Commit Graph

38 Commits

Author SHA1 Message Date
Alexander Motin
a157e42516 Refactor timer management code with priority to one-shot operation mode.
The main goal of this is to generate timer interrupts only when there is
some work to do. When CPU is busy interrupts are generating at full rate
of hz + stathz to fullfill scheduler and timekeeping requirements. But
when CPU is idle, only minimum set of interrupts (down to 8 interrupts per
second per CPU now), needed to handle scheduled callouts is executed.
This allows significantly increase idle CPU sleep time, increasing effect
of static power-saving technologies. Also it should reduce host CPU load
on virtualized systems, when guest system is idle.

There is set of tunables, also available as writable sysctls, allowing to
control wanted event timer subsystem behavior:
  kern.eventtimer.timer - allows to choose event timer hardware to use.
On x86 there is up to 4 different kinds of timers. Depending on whether
chosen timer is per-CPU, behavior of other options slightly differs.
  kern.eventtimer.periodic - allows to choose periodic and one-shot
operation mode. In periodic mode, current timer hardware taken as the only
source of time for time events. This mode is quite alike to previous kernel
behavior. One-shot mode instead uses currently selected time counter
hardware to schedule all needed events one by one and program timer to
generate interrupt exactly in specified time. Default value depends of
chosen timer capabilities, but one-shot mode is preferred, until other is
forced by user or hardware.
  kern.eventtimer.singlemul - in periodic mode specifies how much times
higher timer frequency should be, to not strictly alias hardclock() and
statclock() events. Default values are 2 and 4, but could be reduced to 1
if extra interrupts are unwanted.
  kern.eventtimer.idletick - makes each CPU to receive every timer interrupt
independently of whether they busy or not. By default this options is
disabled. If chosen timer is per-CPU and runs in periodic mode, this option
has no effect - all interrupts are generating.

As soon as this patch modifies cpu_idle() on some platforms, I have also
refactored one on x86. Now it makes use of MONITOR/MWAIT instrunctions
(if supported) under high sleep/wakeup rate, as fast alternative to other
methods. It allows SMP scheduler to wake up sleeping CPUs much faster
without using IPI, significantly increasing performance on some highly
task-switching loads.

Tested by:	many (on i386, amd64, sparc64 and powerc)
H/W donated by:	Gheorghe Ardelean
Sponsored by:	iXsystems, Inc.
2010-09-13 07:25:35 +00:00
Alexander Motin
875b8844be Implement new event timers infrastructure. It provides unified APIs for
writing event timer drivers, for choosing best possible drivers by machine
independent code and for operating them to supply kernel with hardclock(),
statclock() and profclock() events in unified fashion on various hardware.

Infrastructure provides support for both per-CPU (independent for every CPU
core) and global timers in periodic and one-shot modes. MI management code
at this moment uses only periodic mode, but one-shot mode use planned for
later, as part of tickless kernel project.

For this moment infrastructure used on i386 and amd64 architectures. Other
archs are welcome to follow, while their current operation should not be
affected.

This patch updates existing drivers (i8254, RTC and LAPIC) for the new
order, and adds event timers support into the HPET driver. These drivers
have different capabilities:
 LAPIC - per-CPU timer, supports periodic and one-shot operation, may
freeze in C3 state, calibrated on first use, so may be not exactly precise.
 HPET - depending on hardware can work as per-CPU or global, supports
periodic and one-shot operation, usually provides several event timers.
 i8254 - global, limited to periodic mode, because same hardware used also
as time counter.
 RTC - global, supports only periodic mode, set of frequencies in Hz
limited by powers of 2.

