History log of /openbmc/linux/arch/x86/kernel/apic/local.h (Results 1 – 25 of 42)
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Revision tags: v6.6.67, v6.6.66, v6.6.65, v6.6.64, v6.6.63, v6.6.62, v6.6.61, v6.6.60, v6.6.59, v6.6.58, v6.6.57, v6.6.56, v6.6.55, v6.6.54, v6.6.53, v6.6.52, v6.6.51, v6.6.50, v6.6.49, v6.6.48, v6.6.47, v6.6.46, v6.6.45, v6.6.44, v6.6.43, v6.6.42, v6.6.41, v6.6.40, v6.6.39, v6.6.38, v6.6.37, v6.6.36, v6.6.35, v6.6.34, v6.6.33, v6.6.32, v6.6.31, v6.6.30, v6.6.29, v6.6.28, v6.6.27, v6.6.26, v6.6.25, v6.6.24, v6.6.23, v6.6.16, v6.6.15, v6.6.14, v6.6.13, v6.6.12, v6.6.11, v6.6.10, v6.6.9, v6.6.8, v6.6.7, v6.6.6, v6.6.5, v6.6.4, v6.6.3, v6.6.2, v6.5.11, v6.6.1, v6.5.10, v6.6, v6.5.9, v6.5.8, v6.5.7, v6.5.6, v6.5.5, v6.5.4, v6.5.3
# c900529f 12-Sep-2023 Thomas Zimmermann <tzimmermann@suse.de>

Merge drm/drm-fixes into drm-misc-fixes

Forwarding to v6.6-rc1.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>


Revision tags: v6.5.2, v6.1.51, v6.5.1
# 1687d8ac 30-Aug-2023 Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'x86_apic_for_6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 apic updates from Dave Hansen:
"This includes a very thorough rework of the 'struct apic' handlers

Merge tag 'x86_apic_for_6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 apic updates from Dave Hansen:
"This includes a very thorough rework of the 'struct apic' handlers.
Quite a variety of them popped up over the years, especially in the
32-bit days when odd apics were much more in vogue.

The end result speaks for itself, which is a removal of a ton of code
and static calls to replace indirect calls.

If there's any breakage here, it's likely to be around the 32-bit
museum pieces that get light to no testing these days.

Summary:

- Rework apic callbacks, getting rid of unnecessary ones and
coalescing lots of silly duplicates.

- Use static_calls() instead of indirect calls for apic->foo()

- Tons of cleanups an crap removal along the way"

* tag 'x86_apic_for_6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (64 commits)
x86/apic: Turn on static calls
x86/apic: Provide static call infrastructure for APIC callbacks
x86/apic: Wrap IPI calls into helper functions
x86/apic: Mark all hotpath APIC callback wrappers __always_inline
x86/xen/apic: Mark apic __ro_after_init
x86/apic: Convert other overrides to apic_update_callback()
x86/apic: Replace acpi_wake_cpu_handler_update() and apic_set_eoi_cb()
x86/apic: Provide apic_update_callback()
x86/xen/apic: Use standard apic driver mechanism for Xen PV
x86/apic: Provide common init infrastructure
x86/apic: Wrap apic->native_eoi() into a helper
x86/apic: Nuke ack_APIC_irq()
x86/apic: Remove pointless arguments from [native_]eoi_write()
x86/apic/noop: Tidy up the code
x86/apic: Remove pointless NULL initializations
x86/apic: Sanitize APIC ID range validation
x86/apic: Prepare x2APIC for using apic::max_apic_id
x86/apic: Simplify X2APIC ID validation
x86/apic: Add max_apic_id member
x86/apic: Wrap APIC ID validation into an inline
...

show more ...


Revision tags: v6.1.50, v6.5, v6.1.49, v6.1.48, v6.1.46, v6.1.45
# d8666cf7 08-Aug-2023 Thomas Gleixner <tglx@linutronix.de>

x86/apic: Sanitize APIC ID range validation

Now that everything has apic::max_apic_id set and the eventual update for
the x2APIC case is in place, switch the apic_id_valid() helper to use
apic::max_

x86/apic: Sanitize APIC ID range validation

Now that everything has apic::max_apic_id set and the eventual update for
the x2APIC case is in place, switch the apic_id_valid() helper to use
apic::max_apic_id and remove the apic::apic_id_valid() callback.

[ dhansen: Fix subject typo ]

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Juergen Gross <jgross@suse.com> # Xen PV (dom0 and unpriv. guest)

show more ...


