* Enforce CONFIG_RELOCATABLE for the x86 EFI boot stub, otherwise
   it's possible to overwrite random pieces of unallocated memory during
   kernel decompression, leading to machine resets.

Resolved Conflicts:
	arch/x86/Kconfig
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Without CONFIG_RELOCATABLE the early boot code will decompress the
kernel to LOAD_PHYSICAL_ADDR. While this may have been fine in the BIOS
days, that isn't going to fly with UEFI since parts of the firmware
code/data may be located at LOAD_PHYSICAL_ADDR.

Straying outside of the bounds of the regions we've explicitly requested
from the firmware will cause all sorts of trouble. Bruno reports that
his machine resets while trying to decompress the kernel image.

We already go to great pains to ensure the kernel is loaded into a
suitably aligned buffer, it's just that the address isn't necessarily
LOAD_PHYSICAL_ADDR, because we can't guarantee that address isn't in-use
by the firmware.

Explicitly enforce CONFIG_RELOCATABLE for the EFI boot stub, so that we
can load the kernel at any address with the correct alignment.
Reported-by: NBruno Prémont <bonbons@linux-vserver.org>
Tested-by: NBruno Prémont <bonbons@linux-vserver.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Building a 32-bit kernel with CONFIG_X86_USE_3DNOW and CONFIG_EFI_STUB
leads to the following build error,

  drivers/firmware/efi/libstub/lib.a(efi-stub-helper.o): In function `efi_relocate_kernel':
  efi-stub-helper.c:(.text+0xda5): undefined reference to `_mmx_memcpy'

This is due to the fact that the EFI boot stub pulls in the 3DNow
optimized versions of the memcpy() prototype from
arch/x86/include/asm/string_32.h, even though the _mmx_memcpy()
implementation isn't available in the EFI stub.

For now, predicate CONFIG_EFI_STUB on !CONFIG_X86_USE_3DNOW. This is
most definitely a temporary fix. A complete solution will involve
selectively including kernel headers/symbols into the early-boot
execution environment of the EFI boot stub, i.e. something analogous to
the way that the _SETUP symbol is used.

Previous attempts have been made to fix this kind of problem, though
none seem to have ever been merged,

  http://lkml.kernel.org/r/20120329104822.GA17233@x1.osrc.amd.com

Clearly, this problem has been around for a long time.
Reported-by: NIngo Molnar <mingo@kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>
Link: http://lkml.kernel.org/r/1407193939-27813-1-git-send-email-matt@console-pimps.orgSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>

If we cannot resolve the virtual address of the UEFI System Table, its
physical offset must be missing from the virtual memory map, and there
is really no point in proceeding with installing the virtual memory map
and the runtime services dispatch table. So back out gracefully.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: NMark Salter <msalter@redhat.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Compiler complains in the following way when x86 32-bit kernel
with Xen support is build:

  CC      arch/x86/xen/enlighten.o
arch/x86/xen/enlighten.c: In function ‘xen_start_kernel’:
arch/x86/xen/enlighten.c:1726:3: warning: right shift count >= width of type [enabled by default]

Such line contains following EFI initialization code:

boot_params.efi_info.efi_systab_hi = (__u32)(__pa(efi_systab_xen) >> 32);

There is no issue if x86 64-bit kernel is build. However, 32-bit case
generate warning (even if that code will not be executed because Xen
does not work on 32-bit EFI platforms) due to __pa() returning unsigned long
type which has 32-bits width. So move whole EFI initialization stuff
to separate function and build it conditionally to avoid above mentioned
warning on x86 32-bit architecture.
Signed-off-by: NDaniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: NKonrad Rzeszutek Wilk <Konrad.wilk@oracle.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Add inline keyword to silence the following compiler
warnings if xen_efi_probe() is not used:

  CC      arch/x86/xen/setup.o
In file included from arch/x86/xen/xen-ops.h:7:0,
                 from arch/x86/xen/setup.c:31:
include/xen/xen-ops.h:43:35: warning: ‘xen_efi_probe’ defined but not used [-Wunused-function]
Signed-off-by: NDaniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: NKonrad Rzeszutek Wilk <Konrad.wilk@oracle.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

The EFI boot stub goes to great pains to relocate the kernel image to
an appropriately aligned address, as indicated by the ->kernel_alignment
field in the bzImage header.  However, for the PE stub entry case, we
can request that the EFI PE/COFF loader do the work for us.

Fix by exposing the desired alignment via the SectionAlignment field
in the PE/COFF headers.  Despite its name, this field provides an
overall alignment requirement for the loaded file.  (Naturally, the
FileAlignment field describes the alignment for individual sections.)

