Commit Graph

713 Commits

Author SHA1 Message Date
John Baldwin
80fe25f150 Remove the LSOL26CALLS_SEL constant.
It is no longer used after SVR4/i386 ABI support was removed.

Reported by:	kib
2017-04-25 23:19:27 +00:00
Gleb Smirnoff
83c9dea1ba - Remove 'struct vmmeter' from 'struct pcpu', leaving only global vmmeter
in place.  To do per-cpu stats, convert all fields that previously were
  maintained in the vmmeters that sit in pcpus to counter(9).
- Since some vmmeter stats may be touched at very early stages of boot,
  before we have set up UMA and we can do counter_u64_alloc(), provide an
  early counter mechanism:
  o Leave one spare uint64_t in struct pcpu, named pc_early_dummy_counter.
  o Point counter(9) fields of vmmeter to pcpu[0].pc_early_dummy_counter,
    so that at early stages of boot, before counters are allocated we already
    point to a counter that can be safely written to.
  o For sparc64 that required a whole dummy pcpu[MAXCPU] array.

Further related changes:
- Don't include vmmeter.h into pcpu.h.
- vm.stats.vm.v_swappgsout and vm.stats.vm.v_swappgsin changed to 64-bit,
  to match kernel representation.
- struct vmmeter hidden under _KERNEL, and only vmstat(1) is an exclusion.

This is based on benno@'s 4-year old patch:
https://lists.freebsd.org/pipermail/freebsd-arch/2013-July/014471.html

Reviewed by:	kib, gallatin, marius, lidl
Differential Revision:	https://reviews.freebsd.org/D10156
2017-04-17 17:34:47 +00:00
Gleb Smirnoff
9ed01c32e0 All these files need sys/vmmeter.h, but now they got it implicitly
included via sys/pcpu.h.
2017-04-17 17:07:00 +00:00
Konstantin Belousov
366bb48985 Correct calculation of the entry->free_down in the invariants-checking
code.

Reported by:	maxim
Found by:	PVS studio scan
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2017-04-14 15:16:41 +00:00
Patrick Kelsey
67d955aab4 Corrected misspelled versions of rendezvous.
The MFC will include a compat definition of smp_no_rendevous_barrier()
that calls smp_no_rendezvous_barrier().

Reviewed by:	gnn, kib
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D10313
2017-04-09 02:00:03 +00:00
Andriy Gapon
35d92e6cec use msr 0xc001100c to discover multi-node AMD processors
This is applicable only to the older processors that do not have the AMD
Topology extension.
Opteron 6100-series "Magny-Cours" processors had multiple nodes within a
package and didn't have the Topology extension.  Without this change
FreeBSD would assume that those processors have a single L3 cache shared
by all cores while, in fact, each node has its own L3 cache.

Many thanks to Freddie Cash <fjwcash@gmail.com> for providing valuable
hardware information.

MFC after:	2 weeks
2017-04-08 14:16:42 +00:00
Andriy Gapon
978f3da16f revert r315959 because it causes build problems
The change introduced a dependency between genassym.c and header files
generated from .m files, but that dependency is not specified in the
make files.

Also, the change could be not as useful as I thought it was.

Reported by:	dchagin, Manfred Antar <null@pozo.com>, and many others
2017-03-27 12:34:29 +00:00
Andriy Gapon
80b9074a51 update comment describing topo_probe_amd()
MFC after:	2 weeks
MFC with:	r316017
2017-03-27 11:04:57 +00:00
Andriy Gapon
d9da46bf1c add SMT detection for newer AMD processors
The change seems to be more in the nomenclature than in the way the
topology is advertised by the hardware.

Tested by:	truckman (earlier version of the change)
MFC after:	2 weeks
2017-03-27 09:45:27 +00:00
Konstantin Belousov
476358b30f Timeout DMAR commands.
Implement timeouts for register-based DMAR commands.  Tunable/sysctl
hw.dmar.timeout specifies the timeout in nanoseconds, set it to zero
to allow infinite wait.  Default is 1ms.

Runtime modification of the sysctl is not safe, it is allowed for
debugging.

Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2017-03-27 07:06:45 +00:00
Konstantin Belousov
70fd237c5d Provide less laborius way to enable busdma DMAR to only short list of devices.
Kernel environment variable hw.busdma.default can take values 'bounce'
and 'dmar' and selects corresponding busdma backend as default.
Per-device environment variable hw.busdma.pci<domain>.<bus>.<slot>.<func>
takes the same values and overrides hw.busdma.default for the given device.

Note that even with hw.busdma.default=bounce, DMA translation engines
are still started if DMARs are enabled, to disable them use
hw.dmar.dma tunable, as before.

Sponsored by:	The FreeBSD Foundation
MFC after: 1 week
2017-03-26 00:40:35 +00:00
Andriy Gapon
a7b4c009e1 specific end of interrupt implementation for AMD Local APIC
The change is more intrusive than I would like because the feature
requires that a vector number is written to a special register.
Thus, now the vector number has to be provided to lapic_eoi().
It was readily available in the IO-APIC and MSI cases, but the IPI
handlers required more work.
Also, we now store the VMM IPI number in a global variable, so that it
is available to the justreturn handler for the same reason.

Reviewed by:	kib
MFC after:	6 weeks
Differential Revision: https://reviews.freebsd.org/D9880
2017-03-25 18:45:09 +00:00
Konstantin Belousov
3d47c58b98 Avoid leaking allocated but unused context after creation race.
As noted in the comment, nothing special needs to be done to destroy
the unneeded context after the allocation race, but the context memory
itself still should to be freed.

Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2017-03-25 10:47:35 +00:00
Konstantin Belousov
5f8e5c7fa2 Do not create RMRR entries for identity-mapped domains.
It does not make sense since identity mapping already provides the
required mapping for RMRR ranges.  More, since identity page tables do
not reflect content of map entries for id domains, creating RMRR
entries makes domain data inconsistent.

Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2017-03-25 10:45:16 +00:00
Konstantin Belousov
ad969cb1cd Slight cleanup of the comment.
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2017-03-25 10:42:10 +00:00
Gavin Atkinson
cb8f312598 Improve grammar on a warning, and only use one line rather than two when
printing it.
2017-03-24 16:18:20 +00:00
Roger Pau Monné
6e2ab0aef5 x86/srat: fix parsing of APIC IDs > MAX_APIC_ID
Ignore them like it's done in the MADT parser. This allows booting on a box
with SRAT and APIC IDs > 255.

