efi/apple-properties: Use memremap() instead of ioremap()

The memory we are accessing through virtual address has no IO side
effects. Moreover, for IO memory we have to use special accessors,
which we don't use.

Due to above, convert the driver to use memremap() instead of ioremap().

Tested-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20180308080020.22828-12-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

drivers/firmware/efi/apple-properties.c

@@ -19,6 +19,7 @@
 
 #include <linux/bootmem.h>
 #include <linux/efi.h>
+#include <linux/io.h>
 #include <linux/platform_data/x86/apple.h>
 #include <linux/property.h>
 #include <linux/slab.h>
@@ -189,7 +190,7 @@ static int __init map_properties(void)
 
 	pa_data = boot_params.hdr.setup_data;
 	while (pa_data) {
-		data = ioremap(pa_data, sizeof(*data));
+		data = memremap(pa_data, sizeof(*data), MEMREMAP_WB);
 		if (!data) {
 			pr_err("cannot map setup_data header\n");
 			return -ENOMEM;
@@ -197,14 +198,14 @@ static int __init map_properties(void)
 
 		if (data->type != SETUP_APPLE_PROPERTIES) {
 			pa_data = data->next;
-			iounmap(data);
+			memunmap(data);
 			continue;
 		}
 
 		data_len = data->len;
-		iounmap(data);
+		memunmap(data);
 
-		data = ioremap(pa_data, sizeof(*data) + data_len);
+		data = memremap(pa_data, sizeof(*data) + data_len, MEMREMAP_WB);
 		if (!data) {
 			pr_err("cannot map setup_data payload\n");
 			return -ENOMEM;
@@ -229,7 +230,7 @@ static int __init map_properties(void)
 		 * to avoid breaking the chain of ->next pointers.
 		 */
 		data->len = 0;
-		iounmap(data);
+		memunmap(data);
 		free_bootmem_late(pa_data + sizeof(*data), data_len);
 
 		return ret;