There is no way in the PE/COFF headers to express the concept of
min_alignment; we therefore do not expose the minimum (as opposed to
preferred) alignment.
Signed-off-by: NMichael Brown <mbrown@fensystems.co.uk>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Hopefully this will enable us to better debug:
https://bugzilla.kernel.org/show_bug.cgi?id=68761Signed-off-by: NUlf Winkelvos <ulf@winkelvos.de>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

The original patch is from Ben Hutchings's contribution to debian
kernel. Got Ben's permission to remove the code of efi-pstore.c and
send to linux-efi:
https://github.com/BlankOn/linux-debian/blob/master/debian/patches/features/all/efi-autoload-efivars.patch

efivars is generally useful to have on EFI systems, and in some cases
it may be impossible to load it after a kernel upgrade in order to
complete a boot loader update. At the same time we don't want to waste
memory on non-EFI systems by making them built-in.

Instead, give them module aliases as if they are platform drivers, and
register a corresponding platform device whenever EFI runtime services
are available.  This should trigger udev to load them.
Signed-off-by: NLee, Chun-Yi <jlee@suse.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Tested-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

The comment describing how struct efivars->lock is used hasn't been
updated in sync with the code. Fix it.
Reported-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Mike Waychison <mikew@google.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

efi_set_rtc_mmss() is never used to set RTC due to bugs found
on many EFI platforms. It is set directly by mach_set_rtc_mmss().
Hence, remove unused efi_set_rtc_mmss() function.
Signed-off-by: NDaniel Kiper <daniel.kiper@oracle.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

We've got constants, so let's use them instead of hard-coded values.
Signed-off-by: NDaniel Kiper <daniel.kiper@oracle.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

This patch enables EFI usage under Xen dom0. Standard EFI Linux
Kernel infrastructure cannot be used because it requires direct
access to EFI data and code. However, in dom0 case it is not possible
because above mentioned EFI stuff is fully owned and controlled
by Xen hypervisor. In this case all calls from dom0 to EFI must
be requested via special hypercall which in turn executes relevant
EFI code in behalf of dom0.

When dom0 kernel boots it checks for EFI availability on a machine.
If it is detected then artificial EFI system table is filled.
Native EFI callas are replaced by functions which mimics them
by calling relevant hypercall. Later pointer to EFI system table
is passed to standard EFI machinery and it continues EFI subsystem
initialization taking into account that there is no direct access
to EFI boot services, runtime, tables, structures, etc. After that
system runs as usual.

This patch is based on Jan Beulich and Tang Liang work.
Signed-off-by: NJan Beulich <jbeulich@suse.com>
Signed-off-by: NTang Liang <liang.tang@oracle.com>
Signed-off-by: NDaniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: NDavid Vrabel <david.vrabel@citrix.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Define constants and structures which are needed to properly
execute EFI related hypercall in Xen dom0.

This patch is based on Jan Beulich and Tang Liang work.
Signed-off-by: NJan Beulich <jbeulich@suse.com>
Signed-off-by: NTang Liang <liang.tang@oracle.com>
Signed-off-by: NDaniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: NDavid Vrabel <david.vrabel@citrix.com>
Acked-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Remove redundant set_bit(EFI_MEMMAP, &efi.flags) call.
It is executed earlier in efi_memmap_init().
Signed-off-by: NDaniel Kiper <daniel.kiper@oracle.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Remove redundant set_bit(EFI_SYSTEM_TABLES, &efi.flags) call.
It is executed earlier in efi_systab_init().
Signed-off-by: NDaniel Kiper <daniel.kiper@oracle.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Introduce EFI_PARAVIRT flag. If it is set then kernel runs
on EFI platform but it has not direct control on EFI stuff
like EFI runtime, tables, structures, etc. If not this means
that Linux Kernel has direct access to EFI infrastructure
and everything runs as usual.

This functionality is used in Xen dom0 because hypervisor
has full control on EFI stuff and all calls from dom0 to
EFI must be requested via special hypercall which in turn
executes relevant EFI code in behalf of dom0.
Signed-off-by: NDaniel Kiper <daniel.kiper@oracle.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Do not access EFI memory map if it is not available. At least
Xen dom0 EFI implementation does not have an access to it.
Signed-off-by: NDaniel Kiper <daniel.kiper@oracle.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Use early_mem*() instead of early_io*() because all mapped EFI regions
are memory (usually RAM but they could also be ROM, EPROM, EEPROM, flash,
etc.) not I/O regions. Additionally, I/O family calls do not work correctly
under Xen in our case. early_ioremap() skips the PFN to MFN conversion
when building the PTE. Using it for memory will attempt to map the wrong
machine frame. However, all artificial EFI structures created under Xen
live in dom0 memory and should be mapped/unmapped using early_mem*() family
calls which map domain memory.
Signed-off-by: NDaniel Kiper <daniel.kiper@oracle.com>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Mark Salter <msalter@redhat.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

This is odd to use early_iounmap() function do tear down mapping
created by early_memremap() function, even if it works right now,
because they belong to different set of functions. The former is
I/O related function and the later is memory related. So, create
early_memunmap() macro which in real is early_iounmap(). This
thing will help to not confuse code readers longer by mixing
functions from different classes.

