powerpc/powernv: Add support for powercap framework
authorShilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Thu, 10 Aug 2017 03:31:18 +0000 (09:01 +0530)
committerMichael Ellerman <mpe@ellerman.id.au>
Thu, 10 Aug 2017 12:39:53 +0000 (22:39 +1000)
Adds a generic powercap framework to change the system powercap
inband through OPAL-OCC command/response interface.

Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Documentation/ABI/testing/sysfs-firmware-opal-powercap [new file with mode: 0644]
arch/powerpc/include/asm/opal-api.h
arch/powerpc/include/asm/opal.h
arch/powerpc/platforms/powernv/Makefile
arch/powerpc/platforms/powernv/opal-powercap.c [new file with mode: 0644]
arch/powerpc/platforms/powernv/opal-wrappers.S
arch/powerpc/platforms/powernv/opal.c

diff --git a/Documentation/ABI/testing/sysfs-firmware-opal-powercap b/Documentation/ABI/testing/sysfs-firmware-opal-powercap
new file mode 100644 (file)
index 0000000..c9b66ec
--- /dev/null
@@ -0,0 +1,31 @@
+What:          /sys/firmware/opal/powercap
+Date:          August 2017
+Contact:       Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org>
+Description:   Powercap directory for Powernv (P8, P9) servers
+
+               Each folder in this directory contains a
+               power-cappable component.
+
+What:          /sys/firmware/opal/powercap/system-powercap
+               /sys/firmware/opal/powercap/system-powercap/powercap-min
+               /sys/firmware/opal/powercap/system-powercap/powercap-max
+               /sys/firmware/opal/powercap/system-powercap/powercap-current
+Date:          August 2017
+Contact:       Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org>
+Description:   System powercap directory and attributes applicable for
+               Powernv (P8, P9) servers
+
+               This directory provides powercap information. It
+               contains below sysfs attributes:
+
+               - powercap-min : This file provides the minimum
+                 possible powercap in Watt units
+
+               - powercap-max : This file provides the maximum
+                 possible powercap in Watt units
+
+               - powercap-current : This file provides the current
+                 powercap set on the system. Writing to this file
+                 creates a request for setting a new-powercap. The
+                 powercap requested must be between powercap-min
+                 and powercap-max.
index ced1ef21e981b9cd3d8ac895c572a29e0756dfeb..b87305b22746b77a0e9a37a946adad935237f3e1 100644 (file)
@@ -42,6 +42,7 @@
 #define OPAL_I2C_STOP_ERR      -24
 #define OPAL_XIVE_PROVISIONING -31
 #define OPAL_XIVE_FREE_ACTIVE  -32
+#define OPAL_TIMEOUT           -33
 
 /* API Tokens (in r0) */
 #define OPAL_INVALID_CALL                     -1
 #define OPAL_IMC_COUNTERS_INIT                 149
 #define OPAL_IMC_COUNTERS_START                        150
 #define OPAL_IMC_COUNTERS_STOP                 151
+#define OPAL_GET_POWERCAP                      152
+#define OPAL_SET_POWERCAP                      153
 #define OPAL_PCI_SET_P2P                       157
 #define OPAL_LAST                              157
 
index 5a715e66f910a17811f43569f898c4b9187a9e22..6f09ab74aa7b5f4c6147e766580243ff0b93df7c 100644 (file)
@@ -275,6 +275,9 @@ int64_t opal_imc_counters_init(uint32_t type, uint64_t address,
 int64_t opal_imc_counters_start(uint32_t type, uint64_t cpu_pir);
 int64_t opal_imc_counters_stop(uint32_t type, uint64_t cpu_pir);
 
+int opal_get_powercap(u32 handle, int token, u32 *pcap);
+int opal_set_powercap(u32 handle, int token, u32 pcap);
+
 /* Internal functions */
 extern int early_init_dt_scan_opal(unsigned long node, const char *uname,
                                   int depth, void *data);
@@ -352,6 +355,8 @@ static inline int opal_get_async_rc(struct opal_msg msg)
 
 void opal_wake_poller(void);
 
+void opal_powercap_init(void);
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* _ASM_POWERPC_OPAL_H */
index a0d4353a17c9f97e39b66ad4c71e1e5def411624..f9ec36d0e6845747d37ec4a158d43834a4f562f5 100644 (file)
@@ -2,7 +2,7 @@ obj-y                   += setup.o opal-wrappers.o opal.o opal-async.o idle.o
 obj-y                  += opal-rtc.o opal-nvram.o opal-lpc.o opal-flash.o
 obj-y                  += rng.o opal-elog.o opal-dump.o opal-sysparam.o opal-sensor.o
 obj-y                  += opal-msglog.o opal-hmi.o opal-power.o opal-irqchip.o
-obj-y                  += opal-kmsg.o
+obj-y                  += opal-kmsg.o opal-powercap.o
 
