we pass via sigctx, so that it guaranteed that the memory wouldn't be
paged out at the time the signal arrives
potential problem pointed out by YAMAMOTO Takashi
1) R10k uses VA0 to select cache ways, but in rev. 1.1, VA14
is used instead.
2) R10k does not support HitWriteBack and should map HitWriteBack
to HitWriteBackInvalidate, but in rev. 1.1, HitWriteBack is not
handled properly.
So, cache_r10k.c rev. 1.1 was replaced by new implementation.
generate unblocked upcalls in sa_unblock_userret(), before signal
delivery/p_userret handling in userret().
Also defer getting state for preempted upcalls because on some ports
preemption can happen between sa_unblock_userret() and sa_upcall_userret().
have one parent yet (on Darwin, multiple parents are possible: the IOKit
seems to handle a graph more than a tree). Introfuction of a keyboard
driver parent for IOHIDSystem.
The kernel keymapping is still a big mystery.
its state is saved:
- don't sa_putcachelwp() in sa_vp_repossess/sa_vp_donate
- only defer saving the event LWP's state
- sa_putcachelwp() after the interrupted LWP's state is saved
containing signal posting, kernel-exit handling and sa_upcall processing.
XXX the pc532, sparc, sparc64 and vax ports should have their
XXX userret() code rearranged to use this.
- Assume a permission fault is always the result of an attempted
write, so no need to disassemble the opcode.
(as discussed with Richard Earnshaw/Jason Thorpe a week or two ago)
- Split out non-MMU data aborts into separate functions, and deal
correctly with XScale imprecise aborts. Specifically, the old code
made no attempt to handle the double abort faults which can occur
as a result of two consecutive external (imprecise) aborts. This
was easy to provoke by read(2)ing from a /dev/mem offset which caused
an external abort. With the old code, this would bring the system
down instantly, with little clue as to why. (hint: tf_spsr held
PSR_ABT32_MODE...)
- Re-write badaddr_read() to use pcb_onfault instead of adding extra
overhead to data_abort_handler(). A side effect of this is that it
now benefits from the XScale double abort recovery.
- Invoke the cpu-specific prefetch/data abort fixup routines only if
the host cpu actually needs it. On other cpus, the code is optimised
away.
- Sprinkle __predict_{false,true} in all the right places.
- G/C some excess debugging baggage.
