path: root/Documentation
diff options
authorLinus Torvalds <torvalds@linux-foundation.org>2014-01-20 12:05:30 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2014-01-20 12:05:30 -0800
commit972d5e7e5b66f5a143026fcdd4b2be2f519c0f12 (patch)
tree6c1c5bb79fe163b3b48254605b54532099b74cff /Documentation
parent5d4863e4cc4dc12d1d5e42da3cb5d38c535e4ad6 (diff)
parentef0b8b9a521c65201bfca9747ee1bf374296133c (diff)
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 ...
Diffstat (limited to 'Documentation')
6 files changed, 108 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-firmware-efi b/Documentation/ABI/testing/sysfs-firmware-efi
new file mode 100644
index 000000000000..05874da7ce80
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-firmware-efi
@@ -0,0 +1,20 @@
+What: /sys/firmware/efi/fw_vendor
+Date: December 2013
+Contact: Dave Young <dyoung@redhat.com>
+Description: It shows the physical address of firmware vendor field in the
+ EFI system table.
+Users: Kexec
+What: /sys/firmware/efi/runtime
+Date: December 2013
+Contact: Dave Young <dyoung@redhat.com>
+Description: It shows the physical address of runtime service table entry in
+ the EFI system table.
+Users: Kexec
+What: /sys/firmware/efi/config_table
+Date: December 2013
+Contact: Dave Young <dyoung@redhat.com>
+Description: It shows the physical address of config table entry in the EFI
+ system table.
+Users: Kexec
diff --git a/Documentation/ABI/testing/sysfs-firmware-efi-runtime-map b/Documentation/ABI/testing/sysfs-firmware-efi-runtime-map
new file mode 100644
index 000000000000..c61b9b348e99
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-firmware-efi-runtime-map
@@ -0,0 +1,34 @@
+What: /sys/firmware/efi/runtime-map/
+Date: December 2013
+Contact: Dave Young <dyoung@redhat.com>
+Description: Switching efi runtime services to virtual mode requires
+ that all efi memory ranges which have the runtime attribute
+ bit set to be mapped to virtual addresses.
+ The efi runtime services can only be switched to virtual
+ mode once without rebooting. The kexec kernel must maintain
+ the same physical to virtual address mappings as the first
+ kernel. The mappings are exported to sysfs so userspace tools
+ can reassemble them and pass them into the kexec kernel.
+ /sys/firmware/efi/runtime-map/ is the directory the kernel
+ exports that information in.
+ subdirectories are named with the number of the memory range:
+ /sys/firmware/efi/runtime-map/0
+ /sys/firmware/efi/runtime-map/1
+ /sys/firmware/efi/runtime-map/2
+ /sys/firmware/efi/runtime-map/3
+ ...
+ Each subdirectory contains five files:
+ attribute : The attributes of the memory range.
+ num_pages : The size of the memory range in pages.
+ phys_addr : The physical address of the memory range.
+ type : The type of the memory range.
+ virt_addr : The virtual address of the memory range.
+ Above values are all hexadecimal numbers with the '0x' prefix.
+Users: Kexec
diff --git a/Documentation/ABI/testing/sysfs-kernel-boot_params b/Documentation/ABI/testing/sysfs-kernel-boot_params
new file mode 100644
index 000000000000..eca38ce2852d
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-kernel-boot_params
@@ -0,0 +1,38 @@
+What: /sys/kernel/boot_params
+Date: December 2013
+Contact: Dave Young <dyoung@redhat.com>
+Description: The /sys/kernel/boot_params directory contains two
+ files: "data" and "version" and one subdirectory "setup_data".
+ It is used to export the kernel boot parameters of an x86
+ platform to userspace for kexec and debugging purpose.
+ If there's no setup_data in boot_params the subdirectory will
+ not be created.
+ "data" file is the binary representation of struct boot_params.
+ "version" file is the string representation of boot
+ protocol version.
+ "setup_data" subdirectory contains the setup_data data
+ structure in boot_params. setup_data is maintained in kernel
+ as a link list. In "setup_data" subdirectory there's one
+ subdirectory for each link list node named with the number
+ of the list nodes. The list node subdirectory contains two
+ files "type" and "data". "type" file is the string
+ representation of setup_data type. "data" file is the binary
+ representation of setup_data payload.
+ The whole boot_params directory structure is like below:
+ /sys/kernel/boot_params
+ |__ data
+ |__ setup_data
+ | |__ 0
+ | | |__ data
+ | | |__ type
+ | |__ 1
+ | |__ data
+ | |__ type
+ |__ version
+Users: Kexec
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 3b8e262c3657..4eb5fff022b4 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -899,6 +899,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
edd= [EDD]
Format: {"off" | "on" | "skip[mbr]"}
+ efi= [EFI]
+ Format: { "old_map" }
+ old_map [X86-64]: switch to the old ioremap-based EFI
+ runtime services mapping. 32-bit still uses this one by
+ default.
efi_no_storage_paranoia [EFI; X86]
Using this parameter you can use more than 50% of
your efi variable storage. Use this parameter only if
diff --git a/Documentation/x86/boot.txt b/Documentation/x86/boot.txt
index f4f268c2b826..cb81741d3b0b 100644
--- a/Documentation/x86/boot.txt
+++ b/Documentation/x86/boot.txt
@@ -608,6 +608,9 @@ Protocol: 2.12+
- If 1, the kernel supports the 64-bit EFI handoff entry point
given at handover_offset + 0x200.
+ Bit 4 (read): XLF_EFI_KEXEC
+ - If 1, the kernel supports kexec EFI boot with EFI runtime support.
Field name: cmdline_size
Type: read
Offset/size: 0x238/4
diff --git a/Documentation/x86/x86_64/mm.txt b/Documentation/x86/x86_64/mm.txt
index 881582f75c9c..c584a51add15 100644
--- a/Documentation/x86/x86_64/mm.txt
+++ b/Documentation/x86/x86_64/mm.txt
@@ -28,4 +28,11 @@ reference.
Current X86-64 implementations only support 40 bits of address space,
but we support up to 46 bits. This expands into MBZ space in the page tables.
+We map EFI runtime services in the aforementioned PGD in the virtual
+range of 64Gb (arbitrarily set, can be raised if needed)
+0xffffffef00000000 - 0xffffffff00000000
-Andi Kleen, Jul 2004