[PATCH v5 0/3] powernv,cpufreq: Dynamic Frequency Scaling support

[PATCH v5 0/3] powernv,cpufreq: Dynamic Frequency Scaling support

[Gautham R. Shenoy]

From: "Gautham R. Shenoy" <ego@linux.vnet.ibm.com>

Hi,

This is v5 of the patchset to enable dynamic frequency scaling on IBM
PowerNV platforms. This patchset does address all the review comments
obtained for v4 (which can be found at [1]).

Changes from v4:

    * Created a separate patch to select the CPUFreq related Config
      options for PowerNV

    * Dropped the per-core locking hunks in
      drivers/cpufreq/powernv-cpufreq.c since the CPUFreq core takes
      care of the for us after the following commit which is present in
      linux-next:

	commit 12478cf0c55e5969f740bb38a24b1a0104ae18d8	  
      	Author: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
        Date:   Mon Mar 24 13:35:44 2014 +0530

       	cpufreq: Make sure frequency transitions are serialized

    * [PATCH v5 3/3] gets rid of the powernv_pstate_ids[] array that
      was being used to record the pstate ids. After the following
      patch it is safe to use cpufreq_frequency_table.driver_data
      since it is opaque to the cpufreq core: 

      	From: Viresh Kumar <viresh.kumar@linaro.org>
	Date: 2014-03-28 13:53:47
	url: http://marc.info/?l=linux-pm&m=139601416804702&w=2
	    
	cpufreq: create another field .flags in cpufreq_frequency_table

The patchset is based on the commit
201544be8c37dffbf069bb5fc9edb5674f8c1754 of the linux-next tree.

While all the patches in the patchset apply cleanly on linux-next,
[PATCH v5 3/3] requires the Viresh's patch that was mentioned
above. Otherwise, the frequency corresponding to pstate id -3 will be
omited while reporting the "scaling_available_frequencies" in sysfs.

[1]: http://marc.info/?l=linux-pm&m=139585297620612&w=2

Gautham R. Shenoy (2):
  powernv, cpufreq: Select CPUFreq related Kconfig options for powernv
  powernv,cpufreq: Use cpufreq_frequency_table.driver_data to store
    pstate ids

Vaidyanathan Srinivasan (1):
  powernv, cpufreq: cpufreq driver for powernv platform

 arch/powerpc/configs/pseries_defconfig    |   1 +
 arch/powerpc/configs/pseries_le_defconfig |   1 +
 arch/powerpc/include/asm/reg.h            |   4 +
 arch/powerpc/platforms/powernv/Kconfig    |   6 +
 drivers/cpufreq/Kconfig.powerpc           |   8 +
 drivers/cpufreq/Makefile                  |   1 +
 drivers/cpufreq/powernv-cpufreq.c         | 341 ++++++++++++++++++++++++++++++
 7 files changed, 362 insertions(+)
 create mode 100644 drivers/cpufreq/powernv-cpufreq.c

-- 
1.8.3.1

[PATCH v5 1/3] powernv, cpufreq: Select CPUFreq related Kconfig options for powernv

[Gautham R. Shenoy]

From: "Gautham R. Shenoy" <ego@linux.vnet.ibm.com>

Enable CPUFreq for PowerNV. Select "performance", "powersave",
"userspace" and "ondemand" governors. Choose "ondemand" to be the
default governor.

Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
---
 arch/powerpc/configs/pseries_defconfig    | 1 +
 arch/powerpc/configs/pseries_le_defconfig | 1 +
 arch/powerpc/platforms/powernv/Kconfig    | 6 ++++++
 3 files changed, 8 insertions(+)

diff --git a/arch/powerpc/configs/pseries_defconfig b/arch/powerpc/configs/pseries_defconfig
index 9ea8342b..a905063 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 3c84f9d..58e3dbf 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 895e8a2..c252ee9 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
-- 
1.8.3.1

Re: [PATCH v5 1/3] powernv, cpufreq: Select CPUFreq related Kconfig options for powernv

[Viresh Kumar]

On 29 March 2014 01:41, Gautham R. Shenoy <ego@linux.vnet.ibm.com> wrote:
> From: "Gautham R. Shenoy" <ego@linux.vnet.ibm.com>
>
> Enable CPUFreq for PowerNV. Select "performance", "powersave",
> "userspace" and "ondemand" governors. Choose "ondemand" to be the
> default governor.
>
> Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
> ---
>  arch/powerpc/configs/pseries_defconfig    | 1 +
>  arch/powerpc/configs/pseries_le_defconfig | 1 +
>  arch/powerpc/platforms/powernv/Kconfig    | 6 ++++++
>  3 files changed, 8 insertions(+)

Probably it doesn't make much sense to keep this as the first patch
as you still don't have the driver available yet.

[PATCH v5 2/3] powernv, cpufreq: cpufreq driver for powernv platform

[Gautham R. Shenoy]

From: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>

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 <preeti@linux.vnet.ibm.com>
Signed-off-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/reg.h    |   4 +
 drivers/cpufreq/Kconfig.powerpc   |   8 +
 drivers/cpufreq/Makefile          |   1 +
 drivers/cpufreq/powernv-cpufreq.c | 342 ++++++++++++++++++++++++++++++++++++++
 4 files changed, 355 insertions(+)
 create mode 100644 drivers/cpufreq/powernv-cpufreq.c

diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index 1a36b8e..2189f8f 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 */
diff --git a/drivers/cpufreq/Kconfig.powerpc b/drivers/cpufreq/Kconfig.powerpc
index ca0021a..72564b7 100644
--- a/drivers/cpufreq/Kconfig.powerpc
+++ b/drivers/cpufreq/Kconfig.powerpc
@@ -54,3 +54,11 @@ config PPC_PASEMI_CPUFREQ
 	help
 	  This adds the support for frequency switching on PA Semi
 	  PWRficient processors.
+
+config POWERNV_CPUFREQ
+       tristate "CPU frequency scaling for IBM POWERNV platform"
+       depends on PPC_POWERNV
+       default y
+       help
+	 This adds support for CPU frequency switching on IBM POWERNV
+	 platform
diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
index 7494565..0dbb963 100644
--- a/drivers/cpufreq/Makefile
+++ b/drivers/cpufreq/Makefile
@@ -86,6 +86,7 @@ obj-$(CONFIG_PPC_CORENET_CPUFREQ)   += ppc-corenet-cpufreq.o
 obj-$(CONFIG_CPU_FREQ_PMAC)		+= pmac32-cpufreq.o
 obj-$(CONFIG_CPU_FREQ_PMAC64)		+= pmac64-cpufreq.o
 obj-$(CONFIG_PPC_PASEMI_CPUFREQ)	+= pasemi-cpufreq.o
+obj-$(CONFIG_POWERNV_CPUFREQ)		+= powernv-cpufreq.o
 
