History log of /arch/arm/kernel/etm.c
Revision Date Author Comments
75cbaea01019c02db84dfaebe631fc031433edb5 04-Apr-2012 Arve Hjønnevåg <arve@android.com> ARM: etm: Add sysfs entry to enable return stack if supported

Change-Id: Icb73d60324ad0ddfc3e8a450a28bb3d90c702788
Signed-off-by: Arve Hjønnevåg <arve@android.com>
434032a1dafba06192a6d769042c6fdac20784b2 04-Apr-2012 Arve Hjønnevåg <arve@android.com> ARM: etm: Add sysfs entry to disable branch_output flag

Change-Id: Ib91208a2c33621aa2d7bd9aa72bfbc670d9d5f1d
Signed-off-by: Arve Hjønnevåg <arve@android.com>
c6b1c35d885dc828e3554524b9fbecf59fa68e86 03-Apr-2012 Arve Hjønnevåg <arve@android.com> ARM: etm: Add sysfs entry to set context-id-size

Change-Id: I520dfb6e593dac131de8b9b1db77f1c734f18c24
Signed-off-by: Arve Hjønnevåg <arve@android.com>
cfb8dc5179c0d8ef0864c7a2441ec49772b63985 03-Apr-2012 Arve Hjønnevåg <arve@android.com> ARM: etm: Add sysfs entry to enable timestamps if supported

Change-Id: Iff964ba2f6236ed81863e02ec7b3ec9fbc48044a
Signed-off-by: Arve Hjønnevåg <arve@android.com>
d263bc79b2bd442d33611a5de3a1d4e302352a81 03-Apr-2012 Arve Hjønnevåg <arve@android.com> ARM: etm: Check arch version and disable data tracing for ptm

Change-Id: If2cb7928d0711f48348443d882a12416be9c5910
Signed-off-by: Arve Hjønnevåg <arve@android.com>
eff62a8af891cfdbe28c1abe28f42a9279bead87 29-Mar-2012 Arve Hjønnevåg <arve@android.com> ARM: etm: Wait for etm/ptm(s) to stop before requesting PowerDown

When PowerDown was requested at the same time as ProgBit, the
formatter flush command that follows could get stuck.

Change-Id: Iafb665f61f055819e64ca1dcb60398c656f593e4
Signed-off-by: Arve Hjønnevåg <arve@android.com>
424698382015fefdc0551f9d4c301dfe6504b193 24-Feb-2011 Arve Hjønnevåg <arve@android.com> ARM: etm: Power down etm(s) when tracing is not enabled

Without this change a saw an 18% increase in idle power consumption
on one deivce when trace support is compiled into the kernel. Now
I see the same increase only when tracing.

Change-Id: I21bb5ecf1b7d29ce3790ceeb5323409cc22d5a3b
Signed-off-by: Arve Hjønnevåg <arve@android.com>
992cd59960f613af65f0ecea49f3380fe7cb228f 05-Feb-2011 Arve Hjønnevåg <arve@android.com> ARM: etm: Support multiple ETMs/PTMs.

If more than one ETM or PTM are present, configure all of them
and enable the formatter in the ETB. This allows tracing on dual
core systems (e.g. omap4).

Change-Id: I028657d5cf2bee1b23f193d4387b607953b35888
Signed-off-by: Arve Hjønnevåg <arve@android.com>
3a91f3e567e77fb9ddabbbfe254b08f63f122a9d 05-Feb-2011 Arve Hjønnevåg <arve@android.com> ARM: etm: Return the entire trace buffer if it is empty after reset

On some SOCs the read and write pointer are reset when the chip
resets, but the trace buffer content is preserved. If the status
bits indicates that the buffer is empty and we have never started
tracing, assume the buffer is full instead. This can be useful
if the system rebooted from a watchdog reset.

