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  1. 17 Jan, 2018 1 commit
    • Sudeep Holla's avatar
      drivers: psci: remove cluster terminology and dependency on physical_package_id · dff4113d
      Sudeep Holla authored 
      Since the definition of the term "cluster" is not well defined in the
architecture, we should avoid using it. Also the physical package id
is currently mapped to so called "clusters" in ARM/ARM64 platforms which
is already argumentative.

Currently PSCI checker uses the physical package id assuming that CPU
power domains map to "clusters" and the physical package id in the code
as it stands also maps to cluster boundaries. It does that trying to
test "cluster" idle states to its best. However the CPU power domain
often but not always maps directly to the processor topology.

This patch removes the dependency on physical_package_id from the topology
in this PSCI checker. Also it replaces all the occurences of clusters to
cpu_groups which is derived from core_sibling_mask and may not directly
map to physical "cluster".
Acked-by: default avatarLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: default avatarSudeep Holla <sudeep.holla@arm.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
      dff4113d
  3. 12 Jan, 2018 1 commit
  5. 11 Jan, 2018 2 commits
  7. 10 Jan, 2018 2 commits
  9. 05 Jan, 2018 4 commits
    • Viresh Kumar's avatar
      cpufreq: stats: Change return type of cpufreq_stats_update() as void · d476ec4f
      Viresh Kumar authored 
      It always returns 0 and none of its callers check its return value. Make
it return void.
Signed-off-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
      d476ec4f
    • Gautham R. Shenoy's avatar
      powernv-cpufreq: Treat pstates as opaque 8-bit values · 967b87fd
      Gautham R. Shenoy authored 
      On POWER8 and POWER9, the PMSR and the PMCR registers define pstates
to be 8-bit wide values. The device-tree exports pstates as 32-bit
wide values of which the lower byte is the actual pstate.

The current implementation in the kernel treats pstates as integer
type, since it used to use the sign of the pstate for performing some
boundary-checks. This is no longer required after the patch
"powernv-cpufreq: Fix pstate_to_idx() to handle non-continguous
pstates".

So, in this patch, we modify the powernv-cpufreq driver to uniformly
treat pstates as opaque 8-bit values obtained from the device-tree or
the PMCR. This simplifies the extract_pstate() helper function since
we no longer no longer require to worry about the sign-extentions.
Signed-off-by: default avatarGautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
      967b87fd
    • Gautham R. Shenoy's avatar
      powernv-cpufreq: Fix pstate_to_idx() to handle non-continguous pstates · 332f0a01
      Gautham R. Shenoy authored 
      The code in powernv-cpufreq, makes the following two assumptions which
are not guaranteed by the device-tree bindings:

    1) Pstate ids are continguous: This is used in pstate_to_idx() to
       obtain the reverse map from a pstate to it's corresponding
       entry into the cpufreq frequency table.

    2) Every Pstate should always lie between the max and the min
       pstates that are explicitly reported in the device tree: This
       is used to determine whether a pstate reported by the PMSR is
       out of bounds.

Both these assumptions are unwarranted and can change on future
platforms.

In this patch, we maintain the reverse map from a pstate to it's index
in the cpufreq frequency table and use this in pstate_to_idx(). This
does away with the assumptions (1) mentioned above, and will work with
non continguous pstate ids. If no entry exists for a particular
pstate, then such a pstate is treated as being out of bounds. This
gets rid of assumption (2).

On all the existing platforms, where the pstates are 8-bit long
values, the new implementation of pstate_to_idx() takes constant time.
Signed-off-by: default avatarGautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
      332f0a01
    • Gautham R. Shenoy's avatar
      powernv-cpufreq: Add helper to extract pstate from PMSR · ee1f4a7d
      Gautham R. Shenoy authored 
      On POWERNV platform, the fields for pstates in the Power Management
Status Register (PMSR) and the Power Management Control Register
(PMCR) are 8-bits wide. On POWER8 the pstates are negatively numbered
while on POWER9 they are positively numbered.

The device-tree exports pstates as 32-bit entries. The device-tree
implementation sign-extends the 8-bit pstate values to obtain the
corresponding 32-bit entry.

Eg: On POWER8, a pstate value 0x82 [-126] is represented in the
device-tree as 0xfffffff82 while on POWER9, the same value 0x82 [130]
is represented in the device-tree as 0x00000082.

The powernv-cpufreq driver implementation represents pstates using the
integer type. In multiple places in the driver, the code interprets
the pstates extracted from the PMSR as a signed byte and assigns it to
a integer variable to get the sign-extention.

On POWER9 platforms which have greater than 128 pstates, this results
in the driver performing incorrect sign-extention, and thereby
treating a legitimate pstate (say 130) as an invalid pstates (since it
is interpreted as -126).

This patch fixes the issue by implementing a helper function to
extract Pstates from PMSR register, and correctly sign-extend it to be
consistent with the values provided by the device-tree.
Signed-off-by: default avatarGautham R. Shenoy <ego@linux.vnet.ibm.com>
Acked-by: default avatarBalbir Singh <bsingharora@gmail.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
      ee1f4a7d
  11. 28 Dec, 2017 2 commits
  13. 21 Dec, 2017 1 commit
  15. 18 Dec, 2017 3 commits
  17. 17 Dec, 2017 24 commits
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