ACPI, cpuidle: Clarify C-state description in sysfs

Add a new sysfs entry under cpuidle states. desc - can be used by driver to
communicate to userspace any specific information about the state.
This helps in identifying the exact hardware C-states behind the ACPI C-state
definition.

Idea is to export this through powertop, which will help to map the C-state
reported by powertop to actual hardware C-state.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

diff --git a/arch/x86/kernel/acpi/cstate.c b/arch/x86/kernel/acpi/cstate.c
index 10b6717..8ca3557 100644 (file)
--- a/arch/x86/kernel/acpi/cstate.c
+++ b/arch/x86/kernel/acpi/cstate.c
@@ -126,6 +126,8 @@ int acpi_processor_ffh_cstate_probe(unsigned int cpu,
                printk(KERN_DEBUG "Monitor-Mwait will be used to enter C-%d "
                       "state\n", cx->type);
        }
+       snprintf(cx->desc, ACPI_CX_DESC_LEN, "ACPI FFH INTEL MWAIT 0x%x",
+                cx->address);
 
 out:
        set_cpus_allowed(current, saved_mask);

diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 32003fd..baa389b 100644 (file)
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -945,11 +945,16 @@ static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
                                 * Otherwise, ignore this info and continue.
                                 */
                                cx.entry_method = ACPI_CSTATE_HALT;
+                               snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
                        } else {
                                continue;
                        }
+               } else {
+                       snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
+                                cx.address);
                }
 
+
                obj = &(element->package.elements[2]);
                if (obj->type != ACPI_TYPE_INTEGER)
                        continue;
@@ -1643,6 +1648,11 @@ static int acpi_processor_setup_cpuidle(struct acpi_processor *pr)
                return -EINVAL;
        }
 
+       for (i = 0; i < CPUIDLE_STATE_MAX; i++) {
+               dev->states[i].name[0] = '\0';
+               dev->states[i].desc[0] = '\0';
+       }
+
        for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
                cx = &pr->power.states[i];
                state = &dev->states[count];
@@ -1659,6 +1669,7 @@ static int acpi_processor_setup_cpuidle(struct acpi_processor *pr)
                cpuidle_set_statedata(state, cx);
 
                snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
+               strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
                state->exit_latency = cx->latency;
                state->target_residency = cx->latency * latency_factor;
                state->power_usage = cx->power;

diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index 60f71e6..d73663a 100644 (file)
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -219,7 +219,8 @@ static void poll_idle_init(struct cpuidle_device *dev)
 
        cpuidle_set_statedata(state, NULL);
 
-       snprintf(state->name, CPUIDLE_NAME_LEN, "C0 (poll idle)");
+       snprintf(state->name, CPUIDLE_NAME_LEN, "C0");
+       snprintf(state->desc, CPUIDLE_DESC_LEN, "CPUIDLE CORE POLL IDLE");
        state->exit_latency = 0;
        state->target_residency = 0;
        state->power_usage = -1;

diff --git a/drivers/cpuidle/sysfs.c b/drivers/cpuidle/sysfs.c
index 088ea74..69102ca 100644 (file)
--- a/drivers/cpuidle/sysfs.c
+++ b/drivers/cpuidle/sysfs.c
@@ -218,16 +218,23 @@ static ssize_t show_state_##_name(struct cpuidle_state *state, char *buf) \
        return sprintf(buf, "%u\n", state->_name);\
 }
 
-static ssize_t show_state_name(struct cpuidle_state *state, char *buf)
-{
-       return sprintf(buf, "%s\n", state->name);
+#define define_show_state_str_function(_name) \
+static ssize_t show_state_##_name(struct cpuidle_state *state, char *buf) \
+{ \
+       if (state->_name[0] == '\0')\
+               return sprintf(buf, "<null>\n");\
+       return sprintf(buf, "%s\n", state->_name);\
 }
 
 define_show_state_function(exit_latency)
 define_show_state_function(power_usage)
 define_show_state_function(usage)
 define_show_state_function(time)
+define_show_state_str_function(name)
+define_show_state_str_function(desc)
+
 define_one_state_ro(name, show_state_name);
+define_one_state_ro(desc, show_state_desc);
 define_one_state_ro(latency, show_state_exit_latency);
 define_one_state_ro(power, show_state_power_usage);
 define_one_state_ro(usage, show_state_usage);
@@ -235,6 +242,7 @@ define_one_state_ro(time, show_state_time);
 
 static struct attribute *cpuidle_state_default_attrs[] = {
        &attr_name.attr,
+       &attr_desc.attr,
        &attr_latency.attr,
        &attr_power.attr,
        &attr_usage.attr,

diff --git a/include/acpi/processor.h b/include/acpi/processor.h
index cdc8004..06480bc 100644 (file)
--- a/include/acpi/processor.h
+++ b/include/acpi/processor.h
@@ -32,9 +32,11 @@
 #define DOMAIN_COORD_TYPE_SW_ANY       0xfd
 #define DOMAIN_COORD_TYPE_HW_ALL       0xfe
 
-#define ACPI_CSTATE_SYSTEMIO   (0)
-#define ACPI_CSTATE_FFH                (1)
-#define ACPI_CSTATE_HALT       (2)
+#define ACPI_CSTATE_SYSTEMIO   0
+#define ACPI_CSTATE_FFH                1
+#define ACPI_CSTATE_HALT       2
+
+#define ACPI_CX_DESC_LEN       32
 
 /* Power Management */
 
@@ -74,6 +76,7 @@ struct acpi_processor_cx {
        u64 time;
        struct acpi_processor_cx_policy promotion;
        struct acpi_processor_cx_policy demotion;
+       char desc[ACPI_CX_DESC_LEN];
 };
 
 struct acpi_processor_power {

diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
index 385d45b..6b72a45 100644 (file)
--- a/include/linux/cpuidle.h
+++ b/include/linux/cpuidle.h
@@ -19,6 +19,7 @@
 
 #define CPUIDLE_STATE_MAX      8
 #define CPUIDLE_NAME_LEN       16
+#define CPUIDLE_DESC_LEN       32
 
 struct cpuidle_device;
 
@@ -29,6 +30,7 @@ struct cpuidle_device;
 
 struct cpuidle_state {
        char            name[CPUIDLE_NAME_LEN];
+       char            desc[CPUIDLE_DESC_LEN];
        void            *driver_data;
 
        unsigned int    flags;