Reported by:	Wei Liu <wei.liu2@citrix.com>
Tested by:	Wei Liu <wei.liu2@citrix.com>
Reviewed by:	kib
MFC after:	2 weeks
Sponsored by:	Citrix Systems R&D
2017-03-16 09:33:36 +00:00
Peter Grehan
264fae0792 Add the AMD MONITORX/MWAITX feature definition introduced in
Bulldozer/Ryzen CPUs.

Reviewed by:	kib
MFC after:	1 week
2017-03-16 03:06:50 +00:00
Eric van Gyzen
38ef0279a4 Validate values read from the RTC before trying BCD decoding
Submitted by:	cem
Reported by:	Michael Gmelin <freebsd@grem.de>
Tested by:	Oleksandr Tymoshenko <gonzo@bluezbox.com>
Sponsored by:	Dell EMC
2017-03-09 02:19:30 +00:00
Andriy Gapon
c1ad4beb32 mca: fix up couple of issues introduced with amd thresholding in r314636
1. There a was a typo in one place where the processor family is
   checked (16 vs 0x16).  Now the checks are consolidated in a single
   function.
2. Instead of an array of struct amd_et_state objects the code allocated
   an array of pointers.  That was no problem on amd64 where the sizes
   are the same, but could be a problem on i386.

Reported by:	tuexen and others
Tested by:	tuexen (earlier version of the fix)
Pointyhat to:	avg
MFC after:	5 days
X-MFC with:	r314636
2017-03-05 07:46:48 +00:00
Andriy Gapon
7abf460488 MCA: add AMD Error Thresholding support
Currently the feature is implemented only for a subset of errors
reported via Bank 4.  The subset includes only DRAM-related errors.

The new code builds upon and reuses the Intel CMC (Correctable MCE
Counters) support code.  However, the AMD feature is quite different
and, unfortunately, much less regular.

For references please see AMD BKDGs for models 10h - 16h.
Specifically, see MSR0000_0413 NB Machine Check Misc (Thresholding)
Register (MC4_MISC0).
http://developer.amd.com/resources/developer-guides-manuals/

Reviewed by:	jhb
MFC after:	1 month
Differential Revision: https://reviews.freebsd.org/D9613
2017-03-03 22:42:43 +00:00
Warner Losh
fbbd9655e5 Renumber copyright clause 4
Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.

Submitted by:	Jan Schaumann <jschauma@stevens.edu>
Pull Request:	https://github.com/freebsd/freebsd/pull/96
2017-02-28 23:42:47 +00:00
Andriy Gapon
bc1e649924 Local APIC: add support for extended LVT entries found in AMD processors
The extended LVT entries can be used to configure interrupt delivery
for various events that are internal to a processor and can use this
feature.

All current processors that support the feature have four of such entries.
The entries are all masked upon the processor reset, but it's possible
that firmware may use some of them.

BIOS and Kernel Developer's Guides for some processor models do not assign
any particular names to the extended LVTs, while other BKDGs provide names
and suggested usage for them.
However, there is no fixed mapping between the LVTs and the processor
events in any processor model that supports the feature.  Any entry can be
assigned to any event.  The assignment is done by programming an offset
of an entry into configuration bits corresponding to an event.

This change does not expose the flexibility that the feature offers.
The change adds just a single method to configure a hardcoded extended LVT
entry to deliver APIC_CMC_INT.  The method is designed to be used with
Machine Check Error Thresholding mechanism on supported processor models.

For references please see BKDGs for families 10h - 16h and specifically
descriptions of APIC30, APIC400, APIC[530:500] registers.
For a description of the Error Thresholding mechanism see, for example,
BKDG for family 10h, section 2.12.1.6.
http://developer.amd.com/resources/developer-guides-manuals/

Thanks to jhb and kib for their suggestions.

Reviewed by:	kib
Discussed with:	jhb
MFC after:	5 weeks
Relnotes:	maybe
Differential Revision: https://reviews.freebsd.org/D9612
2017-02-28 18:48:12 +00:00
Andriy Gapon
63509269e8 fix lvt_mode: edge-triggered interrupt mode is set by clearing APIC_LVT_TM
The fixed is used only to fix up buggy MPTable information and the
trigger mode is probably ignored for the relevant interrupt types
anyway.  Still, it's better to be standards compliant and have the code
do what it says it does.

Discussed with:	jhb
MFC after:	5 days
2017-02-27 17:36:31 +00:00
Yoshihiro Takahashi
645b154260 Fix the acpi idle support on i386 which was broken by r312910.
The ifdefs were '#if !defined(__i386__) || !defined(PC98)' previously,
so cpu_idle_acpi was enabled both i386 and amd64 except PC98.

I was obfuscated by '#if !defined(__i386__)' condition.

Submitted by:	bde
Reported by:	bde
2017-02-26 13:25:56 +00:00
Konstantin Belousov
d360b49b1d Do not use ULL suffix. Cast to uint64_t where the suffix is needed,
and just remove it in another place.

Requested by:	bde
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2017-02-25 10:32:49 +00:00
Warner Losh
28586889c2 Convert PCIe Hot Plug to using pci_request_feature
Convert PCIe hot plug support over to asking the firmware, if any, for
permission to use the HotPlug hardware. Implement pci_request_feature
for ACPI. All other host pci connections to allowing all valid feature
requests.

Sponsored by: Netflix
2017-02-25 06:11:59 +00:00
Jonathan T. Looney
a81ce6e9d5 We have seen several cases recently where we appear to get a double-fault:
We have an original panic. Then, instead of writing the core to the dump
device, the kernel has a second panic: "smp_targeted_tlb_shootdown:
interrupts disabled". This change is an attempt to fix that second panic.

When the other CPUs are stopped, we can't notify them of the TLB shootdown,
so we skip that operation. However, when the CPUs come back up, we
invalidate the TLB to ensure they correctly observe any changes to the
page mappings.

