The "nofpu" and "nodsp" kernel command line options currently do not
affect CPUs that are brought online later in the boot process or
hotplugged at runtime. It is desirable to apply the nofpu/nodsp options
to all CPUs in the system, so that surprising results are not seen when
a process migrates from one CPU to another.
[Ralf: Moved definitions of mips_fpu_disabled, fpu_disable,
mips_dsp_disabled and dsp_disable from setup.c to cpu-probe.c to allow
making mips_fpu_disabled and mips_dsp_disabled static.]
Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: http://patchwork.linux-mips.org/patch/1169/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The userspace runtime linker uses the elf_platform to find the libraries
optimized for the current CPU archecture variant. First we need to allow it
to be set to something other than NULL. Follow-on patches will set some
values for specific CPUs.
GLIBC already does the right thing. The kernel just needs to supply good
data.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/891/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
To: linux-mips@linux-mips.org
To: Andrew Morton <akpm@linux-foundation.org>
To: LKML <linux-kernel@vger.kernel.org>
Patchwork: http://patchwork.linux-mips.org/patch/860/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
For processors that have more than 64 TLBs, we need to decode both
config1 and config4 to determine the total number TLBs.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/866/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The patch that adds cpu_probe_vmbits is erroneously writing to reserved
bit 12. Since we are really only probing high bits, don't write this bit
with a one.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Cc: Guenter Roeck <guenter.roeck@ericsson.com>
Patchwork: http://patchwork.linux-mips.org/patch/949/
Acked-by: Guenter Roeck <guenter.roeck@ericsson.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Linux kernel 2.6.32 and later allocate address space from the top of the
kernel virtual memory address space.
This patch implements virtual memory size detection for 64 bit MIPS CPUs
to avoid resulting crashes.
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/935/
Reviewed-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Loongson 2F supports CPU clock scaling. When put it into wait mode by
setting the frequency as ZERO it will stay in this mode until an external
interrupt wakes the CPU again.
To enable clock scaling support, an external timer of a known stable rate
is required.
Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: cpufreq@vger.kernel.org,
Cc: Dave Jones <davej@redhat.com>,
Cc: Dominik Brodowski <linux@dominikbrodowski.net>,
Cc: yanh@lemote.com
Cc: huhb@lemote.com,
Patchwork: http://patchwork.linux-mips.org/patch/660/
Patchwork: http://patchwork.linux-mips.org/patch/751/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Todo: Nothing ever detects CPU_BCM6338 but the code tests for it anyway.
Signed-off-by: Maxime Bizon <mbizon@freebox.fr>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Eliminate the 'allow_au1k_wait' variable. MIPS kernel installs the
Alchemy-specific wait code before timer initialization; if the C0
timer must be used for timekeeping the wait function is set to NULL
which means no wait implementation is available.
As a sideeffect, the 'wait instruction available' output in
/proc/cpuinfo now correctly indicates whether 'wait' is usable.
Run-tested on DB1200.
Signed-off-by: Manuel Lauss <manuel.lauss@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Some of the were relying into smp.h being dragged in by another header
which of course is fragile. <asm/cpu-info.h> uses smp_processor_id()
only in macros and including smp.h there leads to an include loop, so
don't change cpu-info.h.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This patch removes the various CPU_AU1??? model constants in favor of
a single CPU_ALCHEMY one.
All currently existing Alchemy models are identical in terms of cpu
core and cache size/organization. The parts of the mips kernel which
need to know the exact CPU revision extract it from the c0_prid register
already; and finally nothing else in-tree depends on those any more.
Should a new variant with slightly different "company options" and/or
"processor revision" bits in c0_prid appear, it will be supported
immediately (minus an exact model string in cpuinfo).
Signed-off-by: Manuel Lauss <mano@roarinelk.homelinux.net>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Current VR5500 processor support lacks of some functions which are
expected to be configured/synthesized on arch initialization.
Here're some VR5500A spec notes:
* All execution hazards are handled in hardware.
* Once VR5500A stops the operation of the pipeline by WAIT instruction,
it could return from the standby mode only when either a reset, NMI
request, or all enabled interrupts is/are detected. In other words,
if interrupts are disabled by Status.IE=0, it keeps in standby mode
even when interrupts are internally asserted.
Notes on WAIT: The operation of the processor is undefined if WAIT
insn is in the branch delay slot. The operation is also undefined
if WAIT insn is executed when Status.EXL and Status.ERL are set to 1.
* VR5500A core only implements the Load prefetch.
With these changes, it boots fine.
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi@necel.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Add support for the 32 kHz counter1 (RTC) as clocksource / clockevent
device. As a nice side effect, this also enables use of the 'wait'
instruction for runtime idle power savings.
If the counters aren't enabled/working properly, fall back on the
cp0 counter clock code.
