From b3d627a5f2bf1a9a486f65af6f7c2ce0e09b3d12 Mon Sep 17 00:00:00 2001 From: Vaidyanathan Srinivasan Date: Tue, 1 Apr 2014 12:43:26 +0530 Subject: cpufreq: powernv: cpufreq driver for powernv platform Backend driver to dynamically set voltage and frequency on IBM POWER non-virtualized platforms. Power management SPRs are used to set the required PState. This driver works in conjunction with cpufreq governors like 'ondemand' to provide a demand based frequency and voltage setting on IBM POWER non-virtualized platforms. PState table is obtained from OPAL v3 firmware through device tree. powernv_cpufreq back-end driver would parse the relevant device-tree nodes and initialise the cpufreq subsystem on powernv platform. The code was originally written by svaidy@linux.vnet.ibm.com. Over time it was modified to accomodate bug-fixes as well as updates to the the cpu-freq core. Relevant portions of the change logs corresponding to those modifications are noted below: * The policy->cpus needs to be populated in a hotplug-invariant manner instead of using cpu_sibling_mask() which varies with cpu-hotplug. This is because the cpufreq core code copies this content into policy->related_cpus mask which should not vary on cpu-hotplug. [Authored by srivatsa.bhat@linux.vnet.ibm.com] * Create a helper routine that can return the cpu-frequency for the corresponding pstate_id. Also, cache the values of the pstate_max, pstate_min and pstate_nominal and nr_pstates in a static structure so that they can be reused in the future to perform any validations. [Authored by ego@linux.vnet.ibm.com] * Create a driver attribute named cpuinfo_nominal_freq which creates a sysfs read-only file named cpuinfo_nominal_freq. Export the frequency corresponding to the nominal_pstate through this interface. Nominal frequency is the highest non-turbo frequency for the platform. This is generally used for setting governor policies from user space for optimal energy efficiency. [Authored by ego@linux.vnet.ibm.com] * Implement a powernv_cpufreq_get(unsigned int cpu) method which will return the current operating frequency. Export this via the sysfs interface cpuinfo_cur_freq by setting powernv_cpufreq_driver.get to powernv_cpufreq_get(). [Authored by ego@linux.vnet.ibm.com] [Change log updated by ego@linux.vnet.ibm.com] Reviewed-by: Preeti U Murthy Signed-off-by: Vaidyanathan Srinivasan Signed-off-by: Srivatsa S. Bhat Signed-off-by: Anton Blanchard Signed-off-by: Gautham R. Shenoy Signed-off-by: Rafael J. Wysocki --- arch/powerpc/include/asm/reg.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'arch/powerpc') diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h index 1a36b8ede417..2189f8f2ca88 100644 --- a/arch/powerpc/include/asm/reg.h +++ b/arch/powerpc/include/asm/reg.h @@ -271,6 +271,10 @@ #define SPRN_HSRR1 0x13B /* Hypervisor Save/Restore 1 */ #define SPRN_IC 0x350 /* Virtual Instruction Count */ #define SPRN_VTB 0x351 /* Virtual Time Base */ +#define SPRN_PMICR 0x354 /* Power Management Idle Control Reg */ +#define SPRN_PMSR 0x355 /* Power Management Status Reg */ +#define SPRN_PMCR 0x374 /* Power Management Control Register */ + /* HFSCR and FSCR bit numbers are the same */ #define FSCR_TAR_LG 8 /* Enable Target Address Register */ #define FSCR_EBB_LG 7 /* Enable Event Based Branching */ -- cgit v1.2.3-70-g09d2 From 81f359027a3a383cc1dc79499ce97f1074861e5b Mon Sep 17 00:00:00 2001 From: "Gautham R. Shenoy" Date: Tue, 1 Apr 2014 12:43:28 +0530 Subject: cpufreq: powernv: Select CPUFreq related Kconfig options for powernv Enable CPUFreq for PowerNV. Select "performance", "powersave", "userspace" and "ondemand" governors. Choose "ondemand" to be the default governor. Signed-off-by: Srivatsa S. Bhat Signed-off-by: Gautham R. Shenoy Signed-off-by: Rafael J. Wysocki --- arch/powerpc/configs/pseries_defconfig | 1 + arch/powerpc/configs/pseries_le_defconfig | 1 + arch/powerpc/platforms/powernv/Kconfig | 6 ++++++ 3 files changed, 8 insertions(+) (limited to 'arch/powerpc') diff --git a/arch/powerpc/configs/pseries_defconfig b/arch/powerpc/configs/pseries_defconfig index 9ea8342bd219..a905063281cc 100644 --- a/arch/powerpc/configs/pseries_defconfig +++ b/arch/powerpc/configs/pseries_defconfig @@ -306,3 +306,4 @@ CONFIG_KVM_BOOK3S_64=m CONFIG_KVM_BOOK3S_64_HV=y CONFIG_TRANSPARENT_HUGEPAGE=y CONFIG_TRANSPARENT_HUGEPAGE_ALWAYS=y +CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND=y diff --git a/arch/powerpc/configs/pseries_le_defconfig b/arch/powerpc/configs/pseries_le_defconfig index 3c84f9d87980..58e3dbf43ca4 100644 --- a/arch/powerpc/configs/pseries_le_defconfig +++ b/arch/powerpc/configs/pseries_le_defconfig @@ -301,3 +301,4 @@ CONFIG_CRYPTO_LZO=m # CONFIG_CRYPTO_ANSI_CPRNG is not set CONFIG_CRYPTO_DEV_NX=y CONFIG_CRYPTO_DEV_NX_ENCRYPT=m +CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND=y diff --git a/arch/powerpc/platforms/powernv/Kconfig b/arch/powerpc/platforms/powernv/Kconfig index 895e8a20a3fc..c252ee95bddf 100644 --- a/arch/powerpc/platforms/powernv/Kconfig +++ b/arch/powerpc/platforms/powernv/Kconfig @@ -11,6 +11,12 @@ config PPC_POWERNV select PPC_UDBG_16550 select PPC_SCOM select ARCH_RANDOM + select CPU_FREQ + select CPU_FREQ_GOV_PERFORMANCE + select CPU_FREQ_GOV_POWERSAVE + select CPU_FREQ_GOV_USERSPACE + select CPU_FREQ_GOV_ONDEMAND + select CPU_FREQ_GOV_CONSERVATIVE default y config PPC_POWERNV_RTAS -- cgit v1.2.3-70-g09d2