<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel.git/arch/x86/kernel/acpi, branch linux-4.19.y</title>
<subtitle>Hosts the 0x221E linux distro kernel.
</subtitle>
<id>https://git.0xinfinity.dev/distro/kernel.git/atom?h=linux-4.19.y</id>
<link rel='self' href='https://git.0xinfinity.dev/distro/kernel.git/atom?h=linux-4.19.y'/>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/'/>
<updated>2023-11-08T10:22:17Z</updated>
<entry>
<title>x86/i8259: Skip probing when ACPI/MADT advertises PCAT compatibility</title>
<updated>2023-11-08T10:22:17Z</updated>
<author>
<name>Thomas Gleixner</name>
</author>
<published>2023-10-25T21:04:15Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=c1a4390ec8ad5c56e8e3ab4613e8dc1d03e15eeb'/>
<id>urn:sha1:c1a4390ec8ad5c56e8e3ab4613e8dc1d03e15eeb</id>
<content type='text'>
commit 128b0c9781c9f2651bea163cb85e52a6c7be0f9e upstream.

David and a few others reported that on certain newer systems some legacy
interrupts fail to work correctly.

Debugging revealed that the BIOS of these systems leaves the legacy PIC in
uninitialized state which makes the PIC detection fail and the kernel
switches to a dummy implementation.

Unfortunately this fallback causes quite some code to fail as it depends on
checks for the number of legacy PIC interrupts or the availability of the
real PIC.

In theory there is no reason to use the PIC on any modern system when
IO/APIC is available, but the dependencies on the related checks cannot be
resolved trivially and on short notice. This needs lots of analysis and
rework.

The PIC detection has been added to avoid quirky checks and force selection
of the dummy implementation all over the place, especially in VM guest
scenarios. So it's not an option to revert the relevant commit as that
would break a lot of other scenarios.

One solution would be to try to initialize the PIC on detection fail and
retry the detection, but that puts the burden on everything which does not
have a PIC.

Fortunately the ACPI/MADT table header has a flag field, which advertises
in bit 0 that the system is PCAT compatible, which means it has a legacy
8259 PIC.

Evaluate that bit and if set avoid the detection routine and keep the real
PIC installed, which then gets initialized (for nothing) and makes the rest
of the code with all the dependencies work again.

Fixes: e179f6914152 ("x86, irq, pic: Probe for legacy PIC and set legacy_pic appropriately")
Reported-by: David Lazar &lt;dlazar@gmail.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Tested-by: David Lazar &lt;dlazar@gmail.com&gt;
Reviewed-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Reviewed-by: Mario Limonciello &lt;mario.limonciello@amd.com&gt;
Cc: stable@vger.kernel.org
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218003
Link: https://lore.kernel.org/r/875y2u5s8g.ffs@tglx
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>ACPI / x86: Work around broken XSDT on Advantech DAC-BJ01 board</title>
<updated>2022-03-28T06:41:44Z</updated>
<author>
<name>Mark Cilissen</name>
</author>
<published>2022-03-07T03:16:58Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=783d2ec3700d779311e6cc06620122328c6579e6'/>
<id>urn:sha1:783d2ec3700d779311e6cc06620122328c6579e6</id>
<content type='text'>
commit e702196bf85778f2c5527ca47f33ef2e2fca8297 upstream.

On this board the ACPI RSDP structure points to both a RSDT and an XSDT,
but the XSDT points to a truncated FADT. This causes all sorts of trouble
and usually a complete failure to boot after the following error occurs:

  ACPI Error: Unsupported address space: 0x20 (*/hwregs-*)
  ACPI Error: AE_SUPPORT, Unable to initialize fixed events (*/evevent-*)
  ACPI: Unable to start ACPI Interpreter

This leaves the ACPI implementation in such a broken state that subsequent
kernel subsystem initialisations go wrong, resulting in among others
mismapped PCI memory, SATA and USB enumeration failures, and freezes.

As this is an older embedded platform that will likely never see any BIOS
updates to address this issue and its default shipping OS only complies to
ACPI 1.0, work around this by forcing `acpi=rsdt`. This patch, applied on
top of Linux 5.10.102, was confirmed on real hardware to fix the issue.

Signed-off-by: Mark Cilissen &lt;mark@yotsuba.nl&gt;
Cc: All applicable &lt;stable@vger.kernel.org&gt;
Reviewed-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>ACPI: tables: x86: Reserve memory occupied by ACPI tables</title>
<updated>2021-05-07T08:49:25Z</updated>
<author>
<name>Rafael J. Wysocki</name>
</author>
<published>2021-03-23T19:26:52Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=7d329dd0a1b3302e10f0f25ef08538c7598d118f'/>
<id>urn:sha1:7d329dd0a1b3302e10f0f25ef08538c7598d118f</id>
<content type='text'>
commit 1a1c130ab7575498eed5bcf7220037ae09cd1f8a upstream.