Reviewed by:	kib
Sponsored by:	Netflix
Differential Revision:	https://reviews.freebsd.org/D9786
2017-02-24 18:56:00 +00:00
Konstantin Belousov
8cd5962571 Remove cpu_deepest_sleep variable.
On Core2 and older Intel CPUs, where TSC stops in C2, system does not
allow C2 entrance if timecounter hardware is TSC.  This is done by
tc_windup() which tests for TC_FLAGS_C2STOP flag of the new
timecounter and increases cpu_disable_c2_sleep if flag is set.  Right
now init_TSC_tc() only sets the flag if cpu_deepest_sleep >= 2, but
TSC is initialized too early for this variable to be set by
acpi_cpu.c.

There is no reason to require that ACPI reported C2 and deeper states
to set TC_FLAGS_C2STOP, so remove cpu_deepest_sleep test from
init_TSC_tc() condition.  And since this is the only use of the
variable, remove it at all.

Reported and submitted by:	Jia-Shiun Li <jiashiun@gmail.com>
Suggested by:	jhb
MFC after:	2 weeks
2017-02-24 16:11:55 +00:00
Konstantin Belousov
091326f2ad More fixes for regression in r313898 on i386.
Use long long constants where needed.

Reported and tested by:	kargl
Sponsored by:	The FreeBSD Foundation
MFC after:	10 days
2017-02-22 07:07:05 +00:00
Andriy Gapon
b929de1078 mca: change type of last_intr to time_t for consinstency
time_uptime is time_t

MFC after:	1 day
X-MFC with:	r313752
2017-02-21 09:33:21 +00:00
Konstantin Belousov
8403b5a129 Fix regression in r313898 on i386.
Use large enough type for calculation of mtrr physmask.  Typical
cpu_maxphyaddr is 36 or larger.

Reported and tested by:	sbruno
Sponsored by:	The FreeBSD Foundation
MFC after:	13 days
2017-02-19 03:57:41 +00:00
Konstantin Belousov
83ebde953c Rely on CPUID feature only to enable attaching. MTRR are architectural
and there is no reason to check cpu family or vendor.

Noted by:   royger
Reviewed by: jhb
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
Differential revision:	https://reviews.freebsd.org/D9657
2017-02-17 22:50:41 +00:00
Konstantin Belousov
befb38bf9a smp_rendezvous() works for UP case as well, reduce duplicated
code.  Also fix cast and remove unneeded XXX in comment.

Noted and reviewed by: jhb
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
Differential revision:	https://reviews.freebsd.org/D9657
2017-02-17 22:49:52 +00:00
Konstantin Belousov
b1fa987835 Merge i386 and amd64 mtrr drivers.
Reviewed by:	royger, jhb
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
Differential revision:	https://reviews.freebsd.org/D9648
2017-02-17 21:08:32 +00:00
Warner Losh
86d99b6884 Remove EISA bus support for add-in cards. Remove related kernel and
compile options. Remove doxygen pointers to now deleted files. Remove
EISA and VME as examples in bus_space.9.

Retained EISA mode code for IO PIC and MPTABLES because that's not
EISA bus, per se, and some people have abused EISA to mean "EISA-like
behavior as opposed to ISA" rather than using it for EISA add-in
cards.

Relnotes: yes
2017-02-16 21:57:35 +00:00
Warner Losh
5625fe9246 Remove Micro Channel Architecture support. Of the commonly available
machines, only a few 486 machines that used it, and those haven't had
enough memory to run FreeBSD for quite some time (often limited to
16MB).

Not to be confused with the Machine Check Architecture, which is still
very much alive and used (and untouched by this commit).

No Objection From: arch@
2017-02-15 23:04:25 +00:00
Andriy Gapon
92b87cdb24 mca: use time_uptime instead of ticks for CMCI throttling
This solves several problems.
First of all, cmc_throttle is specified in seconds and there was no
conversion between ticks and seconds when they were mixed together.
Second, we avoid potential problems with ticks wrapping around.

Resolution of time_uptime should be sufficient for the throttling
purposes.

Discussed with:	jhb
MFC after:	12 days
2017-02-14 22:46:39 +00:00
Andriy Gapon
3be5c621e6 mca: fix writes to MSR_MC_CTL2 in cmci_update
Previously, if the threshold was changed, then MC_CTL2_CMCI_EN would get
cleared and the logic would switch to the polling only mode.

Discussed with:	jhb
MFC after:	2 weeks
2017-02-14 22:30:22 +00:00
Jonathan T. Looney
19d4720b1e Ensure the idle thread's loop services interrupts in a timely way when
using the ACPI C1/mwait sleep method.

Previously, the mwait instruction would return when an interrupt was
pending; however, the idle loop did not actually enable interrupts when
this occurred. This led to a situation where the idle loop could quickly
spin through the C1/mwait sleep method a number of times when an interrupt
was pending. (Eventually, the situation corrected itself when something
other than an interrupt triggered the idle loop to either enable interrupts
or schedule another thread.)

Reviewed by:	kib, imp (earlier version)
Input from:	jhb
MFC after:	1 week
Sponsored by:	Netflix
2017-02-08 16:46:57 +00:00
Konstantin Belousov
9fb10d635e Define the vm_ooffset_t and vm_pindex_t types as machine-independend.
The types are for the byte offset and page index in vm object.  They
are similar to off_t, which is defined as 64bit MI integer.  Using MI
definitions will allow to provide consistent MD values of vm
object-related maximum sizes.

Reviewed by:	alc
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2017-02-04 12:26:38 +00:00
Konstantin Belousov
57f6622f92 For i386, remove config options CPU_DISABLE_CMPXCHG, CPU_DISABLE_SSE
and device npx.

This means that FPU is always initialized and handled when available,
and SSE+ register file and exception are handled when available.  This
makes the kernel FPU code much easier to maintain by the cost of
slight bloat for CPUs older than 25 years.

CPU_DISABLE_CMPXCHG outlived its usefulness, see the removed comment
explaining the original purpose.

Suggested by and discussed with:	bde
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	3 weeks
2017-02-03 12:51:40 +00:00
Yoshihiro Takahashi
2b375b4edd Remove pc98 support completely.
I thank all developers and contributors for pc98.

Relnotes:	yes
2017-01-28 02:22:15 +00:00
Conrad Meyer
db4fcadf52 "Buses" is the preferred plural of "bus"
Replace archaic "busses" with modern form "buses."

