Pull EFI updates from Matt Fleming:
"* Refactor the EFI memory map code into architecture neutral files
and allow drivers to permanently reserve EFI boot services regions
on x86, as well as ARM/arm64 - Matt Fleming
* Add ARM support for the EFI esrt driver - Ard Biesheuvel
* Make the EFI runtime services and efivar API interruptible by
swapping spinlocks for semaphores - Sylvain Chouleur
* Provide the EFI identity mapping for kexec which allows kexec to
work on SGI/UV platforms with requiring the "noefi" kernel command
line parameter - Alex Thorlton
* Add debugfs node to dump EFI page tables on arm64 - Ard Biesheuvel
* Merge the EFI test driver being carried out of tree until now in
the FWTS project - Ivan Hu
* Expand the list of flags for classifying EFI regions as "RAM" on
arm64 so we align with the UEFI spec - Ard Biesheuvel
* Optimise out the EFI mixed mode if it's unsupported (CONFIG_X86_32)
or disabled (CONFIG_EFI_MIXED=n) and switch the early EFI boot
services function table for direct calls, alleviating us from
having to maintain the custom function table - Lukas Wunner
* Miscellaneous cleanups and fixes"
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The purpose of the efi_runtime_lock is to prevent concurrent calls into
the firmware. There is no need to use spinlocks here, as long as we ensure
that runtime service invocations from an atomic context (i.e., EFI pstore)
cannot block.
So use a semaphore instead, and use down_trylock() in the nonblocking case.
We don't use a mutex here because the mutex_trylock() function must not
be called from interrupt context, whereas the down_trylock() can.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Sylvain Chouleur <sylvain.chouleur@gmail.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
All efivars operations are protected by a spinlock which prevents
interruptions and preemption. This is too restricted, we just need a
lock preventing concurrency.
The idea is to use a semaphore of count 1 and to have two ways of
locking, depending on the context:
- In interrupt context, we call down_trylock(), if it fails we return
an error
- In normal context, we call down_interruptible()
We don't use a mutex here because the mutex_trylock() function must not
be called from interrupt context, whereas the down_trylock() can.
Signed-off-by: Sylvain Chouleur <sylvain.chouleur@intel.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Sylvain Chouleur <sylvain.chouleur@gmail.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
This patch replaces the spinlock in the efivars struct with a single lock
for the whole vars.c file. The goal of this lock is to protect concurrent
calls to efi variable services, registering and unregistering. This allows
us to register new efivars operations without having in-progress call.
Signed-off-by: Sylvain Chouleur <sylvain.chouleur@intel.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Sylvain Chouleur <sylvain.chouleur@gmail.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Now that efi.memmap is available all of the time there's no need to
allocate and build a separate copy of the EFI memory map.
Furthermore, efi.memmap contains boot services regions but only those
regions that have been reserved via efi_mem_reserve(). Using
efi.memmap allows us to pass boot services across kexec reboot so that
the ESRT and BGRT drivers will now work.
Tested-by: Dave Young <dyoung@redhat.com> [kexec/kdump]
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [arm]
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Peter Jones <pjones@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Today, it is not possible for drivers to reserve EFI boot services for
access after efi_free_boot_services() has been called on x86. For
ARM/arm64 it can be done simply by calling memblock_reserve().
Having this ability for all three architectures is desirable for a
couple of reasons,
1) It saves drivers copying data out of those regions
2) kexec reboot can now make use of things like ESRT
Instead of using the standard memblock_reserve() which is insufficient
to reserve the region on x86 (see efi_reserve_boot_services()), a new
API is introduced in this patch; efi_mem_reserve().
efi.memmap now always represents which EFI memory regions are
available. On x86 the EFI boot services regions that have not been
reserved via efi_mem_reserve() will be removed from efi.memmap during
efi_free_boot_services().
This has implications for kexec, since it is not possible for a newly
kexec'd kernel to access the same boot services regions that the
initial boot kernel had access to unless they are reserved by every
kexec kernel in the chain.
