![Mike Travis](/assets/img/avatar_default.png)
cpu_data is currently an array defined using NR_CPUS. This means that we overallocate since we will rarely really use maximum configured cpus. When NR_CPU count is raised to 4096 the size of cpu_data becomes 3,145,728 bytes. These changes were adopted from the sparc64 (and ia64) code. An additional field was added to cpuinfo_x86 to be a non-ambiguous cpu index. This corresponds to the index into a cpumask_t as well as the per_cpu index. It's used in various places like show_cpuinfo(). cpu_data is defined to be the boot_cpu_data structure for the NON-SMP case. Signed-off-by: Mike Travis <travis@sgi.com> Acked-by: Christoph Lameter <clameter@sgi.com> Cc: Andi Kleen <ak@suse.de> Cc: James Bottomley <James.Bottomley@steeleye.com> Cc: Dmitry Torokhov <dtor@mail.ru> Cc: "Antonino A. Daplas" <adaplas@pol.net> Cc: Mark M. Hoffman <mhoffman@lightlink.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
191 lines
4.2 KiB
C
191 lines
4.2 KiB
C
/*
|
|
* sc520_freq.c: cpufreq driver for the AMD Elan sc520
|
|
*
|
|
* Copyright (C) 2005 Sean Young <sean@mess.org>
|
|
*
|
|
* 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.
|
|
*
|
|
* Based on elanfreq.c
|
|
*
|
|
* 2005-03-30: - initial revision
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/init.h>
|
|
|
|
#include <linux/delay.h>
|
|
#include <linux/cpufreq.h>
|
|
|
|
#include <asm/msr.h>
|
|
#include <asm/timex.h>
|
|
#include <asm/io.h>
|
|
|
|
#define MMCR_BASE 0xfffef000 /* The default base address */
|
|
#define OFFS_CPUCTL 0x2 /* CPU Control Register */
|
|
|
|
static __u8 __iomem *cpuctl;
|
|
|
|
#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "sc520_freq", msg)
|
|
|
|
static struct cpufreq_frequency_table sc520_freq_table[] = {
|
|
{0x01, 100000},
|
|
{0x02, 133000},
|
|
{0, CPUFREQ_TABLE_END},
|
|
};
|
|
|
|
static unsigned int sc520_freq_get_cpu_frequency(unsigned int cpu)
|
|
{
|
|
u8 clockspeed_reg = *cpuctl;
|
|
|
|
switch (clockspeed_reg & 0x03) {
|
|
default:
|
|
printk(KERN_ERR "sc520_freq: error: cpuctl register has unexpected value %02x\n", clockspeed_reg);
|
|
case 0x01:
|
|
return 100000;
|
|
case 0x02:
|
|
return 133000;
|
|
}
|
|
}
|
|
|
|
static void sc520_freq_set_cpu_state (unsigned int state)
|
|
{
|
|
|
|
struct cpufreq_freqs freqs;
|
|
u8 clockspeed_reg;
|
|
|
|
freqs.old = sc520_freq_get_cpu_frequency(0);
|
|
freqs.new = sc520_freq_table[state].frequency;
|
|
freqs.cpu = 0; /* AMD Elan is UP */
|
|
|
|
cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
|
|
|
|
dprintk("attempting to set frequency to %i kHz\n",
|
|
sc520_freq_table[state].frequency);
|
|
|
|
local_irq_disable();
|
|
|
|
clockspeed_reg = *cpuctl & ~0x03;
|
|
*cpuctl = clockspeed_reg | sc520_freq_table[state].index;
|
|
|
|
local_irq_enable();
|
|
|
|
cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
|
|
};
|
|
|
|
static int sc520_freq_verify (struct cpufreq_policy *policy)
|
|
{
|
|
return cpufreq_frequency_table_verify(policy, &sc520_freq_table[0]);
|
|
}
|
|
|
|
static int sc520_freq_target (struct cpufreq_policy *policy,
|
|
unsigned int target_freq,
|
|
unsigned int relation)
|
|
{
|
|
unsigned int newstate = 0;
|
|
|
|
if (cpufreq_frequency_table_target(policy, sc520_freq_table, target_freq, relation, &newstate))
|
|
return -EINVAL;
|
|
|
|
sc520_freq_set_cpu_state(newstate);
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
/*
|
|
* Module init and exit code
|
|
*/
|
|
|
|
static int sc520_freq_cpu_init(struct cpufreq_policy *policy)
|
|
{
|
|
struct cpuinfo_x86 *c = &cpu_data(0);
|
|
int result;
|
|
|
|
/* capability check */
|
|
if (c->x86_vendor != X86_VENDOR_AMD ||
|
|
c->x86 != 4 || c->x86_model != 9)
|
|
return -ENODEV;
|
|
|
|
/* cpuinfo and default policy values */
|
|
policy->cpuinfo.transition_latency = 1000000; /* 1ms */
|
|
policy->cur = sc520_freq_get_cpu_frequency(0);
|
|
|
|
result = cpufreq_frequency_table_cpuinfo(policy, sc520_freq_table);
|
|
if (result)
|
|
return (result);
|
|
|
|
cpufreq_frequency_table_get_attr(sc520_freq_table, policy->cpu);
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
static int sc520_freq_cpu_exit(struct cpufreq_policy *policy)
|
|
{
|
|
cpufreq_frequency_table_put_attr(policy->cpu);
|
|
return 0;
|
|
}
|
|
|
|
|
|
static struct freq_attr* sc520_freq_attr[] = {
|
|
&cpufreq_freq_attr_scaling_available_freqs,
|
|
NULL,
|
|
};
|
|
|
|
|
|
static struct cpufreq_driver sc520_freq_driver = {
|
|
.get = sc520_freq_get_cpu_frequency,
|
|
.verify = sc520_freq_verify,
|
|
.target = sc520_freq_target,
|
|
.init = sc520_freq_cpu_init,
|
|
.exit = sc520_freq_cpu_exit,
|
|
.name = "sc520_freq",
|
|
.owner = THIS_MODULE,
|
|
.attr = sc520_freq_attr,
|
|
};
|
|
|
|
|
|
static int __init sc520_freq_init(void)
|
|
{
|
|
struct cpuinfo_x86 *c = &cpu_data(0);
|
|
int err;
|
|
|
|
/* Test if we have the right hardware */
|
|
if(c->x86_vendor != X86_VENDOR_AMD ||
|
|
c->x86 != 4 || c->x86_model != 9) {
|
|
dprintk("no Elan SC520 processor found!\n");
|
|
return -ENODEV;
|
|
}
|
|
cpuctl = ioremap((unsigned long)(MMCR_BASE + OFFS_CPUCTL), 1);
|
|
if(!cpuctl) {
|
|
printk(KERN_ERR "sc520_freq: error: failed to remap memory\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
err = cpufreq_register_driver(&sc520_freq_driver);
|
|
if (err)
|
|
iounmap(cpuctl);
|
|
|
|
return err;
|
|
}
|
|
|
|
|
|
static void __exit sc520_freq_exit(void)
|
|
{
|
|
cpufreq_unregister_driver(&sc520_freq_driver);
|
|
iounmap(cpuctl);
|
|
}
|
|
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_AUTHOR("Sean Young <sean@mess.org>");
|
|
MODULE_DESCRIPTION("cpufreq driver for AMD's Elan sc520 CPU");
|
|
|
|
module_init(sc520_freq_init);
|
|
module_exit(sc520_freq_exit);
|
|
|