P-state software coordination for ACPI core

http://bugzilla.kernel.org/show_bug.cgi?id=5737

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

3 files changed, 258 insertions, 1 deletions

diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c
index abbdb37a7f5f..ffc5280334c8 100644
--- a/drivers/acpi/processor_perflib.c
+++ b/drivers/acpi/processor_perflib.c
@@ -553,6 +553,234 @@ static void acpi_cpufreq_remove_file(struct acpi_processor *pr)
 }
 #endif                          /* CONFIG_X86_ACPI_CPUFREQ_PROC_INTF */
 
+static int acpi_processor_get_psd(struct acpi_processor *pr)
+{
+        int result = 0;
+        acpi_status status = AE_OK;
+        struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
+        struct acpi_buffer format = {sizeof("NNNNN"), "NNNNN"};
+        struct acpi_buffer state = {0, NULL};
+        union acpi_object  *psd = NULL;
+        struct acpi_psd_package *pdomain;
+
+        ACPI_FUNCTION_TRACE("acpi_processor_get_psd");
+
+        status = acpi_evaluate_object(pr->handle, "_PSD", NULL, &buffer);
+        if (ACPI_FAILURE(status)) {
+                return_VALUE(-ENODEV);
+        }
+
+        psd = (union acpi_object *) buffer.pointer;
+        if (!psd || (psd->type != ACPI_TYPE_PACKAGE)) {
+                ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _PSD data\n"));
+                result = -EFAULT;
+                goto end;
+        }
+
+        if (psd->package.count != 1) {
+                ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _PSD data\n"));
+                result = -EFAULT;
+                goto end;
+        }
+
+        pdomain = &(pr->performance->domain_info);
+
+        state.length = sizeof(struct acpi_psd_package);
+        state.pointer = pdomain;
+
+        status = acpi_extract_package(&(psd->package.elements[0]),
+                &format, &state);
+        if (ACPI_FAILURE(status)) {
+                ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _PSD data\n"));
+                result = -EFAULT;
+                goto end;
+        }
+
+        if (pdomain->num_entries != ACPI_PSD_REV0_ENTRIES) {
+                ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unknown _PSD:num_entries\n"));
+                result = -EFAULT;
+                goto end;
+        }
+
+        if (pdomain->revision != ACPI_PSD_REV0_REVISION) {
+                ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unknown _PSD:revision\n"));
+                result = -EFAULT;
+                goto end;
+        }
+
+end:
+        acpi_os_free(buffer.pointer);
+        return_VALUE(result);
+}
+
+int acpi_processor_preregister_performance(
+                struct acpi_processor_performance **performance)
+{
+        int count, count_target;
+        int retval = 0;
+        unsigned int i, j;
+        cpumask_t covered_cpus;
+        struct acpi_processor *pr;
+        struct acpi_psd_package *pdomain;
+        struct acpi_processor *match_pr;
+        struct acpi_psd_package *match_pdomain;
+
+        ACPI_FUNCTION_TRACE("acpi_processor_preregister_performance");
+
+        down(&performance_sem);
+
+        retval = 0;
+
+        /* Call _PSD for all CPUs */
+        for_each_cpu(i) {
+                pr = processors[i];
+                if (!pr) {
+                        /* Look only at processors in ACPI namespace */
+                        continue;
+                }
+
+                if (pr->performance) {
+                        retval = -EBUSY;
+                        continue;
+                }
+
+                if (!performance || !performance[i]) {
+                        retval = -EINVAL;
+                        continue;
+                }
+
+                pr->performance = performance[i];
+                cpu_set(i, pr->performance->shared_cpu_map);
+                if (acpi_processor_get_psd(pr)) {
+                        retval = -EINVAL;
+                        continue;
+                }
+        }
+        if (retval)
+                goto err_ret;
+
+        /*
+         * Now that we have _PSD data from all CPUs, lets setup P-state 
+         * domain info.
+         */
+        for_each_cpu(i) {
+                pr = processors[i];
+                if (!pr)
+                        continue;
+
+                /* Basic validity check for domain info */
+                pdomain = &(pr->performance->domain_info);
+                if ((pdomain->revision != ACPI_PSD_REV0_REVISION) ||
+                    (pdomain->num_entries != ACPI_PSD_REV0_ENTRIES)) {
+                        retval = -EINVAL;
+                        goto err_ret;
+                }
+                if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL &&
+                    pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY &&
+                    pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) {
+                        retval = -EINVAL;
+                        goto err_ret;
+                }
+        }
+
+        cpus_clear(covered_cpus);
+        for_each_cpu(i) {
+                pr = processors[i];
+                if (!pr)
+                        continue;
+
+                if (cpu_isset(i, covered_cpus))
+                        continue;
+
+                pdomain = &(pr->performance->domain_info);
+                cpu_set(i, pr->performance->shared_cpu_map);
+                cpu_set(i, covered_cpus);
+                if (pdomain->num_processors <= 1)
+                        continue;
+
+                /* Validate the Domain info */
+                count_target = pdomain->num_processors;
+                count = 1;
+                if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ALL ||
+                    pdomain->coord_type == DOMAIN_COORD_TYPE_HW_ALL) {
+                        pr->performance->shared_type = CPUFREQ_SHARED_TYPE_ALL;
+                } else if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ANY) {
+                        pr->performance->shared_type = CPUFREQ_SHARED_TYPE_ANY;
+                }
+
+                for_each_cpu(j) {
+                        if (i == j)
+                                continue;
+
+                        match_pr = processors[j];
+                        if (!match_pr)
+                                continue;
+
+                        match_pdomain = &(match_pr->performance->domain_info);
+                        if (match_pdomain->domain != pdomain->domain)
+                                continue;
+
+                        /* Here i and j are in the same domain */
+
+                        if (match_pdomain->num_processors != count_target) {
+                                retval = -EINVAL;
+                                goto err_ret;
+                        }
+
+                        if (pdomain->coord_type != match_pdomain->coord_type) {
+                                retval = -EINVAL;
+                                goto err_ret;
+                        }
+
+                        cpu_set(j, covered_cpus);
+                        cpu_set(j, pr->performance->shared_cpu_map);
+                        count++;
+                }
+
+                for_each_cpu(j) {
+                        if (i == j)
+                                continue;
+
+                        match_pr = processors[j];
+                        if (!match_pr)
+                                continue;
+
+                        match_pdomain = &(match_pr->performance->domain_info);
+                        if (match_pdomain->domain != pdomain->domain)
+                                continue;
+
+                        match_pr->performance->shared_type = 
+                                        pr->performance->shared_type;
+                        match_pr->performance->shared_cpu_map =
+                                pr->performance->shared_cpu_map;
+                }
+        }
+
+err_ret:
+        if (retval) {
+                ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error while parsing _PSD domain information. Assuming no coordination\n"));
+        }
+
+        for_each_cpu(i) {
+                pr = processors[i];
+                if (!pr || !pr->performance)
+                        continue;
+
+                /* Assume no coordination on any error parsing domain info */
+                if (retval) {
+                        cpus_clear(pr->performance->shared_cpu_map);
+                        cpu_set(i, pr->performance->shared_cpu_map);
+                        pr->performance->shared_type = CPUFREQ_SHARED_TYPE_ALL;
+                }
+                pr->performance = NULL; /* Will be set for real in register */
+        }
+
+        up(&performance_sem);
+        return_VALUE(retval);
+}
+EXPORT_SYMBOL(acpi_processor_preregister_performance);
+
+
 int
 acpi_processor_register_performance(struct acpi_processor_performance
                                     *performance, unsigned int cpu)
diff --git a/include/acpi/processor.h b/include/acpi/processor.h
index badf0277b1be..0c46d1b3dda2 100644
--- a/include/acpi/processor.h
+++ b/include/acpi/processor.h
@@ -3,6 +3,7 @@
 