EFI patches following this patch uses that functionality.
Signed-off-by: NDaniel Kiper <daniel.kiper@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

It appears that the BayTrail-T class of hardware requires EFI in order
to powerdown and reboot and no other reliable method exists.

This quirk is generally applicable to all hardware that has the ACPI
Hardware Reduced bit set, since usually ACPI would be the preferred
method.

Cc: Len Brown <len.brown@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Not only can EfiResetSystem() be used to reboot, it can also be used to
power down machines.

By and large, this functionality doesn't work very well across the range
of EFI machines in the wild, so it should definitely only be used as a
last resort. In an ideal world, this wouldn't be needed at all.

Unfortunately, we're starting to see machines where EFI is the *only*
reliable way to power down, and nothing else, not PCI, not ACPI, works.

efi_poweroff_required() should be implemented on a per-architecture
basis, since exactly when we should be using EFI runtime services is a
platform-specific decision. There's no analogue for reboot because each
architecture handles reboot very differently - the x86 code in
particular is pretty complex.

Patches to enable this for specific classes of hardware will be
submitted separately.
Tested-by: NMark Salter <msalter@redhat.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Implement efi_reboot(), which is really just a wrapper around the
EfiResetSystem() EFI runtime service, but it does at least allow us to
funnel all callers through a single location.

It also simplifies the callsites since users no longer need to check to
see whether EFI_RUNTIME_SERVICES are enabled.

Cc: Tony Luck <tony.luck@intel.com>
Tested-by: NMark Salter <msalter@redhat.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

This patch changes both x86 and arm64 efistub implementations
from #including shared .c files under drivers/firmware/efi to
building shared code as a static library.

The x86 code uses a stub built into the boot executable which
uncompresses the kernel at boot time. In this case, the library is
linked into the decompressor.

In the arm64 case, the stub is part of the kernel proper so the library
is linked into the kernel proper as well.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

The PE/COFF headers currently describe only the initialised-data
portions of the image, and result in no space being allocated for the
uninitialised-data portions.  Consequently, the EFI boot stub will end
up overwriting unexpected areas of memory, with unpredictable results.

Fix by including a .bss section in the PE/COFF headers (functionally
equivalent to the init_size field in the bzImage header).
Signed-off-by: NMichael Brown <mbrown@fensystems.co.uk>
Cc: Thomas Bächler <thomas@archlinux.org>
Cc: Josh Boyer <jwboyer@fedoraproject.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Currently, fdt_find_uefi_params() reports an error if no EFI parameters
are found in the DT. This is however a valid case for non-UEFI kernel
booting. This patch checks changes the error reporting to a
pr_info("UEFI not found") when no EFI parameters are found in the DT.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: NLeif Lindholm <leif.lindholm@linaro.org>
Tested-by: NLeif Lindholm <leif.lindholm@linaro.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

In order to move from the #include "../../../xxxxx.c" anti-pattern used
by both the x86 and arm64 versions of the stub to a static library
linked into either the kernel proper (arm64) or a separate boot
executable (x86), there is some prepatory work required.

This patch does the following:
- move forward declarations of functions shared between the arch
  specific and the generic parts of the stub to include/linux/efi.h
- move forward declarations of functions shared between various .c files
  of the generic stub code to a new local header file called "efistub.h"
- add #includes to all .c files which were formerly relying on the
  #includor to include the correct header files
- remove all static modifiers from functions which will need to be
  externally visible once we move to a static library
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

This moves definitions depended upon both by code under arch/arm64/boot
and under drivers/firmware/efi to <asm/efi.h>. This is in preparation of
turning the stub code under drivers/firmware/efi into a static library.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

This moves definitions depended upon both by code under arch/x86/boot
and under drivers/firmware/efi to <asm/efi.h>. This is in preparation of
turning the stub code under drivers/firmware/efi into a static library.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

As EFI_ERROR is not a UEFI result code but a local invention only
intended to allow get_dram_base() to signal failure, we should not use
it elsewhere.

