implementations or no implementation on all platforms.
Some of these functions might be good ideas, but their semantics were unclear
given the lack of implementation, and an unlucky porter could be fooled into
trying to implement them or, worse, being baffled when something like
platform_trap_enter() failed to be called.
o) Get rid of some unused macros related to features we don't intend to
provide.
o) Get rid of macro definitions for MIPS-I CPUs. We are not likely to
support anything that predartes MIPS-III.
o) Respell MIPS3_* macros as MIPS_*, which is how most of them were being
used already.
o) Eliminate a duplicate and mostly-unused set of exception vector macros.
There's still considerable duplication and lots more obsolete in our headers,
but this reduces one of the larger files to a size where one could reckon
about the correctness of its contents with a mere few hours of contemplation.
There is, of course, a question of whether we need definitions for fields,
registers and configurations that we are unlikely to ever use or implement,
even if they're not obsolete since 1991. FreeBSD is not a processor
reference manual, and things that aren't used may be wrong, or may be
duplicated because nobody could possibly actually know whether they're
already defined.
'counter_upper' and 'counter_lower_last'. The race exists because
interrupts are enabled even though tick_ticker() executes in a
critical section.
Fix a bug in clock_intr() in how it updates the cached values of
'counter_upper' and 'counter_lower_last'. They are updated only
when the COUNT register rolls over. More interestingly it will *never*
update the cached values if 'counter_lower_last' happens to be zero.
Get rid of superfluous critical section in clock_intr(). There is no
reason to do this because clock_intr() executes in hard interrupt
context.
Switch back to using 'tick_ticker()' as the cpu ticker for Sibyte.
Reviewed by: jmallett, mav
physical addresses.
o) Set a local maxmem in sb_machdep.c to avoid trying to use pages over 2^64
under 32-bit ABIs. Our pmap needs corrected to use vm_paddr_t consistently,
then we can make vm_paddr_t 64-bit under 32-bit ABIs and add code in pmap
to limit phys_avail by the maximum PFN that a 32-bit PTE can hold.
frequency. This counter can be accessed coherently from both cores.
Use this as the preferred timecounter for the SWARM kernels.
The CP0 COUNT register is unusable as the timecounter on SMP platforms because
the COUNT registers on different CPUs are not guaranteed to be in sync.
- We don't need to fall back to uncacheable memory to satisfy BUS_DMA_COHERENT
requests on these CPUs.
- The bus_dmamap_sync() is a no-op for these CPUs.
A side-effect of this change is rename DMAMAP_COHERENT flag to
DMAMAP_UNCACHEABLE. This conveys the purpose of the flag more accurately.
Reviewed by: gonzo, imp
The platform that supports SMP currently is a SWARM with a dual-core Sibyte
processor. The kernel config file to use is SWARM_SMP.
Reviewed by: imp, rrs
This is a workaround for the fact that the CFE is compiled as a 64-bit
application and therefore sets the SR_KX bit every time we call into
it (for e.g. console).
A TLB miss for any address above 0xc0000000 with the SR_KX bit set will
end up at the XTLB exception vector. We workaround this by copying the
standard TLB handler at the XTLB exception vector.
Approved by: imp (mentor)
symbols resolving in DDB
- When zeroing .bss/.sbss do not round end address to page boundary,
it's not neccessary and might destroy data pased by trampoline or
boot loader
