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

Pull x86 EFI changes from Ingo Molnar:
 "This consists of two main parts:

   - New static EFI runtime services virtual mapping layout which is
     groundwork for kexec support on EFI (Borislav Petkov)

   - EFI kexec support itself (Dave Young)"

* 'x86-efi-kexec-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
  x86/efi: parse_efi_setup() build fix
  x86: ksysfs.c build fix
  x86/efi: Delete superfluous global variables
  x86: Reserve setup_data ranges late after parsing memmap cmdline
  x86: Export x86 boot_params to sysfs
  x86: Add xloadflags bit for EFI runtime support on kexec
  x86/efi: Pass necessary EFI data for kexec via setup_data
  efi: Export EFI runtime memory mapping to sysfs
  efi: Export more EFI table variables to sysfs
  x86/efi: Cleanup efi_enter_virtual_mode() function
  x86/efi: Fix off-by-one bug in EFI Boot Services reservation
  x86/efi: Add a wrapper function efi_map_region_fixed()
  x86/efi: Remove unused variables in __map_region()
  x86/efi: Check krealloc return value
  x86/efi: Runtime services virtual mapping
  x86/mm/cpa: Map in an arbitrary pgd
  x86/mm/pageattr: Add last levels of error path
  x86/mm/pageattr: Add a PUD error unwinding path
  x86/mm/pageattr: Add a PTE pagetable populating function
  x86/mm/pageattr: Add a PMD pagetable populating function
  ...

3 files changed, 64 insertions, 19 deletions

diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h
index 65c6e6e3a552..3b978c472d08 100644
--- a/arch/x86/include/asm/efi.h
+++ b/arch/x86/include/asm/efi.h
@@ -1,6 +1,24 @@
 #ifndef _ASM_X86_EFI_H
 #define _ASM_X86_EFI_H
 
+/*
+ * We map the EFI regions needed for runtime services non-contiguously,
+ * with preserved alignment on virtual addresses starting from -4G down
+ * for a total max space of 64G. This way, we provide for stable runtime
+ * services addresses across kernels so that a kexec'd kernel can still
+ * use them.
+ *
+ * This is the main reason why we're doing stable VA mappings for RT
+ * services.
+ *
+ * This flag is used in conjuction with a chicken bit called
+ * "efi=old_map" which can be used as a fallback to the old runtime
+ * services mapping method in case there's some b0rkage with a
+ * particular EFI implementation (haha, it is hard to hold up the
+ * sarcasm here...).
+ */
+#define EFI_OLD_MEMMAP          EFI_ARCH_1
+
 #ifdef CONFIG_X86_32
 
 #define EFI_LOADER_SIGNATURE    "EL32"
@@ -69,24 +87,31 @@ extern u64 efi_call6(void *fp, u64 arg1, u64 arg2, u64 arg3,
         efi_call6((f), (u64)(a1), (u64)(a2), (u64)(a3),         \
                   (u64)(a4), (u64)(a5), (u64)(a6))
 
+#define _efi_call_virtX(x, f, ...)                                      \
+({                                                                      \
+        efi_status_t __s;                                               \
+                                                                        \
+        efi_sync_low_kernel_mappings();                                 \
+        preempt_disable();                                              \
+        __s = efi_call##x((void *)efi.systab->runtime->f, __VA_ARGS__); \
+        preempt_enable();                                               \
+        __s;                                                            \
+})
+
 #define efi_call_virt0(f)                               \
-        efi_call0((efi.systab->runtime->f))
-#define efi_call_virt1(f, a1)                                   \
-        efi_call1((efi.systab->runtime->f), (u64)(a1))
-#define efi_call_virt2(f, a1, a2)                                       \
-        efi_call2((efi.systab->runtime->f), (u64)(a1), (u64)(a2))
-#define efi_call_virt3(f, a1, a2, a3)                                   \
-        efi_call3((efi.systab->runtime->f), (u64)(a1), (u64)(a2), \
-                  (u64)(a3))
-#define efi_call_virt4(f, a1, a2, a3, a4)                               \
-        efi_call4((efi.systab->runtime->f), (u64)(a1), (u64)(a2), \
-                  (u64)(a3), (u64)(a4))
-#define efi_call_virt5(f, a1, a2, a3, a4, a5)                           \
-        efi_call5((efi.systab->runtime->f), (u64)(a1), (u64)(a2), \
-                  (u64)(a3), (u64)(a4), (u64)(a5))
-#define efi_call_virt6(f, a1, a2, a3, a4, a5, a6)                       \
-        efi_call6((efi.systab->runtime->f), (u64)(a1), (u64)(a2), \
-                  (u64)(a3), (u64)(a4), (u64)(a5), (u64)(a6))
+        _efi_call_virtX(0, f)
+#define efi_call_virt1(f, a1)                           \
+        _efi_call_virtX(1, f, (u64)(a1))
+#define efi_call_virt2(f, a1, a2)                       \
+        _efi_call_virtX(2, f, (u64)(a1), (u64)(a2))
+#define efi_call_virt3(f, a1, a2, a3)                   \
+        _efi_call_virtX(3, f, (u64)(a1), (u64)(a2), (u64)(a3))
+#define efi_call_virt4(f, a1, a2, a3, a4)               \
+        _efi_call_virtX(4, f, (u64)(a1), (u64)(a2), (u64)(a3), (u64)(a4))
+#define efi_call_virt5(f, a1, a2, a3, a4, a5)           \
+        _efi_call_virtX(5, f, (u64)(a1), (u64)(a2), (u64)(a3), (u64)(a4), (u64)(a5))
+#define efi_call_virt6(f, a1, a2, a3, a4, a5, a6)       \
+        _efi_call_virtX(6, f, (u64)(a1), (u64)(a2), (u64)(a3), (u64)(a4), (u64)(a5), (u64)(a6))
 