Depending on hardware capabilities, drivers preferred in following orders,
either LAPIC, HPETs, i8254, RTC or HPETs, LAPIC, i8254, RTC.
User may explicitly specify wanted timers via loader tunables or sysctls:
kern.eventtimer.timer1 and kern.eventtimer.timer2.
If requested driver is unavailable or unoperational, system will try to
replace it. If no more timers available or "NONE" specified for second,
system will operate using only one timer, multiplying it's frequency by few
times and uing respective dividers to honor hz, stathz and profhz values,
set during initial setup.
2010-06-20 21:33:29 +00:00
John Baldwin
58ccad7ddc Add support for corrected machine check interrupts. CMCI is a new local
APIC interrupt that fires when a threshold of corrected machine check
events is reached.  CMCI also includes a count of events when reporting
corrected errors in the bank's status register.  Note that individual
banks may or may not support CMCI.  If they do, each bank includes its own
threshold register that determines when the interrupt fires.  Currently
the code uses a very simple strategy where it doubles the threshold on
each interrupt until it succeeds in throttling the interrupt to occur
only once a minute (this interval can be tuned via sysctl).  The threshold
is also adjusted on each hourly poll which will lower the threshold once
events stop occurring.

Tested by:	Sailaja Bangaru  sbappana at yahoo com
MFC after:	1 month
2010-05-24 15:45:05 +00:00
Alexander Motin
dbd55f3ff0 - Implement MI helper functions, dividing one or two timer interrupts with
arbitrary frequencies into hardclock(), statclock() and profclock() calls.
Same code with minor variations duplicated several times over the tree for
different timer drivers and architectures.
- Switch all x86 archs to new functions, simplifying the code and removing
extra logic from timer drivers. Other archs are also welcome.
2010-05-24 11:40:49 +00:00
John Baldwin
90dfe31955 Add a handler for the local APIC error interrupt. For now it just prints
out the current value of the local APIC error register when the interrupt
fires.

MFC after:	1 week
2010-03-29 19:13:34 +00:00
Attilio Rao
306c0c6ea0 Improving the clocks auto-tunning by firstly checking if the atrtc may be
correctly initialized and just then assign to softclock/profclock.
Right now, some atrtc seems reporting strange diagnostic error* making the
current pattern bogus.

In order to do that cleanly, lapic_setup_clock(), on both ia32 and amd64,
now accepts as arguments the desired sources to handle, and returns the
actual ones (LAPIC_CLOCK_NONE is forbidden because otherwise there is no
meaning in calling such function).
This allows to bring out into commont x86 code the handling part for
machdep.lapic_allclocks tunable, which is retained.

Sponsored by:	Sandvine Incorporated
Tested by:	yongari, Richard Todd
		<rmtodd at ichotolot dot servalan dot com>
MFC:		3 weeks
X-MFC:		r202387, 204309
2010-03-03 17:13:29 +00:00
Attilio Rao
a26cb6d547 Handling all the three clocks (hardclock, softclock, profclock) with the
LAPIC may lead to aliasing for softclock and profclock because frequencies
are sized in order to fit mainly hardclock.
atrtc used to take care of the softclock and profclock and it does still
do, if the LAPIC can't handle the clocks properly.

Revert the change when the LAPIC started taking charge of all three of
them and let atrtc handle softclock and profclock if not explicitly
requested. Such request can be made setting != 0 the new tunable
machdep.lapic_allclocks or if the new device ATPIC is not present
within the i386 kernel config (atrtc is linked to atpic presence).

Diagnosed by:	Sandvine Incorporated
Reviewed by:	jhb, emaste
Sponsored by:	Sandvine Incorporated
MFC:		3 weeks
2010-01-15 16:04:30 +00:00
John Baldwin
21157ad3b1 Adjust the handling of the local APIC PMC interrupt vector:
- Provide lapic_disable_pmc(), lapic_enable_pmc(), and lapic_reenable_pmc()
  routines in the local APIC code that the hwpmc(4) driver can use to
  manage the local APIC PMC interrupt vector.
- Do not enable the local APIC PMC interrupt vector by default when
  HWPMC_HOOKS is enabled.  Instead, the hwpmc(4) driver explicitly
  enables the interrupt when it is succesfully initialized and disables
  the interrupt when it is unloaded.  This avoids enabling the interrupt
  on unsupported CPUs which may result in spurious NMIs.