Intentionally excluded:
* Old/random drivers I didn't recognize
  * Old hardware in general
* Use of "busses" in code as identifiers

No functional change.

http://grammarist.com/spelling/buses-busses/

PR:		216099
Reported by:	bltsrc at mail.ru
Sponsored by:	Dell EMC Isilon
2017-01-15 17:54:01 +00:00
Pedro F. Giffuni
be04edbb4f Remove __nonnull() attributes from x86 machine check architecture.
These are of the few cases where we use the GCC non-null attributes in
non-header code. As part of a review [1] of our use of such attributes we
are replacing such uses of the overly aggressive GCC attribute with clang's
_Nonnull attribute.

In this case the attributes serve little purpose as they just don't
enforce run time checks, If anything the attributes would cause NULL pointer
checks to be ignored but there are no such checks so only effect is
cosmetic.

The references appear to be left over from code development and likely
already fulfilled their purpose.

Reference [1]:
https://reviews.freebsd.org/D9004

Reviewed by:	jhb
MFC after:	3 weeks
2017-01-13 01:39:19 +00:00
Roger Pau Monné
ca7af67ac9 xen: fix IPI setup with EARLY_AP_STARTUP
Current Xen IPI setup functions require that the caller provide a device in
order to obtain the name of the interrupt from it. With early AP startup this
device is no longer available at the point where IPIs are bound, and a KASSERT
would trigger:

panic: NULL pcpu device_t
cpuid = 0
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xffffffff82233a20
vpanic() at vpanic+0x186/frame 0xffffffff82233aa0
kassert_panic() at kassert_panic+0x126/frame 0xffffffff82233b10
xen_setup_cpus() at xen_setup_cpus+0x5b/frame 0xffffffff82233b50
mi_startup() at mi_startup+0x118/frame 0xffffffff82233b70
btext() at btext+0x2c

Fix this by no longer requiring the presence of a device in order to bind IPIs,
and simply use the "cpuX" format where X is the CPU identifier in order to
describe the interrupt.

Reported by:            sbruno, cperciva
Tested by:              sbruno
X-MFC-With:             r310177
Sponsored by:           Citrix Systems R&D
2016-12-22 16:09:44 +00:00
Sepherosa Ziehau
fff5be0be3 hyperv: Implement userspace gettimeofday(2) with Hyper-V reference TSC
This 6 times gettimeofday performance, as measured by
tools/tools/syscall_timing

Reviewed by:	kib
MFC after:	1 week
Sponsored by:	Microsoft
Differential Revision:	https://reviews.freebsd.org/D8789
2016-12-19 07:40:45 +00:00
Mark Johnston
f85ea63d69 Don't run the MCA record refill task during boot.
The MCA taskqueue is not initialized until some time after CMCIs are
enabled on the BSP.

Reviewed by:	cem, jhb
MFC after:	1 week
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D8783
2016-12-14 19:00:08 +00:00
Konstantin Belousov
5ab0f0c3f0 Prefix hex memory addresses with 0x in diagnostic messages from the
SRAT parser.

Submitted by:	Oliver Pinter
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D8750
2016-12-11 19:01:27 +00:00
Mark Johnston
10c480e775 Require the STACK option for code that captures stacks of running threads.
stack_machdep.c is compiled if either of the DDB or STACK options is
specified, but stack_save_td_running() isn't useable from DDB. Moreover,
stack_save_td_running() works by raising an NMI on the CPU running the
target thread, and the corresponding handler is compiled only if STACK is
configured.

Reported by:	kib
MFC after:	1 week
2016-12-06 22:48:28 +00:00
Konstantin Belousov
3dd3c4503b Release DMAR table after using it.
Reported and tested by:	hps
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2016-12-05 11:42:09 +00:00
Konstantin Belousov
85d99487b8 Rename fast taskqueues used by DMAR to avoid naming conflict of the
sleepable and spin mutexes created by the queues.

Reported and tested by:	hps
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2016-12-05 11:41:09 +00:00
Alexey Dokuchaev
a48f5e1ffa - Mention mismatching numbers in MSR vs. ACPI _PSS count warning: seeing
actual numbers would help debugging (also, `MSR' and `ACPI' are standard
  abbreviations and thus should be properly capitalized)
- Rephrase unsupported AMD CPUs message and wrap as an overly long line:
  `sorry' 1) is wrongly spelled after period (starts with a small letter)
  and 2) carries emotional "tinge" that is unnecessary and even bogus in
  debug message; `implemented' is not the best word as `supported' suits
  better in this context
- Improve readability when reporting resulted P-state transition (debug)

Approved by:	jhb
2016-12-01 14:31:05 +00:00
Konstantin Belousov
83a288f434 Fix automatic eventtimer hardware selection when ARAT
(APIC-Timer-always-running) is not implemented.

If machine has ncpus >= 8 and non-FSB interrupt routing from HPET,
default HPET eventtimer quality 450 is reduced by 100, i.e. it is
350. On the other hand, LAPIC default quality is 600 and it is reduced
by 200 if ARAT is not reported. We end up with HPET quality 350 <
LAPIC quality 400, despite ARAT is not set.  Then, since deep Cx
states are active by default, eventtimer fail.

E.g., on Nehalem Core i7 CPU and X58 chipset, LAPIC only works in
C0/C1/C1E and HPET does not implement FSB mode, which otherwise
requires manual switch to HPET to get working system.

Set LAPIC eventtimer quality to 100 if no ARAT.
While there, do not ignore deadlint TSC mode for LAPIC timer if ARAT
is not implemented.  If user manually selected LAPIC eventtimer on
such CPU, there is no reason to not use deadline if available and not
disabled administratively.

Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2016-11-26 10:33:53 +00:00
Bryan Drewery
28323add09 Fix improper use of "its".
Sponsored by:	Dell EMC Isilon
2016-11-08 23:59:41 +00:00
Adrian Chadd
7cfecbb95b Add a witness check to enforce that no non-sleeping locks are held when
they shouldn't be.

I used this during driver bring-up to find that the Linux driver holds a
whole lot of locks whilst doing their equivalent of busdma operations.

If this works out well, it should be added to the other architecture busdma
implementations to aid in similar debugging.

Tested:

* bounce buffer and dmar busdma, Lenovo X230 laptop, all the internal
  hardware
* ath(4) too

Discussed with: jhb
2016-11-03 23:11:33 +00:00
Roger Pau Monné
0f4d7d9fd7 xen/intr: add reference counts to event channels
Add a reference count to xenisrc. This is required for implementation of
unmap-notifications in the grant table userspace device (gntdev). We need to
hold a reference to the event channel port, in case the user deallocates the
port before we send the notification.

