提交 · 538f19526e40ce7a5a296fad6a3121409c890adc · openeuler / raspberrypi-kernel

17 12月, 2009 40 次提交

MIPS: Tracing: Add dynamic function tracer support · 538f1952

由 Wu Zhangjin 提交于 11月 20, 2009

With dynamic function tracer, by default, _mcount is defined as an
"empty" function, it returns directly without any more action . When
enabling it in user-space, it will jump to a real tracing
function(ftrace_caller), and do the real job for us.

Differ from the static function tracer, dynamic function tracer provides
two functions ftrace_make_call()/ftrace_make_nop() to enable/disable the
tracing of some indicated kernel functions(set_ftrace_filter).

In the -v4 version, the implementation of this support is basically the same as
X86 version does: _mcount is implemented as an empty function and ftrace_caller
is implemented as a real tracing function respectively.

But in this version, to support module tracing with the help of
-mlong-calls in arch/mips/Makefile:

MODFLAGS += -mlong-calls.

The stuff becomes a little more complex. We need to cope with two
different type of calling to _mcount.

For the kernel part, the calling to _mcount(result of "objdump -hdr
vmlinux"). is like this:

	108:   03e0082d        move    at,ra
	10c:   0c000000        jal     0 <fpcsr_pending>
                        10c: R_MIPS_26  _mcount
                        10c: R_MIPS_NONE        *ABS*
                        10c: R_MIPS_NONE        *ABS*
	110:   00020021        nop

For the module with -mlong-calls, it looks like this:

	c:	3c030000 	lui	v1,0x0
			c: R_MIPS_HI16	_mcount
			c: R_MIPS_NONE	*ABS*
			c: R_MIPS_NONE	*ABS*
	10:	64630000 	daddiu	v1,v1,0
			10: R_MIPS_LO16	_mcount
			10: R_MIPS_NONE	*ABS*
			10: R_MIPS_NONE	*ABS*
	14:	03e0082d 	move	at,ra
	18:	0060f809 	jalr	v1

In the kernel version, there is only one "_mcount" string for every
kernel function, so, we just need to match this one in mcount_regex of
scripts/recordmcount.pl, but in the module version, we need to choose
one of the two to match. Herein, I choose the first one with
"R_MIPS_HI16 _mcount".

and In the kernel verion, without module tracing support, we just need
to replace "jal _mcount" by "jal ftrace_caller" to do real tracing, and
filter the tracing of some kernel functions via replacing it by a nop
instruction.

but as we have described before, the instruction "jal ftrace_caller" only left
32bit length for the address of ftrace_caller, it will fail when calling from
the module space. so, herein, we must replace something else.

the basic idea is loading the address of ftrace_caller to v1 via changing these
two instructions:

	lui	v1,0x0
	addiu	v1,v1,0

If we want to enable the tracing, we need to replace the above instructions to:

	lui	v1, HI_16BIT_ftrace_caller
	addiu	v1, v1, LOW_16BIT_ftrace_caller

If we want to stop the tracing of the indicated kernel functions, we
just need to replace the "jalr v1" to a nop instruction. but we need to
replace two instructions and encode the above two instructions
oursevles.

Is there a simpler solution? Yes! Here it is, in this version, we put _mcount
and ftrace_caller together, which means the address of _mcount and
ftrace_caller is the same:

_mcount:
ftrace_caller:
	j	ftrace_stub
	 nop

	...(do real tracing here)...

ftrace_stub:
	jr	ra
	 move	ra, at

By default, the kernel functions call _mcount, and then jump to ftrace_stub and
return. and when we want to do real tracing, we just need to remove that "j
ftrace_stub", and it will run through the two "nop" instructions and then do
the real tracing job.

what about filtering job? we just need to do this:

	 lui v1, hi_16bit_of_mcount        <--> b 1f (0x10000004)
	 addiu v1, v1, low_16bit_of_mcount
	 move at, ra
	 jalr v1
	 nop
	 				     1f: (rec->ip + 12)

In linux-mips64, there will be some local symbols, whose name are
prefixed by $L, which need to be filtered. thanks goes to Steven for
writing the mips64-specific function_regex.

