[PATCH 2.5.57] cpufreq: per-CPU initialization

Dominik Brodowski (linux@brodo.de)
Mon, 13 Jan 2003 21:54:46 +0100


(depends on the "cpufreq: add sysfs interface" patch)

Allow for per-CPU initialization of CPUfreq. Therefore, it's not
necessary any longer to kmalloc the per-CPU policy struct. To use
this, cpufreq_driver->policy has to be set to NULL. Of course,
cpufreq_driver->init is needed then, which is the appropriate function
for CPU initialization. cpufreq_driver->exit is available for cleanup.

All existing drivers continue to work without any changes, just for
clarity ->init and ->exit are set to NULL, and the names accordingly.

Dominik

diff -ruN linux-original/arch/arm/mach-integrator/cpu.c linux/arch/arm/mach-integrator/cpu.c
--- linux-original/arch/arm/mach-integrator/cpu.c 2003-01-13 21:08:03.000000000 +0100
+++ linux/arch/arm/mach-integrator/cpu.c 2003-01-13 21:45:03.000000000 +0100
@@ -166,6 +166,7 @@
.verify = integrator_verify_speed,
.setpolicy = integrator_set_policy,
.policy = &integrator_policy,
+ .name = "integrator\0",
};
#endif

diff -ruN linux-original/arch/arm/mach-sa1100/cpu-sa1100.c linux/arch/arm/mach-sa1100/cpu-sa1100.c
--- linux-original/arch/arm/mach-sa1100/cpu-sa1100.c 2003-01-13 21:08:03.000000000 +0100
+++ linux/arch/arm/mach-sa1100/cpu-sa1100.c 2003-01-13 21:45:03.000000000 +0100
@@ -214,6 +214,7 @@
.verify = sa11x0_verify_speed,
.setpolicy = sa1100_setspeed,
.policy = &sa1100_policy,
+ .name = "sa1100\0",
};

static int __init sa1100_dram_init(void)
diff -ruN linux-original/arch/arm/mach-sa1100/cpu-sa1110.c linux/arch/arm/mach-sa1100/cpu-sa1110.c
--- linux-original/arch/arm/mach-sa1100/cpu-sa1110.c 2003-01-13 21:08:03.000000000 +0100
+++ linux/arch/arm/mach-sa1100/cpu-sa1110.c 2003-01-13 21:45:03.000000000 +0100
@@ -309,6 +309,7 @@
.verify = sa11x0_verify_speed,
.setpolicy = sa1110_setspeed,
.policy = &sa1110_policy,
+ .name = "sa1110\0",
};

static int __init sa1110_clk_init(void)
diff -ruN linux-original/arch/i386/kernel/cpu/cpufreq/elanfreq.c linux/arch/i386/kernel/cpu/cpufreq/elanfreq.c
--- linux-original/arch/i386/kernel/cpu/cpufreq/elanfreq.c 2003-01-13 21:08:03.000000000 +0100
+++ linux/arch/i386/kernel/cpu/cpufreq/elanfreq.c 2003-01-13 21:45:03.000000000 +0100
@@ -260,6 +260,9 @@

driver->verify = &elanfreq_verify;
driver->setpolicy = &elanfreq_setpolicy;
+ driver->init = NULL;
+ driver->exit = NULL;
+ strncpy(driver->name, "elanfrep\0", CPUFREQ_NAME_LEN);

driver->policy[0].cpu = 0;
ret = cpufreq_frequency_table_cpuinfo(&driver->policy[0], &elanfreq_table[0]);
diff -ruN linux-original/arch/i386/kernel/cpu/cpufreq/gx-suspmod.c linux/arch/i386/kernel/cpu/cpufreq/gx-suspmod.c
--- linux-original/arch/i386/kernel/cpu/cpufreq/gx-suspmod.c 2003-01-13 21:15:55.000000000 +0100
+++ linux/arch/i386/kernel/cpu/cpufreq/gx-suspmod.c 2003-01-13 21:45:03.000000000 +0100
@@ -482,6 +482,9 @@
driver->policy[0].cpuinfo.transition_latency = CPUFREQ_ETERNAL;
driver->verify = &cpufreq_gx_verify;
driver->setpolicy = &cpufreq_gx_setpolicy;
+ driver->init = NULL;
+ driver->exit = NULL;
+ strncpy(driver->name, "gx-suspmod\0", CPUFREQ_NAME_LEN);