Submitted by:		jaggi
Reviewed by:		royger
Differential review:	https://reviews.freebsd.org/D7429
2016-10-31 13:00:53 +00:00
Konstantin Belousov
1d6dfd1230 Use correct cpu id in the banner. Fix style.
Noted by:	avg
Sponsored by:	The FreeBSD Foundation
MFC after:	9 days
2016-10-28 12:27:05 +00:00
John Baldwin
7b64a80b55 Add powerd(8) support for several families of AMD CPUs.
Use the same logic to calculate the nominal CPU frequency from the P-state
MSRs on family 0x12, 0x15, and 0x16 CPUs as is used for family 0x10.
Family 0x14 was included in the original patch in the PR but I left that
out as the BIOS writer's guide for family 0x14 CPUs show a different layout
for the relevant MSR and include a different formulate for calculating the
frequency.

While here, simplify a few expressions and print out the family of
unsupported CPUs in hex rather than decimal.

PR:		212020
Submitted by:	Anthony Jenkins <Scoobi_doo@yahoo.com>
MFC after:	1 month
Differential Revision:	https://reviews.freebsd.org/D7587
2016-10-27 21:31:56 +00:00
John Baldwin
16dcd7734f MFamd64: Add bounds checks on addresses used with /dev/mem.
Reject attempts to read from or memory map offsets in /dev/mem that are
beyond the maximum-supported physical address of the current CPU.

Reviewed by:	kib
MFC after:	1 month
Differential Revision:	https://reviews.freebsd.org/D7408
2016-10-27 21:23:14 +00:00
Konstantin Belousov
295f4b6cfe Follow-up to r307866:
- Make !KDB config buildable.
- Simplify interface to nmi_handle_intr() by evaluating panic_on_nmi
  in one place, namely nmi_call_kdb().  This allows to remove do_panic
  argument from the functions, and to remove i386/amd64 duplication of
  the variable and sysctl definitions.  Note that now NMI causes
  panic(9) instead of trap_fatal() reporting and then panic(9),
  consistently for NMIs delivered while CPU operated in ring 0 and 3.

Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2016-10-24 20:47:46 +00:00
Konstantin Belousov
a57d70325e Fix typo.
Submitted by:	alc
MFC after:	3 days
2016-10-24 17:37:21 +00:00
Konstantin Belousov
835c2787be Handle broadcast NMIs.
On several Intel chipsets, diagnostic NMIs sent from BMC or NMIs
reporting hardware errors are broadcasted to all CPUs.

When kernel is configured to enter kdb on NMI, the outcome is
problematic, because each CPU tries to enter kdb.  All CPUs are
executing NMI handlers, which set the latches disabling the nested NMI
delivery; this means that stop_cpus_hard(), used by kdb_enter() to
stop other cpus by broadcasting IPI_STOP_HARD NMI, cannot work.  One
indication of this is the harmless but annoying diagnostic "timeout
stopping cpus".

Much more harming behaviour is that because all CPUs try to enter kdb,
and if ddb is used as debugger, all CPUs issue prompt on console and
race for the input, not to mention the simultaneous use of the ddb
shared state.

Try to fix this by introducing a pseudo-lock for simultaneous attempts
to handle NMIs.  If one core happens to enter NMI trap handler, other
cores see it and simulate reception of the IPI_STOP_HARD.  More,
generic_stop_cpus() avoids sending IPI_STOP_HARD and avoids waiting
for the acknowledgement, relying on the nmi handler on other cores
suspending and then restarting the CPU.

Since it is impossible to detect at runtime whether some stray NMI is
broadcast or unicast, add a knob for administrator (really developer)
to configure debugging NMI handling mode.

The updated patch was debugged with the help from Andrey Gapon (avg)
and discussed with him.

Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
Differential revision:	https://reviews.freebsd.org/D8249
2016-10-24 16:40:27 +00:00
Mateusz Guzik
53dc58f2dc Mark a bunch of mpsafe sysctls as such.
This gives me a sysctl Giant-free buildworld.
2016-10-19 19:42:01 +00:00
John Baldwin
4fae28a084 Reprogram I/O APIC interrupt pins when registering an I/O APIC.
All I/O APIC pins are masked when an I/O APIC is first probed.  The
APIC enumerator (MP Table or MADT) then parses its associated tables to
configure individual pins to set custom delivery modes or alternate
routing (e.g. routing IRQ 0 to intpin 2).  Pins for regular interrupt
pins are left masked until the first interrupt is assigned.  However,
pins with unusual settings (e.g. NMI or SMI) are never assigned an
interrupt and thus never re-programmed.  The I/O APIC code used to
reprogram all interrupt pins during registration but this was lost in
r151979.

In theory, this is mostly a no-op as the ACPI APIC table does not
include a way to enumerate NMI or SMI pins for the I/O APIC, so only
systems using an MP Table would be affected.

Reported by:	avg
MFC after:	1 month
2016-10-14 21:51:50 +00:00
Jung-uk Kim
493deb390b Merge ACPICA 20160930. 2016-10-04 20:27:15 +00:00
Konstantin Belousov
83c001d3c2 Re-apply r306516 (by cem):
Reduce the cost of TLB invalidation on x86 by using per-CPU completion flags

Reduce contention during TLB invalidation operations by using a per-CPU
completion flag, rather than a single atomically-updated variable.

On a Westmere system (2 sockets x 4 cores x 1 threads), dtrace measurements
show that smp_tlb_shootdown is about 50% faster with this patch; observations
with VTune show that the percentage of time spent in invlrng_single_page on an
interrupt (actually doing invalidation, rather than synchronization) increases
from 31% with the old mechanism to 71% with the new one.  (Running a basic file
server workload.)

Submitted by:	Anton Rang <rang at acm.org>
Reviewed by:	cem (earlier version)
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D8041
2016-10-04 17:01:24 +00:00
Conrad Meyer
31f575777c Revert r306516 for now, it is incomplete on i386
Noted by:	kib
2016-09-30 18:58:50 +00:00
Conrad Meyer
2965d505f6 Reduce the cost of TLB invalidation on x86 by using per-CPU completion flags
Reduce contention during TLB invalidation operations by using a per-CPU
completion flag, rather than a single atomically-updated variable.

