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-rw-r--r--arch/i386/kernel/acpi/cstate.c122
-rw-r--r--arch/i386/kernel/process.c22
-rw-r--r--arch/x86_64/kernel/process.c22
-rw-r--r--drivers/acpi/processor_idle.c101
-rw-r--r--include/acpi/pdc_intel.h9
-rw-r--r--include/acpi/processor.h18
-rw-r--r--include/asm-i386/processor.h2
-rw-r--r--include/asm-x86_64/processor.h2
8 files changed, 242 insertions, 56 deletions
diff --git a/arch/i386/kernel/acpi/cstate.c b/arch/i386/kernel/acpi/cstate.c
index 25db49ef1770..20563e52c622 100644
--- a/arch/i386/kernel/acpi/cstate.c
+++ b/arch/i386/kernel/acpi/cstate.c
@@ -10,6 +10,7 @@
#include <linux/module.h>
#include <linux/init.h>
#include <linux/acpi.h>
+#include <linux/cpu.h>
#include <acpi/processor.h>
#include <asm/acpi.h>
@@ -41,5 +42,124 @@ 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_s {
+ struct {
+ unsigned int eax;
+ unsigned int ecx;
+ } states[ACPI_PROCESSOR_MAX_POWER];
+};
+static struct cstate_entry_s *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_s *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_s *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_s);
+ return 0;
+}
+
+static void __exit ffh_cstate_exit(void)
+{
+ if (cpu_cstate_entry) {
+ free_percpu(cpu_cstate_entry);
+ cpu_cstate_entry = NULL;
+ }
+}
+
+arch_initcall(ffh_cstate_init);
+__exitcall(ffh_cstate_exit);
diff --git a/arch/i386/kernel/process.c b/arch/i386/kernel/process.c
index b0a07801d9df..57d375900afb 100644
--- a/arch/i386/kernel/process.c
+++ b/arch/i386/kernel/process.c
@@ -236,20 +236,28 @@ EXPORT_SYMBOL_GPL(cpu_idle_wait);
* We execute MONITOR against need_resched and enter optimized wait state
* through MWAIT. Whenever someone changes need_resched, we would be woken
* up from MWAIT (without an IPI).
+ *
+ * New with Core Duo processors, MWAIT can take some hints based on CPU
+ * capability.
*/
-static void mwait_idle(void)
+void mwait_idle_with_hints(unsigned long eax, unsigned long ecx)
{
- local_irq_enable();
-
- while (!need_resched()) {
+ if (!need_resched()) {
__monitor((void *)&current_thread_info()->flags, 0, 0);
smp_mb();
- if (need_resched())
- break;
- __mwait(0, 0);
+ if (!need_resched())
+ __mwait(eax, ecx);
}
}
+/* Default MONITOR/MWAIT with no hints, used for default C1 state */
+static void mwait_idle(void)
+{
+ local_irq_enable();
+ while (!need_resched())
+ mwait_idle_with_hints(0, 0);
+}
+
void __devinit select_idle_routine(const struct cpuinfo_x86 *c)
{
if (cpu_has(c, X86_FEATURE_MWAIT)) {
diff --git a/arch/x86_64/kernel/process.c b/arch/x86_64/kernel/process.c
index 5e95b257ee26..49f7fac6229e 100644
--- a/arch/x86_64/kernel/process.c
+++ b/arch/x86_64/kernel/process.c
@@ -238,20 +238,28 @@ void cpu_idle (void)
* We execute MONITOR against need_resched and enter optimized wait state
* through MWAIT. Whenever someone changes need_resched, we would be woken
* up from MWAIT (without an IPI).
+ *
+ * New with Core Duo processors, MWAIT can take some hints based on CPU
+ * capability.
