1 files changed, 117 insertions, 18 deletions

diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index 6c54a8f16706..f00fac363acd 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -95,6 +95,17 @@ static unsigned int pcc_mpar, pcc_mrtt, pcc_nominal;
                                 (cpc)->cpc_entry.reg.space_id ==        \
                                 ACPI_ADR_SPACE_PLATFORM_COMM)
 
+/* Evalutes to True if reg is a NULL register descriptor */
+#define IS_NULL_REG(reg) ((reg)->space_id ==  ACPI_ADR_SPACE_SYSTEM_MEMORY && \
+                                (reg)->address == 0 &&                  \
+                                (reg)->bit_width == 0 &&                \
+                                (reg)->bit_offset == 0 &&               \
+                                (reg)->access_width == 0)
+
+/* Evalutes to True if an optional cpc field is supported */
+#define CPC_SUPPORTED(cpc) ((cpc)->type == ACPI_TYPE_INTEGER ?          \
+                                !!(cpc)->cpc_entry.int_value :          \
+                                !IS_NULL_REG(&(cpc)->cpc_entry.reg))
 /*
  * Arbitrary Retries in case the remote processor is slow to respond
  * to PCC commands. Keeping it high enough to cover emulators where
@@ -102,6 +113,71 @@ static unsigned int pcc_mpar, pcc_mrtt, pcc_nominal;
  */
 #define NUM_RETRIES 500
 
+struct cppc_attr {
+        struct attribute attr;
+        ssize_t (*show)(struct kobject *kobj,
+                        struct attribute *attr, char *buf);
+        ssize_t (*store)(struct kobject *kobj,
+                        struct attribute *attr, const char *c, ssize_t count);
+};
+
+#define define_one_cppc_ro(_name)               \
+static struct cppc_attr _name =                 \
+__ATTR(_name, 0444, show_##_name, NULL)
+
+#define to_cpc_desc(a) container_of(a, struct cpc_desc, kobj)
+
+static ssize_t show_feedback_ctrs(struct kobject *kobj,
+                struct attribute *attr, char *buf)
+{
+        struct cpc_desc *cpc_ptr = to_cpc_desc(kobj);
+        struct cppc_perf_fb_ctrs fb_ctrs = {0};
+
+        cppc_get_perf_ctrs(cpc_ptr->cpu_id, &fb_ctrs);
+
+        return scnprintf(buf, PAGE_SIZE, "ref:%llu del:%llu\n",
+                        fb_ctrs.reference, fb_ctrs.delivered);
+}
+define_one_cppc_ro(feedback_ctrs);
+
+static ssize_t show_reference_perf(struct kobject *kobj,
+                struct attribute *attr, char *buf)
+{
+        struct cpc_desc *cpc_ptr = to_cpc_desc(kobj);
+        struct cppc_perf_fb_ctrs fb_ctrs = {0};
+
+        cppc_get_perf_ctrs(cpc_ptr->cpu_id, &fb_ctrs);
+
+        return scnprintf(buf, PAGE_SIZE, "%llu\n",
+                        fb_ctrs.reference_perf);
+}
+define_one_cppc_ro(reference_perf);
+
+static ssize_t show_wraparound_time(struct kobject *kobj,
+                                struct attribute *attr, char *buf)
+{
+        struct cpc_desc *cpc_ptr = to_cpc_desc(kobj);
+        struct cppc_perf_fb_ctrs fb_ctrs = {0};
+
+        cppc_get_perf_ctrs(cpc_ptr->cpu_id, &fb_ctrs);
+
+        return scnprintf(buf, PAGE_SIZE, "%llu\n", fb_ctrs.ctr_wrap_time);
+
+}
+define_one_cppc_ro(wraparound_time);
+
+static struct attribute *cppc_attrs[] = {
+        &feedback_ctrs.attr,
+        &reference_perf.attr,
+        &wraparound_time.attr,
+        NULL
+};
+
+static struct kobj_type cppc_ktype = {
+        .sysfs_ops = &kobj_sysfs_ops,
+        .default_attrs = cppc_attrs,
+};
+
 static int check_pcc_chan(void)
 {
         int ret = -EIO;
@@ -555,6 +631,7 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr)
         union acpi_object *out_obj, *cpc_obj;
         struct cpc_desc *cpc_ptr;
         struct cpc_reg *gas_t;
+        struct device *cpu_dev;
         acpi_handle handle = pr->handle;
         unsigned int num_ent, i, cpc_rev;
         acpi_status status;
@@ -678,6 +755,16 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr)
         /* Everything looks okay */
         pr_debug("Parsed CPC struct for CPU: %d\n", pr->id);
 
+        /* Add per logical CPU nodes for reading its feedback counters. */
+        cpu_dev = get_cpu_device(pr->id);
+        if (!cpu_dev)
+                goto out_free;
+
+        ret = kobject_init_and_add(&cpc_ptr->kobj, &cppc_ktype, &cpu_dev->kobj,
+                        "acpi_cppc");
+        if (ret)
+                goto out_free;
+
         kfree(output.pointer);
         return 0;
 
