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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, Nov 4, 2014 at 6:13 PM, Stefano Stabellini
<stefano.stabellini@xxxxxxxxxxxxx> wrote:
> 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?
I'll create an event channel between Xen and hwdom.
In this case global VIRQ_CPUFREQ will not be needed and Xen and hwdom
will be able to send notification to each other,
>> + 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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