# b5a5ce58 08-Aug-2023 Thomas Gleixner <tglx@linutronix.de>

x86/apic: Prepare x2APIC for using apic::max_apic_id

In order to remove the apic::apic_id_valid() callback and switch to
checking apic::max_apic_id, it is required to update apic::max_apic_id when
t

x86/apic: Prepare x2APIC for using apic::max_apic_id

In order to remove the apic::apic_id_valid() callback and switch to
checking apic::max_apic_id, it is required to update apic::max_apic_id when
the APIC initialization code overrides it via x2apic_set_max_apicid().

Make the existing booleans a bitfield and add a flag which lets the update
function and the core code which switches the driver detect whether the
apic instance wants to have that update or not and apply it if required.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Juergen Gross <jgross@suse.com> # Xen PV (dom0 and unpriv. guest)

show more ...


# 96ae35c7 08-Aug-2023 Thomas Gleixner <tglx@linutronix.de>

x86/apic/x2apic: Share all common IPI functions

Yet more copy and pasta gone.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by:

x86/apic/x2apic: Share all common IPI functions

Yet more copy and pasta gone.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Juergen Gross <jgross@suse.com> # Xen PV (dom0 and unpriv. guest)

show more ...


# e7b6a023 08-Aug-2023 Thomas Gleixner <tglx@linutronix.de>

x86/apic: Move safe wait_icr_idle() next to apic_mem_wait_icr_idle()

Move it next to apic_mem_wait_icr_idle(), rename it so that it's clear what
it does and rewrite it in readable form.

Signed-off-

x86/apic: Move safe wait_icr_idle() next to apic_mem_wait_icr_idle()

Move it next to apic_mem_wait_icr_idle(), rename it so that it's clear what
it does and rewrite it in readable form.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Juergen Gross <jgross@suse.com> # Xen PV (dom0 and unpriv. guest)

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# cfebd007 08-Aug-2023 Thomas Gleixner <tglx@linutronix.de>

x86/apic: Consolidate wait_icr_idle() implementations

Two copies and also needlessly public. Move it into ipi.c so it can be
inlined. Rename it to apic_mem_wait_icr_idle().

Signed-off-by: Thomas Gl

x86/apic: Consolidate wait_icr_idle() implementations

Two copies and also needlessly public. Move it into ipi.c so it can be
inlined. Rename it to apic_mem_wait_icr_idle().

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Juergen Gross <jgross@suse.com> # Xen PV (dom0 and unpriv. guest)

show more ...


# 01363d4f 08-Aug-2023 Thomas Gleixner <tglx@linutronix.de>

x86/apic/ipi: Tidy up the code and fixup comments

Replace the undecodable comment on top of the function, replace the space
consuming zero content comments with useful ones and tidy up the
implement

x86/apic/ipi: Tidy up the code and fixup comments

Replace the undecodable comment on top of the function, replace the space
consuming zero content comments with useful ones and tidy up the
implementation to prevent further eye bleed.

Make __default_send_IPI_shortcut() static as it has no other users.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Juergen Gross <jgross@suse.com> # Xen PV (dom0 and unpriv. guest)

show more ...


# 5a3a46bd 08-Aug-2023 Thomas Gleixner <tglx@linutronix.de>

x86/apic: Mop up apic::apic_id_registered()

Really not a hotpath and again no reason for having a gazillion of empty
callbacks returning 1. Make it return bool and provide one shared
implementation

x86/apic: Mop up apic::apic_id_registered()

Really not a hotpath and again no reason for having a gazillion of empty
callbacks returning 1. Make it return bool and provide one shared
implementation for the remaining users.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Juergen Gross <jgross@suse.com> # Xen PV (dom0 and unpriv. guest)

show more ...


# 9d87f5b6 08-Aug-2023 Thomas Gleixner <tglx@linutronix.de>

x86/apic: Mop up *setup_apic_routing()

default_setup_apic_routing() is a complete misnomer. On 64bit it does the
actual APIC probing and on 32bit it is used to force select the bigsmp APIC
and to em

x86/apic: Mop up *setup_apic_routing()

default_setup_apic_routing() is a complete misnomer. On 64bit it does the
actual APIC probing and on 32bit it is used to force select the bigsmp APIC
and to emit a redundant message in the apic::setup_apic_routing() callback.

Rename the 64bit and 32bit function so they reflect what they are doing and
remove the useless APIC callback.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Juergen Gross <jgross@suse.com> # Xen PV (dom0 and unpriv. guest)

show more ...


