page. Therefore, it is really inappropriate for use by the function
uma_small_alloc(). The effect of using it was that every page was zeroed
at least once and possibly twice if M_ZERO was passed as a "wait" flag.
instruction loads/stores at its will.
The macro __compiler_membar() is currently supported for both gcc and
clang, but kernel compilation will fail otherwise.
Reviewed by: bde, kib
Discussed with: dim, theraven
MFC after: 2 weeks
advantages. First, PV entries are roughly half the size. Second, this
allocator doesn't access the paging queues, and thus it will allow for the
removal of the page queues lock from this pmap.
Fix a rather serious bug in pmap_remove_write(). After removing write
access from the specified page's first mapping, pmap_remove_write() then
used the wrong "next" pointer. Consequently, the page's second, third,
etc. mappings were not write protected.
Tested by: jchandra
Reduce the size of a PV entry by eliminating pv_ptem. There is no need
to store a pointer to the page table page in the PV entry because it is
easily computed during the walk down the page table.
Eliminate the ptphint from the pmap. Long, long ago, page table pages
belonged to a vm object, and we would look up page table pages based
upon their offset within this vm object. In those days, this hint may
have had tangible benefits.
Tested by: jchandra
This is required for ARM EABI. Section 7.1.1 of the Procedure Call for the
ARM Architecture (AAPCS) defines wchar_t as either an unsigned int or an
unsigned short with the former preferred.
Because of this requirement we need to move the definition of __wchar_t to
a machine dependent header. It also cleans up the macros defining the limits
of wchar_t by defining __WCHAR_MIN and __WCHAR_MAX in the same machine
dependent header then using them to define WCHAR_MIN and WCHAR_MAX
respectively.
Discussed with: bde
usermode, using shared page. The structures and functions have vdso
prefix, to indicate the intended location of the code in some future.
The versioned per-algorithm data is exported in the format of struct
vdso_timehands, which mostly repeats the content of in-kernel struct
timehands. Usermode reading of the structure can be lockless.
Compatibility export for 32bit processes on 64bit host is also
provided. Kernel also provides usermode with indication about
currently used timecounter, so that libc can fall back to syscall if
configured timecounter is unknown to usermode code.
The shared data updates are initiated both from the tc_windup(), where
a fast task is queued to do the update, and from sysctl handlers which
change timecounter. A manual override switch
kern.timecounter.fast_gettime allows to turn off the mechanism.
Only x86 architectures export the real algorithm data, and there, only
for tsc timecounter. HPET counters page could be exported as well, but
I prefer to not further glue the kernel and libc ABI there until
proper vdso-based solution is developed.
Minimal stubs neccessary for non-x86 architectures to still compile
are provided.
Discussed with: bde
Reviewed by: jhb
Tested by: flo
MFC after: 1 month
layer, but it is read directly by the MI VM layer. This change introduces
pmap_page_is_write_mapped() in order to completely encapsulate all direct
access to PGA_WRITEABLE in the pmap layer.
Aesthetics aside, I am making this change because amd64 will likely begin
using an alternative method to track write mappings, and having
pmap_page_is_write_mapped() in place allows me to make such a change
without further modification to the MI VM layer.
As an added bonus, tidy up some nearby comments concerning page flags.
Reviewed by: kib
MFC after: 6 weeks
in_cksum.h required ip.h to be included for struct ip. To be
able to use some general checksum functions like in_addword()
in a non-IPv4 context, limit the (also exported to user space)
IPv4 specific functions to the times, when the ip.h header is
present and IPVERSION is defined (to 4).
We should consider more general checksum (updating) functions
to also allow easier incremental checksum updates in the L3/4
stack and firewalls, as well as ponder further requirements by
certain NIC drivers needing slightly different pseudo values
in offloading cases. Thinking in terms of a better "library".
