Replace calls to bus_generic_attach with bus_attach_children

Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D47675

Replace calls to bus_generic_probe with bus_identify_children

Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D47674

Use the correct idle routine on recent AMD EPYC servers

We have been incorrectly choosing the "hlt" idle method on modern AMD
EPYC servers for C1 idle. This is because AMD also uses the Functional
F

Use the correct idle routine on recent AMD EPYC servers

We have been incorrectly choosing the "hlt" idle method on modern AMD
EPYC servers for C1 idle. This is because AMD also uses the Functional
Fixed Hardware interface. Due to not parsing the table properly for
AMD, and due to a weird quirk where the mwait latency for C1 is
mis-interpreted as the latency for hlt, we wind up choosing hlt for
c1, which has a far higher wake up latency (similar to IO) of roughly
400us on my test system (AMD 7502P).

This patch fixes this by:

- Looking for AMD in addition to Intel in the FFH
(Note the vendor id of "2" for AMD is not publically documented, but
AMD has confirmed they are using "2" and has promised to document it.)

- Using mwait on AMD when specified in the table, and when CPUid says
its supported

- Fixing a weird issue where we copy the contents of cx_ptr for C1 and
when moving to C2, we do not reinitialize cx_ptr. This leads to
mwait being selected, and ignoring the specified i/o halt method
unless we clear mwait before looking at the table for C2.

Differential Revision: https://reviews.freebsd.org/D47444
Reviewed by: dab, kib, vangyzen
Sponsored by: Netflix

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acpi_cpu: Reduce BUS_MASTER_RLD manipulations

Instead of setting and clearing BUS_MASTER_RLD register on every C3
state enter/exit, set it only once if the system supports C3 state
and we are going

acpi_cpu: Reduce BUS_MASTER_RLD manipulations

Instead of setting and clearing BUS_MASTER_RLD register on every C3
state enter/exit, set it only once if the system supports C3 state
and we are going to "disable" bus master arbitration while in it.

This is what Linux does for the past 14 years, and for even more time
this register is not implemented in a relevant hardware. Same time
since this is only a single bit in a bigger register, ACPI has to
do take a global lock and do read-modify-write for it, that is too
expensive, saved only by C3 not entered frequently, but enough to be
seen in idle system CPU profiles.

MFC after: 1 month

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sys: Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

acpi: Create cppc_notify sysctl before it is checked

Reported by: Henrix
Reviewed by: jhb
Differential Revision: https://reviews.freebsd.org/D37081

acpi: Put CPPC workaround behind i386/amd64 if def

While CPPC is available on arm64 platforms with ACPI we don't know if we
need to work around issues with firmware there.

acpi: Tell SMM we will handle CPPC notifications

Buggy SMM implementations can hang while processing CPPC notifications.
This leads to some laptops (notably Thinkpads) hanging when the
hwpstate_inte

acpi: Tell SMM we will handle CPPC notifications

Buggy SMM implementations can hang while processing CPPC notifications.
This leads to some laptops (notably Thinkpads) hanging when the
hwpstate_intel driver is loaded.

Tell the SMM that we will handle CPPC notifications as described in:

- Intel® Processor Vendor-Specific ACPI
- Intel® 64 and IA-32 Architectures Software Developer’s Manual

CPPC events default to masked (disabled) so while we do not do any
handling right now this does not seem to lead to any issues.

This approach was found via this Linux Kernel patch:
https://lkml.org/lkml/2016/3/17/563

PR: 253288
Reviewed by: imp, jhb
Sponsored by: Modirum
Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D36699

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acpi: Remove unused devclass arguments to DRIVER_MODULE.

acpi_cpu: Use device_get_devclass to find devclass in attach.

Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D34988

xen/acpi: upload Cx and Px data to Xen

When FreeBSD is running as dom0 (initial domain) on a Xen system it
has access to the native ACPI tables and is the OSPM. However the
hypervisor is the entity

xen/acpi: upload Cx and Px data to Xen

When FreeBSD is running as dom0 (initial domain) on a Xen system it
has access to the native ACPI tables and is the OSPM. However the
hypervisor is the entity in charge of the CPU idle and frequency
states, and in order to perform this duty it requires information
found the ACPI dynamic tables that can only be parsed by the OSPM.

Introduce a new Xen specific ACPI driver to fetch the Processor
related information and upload it to Xen. Note that this driver needs
to take precedence over the generic ACPI CPU driver when running as
dom0, so downgrade the probe score of the native driver to
BUS_PROBE_DEFAULT in order for the Xen specific driver to use
BUS_PROBE_SPECIFIC.

Tested on an Intel NUC to successfully parse and upload both the Cx and
Px states to Xen.

Sponsored by: Citrix Systems R&D
Reviewed by: jhb kib
Differential revision: https://reviews.freebsd.org/D34841

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acpica: Remove CTLFLAG_NEEDGIANT from most sysctls.

