since BTLB entries can be scarce and very little of an I/O subsystem normally
needs to be mapped.
Instead, the pmap now allows mappings of I/O space to be entered with
pmap_kenter_pa. bus_space mappings for small amounts of I/O space (as for
virtually all devices) are made this way, with BTLB entries still used for
large mappings for things like framebuffers.
This has led to more and cleaned-up uses of bus_space(9) and has caused
some autoconf cleanup. Also, kgdb is now attached and connected before
autoconfiguration, which is much earlier than before.
in struct hppa_cpu_info or anywhere else, now there are just hppa_btlb_*
functions. Added support for machines with split I/D and variable-range
BTLBs. Added support for purging BTLB entries.
to deal with aliasing of regular memory pages, because many processors don't
support it.
Now, the pmap marks all mappings of a page that has any non-equivalent
aliasing and any writable mapping, and the fault handlers watch for this
and flush other mappings out of the TLB and cache before (re)entering a
conflicting mapping.
When a page has non-equivalent aliasing, only one writable mapping at
a time may be in the TLB and cache. If no writable mapping is in the
TLB and cache, any number of read-only mappings may be.
The PA7100LC/PA7300LC fault handlers have not been converted yet.
counters. These counters do not exist on all CPUs, but where they
do exist, can be used for counting events such as dcache misses that
would otherwise be difficult or impossible to instrument by code
inspection or hardware simulation.
pmc(9) is meant to be a general interface. Initially, the Intel XScale
counters are the only ones supported.
maps it with BTLB entries, to minimize the number of BTLB entries
needed.
Because the CPU type was often guessed incorrectly, the mapping of
HP board number to system name now includes information about the
expected CPU type.
* struct sigacts gets a new sigact_sigdesc structure, which has the
sigaction and the trampoline/version. Version 0 means "legacy kernel
provided trampoline". Other versions are coordinated with machine-
dependent code in libc.
* sigaction1() grows two more arguments -- the trampoline pointer and
the trampoline version.
* A new __sigaction_sigtramp() system call is provided to register a
trampoline along with a signal handler.
* The handler is no longer passed to sensig() functions. Instead,
sendsig() looks up the handler by peeking in the sigacts for the
process getting the signal (since it has to look in there for the
trampoline anyway).
* Native sendsig() functions now select the appropriate trampoline and
its arguments based on the trampoline version in the sigacts.
Changes to libc to use the new facility will be checked in later. Kernel
version not bumped; we will ride the 1.6C bump made recently.