Reported by:	rnoland
Reviewed by:	jkoshy
Approved by:	re (kib)
MFC after:	2 weeks
2009-08-14 21:05:08 +00:00
Attilio Rao
dc6fbf6545 * Completely Remove the option STOP_NMI from the kernel. This option
has proven to have a good effect when entering KDB by using a NMI,
but it completely violates all the good rules about interrupts
disabled while holding a spinlock in other occasions.  This can be the
cause of deadlocks on events where a normal IPI_STOP is expected.
* Adds an new IPI called IPI_STOP_HARD on all the supported architectures.
This IPI is responsible for sending a stop message among CPUs using a
privileged channel when disponible. In other cases it just does match a
normal IPI_STOP.
Right now the IPI_STOP_HARD functionality uses a NMI on ia32 and amd64
architectures, while on the other has a normal IPI_STOP effect. It is
responsibility of maintainers to eventually implement an hard stop
when necessary and possible.
* Use the new IPI facility in order to implement a new userend SMP kernel
function called stop_cpus_hard(). That is specular to stop_cpu() but
it does use the privileged channel for the stopping facility.
* Let KDB use the newly introduced function stop_cpus_hard() and leave
stop_cpus() for all the other cases
* Disable interrupts on CPU0 when starting the process of APs suspension.
* Style cleanup and comments adding

This patch should fix the reboot/shutdown deadlocks many users are
constantly reporting on mailing lists.

Please don't forget to update your config file with the STOP_NMI
option removal

Reviewed by:	jhb
Tested by:	pho, bz, rink
Approved by:	re (kib)
2009-08-13 17:09:45 +00:00
Alexander Motin
6a3a164d6e Add support for using i8254 and rtc timers as event sources for amd64 SMP
system. Redistribute hard-/stat-/profclock events to other CPUs using IPIs.
2009-05-02 12:20:43 +00:00
Jung-uk Kim
c66d2b38c8 Initial suspend/resume support for amd64.
This code is heavily inspired by Takanori Watanabe's experimental SMP patch
for i386 and large portion was shamelessly cut and pasted from Peter Wemm's
AP boot code.
2009-03-17 00:48:11 +00:00
Jeff Roberson
9c8e8e3aa7 - Allocate apic vectors on a per-cpu basis. This allows us to allocate
more irqs as we have more cpus.  This is principally useful on systems
   with msi devices which may want many irqs per-cpu.

Discussed with:	jhb
Sponsored by:	Nokia
2009-01-29 09:22:56 +00:00
John Baldwin
660f08b291 Add constants for fields in the local APIC error status register and a
routine to read it.
2008-12-11 15:56:30 +00:00
John Baldwin
2e025791ce Handle CPUs with APIC IDs higher than 32 (at least one IBM server uses
an APIC ID of 38 for its second CPU):
- Add a new MAX_APIC_ID constant for the highest valid APIC ID for modern
  systems.
- Size the various arrays in the MADT, MP Table, and SMP code that are
  indexed by APIC IDs to allow for up to MAX_APIC_ID.
- Explicitly go through and assign logical cpu ids to local APICs before
  starting any of the APs up rather than doing it while starting up the
  APs.  This step is now where we honor MAXCPU.

