<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/drivers, branch v3.8-rc6</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>Merge tag 'dm-3.8-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm</title>
<updated>2013-02-01T01:04:22+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2013-02-01T01:04:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=cc6c954a076c5df7e0ac8d5e4ffa8b4f5572ae1d'/>
<id>cc6c954a076c5df7e0ac8d5e4ffa8b4f5572ae1d</id>
<content type='text'>
Pull more device-mapper fixes from Alasdair G Kergon:
 "A fix for stacked dm thin devices and a fix for the new dm WRITE SAME
  support."

* tag 'dm-3.8-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm:
  dm: fix write same requests counting
  dm thin: fix queue limits stacking
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull more device-mapper fixes from Alasdair G Kergon:
 "A fix for stacked dm thin devices and a fix for the new dm WRITE SAME
  support."

* tag 'dm-3.8-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm:
  dm: fix write same requests counting
  dm thin: fix queue limits stacking
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'for-3.8/upstream-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid</title>
<updated>2013-01-31T21:44:59+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2013-01-31T21:44:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=cf5425bfcd6909f9831a00bc06ccb9a5b163766a'/>
<id>cf5425bfcd6909f9831a00bc06ccb9a5b163766a</id>
<content type='text'>
PullHID fixes from Jiri Kosina:

 - fix i2c-hid and hidraw interaction, by Benjamin Tissoires

 - a quirk to make a particular device (Formosa IR receiver) work
   properly, by Nicholas Santos

* 'for-3.8/upstream-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
  HID: i2c-hid: fix i2c_hid_output_raw_report
  HID: usbhid: quirk for Formosa IR receiver
  HID: remove x bit from sensor doc
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
PullHID fixes from Jiri Kosina:

 - fix i2c-hid and hidraw interaction, by Benjamin Tissoires

 - a quirk to make a particular device (Formosa IR receiver) work
   properly, by Nicholas Santos

* 'for-3.8/upstream-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
  HID: i2c-hid: fix i2c_hid_output_raw_report
  HID: usbhid: quirk for Formosa IR receiver
  HID: remove x bit from sensor doc
</pre>
</div>
</content>
</entry>
<entry>
<title>HID: i2c-hid: fix i2c_hid_output_raw_report</title>
<updated>2013-01-31T16:57:53+00:00</updated>
<author>
<name>Benjamin Tissoires</name>
<email>benjamin.tissoires@gmail.com</email>
</author>
<published>2013-01-31T16:50:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=c284979affcc6870a9a6545fc4b1adb3816dfcbf'/>
<id>c284979affcc6870a9a6545fc4b1adb3816dfcbf</id>
<content type='text'>
i2c_hid_output_raw_report is used by hidraw to forward set_report requests.
The current implementation of i2c_hid_set_report needs to take the
report_id as an argument. The report_id is stored in the first byte
of the buffer in argument of i2c_hid_output_raw_report.

Not removing the report_id from the given buffer adds this byte 2 times
in the command, leading to a non working command.

Reported-by: Andrew Duggan &lt;aduggan@synaptics.com&gt;
Signed-off-by: Benjamin Tissoires &lt;benjamin.tissoires@gmail.com&gt;
Signed-off-by: Jiri Kosina &lt;jkosina@suse.cz&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
i2c_hid_output_raw_report is used by hidraw to forward set_report requests.
The current implementation of i2c_hid_set_report needs to take the
report_id as an argument. The report_id is stored in the first byte
of the buffer in argument of i2c_hid_output_raw_report.

Not removing the report_id from the given buffer adds this byte 2 times
in the command, leading to a non working command.

Reported-by: Andrew Duggan &lt;aduggan@synaptics.com&gt;
Signed-off-by: Benjamin Tissoires &lt;benjamin.tissoires@gmail.com&gt;
Signed-off-by: Jiri Kosina &lt;jkosina@suse.cz&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dm: fix write same requests counting</title>
<updated>2013-01-31T14:23:36+00:00</updated>
<author>
<name>Alasdair G Kergon</name>
<email>agk@redhat.com</email>
</author>
<published>2013-01-31T14:23:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=fe7af2d3babefabd96a39e8b0d58ede88f3c7993'/>
<id>fe7af2d3babefabd96a39e8b0d58ede88f3c7993</id>
<content type='text'>
When processing write same requests, fix dm to send the configured
number of WRITE SAME requests to the target rather than the number of
discards, which is not always the same.

