Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

MFC r263080:
Use correct types for sizeof() in the calculations for the malloc(9) sizes.

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Add software PMC support.

New kernel events can be added at various location for sampling or counting.
This will for example allow easy system profiling whatever the processor is
with known tools like pmcstat(8).

Simultaneous usage of software PMC and hardware PMC is possible, for example
looking at the lock acquire failure, page fault while sampling on
instructions.

Sponsored by: NETASQ
MFC after: 1 month

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

Introduce cpu_vendor_id and replace a lot of strcmp(cpu_vendor, "...").

Reviewed by: jhb, peter (early amd64 version)

- Separate PMC class dependent code from other kinds of machine
dependencies. A 'struct pmc_classdep' structure describes operations
on PMCs; 'struct pmc_mdep' contains one or more 'struct pmc_classdep'
structures depending on the CPU in question.

Inside PMC class dependent code, row indices are relative to the
PMCs supported by the PMC class; MI code in "hwpmc_mod.c" translates
global row indices before invoking class dependent operations.

- Augment the OP_GETCPUINFO request with the number of PMCs present
in a PMC class.

- Move code common to Intel CPUs to file "hwpmc_intel.c".

- Move TSC handling to file "hwpmc_tsc.c".

Fix a number of style issues in the MALLOC / FREE commit. I've tried to
be careful not to fix anything that was already broken; the NFSv4 code is
particularly bad in this respect.

Retire the MALLOC and FREE macros. They are an abomination unto style(9).

MFC after: 3 months

Support sparsely numbered CPUs.

Requested by: obrien, alfred (long ago)

Kernel and hwpmc(4) support for callchain capture.

Sponsored by: FreeBSD Foundation and Google Inc.

Fix witness(4) warnings about mutex use.

Group mutexes used in hwpmc(4) into 3 "types" in the sense of
witness(4):

- leaf spin mutexes---only one of these should be held at a time,
so these mutexes are specified as belonging to a single witness
type "pmc-leaf".

- `struct pmc_owner' descriptors are protected by a spin mutex of
witness type "pmc-owner-proc". Since we call wakeup_one() while
holding these mutexes, the witness type of these mutexes needs
to dominate that of "sleepq chain" mutexes.

- logger threads use a sleep mutex, of type "pmc-sleep".

Submitted by: wkoszek (earlier patch)

Forcibly turn off all PMCs at module unload time.

MFC after: 1 week

Wrap comment lines to be under 80 characters wide.

MFC after: 3 days

Fix -Wundef warnings found when compiling i386 LINT, GENERIC and
custom kernels.

Bug fix initialization on multi-core HTT CPUs.

Reported by: ps
Tested by: ps

sys/dev/hwpmc/hwpmc_{amd,piv,ppro}.c:
- Update driver interrupt statistics correctly.

sys/sys/pmc.h, sys/dev/hwpmc/hwpmc_mod.c:
- Fix a bug affecting debug printfs.
- Move the 'stalled' flag from being in a bit in the
'pm_flags' field of a 'struct pmc' to a field of its own in the
same structure. This flag is updated from the NMI handler and
keeping it separate makes it easier to avoid races with other
parts of the code.

sys/dev/hwpmc/hwpmc_logging.c:
- Do arithmetic with 'uintptr_t' types rather that casting
to and from 'char *'.

Approved by: re (scottl)

MFP4:

- Implement sampling modes and logging support in hwpmc(4).

- Separate MI and MD parts of hwpmc(4) and allow sharing of
PMC implementations across different architectures.
Add support for P4 (EMT64) style PMCs to the amd64 code.

- New pmcstat(8) options: -E (exit time counts) -W (counts
every context switch), -R (print log file).

- pmc(3) API changes, improve our ability to keep ABI compatibility
in the future. Add more 'alias' names for commonly used events.

- bug fixes & documentation.

Kernel hooks to support PMC sampling modes.

Reviewed by: alc

Add convenience APIs pmc_width() and pmc_capabilities() to -lpmc.
Have pmcstat(8) and pmccontrol(8) use these APIs.

Return PMC class-related constants (PMC widths and capabilities)
with the OP GETCPUINFO call leaving OP PMCINFO to return only the
dynamic information associated with a PMC (i.e., whether enabled,
owner pid, reload count etc.).

Allow pmc_read() (i.e., OPS PMCRW) on active self-attached PMCs to
get upto-date values from hardware since we can guarantee that the
hardware is running the correct PMC at the time of the call.

Bug fixes:
- (x86 class processors) Fix a bug that prevented an RDPMC
instruction from being recognized as permitted till after the
attached process had context switched out and back in again after
a pmc_start() call.

Tighten the rules for using RDPMC class instructions: a GETMSR
OP is now allowed only after an OP ATTACH has been done by the
PMC's owner to itself. OP GETMSR is not allowed for PMCs that
track descendants, for PMCs attached to processes other than
their owner processes.

- (P4/HTT processors only) Fix a bug that caused the MI and MD
layers to get out of sync. Add a new MD operation 'get_config()'
as part of this fix.

- Allow multiple system-mode PMCs at the same row-index but on
different CPUs to be allocated.

- Reject allocation of an administratively disabled PMC.

Misc. code cleanups and refactoring. Improve a few comments.

Return the correct register number in the 'get_msr()' MD function.

Only allow a process to use the x86 RDPMC instruction if it has
allocated and attached a PMC to itself.

Inform the MD layer of the "pseudo context switch out" that needs
to be done when the last thread of a process is exiting.

Forced commit to note the move from "src/sys/hwpmc" to "src/sys/dev/hwpmc".

Include <sys/pmc.h> instead of <machine/pmc_mdep.h>. The MI header
includes the MD header for us. Do not include <machine/specialreg.h>
as it is not a header file that can be included from MI files. It
is included from <machine/pmc_mdep.h> if so needed and possible.

Ok'd: jkoshy@

Remove unused variable that was horking up the LINT build

Bring a working snapshot of hwpmc(4), its associated libraries, userland utilities
and documentation into -CURRENT.

Bump FreeBSD_version.

Reviewed by: alc, jhb (kernel changes)