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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [RFC PATCH v4 10/11] cpufreq: add hwdom-cpufreq driver
On Tue, 4 Nov 2014, Oleksandr Dmytryshyn wrote:
> This driver uses hwdom to change frequencies on CPUs
> Workflow:
> * cpufreq governor driver in Xen wants to change the
> frequency of the physical CPU
> * hwdom-cpufreq driver sets parameters in the shared
> memory
> * hwdom-cpufreq driver sends an VIRQ_CPUFREQ interrupt
> to notify the hardware domain
> * cpufreq driver in the hardware domain reads parameters
> from the shared memory, changes frequency and copies
> the result of the operation to the shared memory
>
> Signed-off-by: Oleksandr Dmytryshyn <oleksandr.dmytryshyn@xxxxxxxxxxxxxxx>
> ---
> xen/Rules.mk | 1 +
> xen/drivers/cpufreq/Makefile | 1 +
> xen/drivers/cpufreq/hwdom-cpufreq.c | 252
> ++++++++++++++++++++++++++++++++++++
> xen/include/public/xen.h | 1 +
> 4 files changed, 255 insertions(+)
> create mode 100644 xen/drivers/cpufreq/hwdom-cpufreq.c
>
> diff --git a/xen/Rules.mk b/xen/Rules.mk
> index 3b0b89b..cccbc72 100644
> --- a/xen/Rules.mk
> +++ b/xen/Rules.mk
> @@ -56,6 +56,7 @@ CFLAGS-$(perfc_arrays) += -DPERF_ARRAYS
> CFLAGS-$(lock_profile) += -DLOCK_PROFILE
> CFLAGS-$(HAS_ACPI) += -DHAS_ACPI
> CFLAGS-$(HAS_CPUFREQ) += -DHAS_CPUFREQ
> +CFLAGS-$(HAS_HWDOM_CPUFREQ) += -DHAS_HWDOM_CPUFREQ
> CFLAGS-$(HAS_PM) += -DHAS_PM
> CFLAGS-$(HAS_CPU_TURBO) += -DHAS_CPU_TURBO
> CFLAGS-$(HAS_GDBSX) += -DHAS_GDBSX
> diff --git a/xen/drivers/cpufreq/Makefile b/xen/drivers/cpufreq/Makefile
> index b87d127..891997c 100644
> --- a/xen/drivers/cpufreq/Makefile
> +++ b/xen/drivers/cpufreq/Makefile
> @@ -2,3 +2,4 @@ obj-y += cpufreq.o
> obj-y += cpufreq_ondemand.o
> obj-y += cpufreq_misc_governors.o
> obj-y += utility.o
> +obj-$(HAS_HWDOM_CPUFREQ) += hwdom-cpufreq.o
> diff --git a/xen/drivers/cpufreq/hwdom-cpufreq.c
> b/xen/drivers/cpufreq/hwdom-cpufreq.c
> new file mode 100644
> index 0000000..a39fc6c
> --- /dev/null
> +++ b/xen/drivers/cpufreq/hwdom-cpufreq.c
> @@ -0,0 +1,252 @@
> +/*
> + * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@xxxxxxxxx>
> + * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@xxxxxxxxx>
> + * Copyright (C) 2002 - 2004 Dominik Brodowski <linux@xxxxxxxx>
> + * Copyright (C) 2006 Denis Sadykov <denis.m.sadykov@xxxxxxxxx>
> + *
> + * Feb 2008 - Liu Jinsong <jinsong.liu@xxxxxxxxx>
> + * porting acpi-cpufreq.c from Linux 2.6.23 to Xen hypervisor
> + *
> + * Copyright (C) 2014 GlobalLogic Inc.
> + *
> + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> + *
> + * 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 of the License, 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.
