From: "Rafael J. Wysocki" rafael.j.wysocki@intel.com
mainline inclusion from mainline-v5.6-rc1 commit 18734958e9bfbc055805d110a38dc76307eba742 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I47H3V CVE: NA
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commit 18734958e9bfbc055805d110a38dc76307eba742 upstream
Modify the intel_idle driver to get the C-states information from ACPI _CST if the processor model is not recognized by it.
The processor is still required to support MWAIT and the information from ACPI _CST will only be used if all of the C-states listed by _CST are of the ACPI_CSTATE_FFH type (which means that they are expected to be entered via MWAIT).
Moreover, the driver assumes that the _CST information is the same for all CPUs in the system, so it is sufficient to evaluate _CST for one of them and extract the common list of C-states from there. Also _CST is evaluated once at the system initialization time and the driver does not respond to _CST change notifications (that can be changed in the future).
The main functional difference between intel_idle with this change and the ACPI processor driver is that the former sets the target residency to be equal to the exit latency (provided by _CST) for C1-type C-states and to 3 times the exit latency value for the other C-state types, whereas the latter obtains the target residency by multiplying the exit latency by the same number (2 by default) for all C-state types. Therefore it is expected that in general using the former instead of the latter on the same system will lead to improved energy-efficiency.
Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: yjia yingbao.jia@intel.com Signed-off-by: Jackie Liu liuyun01@kylinos.cn Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Reviewed-by: Hanjun Guo guohanjun@huawei.com Reviewed-by: Xie XiuQi xiexiuqi@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- drivers/idle/intel_idle.c | 190 ++++++++++++++++++++++++++++++++------ 1 file changed, 162 insertions(+), 28 deletions(-)
diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c index 4bb1fc966c95..22fffcbebbf5 100644 --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -53,6 +53,7 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/acpi.h> #include <linux/kernel.h> #include <linux/cpuidle.h> #include <linux/tick.h> @@ -1125,6 +1126,129 @@ static const struct x86_cpu_id intel_idle_ids[] __initconst = { {} };
+#define INTEL_CPU_FAM6_MWAIT \ + { X86_VENDOR_INTEL, 6, X86_MODEL_ANY, X86_FEATURE_MWAIT, 0 } + +static const struct x86_cpu_id intel_mwait_ids[] __initconst = { + INTEL_CPU_FAM6_MWAIT, + {} +}; + +static bool intel_idle_max_cstate_reached(int cstate) +{ + if (cstate + 1 > max_cstate) { + pr_info("max_cstate %d reached\n", max_cstate); + return true; + } + return false; +} + +#ifdef CONFIG_ACPI_PROCESSOR_CSTATE +#include <acpi/processor.h> + +static struct acpi_processor_power acpi_state_table; + +/** + * intel_idle_cst_usable - Check if the _CST information can be used. + * + * Check if all of the C-states listed by _CST in the max_cstate range are + * ACPI_CSTATE_FFH, which means that they should be entered via MWAIT. + */ +static bool intel_idle_cst_usable(void) +{ + int cstate, limit; + + limit = min_t(int, min_t(int, CPUIDLE_STATE_MAX, max_cstate + 1), + acpi_state_table.count); + + for (cstate = 1; cstate < limit; cstate++) { + struct acpi_processor_cx *cx = &acpi_state_table.states[cstate]; + + if (cx->entry_method != ACPI_CSTATE_FFH) + return false; + } + + return true; +} + +static bool intel_idle_acpi_cst_extract(void) +{ + unsigned int cpu; + + for_each_possible_cpu(cpu) { + struct acpi_processor *pr = per_cpu(processors, cpu); + + if (!pr) + continue; + + if (acpi_processor_evaluate_cst(pr->handle, cpu, &acpi_state_table)) + continue; + + acpi_state_table.count++; + + if (!intel_idle_cst_usable()) + continue; + + if (!acpi_processor_claim_cst_control()) { + acpi_state_table.count = 0; + return false; + } + + return true; + } + + pr_debug("ACPI _CST not found or not usable\n"); + return false; +} + +static void intel_idle_init_cstates_acpi(struct cpuidle_driver *drv) +{ + int cstate, limit = min_t(int, CPUIDLE_STATE_MAX, acpi_state_table.count); + + /* + * If limit > 