 obj-$(CONFIG_SMP)      += smp.o subcore.o subcore-asm.o
 obj-$(CONFIG_PCI)      += pci.o pci-ioda.o npu-dma.o
diff --git a/arch/powerpc/platforms/powernv/opal-powercap.c b/arch/powerpc/platforms/powernv/opal-powercap.c
new file mode 100644 (file)
index 0000000..badb29b
--- /dev/null
@@ -0,0 +1,244 @@
+/*
+ * PowerNV OPAL Powercap interface
+ *
+ * Copyright 2017 IBM Corp.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#define pr_fmt(fmt)     "opal-powercap: " fmt
+
+#include <linux/of.h>
+#include <linux/kobject.h>
+#include <linux/slab.h>
+
+#include <asm/opal.h>
+
+DEFINE_MUTEX(powercap_mutex);
+
+static struct kobject *powercap_kobj;
+
+struct powercap_attr {
+       u32 handle;
+       struct kobj_attribute attr;
+};
+
+static struct pcap {
+       struct attribute_group pg;
+       struct powercap_attr *pattrs;
+} *pcaps;
+
+static ssize_t powercap_show(struct kobject *kobj, struct kobj_attribute *attr,
+                            char *buf)
+{
+       struct powercap_attr *pcap_attr = container_of(attr,
+                                               struct powercap_attr, attr);
+       struct opal_msg msg;
+       u32 pcap;
+       int ret, token;
+
+       token = opal_async_get_token_interruptible();
+       if (token < 0) {
+               pr_devel("Failed to get token\n");
+               return token;
+       }
+
+       ret = mutex_lock_interruptible(&powercap_mutex);
+       if (ret)
+               goto out_token;
+
+       ret = opal_get_powercap(pcap_attr->handle, token, (u32 *)__pa(&pcap));
+       switch (ret) {
+       case OPAL_ASYNC_COMPLETION:
+               ret = opal_async_wait_response(token, &msg);
+               if (ret) {
+                       pr_devel("Failed to wait for the async response\n");
+                       ret = -EIO;
+                       goto out;
+               }
+               ret = opal_error_code(opal_get_async_rc(msg));
+               if (!ret) {
+                       ret = sprintf(buf, "%u\n", be32_to_cpu(pcap));
+                       if (ret < 0)
+                               ret = -EIO;
+               }
+               break;
+       case OPAL_SUCCESS:
+               ret = sprintf(buf, "%u\n", be32_to_cpu(pcap));
+               if (ret < 0)
+                       ret = -EIO;
+               break;
+       default:
+               ret = opal_error_code(ret);
+       }
+
+out:
+       mutex_unlock(&powercap_mutex);
+out_token:
+       opal_async_release_token(token);
+       return ret;
+}
+
+static ssize_t powercap_store(struct kobject *kobj,
+                             struct kobj_attribute *attr, const char *buf,
+                             size_t count)
+{
+       struct powercap_attr *pcap_attr = container_of(attr,
+                                               struct powercap_attr, attr);
+       struct opal_msg msg;
+       u32 pcap;
+       int ret, token;
+
+       ret = kstrtoint(buf, 0, &pcap);
+       if (ret)
+               return ret;
+
+       token = opal_async_get_token_interruptible();
+       if (token < 0) {
+               pr_devel("Failed to get token\n");
+               return token;
+       }
+
+       ret = mutex_lock_interruptible(&powercap_mutex);
+       if (ret)
+               goto out_token;
+
+       ret = opal_set_powercap(pcap_attr->handle, token, pcap);
+       switch (ret) {
+       case OPAL_ASYNC_COMPLETION:
+               ret = opal_async_wait_response(token, &msg);
+               if (ret) {
+                       pr_devel("Failed to wait for the async response\n");
+                       ret = -EIO;
+                       goto out;
+               }
+               ret = opal_error_code(opal_get_async_rc(msg));
+               if (!ret)
+                       ret = count;
+               break;
+       case OPAL_SUCCESS:
+               ret = count;
+               break;
+       default:
+               ret = opal_error_code(ret);
+       }
+
+out:
+       mutex_unlock(&powercap_mutex);
+out_token:
+       opal_async_release_token(token);
+       return ret;
+}
+
+static void powercap_add_attr(int handle, const char *name,
+                             struct powercap_attr *attr)
+{
+       attr->handle = handle;
+       sysfs_attr_init(&attr->attr.attr);
+       attr->attr.attr.name = name;
+       attr->attr.attr.mode = 0444;
+       attr->attr.show = powercap_show;
+}
+
+void __init opal_powercap_init(void)
+{
+       struct device_node *powercap, *node;
+       int i = 0;
+
+       powercap = of_find_compatible_node(NULL, NULL, "ibm,opal-powercap");
+       if (!powercap) {
