Merge branch 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull EFI updates from Ingo Molnar:
 "The main changes are:

   - Use separate EFI page tables when executing EFI firmware code.
     This isolates the EFI context from the rest of the kernel, which
     has security and general robustness advantages.  (Matt Fleming)

   - Run regular UEFI firmware with interrupts enabled.  This is already
     the status quo under other OSs.  (Ard Biesheuvel)

   - Various x86 EFI enhancements, such as the use of non-executable
     attributes for EFI memory mappings.  (Sai Praneeth Prakhya)

   - Various arm64 UEFI enhancements.  (Ard Biesheuvel)

   - ... various fixes and cleanups.

  The separate EFI page tables feature got delayed twice already,
  because it's an intrusive change and we didn't feel confident about
  it - third time's the charm we hope!"

* 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits)
  x86/mm/pat: Fix boot crash when 1GB pages are not supported by the CPU
  x86/efi: Only map kernel text for EFI mixed mode
  x86/efi: Map EFI_MEMORY_{XP,RO} memory region bits to EFI page tables
  x86/mm/pat: Don't implicitly allow _PAGE_RW in kernel_map_pages_in_pgd()
  efi/arm*: Perform hardware compatibility check
  efi/arm64: Check for h/w support before booting a >4 KB granular kernel
  efi/arm: Check for LPAE support before booting a LPAE kernel
  efi/arm-init: Use read-only early mappings
  efi/efistub: Prevent __init annotations from being used
  arm64/vmlinux.lds.S: Handle .init.rodata.xxx and .init.bss sections
  efi/arm64: Drop __init annotation from handle_kernel_image()
  x86/mm/pat: Use _PAGE_GLOBAL bit for EFI page table mappings
  efi/runtime-wrappers: Run UEFI Runtime Services with interrupts enabled
  efi: Reformat GUID tables to follow the format in UEFI spec
  efi: Add Persistent Memory type name
  efi: Add NV memory attribute
  x86/efi: Show actual ending addresses in efi_print_memmap
  x86/efi/bgrt: Don't ignore the BGRT if the 'valid' bit is 0
  efivars: Use to_efivar_entry
  efi: Runtime-wrapper: Get rid of the rtc_lock spinlock
  ...

4 files changed, 60 insertions, 7 deletions

diff --git a/drivers/firmware/efi/libstub/arm-stub.c b/drivers/firmware/efi/libstub/arm-stub.c
index 4deb3e7faa0e..414deb85c2e5 100644
--- a/drivers/firmware/efi/libstub/arm-stub.c
+++ b/drivers/firmware/efi/libstub/arm-stub.c
@@ -192,6 +192,10 @@ unsigned long efi_entry(void *handle, efi_system_table_t *sys_table,
 
 	pr_efi(sys_table, "Booting Linux Kernel...\n");
 
+	status = check_platform_features(sys_table);
+	if (status != EFI_SUCCESS)
+		goto fail;
+
 	/*
 	 * Get a handle to the loaded image protocol.  This is used to get
 	 * information about the running image, such as size and the command
diff --git a/drivers/firmware/efi/libstub/arm32-stub.c b/drivers/firmware/efi/libstub/arm32-stub.c
index 495ebd657e38..6f42be4d0084 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,
diff --git a/drivers/firmware/efi/libstub/arm64-stub.c b/drivers/firmware/efi/libstub/arm64-stub.c
index e0e6b74fef8f..a90f6459f5c6 100644
--- a/drivers/firmware/efi/libstub/arm64-stub.c
+++ b/drivers/firmware/efi/libstub/arm64-stub.c
@@ -12,18 +12,38 @@
 #include <linux/efi.h>
 #include <asm/efi.h>
 #include <asm/sections.h>
+#include <asm/sysreg.h>
 
 #include "efistub.h"
 
 extern bool __nokaslr;
 
-efi_status_t __init handle_kernel_image(efi_system_table_t *sys_table_arg,
-					unsigned long *image_addr,
-					unsigned long *image_size,
-					unsigned long *reserve_addr,
-					unsigned long *reserve_size,
-					unsigned long dram_base,
-					efi_loaded_image_t *image)
+efi_status_t check_platform_features(efi_system_table_t *sys_table_arg)
+{
+	u64 tg;
+
+	/* UEFI mandates support for 4 KB granularity, no need to check */
+	if (IS_ENABLED(CONFIG_ARM64_4K_PAGES))
+		return EFI_SUCCESS;
+
+	tg = (read_cpuid(ID_AA64MMFR0_EL1) >> ID_AA64MMFR0_TGRAN_SHIFT) & 0xf;
+	if (tg != ID_AA64MMFR0_TGRAN_SUPPORTED) {
+		if (IS_ENABLED(CONFIG_ARM64_64K_PAGES))
+			pr_efi_err(sys_table_arg, "This 64 KB granular kernel is not supported by your CPU\n");
+		else
+			pr_efi_err(sys_table_arg, "This 16 KB granular 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_arg,
+				 unsigned long *image_addr,
+				 unsigned long *image_size,
+				 unsigned long *reserve_addr,
+				 unsigned long *reserve_size,
+				 unsigned long dram_base,
+				 efi_loaded_image_t *image)
 {
 	efi_status_t status;
 	unsigned long kernel_size, kernel_memsize = 0;
diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h
index 5ed3d3f38166..ee49cd23ee63 100644
--- a/drivers/firmware/efi/libstub/efistub.h
+++ b/drivers/firmware/efi/libstub/efistub.h
@@ -5,6 +5,16 @@
 /* error code which can't be mistaken for valid address */
 #define EFI_ERROR	(~0UL)
 
+/*
+ * __init annotations should not be used in the EFI stub, since the code is
+ * either included in the decompressor (x86, ARM) where they have no effect,
+ * or the whole stub is __init annotated at the section level (arm64), by
+ * renaming the sections, in which case the __init annotation will be
+ * redundant, and will result in section names like .init.init.text, and our
+ * linker script does not expect that.
+ */
+#undef __init
+
 void efi_char16_printk(efi_system_table_t *, efi_char16_t *);
 
 efi_status_t efi_open_volume(efi_system_table_t *sys_table_arg, void *__image,
@@ -50,4 +60,6 @@ efi_status_t efi_random_alloc(efi_system_table_t *sys_table_arg,
 			      unsigned long size, unsigned long align,
 			      unsigned long *addr, unsigned long random_seed);
 
+efi_status_t check_platform_features(efi_system_table_t *sys_table_arg);
+
 #endif