# 2f6df03f 08-Aug-2023 Thomas Gleixner <tglx@linutronix.de>

x86/apic: Nuke empty init_apic_ldr() callbacks

apic::init_apic_ldr() is only invoked when the APIC is initialized. So
there is really no point in having:

- Default empty callbacks all over the pl

x86/apic: Nuke empty init_apic_ldr() callbacks

apic::init_apic_ldr() is only invoked when the APIC is initialized. So
there is really no point in having:

- Default empty callbacks all over the place

- Two implementations of the actual LDR init function where one is
just unreadable gunk but does exactly the same as the other.

Make the apic::init_apic_ldr() invocation conditional, remove the empty
callbacks and consolidate the two implementation into one.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Juergen Gross <jgross@suse.com> # Xen PV (dom0 and unpriv. guest)

show more ...


# 79c9a17c 08-Aug-2023 Thomas Gleixner <tglx@linutronix.de>

x86/apic/32: Decrapify the def_bigsmp mechanism

If the system has more than 8 CPUs then XAPIC and the bigsmp APIC driver is
required. This is ensured via:

1) Enumerating all possible CPUs up to N

x86/apic/32: Decrapify the def_bigsmp mechanism

If the system has more than 8 CPUs then XAPIC and the bigsmp APIC driver is
required. This is ensured via:

1) Enumerating all possible CPUs up to NR_CPUS

2) Checking at boot CPU APIC setup time whether the system has more than
8 CPUs and has an XAPIC.

If that's the case then it's attempted to install the bigsmp APIC
driver and a magic variable 'def_to_bigsmp' is set to one.

3) If that magic variable is set and CONFIG_X86_BIGSMP=n and the system
has more than 8 CPUs smp_sanity_check() removes all CPUs >= #8 from
the present and possible mask in the most convoluted way.

This logic is completely broken for the case where the bigsmp driver is
enabled, but not selected due to a command line option specifying the
default APIC. In that case the system boots with default APIC in logical
destination mode and fails to reduce the number of CPUs.

That aside the above which is sprinkled over 3 different places is yet
another piece of art.

It would have been too obvious to check the requirements upfront and limit
nr_cpu_ids _before_ enumerating tons of CPUs and then removing them again.

Implement exactly this. Check the bigsmp requirement when the boot APIC is
registered which happens _before_ ACPI/MPTABLE parsing and limit the number
of CPUs to 8 if it can't be used. Switch it over when the boot CPU apic is
set up if necessary.

[ dhansen: fix nr_cpu_ids off-by-one in default_setup_apic_routing() ]

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Juergen Gross <jgross@suse.com> # Xen PV (dom0 and unpriv. guest)

show more ...