Replace with EFI_LOAD_ERROR.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

According to the UEFI spec section 2.3.6.4, the use of FP/SIMD
instructions is allowed, and should adhere to the AAPCS64 calling
convention, which states that 'only the bottom 64 bits of each value
stored in registers v8-v15 need to be preserved' (section 5.1.2).

This applies equally to UEFI Runtime Services called by the kernel, so
make sure the FP/SIMD register file is preserved in this case. We do this
by enabling the wrappers for UEFI Runtime Services (CONFIG_EFI_RUNTIME_WRAPPERS)
and inserting calls to kernel_neon_begin()and kernel_neon_end() into
these wrappers.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

In order for other archs (such as arm64) to be able to reuse the virtual
mode function call wrappers, move them to drivers/firmware/efi/runtime-wrappers.c.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

The shared efistub code for ARM and arm64 contains a local copy of
linux_banner, allowing it to be referenced from separate executables
such as the ARM decompressor. However, this introduces a dependency on
generated header files, causing unnecessary rebuilds of the stub itself
and, in case of arm64, vmlinux which contains it.

On arm64, the copy is not actually needed since we can reference the
original symbol directly, and as it turns out, there may be better ways
to deal with this for ARM as well, so let's remove it from the shared
code. If it still needs to be reintroduced for ARM later, it should live
under arch/arm anyway and not in shared code.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

The shared efistub code for ARM and arm64 contains a local copy of
linux_banner, allowing it to be referenced from separate executables
such as the ARM decompressor. However, this introduces a dependency on
generated header files, causing unnecessary rebuilds of the stub itself
and, in case of arm64, vmlinux which contains it.

On arm64, the copy is not actually needed since we can reference the
original symbol directly, and as it turns out, there may be better ways
to deal with this for ARM as well, so let's remove it from the shared
code. If it still needs to be reintroduced for ARM later, it should live
under arch/arm anyway and not in shared code.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

In generic_id the long int timestamp is multiplied by 100000 and needs
an explicit cast to u64.

Without that the id in the resulting pstore filename is wrong and
userspace may have problems parsing it, but more importantly files in
pstore can never be deleted and may fill the EFI flash (brick device?).
This happens because when generic pstore code wants to delete a file,
it passes the id to the EFI backend which reinterpretes it and a wrong
variable name is attempted to be deleted.  There's no error message but
after remounting pstore, deleted files would reappear.
Signed-off-by: NAndrew Zaborowski <andrew.zaborowski@intel.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

This patch fixes a few compiler warning in the efi code for unused
variable, discarding const qualifier and wrong pointer type:

drivers/firmware/efi/fdt.c|66 col 22| warning: unused variable ‘name’ [-Wunused-variable]
drivers/firmware/efi/efi.c|368 col 3| warning: passing argument 3 of ‘of_get_flat_dt_prop’ from incompatible pointer type [enabled by default]
drivers/firmware/efi/efi.c|368 col 8| warning: assignment discards ‘const’ qualifier from pointer target type [enabled by default]
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

For boot efi kernel directly without bootloader.
If the kernel support XLF_CAN_BE_LOADED_ABOVE_4G, we should
not limit initrd under hdr->initrd_add_max.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

The kbuild reports the following sparse errors,

>> arch/x86/platform/efi/quirks.c:242:23: sparse: incorrect type in >> argument 1 (different address spaces)
   arch/x86/platform/efi/quirks.c:242:23:    expected void [noderef] <asn:2>*addr
   arch/x86/platform/efi/quirks.c:242:23:    got void *[assigned] tablep
>> arch/x86/platform/efi/quirks.c:245:23: sparse: incorrect type in >> argument 1 (different address spaces)
   arch/x86/platform/efi/quirks.c:245:23:    expected void [noderef] <asn:2>*addr
   arch/x86/platform/efi/quirks.c:245:23:    got struct efi_setup_data *[assigned] data

Dave Young had made previous attempts to convert the early_iounmap()
calls to early_memunmap() but ran into merge conflicts with commit
9e5c33d7 ("mm: create generic early_ioremap() support").

Now that we've got that commit in place we can switch to using
early_memunmap() since we're already using early_memremap() in
efi_reuse_config().

Cc: Dave Young <dyoung@redhat.com>
Cc: Saurabh Tangri <saurabh.tangri@intel.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Currently, it's difficult to find all the workarounds that are
applied when running on EFI, because they're littered throughout
various code paths. This change moves all of them into a separate
file with the hope that it will be come the single location for all
our well documented quirks.
Signed-off-by: NSaurabh Tangri <saurabh.tangri@intel.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>