 extern void __iomem *efi_ioremap(unsigned long addr, unsigned long size,
                                  u32 type, u64 attribute);
@@ -95,12 +120,28 @@ extern void __iomem *efi_ioremap(unsigned long addr, unsigned long size,
 
 extern int add_efi_memmap;
 extern unsigned long x86_efi_facility;
+extern struct efi_scratch efi_scratch;
 extern void efi_set_executable(efi_memory_desc_t *md, bool executable);
 extern int efi_memblock_x86_reserve_range(void);
 extern void efi_call_phys_prelog(void);
 extern void efi_call_phys_epilog(void);
 extern void efi_unmap_memmap(void);
 extern void efi_memory_uc(u64 addr, unsigned long size);
+extern void __init efi_map_region(efi_memory_desc_t *md);
+extern void __init efi_map_region_fixed(efi_memory_desc_t *md);
+extern void efi_sync_low_kernel_mappings(void);
+extern void efi_setup_page_tables(void);
+extern void __init old_map_region(efi_memory_desc_t *md);
+
+struct efi_setup_data {
+        u64 fw_vendor;
+        u64 runtime;
+        u64 tables;
+        u64 smbios;
+        u64 reserved[8];
+};
+
+extern u64 efi_setup;
 
 #ifdef CONFIG_EFI
 
@@ -110,7 +151,7 @@ static inline bool efi_is_native(void)
 }
 
 extern struct console early_efi_console;
-
+extern void parse_efi_setup(u64 phys_addr, u32 data_len);
 #else
 /*
  * IF EFI is not configured, have the EFI calls return -ENOSYS.
@@ -122,6 +163,7 @@ extern struct console early_efi_console;
 #define efi_call4(_f, _a1, _a2, _a3, _a4)               (-ENOSYS)
 #define efi_call5(_f, _a1, _a2, _a3, _a4, _a5)          (-ENOSYS)
 #define efi_call6(_f, _a1, _a2, _a3, _a4, _a5, _a6)     (-ENOSYS)
+static inline void parse_efi_setup(u64 phys_addr, u32 data_len) {}
 #endif /* CONFIG_EFI */
 
 #endif /* _ASM_X86_EFI_H */
diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h
index 0ecac257fb26..a83aa44bb1fb 100644
--- a/arch/x86/include/asm/pgtable_types.h
+++ b/arch/x86/include/asm/pgtable_types.h
@@ -382,7 +382,8 @@ static inline void update_page_count(int level, unsigned long pages) { }
  */
 extern pte_t *lookup_address(unsigned long address, unsigned int *level);
 extern phys_addr_t slow_virt_to_phys(void *__address);
-
+extern int kernel_map_pages_in_pgd(pgd_t *pgd, u64 pfn, unsigned long address,
+                                   unsigned numpages, unsigned long page_flags);
 #endif  /* !__ASSEMBLY__ */
 
 #endif /* _ASM_X86_PGTABLE_DEFS_H */
diff --git a/arch/x86/include/uapi/asm/bootparam.h b/arch/x86/include/uapi/asm/bootparam.h
index 9c3733c5f8f7..225b0988043a 100644
--- a/arch/x86/include/uapi/asm/bootparam.h
+++ b/arch/x86/include/uapi/asm/bootparam.h
@@ -6,6 +6,7 @@
 #define SETUP_E820_EXT                  1
 #define SETUP_DTB                       2
 #define SETUP_PCI                       3
+#define SETUP_EFI                       4
 
 /* ram_size flags */
 #define RAMDISK_IMAGE_START_MASK        0x07FF
@@ -23,6 +24,7 @@
 #define XLF_CAN_BE_LOADED_ABOVE_4G      (1<<1)
 #define XLF_EFI_HANDOVER_32             (1<<2)
 #define XLF_EFI_HANDOVER_64             (1<<3)
+#define XLF_EFI_KEXEC                   (1<<4)
 
 #ifndef __ASSEMBLY__