linux-toradex.git/include/linux/efi.h, branch v3.8.12

efi: Make 'efi_enabled' a function to query EFI facilities

2013-01-30T19:51:59+00:00

Originally 'efi_enabled' indicated whether a kernel was booted from
EFI firmware. Over time its semantics have changed, and it now
indicates whether or not we are booted on an EFI machine with
bit-native firmware, e.g. 64-bit kernel with 64-bit firmware.

The immediate motivation for this patch is the bug report at,

    https://bugs.launchpad.net/ubuntu-cdimage/+bug/1040557

which details how running a platform driver on an EFI machine that is
designed to run under BIOS can cause the machine to become
bricked. Also, the following report,

    https://bugzilla.kernel.org/show_bug.cgi?id=47121

details how running said driver can also cause Machine Check
Exceptions. Drivers need a new means of detecting whether they're
running on an EFI machine, as sadly the expression,

    if (!efi_enabled)

hasn't been a sufficient condition for quite some time.

Users actually want to query 'efi_enabled' for different reasons -
what they really want access to is the list of available EFI
facilities.

For instance, the x86 reboot code needs to know whether it can invoke
the ResetSystem() function provided by the EFI runtime services, while
the ACPI OSL code wants to know whether the EFI config tables were
mapped successfully. There are also checks in some of the platform
driver code to simply see if they're running on an EFI machine (which
would make it a bad idea to do BIOS-y things).

This patch is a prereq for the samsung-laptop fix patch.

Cc: David Airlie 
Cc: Corentin Chary 
Cc: Matthew Garrett 
Cc: Dave Jiang 
Cc: Olof Johansson 
Cc: Peter Jones 
Cc: Colin Ian King 
Cc: Steve Langasek 
Cc: Tony Luck 
Cc: Konrad Rzeszutek Wilk 
Cc: Rafael J. Wysocki 
Cc: 
Signed-off-by: Matt Fleming 
Signed-off-by: H. Peter Anvin

Revert "x86-64/efi: Use EFI to deal with platform wall clock (again)"

2012-12-15T23:20:41+00:00

This reverts commit bd52276fa1d4 ("x86-64/efi: Use EFI to deal with
platform wall clock (again)"), and the two supporting commits:

  da5a108d05b4: "x86/kernel: remove tboot 1:1 page table creation code"

  185034e72d59: "x86, efi: 1:1 pagetable mapping for virtual EFI calls")

as they all depend semantically on commit 53b87cf088e2 ("x86, mm:
Include the entire kernel memory map in trampoline_pgd") that got
reverted earlier due to the problems it caused.

This was pointed out by Yinghai Lu, and verified by me on my Macbook Air
that uses EFI.

Pointed-out-by: Yinghai Lu 
Signed-off-by: Linus Torvalds

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

2012-12-14T18:08:40+00:00

Pull x86 EFI update from Peter Anvin:
 "EFI tree, from Matt Fleming.  Most of the patches are the new efivarfs
  filesystem by Matt Garrett & co.  The balance are support for EFI
  wallclock in the absence of a hardware-specific driver, and various
  fixes and cleanups."

* 'core-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
  efivarfs: Make efivarfs_fill_super() static
  x86, efi: Check table header length in efi_bgrt_init()
  efivarfs: Use query_variable_info() to limit kmalloc()
  efivarfs: Fix return value of efivarfs_file_write()
  efivarfs: Return a consistent error when efivarfs_get_inode() fails
  efivarfs: Make 'datasize' unsigned long
  efivarfs: Add unique magic number
  efivarfs: Replace magic number with sizeof(attributes)
  efivarfs: Return an error if we fail to read a variable
  efi: Clarify GUID length calculations
  efivarfs: Implement exclusive access for {get,set}_variable
  efivarfs: efivarfs_fill_super() ensure we clean up correctly on error
  efivarfs: efivarfs_fill_super() ensure we free our temporary name
  efivarfs: efivarfs_fill_super() fix inode reference counts
  efivarfs: efivarfs_create() ensure we drop our reference on inode on error
  efivarfs: efivarfs_file_read ensure we free data in error paths
  x86-64/efi: Use EFI to deal with platform wall clock (again)
  x86/kernel: remove tboot 1:1 page table creation code
  x86, efi: 1:1 pagetable mapping for virtual EFI calls
  x86, mm: Include the entire kernel memory map in trampoline_pgd
  ...