> + *
> + * You should have received a copy of the GNU General Public License along
> + * with this program; if not, write to the Free Software Foundation, Inc.,
> + * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
> + *
> + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> + */
> +#include <xen/types.h>
> +#include <xen/errno.h>
> +#include <xen/sched.h>
> +#include <xen/event.h>
> +#include <xen/irq.h>
> +#include <xen/spinlock.h>
> +#include <xen/cpufreq.h>
> +#include <xen/err.h>
> +#include <asm/shared.h>
> +#include <asm/current.h>
> +#include <asm/system.h>
> +
> +struct hwdom_cpufreq_data {
> + struct processor_performance *perf_data;
> + struct cpufreq_frequency_table *freq_table;
> +};
> +
> +static struct hwdom_cpufreq_data *hwdom_cpufreq_drv_data[NR_CPUS];
> +
> +int cpufreq_cpu_init(unsigned int cpuid)
> +{
> + return cpufreq_add_cpu(cpuid);
> +}
> +
> +static void notify_cpufreq_domain(void)
> +{
> + send_global_virq(VIRQ_CPUFREQ);
> +}
> +
> +static int hwdom_cpufreq_verify(struct cpufreq_policy *policy)
> +{
> + struct hwdom_cpufreq_data *data;
> + struct processor_performance *perf;
> +
> + if ( !policy || !(data = hwdom_cpufreq_drv_data[policy->cpu]) ||
> + !processor_pminfo[policy->cpu] )
> + return -EINVAL;
> +
> + perf = &processor_pminfo[policy->cpu]->perf;
> +
> + cpufreq_verify_within_limits(policy, 0,
> + perf->states[perf->platform_limit].core_frequency * 1000);
> +
> + return cpufreq_frequency_table_verify(policy, data->freq_table);
> +}
> +
> +static int hwdom_cpufreq_target(struct cpufreq_policy *policy,
> + unsigned int target_freq, unsigned int
> relation)
> +{
> + struct hwdom_cpufreq_data *data = hwdom_cpufreq_drv_data[policy->cpu];
> + struct processor_performance *perf;
> + struct cpufreq_freqs freqs;
> + struct cpufreq_sh_info *cpufreq_info;
> + cpumask_t online_policy_cpus;
> + unsigned int next_state = 0; /* Index into freq_table */
> + unsigned int next_perf_state = 0; /* Index into perf table */
> + unsigned int j;
> + int ret = 0;
> +
> + if ( unlikely(data == NULL ||
> + data->perf_data == NULL || data->freq_table == NULL) )
> + return -ENODEV;
> +
> + perf = data->perf_data;
> + ret = cpufreq_frequency_table_target(policy,
> + data->freq_table,
> + target_freq,
> + relation, &next_state);
> + if ( unlikely(ret) )
> + return -ENODEV;
> +
> + cpumask_and(&online_policy_cpus, &cpu_online_map, policy->cpus);
> +
> + next_perf_state = data->freq_table[next_state].index;
> + if ( perf->state == next_perf_state )
> + {
> + if ( unlikely(policy->resume) )
> + policy->resume = 0;
> + else
> + return 0;
> + }
> +
> + freqs.old = perf->states[perf->state].core_frequency * 1000;
> + freqs.new = data->freq_table[next_state].frequency;
> +
> + /* Do send cmd for Hardware domain */
> + cpufreq_info = arch_get_cpufreq_addr(dom0);
> +
> + /* Set previous result in the Hardware domain then read it */
> + smp_rmb();
> +
> + /* return previous result */
> + ret = cpufreq_info->result;
What if the previous command hasn't completed yet?