Change-Id: Iaf21c2c329c6059004ee1d38e3dfff66d7d28029
Signed-off-by: Arve Hjønnevåg <arve@android.com>
fe05bda43174db16fe9e198f36228a4b405402dd 15-Feb-2011 Arve Hjønnevåg <arve@android.com> ARM: etm: Add some missing locks and error checks

It is not safe to call etm_lock or etb_lock without holding the
mutex since another thread may also have unlocked the registers.

Also add some missing checks for valid etb_regs in the etm sysfs
entries.

Change-Id: I939f76a6ea7546a8fc0d4ddafa2fd2b6f38103bb
Signed-off-by: Arve Hjønnevåg <arve@android.com>
0c3da535a0ed017ddeea0f3925a77150e3c5d7f8 01-Feb-2011 Arve Hjønnevåg <arve@android.com> ARM: etm: Configure data tracing

The old code enabled data tracing, but did not configure the
range. We now configure it to trace all data addresses by default,
and add a trace_data_range attribute to change the range or disable
data tracing.

Change-Id: I9d04e3e1ea0d0b4d4d5bcb93b1b042938ad738b2
Signed-off-by: Arve Hjønnevåg <arve@android.com>
d71c695d9ce253869e68bcee14c2674ce8f6da5b 29-Jan-2011 Arve Hjønnevåg <arve@android.com> ARM: etm: Allow range selection

Trace kernel text segment by default as before, allow tracing of other
ranges by writing a range to /sys/devices/etm/trace_range, or to trace
everything by writing 0 0.

Change-Id: Ibb734ca820fedf79560b20536247f1e1700cdc71
Signed-off-by: Arve Hjønnevåg <arve@android.com>
f13ae471a97f02ae16435dd1a5e274065904baac 01-Feb-2011 Arve Hjønnevåg <arve@android.com> ARM: etm: Don't try to clear the buffer full status after reading the buffer

If the write address was at the end of the buffer, toggling the trace
capture bit would set the RAM-full status instead of clearing it, and
if any of the stop bits in the formatter is set toggling the trace
capture bit may not do anything.

Instead use the read position to find out if the data has already
been returned.

This also fixes the read function so it works when the trace buffer is
larger than the buffer passed in from user space. The old version
would reset the trace buffer pointers after every read, so the second
call to read would always return 0.

Change-Id: I75256abe2556adfd66fd5963e46f9e84ae4645e1
Signed-off-by: Arve Hjønnevåg <arve@android.com>
8511b5bb64fe6c41ec258f499477e44ef2dca736 29-Jan-2011 Arve Hjønnevåg <arve@android.com> ARM: etm: Don't limit tracing to only non-secure code.

On some systems kernel code is considered secure, and this code
already limits tracing to the kernel text segment which results
in no trace data.

Change-Id: I098a0753e874859446d098e1ee209f67fc13cd5d
Signed-off-by: Arve Hjønnevåg <arve@android.com>
d38765986978391349c0c16dce69c1945c3dd2ad 29-Jan-2011 Arve Hjønnevåg <arve@android.com> ARM: etm: Don't require clock control

If clk_get fail, assume the etb does not need a separate clock.

Change-Id: Ia0bf3f5391e94a60ea45876aa7afc8a88a7ec3bf
Signed-off-by: Arve Hjønnevåg <arve@android.com>
73017a542fd2e92a02464eb8b727c200c97e6c0c 31-Jul-2011 Paul Gortmaker <paul.gortmaker@windriver.com> arm: fix implicit module.h users by adding it to arch/arm as required.

These files will fail to compile if we dont clean them up in advance
and have them include the appropriate headers they need.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
8e8806990cfd91a4ec25df6f00528008c4b0087a 28-Mar-2011 Ming Lei <tom.leiming@gmail.com> ARM: 6838/1: etm: fix section mismatch warning

The patch fixes the warning below:

WARNING: arch/arm/kernel/built-in.o(.data+0x27c): Section mismatch in reference from the variable etb_driver to the function .init.text:etb_probe()
The variable etb_driver references
the function __init etb_probe()
If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console,