MFC after:	1 week
2007-05-08 22:01:04 +00:00
John Baldwin
fb610ca1f9 Minor fixes and tweaks to the x86 interrupt code:
- Split the intr_table_lock into an sx lock used for most things, and a
  spin lock to protect intrcnt_index.  Originally I had this as a spin lock
  so interrupt code could use it to lookup sources.  However, we don't
  actually do that because it would add a lot of overhead to interrupts,
  and if we ever do support removing interrupt sources, we can use other
  means to safely do so w/o locking in the interrupt handling code.
- Replace is_enabled (boolean) with is_handlers (a count of handlers) to
  determine if a source is enabled or not.  This allows us to notice when
  a source is no longer in use.  When that happens, we now invoke a new
  PIC method (pic_disable_intr()) to inform the PIC driver that the
  source is no longer in use.  The I/O APIC driver frees the APIC IDT
  vector when this happens.  The MSI driver no longer needs to have a
  hack to clear is_enabled during msi_alloc() and msix_alloc() as a result
  of this change as well.
- Add an apic_disable_vector() to reset an IDT vector back to Xrsvd to
  complement apic_enable_vector() and use it in the I/O APIC and MSI code
  when freeing an IDT vector.
- Add a new nexus hook: nexus_add_irq() to ask the nexus driver to add an
  IRQ to its irq_rman.  The MSI code uses this when it creates new
  interrupt sources to let the nexus know about newly valid IRQs.
  Previously the msi_alloc() and msix_alloc() passed some extra stuff
  back to the nexus methods which then added the IRQs.  This approach is
  a bit cleaner.
- Change the MSI sx lock to a mutex.  If we need to create new sources,
  drop the lock, create the required number of sources, then get the lock
  and try the allocation again.
2007-05-08 21:29:14 +00:00
John Baldwin
b8783b00f8 Add a new apic0 psuedo-device to claim memory resources for the memory
address ranges used by local and I/O APICs in the system.  Some systems
also reserve these ranges as system resources via either PnPBIOS or
ACPI, so this device currently attaches after acpi0 and legacy0 so that
the system resources are given precedence.
2007-03-20 21:53:31 +00:00
John Baldwin
aa7a005ee0 Use vm_paddr_t rather than uintptr_t when passing the physical address of
APICs to lapic_init() and ioapic_create().
2007-03-05 20:35:17 +00:00
Kip Macy
e5f8d4099d Newer versions of gcc don't support treating structures passed by value
as if they were really passed by reference. Specifically, the dead stores
elimination pass in the GCC 4.1 optimiser breaks the non-compliant behavior
on which FreeBSD relied. This change brings FreeBSD up to date by switching
trap frames to being explicitly passed by reference.

Reviewed by: kan
Tested by: kan
2006-12-17 06:48:40 +00:00
John Baldwin
4184900911 MD support for PCI Message Signalled Interrupts on amd64 and i386:
- Add a new apic_alloc_vectors() method to the local APIC support code
  to allocate N contiguous IDT vectors (aligned on a M >= N boundary).
  This function is used to allocate IDT vectors for a group of MSI
  messages.
- Add MSI and MSI-X PICs.  The PIC code here provides methods to manage
  edge-triggered MSI messages as x86 interrupt sources.  In addition to
  the PIC methods, msi.c also includes methods to allocate and release
  MSI and MSI-X messages.  For x86, we allow for up to 128 different
  MSI IRQs starting at IRQ 256 (IRQs 0-15 are reserved for ISA IRQs,
  16-254 for APIC PCI IRQs, and IRQ 255 is reserved).
- Add pcib_(alloc|release)_msi[x]() methods to the MD x86 PCI bridge
  drivers to bubble the request up to the nexus driver.
- Add pcib_(alloc|release)_msi[x]() methods to the x86 nexus drivers that
  ask the MSI PIC code to allocate resources and IDT vectors.

MFC after:	2 months
2006-11-13 22:23:34 +00:00
John Baldwin
520ffff83e Change the x86 interrupt code to suspend/resume interrupt controllers
(PICs) rather than interrupt sources.  This allows interrupt controllers
with no interrupt pics (such as the 8259As when APIC is in use) to
participate in suspend/resume.
- Always register the 8259A PICs even if we don't use any of their pins.
- Explicitly reset the 8259As on resume on amd64 if 'device atpic' isn't
  included.
- Add a "dummy" PIC for the local APIC on the BSP to reset the local APIC
  on resume.  This gets suspend/resume working with APIC on UP systems.
  SMP still needs more work to bring the APs back to life.

The MFC after is tentative.

Tested by:	anholt (i386)
Submitted by:	Andrea Bittau <a.bittau at cs.ucl.ac.uk> (3)
MFC after:	1 week
2006-10-10 23:23:12 +00:00
John Baldwin
4ac60df584 Add a new 'pmap_invalidate_cache()' to flush the CPU caches via the
wbinvd() instruction.  This includes a new IPI so that all CPU caches on
all CPUs are flushed for the SMP case.