 ##################################################################################
 # Other platform drivers
diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c
new file mode 100644
index 0000000..e1e5197
--- /dev/null
+++ b/drivers/cpufreq/powernv-cpufreq.c
@@ -0,0 +1,342 @@
+/*
+ * POWERNV cpufreq driver for the IBM POWER processors
+ *
+ * (C) Copyright IBM 2014
+ *
+ * Author: Vaidyanathan Srinivasan <svaidy at linux.vnet.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#define pr_fmt(fmt)	"powernv-cpufreq: " fmt
+
+#include <linux/kernel.h>
+#include <linux/sysfs.h>
+#include <linux/cpumask.h>
+#include <linux/module.h>
+#include <linux/cpufreq.h>
+#include <linux/smp.h>
+#include <linux/of.h>
+
+#include <asm/cputhreads.h>
+#include <asm/reg.h>
+
+#define POWERNV_MAX_PSTATES	256
+
+static struct cpufreq_frequency_table powernv_freqs[POWERNV_MAX_PSTATES+1];
+static int powernv_pstate_ids[POWERNV_MAX_PSTATES+1];
+
+/*
+ * Note: The set of pstates consists of contiguous integers, the
+ * smallest of which is indicated by powernv_pstate_info.min, the
+ * largest of which is indicated by powernv_pstate_info.max.
+ *
+ * The nominal pstate is the highest non-turbo pstate in this
+ * platform. This is indicated by powernv_pstate_info.nominal.
+ */
+static struct powernv_pstate_info {
+	int min;
+	int max;
+	int nominal;
+	int nr_pstates;
+} powernv_pstate_info;
+
+/*
+ * Initialize the freq table based on data obtained
+ * from the firmware passed via device-tree
+ */
+static int init_powernv_pstates(void)
+{
+	struct device_node *power_mgt;
+	int i, pstate_min, pstate_max, pstate_nominal, nr_pstates = 0;
+	const __be32 *pstate_ids, *pstate_freqs;
+	u32 len_ids, len_freqs;
+
+	power_mgt = of_find_node_by_path("/ibm,opal/power-mgt");
+	if (!power_mgt) {
+		pr_warn("power-mgt node not found\n");
+		return -ENODEV;
+	}
+
+	if (of_property_read_u32(power_mgt, "ibm,pstate-min", &pstate_min)) {
+		pr_warn("ibm,pstate-min node not found\n");
+		return -ENODEV;
+	}
+
+	if (of_property_read_u32(power_mgt, "ibm,pstate-max", &pstate_max)) {
+		pr_warn("ibm,pstate-max node not found\n");
+		return -ENODEV;
+	}
+
+	if (of_property_read_u32(power_mgt, "ibm,pstate-nominal",
+				 &pstate_nominal)) {
+		pr_warn("ibm,pstate-nominal not found\n");
+		return -ENODEV;
+	}
+	pr_info("cpufreq pstate min %d nominal %d max %d\n", pstate_min,
+		pstate_nominal, pstate_max);
+
+	pstate_ids = of_get_property(power_mgt, "ibm,pstate-ids", &len_ids);
+	if (!pstate_ids) {
+		pr_warn("ibm,pstate-ids not found\n");
+		return -ENODEV;
+	}
+
+	pstate_freqs = of_get_property(power_mgt, "ibm,pstate-frequencies-mhz",
+				      &len_freqs);
+	if (!pstate_freqs) {
+		pr_warn("ibm,pstate-frequencies-mhz not found\n");
+		return -ENODEV;
+	}
+
+	WARN_ON(len_ids != len_freqs);
+	nr_pstates = min(len_ids, len_freqs) / sizeof(u32);
+	if (!nr_pstates) {
+		pr_warn("No PStates found\n");
+		return -ENODEV;
+	}
+
+	pr_debug("NR PStates %d\n", nr_pstates);
+	for (i = 0; i < nr_pstates; i++) {
+		u32 id = be32_to_cpu(pstate_ids[i]);
+		u32 freq = be32_to_cpu(pstate_freqs[i]);
+
+		pr_debug("PState id %d freq %d MHz\n", id, freq);
+		powernv_freqs[i].frequency = freq * 1000; /* kHz */
+		powernv_pstate_ids[i] = id;
+	}
+	/* End of list marker entry */
+	powernv_freqs[i].frequency = CPUFREQ_TABLE_END;
+
+	powernv_pstate_info.min = pstate_min;
+	powernv_pstate_info.max = pstate_max;
+	powernv_pstate_info.nominal = pstate_nominal;
+	powernv_pstate_info.nr_pstates = nr_pstates;
+
+	return 0;
+}
+
+/* Returns the CPU frequency corresponding to the pstate_id. */
+static unsigned int pstate_id_to_freq(int pstate_id)
+{
+	int i;
+
+	i = powernv_pstate_info.max - pstate_id;
+	BUG_ON(i >= powernv_pstate_info.nr_pstates || i < 0);
+
+	return powernv_freqs[i].frequency;
+}
+
+/*
+ * cpuinfo_nominal_freq_show - Show the nominal CPU frequency as indicated by
+ * the firmware
+ */
+static ssize_t cpuinfo_nominal_freq_show(struct cpufreq_policy *policy,
+					char *buf)
+{
+	return sprintf(buf, "%u\n",
+		pstate_id_to_freq(powernv_pstate_info.nominal));
+}
+
+struct freq_attr cpufreq_freq_attr_cpuinfo_nominal_freq =
+	__ATTR_RO(cpuinfo_nominal_freq);
+
+static struct freq_attr *powernv_cpu_freq_attr[] = {
+	&cpufreq_freq_attr_scaling_available_freqs,
+	&cpufreq_freq_attr_cpuinfo_nominal_freq,
+	NULL,
+};
+
+/* Helper routines */
+
+/* Access helpers to power mgt SPR */
+
+static inline unsigned long get_pmspr(unsigned long sprn)
+{
+	switch (sprn) {
+	case SPRN_PMCR:
+		return mfspr(SPRN_PMCR);
+
+	case SPRN_PMICR:
+		return mfspr(SPRN_PMICR);
+
+	case SPRN_PMSR:
+		return mfspr(SPRN_PMSR);
+	}
+	BUG();
+}
+
+static inline void set_pmspr(unsigned long sprn, unsigned long val)
+{
+	switch (sprn) {
+	case SPRN_PMCR:
+		mtspr(SPRN_PMCR, val);
+		return;
+
+	case SPRN_PMICR:
+		mtspr(SPRN_PMICR, val);
+		return;
+	}
+	BUG();
+}
+
+/*
+ * Use objects of this type to query/update
+ * pstates on a remote CPU via smp_call_function.
+ */
+struct powernv_smp_call_data {
+	unsigned int freq;
+	int pstate_id;
+};
+
+/*
+ * powernv_read_cpu_freq: Reads the current frequency on this CPU.
+ *
+ * Called via smp_call_function.
+ *
+ * Note: The caller of the smp_call_function should pass an argument of
+ * the type 'struct powernv_smp_call_data *' along with this function.
+ *
+ * The current frequency on this CPU will be returned via
+ * ((struct powernv_smp_call_data *)arg)->freq;
+ */
+static void powernv_read_cpu_freq(void *arg)
+{
+	unsigned long pmspr_val;
+	s8 local_pstate_id;
+	struct powernv_smp_call_data *freq_data = arg;
+
+	pmspr_val = get_pmspr(SPRN_PMSR);
+
+	/*
+	 * The local pstate id corresponds bits 48..55 in the PMSR.
+	 * Note: Watch out for the sign!
+	 */
+	local_pstate_id = (pmspr_val >> 48) & 0xFF;
+	freq_data->pstate_id = local_pstate_id;
+	freq_data->freq = pstate_id_to_freq(freq_data->pstate_id);
+
+	pr_debug("cpu %d pmsr %016lX pstate_id %d frequency %d kHz\n",
+		raw_smp_processor_id(), pmspr_val, freq_data->pstate_id,
+		freq_data->freq);
+}
+
+/*
+ * powernv_cpufreq_get: Returns the CPU frequency as reported by the
+ * firmware for CPU 'cpu'. This value is reported through the sysfs
+ * file cpuinfo_cur_freq.
+ */
+unsigned int powernv_cpufreq_get(unsigned int cpu)
+{
+	struct powernv_smp_call_data freq_data;
+
+	smp_call_function_any(cpu_sibling_mask(cpu), powernv_read_cpu_freq,
+			&freq_data, 1);
+
+	return freq_data.freq;
+}
+
+/*
+ * set_pstate: Sets the pstate on this CPU.
+ *
+ * This is called via an smp_call_function.
+ *
+ * The caller must ensure that freq_data is of the type
+ * (struct powernv_smp_call_data *) and the pstate_id which needs to be set
+ * on this CPU should be present in freq_data->pstate_id.
+ */
+static void set_pstate(void *freq_data)
+{
+	unsigned long val;
+	unsigned long pstate_ul =
+		((struct powernv_smp_call_data *) freq_data)->pstate_id;
+
+	val = get_pmspr(SPRN_PMCR);
+	val = val & 0x0000FFFFFFFFFFFFULL;
+
+	pstate_ul = pstate_ul & 0xFF;
+
+	/* Set both global(bits 56..63) and local(bits 48..55) PStates */
+	val = val | (pstate_ul << 56) | (pstate_ul << 48);
+
+	pr_debug("Setting cpu %d pmcr to %016lX\n",
+			raw_smp_processor_id(), val);
+	set_pmspr(SPRN_PMCR, val);
+}
+
+/*
+ * powernv_cpufreq_target_index: Sets the frequency corresponding to
+ * the cpufreq table entry indexed by new_index on the cpus in the
+ * mask policy->cpus
+ */
+static int powernv_cpufreq_target_index(struct cpufreq_policy *policy,
+					unsigned int new_index)
+{
+	struct powernv_smp_call_data freq_data;
+
+	freq_data.pstate_id = powernv_pstate_ids[new_index];
+
+	/*
+	 * Use smp_call_function to send IPI and execute the
+	 * mtspr on target CPU.  We could do that without IPI
+	 * if current CPU is within policy->cpus (core)
+	 */
+	smp_call_function_any(policy->cpus, set_pstate, &freq_data, 1);
+
+	return 0;
+}
+
+static int powernv_cpufreq_cpu_init(struct cpufreq_policy *policy)
+{
+	int base, i;
+
+	base = cpu_first_thread_sibling(policy->cpu);
+
+	for (i = 0; i < threads_per_core; i++)
+		cpumask_set_cpu(base + i, policy->cpus);
+
+	return cpufreq_table_validate_and_show(policy, powernv_freqs);
+}
+
+static struct cpufreq_driver powernv_cpufreq_driver = {
+	.name		= "powernv-cpufreq",
+	.flags		= CPUFREQ_CONST_LOOPS,
+	.init		= powernv_cpufreq_cpu_init,
+	.verify		= cpufreq_generic_frequency_table_verify,
+	.target_index	= powernv_cpufreq_target_index,
+	.get		= powernv_cpufreq_get,
+	.attr		= powernv_cpu_freq_attr,
+};
+
+static int __init powernv_cpufreq_init(void)
+{
+	int rc = 0;
+
+	/* Discover pstates from device tree and init */
+	rc = init_powernv_pstates();
+	if (rc) {
+		pr_info("powernv-cpufreq disabled. System does not support PState control\n");
+		return rc;
+	}
+
+	return cpufreq_register_driver(&powernv_cpufreq_driver);
+}
+module_init(powernv_cpufreq_init);
+
+static void __exit powernv_cpufreq_exit(void)
+{
+	cpufreq_unregister_driver(&powernv_cpufreq_driver);
+}
+module_exit(powernv_cpufreq_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Vaidyanathan Srinivasan <svaidy at linux.vnet.ibm.com>");
-- 
1.8.3.1

