x86/i8259: Skip probing when ACPI/MADT advertises PCAT compatibility

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 <dlazar@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: David Lazar <dlazar@gmail.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Cc: stable@vger.kernel.org
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218003
Link: https://lore.kernel.org/r/875y2u5s8g.ffs@tglx

x86/irq/i8259: Fix kernel-doc annotation warning

Fix this warning:

arch/x86/kernel/i8259.c:235: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
* ELCR registers (0x4d0, 0x4d1) control edge/level of IRQ
CC arch/x86/kernel/irqinit.o

Signed-off-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20230830131211.88226-1-vincenzopalazzodev@gmail.com

x86/i8259: Mark legacy PIC interrupts with IRQ_LEVEL

Baoquan reported that after triggering a crash the subsequent crash-kernel
fails to boot about half of the time. It triggers a NULL pointer
dereference in the periodic tick code.

This happens because the legacy timer interrupt (IRQ0) is resent in
software which happens in soft interrupt (tasklet) context. In this context
get_irq_regs() returns NULL which leads to the NULL pointer dereference.

The reason for the resend is a spurious APIC interrupt on the IRQ0 vector
which is captured and leads to a resend when the legacy timer interrupt is
enabled. This is wrong because the legacy PIC interrupts are level
triggered and therefore should never be resent in software, but nothing
ever sets the IRQ_LEVEL flag on those interrupts, so the core code does not
know about their trigger type.

Ensure that IRQ_LEVEL is set when the legacy PCI interrupts are set up.

Fixes: a4633adcdbc1 ("[PATCH] genirq: add genirq sw IRQ-retrigger")
Reported-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Baoquan He <bhe@redhat.com>
Link: https://lore.kernel.org/r/87mt6rjrra.ffs@tglx

x86/i8259: Make default_legacy_pic static

The symbol is not used outside of the file, so mark it static.

Signed-off-by: Chen Lifu <chenlifu@huawei.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20220823021958.3052493-1-chenlifu@huawei.com

x86: Avoid magic number with ELCR register accesses

Define PIC_ELCR1 and PIC_ELCR2 macros for accesses to the ELCR registers
implemented by many chipsets in their embedded 8259A PIC cores, avoiding
magic numbers that are difficult to handle, and complementing the macros
we already have for registers originally defined with discrete 8259A PIC
implementations. No functional change.

Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/alpine.DEB.2.21.2107200237300.9461@angie.orcam.me.uk

x86/i8259: Use printk_deferred() to prevent deadlock

0day reported a possible circular locking dependency:

Chain exists of:
&irq_desc_lock_class --> console_owner --> &port_lock_key

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&port_lock_key);
lock(console_owner);
lock(&port_lock_key);
lock(&irq_desc_lock_class);

The reason for this is a printk() in the i8259 interrupt chip driver
which is invoked with the irq descriptor lock held, which reverses the
lock operations vs. printk() from arbitrary contexts.

Switch the printk() to printk_deferred() to avoid that.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/87365abt2v.fsf@nanos.tec.linutronix.de

mm: reorder includes after introduction of linux/pgtable.h

The replacement of <asm/pgrable.h> with <linux/pgtable.h> made the include
of the latter in the middle of asm includes. Fix this up with the aid of
the below script and manual adjustments here and there.

import sys
import re

if len(sys.argv) is not 3:
print "USAGE: %s <file> <header>" % (sys.argv[0])
sys.exit(1)

hdr_to_move="#include <linux/%s>" % sys.argv[2]
moved = False
in_hdrs = False

with open(sys.argv[1], "r") as f:
lines = f.readlines()
for _line in lines:
line = _line.rstrip('
')
if line == hdr_to_move:
continue
if line.startswith("#include <linux/"):
in_hdrs = True
elif not moved and in_hdrs:
moved = True
print hdr_to_move
print line

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200514170327.31389-4-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: introduce include/linux/pgtable.h

The include/linux/pgtable.h is going to be the home of generic page table
manipulation functions.

