Add sh7724 code to save and restore CPG state during
R-standby. Only CPG registers IRDACLKCR and SPUCLKCR
require software save and restore.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
A number of small optimisations to FPU handling, in particular:
- move the task USEDFPU flag from the thread_info flags field (which
is accessed asynchronously to the thread) to a new status field,
which is only accessed by the thread itself. This allows locking to
be removed in most cases, or can be reduced to a preempt_lock().
This mimics the i386 behaviour.
- move the modification of regs->sr and thread_info->status flags out
of save_fpu() to __unlazy_fpu(). This gives the compiler a better
chance to optimise things, as well as making save_fpu() symmetrical
with restore_fpu() and init_fpu().
- implement prepare_to_copy(), so that when creating a thread, we can
unlazy the FPU prior to copying the thread data structures.
Also make sure that the FPU is disabled while in the kernel, in
particular while booting, and for newly created kernel threads,
In a very artificial benchmark, the execution time for 2500000
context switches was reduced from 50 to 45 seconds.
Signed-off-by: Stuart Menefy <stuart.menefy@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
sh port of the sLeAZY-fpu feature currently implemented for some architectures
such us i386.
Right now the SH kernel has a 100% lazy fpu behaviour.
This is of course great for applications that have very sporadic or no FPU use.
However for very frequent FPU users... you take an extra trap every context
switch.
The patch below adds a simple heuristic to this code: after 5 consecutive
context switches of FPU use, the lazy behavior is disabled and the context
gets restored every context switch.
After 256 switches, this is reset and the 100% lazy behavior is returned.
Tests with LMbench showed no regression.
I saw a little improvement due to the prefetching (~2%).
The tests below also show that, with this sLeazy patch, indeed,
the number of FPU exceptions is reduced.
To test this. I hacked the lat_ctx LMBench to use the FPU a little more.
sLeasy implementation
===========================================
switch_to calls | 79326
sleasy calls | 42577
do_fpu_state_restore calls| 59232
restore_fpu calls | 59032
Exceptions: 0x800 (FPU disabled ): 16604
100% Leazy (default implementation)
===========================================
switch_to calls | 79690
do_fpu_state_restore calls | 53299
restore_fpu calls | 53101
Exceptions: 0x800 (FPU disabled ): 53273
Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: Stuart Menefy <stuart.menefy@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
The typename member of struct irq_chip was kept for migration purposes
and is obsolete since more than 2 years. Fix up the leftovers.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-sh@vger.kernel.org
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Wanted by the SPU2 UIO driver, which really ought to be handling this
itself. Default enable it for now, until the driver gets a bit more
intelligent.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Add sh7724 code to save and restore RWDT state during
R-standby. Without this patch the watchdog will generate
a reset shortly after resuming from R-standby.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Add R-standby specific bits to the SuperH Mobile sleep code.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Use RSMEM instead of ILMEM for sleep mode code storage on SH7724.
This allows us to use R-standby mode on SH7724.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Add MMU and cache handling functionality to the SuperH Mobile
sleep code. The MMU and cache registers are saved and restored.
The MMU is disabled and the cache is flushed and disabled before
entering sleep modes if the SUSP_SH_MMU flag is set. This flag
should be set in the case of R-standby and most likely for future
U-standby support as well.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Add code to keep track of supported sleep modes. This to
only export cpuidle modes that are backed by board support
code. Also, do not allow suspend-to-ram if sdram board code
is missing.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Rework the SuperH Mobile sleep code from including
board specific code to allowing each board to provide
pre/post code snippets. These snippets should contain
sdram management code to enter and leave self-refresh.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Add code to allow boards registering self-contained
functions for going to/from self-refresh. At this
point the board code is unused. When all supported
boards have been converted then the new sleep code
will make use of these functions.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Make use of the recently added notifier chains for sh7724
r-standby register save/restore handling. At this point
only the BSC and INTC are handled.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This patch adds atomic notifier chains for pre/post
sleep events. Useful for cpu code and boards that
need to save and restore register state before and
after entering a sleep mode.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This adds in preliminary support for the SH-4A performance counters.
Presently only the first 2 counters are supported, as these are the ones
of the most interest to the perf tool and end users. Counter chaining is
not presently handled, so these are simply implemented as 32-bit
counters.
This also establishes a perf event support framework for other hardware
counters, which the existing SH-4 oprofile code will migrate over to as
the SH-4A support evolves.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
SCIF2 and the FPU exceptions happen to share vector numbers, one in
EXPEVT and the other in INTEVT. This is a violation of the interface and
should have never made it in to silicon. On top of that, the demux hack
that was added for special dispatch is rather error prone, and introduces
more problems than it solves. Kill all of it off, and just refuse to deal
with SCIF2 outright.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This code was added for some ancient SH-4 solution engines with peculiar
boot ROMs that did silly things to the UBC MSTP bits. None of these have
been in the wild for years, and these days the clock framework wraps up
the MSTP bits, meaning that the UBC code is one of the few interfaces
that is stomping MSTP bits underneath the clock framework. At this point
the risks far outweigh any benefit this code provided, so just kill it
off.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
All of the secondary CPUs are forced in to light sleep mode, but we were
missing the same initialization for the boot CPU. This resulted in
inconsistent sleep modes depending on which CPU we were on, confusing the
idle loop when not polling.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Replace TIF_RESTORE_SIGMASK with TS_RESTORE_SIGMASK and define our own
set_restore_sigmask() function. This saves the costly SMP-safe set_bit
operation, which we do not need for the sigmask flag since TIF_SIGPENDING
always has to be set too.