[PATCH v5 3/3] powernv, cpufreq: Use cpufreq_frequency_table.driver_data to store pstate ids

[Gautham R. Shenoy]

From: "Gautham R. Shenoy" <ego@linux.vnet.ibm.com>

The .driver_data field in the cpufreq_frequency_table was supposed to
be private to the drivers. However at some later point, it was being
used to indicate if the particular frequency in the table is the
BOOST_FREQUENCY. After patches [1] and [2], the .driver_data is once
again private to the driver. Thus we can safely use
cpufreq_frequency_table.driver_data to store pstate_ids instead of
having to maintain a separate array powernv_pstate_ids[] for this
purpose.

[1]:
  Subject: cpufreq: don't print value of .driver_data from core
  From   : Viresh Kumar <viresh.kumar@ linaro.org>
  url    : http://marc.info/?l=linux-pm&m=139601421504709&w=2

[2]:
  Subject: cpufreq: create another field .flags in cpufreq_frequency_table
  From   : Viresh Kumar <viresh.kumar@linaro.org>
  url    : http://marc.info/?l=linux-pm&m=139601416804702&w=2

Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
---
 drivers/cpufreq/powernv-cpufreq.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c
index e1e5197..9edccc6 100644
--- a/drivers/cpufreq/powernv-cpufreq.c
+++ b/drivers/cpufreq/powernv-cpufreq.c
@@ -33,7 +33,6 @@
 #define POWERNV_MAX_PSTATES	256
 
 static struct cpufreq_frequency_table powernv_freqs[POWERNV_MAX_PSTATES+1];
-static int powernv_pstate_ids[POWERNV_MAX_PSTATES+1];
 
 /*
  * Note: The set of pstates consists of contiguous integers, the
@@ -112,7 +111,7 @@ static int init_powernv_pstates(void)
 
 		pr_debug("PState id %d freq %d MHz\n", id, freq);
 		powernv_freqs[i].frequency = freq * 1000; /* kHz */
-		powernv_pstate_ids[i] = id;
+		powernv_freqs[i].driver_data = id;
 	}
 	/* End of list marker entry */
 	powernv_freqs[i].frequency = CPUFREQ_TABLE_END;
@@ -283,7 +282,7 @@ static int powernv_cpufreq_target_index(struct cpufreq_policy *policy,
 {
 	struct powernv_smp_call_data freq_data;
 
-	freq_data.pstate_id = powernv_pstate_ids[new_index];
+	freq_data.pstate_id = powernv_freqs[new_index].driver_data;
 
 	/*
 	 * Use smp_call_function to send IPI and execute the
-- 
1.8.3.1

Re: [PATCH v5 0/3] powernv, cpufreq: Dynamic Frequency Scaling support

[Viresh Kumar]

On 29 March 2014 01:41, Gautham R. Shenoy <ego@linux.vnet.ibm.com> wrote:
> From: "Gautham R. Shenoy" <ego@linux.vnet.ibm.com>
>
> Hi,
>
> This is v5 of the patchset to enable dynamic frequency scaling on IBM
> PowerNV platforms. This patchset does address all the review comments
> obtained for v4 (which can be found at [1]).
>
> Changes from v4:
>
>     * Created a separate patch to select the CPUFreq related Config
>       options for PowerNV
>
>     * Dropped the per-core locking hunks in
>       drivers/cpufreq/powernv-cpufreq.c since the CPUFreq core takes
>       care of the for us after the following commit which is present in
>       linux-next:
>
>         commit 12478cf0c55e5969f740bb38a24b1a0104ae18d8
>         Author: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
>         Date:   Mon Mar 24 13:35:44 2014 +0530
>
>         cpufreq: Make sure frequency transitions are serialized
>
>     * [PATCH v5 3/3] gets rid of the powernv_pstate_ids[] array that
>       was being used to record the pstate ids. After the following
>       patch it is safe to use cpufreq_frequency_table.driver_data
>       since it is opaque to the cpufreq core:
>
>         From: Viresh Kumar <viresh.kumar@linaro.org>
>         Date: 2014-03-28 13:53:47
>         url: http://marc.info/?l=linux-pm&m=139601416804702&w=2
>
>         cpufreq: create another field .flags in cpufreq_frequency_table
>
> The patchset is based on the commit
> 201544be8c37dffbf069bb5fc9edb5674f8c1754 of the linux-next tree.
>
> While all the patches in the patchset apply cleanly on linux-next,
> [PATCH v5 3/3] requires the Viresh's patch that was mentioned
> above. Otherwise, the frequency corresponding to pstate id -3 will be
> omited while reporting the "scaling_available_frequencies" in sysfs.
>
> [1]: http://marc.info/?l=linux-pm&m=139585297620612&w=2
>
> Gautham R. Shenoy (2):
>   powernv, cpufreq: Select CPUFreq related Kconfig options for powernv

