[PATCH v2 0/6] Add character devices for indices and platform-dump RTAS

[Haren Myneni <haren@linux.ibm.com>]

Several APIs such as rtas_get_indices(), rtas_get_dynamic_sensor(),
rtas_set_dynamic_indicator() and rtas_platform_dump() provided by
librtas library are implemented in user space using rtas syscall
in combination with writable mappings of /dev/mem. But this
implementation is not compatible with system lockdown which
prohibits /dev/mem access. The current kernel already provides
char based driver interfaces for several RTAS calls such as VPD
and system parameters to support lockdown feature.

This patch series adds new char based drivers, /dev/papr-indices
for ibm,get-indices, ibm,get-dynamic-sensor-state and
ibm,set-dynamic-indicator RTAS Calls. and /dev/papr-platform-dump
for ibm,platform-dump. Providing the similar open/ioctl/read
interfaces to the user space as in the case of VPD and system
parameters.

I have made changes to librtas library to use the new kernel
interfaces if the corresponding device entry is available.

This patch series has the following patches:
powerpc/pseries: Define common functions for RTAS sequence calls
- For some of sequence based RTAS calls, the OS should not start
  another sequence with different input until the previous sequence
  is completed. So the sequence should be completed during ioctl()
  and expose the entire buffer during read(). ibm,get-indices is
  sequence based RTAS function similar to ibm,get-vpd and we already
  have the corresponding implementation for VPD driver. So update
  papr_rtas_sequence struct for RTAS call specific functions and move
  the top level sequence functions in to a separate file.

powerpc/pseries: Define papr_indices_io_block for papr-indices ioctls
- /dev/papr-indices driver supports ibm,get-indices,
  ibm,get-dynamic-sensor-state and ibm,set-dynamic-indicator RTAS Calls.
  papr-indices.h introduces 3 different ioctls for these RTAS calls and
  the corresponding ioctl input buffer.

powerpc/pseries: Add papr-indices char driver for ibm,get-indices
- Introduce /dev/papr-indices char based driver and add support for
  get-indices RTAS function

powerpc/pseries: Add ibm,set-dynamic-indicator RTAS call support
- Update /dev/papr-indices for set-dynamic-indicator RTAS function

powerpc/pseries: Add ibm,get-dynamic-sensor-state RTAS call support
-  Update /dev/papr-indices for  get-dynamic-sensor-state RTAS function

powerpc/pseries: Add papr-platform-dump character driver for dump
   retrieval
- Introduce /dev/papr-platform-dump char driver and adds support for
  ibm,platform-dump. Received suggestions from the previous post as a
  separate patch - Updated the patch with invalidating the dump using
  a separate ioctl.

Changelog:

v2:
- Added unlock rtas_ibm_set_dynamic_indicator_lock and
  rtas_ibm_get_dynamic_sensor_state_lock mutex for failure cases
  as reported by Dan Carpenter
- Fixed build warnings for the proper function parameter descriptions
  as reported by kernel test robot <lkp@intel.com> 

Haren Myneni (6):
  powerpc/pseries: Define common functions for RTAS sequence calls
  powerpc/pseries: Define papr_indices_io_block for papr-indices ioctls
  powerpc/pseries: Add papr-indices char driver for ibm,get-indices
  powerpc/pseries: Add ibm,set-dynamic-indicator RTAS call support
  powerpc/pseries: Add ibm,get-dynamic-sensor-state RTAS call support
  powerpc/pseries: Add papr-platform-dump character driver for dump
    retrieval

 arch/powerpc/include/asm/rtas.h               |   3 +
 arch/powerpc/include/uapi/asm/papr-indices.h  |  41 ++
 .../include/uapi/asm/papr-platform-dump.h     |  15 +
 arch/powerpc/kernel/rtas.c                    |   6 +-
 arch/powerpc/platforms/pseries/Makefile       |   3 +-
 arch/powerpc/platforms/pseries/papr-indices.c | 558 ++++++++++++++++++
 .../platforms/pseries/papr-platform-dump.c    | 408 +++++++++++++
 .../platforms/pseries/papr-rtas-common.c      | 243 ++++++++
 .../platforms/pseries/papr-rtas-common.h      |  45 ++
 arch/powerpc/platforms/pseries/papr-vpd.c     | 270 ++-------
 10 files changed, 1364 insertions(+), 228 deletions(-)
 create mode 100644 arch/powerpc/include/uapi/asm/papr-indices.h
 create mode 100644 arch/powerpc/include/uapi/asm/papr-platform-dump.h
 create mode 100644 arch/powerpc/platforms/pseries/papr-indices.c
 create mode 100644 arch/powerpc/platforms/pseries/papr-platform-dump.c
 create mode 100644 arch/powerpc/platforms/pseries/papr-rtas-common.c
 create mode 100644 arch/powerpc/platforms/pseries/papr-rtas-common.h

-- 
2.43.5