Start with moving asm-generic/pgtable.h to include/linux/pgtable.h and
make the latter include asm/pgtable.h.

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200514170327.31389-3-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

x86: Don't include linux/irq.h from asm/hardirq.h

The next patch in this series will have to make the definition of
irq_cpustat_t available to entering_irq().

Inclusion of asm/hardirq.h into asm/apic.h would cause circular header
dependencies like

asm/smp.h
asm/apic.h
asm/hardirq.h
linux/irq.h
linux/topology.h
linux/smp.h
asm/smp.h

or

linux/gfp.h
linux/mmzone.h
asm/mmzone.h
asm/mmzone_64.h
asm/smp.h
asm/apic.h
asm/hardirq.h
linux/irq.h
linux/irqdesc.h
linux/kobject.h
linux/sysfs.h
linux/kernfs.h
linux/idr.h
linux/gfp.h

and others.

This causes compilation errors because of the header guards becoming
effective in the second inclusion: symbols/macros that had been defined
before wouldn't be available to intermediate headers in the #include chain
anymore.

A possible workaround would be to move the definition of irq_cpustat_t
into its own header and include that from both, asm/hardirq.h and
asm/apic.h.

However, this wouldn't solve the real problem, namely asm/harirq.h
unnecessarily pulling in all the linux/irq.h cruft: nothing in
asm/hardirq.h itself requires it. Also, note that there are some other
archs, like e.g. arm64, which don't have that #include in their
asm/hardirq.h.

Remove the linux/irq.h #include from x86' asm/hardirq.h.

Fix resulting compilation errors by adding appropriate #includes to *.c
files as needed.

Note that some of these *.c files could be cleaned up a bit wrt. to their
set of #includes, but that should better be done from separate patches, if
at all.

Signed-off-by: Nicolai Stange <nstange@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

x86/irq/vector: Initialize matrix allocator

Initialize the matrix allocator and add the proper accounting points to the
code.

No functional change, just preparation.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Tested-by: Yu Chen <yu.c.chen@intel.com>
Acked-by: Juergen Gross <jgross@suse.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rui Zhang <rui.zhang@intel.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Len Brown <lenb@kernel.org>
Link: https://lkml.kernel.org/r/20170913213155.108410660@linutronix.de

x86: i8259: export legacy_pic symbol

The classic PC rtc-coms driver has a workaround for broken ACPI device
nodes for it which lack an irq resource. This workaround used to
unconditionally hardcode the irq to 8 in these cases.

This was causing irq conflict problems on systems without a legacy-pic
so a recent patch added an if (nr_legacy_irqs()) guard to the
workaround to avoid this irq conflict.

nr_legacy_irqs() uses the legacy_pic symbol under the hood causing
an undefined symbol error if the rtc-cmos code is build as a module.

This commit exports the legacy_pic symbol to fix this.

Cc: rtc-linux@googlegroups.com
Cc: alexandre.belloni@free-electrons.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

x86/irq: Probe for PIC presence before allocating descs for legacy IRQs

Commit d32932d02e18 ("x86/irq: Convert IOAPIC to use hierarchical irqdomain
interfaces") brought a regression for Hyper-V Gen2 instances. These
instances don't have i8259 legacy PIC but they use legacy IRQs for serial
port, rtc, and acpi. With this commit included we end up with these IRQs
not initialized. Earlier, there was a special workaround for legacy IRQs
in mp_map_pin_to_irq() doing mp_irqdomain_map() without looking at
nr_legacy_irqs() and now we fail in __irq_domain_alloc_irqs() when
irq_domain_alloc_descs() returns -EEXIST.

The essence of the issue seems to be that early_irq_init() calls
arch_probe_nr_irqs() to figure out the number of legacy IRQs before
we probe for i8259 and gets 16. Later when init_8259A() is called we switch
to NULL legacy PIC and nr_legacy_irqs() starts to return 0 but we already
have 16 descs allocated.

