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 <airlied@linux.ie>
Cc: Corentin Chary <corentincj@iksaif.net>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Olof Johansson <olof@lixom.net>
Cc: Peter Jones <pjones@redhat.com>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Steve Langasek <steve.langasek@canonical.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Konrad Rzeszutek Wilk <konrad@kernel.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: <stable@vger.kernel.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

This provides unified readq()/writeq() helper functions for 32-bit
drivers.

For some cases, readq/writeq without atomicity is harmful, and order of
io access has to be specified explicitly.  So in this patch, new two
header files which contain non-atomic readq/writeq are added.

 - <asm-generic/io-64-nonatomic-lo-hi.h> provides non-atomic readq/
   writeq with the order of lower address -> higher address

 - <asm-generic/io-64-nonatomic-hi-lo.h> provides non-atomic readq/
   writeq with reversed order

This allows us to remove some readq()s that were added drivers when the
default non-atomic ones were removed in commit dbee8a0a ("x86:
remove 32-bit versions of readq()/writeq()")

The drivers which need readq/writeq but can do with the non-atomic ones
must add the line:

  #include <asm-generic/io-64-nonatomic-lo-hi.h> /* or hi-lo.h */

But this will be nop in 64-bit environments, and no other #ifdefs are
required.  So I believe that this patch can solve the problem of
 1. driver-specific readq/writeq
 2. atomicity and order of io access

This patch is tested with building allyesconfig and allmodconfig as
ARCH=x86 and ARCH=i386 on top of tip/master.

Cc: Kashyap Desai <Kashyap.Desai@lsi.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Ravi Anand <ravi.anand@qlogic.com>
Cc: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Jason Uhlenkott <juhlenko@akamai.com>
Cc: James Bottomley <James.Bottomley@parallels.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Roland Dreier <roland@purestorage.com>
Cc: James Bottomley <jbottomley@parallels.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NHitoshi Mitake <h.mitake@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

After all sysdev classes are ported to regular driver core entities, the
sysdev implementation will be entirely removed from the kernel.

Cc: Matthew Garrett <mjg@redhat.com>
Signed-off-by: NKay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Remove hard coded prefixes from logging messages.
Neaten RTL_DEBUG macro and uses.
Convert __FUNCTION__ to __func__.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

Just print them as %p.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

The presense of a writeq() implementation on 32-bit x86 that splits the
64-bit write into two 32-bit writes turns out to break the mpt2sas driver
(and in general is risky for drivers as was discussed in
<http://lkml.kernel.org/r/adaab6c1h7c.fsf@cisco.com>).  To fix this,
revert 2c5643b1 ("x86: provide readq()/writeq() on 32-bit too") and
follow-on cleanups.

This unfortunately leads to pushing non-atomic definitions of readq() and
write() to various x86-only drivers that in the meantime started using the
definitions in the x86 version of <asm/io.h>.  However as discussed
exhaustively, this is actually the right thing to do, because the right
way to split a 64-bit transaction is hardware dependent and therefore
belongs in the hardware driver (eg mpt2sas needs a spinlock to make sure
no other accesses occur in between the two halves of the access).

Build tested on 32- and 64-bit x86 allmodconfig.

Link: http://lkml.kernel.org/r/x86-32-writeq-is-broken@mdm.bga.comAcked-by: NHitoshi Mitake <h.mitake@gmail.com>
Cc: Kashyap Desai <Kashyap.Desai@lsi.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Ravi Anand <ravi.anand@qlogic.com>
Cc: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Jason Uhlenkott <juhlenko@akamai.com>
Acked-by: NJames Bottomley <James.Bottomley@parallels.com>
Acked-by: NIngo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Some of the IBM servers that are supported by ibm_rtl
can run in both Legacy mode (BIOS) and in UEFI mode.
When running in UEFI mode, it is possible that the
EBDA table exists but cannot be mapped and reports
errors.  We need to make sure that by default we don't
try to probe the machines if they are running in UEFI
mode.
Signed-off-by: NVernon Mauery <vernux@us.ibm.com>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

Allow all IBM machines to pass the DMI check so that we
don't have to add them one by one to the driver.  Any IBM
machine that has the _RTL_ table in the EBDA will work.
Signed-off-by: NVernon Mauery <vernux@us.ibm.com>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

Fix printk format warning:

drivers/platform/x86/ibm_rtl.c:305:warning: format '%#llx' expects type 'long long unsigned int', but argument 2 has type 'phys_addr_t'
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Cc: Keith Mannthey <kmannth@us.ibm.com>
Cc: Vernon Mauery <vernux@us.ibm.com>
Cc: platform-driver-x86@vger.kernel.org
Cc: Matthew Garrett <mjg@redhat.com>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

After a period of RFC for this driver, I think it is ready
for inclusion in the platform-driver-x86 tree, hopefully to
be staged in the next merge window into Linus's tree.

--Vernon

------------------------------------------------------------

IBM Real-Time "SMI Free" mode driver

This driver supports the Real-Time Linux (RTL) BIOS feature.
The RTL feature allows non-fatal System Management Interrupts
(SMIs) to be disabled on supported IBM platforms and is
intended to be coupled with a user-space daemon to monitor
the hardware in a way that can be prioritized and scheduled
to better suit the requirements for the system.

The Device is presented as a special "_RTL_" table to the OS
in the Extended BIOS Data Area.  There is a simple protocol
for entering and exiting the mode at runtime.  This driver
creates a simple sysfs interface to allow a simple entry and
exit from RTL mode in the UFI/BIOS.

Since the driver is specific to IBM SystemX hardware (x86-
based servers) it only builds on x86 builds.  To reduce the
risk of loading on the wrong hardware, the module uses DMI
information and checks a list of servers that are known to
work.
Signed-off-by: NVernon Mauery <vernux@us.ibm.com>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>