Device-mapper WRITE SAME support was introduced by commit
23508a96cd2e857d57044a2ed7d305f2d9daf441 ("dm: add WRITE SAME support").

Signed-off-by: Alasdair G Kergon &lt;agk@redhat.com&gt;
Acked-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When processing write same requests, fix dm to send the configured
number of WRITE SAME requests to the target rather than the number of
discards, which is not always the same.

Device-mapper WRITE SAME support was introduced by commit
23508a96cd2e857d57044a2ed7d305f2d9daf441 ("dm: add WRITE SAME support").

Signed-off-by: Alasdair G Kergon &lt;agk@redhat.com&gt;
Acked-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dm thin: fix queue limits stacking</title>
<updated>2013-01-31T14:11:14+00:00</updated>
<author>
<name>Mike Snitzer</name>
<email>snitzer@redhat.com</email>
</author>
<published>2013-01-31T14:11:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=0f640dca08330dfc7820d610578e5935b5e654b2'/>
<id>0f640dca08330dfc7820d610578e5935b5e654b2</id>
<content type='text'>
thin_io_hints() is blindly copying the queue limits from the thin-pool
which can lead to incorrect limits being set.  The fix here simply
deletes the thin_io_hints() hook which leaves the existing stacking
infrastructure to set the limits correctly.

When a thin-pool uses an MD device for the data device a thin device
from the thin-pool must respect MD's constraints about disallowing a bio
from spanning multiple chunks.  Otherwise we can see problems.  If the raid0
chunksize is 1152K and thin-pool chunksize is 256K I see the following
md/raid0 error (with extra debug tracing added to thin_endio) when
mkfs.xfs is executed against the thin device:

md/raid0:md99: make_request bug: can't convert block across chunks or bigger than 1152k 6688 127
device-mapper: thin: bio sector=2080 err=-5 bi_size=130560 bi_rw=17 bi_vcnt=32 bi_idx=0

This extra DM debugging shows that the failing bio is spanning across
the first and second logical 1152K chunk (sector 2080 + 255 takes the
bio beyond the first chunk's boundary of sector 2304).  So the bio
splitting that DM is doing clearly isn't respecting the MD limits.

max_hw_sectors_kb is 127 for both the thin-pool and thin device
(queue_max_hw_sectors returns 255 so we'll excuse sysfs's lack of
precision).  So this explains why bi_size is 130560.

But the thin device's max_hw_sectors_kb should be 4 (PAGE_SIZE) given
that it doesn't have a .merge function (for bio_add_page to consult
indirectly via dm_merge_bvec) yet the thin-pool does sit above an MD
device that has a compulsory merge_bvec_fn.  This scenario is exactly
why DM must resort to sending single PAGE_SIZE bios to the underlying
layer. Some additional context for this is available in the header for
commit 8cbeb67a ("dm: avoid unsupported spanning of md stripe boundaries").

Long story short, the reason a thin device doesn't properly get
configured to have a max_hw_sectors_kb of 4 (PAGE_SIZE) is that
thin_io_hints() is blindly copying the queue limits from the thin-pool
device directly to the thin device's queue limits.

Fix this by eliminating thin_io_hints.  Doing so is safe because the
block layer's queue limits stacking already enables the upper level thin
device to inherit the thin-pool device's discard and minimum_io_size and
optimal_io_size limits that get set in pool_io_hints.  But avoiding the
queue limits copy allows the thin and thin-pool limits to be different
where it is important, namely max_hw_sectors_kb.

Reported-by: Daniel Browning &lt;db@kavod.com&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Alasdair G Kergon &lt;agk@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
thin_io_hints() is blindly copying the queue limits from the thin-pool
which can lead to incorrect limits being set.  The fix here simply
deletes the thin_io_hints() hook which leaves the existing stacking
infrastructure to set the limits correctly.

