linux.git/arch/powerpc/kernel/sysfs.c, branch v2.6.30

powerpc: Fix bugs introduced by sysfs changes

2009-03-27T05:58:24+00:00

Rusty's patch to change our sysfs access to various registers
to use smp_call_function_single() introduced a whole bunch of
warnings. This fixes them. This version also fixes an actual
bug in here where it did mtspr instead of mfspr when reading
the files

Signed-off-by: Benjamin Herrenschmidt

powerpc: Make sysfs code use smp_call_function_single

2009-03-24T02:47:27+00:00

Impact: performance improvement

This fixes 'powerpc: avoid cpumask games in arch/powerpc/kernel/sysfs.c'
which talked about using smp_call_function_single, but actually used
work_on_cpu (an older version of the patch).

Signed-off-by: Rusty Russell 
Signed-off-by: Benjamin Herrenschmidt

powerpc: Rewrite sysfs processor cache info code

2009-01-08T05:25:10+00:00

The current code for providing processor cache information in sysfs
has the following deficiencies:
- several complex functions that are hard to understand
- implicit recursion (cache_desc_release -> kobject_put -> cache_desc_release)
- explicit recursion (create_cache_index_info)
- use of two per-cpu arrays when one would suffice
- duplication of work on systems where CPUs share cache

Also, when I looked at implementing support for a shared_cpu_map
attribute, it was pretty much impossible to handle hotplug without
checking every single online CPU's cache_desc list and fixing things
up... not that this is a hot path, but it would have introduced
O(n^2)-ish behavior during boot.  Addressing this involved rethinking
the core data structures used, which didn't lend itself to an
incremental approach.

This implementation maintains a "forest" (potentially more than one
tree) of cache objects which reflects the system's cache topology.
Cache objects are instantiated as needed as CPUs come online.  A
per-cpu array is used mainly for sysfs-related bookkeeping; the
objects in the array just point to the appropriate points in the
forest.

This maintains compatibility with the existing code and includes some
enhancements:
- Implement the shared_cpu_map attribute, which is essential for
  enabling userspace to discover the system's overall cache topology.
- Use cache-block-size properties if cache-line-size is not available.

I chose to place this implementation in a new file since it would have
roughly doubled the size of sysfs.c, which is already kind of messy.

Signed-off-by: Nathan Lynch 
Signed-off-by: Benjamin Herrenschmidt

powerpc: Convert sysfs cache code to of_find_next_cache_node()

2008-12-21T03:21:14+00:00

Using the common code means that more complete cache information will
provided in sysfs on platforms that don't use the l2-cache property
convention.

Signed-off-by: Nathan Lynch 
Signed-off-by: Paul Mackerras

powerpc: Fix build for 32-bit SMP configs

2008-12-01T02:28:19+00:00

attr_smt_snooze_delay is only defined for CONFIG_PPC64, so protect the
attribute removal with the same condition.  This fixes this build error
on 32-bit SMP configurations:

/data/home/miltonm/next.git/arch/powerpc/kernel/sysfs.c: In function ‘unregister_cpu_online’:
/data/home/miltonm/next.git/arch/powerpc/kernel/sysfs.c:722: error: ‘attr_smt_snooze_delay’ undeclared (first use in this function)
/data/home/miltonm/next.git/arch/powerpc/kernel/sysfs.c:722: error: (Each undeclared identifier is reported only once
/data/home/miltonm/next.git/arch/powerpc/kernel/sysfs.c:722: error: for each function it appears in.)

Signed-off-by: Paul Mackerras

powerpc: Fix build warnings introduced by PMC support on 32-bit

2008-09-18T22:57:50+00:00

arch/powerpc/kernel/sysfs.c:197:7: warning: "CONFIG_6xx" is not defined
arch/powerpc/kernel/sysfs.c:141: warning: 'run_on_cpu' defined but not used

Signed-off-by: Kumar Gala

powerpc: Expose PMCs & cache topology in sysfs on 32-bit

2008-08-20T06:34:58+00:00

The file arch/powerpc/kernel/sysfs.c is currently only compiled for
64-bit kernels.  It contain code to register CPU sysdevs in sysfs and
add various properties such as cache topology and raw access by root
to performance monitor counters (PMCs).  A lot of that can be re-used
as is on 32-bits.

This makes the file be built for both, with appropriate ifdef'ing
for the few bits that are really 64-bit specific, and adds some
support for the raw PMCs for 75x and 74xx processors.

Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Paul Mackerras

powerpc: Remove redundant sysfs_remove_file calls for cache info

2008-08-20T06:34:58+00:00

When removing a directory, the sysfs core takes care of removing files
in the directory (see sysfs_remove_dir()).  So when we are about to
delete a kobject (and thus cause its sysfs directory to be removed),
we don't have to explicitly remove the files attached to it, although
it's harmless to do so.

Signed-off-by: Nathan Lynch 
Signed-off-by: Paul Mackerras

powerpc: Show processor cache information in sysfs

2008-07-28T06:30:52+00:00

Collect cache information from the OF device tree and display it in
the cpu hierarchy in sysfs.  This is intended to be compatible at the
userspace level with x86's implementation[1], hence some of the funny
attribute names.  The arrangement of cache info is not immediately
intuitive, but (again) it's for compatibility's sake.

The cache attributes exposed are:

type (Data, Instruction, or Unified)
level (1, 2, 3...)
size
coherency_line_size
number_of_sets
ways_of_associativity

All of these can be derived on platforms that follow the OF PowerPC
Processor binding.  The code "publishes" only those attributes for
which it is able to determine values; attributes for values which
cannot be determined are not created at all.

[1] arch/x86/kernel/cpu/intel_cacheinfo.c

BenH: Turned some printk's into pr_debug, added better NULL checking
in a couple of places.

Signed-off-by: Nathan Lynch 
Signed-off-by: Benjamin Herrenschmidt

powerpc: register_cpu_online should be __cpuinit

2008-07-28T06:30:48+00:00

It is called only in cpu online paths.

(caught by CONFIG_DEBUG_SECTION_MISMATCH=y)

Signed-off-by: Nathan Lynch 
Signed-off-by: Benjamin Herrenschmidt