gx_driver = driver;

diff -ruN linux-original/arch/i386/kernel/cpu/cpufreq/longhaul.c linux/arch/i386/kernel/cpu/cpufreq/longhaul.c
--- linux-original/arch/i386/kernel/cpu/cpufreq/longhaul.c 2003-01-13 21:08:03.000000000 +0100
+++ linux/arch/i386/kernel/cpu/cpufreq/longhaul.c 2003-01-13 21:45:03.000000000 +0100
@@ -771,6 +771,9 @@

driver->verify = &longhaul_verify;
driver->setpolicy = &longhaul_setpolicy;
+ driver->init = NULL;
+ driver->exit = NULL;
+ strncpy(driver->name, "longhaul\0", CPUFREQ_NAME_LEN);

driver->policy[0].cpu = 0;
driver->policy[0].min = (unsigned int) lowest_speed;
diff -ruN linux-original/arch/i386/kernel/cpu/cpufreq/longrun.c linux/arch/i386/kernel/cpu/cpufreq/longrun.c
--- linux-original/arch/i386/kernel/cpu/cpufreq/longrun.c 2003-01-13 21:08:03.000000000 +0100
+++ linux/arch/i386/kernel/cpu/cpufreq/longrun.c 2003-01-13 21:45:03.000000000 +0100
@@ -251,6 +251,9 @@
driver->policy[0].cpuinfo.min_freq = longrun_low_freq;
driver->policy[0].cpuinfo.max_freq = longrun_high_freq;
driver->policy[0].cpuinfo.transition_latency = CPUFREQ_ETERNAL;
+ driver->init = NULL;
+ driver->exit = NULL;
+ strncpy(driver->name, "longrun\0", CPUFREQ_NAME_LEN);

longrun_get_policy(&driver->policy[0]);

diff -ruN linux-original/arch/i386/kernel/cpu/cpufreq/p4-clockmod.c linux/arch/i386/kernel/cpu/cpufreq/p4-clockmod.c
--- linux-original/arch/i386/kernel/cpu/cpufreq/p4-clockmod.c 2003-01-13 21:08:03.000000000 +0100
+++ linux/arch/i386/kernel/cpu/cpufreq/p4-clockmod.c 2003-01-13 21:45:03.000000000 +0100
@@ -240,6 +240,9 @@

driver->verify = &cpufreq_p4_verify;
driver->setpolicy = &cpufreq_p4_setpolicy;
+ driver->init = NULL;
+ driver->exit = NULL;
+ strncpy(driver->name, "p4-clockmod\0", CPUFREQ_NAME_LEN);

for (i=0;i<NR_CPUS;i++) {
driver->policy[i].cpu = i;
diff -ruN linux-original/arch/i386/kernel/cpu/cpufreq/powernow-k6.c linux/arch/i386/kernel/cpu/cpufreq/powernow-k6.c
--- linux-original/arch/i386/kernel/cpu/cpufreq/powernow-k6.c 2003-01-13 21:08:03.000000000 +0100
+++ linux/arch/i386/kernel/cpu/cpufreq/powernow-k6.c 2003-01-13 21:45:03.000000000 +0100
@@ -184,6 +184,9 @@

driver->verify = &powernow_k6_verify;
driver->setpolicy = &powernow_k6_setpolicy;
+ driver->init = NULL;
+ driver->exit = NULL;
+ strncpy(driver->name, "powernow-k6\0", CPUFREQ_NAME_LEN);

/* cpuinfo and default policy values */
driver->policy[0].cpu = 0;
diff -ruN linux-original/arch/i386/kernel/cpu/cpufreq/speedstep.c linux/arch/i386/kernel/cpu/cpufreq/speedstep.c
--- linux-original/arch/i386/kernel/cpu/cpufreq/speedstep.c 2003-01-13 21:08:03.000000000 +0100
+++ linux/arch/i386/kernel/cpu/cpufreq/speedstep.c 2003-01-13 21:45:03.000000000 +0100
@@ -690,6 +690,9 @@

driver->verify = &speedstep_verify;
driver->setpolicy = &speedstep_setpolicy;
+ driver->init = NULL;
+ driver->exit = NULL;
+ strncpy(driver->name, "speedstep\0", CPUFREQ_NAME_LEN);