WARNING: arch/arm/kernel/built-in.o(.data+0x2cc): Section mismatch in reference from the variable etm_driver to the function .init.text:etm_probe()
The variable etm_driver references
the function __init etm_probe()
If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console,

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
aa25afad2ca60d19457849ea75e9c31236f4e174 19-Feb-2011 Russell King <rmk+kernel@arm.linux.org.uk> ARM: amba: make probe() functions take const id tables

Make Primecell driver probe functions take a const pointer to their
ID tables. Drivers should never modify their ID tables in their
probe handler.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
6038f373a3dc1f1c26496e60b6c40b164716f07e 15-Aug-2010 Arnd Bergmann <arnd@arndb.de> llseek: automatically add .llseek fop

All file_operations should get a .llseek operation so we can make
nonseekable_open the default for future file operations without a
.llseek pointer.

The three cases that we can automatically detect are no_llseek, seq_lseek
and default_llseek. For cases where we can we can automatically prove that
the file offset is always ignored, we use noop_llseek, which maintains
the current behavior of not returning an error from a seek.

New drivers should normally not use noop_llseek but instead use no_llseek
and call nonseekable_open at open time. Existing drivers can be converted
to do the same when the maintainer knows for certain that no user code
relies on calling seek on the device file.

The generated code is often incorrectly indented and right now contains
comments that clarify for each added line why a specific variant was
chosen. In the version that gets submitted upstream, the comments will
be gone and I will manually fix the indentation, because there does not
seem to be a way to do that using coccinelle.

Some amount of new code is currently sitting in linux-next that should get
the same modifications, which I will do at the end of the merge window.

Many thanks to Julia Lawall for helping me learn to write a semantic
patch that does all this.

===== begin semantic patch =====
// This adds an llseek= method to all file operations,
// as a preparation for making no_llseek the default.
//
// The rules are
// - use no_llseek explicitly if we do nonseekable_open
// - use seq_lseek for sequential files
// - use default_llseek if we know we access f_pos
// - use noop_llseek if we know we don't access f_pos,
// but we still want to allow users to call lseek
//
@ open1 exists @
identifier nested_open;
@@
nested_open(...)
{
<+...
nonseekable_open(...)
...+>
}

@ open exists@
identifier open_f;
identifier i, f;
identifier open1.nested_open;
@@
int open_f(struct inode *i, struct file *f)
{
<+...
(
nonseekable_open(...)
|
nested_open(...)
)
...+>
}

@ read disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
<+...
(
*off = E
|
*off += E
|
func(..., off, ...)
|
E = *off
)
...+>
}

@ read_no_fpos disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
... when != off
}

@ write @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
<+...
(
*off = E
|
*off += E
|
func(..., off, ...)
|
E = *off
)
...+>
}

@ write_no_fpos @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
... when != off
}

@ fops0 @
identifier fops;
@@
struct file_operations fops = {
...
};

@ has_llseek depends on fops0 @
identifier fops0.fops;
identifier llseek_f;
@@
struct file_operations fops = {
...
.llseek = llseek_f,
...
};

@ has_read depends on fops0 @
identifier fops0.fops;
identifier read_f;
@@
struct file_operations fops = {
...
.read = read_f,
...
};

@ has_write depends on fops0 @
identifier fops0.fops;
identifier write_f;
@@
struct file_operations fops = {
...
.write = write_f,
...
};

@ has_open depends on fops0 @
identifier fops0.fops;
identifier open_f;
@@
struct file_operations fops = {
...
.open = open_f,
...
};

// use no_llseek if we call nonseekable_open
////////////////////////////////////////////
@ nonseekable1 depends on !has_llseek && has_open @
identifier fops0.fops;
identifier nso ~= "nonseekable_open";
@@
struct file_operations fops = {
... .open = nso, ...
+.llseek = no_llseek, /* nonseekable */
};

@ nonseekable2 depends on !has_llseek @
identifier fops0.fops;
identifier open.open_f;
@@
struct file_operations fops = {
... .open = open_f, ...
+.llseek = no_llseek, /* open uses nonseekable */
};