 #include <linux/kernel.h>
 #include <linux/config.h>
+#include <linux/cpu.h>
 
 #include <asm/acpi.h>
 
@@ -18,6 +19,17 @@
 
 #define ACPI_PDC_REVISION_ID            0x1
 
+#define ACPI_PSD_REV0_REVISION          0 /* Support for _PSD as in ACPI 3.0 */
+#define ACPI_PSD_REV0_ENTRIES           5
+
+/*
+ * Types of coordination defined in ACPI 3.0. Same macros can be used across
+ * P, C and T states
+ */
+#define DOMAIN_COORD_TYPE_SW_ALL        0xfc
+#define DOMAIN_COORD_TYPE_SW_ANY        0xfd
+#define DOMAIN_COORD_TYPE_HW_ALL        0xfe
+
 /* Power Management */
 
 struct acpi_processor_cx;
@@ -66,6 +78,14 @@ struct acpi_processor_power {
 
 /* Performance Management */
 
+struct acpi_psd_package {
+        acpi_integer num_entries;
+        acpi_integer revision;
+        acpi_integer domain;
+        acpi_integer coord_type;
+        acpi_integer num_processors;
+} __attribute__ ((packed));
+
 struct acpi_pct_register {
         u8 descriptor;
         u16 length;
@@ -92,7 +112,9 @@ struct acpi_processor_performance {
         struct acpi_pct_register status_register;
         unsigned int state_count;
         struct acpi_processor_px *states;
-
+        struct acpi_psd_package domain_info;
+        cpumask_t shared_cpu_map;
+        unsigned int shared_type;
 };
 
 /* Throttling Control */
@@ -161,6 +183,9 @@ struct acpi_processor_errata {
         } piix4;
 };
 
+extern int acpi_processor_preregister_performance(
+                struct acpi_processor_performance **performance);
+
 extern int acpi_processor_register_performance(struct acpi_processor_performance
                                                *performance, unsigned int cpu);
 extern void acpi_processor_unregister_performance(struct
diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index 17866d7e2b71..f7d988366941 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -73,6 +73,8 @@ struct cpufreq_real_policy {
 
 struct cpufreq_policy {
         cpumask_t               cpus;   /* affected CPUs */
+        unsigned int            shared_type; /* ANY or ALL affected CPUs
+                                                should set cpufreq */
         unsigned int            cpu;    /* cpu nr of registered CPU */
         struct cpufreq_cpuinfo  cpuinfo;/* see above */
 
@@ -99,6 +101,8 @@ struct cpufreq_policy {
 #define CPUFREQ_INCOMPATIBLE    (1)
 #define CPUFREQ_NOTIFY          (2)
 
+#define CPUFREQ_SHARED_TYPE_ALL (0) /* All dependent CPUs should set freq */
+#define CPUFREQ_SHARED_TYPE_ANY (1) /* Freq can be set from any dependent CPU */
 
 /******************** cpufreq transition notifiers *******************/