In a conclusion, with RISC, things becomes easier with such a "stupid"
trick, RISC is something like K.I.S.S, and also, there are lots of
"simple" tricks in the whole ftrace support, thanks goes to Steven and
the other folks for providing such a wonderful tracing framework!
Signed-off-by: NWu Zhangjin <wuzhangjin@gmail.com>
Cc: Nicholas Mc Guire <der.herr@hofr.at>
Cc: zhangfx@lemote.com
Cc: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/675/Acked-by: NSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

538f1952

MIPS: Tracing: Add an endian argument to scripts/recordmcount.pl · e6299d26

由 Wu Zhangjin 提交于 11月 20, 2009

MIPS and some other architectures need this argument to handle
big/little endian respectively.
Signed-off-by: NWu Zhangjin <wuzj@lemote.com>
Cc: Nicholas Mc Guire <der.herr@hofr.at>
Cc: zhangfx@lemote.com
Cc: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/674/Acked-by: NSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

e6299d26

MIPS: Tracing: Enable HAVE_FUNCTION_TRACE_MCOUNT_TEST for MIPS · 69a7d1b3

由 Wu Zhangjin 提交于 11月 20, 2009

There is an exisiting common ftrace_test_stop_func() in
kernel/trace/ftrace.c, which is used to check the global variable
ftrace_trace_stop to determine whether stop the function tracing.

This patch implepment the MIPS specific one to speedup the procedure.

Thanks goes to Zhang Le for Cleaning it up.
Signed-off-by: NWu Zhangjin <wuzhangjin@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Nicholas Mc Guire <der.herr@hofr.at>
Cc: zhangfx@lemote.com
Cc: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/673/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

69a7d1b3

MIPS: Tracing: Add static function tracer support for MIPS · d2bb0762

由 Wu Zhangjin 提交于 11月 20, 2009

If -pg of gcc is enabled with CONFIG_FUNCTION_TRACER=y. a calling to
_mcount will be inserted into each kernel function. so, there is a
possibility to trace the kernel functions in _mcount.

This patch add the MIPS specific _mcount support for static function
tracing. by default, ftrace_trace_function is initialized as
ftrace_stub(an empty function), so, the default _mcount will introduce
very little overhead. after enabling ftrace in user-space, it will jump
to a real tracing function and do static function tracing for us.

and -ffunction-sections is incompatible with -pg, so, disable it when
ftracer is enabled.
Signed-off-by: NWu Zhangjin <wuzhangjin@gmail.com>
Reviewed-by: NSteven Rostedt <rostedt@goodmis.org>
Cc: Nicholas Mc Guire <der.herr@hofr.at>
Cc: zhangfx@lemote.com
Cc: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/672/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

d2bb0762

MIPS: Fixup last users of irq_chip->typename · 8922f79e

由 Thomas Gleixner 提交于 11月 17, 2009

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: NThomas Gleixner <tglx@linutronix.de>
Cc: linux-mips@linux-mips.org
To: LKML <linux-kernel@vger.kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Patchwork: http://patchwork.linux-mips.org/patch/661/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

8922f79e

MIPS: Loongson 2F: Add CPU frequency scaling support · f8ede0f7

由 Wu Zhangjin 提交于 11月 17, 2009

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: NWu 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: NRalf Baechle <ralf@linux-mips.org>

f8ede0f7

MIPS: Add basic CPUFreq options. · 9726b43a

由 Wu Zhangjin 提交于 11月 17, 2009

This patch adds basic options for MIPS CPUFreq support.

Since the cp0 timer's frequency is based on the processor clockrate it can
not be used with CPUFReq; an additional external timer is required.
Signed-off-by: NWu 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/659/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

9726b43a

MIPS: Lemote 2F: Add cs5536 MFGPT timer support · 916daba8

由 Wu Zhangjin 提交于 11月 17, 2009

CPUFreq support for Loongson 2F requires an external timer.

Because the frequency of the MIPS Timer is related to the CPU frequency
which itself is variable another timer of constant frequency is required.