Solve the issue by separating i8259 probe from init and calling it in
arch_probe_nr_irqs() before we actually use nr_legacy_irqs() information.

Fixes: d32932d02e18 ("x86/irq: Convert IOAPIC to use hierarchical irqdomain interfaces")
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1446543614-3621-1-git-send-email-vkuznets@redhat.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

x86/asm/entry/irq: Clean up IRQn_VECTOR macros

Since the ISA irqs are in a single block, use
ISA_IRQ_VECTOR(irq) instead of individual macros.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1431185813-15413-5-git-send-email-brgerst@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/irq: Fix XT-PIC-XT-PIC in /proc/interrupts

Fix duplicate XT-PIC seen in /proc/interrupts on x86 systems
that make use of 8259A Programmable Interrupt Controllers.
Specifically convert output like this:

CPU0
0: 76573 XT-PIC-XT-PIC timer
1: 11 XT-PIC-XT-PIC i8042
2: 0 XT-PIC-XT-PIC cascade
4: 8 XT-PIC-XT-PIC serial
6: 3 XT-PIC-XT-PIC floppy
7: 0 XT-PIC-XT-PIC parport0
8: 1 XT-PIC-XT-PIC rtc0
10: 448 XT-PIC-XT-PIC fddi0
12: 23 XT-PIC-XT-PIC eth0
14: 2464 XT-PIC-XT-PIC ide0
NMI: 0 Non-maskable interrupts
ERR: 0

to one like this:

CPU0
0: 122033 XT-PIC timer
1: 11 XT-PIC i8042
2: 0 XT-PIC cascade
4: 8 XT-PIC serial
6: 3 XT-PIC floppy
7: 0 XT-PIC parport0
8: 1 XT-PIC rtc0
10: 145 XT-PIC fddi0
12: 31 XT-PIC eth0
14: 2245 XT-PIC ide0
NMI: 0 Non-maskable interrupts
ERR: 0

that is one like we used to have from ~2.2 till it was changed
sometime.

The rationale is there is no value in this duplicate
information, it merely clutters output and looks ugly. We only
have one handler for 8259A interrupts so there is no need to
give it a name separate from the name already given to
irq_chip.

We could define meaningful names for handlers based on bits in
the ELCR register on systems that have it or the value of the
LTIM bit we use in ICW1 otherwise (hardcoded to 0 though with
MCA support gone), to tell edge-triggered and level-triggered
inputs apart. While that information does not affect 8259A
interrupt handlers it could help people determine which lines
are shareable and which are not. That is material for a
separate change though.

Any tools that parse /proc/interrupts are supposed not to be
affected since it was many years we used the format this change
converts back to.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/alpine.LFD.2.11.1410260147190.21390@eddie.linux-mips.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86, irq, pic: Probe for legacy PIC and set legacy_pic appropriately

The legacy PIC may or may not be available and we need a mechanism to
detect the existence of the legacy PIC that is applicable for all
hardware (both physical as well as virtual) currently supported by
Linux.

On Hyper-V, when our legacy firmware presented to the guests, emulates
the legacy PIC while when our EFI based firmware is presented we do
not emulate the PIC. To support Hyper-V EFI firmware, we had to set
the legacy_pic to the null_legacy_pic since we had to bypass PIC based
calibration in the early boot code. While, on the EFI firmware, we
know we don't emulate the legacy PIC, we need a generic mechanism to
detect the presence of the legacy PIC that is not based on boot time
state - this became apparent when we tried to get kexec to work on
Hyper-V EFI firmware.

This patch implements the proposal put forth by H. Peter Anvin
<hpa@linux.intel.com>: Write a known value to the PIC data port and
read it back. If the value read is the value written, we do have the
PIC, if not there is no PIC and we can safely set the legacy_pic to
null_legacy_pic. Since the read from an unconnected I/O port returns
0xff, we will use ~(1 << PIC_CASCADE_IR) (0xfb: mask all lines except
the cascade line) to probe for the existence of the PIC.