*/
-static void mwait_idle(void)
+void mwait_idle_with_hints(unsigned long eax, unsigned long ecx)
{
- local_irq_enable();
-
- while (!need_resched()) {
+ if (!need_resched()) {
__monitor((void *)&current_thread_info()->flags, 0, 0);
smp_mb();
- if (need_resched())
- break;
- __mwait(0, 0);
+ if (!need_resched())
+ __mwait(eax, ecx);
}
}
+/* Default MONITOR/MWAIT with no hints, used for default C1 state */
+static void mwait_idle(void)
+{
+ local_irq_enable();
+ while (!need_resched())
+ mwait_idle_with_hints(0,0);
+}
+
void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c)
{
static int printed;
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 0a395fca843b..429a39dbd75d 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -219,6 +219,23 @@ static void acpi_safe_halt(void)
static atomic_t c3_cpu_count;
+/* Common C-state entry for C2, C3, .. */
+static void acpi_cstate_enter(struct acpi_processor_cx *cstate)
+{
+ if (cstate->space_id == ACPI_CSTATE_FFH) {
+ /* Call into architectural FFH based C-state */
+ acpi_processor_ffh_cstate_enter(cstate);
+ } else {
+ int unused;
+ /* IO port based C-state */
+ inb(cstate->address);
+ /* Dummy wait op - must do something useless after P_LVL2 read
+ because chipsets cannot guarantee that STPCLK# signal
+ gets asserted in time to freeze execution properly. */
+ unused = inl(acpi_fadt.xpm_tmr_blk.address);
+ }
+}
+
static void acpi_processor_idle(void)
{
struct acpi_processor *pr = NULL;
@@ -361,11 +378,7 @@ static void acpi_processor_idle(void)
/* Get start time (ticks) */
t1 = inl(acpi_fadt.xpm_tmr_blk.address);
/* Invoke C2 */
- inb(cx->address);
- /* Dummy wait op - must do something useless after P_LVL2 read
- because chipsets cannot guarantee that STPCLK# signal
- gets asserted in time to freeze execution properly. */
- t2 = inl(acpi_fadt.xpm_tmr_blk.address);
+ acpi_cstate_enter(cx);
/* Get end time (ticks) */
t2 = inl(acpi_fadt.xpm_tmr_blk.address);
@@ -401,9 +414,7 @@ static void acpi_processor_idle(void)
/* Get start time (ticks) */
t1 = inl(acpi_fadt.xpm_tmr_blk.address);
/* Invoke C3 */
- inb(cx->address);
- /* Dummy wait op (see above) */
- t2 = inl(acpi_fadt.xpm_tmr_blk.address);
+ acpi_cstate_enter(cx);
/* Get end time (ticks) */
t2 = inl(acpi_fadt.xpm_tmr_blk.address);
if (pr->flags.bm_check) {
@@ -628,20 +639,16 @@ static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
return 0;
}
-static int acpi_processor_get_power_info_default_c1(struct acpi_processor *pr)
+static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
{
-
- /* Zero initialize all the C-states info. */
- memset(pr->power.states, 0, sizeof(pr->power.states));
-
- /* set the first C-State to C1 */
- pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
-
- /* the C0 state only exists as a filler in our array,
- * and all processors need to support C1 */
+ if (!pr->power.states[ACPI_STATE_C1].valid) {
+ /* set the first C-State to C1 */
+ /* all processors need to support C1 */
+ pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
+ pr->power.states[ACPI_STATE_C1].valid = 1;
+ }
+ /* the C0 state only exists as a filler in our array */
pr->power.states[ACPI_STATE_C0].valid = 1;
- pr->power.states[ACPI_STATE_C1].valid = 1;
-
return 0;
}
@@ -658,12 +665,7 @@ static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
if (nocst)
return -ENODEV;
- current_count = 1;
-
- /* Zero initialize C2 onwards and prepare for fresh CST lookup */
- for (i = 2; i < ACPI_PROCESSOR_MAX_POWER; i++)
- memset(&(pr->power.states[i]), 0,
- sizeof(struct acpi_processor_cx));
+ current_count = 0;
status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
if (ACPI_FAILURE(status)) {
@@ -718,22 +720,39 @@ static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
(reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
continue;
- cx.address = (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) ?
- 0 : reg->address;
-
/* There should be an easy way to extract an integer... */
obj = (union acpi_object *)&(element->package.elements[1]);
if (obj->type != ACPI_TYPE_INTEGER)
continue;
cx.type = obj->integer.value;
-
- if ((cx.type != ACPI_STATE_C1) &&
- (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO))
- continue;
-
- if ((cx.type < ACPI_STATE_C2) || (cx.type > ACPI_STATE_C3))
- continue;
+ /*
+ * Some buggy BIOSes won't list C1 in _CST -
+ * Let acpi_processor_get_power_info_default() handle them later
+ */
+ if (i == 1 && cx.type != ACPI_STATE_C1)
+ current_count++;
+
+ cx.address = reg->address;
+ cx.index = current_count + 1;
+
+ cx.space_id = ACPI_CSTATE_SYSTEMIO;
+ if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
+ if (acpi_processor_ffh_cstate_probe
+ (pr->id, &cx, reg) == 0) {
+ cx.space_id = ACPI_CSTATE_FFH;
+ } else if (cx.type != ACPI_STATE_C1) {
+ /*
+ * C1 is a special case where FIXED_HARDWARE
+ * can be handled in non-MWAIT way as well.
+ * In that case, save this _CST entry info.
+ * That is, we retain space_id of SYSTEM_IO for
+ * halt based C1.
+ * Otherwise, ignore this info and continue.
