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[CPUFREQ][3/8] acpi-cpufreq: Pull in MSR based transition support
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Add in the support for Intel Enhanced Speedstep - MSR based transitions.
With this change, the ACPI based support in speedstep-centrino can be
deprecated and duplicate code in that driver can be marked for removal.
Much easier to maintain and support this way. This also reduces the
user misconfigurations and questions on which driver is to be used
under which CPUs to support Enhanced Speedstep.

Signed-off-by: Denis Sadykov <denis.m.sadykov@intel.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
Signed-off-by: Dave Jones <davej@redhat.com>
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Venkatesh Pallipadi authored and Dave Jones committed Oct 15, 2006
1 parent fe27cb3 commit dde9f7b
Showing 1 changed file with 139 additions and 16 deletions.
155 changes: 139 additions & 16 deletions arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c
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Original file line number Diff line number Diff line change
Expand Up @@ -39,6 +39,7 @@
#include <acpi/processor.h>

#include <asm/io.h>
#include <asm/msr.h>
#include <asm/processor.h>
#include <asm/cpufeature.h>
#include <asm/delay.h>
Expand All @@ -51,10 +52,19 @@ MODULE_DESCRIPTION("ACPI Processor P-States Driver");
MODULE_LICENSE("GPL");


enum {
UNDEFINED_CAPABLE = 0,
SYSTEM_INTEL_MSR_CAPABLE,
SYSTEM_IO_CAPABLE,
};

#define INTEL_MSR_RANGE (0xffff)

struct acpi_cpufreq_data {
struct acpi_processor_performance *acpi_data;
struct cpufreq_frequency_table *freq_table;
unsigned int resume;
unsigned int cpu_feature;
};

static struct acpi_cpufreq_data *drv_data[NR_CPUS];
Expand All @@ -64,7 +74,20 @@ static struct cpufreq_driver acpi_cpufreq_driver;

static unsigned int acpi_pstate_strict;

static unsigned extract_freq(u32 value, struct acpi_cpufreq_data *data)

static int check_est_cpu(unsigned int cpuid)
{
struct cpuinfo_x86 *cpu = &cpu_data[cpuid];

if (cpu->x86_vendor != X86_VENDOR_INTEL ||
!cpu_has(cpu, X86_FEATURE_EST))
return 0;

return 1;
}


static unsigned extract_io(u32 value, struct acpi_cpufreq_data *data)
{
struct acpi_processor_performance *perf;
int i;
Expand All @@ -79,6 +102,31 @@ static unsigned extract_freq(u32 value, struct acpi_cpufreq_data *data)
}


static unsigned extract_msr(u32 msr, struct acpi_cpufreq_data *data)
{
int i;

msr &= INTEL_MSR_RANGE;
for (i = 0; data->freq_table[i].frequency != CPUFREQ_TABLE_END; i++) {
if (msr == data->freq_table[i].index)
return data->freq_table[i].frequency;
}
return data->freq_table[0].frequency;
}


static unsigned extract_freq(u32 val, struct acpi_cpufreq_data *data)
{
switch (data->cpu_feature) {
case SYSTEM_INTEL_MSR_CAPABLE:
return extract_msr(val, data);
case SYSTEM_IO_CAPABLE:
return extract_io(val, data);
default:
return 0;
}
}

static void wrport(u16 port, u8 bit_width, u32 value)
{
if (bit_width <= 8) {
Expand All @@ -102,27 +150,57 @@ static void rdport(u16 port, u8 bit_width, u32 *ret)
}
}

struct msr_addr {
u32 reg;
};

struct io_addr {
u16 port;
u8 bit_width;
};

typedef union {
struct msr_addr msr;
struct io_addr io;
} drv_addr_union;

struct drv_cmd {
unsigned int type;
cpumask_t mask;
struct io_addr addr;
drv_addr_union addr;
u32 val;
};

static void do_drv_read(struct drv_cmd *cmd)
{
rdport(cmd->addr.port, cmd->addr.bit_width, &cmd->val);
return;
u32 h;

switch (cmd->type) {
case SYSTEM_INTEL_MSR_CAPABLE:
rdmsr(cmd->addr.msr.reg, cmd->val, h);
break;
case SYSTEM_IO_CAPABLE:
rdport(cmd->addr.io.port, cmd->addr.io.bit_width, &cmd->val);
break;
default:
break;
}
}

static void do_drv_write(struct drv_cmd *cmd)
{
wrport(cmd->addr.port, cmd->addr.bit_width, cmd->val);
return;
u32 h = 0;

switch (cmd->type) {
case SYSTEM_INTEL_MSR_CAPABLE:
wrmsr(cmd->addr.msr.reg, cmd->val, h);
break;
case SYSTEM_IO_CAPABLE:
wrport(cmd->addr.io.port, cmd->addr.io.bit_width, cmd->val);
break;
default:
break;
}
}