MFC after:	1 month
2006-05-01 21:36:47 +00:00
John Baldwin
215e7c161a Rework how we wire up interrupt sources to CPUs:
- Throw out all of the logical APIC ID stuff.  The Intel docs are somewhat
  ambiguous, but it seems that the "flat" cluster model we are currently
  using is only supported on Pentium and P6 family CPUs.  The other
  "hierarchy" cluster model that is supported on all Intel CPUs with
  local APICs is severely underdocumented.  For example, it's not clear
  if the OS needs to glean the topology of the APIC hierarchy from
  somewhere (neither ACPI nor MP Table include it) and setup the logical
  clusters based on the physical hierarchy or not.  Not only that, but on
  certain Intel chipsets, even though there were 4 CPUs in a logical
  cluster, all the interrupts were only sent to one CPU anyway.
- We now bind interrupts to individual CPUs using physical addressing via
  the local APIC IDs.  This code has also moved out of the ioapic PIC
  driver and into the common interrupt source code so that it can be
  shared with MSI interrupt sources since MSI is addressed to APICs the
  same way that I/O APIC pins are.
- Interrupt source classes grow a new method pic_assign_cpu() to bind an
  interrupt source to a specific local APIC ID.
- The SMP code now tells the interrupt code which CPUs are avaiable to
  handle interrupts in a simpler and more intuitive manner.  For one thing,
  it means we could now choose to not route interrupts to HT cores if we
  wanted to (this code is currently in place in fact, but under an #if 0
  for now).
- For now we simply do static round-robin of IRQs to CPUs when the first
  interrupt handler just as before, with the change that IRQs are now
  bound to individual CPUs rather than groups of up to 4 CPUs.
- Because the IRQ to CPU mapping has now been moved up a layer, it would
  be easier to manage this mapping from higher levels.  For example, we
  could allow drivers to specify a CPU affinity map for their interrupts,
  or we could allow a userland tool to bind IRQs to specific CPUs.

The MFC is tentative, but I want to see if this fixes problems some folks
had with UP APIC kernels on 6.0 on SMP machines (an SMP kernel would work
fine, but a UP APIC kernel (such as GENERIC in RELENG_6) would lose
interrupts).

MFC after:	1 week
2006-02-28 22:24:55 +00:00
John Baldwin
b439e431bf Tweak how the MD code calls the fooclock() methods some. Instead of
passing a pointer to an opaque clockframe structure and requiring the
MD code to supply CLKF_FOO() macros to extract needed values out of the
opaque structure, just pass the needed values directly.  In practice this
means passing the pair (usermode, pc) to hardclock() and profclock() and
passing the boolean (usermode) to hardclock_cpu() and hardclock_process().
Other details:
- Axe clockframe and CLKF_FOO() macros on all architectures.  Basically,
  all the archs were taking a trapframe and converting it into a clockframe
  one way or another.  Now they can just extract the PC and usermode values
  directly out of the trapframe and pass it to fooclock().
- Renamed hardclock_process() to hardclock_cpu() as the latter is more
  accurate.
- On Alpha, we now run profclock() at hz (profhz == hz) rather than at
  the slower stathz.
- On Alpha, for the TurboLaser machines that don't have an 8254
  timecounter, call hardclock() directly.  This removes an extra
  conditional check from every clock interrupt on Alpha on the BSP.
  There is probably room for even further pruning here by changing Alpha
  to use the simplified timecounter we use on x86 with the lapic timer
  since we don't get interrupts from the 8254 on Alpha anyway.
- On x86, clkintr() shouldn't ever be called now unless using_lapic_timer
  is false, so add a KASSERT() to that affect and remove a condition
  to slightly optimize the non-lapic case.
- Change prototypeof  arm_handler_execute() so that it's first arg is a
  trapframe pointer rather than a void pointer for clarity.
- Use KCOUNT macro in profclock() to lookup the kernel profiling bucket.