+               pr_devel("Powercap node not found\n");
+               return;
+       }
+
+       pcaps = kcalloc(of_get_child_count(powercap), sizeof(*pcaps),
+                       GFP_KERNEL);
+       if (!pcaps)
+               return;
+
+       powercap_kobj = kobject_create_and_add("powercap", opal_kobj);
+       if (!powercap_kobj) {
+               pr_warn("Failed to create powercap kobject\n");
+               goto out_pcaps;
+       }
+
+       i = 0;
+       for_each_child_of_node(powercap, node) {
+               u32 cur, min, max;
+               int j = 0;
+               bool has_cur = false, has_min = false, has_max = false;
+
+               if (!of_property_read_u32(node, "powercap-min", &min)) {
+                       j++;
+                       has_min = true;
+               }
+
+               if (!of_property_read_u32(node, "powercap-max", &max)) {
+                       j++;
+                       has_max = true;
+               }
+
+               if (!of_property_read_u32(node, "powercap-current", &cur)) {
+                       j++;
+                       has_cur = true;
+               }
+
+               pcaps[i].pattrs = kcalloc(j, sizeof(struct powercap_attr),
+                                         GFP_KERNEL);
+               if (!pcaps[i].pattrs)
+                       goto out_pcaps_pattrs;
+
+               pcaps[i].pg.attrs = kcalloc(j + 1, sizeof(struct attribute *),
+                                           GFP_KERNEL);
+               if (!pcaps[i].pg.attrs) {
+                       kfree(pcaps[i].pattrs);
+                       goto out_pcaps_pattrs;
+               }
+
+               j = 0;
+               pcaps[i].pg.name = node->name;
+               if (has_min) {
+                       powercap_add_attr(min, "powercap-min",
+                                         &pcaps[i].pattrs[j]);
+                       pcaps[i].pg.attrs[j] = &pcaps[i].pattrs[j].attr.attr;
+                       j++;
+               }
+
+               if (has_max) {
+                       powercap_add_attr(max, "powercap-max",
+                                         &pcaps[i].pattrs[j]);
+                       pcaps[i].pg.attrs[j] = &pcaps[i].pattrs[j].attr.attr;
+                       j++;
+               }
+
+               if (has_cur) {
+                       powercap_add_attr(cur, "powercap-current",
+                                         &pcaps[i].pattrs[j]);
+                       pcaps[i].pattrs[j].attr.attr.mode |= 0220;
+                       pcaps[i].pattrs[j].attr.store = powercap_store;
+                       pcaps[i].pg.attrs[j] = &pcaps[i].pattrs[j].attr.attr;
+                       j++;
+               }
+
+               if (sysfs_create_group(powercap_kobj, &pcaps[i].pg)) {
+                       pr_warn("Failed to create powercap attribute group %s\n",
+                               pcaps[i].pg.name);
+                       goto out_pcaps_pattrs;
+               }
+               i++;
+       }
+
+       return;
+
+out_pcaps_pattrs:
+       while (--i >= 0) {
+               kfree(pcaps[i].pattrs);
+               kfree(pcaps[i].pg.attrs);
+       }
+       kobject_put(powercap_kobj);
+out_pcaps:
+       kfree(pcaps);
+}
index 3369a6f2b2f1a7ad8c1fed6d24378942599445e8..139286c9880838bed77afafb5ea2dc1499332b23 100644 (file)
@@ -314,3 +314,5 @@ OPAL_CALL(opal_imc_counters_init,           OPAL_IMC_COUNTERS_INIT);
 OPAL_CALL(opal_imc_counters_start,             OPAL_IMC_COUNTERS_START);
 OPAL_CALL(opal_imc_counters_stop,              OPAL_IMC_COUNTERS_STOP);
 OPAL_CALL(opal_pci_set_p2p,                    OPAL_PCI_SET_P2P);
+OPAL_CALL(opal_get_powercap,                   OPAL_GET_POWERCAP);
+OPAL_CALL(opal_set_powercap,                   OPAL_SET_POWERCAP);
index 946158e6fc1dd033e661e6a573318dfe08708b73..28323c75e672fec59e64703bff1d03b44f9698d4 100644 (file)
@@ -850,6 +850,9 @@ static int __init opal_init(void)
        /* Initialise OPAL kmsg dumper for flushing console on panic */
        opal_kmsg_init();
 
+       /* Initialise OPAL powercap interface */
+       opal_powercap_init();
+
        return 0;
 }
 machine_subsys_initcall(powernv, opal_init);
@@ -966,6 +969,7 @@ int opal_error_code(int rc)
        case OPAL_UNSUPPORTED:          return -EIO;
        case OPAL_HARDWARE:             return -EIO;
        case OPAL_INTERNAL_ERROR:       return -EIO;
+       case OPAL_TIMEOUT:              return -ETIMEDOUT;
        default:
                pr_err("%s: unexpected OPAL error %d\n", __func__, rc);
                return -EIO;