Tested-by: Dave Young <dyoung@redhat.com> [kexec/kdump]
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [arm]
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Peter Jones <pjones@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
While efi_memmap_init_{early,late}() exist for architecture code to
install memory maps from firmware data and for the virtual memory
regions respectively, drivers don't care which stage of the boot we're
at and just want to swap the existing memmap for a modified one.
efi_memmap_install() abstracts the details of how the new memory map
should be mapped and the existing one unmapped.
Tested-by: Dave Young <dyoung@redhat.com> [kexec/kdump]
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [arm]
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Peter Jones <pjones@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Taku Izumi <izumi.taku@jp.fujitsu.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Drivers need a way to access the EFI memory map at runtime. ARM and
arm64 currently provide this by remapping the EFI memory map into the
vmalloc space before setting up the EFI virtual mappings.
x86 does not provide this functionality which has resulted in the code
in efi_mem_desc_lookup() where it will manually map individual EFI
memmap entries if the memmap has already been torn down on x86,
/*
* If a driver calls this after efi_free_boot_services,
* ->map will be NULL, and the target may also not be mapped.
* So just always get our own virtual map on the CPU.
*
*/
md = early_memremap(p, sizeof (*md));
There isn't a good reason for not providing a permanent EFI memory map
for runtime queries, especially since the EFI regions are not mapped
into the standard kernel page tables.
Tested-by: Dave Young <dyoung@redhat.com> [kexec/kdump]
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [arm]
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Peter Jones <pjones@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Every EFI architecture apart from ia64 needs to setup the EFI memory
map at efi.memmap, and the code for doing that is essentially the same
across all implementations. Therefore, it makes sense to factor this
out into the common code under drivers/firmware/efi/.
The only slight variation is the data structure out of which we pull
the initial memory map information, such as physical address, memory
descriptor size and version, etc. We can address this by passing a
generic data structure (struct efi_memory_map_data) as the argument to
efi_memmap_init_early() which contains the minimum info required for
initialising the memory map.
In the process, this patch also fixes a few undesirable implementation
differences:
- ARM and arm64 were failing to clear the EFI_MEMMAP bit when
unmapping the early EFI memory map. EFI_MEMMAP indicates whether
the EFI memory map is mapped (not the regions contained within) and
can be traversed. It's more correct to set the bit as soon as we
memremap() the passed in EFI memmap.
- Rename efi_unmmap_memmap() to efi_memmap_unmap() to adhere to the
regular naming scheme.
This patch also uses a read-write mapping for the memory map instead
of the read-only mapping currently used on ARM and arm64. x86 needs
the ability to update the memory map in-place when assigning virtual
addresses to regions (efi_map_region()) and tagging regions when
reserving boot services (efi_reserve_boot_services()).
There's no way for the generic fake_mem code to know which mapping to
use without introducing some arch-specific constant/hook, so just use
read-write since read-only is of dubious value for the EFI memory map.
Tested-by: Dave Young <dyoung@redhat.com> [kexec/kdump]
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [arm]
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Peter Jones <pjones@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
The spec allows ExitBootServices to fail with EFI_INVALID_PARAMETER if a
race condition has occurred where the EFI has updated the memory map after
the stub grabbed a reference to the map. The spec defines a retry
proceedure with specific requirements to handle this scenario.
This scenario was previously observed on x86 - commit d3768d885c ("x86,
efi: retry ExitBootServices() on failure") but the current fix is not spec
compliant and the scenario is now observed on the Qualcomm Technologies
QDF2432 via the FDT stub which does not handle the error and thus causes
boot failures. The user will notice the boot failure as the kernel is not
executed and the system may drop back to a UEFI shell, but will be
unresponsive to input and the system will require a power cycle to recover.
Add a helper to the stub library that correctly adheres to the spec in the
case of EFI_INVALID_PARAMETER from ExitBootServices and can be universally
used across all stub implementations.
Signed-off-by: Jeffrey Hugo <jhugo@codeaurora.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
efi_get_memory_map() allocates a buffer to store the memory map that it
retrieves. This buffer may need to be reused by the client after
ExitBootServices() is called, at which point allocations are not longer
permitted. To support this usecase, provide the allocated buffer size back
to the client, and allocate some additional headroom to account for any
reasonable growth in the map that is likely to happen between the call to
efi_get_memory_map() and the client reusing the buffer.
