when the user has indicated that the system has synchronized TSCs or it has
P-state invariant TSCs. For the former case, we may clear the tunable if it
fails the test to prevent accidental foot-shooting. For the latter case, we
may set it if it passes the test to notify the user that it may be usable.
versions instead. They were never needed as bus_generic_intr() and
bus_teardown_intr() had been changed to pass the original child device up
in 42734, but the ISA bus was not converted to new-bus until 45720.
This fixes heavy interrupt storm and resulting system freeze when using
LAPIC timer in one-shot mode under Xen HVM. There, unlike real hardware,
programming timer with zero period almost immediately causes interrupt.
driver would verify that requests for child devices were confined to any
existing I/O windows, but the driver relied on the firmware to initialize
the windows and would never grow the windows for new requests. Now the
driver actively manages the I/O windows.
This is implemented by allocating a bus resource for each I/O window from
the parent PCI bus and suballocating that resource to child devices. The
suballocations are managed by creating an rman for each I/O window. The
suballocated resources are mapped by passing the bus_activate_resource()
call up to the parent PCI bus. Windows are grown when needed by using
bus_adjust_resource() to adjust the resource allocated from the parent PCI
bus. If the adjust request succeeds, the window is adjusted and the
suballocation request for the child device is retried.
When growing a window, the rman_first_free_region() and
rman_last_free_region() routines are used to determine if the front or
end of the existing I/O window is free. From using that, the smallest
ranges that need to be added to either the front or back of the window
are computed. The driver will first try to grow the window in whichever
direction requires the smallest growth first followed by the other
direction if that fails.
Subtractive bridges will first attempt to satisfy requests for child
resources from I/O windows (including attempts to grow the windows). If
that fails, the request is passed up to the parent PCI bus directly
however.
The PCI-PCI bridge driver will try to use firmware-assigned ranges for
child BARs first and only allocate a "fresh" range if that specific range
cannot be accommodated in the I/O window. This allows systems where the
firmware assigns resources during boot but later wipes the I/O windows
(some ACPI BIOSen are known to do this) to "rediscover" the original I/O
window ranges.
The ACPI Host-PCI bridge driver has been adjusted to correctly honor
hw.acpi.host_mem_start and the I/O port equivalent when a PCI-PCI bridge
makes a wildcard request for an I/O window range.
The new PCI-PCI bridge driver is only enabled if the NEW_PCIB kernel option
is enabled. This is a transition aide to allow platforms that do not
yet support bus_activate_resource() and bus_adjust_resource() in their
Host-PCI bridge drivers (and possibly other drivers as needed) to use the
old driver for now. Once all platforms support the new driver, the
kernel option and old driver will be removed.
PR: kern/143874 kern/149306
Tested by: mav
constraints on the rman and reject attempts to manage a region that is out
of range.
- Fix various places that set rm_end incorrectly (to ~0 or ~0u instead of
~0ul).
- To preserve existing behavior, change rman_init() to set rm_start and
rm_end to allow managing the full range (0 to ~0ul) if they are not set by
the caller when rman_init() is called.
VMware products virtualize TSC and it run at fixed frequency in so-called
"apparent time". Although virtualized i8254 also runs in apparent time, TSC
calibration always gives slightly off frequency because of the complicated
timer emulation and lost-tick correction mechanism.
disk dumping.
With the option SW_WATCHDOG on, these operations are doomed to let
watchdog fire, fi they take too long.
I implemented the stubs this way because I really want wdog_kern_*
KPI to not be dependant by SW_WATCHDOG being on (and really, the option
only enables watchdog activation in hardclock) and also avoid to
call them when not necessary (avoiding not-volountary watchdog
activations).
Sponsored by: Sandvine Incorporated
Discussed with: emaste, des
MFC after: 2 weeks
invariant and APERF/MPERF MSRs exist but these MSRs never tick. When we
calculate effective frequency from cpu_est_clockrate(), it caused panic of
division-by-zero. Now we test whether these MSRs actually increase to avoid
such foot-shooting.
Reported by: dim
Tested by: dim
safer for i386 because it can be easily over 4 GHz now. More worse, it can
be easily changed by user with 'machdep.tsc_freq' tunable (directly) or
cpufreq(4) (indirectly). Note it is intentionally not used in performance
critical paths to avoid performance regression (but we should, in theory).
Alternatively, we may add "virtual TSC" with lower frequency if maximum
frequency overflows 32 bits (and ignore possible incoherency as we do now).
started to execute, it seems that the corresponding ISR bit in the "old"
local APIC can be cleared. This causes the local APIC interrupt routine
to fail to find an interrupt to service. Rather than panic'ing in this
case, simply return from the interrupt without sending an EOI to the
local APIC. If there are any other pending interrupts in other ISR
registers, the local APIC will assert a new interrupt.
Tested by: steve
bus_size_t may be 32 or 64 bits. Change the bounce_zone alignment field
to explicitly be 32 bits, as I can't really imagine a DMA device that
needs anything close to 2GB alignment of data.
interrupt in the I/O APIC before moving it to a different CPU. If the
interrupt had been triggered by the I/O APIC after locking icu_lock but
before we masked the pin in the I/O APIC, then this could cause the
interrupt to be pending on the "old" CPU and it would finally trigger
after we had moved the interrupt to the new CPU. This could cause us to
panic as there was no interrupt source associated with the old IDT vector
on the old CPU. Dropping the lock after the interrupt is masked but
before it is moved allows the interrupt to fire and be handled in this
case before it is moved.
Tested by: Daniel Braniss danny of cs huji ac il
MFC after: 1 week
the original amd64 and i386 headers with stubs.
Rename (AMD64|I386)_BUS_SPACE_* to X86_BUS_SPACE_* everywhere.
Reviewed by: imp (previous version), jhb
Approved by: kib (mentor)
- Avoid side-effect assignments in if statements when possible.
- Don't use ! to check for NULL pointers, explicitly check against NULL.
- Explicitly check error return values against 0.
- Don't use INTR_MPSAFE for interrupt handlers with only filters as it is
meaningless.
- Remove unneeded function casts.
Also, add a comment mentioning _PSD - on some systems it's enough to
put one logical CPU into a particular P-state to make other CPUs in
the same domain to enter that P-state.
Also, call sched_unbind() after the loop - sched_bind() automatically
rebinds from previous CPU to a new one, and the new arrangement of code
is safer against early loop exit.
Plus one minor style nit.
MFC after: 10 days