Make this patch 3/3 (Probably Rafael can do this while applying)

>   powernv,cpufreq: Use cpufreq_frequency_table.driver_data to store
>     pstate ids
>
> Vaidyanathan Srinivasan (1):
>   powernv, cpufreq: cpufreq driver for powernv platform

Otherwise,

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>

[PATCH REPOST v5 2/3] powernv, cpufreq: cpufreq driver for powernv platform

[Gautham R. Shenoy]

From: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>

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 <preeti@linux.vnet.ibm.com>
Signed-off-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/reg.h    |   4 +
 drivers/cpufreq/Kconfig.powerpc   |   8 +
 drivers/cpufreq/Makefile          |   1 +
 drivers/cpufreq/powernv-cpufreq.c | 342 ++++++++++++++++++++++++++++++++++++++
 4 files changed, 355 insertions(+)
 create mode 100644 drivers/cpufreq/powernv-cpufreq.c

diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index 1a36b8e..2189f8f 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 */
diff --git a/drivers/cpufreq/Kconfig.powerpc b/drivers/cpufreq/Kconfig.powerpc
index ca0021a..72564b7 100644
--- a/drivers/cpufreq/Kconfig.powerpc
+++ b/drivers/cpufreq/Kconfig.powerpc
@@ -54,3 +54,11 @@ config PPC_PASEMI_CPUFREQ
 	help
 	  This adds the support for frequency switching on PA Semi
 	  PWRficient processors.
+
+config POWERNV_CPUFREQ
+       tristate "CPU frequency scaling for IBM POWERNV platform"
+       depends on PPC_POWERNV
+       default y
+       help
+	 This adds support for CPU frequency switching on IBM POWERNV
+	 platform
diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
index 7494565..0dbb963 100644
--- a/drivers/cpufreq/Makefile
+++ b/drivers/cpufreq/Makefile
@@ -86,6 +86,7 @@ obj-$(CONFIG_PPC_CORENET_CPUFREQ)   += ppc-corenet-cpufreq.o
 obj-$(CONFIG_CPU_FREQ_PMAC)		+= pmac32-cpufreq.o
 obj-$(CONFIG_CPU_FREQ_PMAC64)		+= pmac64-cpufreq.o
 obj-$(CONFIG_PPC_PASEMI_CPUFREQ)	+= pasemi-cpufreq.o
+obj-$(CONFIG_POWERNV_CPUFREQ)		+= powernv-cpufreq.o
 