> + cpufreq_info->cpu = policy->cpu;
> + cpufreq_info->freq = freqs.new;
> + cpufreq_info->relation = (uint32_t)relation;
> +
> + smp_wmb(); /* above must be visible before notify_cpufreq_domain() */
> +
> + notify_cpufreq_domain();
> +
> + for_each_cpu( j, &online_policy_cpus )
> + cpufreq_statistic_update(j, perf->state, next_perf_state);
> +
> + perf->state = next_perf_state;
> + policy->cur = freqs.new;
> +
> + return ret;
> +}
> +
> +static int
> +hwdom_cpufreq_cpu_init(struct cpufreq_policy *policy)
> +{
> + struct processor_performance *perf;
> + struct hwdom_cpufreq_data *data;
> + unsigned int cpu = policy->cpu;
> + unsigned int valid_states = 0;
> + int i;
> + int ret = 0;
> +
> + data = xzalloc(struct hwdom_cpufreq_data);
> + if ( !data )
> + return -ENOMEM;
> +
> + hwdom_cpufreq_drv_data[cpu] = data;
> +
> + data->perf_data = &processor_pminfo[cpu]->perf;
> +
> + perf = data->perf_data;
> + policy->shared_type = perf->shared_type;
> +
> + data->freq_table = xmalloc_array(struct cpufreq_frequency_table,
> + (perf->state_count+1));
> + if ( !data->freq_table )
> + {
> + ret = -ENOMEM;
> + goto err_unreg;
> + }
> +
> + /* detect transition latency */
> + policy->cpuinfo.transition_latency = 0;
> + for ( i = 0; i < perf->state_count; i++ )
> + {
> + if ( (perf->states[i].transition_latency * 1000) >
> + policy->cpuinfo.transition_latency )
> + policy->cpuinfo.transition_latency =
> + perf->states[i].transition_latency * 1000;
> + }
> +
> + policy->governor = cpufreq_opt_governor ? : CPUFREQ_DEFAULT_GOVERNOR;
> +
> + /* table init */
> + for ( i = 0; i < perf->state_count; i++ )
> + {
> + if ( i > 0 && perf->states[i].core_frequency >=
> + data->freq_table[valid_states-1].frequency / 1000 )
> + continue;
> +
> + data->freq_table[valid_states].index = i;
> + data->freq_table[valid_states].frequency =
> + perf->states[i].core_frequency * 1000;
> + valid_states++;
> + }
> + data->freq_table[valid_states].frequency = CPUFREQ_TABLE_END;
> + perf->state = 0;
> +
> + ret = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
> + if ( ret )
> + goto err_freqfree;
> +
> +
> + /*
> + * the first call to ->target() should result in us actually
> + * send command to the Hardware domain to set frequency.
> + */
> + policy->resume = 1;
> +
> + /* Set the minimal frequency */
> + return hwdom_cpufreq_target(policy, policy->min, CPUFREQ_RELATION_L);
> +
> + err_freqfree:
> + xfree(data->freq_table);
> + err_unreg:
> + xfree(data);
> + hwdom_cpufreq_drv_data[cpu] = NULL;
> +
> + return ret;
> +}
> +
> +static int hwdom_cpufreq_cpu_exit(struct cpufreq_policy *policy)
> +{
> + struct hwdom_cpufreq_data *data = hwdom_cpufreq_drv_data[policy->cpu];
> +
> + if ( data )
> + {
> + hwdom_cpufreq_drv_data[policy->cpu] = NULL;
> + xfree(data->freq_table);
> + xfree(data);
> + }
> +
> + return 0;
> +}
> +
> +static struct cpufreq_driver hwdom_cpufreq_driver = {
> + .name = "hwdom-cpufreq",
> + .verify = hwdom_cpufreq_verify,
> + .target = hwdom_cpufreq_target,
> + .init = hwdom_cpufreq_cpu_init,
> + .exit = hwdom_cpufreq_cpu_exit,
> +};
> +
> +static int __init hwdom_cpufreq_driver_init(void)
> +{
> + int ret = 0;
> +
> + if ( cpufreq_controller == FREQCTL_xen )
> + ret = cpufreq_register_driver(&hwdom_cpufreq_driver);
> +
> + return ret;
> +}
> +
> +__initcall(hwdom_cpufreq_driver_init);
> diff --git a/xen/include/public/xen.h b/xen/include/public/xen.h
> index 8c5697e..abd8438 100644
> --- a/xen/include/public/xen.h
> +++ b/xen/include/public/xen.h
> @@ -160,6 +160,7 @@ DEFINE_XEN_GUEST_HANDLE(xen_ulong_t);
> #define VIRQ_MEM_EVENT 10 /* G. (DOM0) A memory event has occured
> */
> #define VIRQ_XC_RESERVED 11 /* G. Reserved for XenClient
> */
> #define VIRQ_ENOMEM 12 /* G. (DOM0) Low on heap memory */
> +#define VIRQ_CPUFREQ 14 /* G. (DOM0) Notify cpufreq driver
> */
>
> /* Architecture-specific VIRQ definitions. */
> #define VIRQ_ARCH_0 16
> --
> 1.9.1
>
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