This patch is a v2 of a previous posting: http://lists.infradead.org/pipermail/linux-arm-kernel/2015-March/328192.html v1 -> v2: - Rebased against 4.0 - Removed DT affinity probe interface - Improved and optimized idle states comparison and cpumask creation - Merged DT idle states vetting code in the ARM CPUidle driver This patch aims at enabling the generic CPUidle driver on ARM systems with heterogeneous idle states. In the CPUidle context the kernel considers cpus equal (and group them together through a CPUidle driver) if they share the same set of idle states. Since the idle states represent the differentiation point when it comes to creating CPUidle drivers (their states and related cpu logical mask), the idle states can be used as a means to create logical masks of cpus for which the CPUidle driver applies. This patch sets the maximum number of static CPUidle drivers allowed to two, since it is hard to foresee systems with more than two sets of CPUs having different idle states; it is meant to keep allocation simple while keeping functionality. The code carrying out idle states comparison is completely generic and borrowed from OF unit tests; it overrides the OF API entirely though to carry out properties (ie phandles list) comparison in the fastest possible way. If deemed worthwhile it can be moved to generic OF layer. Tested through several dts idle states permutations on Juno board with CPUidle and related idle states enabled. Cc: Howard Chen <howard.chen@xxxxxxxxxx> Cc: Rob Herring <robh+dt@xxxxxxxxxx> Cc: Kevin Hilman <khilman@xxxxxxxxxx> Cc: Sudeep Holla <sudeep.holla@xxxxxxx> Cc: Lina Iyer <lina.iyer@xxxxxxxxxx> Cc: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx> Cc: Grant Likely <grant.likely@xxxxxxxxxx> Cc: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx> Cc: Mark Rutland <mark.rutland@xxxxxxx> Lorenzo Pieralisi (1): drivers: cpuidle: cpuidle-arm: heterogeneous systems extension drivers/cpuidle/Kconfig.arm | 1 + drivers/cpuidle/cpuidle-arm.c | 176 ++++++++++++++++++++++++++++++++++++------ 2 files changed, 152 insertions(+), 25 deletions(-) -- 2.2.1 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
