efi/arm: Revert deferred unmap of early memmap mapping
[ Upstream commit 33412b8673135b18ea42beb7f5117ed0091798b6 ]
Commit:
3ea86495aef2 ("efi/arm: preserve early mapping of UEFI memory map longer for BGRT")
deferred the unmap of the early mapping of the UEFI memory map to
accommodate the ACPI BGRT code, which looks up the memory type that
backs the BGRT table to validate it against the requirements of the UEFI spec.
Unfortunately, this causes problems on ARM, which does not permit
early mappings to persist after paging_init() is called, resulting
in a WARN() splat. Since we don't support the BGRT table on ARM anway,
let's revert ARM to the old behaviour, which is to take down the
early mapping at the end of efi_init().
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Fixes: 3ea86495aef2 ("efi/arm: preserve early mapping of UEFI memory ...")
Link: http://lkml.kernel.org/r/20181114175544.12860-3-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
diff --git a/drivers/firmware/efi/arm-init.c b/drivers/firmware/efi/arm-init.c
index a7c522e..312f9f3 100644
--- a/drivers/firmware/efi/arm-init.c
+++ b/drivers/firmware/efi/arm-init.c
@@ -265,6 +265,10 @@
(params.mmap & ~PAGE_MASK)));
init_screen_info();
+
+ /* ARM does not permit early mappings to persist across paging_init() */
+ if (IS_ENABLED(CONFIG_ARM))
+ efi_memmap_unmap();
}
static int __init register_gop_device(void)
diff --git a/drivers/firmware/efi/arm-runtime.c b/drivers/firmware/efi/arm-runtime.c
index 8995a48..ad1530a 100644
--- a/drivers/firmware/efi/arm-runtime.c
+++ b/drivers/firmware/efi/arm-runtime.c
@@ -122,7 +122,7 @@
{
u64 mapsize;
- if (!efi_enabled(EFI_BOOT) || !efi_enabled(EFI_MEMMAP)) {
+ if (!efi_enabled(EFI_BOOT)) {
pr_info("EFI services will not be available.\n");
return 0;
}
diff --git a/drivers/firmware/efi/memmap.c b/drivers/firmware/efi/memmap.c
index 5fc7052..1907db2 100644
--- a/drivers/firmware/efi/memmap.c
+++ b/drivers/firmware/efi/memmap.c
@@ -118,6 +118,9 @@
void __init efi_memmap_unmap(void)
{
+ if (!efi_enabled(EFI_MEMMAP))
+ return;
+
if (!efi.memmap.late) {
unsigned long size;