driver->policy[0].cpuinfo.transition_latency = CPUFREQ_ETERNAL;

diff -ruN linux-original/drivers/acpi/processor.c linux/drivers/acpi/processor.c
--- linux-original/drivers/acpi/processor.c 2003-01-13 21:08:11.000000000 +0100
+++ linux/drivers/acpi/processor.c 2003-01-13 21:45:03.000000000 +0100
@@ -1823,6 +1823,9 @@

driver->verify = &acpi_cpufreq_verify;
driver->setpolicy = &acpi_cpufreq_setpolicy;
+ driver->init = NULL;
+ driver->exit = NULL;
+ strncpy(driver->name, "acpi-processor\0", CPUFREQ_NAME_LEN);

for (i=0;i<NR_CPUS;i++) {
driver->policy[i].cpu = pr->id;
diff -ruN linux-original/include/linux/cpufreq.h linux/include/linux/cpufreq.h
--- linux-original/include/linux/cpufreq.h 2003-01-13 21:37:56.000000000 +0100
+++ linux/include/linux/cpufreq.h 2003-01-13 21:45:03.000000000 +0100
@@ -109,19 +109,29 @@
* CPUFREQ DRIVER INTERFACE *
*********************************************************************/

+#define CPUFREQ_NAME_LEN 16
+
struct cpufreq_driver {
/* needed by all drivers */
int (*verify) (struct cpufreq_policy *policy);
int (*setpolicy) (struct cpufreq_policy *policy);
struct cpufreq_policy *policy;
+ char name[CPUFREQ_NAME_LEN];
+ /* optional, for the moment */
+ int (*init) (struct cpufreq_policy *policy);
+ int (*exit) (struct cpufreq_policy *policy);
/* 2.4. compatible API */
#ifdef CONFIG_CPU_FREQ_24_API
unsigned int cpu_cur_freq[NR_CPUS];
#endif
};

-int cpufreq_register(struct cpufreq_driver *driver_data);
-int cpufreq_unregister(void);
+int cpufreq_register_driver(struct cpufreq_driver *driver_data);
+int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
+/* deprecated */
+#define cpufreq_register(x) cpufreq_register_driver(x)
+#define cpufreq_unregister(x) cpufreq_unregister_driver(NULL)
+

void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state);

diff -ruN linux-original/kernel/cpufreq.c linux/kernel/cpufreq.c
--- linux-original/kernel/cpufreq.c 2003-01-13 21:37:56.000000000 +0100
+++ linux/kernel/cpufreq.c 2003-01-13 21:45:03.000000000 +0100
@@ -57,18 +57,6 @@
static DECLARE_MUTEX (cpufreq_notifier_sem);


-/**
- * The cpufreq default policy. Can be set by a "cpufreq=..." command
- * line option.
- */
-static struct cpufreq_policy default_policy = {
- .cpu = CPUFREQ_ALL_CPUS,
- .min = 0,
- .max = 0,
- .policy = 0,
-};
-
-
#ifdef CONFIG_CPU_FREQ_24_API
/**
* A few values needed by the 2.4.-compatible API
@@ -234,6 +222,25 @@


/**
+ * show_scaling_governor - show the current policy for the specified CPU
+ */
+static ssize_t show_scaling_driver (struct device *dev, char *buf)
+{
+ char value[CPUFREQ_NAME_LEN];
+
+ if (!dev)
+ return 0;
+
+ down(&cpufreq_driver_sem);
+ if (cpufreq_driver)
+ strncpy(value, cpufreq_driver->name, CPUFREQ_NAME_LEN);
+ up(&cpufreq_driver_sem);
+
+ return sprintf(buf, "%s\n", value);
+}
+
+
+/**
* cpufreq_per_cpu_attr_ro - read-only cpufreq per-CPU file
*/
#define cpufreq_per_cpu_attr_ro(file_name, object) \
@@ -257,6 +264,7 @@
cpufreq_per_cpu_attr_rw(scaling_max_freq, max);

static DEVICE_ATTR(scaling_governor, (S_IRUGO | S_IWUSR), show_scaling_governor, store_scaling_governor);
+static DEVICE_ATTR(scaling_driver, S_IRUGO, show_scaling_driver, NULL);