 ##################################################################################
 # Other platform drivers
diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c
new file mode 100644
index 0000000..e1e5197
--- /dev/null
+++ b/drivers/cpufreq/powernv-cpufreq.c
@@ -0,0 +1,342 @@
+/*
+ * POWERNV cpufreq driver for the IBM POWER processors
+ *
+ * (C) Copyright IBM 2014
+ *
+ * Author: Vaidyanathan Srinivasan <svaidy at linux.vnet.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#define pr_fmt(fmt)	"powernv-cpufreq: " fmt
+
+#include <linux/kernel.h>
+#include <linux/sysfs.h>
+#include <linux/cpumask.h>
+#include <linux/module.h>
+#include <linux/cpufreq.h>
+#include <linux/smp.h>
+#include <linux/of.h>
+
+#include <asm/cputhreads.h>
+#include <asm/reg.h>
+
+#define POWERNV_MAX_PSTATES	256
+
+static struct cpufreq_frequency_table powernv_freqs[POWERNV_MAX_PSTATES+1];
+static int powernv_pstate_ids[POWERNV_MAX_PSTATES+1];
+
+/*
+ * Note: The set of pstates consists of contiguous integers, the
+ * smallest of which is indicated by powernv_pstate_info.min, the
+ * largest of which is indicated by powernv_pstate_info.max.
+ *
+ * The nominal pstate is the highest non-turbo pstate in this
+ * platform. This is indicated by powernv_pstate_info.nominal.
+ */
+static struct powernv_pstate_info {
+	int min;
+	int max;
+	int nominal;
+	int nr_pstates;
+} powernv_pstate_info;
+
+/*
+ * Initialize the freq table based on data obtained
+ * from the firmware passed via device-tree
+ */
+static int init_powernv_pstates(void)
+{
+	struct device_node *power_mgt;
+	int i, pstate_min, pstate_max, pstate_nominal, nr_pstates = 0;
+	const __be32 *pstate_ids, *pstate_freqs;
+	u32 len_ids, len_freqs;
+
+	power_mgt = of_find_node_by_path("/ibm,opal/power-mgt");
+	if (!power_mgt) {
+		pr_warn("power-mgt node not found\n");
+		return -ENODEV;
+	}
+
+	if (of_property_read_u32(power_mgt, "ibm,pstate-min", &pstate_min)) {
+		pr_warn("ibm,pstate-min node not found\n");
+		return -ENODEV;
+	}
+
+	if (of_property_read_u32(power_mgt, "ibm,pstate-max", &pstate_max)) {
+		pr_warn("ibm,pstate-max node not found\n");
+		return -ENODEV;
+	}
+
+	if (of_property_read_u32(power_mgt, "ibm,pstate-nominal",
+				 &pstate_nominal)) {
+		pr_warn("ibm,pstate-nominal not found\n");
+		return -ENODEV;
+	}
+	pr_info("cpufreq pstate min %d nominal %d max %d\n", pstate_min,
+		pstate_nominal, pstate_max);
+
+	pstate_ids = of_get_property(power_mgt, "ibm,pstate-ids", &len_ids);
+	if (!pstate_ids) {
+		pr_warn("ibm,pstate-ids not found\n");
+		return -ENODEV;
+	}
+
+	pstate_freqs = of_get_property(power_mgt, "ibm,pstate-frequencies-mhz",
+				      &len_freqs);
+	if (!pstate_freqs) {
+		pr_warn("ibm,pstate-frequencies-mhz not found\n");
+		return -ENODEV;
+	}
+
+	WARN_ON(len_ids != len_freqs);
+	nr_pstates = min(len_ids, len_freqs) / sizeof(u32);
+	if (!nr_pstates) {
+		pr_warn("No PStates found\n");
+		return -ENODEV;
+	}
+
+	pr_debug("NR PStates %d\n", nr_pstates);
+	for (i = 0; i < nr_pstates; i++) {
+		u32 id = be32_to_cpu(pstate_ids[i]);
+		u32 freq = be32_to_cpu(pstate_freqs[i]);
+
+		pr_debug("PState id %d freq %d MHz\n", id, freq);
+		powernv_freqs[i].frequency = freq * 1000; /* kHz */
+		powernv_pstate_ids[i] = id;
+	}
+	/* End of list marker entry */
+	powernv_freqs[i].frequency = CPUFREQ_TABLE_END;
+
+	powernv_pstate_info.min = pstate_min;
+	powernv_pstate_info.max = pstate_max;
+	powernv_pstate_info.nominal = pstate_nominal;
+	powernv_pstate_info.nr_pstates = nr_pstates;
+
+	return 0;
+}
+
+/* Returns the CPU frequency corresponding to the pstate_id. */
+static unsigned int pstate_id_to_freq(int pstate_id)
+{
+	int i;
+
+	i = powernv_pstate_info.max - pstate_id;
+	BUG_ON(i >= powernv_pstate_info.nr_pstates || i < 0);
+
+	return powernv_freqs[i].frequency;
+}
+
+/*
+ * cpuinfo_nominal_freq_show - Show the nominal CPU frequency as indicated by
+ * the firmware
+ */
+static ssize_t cpuinfo_nominal_freq_show(struct cpufreq_policy *policy,
+					char *buf)
+{
+	return sprintf(buf, "%u\n",
+		pstate_id_to_freq(powernv_pstate_info.nominal));
+}
+
+struct freq_attr cpufreq_freq_attr_cpuinfo_nominal_freq =
+	__ATTR_RO(cpuinfo_nominal_freq);
+
+static struct freq_attr *powernv_cpu_freq_attr[] = {
+	&cpufreq_freq_attr_scaling_available_freqs,
+	&cpufreq_freq_attr_cpuinfo_nominal_freq,
+	NULL,
+};
+
+/* Helper routines */
+
+/* Access helpers to power mgt SPR */
+
+static inline unsigned long get_pmspr(unsigned long sprn)
+{
+	switch (sprn) {
+	case SPRN_PMCR:
+		return mfspr(SPRN_PMCR);
+
+	case SPRN_PMICR:
+		return mfspr(SPRN_PMICR);
+
+	case SPRN_PMSR:
+		return mfspr(SPRN_PMSR);
+	}
+	BUG();
+}
+
+static inline void set_pmspr(unsigned long sprn, unsigned long val)
+{
+	switch (sprn) {
+	case SPRN_PMCR:
+		mtspr(SPRN_PMCR, val);
+		return;
+
+	case SPRN_PMICR:
+		mtspr(SPRN_PMICR, val);
+		return;
+	}
+	BUG();
+}
+
+/*
+ * Use objects of this type to query/update
+ * pstates on a remote CPU via smp_call_function.
+ */
+struct powernv_smp_call_data {
+	unsigned int freq;
+	int pstate_id;
+};
+
+/*
+ * powernv_read_cpu_freq: Reads the current frequency on this CPU.
+ *
+ * Called via smp_call_function.
+ *
+ * Note: The caller of the smp_call_function should pass an argument of
+ * the type 'struct powernv_smp_call_data *' along with this function.
+ *
+ * The current frequency on this CPU will be returned via
+ * ((struct powernv_smp_call_data *)arg)->freq;
+ */
+static void powernv_read_cpu_freq(void *arg)
+{
+	unsigned long pmspr_val;
+	s8 local_pstate_id;
+	struct powernv_smp_call_data *freq_data = arg;
+
+	pmspr_val = get_pmspr(SPRN_PMSR);
+
+	/*
+	 * The local pstate id corresponds bits 48..55 in the PMSR.
+	 * Note: Watch out for the sign!
+	 */
+	local_pstate_id = (pmspr_val >> 48) & 0xFF;
+	freq_data->pstate_id = local_pstate_id;
+	freq_data->freq = pstate_id_to_freq(freq_data->pstate_id);
+
+	pr_debug("cpu %d pmsr %016lX pstate_id %d frequency %d kHz\n",
+		raw_smp_processor_id(), pmspr_val, freq_data->pstate_id,
+		freq_data->freq);
+}
+
+/*
+ * powernv_cpufreq_get: Returns the CPU frequency as reported by the
+ * firmware for CPU 'cpu'. This value is reported through the sysfs
+ * file cpuinfo_cur_freq.
+ */
+unsigned int powernv_cpufreq_get(unsigned int cpu)
+{
+	struct powernv_smp_call_data freq_data;
+
+	smp_call_function_any(cpu_sibling_mask(cpu), powernv_read_cpu_freq,
+			&freq_data, 1);
+
+	return freq_data.freq;
+}
+
+/*
+ * set_pstate: Sets the pstate on this CPU.
+ *
+ * This is called via an smp_call_function.
+ *
+ * The caller must ensure that freq_data is of the type
+ * (struct powernv_smp_call_data *) and the pstate_id which needs to be set
+ * on this CPU should be present in freq_data->pstate_id.
+ */
+static void set_pstate(void *freq_data)
+{
+	unsigned long val;
+	unsigned long pstate_ul =
+		((struct powernv_smp_call_data *) freq_data)->pstate_id;
+
+	val = get_pmspr(SPRN_PMCR);
+	val = val & 0x0000FFFFFFFFFFFFULL;
+
+	pstate_ul = pstate_ul & 0xFF;
+
+	/* Set both global(bits 56..63) and local(bits 48..55) PStates */
+	val = val | (pstate_ul << 56) | (pstate_ul << 48);
+
+	pr_debug("Setting cpu %d pmcr to %016lX\n",
+			raw_smp_processor_id(), val);
+	set_pmspr(SPRN_PMCR, val);
+}
+
+/*
+ * powernv_cpufreq_target_index: Sets the frequency corresponding to
+ * the cpufreq table entry indexed by new_index on the cpus in the
+ * mask policy->cpus
+ */
+static int powernv_cpufreq_target_index(struct cpufreq_policy *policy,
+					unsigned int new_index)
+{
+	struct powernv_smp_call_data freq_data;
+
+	freq_data.pstate_id = powernv_pstate_ids[new_index];
+
+	/*
+	 * Use smp_call_function to send IPI and execute the
+	 * mtspr on target CPU.  We could do that without IPI
+	 * if current CPU is within policy->cpus (core)
+	 */
+	smp_call_function_any(policy->cpus, set_pstate, &freq_data, 1);
+
+	return 0;
+}
+
+static int powernv_cpufreq_cpu_init(struct cpufreq_policy *policy)
+{
+	int base, i;
+
+	base = cpu_first_thread_sibling(policy->cpu);
+
+	for (i = 0; i < threads_per_core; i++)
+		cpumask_set_cpu(base + i, policy->cpus);
+
+	return cpufreq_table_validate_and_show(policy, powernv_freqs);
+}
+
+static struct cpufreq_driver powernv_cpufreq_driver = {
+	.name		= "powernv-cpufreq",
+	.flags		= CPUFREQ_CONST_LOOPS,
+	.init		= powernv_cpufreq_cpu_init,
+	.verify		= cpufreq_generic_frequency_table_verify,
+	.target_index	= powernv_cpufreq_target_index,
+	.get		= powernv_cpufreq_get,
+	.attr		= powernv_cpu_freq_attr,
+};
+
+static int __init powernv_cpufreq_init(void)
+{
+	int rc = 0;
+
+	/* Discover pstates from device tree and init */
+	rc = init_powernv_pstates();
+	if (rc) {
+		pr_info("powernv-cpufreq disabled. System does not support PState control\n");
+		return rc;
+	}
+
+	return cpufreq_register_driver(&powernv_cpufreq_driver);
+}
+module_init(powernv_cpufreq_init);
+
+static void __exit powernv_cpufreq_exit(void)
+{
+	cpufreq_unregister_driver(&powernv_cpufreq_driver);
+}
+module_exit(powernv_cpufreq_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Vaidyanathan Srinivasan <svaidy at linux.vnet.ibm.com>");
-- 
1.8.3.1

