hwmon: (fam15h_power) Add compute unit accumulated power

This patch adds a member in fam15h_power_data which specifies the
compute unit accumulated power. It adds do_read_registers_on_cu to do
all the read to all MSRs and run it on one of the online cores on each
compute unit with smp_call_function_many(). This behavior can decrease
IPI numbers.

Suggested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/drivers/hwmon/fam15h_power.c b/drivers/hwmon/fam15h_power.c
index 4f695d8fcafaceab3c5d8caaa677b58e94ae9c2c..4edbaf0831308c7ff0840bd38728342ab32ed24c 100644 (file)
--- a/drivers/hwmon/fam15h_power.c
+++ b/drivers/hwmon/fam15h_power.c
@@ -25,6 +25,8 @@
 #include <linux/module.h>
 #include <linux/pci.h>
 #include <linux/bitops.h>
+#include <linux/cpu.h>
+#include <linux/cpumask.h>
 #include <asm/processor.h>
 #include <asm/msr.h>
 
@@ -44,7 +46,9 @@ MODULE_LICENSE("GPL");
 
 #define FAM15H_MIN_NUM_ATTRS           2
 #define FAM15H_NUM_GROUPS              2
+#define MAX_CUS                                8
 
+#define MSR_F15H_CU_PWR_ACCUMULATOR    0xc001007a
 #define MSR_F15H_CU_MAX_PWR_ACCUMULATOR        0xc001007b
 
 #define PCI_DEVICE_ID_AMD_15H_M70H_NB_F4 0x15b4
@@ -59,6 +63,8 @@ struct fam15h_power_data {
        struct attribute_group group;
        /* maximum accumulated power of a compute unit */
        u64 max_cu_acc_power;
+       /* accumulated power of the compute units */
+       u64 cu_acc_power[MAX_CUS];
 };
 
 static ssize_t show_power(struct device *dev,
@@ -125,6 +131,70 @@ static ssize_t show_power_crit(struct device *dev,
 }
 static DEVICE_ATTR(power1_crit, S_IRUGO, show_power_crit, NULL);
 
+static void do_read_registers_on_cu(void *_data)
+{
+       struct fam15h_power_data *data = _data;
+       int cpu, cu;
+
+       cpu = smp_processor_id();
+
+       /*
+        * With the new x86 topology modelling, cpu core id actually
+        * is compute unit id.
+        */
+       cu = cpu_data(cpu).cpu_core_id;
+
+       rdmsrl_safe(MSR_F15H_CU_PWR_ACCUMULATOR, &data->cu_acc_power[cu]);
+}
+
+/*
+ * This function is only able to be called when CPUID
+ * Fn8000_0007:EDX[12] is set.
+ */
+static int read_registers(struct fam15h_power_data *data)
+{
+       int this_cpu, ret, cpu;
+       int core, this_core;
+       cpumask_var_t mask;
+
+       ret = zalloc_cpumask_var(&mask, GFP_KERNEL);
+       if (!ret)
+               return -ENOMEM;
+
+       get_online_cpus();
+       this_cpu = smp_processor_id();
+
+       /*
+        * Choose the first online core of each compute unit, and then
+        * read their MSR value of power and ptsc in a single IPI,
+        * because the MSR value of CPU core represent the compute
+        * unit's.
+        */
+       core = -1;
+
+       for_each_online_cpu(cpu) {
+               this_core = topology_core_id(cpu);
+
+               if (this_core == core)
+                       continue;
+
+               core = this_core;
+
+               /* get any CPU on this compute unit */
+               cpumask_set_cpu(cpumask_any(topology_sibling_cpumask(cpu)), mask);
+       }
+
+       if (cpumask_test_cpu(this_cpu, mask))
+               do_read_registers_on_cu(data);
+
+       smp_call_function_many(mask, do_read_registers_on_cu, data, true);
+       put_online_cpus();
+
+       free_cpumask_var(mask);
+
+       return 0;
+}
+
 static int fam15h_power_init_attrs(struct pci_dev *pdev,
                                   struct fam15h_power_data *data)
 {
@@ -263,7 +333,7 @@ static int fam15h_power_init_data(struct pci_dev *f4,
 
        data->max_cu_acc_power = tmp;
 
-       return 0;
+       return read_registers(data);
 }
 
 static int fam15h_power_probe(struct pci_dev *pdev,