When a thin-pool uses an MD device for the data device a thin device
from the thin-pool must respect MD's constraints about disallowing a bio
from spanning multiple chunks.  Otherwise we can see problems.  If the raid0
chunksize is 1152K and thin-pool chunksize is 256K I see the following
md/raid0 error (with extra debug tracing added to thin_endio) when
mkfs.xfs is executed against the thin device:

md/raid0:md99: make_request bug: can't convert block across chunks or bigger than 1152k 6688 127
device-mapper: thin: bio sector=2080 err=-5 bi_size=130560 bi_rw=17 bi_vcnt=32 bi_idx=0

This extra DM debugging shows that the failing bio is spanning across
the first and second logical 1152K chunk (sector 2080 + 255 takes the
bio beyond the first chunk's boundary of sector 2304).  So the bio
splitting that DM is doing clearly isn't respecting the MD limits.

max_hw_sectors_kb is 127 for both the thin-pool and thin device
(queue_max_hw_sectors returns 255 so we'll excuse sysfs's lack of
precision).  So this explains why bi_size is 130560.

But the thin device's max_hw_sectors_kb should be 4 (PAGE_SIZE) given
that it doesn't have a .merge function (for bio_add_page to consult
indirectly via dm_merge_bvec) yet the thin-pool does sit above an MD
device that has a compulsory merge_bvec_fn.  This scenario is exactly
why DM must resort to sending single PAGE_SIZE bios to the underlying
layer. Some additional context for this is available in the header for
commit 8cbeb67a ("dm: avoid unsupported spanning of md stripe boundaries").

Long story short, the reason a thin device doesn't properly get
configured to have a max_hw_sectors_kb of 4 (PAGE_SIZE) is that
thin_io_hints() is blindly copying the queue limits from the thin-pool
device directly to the thin device's queue limits.

Fix this by eliminating thin_io_hints.  Doing so is safe because the
block layer's queue limits stacking already enables the upper level thin
device to inherit the thin-pool device's discard and minimum_io_size and
optimal_io_size limits that get set in pool_io_hints.  But avoiding the
queue limits copy allows the thin and thin-pool limits to be different
where it is important, namely max_hw_sectors_kb.

Reported-by: Daniel Browning &lt;db@kavod.com&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Alasdair G Kergon &lt;agk@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2013-01-31T06:10:36+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2013-01-31T06:10:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=04c2eee5b9dfcb13f3cd07a5537fb8c785f2751a'/>
<id>04c2eee5b9dfcb13f3cd07a5537fb8c785f2751a</id>
<content type='text'>
Pull x86 EFI fixes from Peter Anvin:
 "This is a collection of fixes for the EFI support.  The controversial
  bit here is a set of patches which bumps the boot protocol version as
  part of fixing some serious problems with the EFI handover protocol,
  used when booting under EFI using a bootloader as opposed to directly
  from EFI.  These changes should also make it a lot saner to support
  cross-mode 32/64-bit EFI booting in the future.  Getting these changes
  into 3.8 means we avoid presenting an inconsistent ABI to bootloaders.

  Other changes are display detection and fixing efivarfs."

* 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, efi: remove attribute check from setup_efi_pci
  x86, build: Dynamically find entry points in compressed startup code
  x86, efi: Fix PCI ROM handing in EFI boot stub, in 32-bit mode
  x86, efi: Fix 32-bit EFI handover protocol entry point
  x86, efi: Fix display detection in EFI boot stub
  x86, boot: Define the 2.12 bzImage boot protocol
  x86/boot: Fix minor fd leakage in tools/relocs.c
  x86, efi: Set runtime_version to the EFI spec revision
  x86, efi: fix 32-bit warnings in setup_efi_pci()
  efivarfs: Delete dentry from dcache in efivarfs_file_write()
  efivarfs: Never return ENOENT from firmware
  efi, x86: Pass a proper identity mapping in efi_call_phys_prelog
  efivarfs: Drop link count of the right inode
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull x86 EFI fixes from Peter Anvin:
 "This is a collection of fixes for the EFI support.  The controversial
  bit here is a set of patches which bumps the boot protocol version as
  part of fixing some serious problems with the EFI handover protocol,
  used when booting under EFI using a bootloader as opposed to directly
  from EFI.  These changes should also make it a lot saner to support
  cross-mode 32/64-bit EFI booting in the future.  Getting these changes
  into 3.8 means we avoid presenting an inconsistent ABI to bootloaders.

  Other changes are display detection and fixing efivarfs."

