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 <l...@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