+ */
+ continue;
+ }
+ }
obj = (union acpi_object *)&(element->package.elements[2]);
if (obj->type != ACPI_TYPE_INTEGER)
@@ -938,12 +957,18 @@ static int acpi_processor_get_power_info(struct acpi_processor *pr)
/* NOTE: the idle thread may not be running while calling
* this function */
- /* Adding C1 state */
- acpi_processor_get_power_info_default_c1(pr);
+ /* Zero initialize all the C-states info. */
+ memset(pr->power.states, 0, sizeof(pr->power.states));
+
result = acpi_processor_get_power_info_cst(pr);
if (result == -ENODEV)
acpi_processor_get_power_info_fadt(pr);
+ if (result)
+ return result;
+
+ acpi_processor_get_power_info_default(pr);
+
pr->power.count = acpi_processor_power_verify(pr);
/*
diff --git a/include/acpi/pdc_intel.h b/include/acpi/pdc_intel.h
index c5472be6f3a2..e72bfdd887f9 100644
--- a/include/acpi/pdc_intel.h
+++ b/include/acpi/pdc_intel.h
@@ -13,6 +13,7 @@
#define ACPI_PDC_SMP_C_SWCOORD (0x0040)
#define ACPI_PDC_SMP_T_SWCOORD (0x0080)
#define ACPI_PDC_C_C1_FFH (0x0100)
+#define ACPI_PDC_C_C2C3_FFH (0x0200)
#define ACPI_PDC_EST_CAPABILITY_SMP (ACPI_PDC_SMP_C1PT | \
ACPI_PDC_C_C1_HALT | \
@@ -23,8 +24,10 @@
ACPI_PDC_SMP_P_SWCOORD | \
ACPI_PDC_P_FFH)
-#define ACPI_PDC_C_CAPABILITY_SMP (ACPI_PDC_SMP_C2C3 | \
- ACPI_PDC_SMP_C1PT | \
- ACPI_PDC_C_C1_HALT)
+#define ACPI_PDC_C_CAPABILITY_SMP (ACPI_PDC_SMP_C2C3 | \
+ ACPI_PDC_SMP_C1PT | \
+ ACPI_PDC_C_C1_HALT | \
+ ACPI_PDC_C_C1_FFH | \
+ ACPI_PDC_C_C2C3_FFH)
#endif /* __PDC_INTEL_H__ */
diff --git a/include/acpi/processor.h b/include/acpi/processor.h
index 9dd5b75961f8..7798d2a9f793 100644
--- a/include/acpi/processor.h
+++ b/include/acpi/processor.h
@@ -29,6 +29,9 @@
#define DOMAIN_COORD_TYPE_SW_ANY 0xfd
#define DOMAIN_COORD_TYPE_HW_ALL 0xfe
+#define ACPI_CSTATE_SYSTEMIO (0)
+#define ACPI_CSTATE_FFH (1)
+
/* Power Management */
struct acpi_processor_cx;
@@ -58,6 +61,8 @@ struct acpi_processor_cx {
u8 valid;
u8 type;
u32 address;
+ u8 space_id;
+ u8 index;
u32 latency;
u32 latency_ticks;
u32 power;
@@ -206,6 +211,9 @@ void arch_acpi_processor_init_pdc(struct acpi_processor *pr);
#ifdef ARCH_HAS_POWER_INIT
void acpi_processor_power_init_bm_check(struct acpi_processor_flags *flags,
unsigned int cpu);
+int acpi_processor_ffh_cstate_probe(unsigned int cpu,
+ struct acpi_processor_cx *cx, struct acpi_power_register *reg);
+void acpi_processor_ffh_cstate_enter(struct acpi_processor_cx *cstate);
#else
static inline void acpi_processor_power_init_bm_check(struct
acpi_processor_flags
@@ -214,6 +222,16 @@ static inline void acpi_processor_power_init_bm_check(struct
flags->bm_check = 1;
return;
}
+static inline int acpi_processor_ffh_cstate_probe(unsigned int cpu,
+ struct acpi_processor_cx *cx, struct acpi_power_register *reg)
+{
+ return -1;
+}
+static inline void acpi_processor_ffh_cstate_enter(
+ struct acpi_processor_cx *cstate)
+{
+ return;
+}
#endif
/* in processor_perflib.c */
diff --git a/include/asm-i386/processor.h b/include/asm-i386/processor.h
index 2277127696d2..e0ddca94d50c 100644
--- a/include/asm-i386/processor.h
+++ b/include/asm-i386/processor.h
@@ -306,6 +306,8 @@ static inline void __mwait(unsigned long eax, unsigned long ecx)
: :"a" (eax), "c" (ecx));
}
+extern void mwait_idle_with_hints(unsigned long eax, unsigned long ecx);
+
/* from system description table in BIOS. Mostly for MCA use, but
others may find it useful. */
extern unsigned int machine_id;
diff --git a/include/asm-x86_64/processor.h b/include/asm-x86_64/processor.h
index de9c3147ee4c..cef17e0f828c 100644
--- a/include/asm-x86_64/processor.h
+++ b/include/asm-x86_64/processor.h
@@ -475,6 +475,8 @@ static inline void __mwait(unsigned long eax, unsigned long ecx)
: :"a" (eax), "c" (ecx));
}
+extern void mwait_idle_with_hints(unsigned long eax, unsigned long ecx);
+
#define stack_current() \
({ \
struct thread_info *ti; \
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.