Merge tag 'for-3.8' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

2012-12-13T20:14:47+00:00

Pull PCI update from Bjorn Helgaas:
 "Host bridge hotplug:
   - Untangle _PRT from struct pci_bus (Bjorn Helgaas)
   - Request _OSC control before scanning root bus (Taku Izumi)
   - Assign resources when adding host bridge (Yinghai Lu)
   - Remove root bus when removing host bridge (Yinghai Lu)
   - Remove _PRT during hot remove (Yinghai Lu)

  SRIOV
    - Add sysfs knobs to control numVFs (Don Dutile)

  Power management
   - Notify devices when power resource turned on (Huang Ying)

  Bug fixes
   - Work around broken _SEG on HP xw9300 (Bjorn Helgaas)
   - Keep runtime PM enabled for unbound PCI devices (Huang Ying)
   - Fix Optimus dual-GPU runtime D3 suspend issue (Dave Airlie)
   - Fix xen frontend shutdown issue (David Vrabel)
   - Work around PLX PCI 9050 BAR alignment erratum (Ian Abbott)

  Miscellaneous
   - Add GPL license for drivers/pci/ioapic (Andrew Cooks)
   - Add standard PCI-X, PCIe ASPM register #defines (Bjorn Helgaas)
   - NumaChip remote PCI support (Daniel Blueman)
   - Fix PCIe Link Capabilities Supported Link Speed definition (Jingoo
     Han)
   - Convert dev_printk() to dev_info(), etc (Joe Perches)
   - Add support for non PCI BAR ROM data (Matthew Garrett)
   - Add x86 support for host bridge translation offset (Mike Yoknis)
   - Report success only when every driver supports AER (Vijay
     Pandarathil)"

Fix up trivial conflicts.

* tag 'for-3.8' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (48 commits)
  PCI: Use phys_addr_t for physical ROM address
  x86/PCI: Add NumaChip remote PCI support
  ath9k: Use standard #defines for PCIe Capability ASPM fields
  iwlwifi: Use standard #defines for PCIe Capability ASPM fields
  iwlwifi: collapse wrapper for pcie_capability_read_word()
  iwlegacy: Use standard #defines for PCIe Capability ASPM fields
  iwlegacy: collapse wrapper for pcie_capability_read_word()
  cxgb3: Use standard #defines for PCIe Capability ASPM fields
  PCI: Add standard PCIe Capability Link ASPM field names
  PCI/portdrv: Use PCI Express Capability accessors
  PCI: Use standard PCIe Capability Link register field names
  x86: Use PCI setup data
  PCI: Add support for non-BAR ROMs
  PCI: Add pcibios_add_device
  EFI: Stash ROMs if they're not in the PCI BAR
  PCI: Add and use standard PCI-X Capability register names
  PCI/PM: Keep runtime PM enabled for unbound PCI devices
  xen-pcifront: Handle backend CLOSED without CLOSING
  PCI: SRIOV control and status via sysfs (documentation)
  PCI/AER: Report success only when every device has AER-aware driver
  ...

EFI: Stash ROMs if they're not in the PCI BAR

2012-12-05T21:33:26+00:00

EFI provides support for providing PCI ROMs via means other than the ROM
BAR. This support vanishes after we've exited boot services, so add support
for stashing copies of the ROMs in setup_data if they're not otherwise
available.