The following problem has been reported by George Kennedy:

 Since commit 7fef431be9c9 ("mm/page_alloc: place pages to tail
 in __free_pages_core()") the following use after free occurs
 intermittently when ACPI tables are accessed.

 BUG: KASAN: use-after-free in ibft_init+0x134/0xc49
 Read of size 4 at addr ffff8880be453004 by task swapper/0/1
 CPU: 3 PID: 1 Comm: swapper/0 Not tainted 5.12.0-rc1-7a7fd0d #1
 Call Trace:
  dump_stack+0xf6/0x158
  print_address_description.constprop.9+0x41/0x60
  kasan_report.cold.14+0x7b/0xd4
  __asan_report_load_n_noabort+0xf/0x20
  ibft_init+0x134/0xc49
  do_one_initcall+0xc4/0x3e0
  kernel_init_freeable+0x5af/0x66b
  kernel_init+0x16/0x1d0
  ret_from_fork+0x22/0x30

 ACPI tables mapped via kmap() do not have their mapped pages
 reserved and the pages can be "stolen" by the buddy allocator.

Apparently, on the affected system, the ACPI table in question is
not located in "reserved" memory, like ACPI NVS or ACPI Data, that
will not be used by the buddy allocator, so the memory occupied by
that table has to be explicitly reserved to prevent the buddy
allocator from using it.

In order to address this problem, rearrange the initialization of the
ACPI tables on x86 to locate the initial tables earlier and reserve
the memory occupied by them.

The other architectures using ACPI should not be affected by this
change.

Link: https://lore.kernel.org/linux-acpi/1614802160-29362-1-git-send-email-george.kennedy@oracle.com/
Reported-by: George Kennedy &lt;george.kennedy@oracle.com&gt;
Tested-by: George Kennedy &lt;george.kennedy@oracle.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Mike Rapoport &lt;rppt@linux.ibm.com&gt;
Cc: 5.10+ &lt;stable@vger.kernel.org&gt; # 5.10+
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>x86: ACPI: fix CPU hotplug deadlock</title>
<updated>2020-04-23T08:30:20Z</updated>
<author>
<name>Qian Cai</name>
</author>
<published>2020-04-03T14:03:45Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=67e5b7090905050a8c5efbe14889695a1c6b77f6'/>
<id>urn:sha1:67e5b7090905050a8c5efbe14889695a1c6b77f6</id>
<content type='text'>
[ Upstream commit 696ac2e3bf267f5a2b2ed7d34e64131f2287d0ad ]

Similar to commit 0266d81e9bf5 ("acpi/processor: Prevent cpu hotplug
deadlock") except this is for acpi_processor_ffh_cstate_probe():

"The problem is that the work is scheduled on the current CPU from the
hotplug thread associated with that CPU.

It's not required to invoke these functions via the workqueue because
the hotplug thread runs on the target CPU already.

Check whether current is a per cpu thread pinned on the target CPU and
invoke the function directly to avoid the workqueue."

 WARNING: possible circular locking dependency detected
 ------------------------------------------------------
 cpuhp/1/15 is trying to acquire lock:
 ffffc90003447a28 ((work_completion)(&amp;wfc.work)){+.+.}-{0:0}, at: __flush_work+0x4c6/0x630

 but task is already holding lock:
 ffffffffafa1c0e8 (cpuidle_lock){+.+.}-{3:3}, at: cpuidle_pause_and_lock+0x17/0x20

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:

 -&gt; #1 (cpu_hotplug_lock){++++}-{0:0}:
 cpus_read_lock+0x3e/0xc0
 irq_calc_affinity_vectors+0x5f/0x91
 __pci_enable_msix_range+0x10f/0x9a0
 pci_alloc_irq_vectors_affinity+0x13e/0x1f0
 pci_alloc_irq_vectors_affinity at drivers/pci/msi.c:1208
 pqi_ctrl_init+0x72f/0x1618 [smartpqi]
 pqi_pci_probe.cold.63+0x882/0x892 [smartpqi]
 local_pci_probe+0x7a/0xc0
 work_for_cpu_fn+0x2e/0x50
 process_one_work+0x57e/0xb90
 worker_thread+0x363/0x5b0
 kthread+0x1f4/0x220
 ret_from_fork+0x27/0x50