MFC after: 2 weeks

acpi_cpu: Replace Giant with bus_topo_lock.

Check cpu_softc is not NULL before dereferencing

In the acpi_cpu_postattach SYSINIT function cpu_softc may be NULL, e.g.
on arm64 when booting from FDT. Check it is not NULL at the start of
the func

Check cpu_softc is not NULL before dereferencing

In the acpi_cpu_postattach SYSINIT function cpu_softc may be NULL, e.g.
on arm64 when booting from FDT. Check it is not NULL at the start of
the function so we don't try to dereference a NULL pointer.

Sponsored by: The FreeBSD Foundation

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acpi_cpu: Fix panic if some CPU devices are disabled.

While there, remove couple unneeded global variables.

acpi_cpu: Make device unit numbers match OS CPU IDs.

There are already APIC ID, ACPI ID and OS ID for each CPU. In perfect
world all of those may match, but at least for SuperMicro server boards
no

acpi_cpu: Make device unit numbers match OS CPU IDs.

There are already APIC ID, ACPI ID and OS ID for each CPU. In perfect
world all of those may match, but at least for SuperMicro server boards
none of them do. Plus none of them match the CPU devices listing order
by ACPI. Previous code used the ACPI device listing order to number
cpuX devices. It looked nice from NewBus perspective, but introduced
4th different set of IDs. Extremely confusing one, since in some places
the device unit numbers were treated as OS CPU IDs (coretemp), but not
in others (sysctl dev.cpu.X.%location).

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Move time math out of disabled interrupts sections.

We don't need the result before next sleep time, so no reason to
additionally increase interrupt latency.

While there, remove extra PM ticks to m

Move time math out of disabled interrupts sections.

We don't need the result before next sleep time, so no reason to
additionally increase interrupt latency.

While there, remove extra PM ticks to microseconds conversion, making
C2/C3 sleep times look 4 times smaller than really. The conversion
is already done by AcpiGetTimerDuration(). Now I see reported sleep
times up to 0.5s, just as expected for planned 2 wakeups per second.

MFC after: 1 month

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Do not read timer extra time when MWAIT is used.

When we enter C2+ state via memory read, it may take chipset some
time to stop CPU. Extra register read covers that time. But MWAIT
makes CPU stop

Do not read timer extra time when MWAIT is used.

When we enter C2+ state via memory read, it may take chipset some
time to stop CPU. Extra register read covers that time. But MWAIT
makes CPU stop immediately, so we don't need to waste time after
wakeup with interrupts still disabled, increasing latency.

On my system it reduces ping localhost latency, waking up all CPUs
once a second, from 277us to 242us.

MFC after: 1 month

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Change mwait_bm_avoidance use to match Linux.

Even though the information is very limited, it seems the intent of
this flag is to control ACPI_BITREG_BUS_MASTER_STATUS use for C3,
not force ACPI_BIT

Change mwait_bm_avoidance use to match Linux.

Even though the information is very limited, it seems the intent of
this flag is to control ACPI_BITREG_BUS_MASTER_STATUS use for C3,
not force ACPI_BITREG_ARB_DISABLE manipulations for C2, where it was
never needed, and which register not really doing anything for years.
It wasted lots of CPU time on congested global ACPI hardware lock
when many CPU cores were trying to enter/exit deep C-states same time.

On idle 80-core system it pushed ping localhost latency up to 20ms,
since badport_bandlim() via counter_ratecheck() wakes up all CPUs
same time once a second just to synchronously reset the counters.
Now enabling C-states increases the latency from 0.1 to just 0.25ms.

Discussed with: kib
MFC after: 1 month

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acpica: clean up empty lines in .c and .h files

Merge ^/head r358269 through r358399.

Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (17 of many)

r357614 added CTLFLAG_NEEDGIANT to make it easier to find nodes that are
still not MPSAFE (or already are but aren’t properly mark

Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (17 of many)

r357614 added CTLFLAG_NEEDGIANT to make it easier to find nodes that are
still not MPSAFE (or already are but aren’t properly marked).
Use it in preparation for a general review of all nodes.

This is non-functional change that adds annotations to SYSCTL_NODE and
SYSCTL_PROC nodes using one of the soon-to-be-required flags.

Mark all obvious cases as MPSAFE. All entries that haven't been marked
as MPSAFE before are by default marked as NEEDGIANT

Approved by: kib (mentor, blanket)
Commented by: kib, gallatin, melifaro
Differential Revision: https://reviews.freebsd.org/D23718

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Merge ^/head r339670 through r339812.

Distinguish _CID match and _HID match and make lower priority probe
when _CID match.

Reviewed by: jhb, imp
Differential Revision:https://reviews.freebsd.org/D16468

Use device_quiet_children to silence verbose CPU probe messages.

Have cpu0 be noisy, but all the other CPU devices be quiet on boot.