// use seq_lseek for sequential files
/////////////////////////////////////
@ seq depends on !has_llseek @
identifier fops0.fops;
identifier sr ~= "seq_read";
@@
struct file_operations fops = {
... .read = sr, ...
+.llseek = seq_lseek, /* we have seq_read */
};

// use default_llseek if there is a readdir
///////////////////////////////////////////
@ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier readdir_e;
@@
// any other fop is used that changes pos
struct file_operations fops = {
... .readdir = readdir_e, ...
+.llseek = default_llseek, /* readdir is present */
};

// use default_llseek if at least one of read/write touches f_pos
/////////////////////////////////////////////////////////////////
@ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read.read_f;
@@
// read fops use offset
struct file_operations fops = {
... .read = read_f, ...
+.llseek = default_llseek, /* read accesses f_pos */
};

@ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write.write_f;
@@
// write fops use offset
struct file_operations fops = {
... .write = write_f, ...
+ .llseek = default_llseek, /* write accesses f_pos */
};

// Use noop_llseek if neither read nor write accesses f_pos
///////////////////////////////////////////////////////////

@ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
identifier write_no_fpos.write_f;
@@
// write fops use offset
struct file_operations fops = {
...
.write = write_f,
.read = read_f,
...
+.llseek = noop_llseek, /* read and write both use no f_pos */
};

@ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write_no_fpos.write_f;
@@
struct file_operations fops = {
... .write = write_f, ...
+.llseek = noop_llseek, /* write uses no f_pos */
};

@ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
@@
struct file_operations fops = {
... .read = read_f, ...
+.llseek = noop_llseek, /* read uses no f_pos */
};

@ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
@@
struct file_operations fops = {
...
+.llseek = noop_llseek, /* no read or write fn */
};
===== End semantic patch =====

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Julia Lawall <julia@diku.dk>
Cc: Christoph Hellwig <hch@infradead.org>
8234eaef8002cb8ba30920949b338d692508137a 04-Aug-2010 Alexander Shishkin <virtuoso@slind.org> ARM: 6291/1: coresight: move struct tracectx inside etm driver

This is done so as to be able to make use of the coresight components'
registers in assembler code (like omap sleep code). Also, there shouldn't
be any users of this structure outside the etm driver.

Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Alexander Shishkin <virtuoso@slind.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
1495cc9df4e81f5a8fa9b0b8f1034b14d24b7d8c 18-Aug-2010 Dmitry Torokhov <dmitry.torokhov@gmail.com> Input: sysrq - drop tty argument from sysrq ops handlers

Noone is using tty argument so let's get rid of it.

Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Acked-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
988257cfcbc468cb26b3addfcab1d0187c4e2399 04-Aug-2010 Alexander Shishkin <virtuoso@slind.org> ARM: 6294/1: etm: do a dummy read from OSSRR during initialization

The first read from ETM OS save and restore register after the power
down bit deassertion returns garbage.

Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Alexander Shishkin <virtuoso@slind.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
9e354ea8e0710baf05804168fdabe90231b3d363 04-Aug-2010 Alexander Shishkin <virtuoso@slind.org> ARM: 6292/1: coresight: add ETM management registers

Add notion of ETM OS lock, save and restore registers.

Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Alexander Shishkin <virtuoso@slind.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
c5d6c7708c3e58015b2e4e13e6cea02c8567a94e 01-Dec-2009 Alexander Shishkin <virtuoso@slind.org> ARM: 5841/1: a driver for on-chip ETM and ETB

This driver implements support for on-chip Embedded Tracing Macrocell and
Embedded Trace Buffer. It allows to trigger tracing of kernel execution flow
and exporting trace output to userspace via character device and a sysrq
combo.

Trace output can then be decoded by a fairly simple open source tool [1]
which is already sufficient to get the idea of what the kernel is doing.

[1]: http://github.com/virtuoso/etm2human

Signed-off-by: Alexander Shishkin <virtuoso@slind.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>