 -&gt; #0 ((work_completion)(&amp;wfc.work)){+.+.}-{0:0}:
 __lock_acquire+0x2244/0x32a0
 lock_acquire+0x1a2/0x680
 __flush_work+0x4e6/0x630
 work_on_cpu+0x114/0x160
 acpi_processor_ffh_cstate_probe+0x129/0x250
 acpi_processor_evaluate_cst+0x4c8/0x580
 acpi_processor_get_power_info+0x86/0x740
 acpi_processor_hotplug+0xc3/0x140
 acpi_soft_cpu_online+0x102/0x1d0
 cpuhp_invoke_callback+0x197/0x1120
 cpuhp_thread_fun+0x252/0x2f0
 smpboot_thread_fn+0x255/0x440
 kthread+0x1f4/0x220
 ret_from_fork+0x27/0x50

 other info that might help us debug this:

 Chain exists of:
 (work_completion)(&amp;wfc.work) --&gt; cpuhp_state-up --&gt; cpuidle_lock

 Possible unsafe locking scenario:

 CPU0                    CPU1
 ----                    ----
 lock(cpuidle_lock);
                         lock(cpuhp_state-up);
                         lock(cpuidle_lock);
 lock((work_completion)(&amp;wfc.work));

 *** DEADLOCK ***

 3 locks held by cpuhp/1/15:
 #0: ffffffffaf51ab10 (cpu_hotplug_lock){++++}-{0:0}, at: cpuhp_thread_fun+0x69/0x2f0
 #1: ffffffffaf51ad40 (cpuhp_state-up){+.+.}-{0:0}, at: cpuhp_thread_fun+0x69/0x2f0
 #2: ffffffffafa1c0e8 (cpuidle_lock){+.+.}-{3:3}, at: cpuidle_pause_and_lock+0x17/0x20

 Call Trace:
 dump_stack+0xa0/0xea
 print_circular_bug.cold.52+0x147/0x14c
 check_noncircular+0x295/0x2d0
 __lock_acquire+0x2244/0x32a0
 lock_acquire+0x1a2/0x680
 __flush_work+0x4e6/0x630
 work_on_cpu+0x114/0x160
 acpi_processor_ffh_cstate_probe+0x129/0x250
 acpi_processor_evaluate_cst+0x4c8/0x580
 acpi_processor_get_power_info+0x86/0x740
 acpi_processor_hotplug+0xc3/0x140
 acpi_soft_cpu_online+0x102/0x1d0
 cpuhp_invoke_callback+0x197/0x1120
 cpuhp_thread_fun+0x252/0x2f0
 smpboot_thread_fn+0x255/0x440
 kthread+0x1f4/0x220
 ret_from_fork+0x27/0x50

Signed-off-by: Qian Cai &lt;cai@lca.pw&gt;
Tested-by: Borislav Petkov &lt;bp@suse.de&gt;
[ rjw: Subject ]
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>acpi/x86: ignore unspecified bit positions in the ACPI global lock field</title>
<updated>2020-04-17T08:48:45Z</updated>
<author>
<name>Jan Engelhardt</name>
</author>
<published>2020-03-05T12:24:25Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=d56a8ea400a7de2a81d4fcfaa70c4b2f347c1ebf'/>
<id>urn:sha1:d56a8ea400a7de2a81d4fcfaa70c4b2f347c1ebf</id>
<content type='text'>
commit ecb9c790999fd6c5af0f44783bd0217f0b89ec2b upstream.

The value in "new" is constructed from "old" such that all bits defined
as reserved by the ACPI spec[1] are left untouched. But if those bits
do not happen to be all zero, "new &lt; 3" will not evaluate to true.

The firmware of the laptop(s) Medion MD63490 / Akoya P15648 comes with
garbage inside the "FACS" ACPI table. The starting value is
old=0x4944454d, therefore new=0x4944454e, which is &gt;= 3. Mask off
the reserved bits.

[1] https://uefi.org/sites/default/files/resources/ACPI_6_2.pdf

Link: https://bugzilla.kernel.org/show_bug.cgi?id=206553
Cc: All applicable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Jan Engelhardt &lt;jengelh@inai.de&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>x86/ACPI/cstate: Make APCI C1 FFH MWAIT C-state description vendor-neutral</title>
<updated>2018-08-14T22:19:38Z</updated>
<author>
<name>Prarit Bhargava</name>
</author>
<published>2018-08-13T12:43:09Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=3d95b89e573bb8460886ff2ca769b067bfcc50aa'/>
<id>urn:sha1:3d95b89e573bb8460886ff2ca769b067bfcc50aa</id>
<content type='text'>
Commit 5209654a46ee (x86/ACPI/cstate: Allow ACPI C1 FFH MWAIT use on
AMD systems) forgot to update the ACPI C1 idle state description and
tools like turbostat display "ACPI FFH INTEL MWAIT 0x0" which is
quite confusing on an AMD system.

Drop the "INTEL" part from the ACPI C1 FFH MWAIT C-state description
to avoid confusion.

