* 'timers-rtc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: Serialize EFI time accesses on rtc_lock
x86: Serialize SMP bootup CMOS accesses on rtc_lock
rtc: stmp3xxx: Remove UIE handlers
rtc: stmp3xxx: Get rid of mach-specific accessors
rtc: stmp3xxx: Initialize drvdata before registering device
rtc: stmp3xxx: Port stmp-functions to mxs-equivalents
rtc: stmp3xxx: Restore register definitions
rtc: vt8500: Use define instead of hardcoded value for status bit
The EFI specification requires that callers of the time related
runtime functions serialize with other CMOS accesses in the
kernel, as the EFI time functions may choose to also use the
legacy CMOS RTC.
Besides fixing a latent bug, this is a prerequisite to safely
enable the rtc-efi driver for x86, which ought to be preferred
over rtc-cmos on all EFI platforms.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Acked-by: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: <mjg@redhat.com>
Link: http://lkml.kernel.org/r/4E257E33020000780004E319@nat28.tlf.novell.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Matthew Garrett <mjg@redhat.com>
Testing suggests that at least some Lenovos and some Intels will
fail to reboot via EFI, attempting to jump to an unmapped
physical address. In the long run we could handle this by
providing a page table with a 1:1 mapping of physical addresses,
but for now it's probably just easier to assume that ACPI or
legacy methods will be present and reboot via those.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alan Cox <alan@linux.intel.com>
Link: http://lkml.kernel.org/r/1309985557-15350-1-git-send-email-mjg@redhat.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Consumers of the table pointers in struct efi check for
EFI_INVALID_TABLE_ADDR to determine validity, hence these
pointers should all be pre-initialized to this value (rather
than zero).
Noticed by the discrepancy between efivars' systab sysfs entry
showing all tables (and their pointers) despite the code
intending to only display the valid ones. No other bad effects
known, but having the various table parsing routines bogusly
access physical address zero is certainly not very desirable
(even though they're unlikely to find anything useful there).
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Link: http://lkml.kernel.org/r/4E13100A020000780004C256@nat28.tlf.novell.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Commit 916f676f8d started reserving boot service code since some systems
require you to keep that code around until SetVirtualAddressMap is called.
However, in some cases those areas will overlap with reserved regions.
The proper medium-term fix is to fix the bootloader to prevent the
conflicts from occurring by moving the kernel to a better position,
but the kernel should check for this possibility, and only reserve regions
which can be reserved.
Signed-off-by: Maarten Lankhorst <m.b.lankhorst@gmail.com>
Link: http://lkml.kernel.org/r/4DF7A005.1050407@gmail.com
Acked-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
We're currently missing support for any of the runtime service calls
introduced with the UEFI 2.0 spec in 2006. Add the infrastructure for
supporting them.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Link: http://lkml.kernel.org/r/1307388985-7852-2-git-send-email-mjg@redhat.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
UEFI stands for "Unified Extensible Firmware Interface", where "Firmware"
is an ancient African word meaning "Why do something right when you can
do it so wrong that children will weep and brave adults will cower before
you", and "UEI" is Celtic for "We missed DOS so we burned it into your
ROMs". The UEFI specification provides for runtime services (ie, another
way for the operating system to be forced to depend on the firmware) and
we rely on these for certain trivial tasks such as setting up the
bootloader. But some hardware fails to work if we attempt to use these
runtime services from physical mode, and so we have to switch into virtual
mode. So far so dreadful.
The specification makes it clear that the operating system is free to do
whatever it wants with boot services code after ExitBootServices() has been
called. SetVirtualAddressMap() can't be called until ExitBootServices() has
been. So, obviously, a whole bunch of EFI implementations call into boot
services code when we do that. Since we've been charmingly naive and
trusted that the specification may be somehow relevant to the real world,
we've already stuffed a picture of a penguin or something in that address
space. And just to make things more entertaining, we've also marked it
non-executable.
This patch allocates the boot services regions during EFI init and makes
sure that they're executable. Then, after SetVirtualAddressMap(), it
discards them and everyone lives happily ever after. Except for the ones
who have to work on EFI, who live sad lives haunted by the knowledge that
someone's eventually going to write yet another firmware specification.
[ hpa: adding this to urgent with a stable tag since it fixes currently-broken
hardware. However, I do not know what the dependencies are and so I do
not know which -stable versions this may be a candidate for. ]
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Link: http://lkml.kernel.org/r/1306331593-28715-1-git-send-email-mjg@redhat.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: <stable@kernel.org>
It's possible for init_memory_mapping() to fail to map the entire region
if it crosses a boundary, so ensure that we complete the mapping.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Link: http://lkml.kernel.org/r/1304623186-18261-5-git-send-email-mjg@redhat.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Experimentation with various EFI implementations has shown that functions
outside runtime services will still update their pointers if
SetVirtualAddressMap() is called with memory descriptors outside the
runtime area. This is obviously insane, and therefore is unsurprising.
Evidence from instrumenting another EFI implementation suggests that it
only passes the set of descriptors covering runtime regions, so let's
avoid any problems by doing the same. Runtime descriptors are copied to
a separate memory map, and only that map is passed back to the firmware.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Link: http://lkml.kernel.org/r/1304623186-18261-4-git-send-email-mjg@redhat.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Some firmware implementations assume that physically contiguous regions
will be contiguous in virtual address space. This assumption is, obviously,
entirely unjustifiable. Said firmware implementations lack the good grace
to handle their failings in a measured and reasonable manner, instead
tending to shit all over address space and oopsing the kernel.
In an ideal universe these firmware implementations would simultaneously
catch fire and cease to be a problem, but since some of them are present
in attractively thin and shiny metal devices vanity wins out and some
poor developer spends an extended period of time surrounded by a
growing array of empty bottles until the underlying reason becomes
apparent. Said developer presents this patch, which simply merges
adjacent regions if they happen to be contiguous and have the same EFI
memory type and caching attributes.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Link: http://lkml.kernel.org/r/1304623186-18261-3-git-send-email-mjg@redhat.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
The core EFI code and 64-bit EFI code currently have independent
implementations of code for setting memory regions as executable or not.
Let's consolidate them.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Link: http://lkml.kernel.org/r/1304623186-18261-2-git-send-email-mjg@redhat.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
The spec says that SetVirtualAddressMap doesn't work once you're in
virtual mode, so there's no point in having infrastructure for calling
it from there.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Link: http://lkml.kernel.org/r/1304623186-18261-1-git-send-email-mjg@redhat.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