Signed-off-by: Jeffrey Hugo <jhugo@codeaurora.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Pull ia64 updates from Tony Luck:
"Miscellaneous ia64 cleanups"
* tag 'please-pull-misc-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux:
ia64: salinfo: use a waitqueue instead a sema down/up combo
ia64: efi: use timespec64 for persistent clock
This commit makes a few slight modifications to the efi_call_virt() macro
to get it to work with function pointers that are stored in locations
other than efi.systab->runtime, and renames the macro to
efi_call_virt_pointer(). The majority of the changes here are to pull
these macros up into header files so that they can be accessed from
outside of drivers/firmware/efi/runtime-wrappers.c.
The most significant change not directly related to the code move is to
add an extra "p" argument into the appropriate efi_call macros, and use
that new argument in place of the, formerly hard-coded,
efi.systab->runtime pointer.
The last piece of the puzzle was to add an efi_call_virt() macro back into
drivers/firmware/efi/runtime-wrappers.c to wrap around the new
efi_call_virt_pointer() macro - this was mainly to keep the code from
looking too cluttered by adding a bunch of extra references to
efi.systab->runtime everywhere.
Note that I also broke up the code in the efi_call_virt_pointer() macro a
bit in the process of moving it.
Signed-off-by: Alex Thorlton <athorlton@sgi.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dimitri Sivanich <sivanich@sgi.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roy Franz <roy.franz@linaro.org>
Cc: Russ Anderson <rja@sgi.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1466839230-12781-5-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We have a generic read_persistent_clock64 interface now, and can
change the ia64 implementation to provide that instead of
read_persistent_clock.
The main point of this is to avoid the use of struct timespec
in the global efi.h, which would cause build errors as soon
as we want to build a kernel without 'struct timespec' defined
on 32-bit architectures.
Aside from this, we get a little closer to removing the
__weak read_persistent_clock() definition, which relies on
converting all architectures to provide read_persistent_clock64
instead.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Commit:
78ce248faa ("efi: Iterate over efi.memmap in for_each_efi_memory_desc()")
introduced a regression for systems booted with the 'noefi' kernel option.
In particular, I observed an early kernel hang in efi_find_mirror()'s
for_each_efi_memory_desc() call. As we don't have efi memmap on this
system we enter this iterator with the following parameters:
efi.memmap.map = 0, efi.memmap.map_end = 0, efi.memmap.desc_size = 28
... then for_each_efi_memory_desc_in_map() does the following comparison:
(md) <= (efi_memory_desc_t *)((m)->map_end - (m)->desc_size);
... where md = 0, (m)->map_end = 0 and (m)->desc_size = 28 but when we subtract
something from a NULL pointer wrap around happens and we end up returning
invalid pointer and crash.
Fix it by using the correct pointer arithmetics.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Salter <msalter@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Fixes: 78ce248faa ("efi: Iterate over efi.memmap in for_each_efi_memory_desc()")
Link: http://lkml.kernel.org/r/1464690224-4503-2-git-send-email-matt@codeblueprint.co.uk
[ Made the changelog more readable. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The EFI capsule mechanism allows data blobs to be passed to the EFI
firmware. A common use case is performing firmware updates. This patch
just introduces the main infrastructure for interacting with the
firmware, and a driver that allows users to upload capsules will come
in a later patch.
Once a capsule has been passed to the firmware, the next reboot must
be performed using the ResetSystem() EFI runtime service, which may
involve overriding the reboot type specified by reboot=. This ensures
the reset value returned by QueryCapsuleCapabilities() is used to
reset the system, which is required for the capsule to be processed.
efi_capsule_pending() is provided for this purpose.
At the moment we only allow a single capsule blob to be sent to the
firmware despite the fact that UpdateCapsule() takes a 'CapsuleCount'
parameter. This simplifies the API and shouldn't result in any
downside since it is still possible to send multiple capsules by
repeatedly calling UpdateCapsule().
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Bryan O'Donoghue <pure.logic@nexus-software.ie>
Cc: Kweh Hock Leong <hock.leong.kweh@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Peter Jones <pjones@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: joeyli <jlee@suse.com>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1461614832-17633-28-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