Signed-off-by: Manuel Lauss <mano@roarinelk.homelinux.net>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Add OCTEON constants to asm/cpu.h and asm/module.h.
Add probe function for Cavium OCTEON CPUs and hook it up.
Signed-off-by: Tomaso Paoletti <tpaoletti@caviumnetworks.com>
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
As noticed by David Daney <ddaney@caviumnetworks.com>, the old long switch
statement did not comply with the Linux C coding style. It was also yet
another place of code to be changed when adding a new processor type
leading to annoying bugs for example in /proc/cpuinfo.
Fixed by moving the setting of the CPU type string into the core of the
probing code and a few BUG_ON() test to ensure the CPU probing code indeed
did its job and removing multiple now redundant tests.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Probe for watch register characteristics, and report them in /proc/cpuinfo.
Signed-off-by: David Daney <ddaney@avtrex.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Rework of SMTC support to make it work with the new clock event system,
allowing "tickless" operation, and to make it compatible with the use of
the "wait_irqoff" idle loop. The new clocking scheme means that the
previously optional IPI instant replay mechanism is now required, and has
been made more robust.
Signed-off-by: Kevin D. Kissell <kevink@paralogos.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
If an interrupt happened between checking of NEED_RESCHED and WAIT
instruction, adjust EPC to restart from checking of NEED_RESCHED.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This patch adds IDs for new Au1200 variants: Au1210 and Au1250.
They are essentially identical to the Au1200 except for the Au1210
which has a different SoC-ID in the PRId register [bits 31:24].
The Au1250 is a "Au1200 V0.2".
Signed-off-by: Manuel Lauss <mano@roarinelk.homelinux.net>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Shadow register support would not possibly have worked on multicore
systems. The support code for it was also depending not on MIPS R2 but
VSMP or SMTC kernels even though it makes perfect sense with UP kernels.
SR sets are a scarce resource and the expected usage pattern is that
users actually hardcode the register set numbers in their code. So fix
the allocator by ditching it. Move the remaining CPU probe bits into
the generic CPU probe.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
So far /proc/cpuinfo has been the only user but human readable processor
name are more useful than that for proc.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
It may not be perfect yet but the SB1 code is badly borken and has
horrible performance issues.
Downside: This seriously breaks support for pass 1 parts of the BCM1250
where indexed cacheops don't work quite reliable but I seem to be the
last one on the planet with a pass 1 part anyway.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Note that the BCM4710 does not support the wait instruction, this
is not a mistake in the code.
It originally comes from the OpenWrt patches.
Cc: Michael Buesch <mb@bu3sch.de>
Cc: Felix Fietkau <nbd@openwrt.org>
Cc: Florian Schirmer <jolt@tuxbox.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Another issue with 20Kc's WAIT, waiting for more details. With the
2.6.23 release immindent simply disable the use of WAIT instead of a
more fancy workaround.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Patch to add mips common support for the PMC-Sierra MSP71xx devices.
Signed-off-by: Marc St-Jean <Marc_St-Jean@pmc-sierra.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Which will cut down the cost of RDHWR $29 which is used to obtain the
TLS pointer and so far being emulated in software down to a single cycle
operation.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The idle loop goes to sleep using the WAIT instruction if !need_resched().
This has is suffering from from a race condition that if if just after
need_resched has returned 0 an interrupt might set TIF_NEED_RESCHED but
we've just completed the test so go to sleep anyway. This would be
trivial to fix by just disabling interrupts during that sequence as in:
local_irq_disable();
if (!need_resched())
__asm__("wait");
local_irq_enable();
but the processor architecture leaves it undefined if a processor calling
WAIT with interrupts disabled will ever restart its pipeline and indeed
some processors have made use of the freedom provided by the architecture
definition. This has been resolved and the Config7.WII bit indicates that
the use of WAIT is safe on 24K, 24KE and 34K cores. It also is safe on
74K starting revision 2.1.0 so enable the use of WAIT with interrupts
disabled for 74K based on a c0_prid of at least that.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
We used to avoid the WAIT entirely on the 20K but really only need to do
this on early revs of the 20K. Without this a 20K was a bit of a
power hog. Well, in the lower power power hog category ;-)
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This fixes some sparse warnings. ("warning: symbol 'foo' was not
declared. Should it be static?")
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Only revisions < 4.0 don't have a functional wait instruction.
From Thomas Koeller (Thomas.Koeller@baslerweb.com).
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
If a thread became runnable between need_resched() and the WAIT
instruction, switching to the thread will delay until a next interrupt.
Some CPUs can execute the WAIT instruction with interrupt disabled, so
we can get rid of this race on them (at least UP case).
Original Patch by Atsushi with fixing up for MIPS Technology's cores by
Ralf based on feedback from the RTL designers.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The appended patch drops the inline for decode_configs, this saves about
2k of text size.
Signed-off-by: Thiemo Seufer <ths@networkno.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