Based on the x86 and powerpc change.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
In the multi-evt conversion for the SH-X3 proto CPU, IRLs were dropped
down to a single unique masking source, which ended up blowing up on
ILSEL-based IRQs which have special semantics that otherwise confuse the
intc code. While this does result in intc spewing about not having a
unique masking source, we don't really care.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
There's already code in do_page_fault() to conditionally enable
interrupts, so we don't need to unconditonally enable them before
calling it. This fixes a lockdep warning where we called
trace_hardirqs_off() but with irqs still enabled.
Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This fixes up broken clock re-parenting undertaken by the SH7709 clock
framework code, which is currently in conflict with the legacy CPG
framework. With this change in place, the legacy CPG ancestry is used,
and we manage to avoid contending on the clock_list_sem mutex, which is
already held under the legacy registration path, resulting in livelock.
In order for SH7709 to fully support the varying clock modes, it needs to
implement a more complete clock framework. After this change it is in
sync with legacy CPG mode, which ends up being the default configuration
for this CPU anyways.
Signed-off-by: Rafael Ignacio Zurita <rizurita@yahoo.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
The kgdb stub has traditionally tied in to the NMI slot, and manually
handled debounce. Now that we have a generic way to do this instead, all
of the stub-specific debounce silliness can be killed off.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This implements support for NMI debugging that was shamelessly copied
from the avr32 port. A bit of special magic is needed in the interrupt
exception path given that the NMI exception handler is stubbed in to the
regular exception handling table despite being reported in INTEVT. So we
mangle the lookup and kick off an EXPEVT-style exception dispatch from
the INTEVT path for exceptions that do_IRQ() has no chance of handling.
As a result, we also drop the evt2irq() conversion from the do_IRQ() path
and just do it in assembly.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
It is possible for the CPU to re-enable it's interrupt block bit
before the write to the interrupt controller has actually masked out
the external interupt at the controller. We get around this by
reading back from the interrupt controller which will ensure the
write has happened.
Signed-off-by: Stuart Menefy <stuart.menefy@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
The SH instruction set has several instructions which accept an 8 bit
immediate operand. For logical instructions this operand is zero extended,
for arithmetic instructions the operand is sign extended. After adding an
option to the assembler to check this, it was found that several pieces
of assembly code were assuming this behaviour, and in one case
getting it wrong.
So this patch explicitly sign extends any immediate operands, which makes
it obvious what is happening, and fixes the one case which got it wrong.
Signed-off-by: Stuart Menefy <stuart.menefy@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
The Runtime PM patch for UIO driver implements coarse grained
dynamic power management for UIO devices. With that patch in
place we can get rid of the static clock configuration. Which
in turn makes it possible for cpuidle to enter deeper sleep.
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
The runtime PM for SH-Mobile code had platform_bus_notify() as __devinit,
which is rather bogus. Kill off the annotation, which subsequently
silences the section mismatch warnings.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This patch is V3 of the SuperH Mobile Runtime PM platform bus
implentation matching Rafael's Runtime PM v16.
The code gets invoked from the SuperH specific Runtime PM
platform bus functions that override the weak symbols for:
- platform_pm_runtime_suspend()
- platform_pm_runtime_resume()
- platform_pm_runtime_idle()
This Runtime PM implementation performs two levels of power
management. At the time of platform bus runtime suspend the
clock to the device is stopped instantly. Later on if all
devices within the power domain has their clocks stopped
then the device driver ->runtime_suspend() callbacks are
used to save hardware register state for each device.
Device driver ->runtime_suspend() calls are scheduled from
cpuidle context using platform_pm_runtime_suspend_idle().
When all devices have been fully suspended the processor
is allowed to enter deep sleep from cpuidle.
The runtime resume operation turns on clocks and also
restores registers if needed. It is worth noting that the
devices start in a suspended state and the device driver
is responsible for calling runtime resume before accessing
the actual hardware.
In this particular platform bus implementation runtime
resume is not allowed from interrupt context. Runtime
suspend is however allowed from interrupt context as
long as the synchronous functions are avoided.
[ updated for v17 -- PFM. ]
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
When CONFIG_DWARF_UNWINDER is enabled setup r14 in handle_interrupt, so
that we can figure out what function was running when we were
interrupted.
Signed-off-by: Matt Fleming <matt@console-pimps.org>
This fixes up the clockevents broadcasting code as detailed in commit
ee348d5a1d ("[ARM] realview: fix broadcast
tick support"). This saves us from having to do strange ordering things
with the broadcast clockevent device, relying on the rating instead.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This patch updates the FRQCRA.IFC divisor values for SH7724. Despite
not being initially documented, the / 3 mode is also support for the IFC
division.
Signed-off-by: Kuninori Morimoto <morimoto.kuninori@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
save_regs contains an SR modification without an irqflags annotation,
which resulted in a missing TRACE_IRQS_OFF in the interrupt exception
path on SH-3/SH4.
I've also moved the TRACE_IRQS_OFF/ON annotation when returning from the
interrupt to just before we call __restore_all. This seems like the most
logical place to put this because the annotation is for when we restore
the SR register so we should delay the annotation until as last as
possible.
We were also missing a TRACE_IRQS_OFF in resume_kernel when
CONFIG_PREEMPT is enabled.
The end result is that this fixes up the lockdep engine debugging support
with CONFIG_PREEMPT enabled on all SH-3/4 parts.
Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This patch adds "SuperH Mobile Standby Mode [SF]" to the list
of cpuidle sleep modes. If the software latency requirements
from cpuidle are met together with fulfilled hardware
requirements then deep sleep modes can be entered.
Tested on sh7722 and sh7724 with "Sleep Mode", "Sleep Mode + SF"
and "Software Standby Mode + SF" together with a multimedia
work load and flood ping without packet drop.
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
