linux-toradex.git/drivers/firmware/efi/efi.c, branch v4.9.28

efi/efivar_ssdt_load: Don't return success on allocation failure

2017-01-12T10:39:24+00:00

commit a75dcb5848359f488c32c0aef8711d9bd37a77b8 upstream.

We should return -ENOMEM here, instead of success.

Signed-off-by: Dan Carpenter 
Signed-off-by: Ard Biesheuvel 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-efi@vger.kernel.org
Fixes: 475fb4e8b2f4 ("efi / ACPI: load SSTDs from EFI variables")
Link: http://lkml.kernel.org/r/20161018143318.15673-9-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

Merge tag 'efi-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into efi/core

2016-09-13T18:21:55+00:00

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

efi: Replace runtime services spinlock with semaphore

2016-09-09T15:08:43+00:00

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 
Cc: Leif Lindholm 
Cc: Mark Rutland 
Cc: Sylvain Chouleur 
Signed-off-by: Matt Fleming

efi: Allow drivers to reserve boot services forever

2016-09-09T15:08:34+00:00

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  [kexec/kdump]
Tested-by: Ard Biesheuvel  [arm]
Acked-by: Ard Biesheuvel 
Cc: Leif Lindholm 
Cc: Peter Jones 
Cc: Borislav Petkov 
Cc: Mark Rutland 
Signed-off-by: Matt Fleming

efi: Split out EFI memory map functions into new file

2016-09-09T15:07:46+00:00

Also move the functions from the EFI fake mem driver since future
patches will require access to the memmap insertion code even if
CONFIG_EFI_FAKE_MEM isn't enabled.

This will be useful when we need to build custom EFI memory maps to
allow drivers to mark regions as reserved.

Tested-by: Dave Young  [kexec/kdump]
Tested-by: Ard Biesheuvel  [arm]
Acked-by: Ard Biesheuvel 
Cc: Leif Lindholm 
Cc: Peter Jones 
Cc: Borislav Petkov 
Cc: Mark Rutland 
Cc: Taku Izumi 
Signed-off-by: Matt Fleming

efi: Add efi_memmap_init_late() for permanent EFI memmap

2016-09-09T15:07:43+00:00

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  [kexec/kdump]
Tested-by: Ard Biesheuvel  [arm]
Acked-by: Ard Biesheuvel 
Cc: Leif Lindholm 
Cc: Peter Jones 
Cc: Borislav Petkov 
Cc: Mark Rutland 
Signed-off-by: Matt Fleming

efi: Refactor efi_memmap_init_early() into arch-neutral code

2016-09-09T15:06:38+00:00

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  [kexec/kdump]
Tested-by: Ard Biesheuvel  [arm]
Acked-by: Ard Biesheuvel 
Cc: Leif Lindholm 
Cc: Peter Jones 
Cc: Borislav Petkov 
Cc: Mark Rutland 
Signed-off-by: Matt Fleming

efi: Fix handling error value in fdt_find_uefi_params

2016-09-05T10:26:42+00:00

of_get_flat_dt_subnode_by_name can return negative value in case of error.
Assigning the result to unsigned variable and checking if the variable
is lesser than zero is incorrect and always false.
The patch fixes it by using signed variable to check the result.

The problem has been detected using semantic patch
scripts/coccinelle/tests/unsigned_lesser_than_zero.cocci

Signed-off-by: Andrzej Hajda 
Cc: Bartlomiej Zolnierkiewicz 
Cc: Marek Szyprowski 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Cc: "H. Peter Anvin" 
Cc: Shawn Lin 
Cc: Mark Rutland 
Cc: 
Signed-off-by: Matt Fleming

Merge tag 'for-linus-4.8-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

2016-07-27T18:35:37+00:00

Pull xen updates from David Vrabel:
 "Features and fixes for 4.8-rc0:

   - ACPI support for guests on ARM platforms.
   - Generic steal time support for arm and x86.
   - Support cases where kernel cpu is not Xen VCPU number (e.g., if
     in-guest kexec is used).
   - Use the system workqueue instead of a custom workqueue in various
     places"

* tag 'for-linus-4.8-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (47 commits)
  xen: add static initialization of steal_clock op to xen_time_ops
  xen/pvhvm: run xen_vcpu_setup() for the boot CPU
  xen/evtchn: use xen_vcpu_id mapping
  xen/events: fifo: use xen_vcpu_id mapping
  xen/events: use xen_vcpu_id mapping in events_base
  x86/xen: use xen_vcpu_id mapping when pointing vcpu_info to shared_info
  x86/xen: use xen_vcpu_id mapping for HYPERVISOR_vcpu_op
  xen: introduce xen_vcpu_id mapping
  x86/acpi: store ACPI ids from MADT for future usage
  x86/xen: update cpuid.h from Xen-4.7
  xen/evtchn: add IOCTL_EVTCHN_RESTRICT
  xen-blkback: really don't leak mode property
  xen-blkback: constify instance of "struct attribute_group"
  xen-blkfront: prefer xenbus_scanf() over xenbus_gather()
  xen-blkback: prefer xenbus_scanf() over xenbus_gather()
  xen: support runqueue steal time on xen
  arm/xen: add support for vm_assist hypercall
  xen: update xen headers
  xen-pciback: drop superfluous variables
  xen-pciback: short-circuit read path used for merging write values
  ...

efi / ACPI: load SSTDs from EFI variables

2016-07-08T19:52:35+00:00

This patch allows SSDTs to be loaded from EFI variables. It works by
specifying the EFI variable name containing the SSDT to be loaded. All
variables with the same name (regardless of the vendor GUID) will be
loaded.

Note that we can't use acpi_install_table and we must rely on the
dynamic ACPI table loading and bus re-scanning mechanisms. That is
because I2C/SPI controllers are initialized earlier then the EFI
subsystems and all I2C/SPI ACPI devices are enumerated when the
I2C/SPI controllers are initialized.

Signed-off-by: Octavian Purdila 
Reviewed-by: Matt Fleming 
Signed-off-by: Rafael J. Wysocki