* 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, efi: remove attribute check from setup_efi_pci
  x86, build: Dynamically find entry points in compressed startup code
  x86, efi: Fix PCI ROM handing in EFI boot stub, in 32-bit mode
  x86, efi: Fix 32-bit EFI handover protocol entry point
  x86, efi: Fix display detection in EFI boot stub
  x86, boot: Define the 2.12 bzImage boot protocol
  x86/boot: Fix minor fd leakage in tools/relocs.c
  x86, efi: Set runtime_version to the EFI spec revision
  x86, efi: fix 32-bit warnings in setup_efi_pci()
  efivarfs: Delete dentry from dcache in efivarfs_file_write()
  efivarfs: Never return ENOENT from firmware
  efi, x86: Pass a proper identity mapping in efi_call_phys_prelog
  efivarfs: Drop link count of the right inode
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2013-01-31T06:08:43+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2013-01-31T06:08:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=bdb0ae6a767ef2622eb282e06fc225e855341653'/>
<id>bdb0ae6a767ef2622eb282e06fc225e855341653</id>
<content type='text'>
Pull x86 fixes from Peter Anvin:
 "This is a collection of miscellaneous fixes, the most important one is
  the fix for the Samsung laptop bricking issue (auto-blacklisting the
  samsung-laptop driver); the efi_enabled() changes you see below are
  prerequisites for that fix.

  The other issues fixed are booting on OLPC XO-1.5, an UV fix, NMI
  debugging, and requiring CAP_SYS_RAWIO for MSR references, just as
  with I/O port references."

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  samsung-laptop: Disable on EFI hardware
  efi: Make 'efi_enabled' a function to query EFI facilities
  smp: Fix SMP function call empty cpu mask race
  x86/msr: Add capabilities check
  x86/dma-debug: Bump PREALLOC_DMA_DEBUG_ENTRIES
  x86/olpc: Fix olpc-xo1-sci.c build errors
  arch/x86/platform/uv: Fix incorrect tlb flush all issue
  x86-64: Fix unwind annotations in recent NMI changes
  x86-32: Start out cr0 clean, disable paging before modifying cr3/4
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull x86 fixes from Peter Anvin:
 "This is a collection of miscellaneous fixes, the most important one is
  the fix for the Samsung laptop bricking issue (auto-blacklisting the
  samsung-laptop driver); the efi_enabled() changes you see below are
  prerequisites for that fix.

  The other issues fixed are booting on OLPC XO-1.5, an UV fix, NMI
  debugging, and requiring CAP_SYS_RAWIO for MSR references, just as
  with I/O port references."

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  samsung-laptop: Disable on EFI hardware
  efi: Make 'efi_enabled' a function to query EFI facilities
  smp: Fix SMP function call empty cpu mask race
  x86/msr: Add capabilities check
  x86/dma-debug: Bump PREALLOC_DMA_DEBUG_ENTRIES
  x86/olpc: Fix olpc-xo1-sci.c build errors
  arch/x86/platform/uv: Fix incorrect tlb flush all issue
  x86-64: Fix unwind annotations in recent NMI changes
  x86-32: Start out cr0 clean, disable paging before modifying cr3/4
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'efi-for-3.8' into x86/efi</title>
<updated>2013-01-30T22:43:05+00:00</updated>
<author>
<name>H. Peter Anvin</name>
<email>hpa@linux.intel.com</email>
</author>
<published>2013-01-30T22:43:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=becbd6608026c15afd88fd3d0c893dfb7b8c7845'/>
<id>becbd6608026c15afd88fd3d0c893dfb7b8c7845</id>
<content type='text'>
Various urgent EFI fixes and some warning cleanups for v3.8

  * EFI boot stub fix for Macbook Pro's from Maarten Lankhorst
  * Fix an oops in efivarfs from Lingzhu Xiang
  * 32-bit warning cleanups from Jan Beulich
  * Patch to Boot on &gt;512GB RAM systems from Nathan Zimmer
  * Set efi.runtime_version correctly
  * efivarfs updates

Signed-off-by: H. Peter Anvin &lt;hpa@linux.intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Various urgent EFI fixes and some warning cleanups for v3.8

  * EFI boot stub fix for Macbook Pro's from Maarten Lankhorst
  * Fix an oops in efivarfs from Lingzhu Xiang
  * 32-bit warning cleanups from Jan Beulich
  * Patch to Boot on &gt;512GB RAM systems from Nathan Zimmer
  * Set efi.runtime_version correctly
  * efivarfs updates