On a Westmere system (2 sockets x 4 cores x 1 threads), dtrace measurements
show that smp_tlb_shootdown is about 50% faster with this patch; observations
with VTune show that the percentage of time spent in invlrng_single_page on an
interrupt (actually doing invalidation, rather than synchronization) increases
from 31% with the old mechanism to 71% with the new one.  (Running a basic file
server workload.)

Submitted by:	Anton Rang <rang at acm.org>
Reviewed by:	cem (earlier version), kib
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D8041
2016-09-30 18:12:16 +00:00
Sepherosa Ziehau
37e0abf2ef x86/ioapic: Fix destination cpu for Hyper-V
On Hyper-V:
- Stick to the first cpu for all I/O APIC pins.
- And don't allow destination cpu changes.

Reviewed by:	jhb
MFC after:	1 week
Sponsored by:	Microsoft
Differential Revision:	https://reviews.freebsd.org/D7949
2016-09-30 06:08:21 +00:00
Konstantin Belousov
36596c2a29 Detect x2APIC mode on boot and obey it.
If BIOS performed hand-off to OS with BSP LAPIC in the x2APIC mode,
system usually consumes such configuration without a notice, since
x2APIC is turned on by OS if possible (nop).  But if BIOS
simultaneously requested OS to not use x2APIC, code assumption that
that xAPIC is active breaks.

In my opinion, we cannot safely turn off x2APIC if control is passed
in this mode.  Make madt.c ignore user or BIOS requests to turn x2APIC
off, and do not check the x2APIC black list.  Just trust the config
and try to continue, giving a warning in dmesg.

Reported and tested by:	Slawa Olhovchenkov <slw@zxy.spb.ru> (previous version)
Diagnosed by and discussed with:	avg
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2016-09-19 15:58:45 +00:00
Bruce Evans
5904b5a6f2 Fix decoding of tf_rsp on amd64, and move TF_HAS_STACKREGS() to the
i386-only section, and fix a comment about the amd64 kernel trapframe
not having stackregs.

tf_rsp doesn't need decoding on amd64, but had an old clone of i386
code to do this in 1 place, and since the amd64 kernel trapframe does
have stackregs, the result was an off-by-16 error for %rsp in an error
message.
2016-09-16 07:09:35 +00:00
John Baldwin
38605d7312 Remove 'cpu' and 'cpu_class' on amd64.
The 'cpu' and 'cpu_class' variables were always set to the same value
on amd64 and are legacy holdovers from i386.  Remove them entirely on
amd64.

Reviewed by:	imp, kib (older version)
Differential Revision:	https://reviews.freebsd.org/D7888
2016-09-15 17:05:54 +00:00
Bruce Evans
701ac88055 Use the MI macro TRAPF_USERMODE() instead of open-coded checks for
SEL_UPL and sometimes PSL_VM.  This is just a style change on amd64,
but on i386 it fixes 1 unimportant place where the PSL_VM check was
missing and starts fixing 1 important place where the PSL_VM check
had a logic error.

Fix logic errors in treating vm86 bioscall mode as kernel mode.  The
main place checked all the necessary flags, but put the necessary
parentheses for the PSL_VM and PCB_VM86CALL checks in the wrong
place.  The broken case is only reached if a vm86 bioscall uses a
%cs which is nonzero mod 4, but that is unusual -- most bios calls
start with %cs = 0xc000 or 0xf000 and rarely change it.  Another
place was missing the check for PCB_VM86CALL, but was only reachable
if there are bugs virtualizing PSL_I.

Add a macro TF_HAS_STACKREGS() and use this instead of converting
open-coded checks of SEL_UPL, etc. to TRAPF_USERMODE() when we only
care about whether the frame has stack registers.  This fixes 3
places in my recent fix for register variables in vm86 mode where I
messed up the PSL_VM check and cleans up other places.
2016-09-14 12:57:40 +00:00
Konstantin Belousov
1a9ded46bd Fix typo in comment.
MFC after:	3 days
2016-09-12 16:44:21 +00:00
Sepherosa Ziehau
b9f62e3a74 x86: Use sx lock for interrupt sources.
- Certain pic_assign_cpu, e.g. msi_assign_cpu can have quite a long
  call chain.  For msi_assign_cpu, mutex makes complex PCI bridge
  drivers more tricky, e.g. sleep can note be called, etc, it will
  be pretty tricky for upcoming Hyper-V PCI bridge driver for PCI
  pass-through.
- It is not used on any hot code path nor non-sleepable context, so
  sx should have the same effect as mutex.

PIC list is still protected by mutex to keep suspend/resume work.

Discussed with: jhb
Reviewed by:	jhb
MFC after:	3 weeks
Sponsored by:	Microsoft
Differential Revision:	https://reviews.freebsd.org/D7784
2016-09-12 04:57:58 +00:00
John Baldwin
db4b3cdad8 Remove remnants of PERFMON and I586_PMC_GUPROF from amd64.
These options were never fully ported over from i386.
2016-09-06 19:25:32 +00:00
John Baldwin
a47632d45b Fix build for !SMP kernels after the Xen MSIX workaround.
Move msix_disable_migration under #ifdef SMP since it doesn't make sense
for !SMP kernels.

PR:		212014
Reported by:	Glyn Grinstead <glyn@grinstead.org>
MFC after:	3 days
2016-08-22 21:23:17 +00:00
Konstantin Belousov
1680854946 Implement userspace gettimeofday(2) with HPET timecounter.
Right now, userspace (fast) gettimeofday(2) on x86 only works for
RDTSC.  For older machines, like Core2, where RDTSC is not C2/C3
invariant, and which fall to HPET hardware, this means that the call
has both the penalty of the syscall and of the uncached hw behind the
QPI or PCIe connection to the sought bridge.  Nothing can me done
against the access latency, but the syscall overhead can be removed.
System already provides mappable /dev/hpetX devices, which gives
straight access to the HPET registers page.

Add yet another algorithm to the x86 'vdso' timehands. Libc is updated
to handle both RDTSC and HPET.  For HPET, the index of the hpet device
to mmap is passed from kernel to userspace, index might be changed and
libc invalidates its mapping as needed.

