(resource_size_t res_cookie, size_t size);
 #define ioremap_cache ioremap_cache
+
+/*
+ * Do not use ioremap_cached in new code. Provided for the benefit of
+ * the pxa2xx-flash MTD driver only.
+ */
+void __iomem *ioremap_cached(resource_size_t res_cookie, size_t size);
 
 void __iomem *ioremap_wc(resource_size_t res_cookie, size_t size);
 #define ioremap_wc ioremap_wc
···
 
 void iounmap(volatile void __iomem *iomem_cookie);
 #define iounmap iounmap
+
+void *arch_memremap_wb(phys_addr_t phys_addr, size_t size);
+#define arch_memremap_wb arch_memremap_wb
 
 /*
  * io{read,write}{16,32}be() macros

arch/arm/mm/ioremap.c

···
 	}
 
 	/*
-	 * Don't allow RAM to be mapped - this causes problems with ARMv6+
+	 * Don't allow RAM to be mapped with mismatched attributes - this
+	 * causes problems with ARMv6+
 	 */
-	if (WARN_ON(pfn_valid(pfn)))
+	if (WARN_ON(pfn_valid(pfn) && mtype != MT_MEMORY_RW))
 		return NULL;
 
 	area = get_vm_area_caller(size, VM_IOREMAP, caller);
···
 EXPORT_SYMBOL(ioremap);
 
 void __iomem *ioremap_cache(resource_size_t res_cookie, size_t size)
+	__alias(ioremap_cached);
+
+void __iomem *ioremap_cached(resource_size_t res_cookie, size_t size)
 {
 	return arch_ioremap_caller(res_cookie, size, MT_DEVICE_CACHED,
 				   __builtin_return_address(0));
 }
 EXPORT_SYMBOL(ioremap_cache);
+EXPORT_SYMBOL(ioremap_cached);
 
 void __iomem *ioremap_wc(resource_size_t res_cookie, size_t size)
 {
···
 
 	return __arm_ioremap_caller(phys_addr, size, mtype,
 			__builtin_return_address(0));
+}
+
+void *arch_memremap_wb(phys_addr_t phys_addr, size_t size)
+{
+	return (__force void *)arch_ioremap_caller(phys_addr, size,
+						   MT_MEMORY_RW,
+						   __builtin_return_address(0));
 }
 
 void __iounmap(volatile void __iomem *io_addr)

arch/arm/mm/nommu.c

···
 EXPORT_SYMBOL(ioremap);
 
 void __iomem *ioremap_cache(resource_size_t res_cookie, size_t size)
+	__alias(ioremap_cached);
+
+void __iomem *ioremap_cached(resource_size_t res_cookie, size_t size)
 {
 	return __arm_ioremap_caller(res_cookie, size, MT_DEVICE_CACHED,
 				    __builtin_return_address(0));
 }
 EXPORT_SYMBOL(ioremap_cache);
+EXPORT_SYMBOL(ioremap_cached);
 
 void __iomem *ioremap_wc(resource_size_t res_cookie, size_t size)
 {
···
 				    __builtin_return_address(0));
 }
 EXPORT_SYMBOL(ioremap_wc);
+
+void *arch_memremap_wb(phys_addr_t phys_addr, size_t size)
+{
+	return (void *)phys_addr;
+}
 
 void __iounmap(volatile void __iomem *addr)
 {

drivers/mtd/maps/pxa2xx-flash.c

···
 		       info->map.name);
 		return -ENOMEM;
 	}
-	info->map.cached = memremap(info->map.phys, info->map.size,
-			MEMREMAP_WB);
+	info->map.cached =
+		ioremap_cached(info->map.phys, info->map.size);
 	if (!info->map.cached)
 		printk(KERN_WARNING "Failed to ioremap cached %s\n",
 		       info->map.name);
···
 	map_destroy(info->mtd);
 	iounmap(info->map.virt);
 	if (info->map.cached)
-		memunmap(info->map.cached);
+		iounmap(info->map.cached);
 	kfree(info);
 	return 0;
 }

kernel/memremap.c

···
 }
 #endif
 
+#ifndef arch_memremap_wb
+static void *arch_memremap_wb(resource_size_t offset, unsigned long size)
+{
+	return (__force void *)ioremap_cache(offset, size);
+}
+#endif
+
 static void *try_ram_remap(resource_size_t offset, size_t size)
 {
 	unsigned long pfn = PHYS_PFN(offset);
···
 	/* In the simple case just return the existing linear address */
 	if (pfn_valid(pfn) && !PageHighMem(pfn_to_page(pfn)))
 		return __va(offset);
-	return NULL; /* fallback to ioremap_cache */
+	return NULL; /* fallback to arch_memremap_wb */
 }
 
 /**
···
 		if (is_ram == REGION_INTERSECTS)
 			addr = try_ram_remap(offset, size);
 		if (!addr)
-			addr = ioremap_cache(offset, size);
+			addr = arch_memremap_wb(offset, size);
 	}
 
 	/*