Tested on:	alpha, amd64, arm, i386, ia64, sparc64
Reviewed by:	bde (mostly)
2005-12-22 22:16:09 +00:00
John Baldwin
333b8de537 MFi386:
- Move PUSH_FRAME and POP_FRAME to asmacros.h and use PUSH_FRAME in
  atpic entry points.
- Move PCPU_* asm macros out of the middle of the asm profiling macros.
- Pass IRQ vector argument as an int rather than void * to reduce diffs
  with i386.
- EOI the lapic in C for the lapic timer handler.
- GC unused Xcpuast function.
- Split IPI_STOP handling code of ipi_nmi_handler() out into a
  cpustop_handler() function and call it from Xcpustop rather than
  duplicating all the logic in assembly.
- Fixup the list of symbols with interrupt frames in ddb traces.
  Xatpic_fastintr* have never existed on amd64, and the lapic timer
  handler and various IPI handlers were missing.
- Use trapframe instead of intrframe for interrupt entry points (on amd64
  the interrupt vector was already a separate argument, so the two frames
  were already identical) and GC intrframe.

Submitted by:	peter (3)
2005-12-08 18:33:30 +00:00
John Baldwin
c7362ff7fb Change the x86 code to allocate IDT vectors on-demand when an interrupt
source is first enabled similar to how intr_event's now allocate ithreads
on-demand.  Previously, we would map IDT vectors 1:1 to IRQs.  Since we
only have 191 available IDT vectors for I/O interrupts, this limited us
to only supporting IRQs 0-190 corresponding to the first 190 I/O APIC
intpins.  On many machines, however, each PCI-X bus has its own APIC even
though it only has 1 or 2 devices, thus, we were reserving between 24 and
32 IRQs just for 1 or 2 devices and thus 24 or 32 IDT vectors.  With this
change, a machine with 100 IRQs but only 5 in use will only use up 5 IDT
vectors.  Also, this change provides an API (apic_alloc_vector() and
apic_free_vector()) that will allow a future MSI interrupt source driver to
request IDT vectors for use by MSI interrupts on x86 machines.

Tested on:	amd64, i386
2005-11-02 20:11:47 +00:00
Stephan Uphoff
6097174e4d Add IPI support for preempting a thread on another CPU.
MFC after:	3 weeks
2005-06-09 18:23:54 +00:00
Peter Wemm
ba5f6b61da MFi386: use the lapic timer for UP systems that are using the apic so that
IRQ0 and mixed mode isn't a problem anymore.  This removes mixed mode
support because nothing is left that uses it.
2005-04-15 18:44:53 +00:00
Peter Wemm
c29f1e2b3b MFi386: Bring over John's local apic timer code 2005-02-28 23:37:35 +00:00
Peter Wemm
b6e89c6d47 JumboMFi386: use bitmapped IPI handler. Update elcr and default mptable
config handler.  Tidy up various local apic initialization.
2005-01-21 06:01:20 +00:00
Peter Wemm
d8ad50b704 MFi386: various io apic cleanups 2004-07-08 01:42:49 +00:00
Peter Wemm
12c1418ccf Kill the LAZYPMAP ifdefs. While they worked, they didn't do anything
to help the AMD cpus (which have a hardware tlb flush filter).  I held
off to see what the 64 bit Intel cpus did, but it doesn't seem to help
much there either.  Oh well, store it in the Attic.
2004-05-16 22:11:50 +00:00
Peter Wemm
463e5aa66e MFi386: numerous interrupt and acpi updates 2004-05-16 20:30:47 +00:00
Peter Wemm
0d2a298904 Initial landing of SMP support for FreeBSD/amd64.
- This is heavily derived from John Baldwin's apic/pci cleanup on i386.
- I have completely rewritten or drastically cleaned up some other parts.
  (in particular, bootstrap)
- This is still a WIP.  It seems that there are some highly bogus bioses
  on nVidia nForce3-150 boards.  I can't stress how broken these boards
  are.  I have a workaround in mind, but right now the Asus SK8N is broken.
  The Gigabyte K8NPro (nVidia based) is also mind-numbingly hosed.
- Most of my testing has been with SCHED_ULE.  SCHED_4BSD works.
- the apic and acpi components are 'standard'.
- If you have an nVidia nForce3-150 board, you are stuck with 'device
  atpic' in addition, because they somehow managed to forget to connect the
  8254 timer to the apic, even though its in the same silicon!  ARGH!
  This directly violates the ACPI spec.
2003-11-17 08:58:16 +00:00
Peter Wemm
40e3826a9f Whitespace nit (sorry, couldn't help it) 2003-11-14 22:21:30 +00:00
John Baldwin
3ab2ba59f4 Shuffle the APIC interrupt vectors around a bit:
- Move the IPI and local APIC interrupt vectors up into the 0xf0 - 0xff
  range.  The pmap lazyfix IPI was reordered down next to the TLB
  shootdowns to avoid conflicting with the spurious interrupt vector.
- Move the base of APIC interrupts up 16 so that the first 16 APIC
  interrupts do not overlap the vectors used by the ATPIC.
- Remove bogus interrupt vector reservations for LINT[01].
- Now that 0xc0 - 0xef are available, use them for device interrupts.
  This increases the number of APIC device interrupts to 191.
- Increase the system-wide number of global interrupts to 191 to catch up
  to more APIC interrupts.