Remove cpu_fill_vdso_timehands() KPI, instead require that
timecounters which can be used from userspace, to provide
tc_fill_vdso_timehands{,32}() methods.  Merge i386 and amd64
libc/<arch>/sys/__vdso_gettc.c into one source file in the new
libc/x86/sys location.  __vdso_gettc() internal interface is changed
to move timecounter algorithm detection into the MD code.

Measurements show that RDTSC even with the syscall overhead is faster
than userspace HPET access.  But still, userspace HPET is three-four
times faster than syscall HPET on several Core2 and SandyBridge
machines.

Tested by:	Howard Su <howard0su@gmail.com>
Sponsored by:	The FreeBSD Foundation
MFC after:	1 month
Differential revision:	https://reviews.freebsd.org/D7473
2016-08-17 09:52:09 +00:00
Pedro F. Giffuni
a061aa46fe sys: replace comma with semicolon when pertinent.
Uses of commas instead of a semicolons can easily go undetected. The comma
can serve as a statement separator but this shouldn't be abused when
statements are meant to be standalone.

Detected with devel/coccinelle following a hint from DragonFlyBSD.

MFC after:	1 month
2016-08-09 19:42:20 +00:00
John Baldwin
264cd10809 Add additional constants.
- Add constants for the fields in the root-entry table address register,
  namely the root type type (RTT) and root table address (RTA) mask.
- Add macros for the bitmask of the domain ID field in the second word
  of context table entries as well as a helper macro (DMAR_CTX2_GET_DID)
  to extract the domain ID from a context table entry.

Reviewed by:	kib
MFC after:	1 month
Sponsored by:	Chelsio Communications
2016-08-09 19:02:14 +00:00
John Baldwin
f454e7ebf5 Add __printflike() to bus_describe_intr() to enable -Wformat checks.
Fix a few places that were passing a raw string as the format to use
a "%s" format string instead.

MFC after:	2 months
2016-08-04 18:29:16 +00:00
Konstantin Belousov
fa03524a9f Merge i386 and amd64 variants of mp_watchdog.c into x86/, there is no
difference between files.
For pc98, put x86/mp_x86.c into the same place as used by i386 file list.
Fix typo in comment.

Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2016-08-03 13:51:53 +00:00
Roger Pau Monné
23006680c7 Revert r291022: x86/intr: allow mutex recursion in intr_remove_handler
This was only needed for Xen, and a better way to deal with this issue has
been found, so this commit can be reverted.

Sponsored by:		Citrix Systems R&D
MFC after:		5 days
Reviewed by:		kib
Differential revision:	https://reviews.freebsd.org/D7363
2016-07-29 16:35:58 +00:00
Roger Pau Monné
35fdb32d86 xen-intr: fix removal of event channels during resume
Event channel handlers cannot be removed during resume because there might
be an interrupt thread running on a CPU currently blocked in the
cpususpend_handler, which prevents the call to intr_remove_handler from
finishing and completely freezes the system during resume. r291022 tried to
fix this by allowing recursion in intr_remove_handler, but that's clearly
not enough.

Instead don't remove the handlers at the interrupt resume phase, and let
each driver remove the handler by itself during resume. In order to do this,
change the opaque event channel handler cookie to use the global interrupt
vector instead of the event channel port. The event channel port cannot be
used because after resume all event channels are reset, and the port numbers
can change.

Sponsored by:		Citrix Systems R&D
MFC after:		5 days
2016-07-29 16:34:54 +00:00
Maxim Sobolev
e0cd4b7f6f Don't print same value twice, one in decimal once in hex. This makes
output more cryptic than it needs to be and wastes cpu cycles and
console bandwidth.
2016-07-18 03:59:03 +00:00
Mark Johnston
f4d0e9c95f Allow ACPI wakeup code and page tables to be stored in non-contiguous pages.
Since these pages are allocated from a narrow range of memory, this makes
the allocation more likely to succeed.

Suggested by:	kib
Reviewed by:	jkim, kib
MFC after:	2 months
Differential Revision:	https://reviews.freebsd.org/D7154
2016-07-14 00:38:04 +00:00
Eric Badger
fdb6320d45 Add explicit detection of KVM hypervisor
Set vm_guest to a new enum value (VM_GUEST_KVM) when kvm is detected and use
vm_guest in conditionals testing for KVM.

Also, fix a conditional checking if we're running in a VM which caught only
the generic VM case, but not more specific VMs (KVM, VMWare, etc.).  (Spotted
by: vangyzen).

Differential revision:	https://reviews.freebsd.org/D7172
Sponsored by:	Dell Inc.
Approved by:	kib (mentor), vangyzen (mentor)
Reviewed by:	alc
MFC after:	4 weeks
2016-07-13 19:19:18 +00:00
Roger Pau Monné
302244700f xen: automatically disable MSI-X interrupt migration
If the hypervisor version is smaller than 4.6.0. Xen commits 74fd00 and
70a3cb are required on the hypervisor side for this to be fixed, and those
are only included in 4.6.0, so stay on the safe side and disable MSI-X
interrupt migration on anything older than 4.6.0.

It should not cause major performance degradation unless a lot of MSI-X
interrupts are allocated.

Sponsored by:		Citrix Systems R&D
MFC after:		3 days
Reviewed by:		jhb
Differential revision:	https://reviews.freebsd.org/D7148
2016-07-12 08:43:09 +00:00
John Baldwin
be0319fd19 Add a tunable to disable migration of MSI-X interrupts.
The new 'machdep.disable_msix_migration' tunable can be set to 1 to
disable migration of MSI-X interrupts.

Xen versions prior to 4.6.0 do not properly handle updates to MSI-X
table entries after the initial write.  In particular, the operation
to unmask a table entry after updating it during migration is not
propagated to the "real" table for passthrough devices causing the
interrupt to remain masked.  At least some systems in EC2 are
affected by this bug when using SRIOV.  The tunable can be set in
loader.conf as a workaround.

Submitted by:	Jeremiah Lott <jlott@averesystems.com> (original patch)
Approved by:	re (marius)
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D6947
2016-06-24 22:49:32 +00:00
Mark Johnston
c722a89a63 Use M_NOWAIT when allocating memory for the ACPI wakeup handler.
If the allocation attempt fails, we may otherwise VM_WAIT after a failed
attempt to reclaim contiguous memory in the requested range. After r297466,
this results in the thread going to sleep, causing a hang during boot.