Fixes: 5209654a46ee (x86/ACPI/cstate: Allow ACPI C1 FFH MWAIT use on AMD systems)
Signed-off-by: Prarit Bhargava &lt;prarit@redhat.com&gt;
[ rjw: Subject &amp; changelog ]
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
</entry>
<entry>
<title>x86/acpi: Prevent X2APIC id 0xffffffff from being accounted</title>
<updated>2018-04-17T09:56:31Z</updated>
<author>
<name>Dou Liyang</name>
</author>
<published>2018-04-12T01:40:52Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=10daf10ab154e31237a8c07242be3063fb6a9bf4'/>
<id>urn:sha1:10daf10ab154e31237a8c07242be3063fb6a9bf4</id>
<content type='text'>
RongQing reported that there are some X2APIC id 0xffffffff in his machine's
ACPI MADT table, which makes the number of possible CPU inaccurate.

The reason is that the ACPI X2APIC parser has no sanity check for APIC ID
0xffffffff, which is an invalid id in all APIC types. See "Intel® 64
Architecture x2APIC Specification", Chapter 2.4.1.

Add a sanity check to acpi_parse_x2apic() which ignores the invalid id.

Reported-by: Li RongQing &lt;lirongqing@baidu.com&gt;
Signed-off-by: Dou Liyang &lt;douly.fnst@cn.fujitsu.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: stable@vger.kernel.org
Cc: len.brown@intel.com
Cc: rjw@rjwysocki.net
Cc: hpa@zytor.com
Link: https://lkml.kernel.org/r/20180412014052.25186-1-douly.fnst@cn.fujitsu.com

</content>
</entry>
<entry>
<title>Merge branch 'WIP.x86/asm' into x86/urgent, because the topic is ready</title>
<updated>2018-04-12T07:42:34Z</updated>
<author>
<name>Ingo Molnar</name>
</author>
<published>2018-04-12T07:42:34Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=ef389b734691cdc8beb009dd402135dcdcb86a56'/>
<id>urn:sha1:ef389b734691cdc8beb009dd402135dcdcb86a56</id>
<content type='text'>
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
</entry>
<entry>
<title>x86/apic: Fix signedness bug in APIC ID validity checks</title>
<updated>2018-04-10T14:46:39Z</updated>
<author>
<name>Li RongQing</name>
</author>
<published>2018-04-10T01:16:06Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=a774635db5c430cbf21fa5d2f2df3d23aaa8e782'/>
<id>urn:sha1:a774635db5c430cbf21fa5d2f2df3d23aaa8e782</id>
<content type='text'>
The APIC ID as parsed from ACPI MADT is validity checked with the
apic-&gt;apic_id_valid() callback, which depends on the selected APIC type.

For non X2APIC types APIC IDs &gt;= 0xFF are invalid, but values &gt; 0x7FFFFFFF
are detected as valid. This happens because the 'apicid' argument of the
apic_id_valid() callback is type 'int'. So the resulting comparison

   apicid &lt; 0xFF

evaluates to true for all unsigned int values &gt; 0x7FFFFFFF which are handed
to default_apic_id_valid(). As a consequence, invalid APIC IDs in !X2APIC
mode are considered valid and accounted as possible CPUs.

Change the apicid argument type of the apic_id_valid() callback to u32 so
the evaluation is unsigned and returns the correct result.

[ tglx: Massaged changelog ]

Signed-off-by: Li RongQing &lt;lirongqing@baidu.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: stable@vger.kernel.org
Cc: jgross@suse.com
Cc: Dou Liyang &lt;douly.fnst@cn.fujitsu.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: hpa@zytor.com
Link: https://lkml.kernel.org/r/1523322966-10296-1-git-send-email-lirongqing@baidu.com
</content>
</entry>
<entry>
<title>ACPI, x86/boot: Introduce the -&gt;reduced_hw_early_init() ACPI callback</title>
<updated>2018-03-12T11:32:57Z</updated>
<author>
<name>Andy Shevchenko</name>
</author>
<published>2018-02-20T18:05:05Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=81b53e5ff21e09b42525cfa08f2b0af2b8c5f465'/>
<id>urn:sha1:81b53e5ff21e09b42525cfa08f2b0af2b8c5f465</id>
<content type='text'>
Some ACPI hardware reduced platforms need to initialize certain devices
defined by the ACPI hardware specification even though in principle
those devices should not be present in an ACPI hardware reduced platform.

To allow that to happen, make it possible to override the generic
x86_init callbacks and provide a custom legacy_pic value, add a new
-&gt;reduced_hw_early_init() callback to struct x86_init_acpi and make
acpi_reduced_hw_init() use it.

Signed-off-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Reviewed-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Cc: Eric Biederman &lt;ebiederm@xmission.com&gt;
Cc: Juergen Gross &lt;jgross@suse.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Rafael J . Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: linux-acpi@vger.kernel.org
Link: http://lkml.kernel.org/r/20180220180506.65523-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
</entry>
</feed>