In version V1 of the patch, I had cleaned up the code based on comments from Peter.
In version V2 of the patch, I have addressed additional comments from Peter.
In version V3 of the patch, I have addressed Jan's comments (JBeulich@suse.com).
In version V4 of the patch, I have addressed additional comments from Peter.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Link: http://lkml.kernel.org/r/1397501029-29286-1-git-send-email-kys@microsoft.com
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

x86/irq: Correct comment about i8259 initialization

0x30-0x3f have been used for ISA interrupts on i386 as well
since 5 years ago, but old comments about i8259 initialization
were still referring to the old i386 usage of this port range.

Signed-off-by: Yanchuan Nian <ycnian@gmail.com>
Cc: yinghai@kernel.org
Cc: pavel@suse.cz
Link: http://lkml.kernel.org/r/1378257924-29446-1-git-send-email-ycnian@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/irq/i8259: Fix incorrect comment

Signed-off-by: Yuanhan Liu <yliu.null@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Disintegrate asm/system.h for X86

Disintegrate asm/system.h for X86.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
cc: x86@kernel.org

atomic: use <linux/atomic.h>

This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>

Signed-off-by: Arun Sharma <asharma@fb.com>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

x86: Use syscore_ops instead of sysdev classes and sysdevs

Some subsystems in the x86 tree need to carry out suspend/resume and
shutdown operations with one CPU on-line and interrupts disabled and
they define sysdev classes and sysdevs or sysdev drivers for this
purpose. This leads to unnecessarily complicated code and excessive
memory usage, so switch them to using struct syscore_ops objects for
this purpose instead.

Generally, there are three categories of subsystems that use
sysdevs for implementing PM operations: (1) subsystems whose
suspend/resume callbacks ignore their arguments entirely (the
majority), (2) subsystems whose suspend/resume callbacks use their
struct sys_device argument, but don't really need to do that,
because they can be implemented differently in an arguably simpler
way (io_apic.c), and (3) subsystems whose suspend/resume callbacks
use their struct sys_device argument, but the value of that argument
is always the same and could be ignored (microcode_core.c). In all
of these cases the subsystems in question may be readily converted to
using struct syscore_ops objects for power management and shutdown.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@elte.hu>

x86: Cleanup the genirq name space

genirq is switching to a consistent name space for the irq related
functions. Convert x86. Conversion was done with coccinelle.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

x86: i8259: Convert to new irq_chip functions

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@elte.hu>

x86, i8259: Only register sysdev if we have a real 8259 PIC

My platform makes use of the null_legacy_pic choice and oopses when doing
a shutdown as the shutdown code goes through all the registered sysdevs
and calls their shutdown method which in my case poke on a non-existing
i8259. Imho the i8259 specific sysdev should only be registered if the
i8259 is actually there.

Do not register the sysdev function when the null_legacy_pic is used so
that the i8259 resume, suspend and shutdown functions are not called.

Signed-off-by: Adam Lackorzynski <adam@os.inf.tu-dresden.de>
LKML-Reference: <201007202218.o6KMIJ3m020955@imap1.linux-foundation.org>
Cc: Jacob Pan <jacob.jun.pan@intel.com>
Cc: <stable@kernel.org> 2.6.34
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

x86, pic: Fix section mismatch in legacy pic

Move legacy_pic chip dummy functions out of init section as they might
be referenced at run time.

Signed-off-by: Jacob Pan <jacob.jun.pan@intel.com>
LKML-Reference: <43F901BD926A4E43B106BF17856F0755A318D3AA@orsmsx508.amr.corp.intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

x86, pic: Make use of legacy_pic abstraction

This patch replaces legacy PIC-related global variable and functions
with the new legacy_pic abstraction.

Signed-off-by: Jacob Pan <jacob.jun.pan@intel.com>
LKML-Reference: <43F901BD926A4E43B106BF17856F07559FB80D04@orsmsx508.amr.corp.intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

x86, pic: Introduce legacy_pic abstraction

This patch makes i8259A like legacy programmable interrupt controller
code into a driver so that legacy pic functions can be selected at
runtime based on platform information, such as HW subarchitecure ID.
Default structure of legacy_pic maintains the current code path for
x86pc.