/**
@@ -268,6 +276,7 @@
{
unsigned int cpu = to_cpu_nr(dev);
int ret = 0;
+ struct cpufreq_policy policy;

down(&cpufreq_driver_sem);
if (!cpufreq_driver) {
@@ -275,6 +284,37 @@
return -EINVAL;
}

+ /* call driver. From then on the cpufreq must be able
+ * to accept all calls to ->verify and ->setpolicy for this CPU
+ */
+ cpufreq_driver->policy[cpu].cpu = cpu;
+ if (cpufreq_driver->init) {
+ ret = cpufreq_driver->init(&cpufreq_driver->policy[cpu]);
+ if (ret) {
+ up(&cpufreq_driver_sem);
+ return -ENODEV;
+ }
+ }
+
+ /* set default policy on this CPU */
+ policy.policy = cpufreq_driver->policy[cpu].policy;
+ policy.min = cpufreq_driver->policy[cpu].min;
+ policy.max = cpufreq_driver->policy[cpu].max;
+ policy.cpu = cpu;
+
+ up(&cpufreq_driver_sem);
+ ret = cpufreq_set_policy(&policy);
+ if (ret)
+ return -EINVAL;
+ down(&cpufreq_driver_sem);
+
+ /* 2.4-API init for this CPU */
+#ifdef CONFIG_CPU_FREQ_24_API
+ cpu_min_freq[cpu] = cpufreq_driver->policy[cpu].cpuinfo.min_freq;
+ cpu_max_freq[cpu] = cpufreq_driver->policy[cpu].cpuinfo.max_freq;
+ cpu_cur_freq[cpu] = cpufreq_driver->cpu_cur_freq[cpu];
+#endif
+
/* prepare interface data */
cpufreq_driver->policy[cpu].intf.dev = dev;
cpufreq_driver->policy[cpu].intf.intf = &cpufreq_interface;
@@ -296,6 +336,7 @@
device_create_file (dev, &dev_attr_scaling_min_freq);
device_create_file (dev, &dev_attr_scaling_max_freq);
device_create_file (dev, &dev_attr_scaling_governor);
+ device_create_file (dev, &dev_attr_scaling_driver);

up(&cpufreq_driver_sem);
return ret;
@@ -311,12 +352,17 @@
static int cpufreq_remove_dev (struct intf_data *intf)
{
struct device * dev = intf->dev;
+ unsigned int cpu = to_cpu_nr(dev);
+
+ if (cpufreq_driver->exit)
+ cpufreq_driver->exit(&cpufreq_driver->policy[cpu]);

device_remove_file (dev, &dev_attr_cpuinfo_min_freq);
device_remove_file (dev, &dev_attr_cpuinfo_max_freq);
device_remove_file (dev, &dev_attr_scaling_min_freq);
device_remove_file (dev, &dev_attr_scaling_max_freq);
device_remove_file (dev, &dev_attr_scaling_governor);
+ device_remove_file (dev, &dev_attr_scaling_governor);

return 0;
}
@@ -401,20 +447,6 @@
}


-/*
- * cpufreq command line parameter. Must be hard values (kHz)
- * cpufreq=1000000:2000000:PERFORMANCE
- * to set the default CPUFreq policy.
- */
-static int __init cpufreq_setup(char *str)
-{
- cpufreq_parse_policy(str, &default_policy);
- default_policy.cpu = CPUFREQ_ALL_CPUS;
- return 1;
-}
-__setup("cpufreq=", cpufreq_setup);
-
-
/**
* cpufreq_proc_read - read /proc/cpufreq
*
@@ -1202,19 +1234,18 @@
*********************************************************************/

/**
- * cpufreq_register - register a CPU Frequency driver
- * @driver_data: A struct cpufreq_driver containing the values submitted by the CPU Frequency driver.
+ * cpufreq_register_driver - register a CPU Frequency driver
+ * @driver_data: A struct cpufreq_driver containing the values#
+ * submitted by the CPU Frequency driver.
*
* Registers a CPU Frequency driver to this core code. This code
* returns zero on success, -EBUSY when another driver got here first
* (and isn't unregistered in the meantime).
*
*/
-int cpufreq_register(struct cpufreq_driver *driver_data)
+int cpufreq_register_driver(struct cpufreq_driver *driver_data)
{
- unsigned int ret;
- unsigned int i;
- struct cpufreq_policy policy;
+ int ret = 0;

if (cpufreq_driver)
return -EBUSY;
@@ -1224,53 +1255,27 @@
return -EINVAL;

down(&cpufreq_driver_sem);
- cpufreq_driver = driver_data;
-
- /* check for a default policy - if it exists, use it on _all_ CPUs*/
- for (i=0; i<NR_CPUS; i++)
- {
- if (default_policy.policy)
- cpufreq_driver->policy[i].policy = default_policy.policy;
- if (default_policy.min)
- cpufreq_driver->policy[i].min = default_policy.min;
- if (default_policy.max)
- cpufreq_driver->policy[i].max = default_policy.max;
- }