Export the mfgpt0 counter disable / enable operations for the coming
suspend support to suspend / resume the timer.
Signed-off-by: NWu 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/658/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

916daba8

MIPS: Lemote 2F: Add Lynloong support · 6e552c9b

由 Wu Zhangjin 提交于 11月 17, 2009

Add a new machtype and kernel options for the Lynloong.
Signed-off-by: NWu Zhangjin <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/657/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

6e552c9b

MIPS: Lemote 2F: Add NAS support · e13fb776

由 Wu Zhangjin 提交于 11月 17, 2009

Kernel support for this machine is almost the same as Fuloong 2F; the only
difference is that it uses the serial port provided by Loongson 2F processor
as Yeeloong 2F does.
Signed-off-by: NWu Zhangjin <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/656/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

e13fb776

MIPS: PowerTV: Base files for Cisco PowerTV platform · a3a0f8c8

由 David VomLehn 提交于 8月 30, 2009

Add the Cisco Powertv cable settop box to the MIPS tree. This platform is
based on a MIPS 24Kc processor with various devices integrated on the same
ASIC. There are multiple models of this box, with differing configuration
but the same kernel runs across the product line.
Signed-off-by: NDavid VomLehn <dvomlehn@cisco.com>
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/132/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

a3a0f8c8

MIPS: Sibyte: Use hweight8 instead of counting bits · 13e79b46

由 Akinobu Mita 提交于 11月 13, 2009

Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/637/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

13e79b46

MIPS: Yeeloong 2F: Add board specific suspend support · a9e8641f

由 Wu Zhangjin 提交于 11月 11, 2009

Lemote Loongson 2F family machines need an external interrupt to wake the
system from the suspend mode.

For YeeLoong 2F and Mengloong 2F setup the keyboard interrupt as the wakeup
interrupt.

The new Fuloong 2F and LingLoong 2F have a button to directly send an
interrupt to the CPU so there is no need to setup an interrupt.
Signed-off-by: NWu Zhangjin <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: yanh@lemote.com
Cc: huhb@lemote.com
Cc: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: linux-pm@lists.linux-foundation.org
Patchwork: http://patchwork.linux-mips.org/patch/630/Acked-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

a9e8641f

MIPS: Loongson 2F: Add suspend support framework · f181bf60

由 Wu Zhangjin 提交于 11月 11, 2009

This patch add basic suspend support for loongson2f family machines,
loongson2f have a specific feature: when we set it's frequency to ZERO,
it will go into a wait mode, and then can be waked up by the external
interrupt. so, if we setup suitable interrupts before putting it into
wait mode, we will be able wake it up whenever we want via sending the
relative interrupts to it.

These interrupts are board-specific, Yeeloong2F use the keyboard
interrupt and SCI interrupt, but LingLoong and Fuloong2F use the
interrupts connected to the processors directly. and BTW: some old
LingLoong and FuLoong2F have no such interrupts connected, so, there is
no way to wake them up from suspend mode. and therefore, please do not
enable the kernel support for them.

The board-specific support will be added in the coming patches.
Signed-off-by: NWu Zhangjin <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: yanh@lemote.com
Cc: huhb@lemote.com
Cc: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: linux-pm@lists.linux-foundation.org
Patchwork: http://patchwork.linux-mips.org/patch/629/Acked-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

f181bf60

MIPS: Add support for uncached accelerated mappings. · 22f1fdfd

由 Wu Zhangjin 提交于 11月 11, 2009

Loongson2f support video acceleration.
Signed-off-by: NWu Zhangjin <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/624/
Patchwork: http://patchwork.linux-mips.org/patch/625/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

22f1fdfd

MIPS: Loongson 2F: Cleanup the #if clauses · 55045ff5

由 Wu Zhangjin 提交于 11月 11, 2009

This patch adds two new kernel options: CPU_SUPPORTS_CPUFREQ and
CPU_SUPPORTS_ADDRWINCFG to describe the new features of Loongons 2F and
replaces the several ugly #if clauses by them.

These two options will be utilized by the future loongson revisions and
related drivers such as the coming Loongson 2F CPUFreq driver.
Signed-off-by: NWu Zhangjin <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: Wu Zhangjin <wuzhangjin@gmail.com>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

55045ff5

MIPS: Lemote 2F: Add defconfig file · 6e34358e