Signed-off-by: Jacob Pan <jacob.jun.pan@intel.com>
LKML-Reference: <43F901BD926A4E43B106BF17856F07559FB80D03@orsmsx508.amr.corp.intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

x86: Convert i8259_lock to raw_spinlock

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

x86: refactor x86_quirks support

Impact: cleanup

Make x86_quirks support more transparent. The highlevel
methods are now named:

extern void x86_quirk_pre_intr_init(void);
extern void x86_quirk_intr_init(void);

extern void x86_quirk_trap_init(void);

extern void x86_quirk_pre_time_init(void);
extern void x86_quirk_time_init(void);

This makes it clear that if some platform extension has to
do something here that it is considered ... weird, and is
discouraged.

Also remove arch_hooks.h and move it into setup.h (and other
header files where appropriate).

Signed-off-by: Ingo Molnar <mingo@elte.hu>

x86: i8259.c fix style problems

Impact: cleanup

Fix:

WARNING: Use #include <linux/acpi.h> instead of <asm/acpi.h>
WARNING: Use #include <linux/io.h> instead of <asm/io.h>
WARNING: Use #include <linux/delay.h> instead of <asm/delay.h>
ERROR: code indent should use tabs where possible

total: 1 errors, 3 warnings

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

x64, x2apic/intr-remap: 8259 specific mask/unmask routines

8259 specific mask/unmask routines which be used later while enabling
interrupt-remapping.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: akpm@linux-foundation.org
Cc: arjan@linux.intel.com
Cc: andi@firstfloor.org
Cc: ebiederm@xmission.com
Cc: jbarnes@virtuousgeek.org
Cc: steiner@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>

i8259: fix final ugliness

Introduce IRQx_VECTOR on 32-bit, so that #ifdef noise is kept
down. There should be no object code change.

[ mingo@elte.hu: merged to x86/irq not x86/i8259 due to x86/irq having
restructured the vector code into asm-x86/irq_vectors.h, which this
patch touches. ]

Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

x86: i8259: cleanup codingstyle

Signed-off-by: Pavel Machek <pavel@suse.cz>
Cc: macro@ds2.pg.gda.pl
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

x86: i8259.c: remove trivial ifdefs

Remove #ifdefs where the only difference is formatting of comments.

Signed-off-by: Pavel Machek <pavel@suse.cz>
Cc: macro@ds2.pg.gda.pl
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

x86: i8259.c: remove #ifdefs around includes

Remove #ifdefs around includes; including too much should be always
safe.

Signed-off-by: Pavel Machek <pavel@suse.cz>
Cc: macro@ds2.pg.gda.pl
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

x86: automatical unification of i8259.c

Make conversion of i8259 very mechanical -- i8259 was generated by
diff -D, with too different parts left in i8259_32 and
i8259_64.c. Only "by hand" changes were removal of #ifdef from middle
of the comment (prevented compilation) and removal of one static to
allow splitting into files.

Of course, it will need some cleanups now, and those will follow.

Signed-of-by: Pavel Machek <pavel@suse.cz>

x86: i8259: cleanup codingstyle

Signed-off-by: Pavel Machek <pavel@suse.cz>
Cc: macro@ds2.pg.gda.pl
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

x86: i8259.c: remove trivial ifdefs

Remove #ifdefs where the only difference is formatting of comments.

Signed-off-by: Pavel Machek <pavel@suse.cz>
Cc: macro@ds2.pg.gda.pl
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

x86: i8259.c: remove #ifdefs around includes

Remove #ifdefs around includes; including too much should be always
safe.

Signed-off-by: Pavel Machek <pavel@suse.cz>
Cc: macro@ds2.pg.gda.pl
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

x86: automatical unification of i8259.c

Make conversion of i8259 very mechanical -- i8259 was generated by