0, intel_idle_cst_usable() has returned 'true', so all of + * the interesting states are ACPI_CSTATE_FFH. + */ + for (cstate = 1; cstate < limit; cstate++) { + struct acpi_processor_cx *cx; + struct cpuidle_state *state; + + if (intel_idle_max_cstate_reached(cstate)) + break; + + cx = &acpi_state_table.states[cstate]; + + state = &drv->states[drv->state_count++]; + + snprintf(state->name, CPUIDLE_NAME_LEN, "C%d_ACPI", cstate); + strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN); + state->exit_latency = cx->latency; + /* + * For C1-type C-states use the same number for both the exit + * latency and target residency, because that is the case for + * C1 in the majority of the static C-states tables above. + * For the other types of C-states, however, set the target + * residency to 3 times the exit latency which should lead to + * a reasonable balance between energy-efficiency and + * performance in the majority of interesting cases. + */ + state->target_residency = cx->latency; + if (cx->type > ACPI_STATE_C1) + state->target_residency *= 3; + + state->flags = MWAIT2flg(cx->address); + if (cx->type > ACPI_STATE_C2) + state->flags |= CPUIDLE_FLAG_TLB_FLUSHED; + + state->enter = intel_idle; + state->enter_s2idle = intel_idle_s2idle; + } +} +#else /* !CONFIG_ACPI_PROCESSOR_CSTATE */ +static inline bool intel_idle_acpi_cst_extract(void) { return false; } +static inline void intel_idle_init_cstates_acpi(struct cpuidle_driver *drv) { } +#endif /* !CONFIG_ACPI_PROCESSOR_CSTATE */ + /* * intel_idle_probe() */ @@ -1139,17 +1263,15 @@ static int __init intel_idle_probe(void) }
id = x86_match_cpu(intel_idle_ids); - if (!id) { - if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL && - boot_cpu_data.x86 == 6) - pr_debug("does not run on family %d model %d\n", - boot_cpu_data.x86, boot_cpu_data.x86_model); - return -ENODEV; - } - - if (!boot_cpu_has(X86_FEATURE_MWAIT)) { - pr_debug("Please enable MWAIT in BIOS SETUP\n"); - return -ENODEV; + if (id) { + if (!boot_cpu_has(X86_FEATURE_MWAIT)) { + pr_debug("Please enable MWAIT in BIOS SETUP\n"); + return -ENODEV; + } + } else { + id = x86_match_cpu(intel_mwait_ids); + if (!id) + return -ENODEV; }
if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF) @@ -1165,7 +1287,10 @@ static int __init intel_idle_probe(void) pr_debug("MWAIT substates: 0x%x\n", mwait_substates);
icpu = (const struct idle_cpu *)id->driver_data; - cpuidle_state_table = icpu->state_table; + if (icpu) + cpuidle_state_table = icpu->state_table; + else if (!intel_idle_acpi_cst_extract()) + return -ENODEV;
pr_debug("v" INTEL_IDLE_VERSION " model 0x%X\n", boot_cpu_data.x86_model); @@ -1347,31 +1472,19 @@ static void intel_idle_state_table_update(void) } }
-/* - * intel_idle_cpuidle_driver_init() - * allocate, initialize cpuidle_states - */ -static void __init intel_idle_cpuidle_driver_init(void) +static void intel_idle_init_cstates_icpu(struct cpuidle_driver *drv) { int cstate; - struct cpuidle_driver *drv = &intel_idle_driver; - - intel_idle_state_table_update(); - - cpuidle_poll_state_init(drv); - drv->state_count = 1;
for (cstate = 0; cstate < CPUIDLE_STATE_MAX; ++cstate) { unsigned int mwait_hint;
- if (!cpuidle_state_table[cstate].enter && - !cpuidle_state_table[cstate].enter_s2idle) + if (intel_idle_max_cstate_reached(cstate)) break;
- if (cstate + 1 > max_cstate) { - pr_info("max_cstate %d reached\n", max_cstate); + if (!cpuidle_state_table[cstate].enter && + !cpuidle_state_table[cstate].enter_s2idle) break; - }
/* If marked as unusable, skip this state. */ if (cpuidle_state_table[cstate].disabled != 0) { @@ -1394,6 +1507,24 @@ static void __init intel_idle_cpuidle_driver_init(void) } }
+/* + * intel_idle_cpuidle_driver_init() + * allocate, initialize cpuidle_states + */ +static void __init intel_idle_cpuidle_driver_init(void) +{ + struct cpuidle_driver *drv = &intel_idle_driver; + + intel_idle_state_table_update(); + + cpuidle_poll_state_init(drv); + drv->state_count = 1; + + if (icpu) + intel_idle_init_cstates_icpu(drv); + else + intel_idle_init_cstates_acpi(drv); +}
/* * intel_idle_cpu_init() @@ -1412,6 +1543,9 @@ static int intel_idle_cpu_init(unsigned int cpu) return -EIO; }
+ if (!icpu) + return 0; + if (icpu->auto_demotion_disable_flags) auto_demotion_disable();