Signed-off-by: Matthew Garrett 
Signed-off-by: Bjorn Helgaas 
Tested-by: Seth Forshee

efi_pstore: Check remaining space with QueryVariableInfo() before writing data

2012-11-27T00:01:46+00:00

[Issue]

As discussed in a thread below, Running out of space in EFI isn't a well-tested scenario.
And we wouldn't expect all firmware to handle it gracefully.
http://marc.info/?l=linux-kernel&m=134305325801789&w=2

On the other hand, current efi_pstore doesn't check a remaining space of storage at writing time.
Therefore, efi_pstore may not work if it tries to write a large amount of data.

[Patch Description]

To avoid handling the situation above, this patch checks if there is a space enough to log with
QueryVariableInfo() before writing data.

Signed-off-by: Seiji Aguchi 
Acked-by: Mike Waychison 
Signed-off-by: Tony Luck

efivarfs: Use query_variable_info() to limit kmalloc()

2012-11-13T12:33:21+00:00

We don't want someone who can write EFI variables to be able to
allocate arbitrarily large amounts of memory, so cap it to something
sensible like the amount of free space for EFI variables.

Acked-by: Jeremy Kerr 
Cc: Matthew Garrett 
Cc: Alan Cox 
Signed-off-by: Matt Fleming

x86-64/efi: Use EFI to deal with platform wall clock (again)

2012-10-30T10:39:20+00:00

Other than ix86, x86-64 on EFI so far didn't set the
{g,s}et_wallclock accessors to the EFI routines, thus
incorrectly using raw RTC accesses instead.

Simply removing the #ifdef around the respective code isn't
enough, however: While so far early get-time calls were done in
physical mode, this doesn't work properly for x86-64, as virtual
addresses would still need to be set up for all runtime regions
(which wasn't the case on the system I have access to), so
instead the patch moves the call to efi_enter_virtual_mode()
ahead (which in turn allows to drop all code related to calling
efi-get-time in physical mode).

Additionally the earlier calling of efi_set_executable()
requires the CPA code to cope, i.e. during early boot it must be
avoided to call cpa_flush_array(), as the first thing this
function does is a BUG_ON(irqs_disabled()).

Also make the two EFI functions in question here static -
they're not being referenced elsewhere.

History:

    This commit was originally merged as bacef661acdb ("x86-64/efi:
    Use EFI to deal with platform wall clock") but it resulted in some
    ASUS machines no longer booting due to a firmware bug, and so was
    reverted in f026cfa82f62. A pre-emptive fix for the buggy ASUS
    firmware was merged in 03a1c254975e ("x86, efi: 1:1 pagetable
    mapping for virtual EFI calls") so now this patch can be
    reapplied.

Signed-off-by: Jan Beulich 
Tested-by: Matt Fleming 
Acked-by: Matthew Garrett 
Cc: Ingo Molnar 
Cc: Peter Zijlstra 
Cc: H. Peter Anvin 
Signed-off-by: Matt Fleming  [added commit history]

efi: add efivars kobject to efi sysfs folder

2012-10-30T10:39:18+00:00

UEFI variable filesystem need a new mount point, so this patch add
efivars kobject to efi_kobj for create a /sys/firmware/efi/efivars
folder.

Cc: Matthew Garrett 
Cc: H. Peter Anvin 
Signed-off-by: Lee, Chun-Yi 
Signed-off-by: Jeremy Kerr 
Signed-off-by: Matt Fleming

efi: Add support for a UEFI variable filesystem

2012-10-30T10:39:16+00:00

The existing EFI variables code only supports variables of up to 1024
bytes. This limitation existed in version 0.99 of the EFI specification,
but was removed before any full releases. Since variables can now be
larger than a single page, sysfs isn't the best interface for this. So,
instead, let's add a filesystem. Variables can be read, written and
created, with the first 4 bytes of each variable representing its UEFI
attributes. The create() method doesn't actually commit to flash since
zero-length variables can't exist per-spec.

Updates from Jeremy Kerr .

Signed-off-by: Matthew Garrett 
Signed-off-by: Jeremy Kerr 
Signed-off-by: Matt Fleming