- /* set default policy on all CPUs. Must be called per-CPU and not
- * with CPUFREQ_ALL_CPUs as there might be no common policy for all
- * CPUs (UltraSPARC etc.)
- */
- for (i=0; i<NR_CPUS; i++)
- {
- policy.policy = cpufreq_driver->policy[i].policy;
- policy.min = cpufreq_driver->policy[i].min;
- policy.max = cpufreq_driver->policy[i].max;
- policy.cpu = i;
- up(&cpufreq_driver_sem);
- ret = cpufreq_set_policy(&policy);
- down(&cpufreq_driver_sem);
- if (ret) {
- cpufreq_driver = NULL;
+ cpufreq_driver = driver_data;
+
+ if (!cpufreq_driver->policy) {
+ /* then we need per-CPU init */
+ if (!cpufreq_driver->init) {
up(&cpufreq_driver_sem);
- return ret;
+ return -EINVAL;
+ }
+ cpufreq_driver->policy = kmalloc(NR_CPUS * sizeof(struct cpufreq_policy), GFP_KERNEL);
+ if (!cpufreq_driver->policy) {
+ up(&cpufreq_driver_sem);
+ return -ENOMEM;
}
}
-
+
up(&cpufreq_driver_sem);

cpufreq_proc_init();

#ifdef CONFIG_CPU_FREQ_24_API
- down(&cpufreq_driver_sem);
- for (i=0; i<NR_CPUS; i++)
- {
- cpu_min_freq[i] = driver_data->policy[i].cpuinfo.min_freq;
- cpu_max_freq[i] = driver_data->policy[i].cpuinfo.max_freq;
- cpu_cur_freq[i] = driver_data->cpu_cur_freq[i];
- }
- up(&cpufreq_driver_sem);
-
cpufreq_sysctl_init();
#endif

@@ -1278,40 +1283,53 @@

return ret;
}
-EXPORT_SYMBOL_GPL(cpufreq_register);
+EXPORT_SYMBOL_GPL(cpufreq_register_driver);


/**
- * cpufreq_unregister - unregister the current CPUFreq driver
+ * cpufreq_unregister_driver - unregister the current CPUFreq driver
*
* Unregister the current CPUFreq driver. Only call this if you have
* the right to do so, i.e. if you have succeeded in initialising before!
* Returns zero if successful, and -EINVAL if the cpufreq_driver is
* currently not initialised.
*/
-int cpufreq_unregister(void)
+int cpufreq_unregister_driver(struct cpufreq_driver *driver)
{
down(&cpufreq_driver_sem);

- if (!cpufreq_driver) {
+ if (!cpufreq_driver ||
+ ((driver != cpufreq_driver) && (driver != NULL))) { /* compat */
up(&cpufreq_driver_sem);
return -EINVAL;
}

- interface_unregister(&cpufreq_interface);
- cpufreq_driver = NULL;
-
- up(&cpufreq_driver_sem);
-
cpufreq_proc_exit();

#ifdef CONFIG_CPU_FREQ_24_API
cpufreq_sysctl_exit();
#endif

+ /* remove this workaround as soon as interface_add_data works */
+ {
+ unsigned int i;
+ for (i=0; i<NR_CPUS; i++) {
+ if (cpu_online(i))
+ cpufreq_remove_dev(&cpufreq_driver->policy[i].intf);
+ }
+ }
+
+ interface_unregister(&cpufreq_interface);
+
+ if (driver)
+ kfree(cpufreq_driver->policy);
+ cpufreq_driver = NULL;
+
+ up(&cpufreq_driver_sem);
+
return 0;
}
-EXPORT_SYMBOL_GPL(cpufreq_unregister);
+EXPORT_SYMBOL_GPL(cpufreq_unregister_driver);


#ifdef CONFIG_PM
-
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