[PATCH REPOST v5 3/3] powernv, cpufreq: Use cpufreq_frequency_table.driver_data to store pstate ids

[Gautham R. Shenoy]

From: "Gautham R. Shenoy" <ego@linux.vnet.ibm.com>

The .driver_data field in the cpufreq_frequency_table was supposed to
be private to the drivers. However at some later point, it was being
used to indicate if the particular frequency in the table is the
BOOST_FREQUENCY. After patches [1] and [2], the .driver_data is once
again private to the driver. Thus we can safely use
cpufreq_frequency_table.driver_data to store pstate_ids instead of
having to maintain a separate array powernv_pstate_ids[] for this
purpose.

[1]:
  Subject: cpufreq: don't print value of .driver_data from core
  From   : Viresh Kumar <viresh.kumar@ linaro.org>
  url    : http://marc.info/?l=linux-pm&m=139601421504709&w=2

[2]:
  Subject: cpufreq: create another field .flags in cpufreq_frequency_table
  From   : Viresh Kumar <viresh.kumar@linaro.org>
  url    : http://marc.info/?l=linux-pm&m=139601416804702&w=2

Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
---
 drivers/cpufreq/powernv-cpufreq.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c
index e1e5197..9edccc6 100644
--- a/drivers/cpufreq/powernv-cpufreq.c
+++ b/drivers/cpufreq/powernv-cpufreq.c
@@ -33,7 +33,6 @@
 #define POWERNV_MAX_PSTATES	256
 
 static struct cpufreq_frequency_table powernv_freqs[POWERNV_MAX_PSTATES+1];
-static int powernv_pstate_ids[POWERNV_MAX_PSTATES+1];
 
 /*
  * Note: The set of pstates consists of contiguous integers, the
@@ -112,7 +111,7 @@ static int init_powernv_pstates(void)
 
 		pr_debug("PState id %d freq %d MHz\n", id, freq);
 		powernv_freqs[i].frequency = freq * 1000; /* kHz */
-		powernv_pstate_ids[i] = id;
+		powernv_freqs[i].driver_data = id;
 	}
 	/* End of list marker entry */
 	powernv_freqs[i].frequency = CPUFREQ_TABLE_END;
@@ -283,7 +282,7 @@ static int powernv_cpufreq_target_index(struct cpufreq_policy *policy,
 {
 	struct powernv_smp_call_data freq_data;
 
