Commit-ID: 2ec0f0a3a4bfab90eda8b81656f62e07abf2321f Gitweb: http://git.kernel.org/tip/2ec0f0a3a4bfab90eda8b81656f62e07abf2321f Author: Ard Biesheuvel <[email protected]> AuthorDate: Wed, 17 Feb 2016 12:36:01 +0000 Committer: Ingo Molnar <[email protected]> CommitDate: Mon, 22 Feb 2016 08:26:27 +0100
efi/arm: Check for LPAE support before booting a LPAE kernel A kernel built with support for LPAE cannot boot to a state where it can inform the user about if it has to fail due to missing LPAE support in the hardware. If we happen to be booting via UEFI, we can fail gracefully so check for LPAE support in the hardware on CONFIG_ARM_LPAE builds before entering the kernel proper. Signed-off-by: Ard Biesheuvel <[email protected]> Signed-off-by: Matt Fleming <[email protected]> Reviewed-by: Jeremy Linton <[email protected]> Acked-by: Mark Rutland <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- drivers/firmware/efi/libstub/arm32-stub.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/drivers/firmware/efi/libstub/arm32-stub.c b/drivers/firmware/efi/libstub/arm32-stub.c index 495ebd6..6f42be4 100644 --- a/drivers/firmware/efi/libstub/arm32-stub.c +++ b/drivers/firmware/efi/libstub/arm32-stub.c @@ -9,6 +9,23 @@ #include <linux/efi.h> #include <asm/efi.h> +efi_status_t check_platform_features(efi_system_table_t *sys_table_arg) +{ + int block; + + /* non-LPAE kernels can run anywhere */ + if (!IS_ENABLED(CONFIG_ARM_LPAE)) + return EFI_SUCCESS; + + /* LPAE kernels need compatible hardware */ + block = cpuid_feature_extract(CPUID_EXT_MMFR0, 0); + if (block < 5) { + pr_efi_err(sys_table_arg, "This LPAE kernel is not supported by your CPU\n"); + return EFI_UNSUPPORTED; + } + return EFI_SUCCESS; +} + efi_status_t handle_kernel_image(efi_system_table_t *sys_table, unsigned long *image_addr, unsigned long *image_size,
