apm_power: calculate to_full/to_empty time using energy

[pandora-kernel.git] / arch / i386 / kernel / acpi / cstate.c

diff --git a/arch/i386/kernel/acpi/cstate.c b/arch/i386/kernel/acpi/cstate.c
index 25db49e..2d39f55 100644 (file)
--- a/arch/i386/kernel/acpi/cstate.c
+++ b/arch/i386/kernel/acpi/cstate.c
@@ -10,6 +10,8 @@
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/acpi.h>
+#include <linux/cpu.h>
+#include <linux/sched.h>
 
 #include <acpi/processor.h>
 #include <asm/acpi.h>
@@ -41,5 +43,122 @@ void acpi_processor_power_init_bm_check(struct acpi_processor_flags *flags,
                flags->bm_check = 1;
        }
 }
-
 EXPORT_SYMBOL(acpi_processor_power_init_bm_check);
+
+/* The code below handles cstate entry with monitor-mwait pair on Intel*/
+
+struct cstate_entry {
+       struct {
+               unsigned int eax;
+               unsigned int ecx;
+       } states[ACPI_PROCESSOR_MAX_POWER];
+};
+static struct cstate_entry *cpu_cstate_entry;  /* per CPU ptr */
+
+static short mwait_supported[ACPI_PROCESSOR_MAX_POWER];
+
+#define MWAIT_SUBSTATE_MASK    (0xf)
+#define MWAIT_SUBSTATE_SIZE    (4)
+
+#define CPUID_MWAIT_LEAF (5)
+#define CPUID5_ECX_EXTENSIONS_SUPPORTED (0x1)
+#define CPUID5_ECX_INTERRUPT_BREAK     (0x2)
+
+#define MWAIT_ECX_INTERRUPT_BREAK      (0x1)
+
+#define NATIVE_CSTATE_BEYOND_HALT      (2)
+
+int acpi_processor_ffh_cstate_probe(unsigned int cpu,
+               struct acpi_processor_cx *cx, struct acpi_power_register *reg)
+{
+       struct cstate_entry *percpu_entry;
+       struct cpuinfo_x86 *c = cpu_data + cpu;
+
+       cpumask_t saved_mask;
+       int retval;
+       unsigned int eax, ebx, ecx, edx;
+       unsigned int edx_part;
+       unsigned int cstate_type; /* C-state type and not ACPI C-state type */
+       unsigned int num_cstate_subtype;
+
+       if (!cpu_cstate_entry || c->cpuid_level < CPUID_MWAIT_LEAF )
+               return -1;
+
+       if (reg->bit_offset != NATIVE_CSTATE_BEYOND_HALT)
+               return -1;
+
+       percpu_entry = per_cpu_ptr(cpu_cstate_entry, cpu);
+       percpu_entry->states[cx->index].eax = 0;
+       percpu_entry->states[cx->index].ecx = 0;
+
+       /* Make sure we are running on right CPU */
+       saved_mask = current->cpus_allowed;
+       retval = set_cpus_allowed(current, cpumask_of_cpu(cpu));
+       if (retval)
+               return -1;
+
+       cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &edx);
+
+       /* Check whether this particular cx_type (in CST) is supported or not */
+       cstate_type = (cx->address >> MWAIT_SUBSTATE_SIZE) + 1;
+       edx_part = edx >> (cstate_type * MWAIT_SUBSTATE_SIZE);
+       num_cstate_subtype = edx_part & MWAIT_SUBSTATE_MASK;
+
+       retval = 0;
+       if (num_cstate_subtype < (cx->address & MWAIT_SUBSTATE_MASK)) {
+               retval = -1;
+               goto out;
+       }
+
+       /* mwait ecx extensions INTERRUPT_BREAK should be supported for C2/C3 */
+       if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) ||
+           !(ecx & CPUID5_ECX_INTERRUPT_BREAK)) {
+               retval = -1;
+               goto out;
+       }
+       percpu_entry->states[cx->index].ecx = MWAIT_ECX_INTERRUPT_BREAK;
+
+       /* Use the hint in CST */
+       percpu_entry->states[cx->index].eax = cx->address;
+
+       if (!mwait_supported[cstate_type]) {
+               mwait_supported[cstate_type] = 1;
+               printk(KERN_DEBUG "Monitor-Mwait will be used to enter C-%d "
+                      "state\n", cx->type);
+       }
+
+out:
+       set_cpus_allowed(current, saved_mask);
+       return retval;
+}
+EXPORT_SYMBOL_GPL(acpi_processor_ffh_cstate_probe);
+
+void acpi_processor_ffh_cstate_enter(struct acpi_processor_cx *cx)
+{
+       unsigned int cpu = smp_processor_id();
+       struct cstate_entry *percpu_entry;
+
+       percpu_entry = per_cpu_ptr(cpu_cstate_entry, cpu);
+       mwait_idle_with_hints(percpu_entry->states[cx->index].eax,
+                             percpu_entry->states[cx->index].ecx);
+}
+EXPORT_SYMBOL_GPL(acpi_processor_ffh_cstate_enter);
+
+static int __init ffh_cstate_init(void)
+{
+       struct cpuinfo_x86 *c = &boot_cpu_data;
+       if (c->x86_vendor != X86_VENDOR_INTEL)
+               return -1;
+
+       cpu_cstate_entry = alloc_percpu(struct cstate_entry);
+       return 0;
+}
+
+static void __exit ffh_cstate_exit(void)
+{
+       free_percpu(cpu_cstate_entry);
+       cpu_cstate_entry = NULL;
+}
+
+arch_initcall(ffh_cstate_init);
+__exitcall(ffh_cstate_exit);