Signed-off-by: H. Peter Anvin &lt;hpa@linux.intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>samsung-laptop: Disable on EFI hardware</title>
<updated>2013-01-30T19:52:11+00:00</updated>
<author>
<name>Matt Fleming</name>
<email>matt.fleming@intel.com</email>
</author>
<published>2013-01-03T09:02:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=e0094244e41c4d0c7ad69920681972fc45d8ce34'/>
<id>e0094244e41c4d0c7ad69920681972fc45d8ce34</id>
<content type='text'>
It has been reported that running this driver on some Samsung laptops
with EFI can cause those machines to become bricked as detailed in the
following report,

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

There have also been reports of this driver causing Machine Check
Exceptions on recent EFI-enabled Samsung laptops,

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

So disable it if booting from EFI since this driver relies on
grovelling around in the BIOS memory map which isn't going to work.

Cc: Corentin Chary &lt;corentincj@iksaif.net&gt;
Cc: Matthew Garrett &lt;mjg59@srcf.ucam.org&gt;
Cc: Colin Ian King &lt;colin.king@canonical.com&gt;
Cc: Steve Langasek &lt;steve.langasek@canonical.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Matt Fleming &lt;matt.fleming@intel.com&gt;
Signed-off-by: H. Peter Anvin &lt;hpa@linux.intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
It has been reported that running this driver on some Samsung laptops
with EFI can cause those machines to become bricked as detailed in the
following report,

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

There have also been reports of this driver causing Machine Check
Exceptions on recent EFI-enabled Samsung laptops,

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

So disable it if booting from EFI since this driver relies on
grovelling around in the BIOS memory map which isn't going to work.

Cc: Corentin Chary &lt;corentincj@iksaif.net&gt;
Cc: Matthew Garrett &lt;mjg59@srcf.ucam.org&gt;
Cc: Colin Ian King &lt;colin.king@canonical.com&gt;
Cc: Steve Langasek &lt;steve.langasek@canonical.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Matt Fleming &lt;matt.fleming@intel.com&gt;
Signed-off-by: H. Peter Anvin &lt;hpa@linux.intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>efi: Make 'efi_enabled' a function to query EFI facilities</title>
<updated>2013-01-30T19:51:59+00:00</updated>
<author>
<name>Matt Fleming</name>
<email>matt.fleming@intel.com</email>
</author>
<published>2012-11-14T09:42:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=83e68189745ad931c2afd45d8ee3303929233e7f'/>
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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 &lt;airlied@linux.ie&gt;
Cc: Corentin Chary &lt;corentincj@iksaif.net&gt;
Cc: Matthew Garrett &lt;mjg59@srcf.ucam.org&gt;
Cc: Dave Jiang &lt;dave.jiang@intel.com&gt;
Cc: Olof Johansson &lt;olof@lixom.net&gt;
Cc: Peter Jones &lt;pjones@redhat.com&gt;
Cc: Colin Ian King &lt;colin.king@canonical.com&gt;
Cc: Steve Langasek &lt;steve.langasek@canonical.com&gt;
Cc: Tony Luck &lt;tony.luck@intel.com&gt;
Cc: Konrad Rzeszutek Wilk &lt;konrad@kernel.org&gt;
Cc: Rafael J. Wysocki &lt;rjw@sisk.pl&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Matt Fleming &lt;matt.fleming@intel.com&gt;
Signed-off-by: H. Peter Anvin &lt;hpa@linux.intel.com&gt;
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<pre>
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 &lt;airlied@linux.ie&gt;
Cc: Corentin Chary &lt;corentincj@iksaif.net&gt;
Cc: Matthew Garrett &lt;mjg59@srcf.ucam.org&gt;
Cc: Dave Jiang &lt;dave.jiang@intel.com&gt;
Cc: Olof Johansson &lt;olof@lixom.net&gt;
Cc: Peter Jones &lt;pjones@redhat.com&gt;
Cc: Colin Ian King &lt;colin.king@canonical.com&gt;
Cc: Steve Langasek &lt;steve.langasek@canonical.com&gt;
Cc: Tony Luck &lt;tony.luck@intel.com&gt;
Cc: Konrad Rzeszutek Wilk &lt;konrad@kernel.org&gt;
Cc: Rafael J. Wysocki &lt;rjw@sisk.pl&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Matt Fleming &lt;matt.fleming@intel.com&gt;
Signed-off-by: H. Peter Anvin &lt;hpa@linux.intel.com&gt;
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