Revision tags: v6.1.44, v6.1.43, v6.1.42, v6.1.41, v6.1.40, v6.1.39, v6.1.38, v6.1.37, v6.1.36, v6.4, v6.1.35, v6.1.34, v6.1.33, v6.1.32, v6.1.31, v6.1.30, v6.1.29, v6.1.28, v6.1.27, v6.1.26, v6.3, v6.1.25, v6.1.24, v6.1.23, v6.1.22, v6.1.21, v6.1.20, v6.1.19, v6.1.18, v6.1.17, v6.1.16, v6.1.15, v6.1.14, v6.1.13, v6.2, v6.1.12, v6.1.11, v6.1.10, v6.1.9, v6.1.8, v6.1.7, v6.1.6, v6.1.5, v6.0.19, v6.0.18, v6.1.4, v6.1.3, v6.0.17, v6.1.2, v6.0.16, v6.1.1, v6.0.15, v6.0.14, v6.0.13, v6.1, v6.0.12, v6.0.11, v6.0.10, v5.15.80, v6.0.9, v5.15.79, v6.0.8, v5.15.78, v6.0.7, v5.15.77, v5.15.76, v6.0.6, v6.0.5, v5.15.75, v6.0.4, v6.0.3, v6.0.2, v5.15.74, v5.15.73, v6.0.1, v5.15.72, v6.0, v5.15.71, v5.15.70, v5.15.69, v5.15.68, v5.15.67, v5.15.66, v5.15.65, v5.15.64, v5.15.63, v5.15.62, v5.15.61, v5.15.60, v5.15.59, v5.19, v5.15.58, v5.15.57, v5.15.56, v5.15.55, v5.15.54, v5.15.53, v5.15.52, v5.15.51, v5.15.50, v5.15.49, v5.15.48, v5.15.47, v5.15.46, v5.15.45, v5.15.44, v5.15.43, v5.15.42, v5.18, v5.15.41, v5.15.40, v5.15.39, v5.15.38, v5.15.37, v5.15.36, v5.15.35, v5.15.34, v5.15.33, v5.15.32, v5.15.31, v5.17, v5.15.30, v5.15.29, v5.15.28, v5.15.27, v5.15.26, v5.15.25, v5.15.24, v5.15.23, v5.15.22, v5.15.21, v5.15.20, v5.15.19, v5.15.18, v5.15.17, v5.4.173, v5.15.16, v5.15.15, v5.16, v5.15.10, v5.15.9, v5.15.8, v5.15.7, v5.15.6, v5.15.5, v5.15.4, v5.15.3, v5.15.2, v5.15.1, v5.15, v5.14.14, v5.14.13, v5.14.12, v5.14.11, v5.14.10, v5.14.9, v5.14.8, v5.14.7, v5.14.6, v5.10.67, v5.10.66, v5.14.5, v5.14.4, v5.10.65, v5.14.3, v5.10.64, v5.14.2, v5.10.63, v5.14.1, v5.10.62, v5.14, v5.10.61, v5.10.60, v5.10.53, v5.10.52, v5.10.51, v5.10.50, v5.10.49, v5.13, v5.10.46, v5.10.43, v5.10.42, v5.10.41, v5.10.40, v5.10.39, v5.4.119, v5.10.36, v5.10.35, v5.10.34, v5.4.116, v5.10.33, v5.12, v5.10.32, v5.10.31, v5.10.30, v5.10.27, v5.10.26, v5.10.25, v5.10.24, v5.10.23, v5.10.22, v5.10.21, v5.10.20, v5.10.19, v5.4.101, v5.10.18, v5.10.17, v5.11, v5.10.16, v5.10.15, v5.10.14
# 4b419325 14-Dec-2020 Dmitry Torokhov <dmitry.torokhov@gmail.com>

Merge branch 'next' into for-linus

Prepare input updates for 5.11 merge window.


Revision tags: v5.10
# 05909cd9 17-Nov-2020 Dmitry Torokhov <dmitry.torokhov@gmail.com>

Merge tag 'v5.9' into next

Sync up with mainline to bring in the latest DTS files.


Revision tags: v5.8.17, v5.8.16
# 62b31a04 15-Oct-2020 Jiri Kosina <jkosina@suse.cz>

Merge branch 'for-5.10/core' into for-linus

- nonblocking read semantics fix for hid-debug


Revision tags: v5.8.15, v5.9, v5.8.14, v5.8.13, v5.8.12, v5.8.11, v5.8.10, v5.8.9
# 0ea8a56d 11-Sep-2020 Rodrigo Vivi <rodrigo.vivi@intel.com>

Merge drm/drm-next into drm-intel-next-queued

Sync drm-intel-gt-next here so we can have an unified fixes flow.

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>


# 1b67fd08 11-Sep-2020 Paolo Bonzini <pbonzini@redhat.com>

Merge tag 'kvmarm-fixes-5.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for Linux 5.9, take #1

- Multiple stolen time fixes, with a new capability to

Merge tag 'kvmarm-fixes-5.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for Linux 5.9, take #1

- Multiple stolen time fixes, with a new capability to match x86
- Fix for hugetlbfs mappings when PUD and PMD are the same level
- Fix for hugetlbfs mappings when PTE mappings are enforced
(dirty logging, for example)
- Fix tracing output of 64bit values

show more ...


Revision tags: v5.8.8
# 9ddb236f 09-Sep-2020 Takashi Iwai <tiwai@suse.de>

Merge branch 'for-linus' into for-next

Back-merge to apply the tasklet conversion patches that are based
on the already applied tasklet API changes on 5.9-rc4.

Signed-off-by: Takashi Iwai <tiwai@su

Merge branch 'for-linus' into for-next

Back-merge to apply the tasklet conversion patches that are based
on the already applied tasklet API changes on 5.9-rc4.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

show more ...


Revision tags: v5.8.7, v5.8.6, v5.4.62
# 6bde8ef5 02-Sep-2020 Takashi Iwai <tiwai@suse.de>

Merge branch 'topic/tasklet-convert' into for-linus

Pull tasklet API conversions.

Signed-off-by: Takashi Iwai <tiwai@suse.de>


# ead5d1f4 01-Sep-2020 Jiri Kosina <jkosina@suse.cz>

Merge branch 'master' into for-next

Sync with Linus' branch in order to be able to apply fixups
of more recent patches.