Sponsored by: The FreeBSD Foundation
Sponsored by: iXsystems
Reviewed by: gnn (as part of the whole)
MFC After: 3 days
This makes our naming scheme more closely match other systems and the
expectations of much third-party software. MIPS builds which are little-endian
should require and exhibit no changes. Big-endian TARGET_ARCHes must be
changed:
From: To:
mipseb mips
mipsn32eb mipsn32
mips64eb mips64
An entry has been added to UPDATING and some foot-shooting protection (complete
with warnings which should become errors in the near future) to the top-level
base system Makefile.
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
- Replace MIPS24K-specific code with more generic framework that will
make adding new CPU support easier
- Add MIPS24K support for new framework
- Limit backtrace depth to 1 for stability reasons and add option
HWPMC_MIPS_BACKTRACE to override this limitation
required for the ABI the kernel is being built for.
XXX This is implemented in a kind-of nasty way that involves including source
files, but it's still an improvement.
o) Retire ISA_* options since they're unused and were always wrong.
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.
TLS:
o) The mc_tls field used to store the TLS base when doing context gets and
restores was left a pointer and not converted to a 32-bit integer. This
had the bug of not correctly capturing the TLS value desired by the user,
and the extra nastiness of making the structure the wrong size.
o) The mc_tls field was not being saved by sendsig. As a result, the TLS base
would always be set to NULL when restoring from a signal handler.
Thanks to gonzo for helping track down a bunch of other TLS bugs that came out
of tracking these down.
and offset it only if requested by RDHWR handler. Otherwise things
get overly complicated - we need to track whether address passsed in
request for setting td_md.md_tls is already offseted or not.
using the o32 ABI. This mostly follows nwhitehorn's lead in implementing
COMPAT_FREEBSD32 on powerpc64.
o) Add a new type to the freebsd32 compat layer, time32_t, which is time_t in the
32-bit ABI being used. Since the MIPS port is relatively-new, even the 32-bit
ABIs use a 64-bit time_t.
o) Because time{spec,val}32 has the same size and layout as time{spec,val} on MIPS
with 32-bit compatibility, then, disable some code which assumes otherwise
wrongly when built for MIPS. A more general macro to check in this case would
seem like a good idea eventually. If someone adds support for using n32
userland with n64 kernels on MIPS, then they will have to add a variety of
flags related to each piece of the ABI that can vary. That's probably the
right time to generalize further.
o) Add MIPS to the list of architectures which use PAD64_REQUIRED in the
freebsd32 compat code. Probably this should be generalized at some point.
Reviewed by: gonzo
Reading register $29 with RDHWR is becoming the de-facto standard to
implement TLS. According to linux-mips wiki, MIPS Technologies has
reserved hardware register $29 for ABI use. Furthermore current GCC
makes the following assumptions:
- RDHWR is natively available or otherwise emulated by the kernel
- Register $29 holds the TLS pointer
Submitted by: Robert Millan <rmh@debian.org>
implement a deprecated FPU control interface in addition to the
standard one. To make this clearer, further deprecate ieeefp.h
by not declaring the function prototypes except on architectures
that implement them already.
Currently i386 and amd64 implement the ieeefp.h interface for
compatibility, and for fp[gs]etprec(), which doesn't exist on
most other hardware. Powerpc, sparc64, and ia64 partially implement
it and probably shouldn't, and other architectures don't implement it
at all.
If we handle an interrupt just before the 'wait' and the interrupt
schedules some work, we need to skip the 'wait' call. The simple solution
of calling sched_runnable() with interrupts disabled immediately before
wait still leaves a window after the call and before 'wait' in which
the same issue can occur.
The solution implemented is to check the EPC in the interrupt handler, and
if it is in a region before the 'wait' call, to fix up the EPC to skip the
wait call.
Reported/analysed by: adrian
Fix suggested by: kib
Reviewed by: jmallett, imp
- update xlp_machdep.c to read arguments from FDT if FDT support is
compiled in.
- define rmi_uart_bus_space, and use it as fdtbus_bs_tag
- update conf files for FDT support
- add default dts file xlp-basic.dts