static inline void drv_read(struct drv_cmd *cmd)
Expand Down Expand Up @@ -158,9 +236,21 @@ static u32 get_cur_val(cpumask_t mask)
if (unlikely(cpus_empty(mask)))
return 0;

perf = drv_data[first_cpu(mask)]->acpi_data;
cmd.addr.port = perf->control_register.address;
cmd.addr.bit_width = perf->control_register.bit_width;
switch (drv_data[first_cpu(mask)]->cpu_feature) {
case SYSTEM_INTEL_MSR_CAPABLE:
cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
cmd.addr.msr.reg = MSR_IA32_PERF_STATUS;
break;
case SYSTEM_IO_CAPABLE:
cmd.type = SYSTEM_IO_CAPABLE;
perf = drv_data[first_cpu(mask)]->acpi_data;
cmd.addr.io.port = perf->control_register.address;
cmd.addr.io.bit_width = perf->control_register.bit_width;
break;
default:
return 0;
}

cmd.mask = mask;

drv_read(&cmd);
Expand Down Expand Up @@ -213,6 +303,7 @@ static int acpi_cpufreq_target(struct cpufreq_policy *policy,
struct cpufreq_freqs freqs;
cpumask_t online_policy_cpus;
struct drv_cmd cmd;
unsigned int msr;
unsigned int next_state = 0;
unsigned int next_perf_state = 0;
unsigned int i;
Expand Down Expand Up @@ -256,9 +347,22 @@ static int acpi_cpufreq_target(struct cpufreq_policy *policy,
}
}

cmd.addr.port = perf->control_register.address;
cmd.addr.bit_width = perf->control_register.bit_width;
cmd.val = (u32) perf->states[next_perf_state].control;
switch (data->cpu_feature) {
case SYSTEM_INTEL_MSR_CAPABLE:
cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
cmd.addr.msr.reg = MSR_IA32_PERF_CTL;
msr = (u32) perf->states[next_perf_state].control & INTEL_MSR_RANGE;
cmd.val = (cmd.val & ~INTEL_MSR_RANGE) | msr;
break;
case SYSTEM_IO_CAPABLE:
cmd.type = SYSTEM_IO_CAPABLE;
cmd.addr.io.port = perf->control_register.address;
cmd.addr.io.bit_width = perf->control_register.bit_width;
cmd.val = (u32) perf->states[next_perf_state].control;
break;
default:
return -ENODEV;
}

cpus_clear(cmd.mask);

Expand Down Expand Up @@ -405,6 +509,7 @@ acpi_cpufreq_cpu_init (
unsigned int valid_states = 0;
unsigned int cpu = policy->cpu;
struct acpi_cpufreq_data *data;
unsigned int l, h;
unsigned int result = 0;
struct cpuinfo_x86 *c = &cpu_data[policy->cpu];
struct acpi_processor_performance *perf;
Expand Down Expand Up @@ -463,6 +568,15 @@ acpi_cpufreq_cpu_init (
switch (perf->control_register.space_id) {
case ACPI_ADR_SPACE_SYSTEM_IO:
dprintk("SYSTEM IO addr space\n");
data->cpu_feature = SYSTEM_IO_CAPABLE;
break;
case ACPI_ADR_SPACE_FIXED_HARDWARE:
dprintk("HARDWARE addr space\n");
if (!check_est_cpu(cpu)) {
result = -ENODEV;
goto err_unreg;
}
data->cpu_feature = SYSTEM_INTEL_MSR_CAPABLE;
break;
default:
dprintk("Unknown addr space %d\n",
Expand All @@ -485,9 +599,6 @@ acpi_cpufreq_cpu_init (
}
policy->governor = CPUFREQ_DEFAULT_GOVERNOR;

/* The current speed is unknown and not detectable by ACPI... */
policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);

/* table init */
for (i=0; i<perf->state_count; i++)
{
Expand All @@ -507,6 +618,18 @@ acpi_cpufreq_cpu_init (
goto err_freqfree;
}

switch (data->cpu_feature) {
case ACPI_ADR_SPACE_SYSTEM_IO:
/* Current speed is unknown and not detectable by IO port */
policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
break;
case ACPI_ADR_SPACE_FIXED_HARDWARE:
get_cur_freq_on_cpu(cpu);
break;
default:
break;
}

/* notify BIOS that we exist */
acpi_processor_notify_smm(THIS_MODULE);

Expand Down Expand Up @@ -599,7 +722,7 @@ acpi_cpufreq_init (void)

acpi_cpufreq_early_init();

return cpufreq_register_driver(&acpi_cpufreq_driver);
return cpufreq_register_driver(&acpi_cpufreq_driver);
}


Expand Down

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