Reviewed by:	jkim, kib
Approved by:	re (gjb)
Sponsored by:	EMC / Isilon Storage Division
Differential Revision:	https://reviews.freebsd.org/D6945
2016-06-23 19:24:38 +00:00
Konstantin Belousov
0bf716e988 Trim some spaces to record correct commit message for the r301278.
Reduce number of iterations used for calibrating ICR read loop.  The
new number of iteration still gives the same ICR latency as before,
tested on Intel SandyBridge and Haswell machines, and on AMD.  But it
significantly reduces the unneeded pause on boot in some VMs, from ~10
secs to less then 1 sec.  It was reported to occur in bhyve on AMD
host.

Reported and tested by:	avg
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2016-06-03 18:23:45 +00:00
Konstantin Belousov
fcc1d8c9eb diff --git a/sys/x86/x86/local_apic.c b/sys/x86/x86/local_apic.c
index d8bda77..bb15df0 100644
--- a/sys/x86/x86/local_apic.c
+++ b/sys/x86/x86/local_apic.c
@@ -511,7 +511,7 @@ native_lapic_init(vm_paddr_t addr)
 	}

 #ifdef SMP
-#define	LOOPS	1000000
+#define	LOOPS	100000
 	/*
 	 * Calibrate the busy loop waiting for IPI ack in xAPIC mode.
 	 * lapic_ipi_wait_mult contains the number of iterations which
2016-06-03 18:05:18 +00:00
Ed Schouten
3a45c3d643 Implement _ALIGN() using internal integer types.
The existing version depends on register_t and uintptr_t, which are only
available when including headers such as <sys/types.h>. As this macro is
used by <sys/socket.h>, for example, it should be written in such a way
that it doesn't depend on those types.
2016-05-31 13:31:19 +00:00
Ed Schouten
78fe75bc28 Add missing dependency on <machine/_limits.h>.
In r227474, this header file was changed to define SIG_ATOMIC_{MIN,MAX}
in terms of LONG_{MIN,MAX}. Unlike all of the definitions in this header
file, LONG_{MIN,MAX} is provided by <limits.h>. Remove the dependency on
<limits.h> by using __LONG_{MIN,MAX} instead and including
<machine/_limits.h>.

This change is needed to make SIG_ATOMIC_{MIN,MAX} work without
including any other header files.
2016-05-31 08:38:24 +00:00
Ed Schouten
46f38226d7 Add missing dependency on <machine/_limits.h>.
This header uses __INT_MIN and __INT_MAX, which is provided by
<machine/_limits.h>. This is needed to make <stdint.h>'s WCHAR_MIN and
WCHAR_MAX work without including other headers as well.
2016-05-31 08:36:39 +00:00
Sepherosa Ziehau
98a68947d4 hyperv/vmbus: Rename ISR functions
MFC after:	1 week
Sponsored by:	Microsoft OSTC
Differential Revision:	https://reviews.freebsd.org/D6601
2016-05-31 04:47:53 +00:00
Konstantin Belousov
f159d7d6f0 Only calibrate ICR read loop when not in x2APIC mode. Run-time
switching between LAPIC modes is not supported, and there is no need
to wait for IPI ack in x2APIC mode.  So the calibrated delay is only
needed for !x2APIC.

This saves around a second of boot time on the real hardware for
x2APIC.

Sponsored by:	The FreeBSD Foundation
2016-05-26 09:09:11 +00:00
John Baldwin
10544b0951 Implement support for RF_UNMAPPED and bus_map/unmap_resource on x86.
Add implementations of bus_map/unmap_resource to the x86 nexus driver.
Change bus_activate/deactivate_resource to honor RF_UNMAPPED and to
use bus_map/unmap_resource to create/destroy the implicit mapping when
RF_UNMAPPED is not set.

Reviewed by:	cem
Differential Revision:	https://reviews.freebsd.org/D5237
2016-05-20 18:00:10 +00:00
John Baldwin
fdce57a042 Add an EARLY_AP_STARTUP option to start APs earlier during boot.
Currently, Application Processors (non-boot CPUs) are started by
MD code at SI_SUB_CPU, but they are kept waiting in a "pen" until
SI_SUB_SMP at which point they are released to run kernel threads.
SI_SUB_SMP is one of the last SYSINIT levels, so APs don't enter
the scheduler and start running threads until fairly late in the
boot.

This change moves SI_SUB_SMP up to just before software interrupt
threads are created allowing the APs to start executing kernel
threads much sooner (before any devices are probed).  This allows
several initialization routines that need to perform initialization
on all CPUs to now perform that initialization in one step rather
than having to defer the AP initialization to a second SYSINIT run
at SI_SUB_SMP.  It also permits all CPUs to be available for
handling interrupts before any devices are probed.

This last feature fixes a problem on with interrupt vector exhaustion.
Specifically, in the old model all device interrupts were routed
onto the boot CPU during boot.  Later after the APs were released at
SI_SUB_SMP, interrupts were redistributed across all CPUs.

However, several drivers for multiqueue hardware allocate N interrupts
per CPU in the system.  In a system with many CPUs, just a few drivers
doing this could exhaust the available pool of interrupt vectors on
the boot CPU as each driver was allocating N * mp_ncpu vectors on the
boot CPU.  Now, drivers will allocate interrupts on their desired CPUs
during boot meaning that only N interrupts are allocated from the boot
CPU instead of N * mp_ncpu.

Some other bits of code can also be simplified as smp_started is
now true much earlier and will now always be true for these bits of
code.  This removes the need to treat the single-CPU boot environment
as a special case.

As a transition aid, the new behavior is available under a new kernel
option (EARLY_AP_STARTUP).  This will allow the option to be turned off
if need be during initial testing.  I plan to enable this on x86 by
default in a followup commit in the next few days and to have all
platforms moved over before 11.0.  Once the transition is complete,
the option will be removed along with the !EARLY_AP_STARTUP code.

These changes have only been tested on x86.  Other platform maintainers
are encouraged to port their architectures over as well.  The main
things to check for are any uses of smp_started in MD code that can be
simplified and SI_SUB_SMP SYSINITs in MD code that can be removed in
the EARLY_AP_STARTUP case (e.g. the interrupt shuffling).

PR:		kern/199321
Reviewed by:	markj, gnn, kib
Sponsored by:	Netflix
2016-05-14 18:22:52 +00:00