Now that associative cache writes are no longer needed by the SH-4/SH-4A
cache flush code, associative write support can be explicitly disabled
for all SH-4A parts. This makes any associative write throw an exception,
as this behaviour can not be assumed to exist on future parts.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This patch updates the Runtime PM code for SuperH Mobile
to allow drivers to have NULL as pm or callback value.
With this in place there is no need for no-op functions.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
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>
