Merge branch 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 EFI fixes from Peter Anvin:
 "This is a collection of fixes for the EFI support.  The controversial
  bit here is a set of patches which bumps the boot protocol version as
  part of fixing some serious problems with the EFI handover protocol,
  used when booting under EFI using a bootloader as opposed to directly
  from EFI.  These changes should also make it a lot saner to support
  cross-mode 32/64-bit EFI booting in the future.  Getting these changes
  into 3.8 means we avoid presenting an inconsistent ABI to bootloaders.

  Other changes are display detection and fixing efivarfs."

* 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, efi: remove attribute check from setup_efi_pci
  x86, build: Dynamically find entry points in compressed startup code
  x86, efi: Fix PCI ROM handing in EFI boot stub, in 32-bit mode
  x86, efi: Fix 32-bit EFI handover protocol entry point
  x86, efi: Fix display detection in EFI boot stub
  x86, boot: Define the 2.12 bzImage boot protocol
  x86/boot: Fix minor fd leakage in tools/relocs.c
  x86, efi: Set runtime_version to the EFI spec revision
  x86, efi: fix 32-bit warnings in setup_efi_pci()
  efivarfs: Delete dentry from dcache in efivarfs_file_write()
  efivarfs: Never return ENOENT from firmware
  efi, x86: Pass a proper identity mapping in efi_call_phys_prelog
  efivarfs: Drop link count of the right inode

2 files changed, 18 insertions, 6 deletions

diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 5426e482db6..77cf0090c0a 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -949,7 +949,7 @@ void __init efi_enter_virtual_mode(void)
 	 *
 	 * Call EFI services through wrapper functions.
 	 */
-	efi.runtime_version = efi_systab.fw_revision;
+	efi.runtime_version = efi_systab.hdr.revision;
 	efi.get_time = virt_efi_get_time;
 	efi.set_time = virt_efi_set_time;
 	efi.get_wakeup_time = virt_efi_get_wakeup_time;
diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c
index 95fd505dfeb..2b200386061 100644
--- a/arch/x86/platform/efi/efi_64.c
+++ b/arch/x86/platform/efi/efi_64.c
@@ -38,7 +38,7 @@
 #include <asm/cacheflush.h>
 #include <asm/fixmap.h>
 
-static pgd_t save_pgd __initdata;
+static pgd_t *save_pgd __initdata;
 static unsigned long efi_flags __initdata;
 
 static void __init early_code_mapping_set_exec(int executable)
@@ -61,12 +61,20 @@ static void __init early_code_mapping_set_exec(int executable)
 void __init efi_call_phys_prelog(void)
 {
 	unsigned long vaddress;
+	int pgd;
+	int n_pgds;
 
 	early_code_mapping_set_exec(1);
 	local_irq_save(efi_flags);
-	vaddress = (unsigned long)__va(0x0UL);
-	save_pgd = *pgd_offset_k(0x0UL);
-	set_pgd(pgd_offset_k(0x0UL), *pgd_offset_k(vaddress));
+
+	n_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT), PGDIR_SIZE);
+	save_pgd = kmalloc(n_pgds * sizeof(pgd_t), GFP_KERNEL);
+
+	for (pgd = 0; pgd < n_pgds; pgd++) {
+		save_pgd[pgd] = *pgd_offset_k(pgd * PGDIR_SIZE);
+		vaddress = (unsigned long)__va(pgd * PGDIR_SIZE);
+		set_pgd(pgd_offset_k(pgd * PGDIR_SIZE), *pgd_offset_k(vaddress));
+	}
 	__flush_tlb_all();
 }
 
@@ -75,7 +83,11 @@ void __init efi_call_phys_epilog(void)
 	/*
 	 * After the lock is released, the original page table is restored.
 	 */
-	set_pgd(pgd_offset_k(0x0UL), save_pgd);
+	int pgd;
+	int n_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT) , PGDIR_SIZE);
+	for (pgd = 0; pgd < n_pgds; pgd++)
+		set_pgd(pgd_offset_k(pgd * PGDIR_SIZE), save_pgd[pgd]);
+	kfree(save_pgd);
 	__flush_tlb_all();
 	local_irq_restore(efi_flags);
 	early_code_mapping_set_exec(0);