Revision tags: v5.8.5, v5.8.4, v5.4.61
# 3bec5b6a 25-Aug-2020 Mark Brown <broonie@kernel.org>

Merge tag 'v5.9-rc2' into regulator-5.9

Linux 5.9-rc2


# 1959ba4e 25-Aug-2020 Mark Brown <broonie@kernel.org>

Merge tag 'v5.9-rc2' into asoc-5.9

Linux 5.9-rc2


# 2d9ad4cf 25-Aug-2020 Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

Merge tag 'v5.9-rc2' into drm-misc-fixes

Backmerge requested by Tomi for a fix to omap inconsistent
locking state issue, and because we need at least v5.9-rc2 now.

Signed-off-by: Maarten Lankhorst

Merge tag 'v5.9-rc2' into drm-misc-fixes

Backmerge requested by Tomi for a fix to omap inconsistent
locking state issue, and because we need at least v5.9-rc2 now.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

show more ...


Revision tags: v5.8.3, v5.4.60, v5.8.2, v5.4.59
# d85ddd13 18-Aug-2020 Maxime Ripard <maxime@cerno.tech>

Merge v5.9-rc1 into drm-misc-next

Sam needs 5.9-rc1 to have dev_err_probe in to merge some patches.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>


Revision tags: v5.8.1, v5.4.58
# 97d052ea 10-Aug-2020 Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'locking-urgent-2020-08-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull locking updates from Thomas Gleixner:
"A set of locking fixes and updates:

- Untangle the hea

Merge tag 'locking-urgent-2020-08-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull locking updates from Thomas Gleixner:
"A set of locking fixes and updates:

- Untangle the header spaghetti which causes build failures in
various situations caused by the lockdep additions to seqcount to
validate that the write side critical sections are non-preemptible.

- The seqcount associated lock debug addons which were blocked by the
above fallout.

seqcount writers contrary to seqlock writers must be externally
serialized, which usually happens via locking - except for strict
per CPU seqcounts. As the lock is not part of the seqcount, lockdep
cannot validate that the lock is held.

This new debug mechanism adds the concept of associated locks.
sequence count has now lock type variants and corresponding
initializers which take a pointer to the associated lock used for
writer serialization. If lockdep is enabled the pointer is stored
and write_seqcount_begin() has a lockdep assertion to validate that
the lock is held.

Aside of the type and the initializer no other code changes are
required at the seqcount usage sites. The rest of the seqcount API
is unchanged and determines the type at compile time with the help
of _Generic which is possible now that the minimal GCC version has
been moved up.

Adding this lockdep coverage unearthed a handful of seqcount bugs
which have been addressed already independent of this.

While generally useful this comes with a Trojan Horse twist: On RT
kernels the write side critical section can become preemtible if
the writers are serialized by an associated lock, which leads to
the well known reader preempts writer livelock. RT prevents this by
storing the associated lock pointer independent of lockdep in the
seqcount and changing the reader side to block on the lock when a
reader detects that a writer is in the write side critical section.

- Conversion of seqcount usage sites to associated types and
initializers"

* tag 'locking-urgent-2020-08-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (25 commits)
locking/seqlock, headers: Untangle the spaghetti monster
locking, arch/ia64: Reduce <asm/smp.h> header dependencies by moving XTP bits into the new <asm/xtp.h> header
x86/headers: Remove APIC headers from <asm/smp.h>
seqcount: More consistent seqprop names
seqcount: Compress SEQCNT_LOCKNAME_ZERO()
seqlock: Fold seqcount_LOCKNAME_init() definition
seqlock: Fold seqcount_LOCKNAME_t definition
seqlock: s/__SEQ_LOCKDEP/__SEQ_LOCK/g
hrtimer: Use sequence counter with associated raw spinlock
kvm/eventfd: Use sequence counter with associated spinlock
userfaultfd: Use sequence counter with associated spinlock
NFSv4: Use sequence counter with associated spinlock
iocost: Use sequence counter with associated spinlock
raid5: Use sequence counter with associated spinlock
vfs: Use sequence counter with associated spinlock
timekeeping: Use sequence counter with associated raw spinlock
xfrm: policy: Use sequence counters with associated lock
netfilter: nft_set_rbtree: Use sequence counter with associated rwlock
netfilter: conntrack: Use sequence counter with associated spinlock
sched: tasks: Use sequence counter with associated spinlock
...

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