-	freq_data.pstate_id = powernv_pstate_ids[new_index];
+	freq_data.pstate_id = powernv_freqs[new_index].driver_data;
 
 	/*
 	 * Use smp_call_function to send IPI and execute the
-- 
1.8.3.1

[PATCH REPOST v5 1/3] powernv, cpufreq: Select CPUFreq related Kconfig options for powernv

[Gautham R. Shenoy]

From: "Gautham R. Shenoy" <ego@linux.vnet.ibm.com>

Enable CPUFreq for PowerNV. Select "performance", "powersave",
"userspace" and "ondemand" governors. Choose "ondemand" to be the
default governor.

Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
---
 arch/powerpc/configs/pseries_defconfig    | 1 +
 arch/powerpc/configs/pseries_le_defconfig | 1 +
 arch/powerpc/platforms/powernv/Kconfig    | 6 ++++++
 3 files changed, 8 insertions(+)

diff --git a/arch/powerpc/configs/pseries_defconfig b/arch/powerpc/configs/pseries_defconfig
index 9ea8342b..a905063 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 3c84f9d..58e3dbf 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 895e8a2..c252ee9 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
-- 
1.8.3.1

Re: [PATCH REPOST v5 1/3] powernv, cpufreq: Select CPUFreq related Kconfig options for powernv

[Benjamin Herrenschmidt]

On Tue, 2014-04-01 at 12:43 +0530, Gautham R. Shenoy wrote:
> From: "Gautham R. Shenoy" <ego@linux.vnet.ibm.com>
> 
> Enable CPUFreq for PowerNV. Select "performance", "powersave",
> "userspace" and "ondemand" governors. Choose "ondemand" to be the
> default governor.

Rafael, are you going to take these or should I send them to Linus ?

(I'd rather you take them :-)

Cheers,
Ben.

> 
> Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
> ---
>  arch/powerpc/configs/pseries_defconfig    | 1 +
>  arch/powerpc/configs/pseries_le_defconfig | 1 +
>  arch/powerpc/platforms/powernv/Kconfig    | 6 ++++++
>  3 files changed, 8 insertions(+)
> 
> diff --git a/arch/powerpc/configs/pseries_defconfig b/arch/powerpc/configs/pseries_defconfig
> index 9ea8342b..a905063 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 3c84f9d..58e3dbf 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 895e8a2..c252ee9 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

Re: [PATCH REPOST v5 1/3] powernv, cpufreq: Select CPUFreq related Kconfig options for powernv

[Rafael J. Wysocki]

On Tuesday, April 01, 2014 08:46:49 PM Benjamin Herrenschmidt wrote:
> On Tue, 2014-04-01 at 12:43 +0530, Gautham R. Shenoy wrote:
> > From: "Gautham R. Shenoy" <ego@linux.vnet.ibm.com>
> > 
> > Enable CPUFreq for PowerNV. Select "performance", "powersave",
> > "userspace" and "ondemand" governors. Choose "ondemand" to be the
> > default governor.
> 
> Rafael, are you going to take these or should I send them to Linus ?
> 
> (I'd rather you take them :-)

I can do that, but the timing is pretty bad.  How urgent are they?

Rafael

Re: [PATCH REPOST v5 1/3] powernv, cpufreq: Select CPUFreq related Kconfig options for powernv

[Benjamin Herrenschmidt]

On Wed, 2014-04-02 at 00:03 +0200, Rafael J. Wysocki wrote:
> > Rafael, are you going to take these or should I send them to Linus ?
> > 
> > (I'd rather you take them :-)
> 
> I can do that, but the timing is pretty bad.  How urgent are they?

To be honest pretty urgent. It's a new drop-in driver so it shouldn't
be a huge deal.

We have distros really waiting for this to hit upstream... But I'll
leave that decision to you :-)

Cheers,
Ben.

Re: [PATCH REPOST v5 1/3] powernv, cpufreq: Select CPUFreq related Kconfig options for powernv

[Rafael J. Wysocki]

On Wednesday, April 02, 2014 03:23:28 PM Benjamin Herrenschmidt wrote:
> On Wed, 2014-04-02 at 00:03 +0200, Rafael J. Wysocki wrote:
> > > Rafael, are you going to take these or should I send them to Linus ?
> > > 
> > > (I'd rather you take them :-)
> > 
> > I can do that, but the timing is pretty bad.  How urgent are they?
> 
> To be honest pretty urgent. It's a new drop-in driver so it shouldn't
> be a huge deal.
> 
> We have distros really waiting for this to hit upstream... But I'll
> leave that decision to you :-)

Well, I've already sent a second pull request for this merge window
and I'm not going to send the next one before it is merged.

So, I can push them next week realistically.

Rafael

Re: [PATCH REPOST v5 1/3] powernv, cpufreq: Select CPUFreq related Kconfig options for powernv

[Benjamin Herrenschmidt]

On Wed, 2014-04-02 at 13:03 +0200, Rafael J. Wysocki wrote:
> > To be honest pretty urgent. It's a new drop-in driver so it
> shouldn't
> > be a huge deal.
> > 
> > We have distros really waiting for this to hit upstream... But I'll
> > leave that decision to you :-)
> 
> Well, I've already sent a second pull request for this merge window
> and I'm not going to send the next one before it is merged.
> 
> So, I can push them next week realistically.

Thanks. You can blame me for the lateness if you want (and the debate as
to which tree should carry them :-)

Cheers,
Ben.