efi/x86: Move the EFI BGRT init code to early init code

Before invoking the arch specific handler, efi_mem_reserve() reserves
the given memory region through memblock.

efi_bgrt_init() will call efi_mem_reserve() after mm_init(), at which
time memblock is dead and should not be used anymore.

The EFI BGRT code depends on ACPI initialization to get the BGRT ACPI
table, so move parsing of the BGRT table to ACPI early boot code to
ensure that efi_mem_reserve() in EFI BGRT code still use memblock safely.

Tested-by: Bhupesh Sharma <bhsharma@redhat.com>
Signed-off-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-acpi@vger.kernel.org
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1485868902-20401-9-git-send-email-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 20 insertions, 8 deletions

diff --git a/drivers/acpi/bgrt.c b/drivers/acpi/bgrt.c
index 75f128e766a9..ca28aa572aa9 100644
--- a/drivers/acpi/bgrt.c
+++ b/drivers/acpi/bgrt.c
@@ -15,40 +15,41 @@
 #include <linux/sysfs.h>
 #include <linux/efi-bgrt.h>
 
+static void *bgrt_image;
 static struct kobject *bgrt_kobj;
 
 static ssize_t show_version(struct device *dev,
 			    struct device_attribute *attr, char *buf)
 {
-	return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->version);
+	return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab.version);
 }
 static DEVICE_ATTR(version, S_IRUGO, show_version, NULL);
 
 static ssize_t show_status(struct device *dev,
 			   struct device_attribute *attr, char *buf)
 {
-	return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->status);
+	return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab.status);
 }
 static DEVICE_ATTR(status, S_IRUGO, show_status, NULL);
 
 static ssize_t show_type(struct device *dev,
 			 struct device_attribute *attr, char *buf)
 {
-	return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->image_type);
+	return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab.image_type);
 }
 static DEVICE_ATTR(type, S_IRUGO, show_type, NULL);
 
 static ssize_t show_xoffset(struct device *dev,
 			    struct device_attribute *attr, char *buf)
 {
-	return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->image_offset_x);
+	return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab.image_offset_x);
 }
 static DEVICE_ATTR(xoffset, S_IRUGO, show_xoffset, NULL);
 
 static ssize_t show_yoffset(struct device *dev,
 			    struct device_attribute *attr, char *buf)
 {
-	return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->image_offset_y);
+	return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab.image_offset_y);
 }
 static DEVICE_ATTR(yoffset, S_IRUGO, show_yoffset, NULL);
 
@@ -84,15 +85,24 @@ static int __init bgrt_init(void)
 {
 	int ret;
 
-	if (!bgrt_image)
+	if (!bgrt_tab.image_address)
 		return -ENODEV;
 
+	bgrt_image = memremap(bgrt_tab.image_address, bgrt_image_size,
+			      MEMREMAP_WB);
+	if (!bgrt_image) {
+		pr_notice("Ignoring BGRT: failed to map image memory\n");
+		return -ENOMEM;
+	}
+
 	bin_attr_image.private = bgrt_image;
 	bin_attr_image.size = bgrt_image_size;
 
 	bgrt_kobj = kobject_create_and_add("bgrt", acpi_kobj);
-	if (!bgrt_kobj)
-		return -EINVAL;
+	if (!bgrt_kobj) {
+		ret = -EINVAL;
+		goto out_memmap;
+	}
 
 	ret = sysfs_create_group(bgrt_kobj, &bgrt_attribute_group);
 	if (ret)
@@ -102,6 +112,8 @@ static int __init bgrt_init(void)
 
 out_kobject:
 	kobject_put(bgrt_kobj);
+out_memmap:
+	memunmap(bgrt_image);
 	return ret;
 }
 device_initcall(bgrt_init);