@@ -708,6 +795,7 @@ void acpi_cppc_processor_exit(struct acpi_processor *pr)
         struct cpc_desc *cpc_ptr;
         unsigned int i;
         void __iomem *addr;
+
         cpc_ptr = per_cpu(cpc_desc_ptr, pr->id);
 
         /* Free all the mapped sys mem areas for this CPU */
@@ -717,6 +805,7 @@ void acpi_cppc_processor_exit(struct acpi_processor *pr)
                         iounmap(addr);
         }
 
+        kobject_put(&cpc_ptr->kobj);
         kfree(cpc_ptr);
 }
 EXPORT_SYMBOL_GPL(acpi_cppc_processor_exit);
@@ -818,7 +907,7 @@ int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps)
         struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum);
         struct cpc_register_resource *highest_reg, *lowest_reg, *ref_perf,
                                                                  *nom_perf;
-        u64 high, low, ref, nom;
+        u64 high, low, nom;
         int ret = 0, regs_in_pcc = 0;
 
         if (!cpc_desc) {
@@ -849,15 +938,9 @@ int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps)
         cpc_read(lowest_reg, &low);
         perf_caps->lowest_perf = low;
 
-        cpc_read(ref_perf, &ref);
-        perf_caps->reference_perf = ref;
-
         cpc_read(nom_perf, &nom);
         perf_caps->nominal_perf = nom;
 
-        if (!ref)
-                perf_caps->reference_perf = perf_caps->nominal_perf;
-
         if (!high || !low || !nom)
                 ret = -EFAULT;
 
@@ -878,8 +961,9 @@ EXPORT_SYMBOL_GPL(cppc_get_perf_caps);
 int cppc_get_perf_ctrs(int cpunum, struct cppc_perf_fb_ctrs *perf_fb_ctrs)
 {
         struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum);
-        struct cpc_register_resource *delivered_reg, *reference_reg;
-        u64 delivered, reference;
+        struct cpc_register_resource *delivered_reg, *reference_reg,
+                *ref_perf_reg, *ctr_wrap_reg;
+        u64 delivered, reference, ref_perf, ctr_wrap_time;
         int ret = 0, regs_in_pcc = 0;
 
         if (!cpc_desc) {
@@ -889,9 +973,19 @@ int cppc_get_perf_ctrs(int cpunum, struct cppc_perf_fb_ctrs *perf_fb_ctrs)
 
         delivered_reg = &cpc_desc->cpc_regs[DELIVERED_CTR];
         reference_reg = &cpc_desc->cpc_regs[REFERENCE_CTR];
+        ref_perf_reg = &cpc_desc->cpc_regs[REFERENCE_PERF];
+        ctr_wrap_reg = &cpc_desc->cpc_regs[CTR_WRAP_TIME];
+
+        /*
+         * If refernce perf register is not supported then we should
+         * use the nominal perf value
+         */
+        if (!CPC_SUPPORTED(ref_perf_reg))
+                ref_perf_reg = &cpc_desc->cpc_regs[NOMINAL_PERF];
 
         /* Are any of the regs PCC ?*/
-        if (CPC_IN_PCC(delivered_reg) || CPC_IN_PCC(reference_reg)) {
+        if (CPC_IN_PCC(delivered_reg) || CPC_IN_PCC(reference_reg) ||
+                CPC_IN_PCC(ctr_wrap_reg) || CPC_IN_PCC(ref_perf_reg)) {
                 down_write(&pcc_lock);
                 regs_in_pcc = 1;
                 /* Ring doorbell once to update PCC subspace */
@@ -903,21 +997,26 @@ int cppc_get_perf_ctrs(int cpunum, struct cppc_perf_fb_ctrs *perf_fb_ctrs)
 
         cpc_read(delivered_reg, &delivered);
         cpc_read(reference_reg, &reference);
+        cpc_read(ref_perf_reg, &ref_perf);
+
+        /*
+         * Per spec, if ctr_wrap_time optional register is unsupported, then the
+         * performance counters are assumed to never wrap during the lifetime of
+         * platform
+         */
+        ctr_wrap_time = (u64)(~((u64)0));
+        if (CPC_SUPPORTED(ctr_wrap_reg))
+                cpc_read(ctr_wrap_reg, &ctr_wrap_time);
 
-        if (!delivered || !reference) {
+        if (!delivered || !reference || !ref_perf) {
                 ret = -EFAULT;
                 goto out_err;
         }
 
         perf_fb_ctrs->delivered = delivered;
         perf_fb_ctrs->reference = reference;
-
-        perf_fb_ctrs->delivered -= perf_fb_ctrs->prev_delivered;
-        perf_fb_ctrs->reference -= perf_fb_ctrs->prev_reference;
-
-        perf_fb_ctrs->prev_delivered = delivered;
-        perf_fb_ctrs->prev_reference = reference;
-
+        perf_fb_ctrs->reference_perf = ref_perf;
+        perf_fb_ctrs->ctr_wrap_time = ctr_wrap_time;
 out_err:
         if (regs_in_pcc)
                 up_write(&pcc_lock);