Requested by:	peter (2)
2003-11-14 19:10:13 +00:00
John Baldwin
69487322d8 Fix a typo. 2003-11-13 16:41:07 +00:00
John Baldwin
bd9cd7e3f7 - Move manipulation of td_intr_nesting_level out of assembly interrupt
vector stubs and into the C functions they call.
- Move disabling and EOIing of interrupt sources out of PIC driver entry
  points and into intr_execute_handlers().  Intr_execute_handlers() only
  disables a source for an interrupt if it is a stray interrupt or has
  threaded handlers.  Sources with fast handlers no longer disable (mask)
  the source while executing the handlers.
- Move the setting of clkintr_pending into intr_execute_handlers() and set
  the variable for any interrupt source with a vector of 0.  (Should only
  be true for IRQ 0.)  This fixes clkintr_pending in the NO_MIXED_MODE
  case.
- Implement lapic_eoi() and use it to implement ioapic_eoi_source().
- Rename atpic_sched_ithd() to atpic_handle_intr() since it is used to
  handle all atpic interrupts and not just threaded ones.

Inspired by:	peter's changes to amd64 in p4 (1)
Requested by:	bde (2)
2003-11-12 18:13:57 +00:00
John Baldwin
6f92bdd0c1 New APIC support code:
- The apic interrupt entry points have been rewritten so that each entry
  point can serve 32 different vectors.  When the entry is executed, it
  uses one of the 32-bit ISR registers to determine which vector in its
  assigned range was triggered.  Thus, the apic code can support 159
  different interrupt vectors with only 5 entry points.
- We now always to disable the local APIC to work around an errata in
  certain PPros and then re-enable it again if we decide to use the APICs
  to route interrupts.
- We no longer map IO APICs or local APICs using special page table
  entries.  Instead, we just use pmap_mapdev().  We also no longer
  export the virtual address of the local APIC as a global symbol to
  the rest of the system, but only in local_apic.c.  To aid this, the
  APIC ID of each CPU is exported as a per-CPU variable.
- Interrupt sources are provided for each intpin on each IO APIC.
  Currently, each source is given a unique interrupt vector meaning that
  PCI interrupts are not shared on most machines with an I/O APIC.
  That mapping for interrupt sources to interrupt vectors is up to the
  APIC enumerator driver however.
- We no longer probe to see if we need to use mixed mode to route IRQ 0,
  instead we always use mixed mode to route IRQ 0 for now.  This can be
  disabled via the 'NO_MIXED_MODE' kernel option.
- The npx(4) driver now always probes to see if a built-in FPU is present
  since this test can now be performed with the new APIC code.  However,
  an SMP kernel will panic if there is more than one CPU and a built-in
  FPU is not found.
- PCI interrupts are now properly routed when using APICs to route
  interrupts, so remove the hack to psuedo-route interrupts when the
  intpin register was read.
- The apic.h header was moved to apicreg.h and a new apicvar.h header
  that declares the APIs used by the new APIC code was added.
2003-11-03 21:53:38 +00:00