powerpc/powernv: Add support to set power-shifting-ratio
authorShilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Thu, 10 Aug 2017 03:31:19 +0000 (09:01 +0530)
committerMichael Ellerman <mpe@ellerman.id.au>
Thu, 10 Aug 2017 12:40:01 +0000 (22:40 +1000)
This patch adds support to set power-shifting-ratio which hints the
firmware how to distribute/throttle power between different entities
in a system (e.g CPU v/s GPU). This ratio is used by OCC for power
capping algorithm.

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-psr [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-psr.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-psr b/Documentation/ABI/testing/sysfs-firmware-opal-psr
new file mode 100644 (file)
index 0000000..cc2ece7
--- /dev/null
@@ -0,0 +1,18 @@
+What:          /sys/firmware/opal/psr
+Date:          August 2017
+Contact:       Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org>
+Description:   Power-Shift-Ratio directory for Powernv P9 servers
+
+               Power-Shift-Ratio allows to provide hints the firmware
+               to shift/throttle power between different entities in
+               the system. Each attribute in this directory indicates
+               a settable PSR.
+
+What:          /sys/firmware/opal/psr/cpu_to_gpu_X
+Date:          August 2017
+Contact:       Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org>
+Description:   PSR sysfs attributes for Powernv P9 servers
+
+               Power-Shift-Ratio between CPU and GPU for a given chip
+               with chip-id X. This file gives the ratio (0-100)
+               which is used by OCC for power-capping.
index b87305b22746b77a0e9a37a946adad935237f3e1..0cb7d110c0b44e800d6901d2c481a61a5d51eb88 100644 (file)
 #define OPAL_IMC_COUNTERS_STOP                 151
 #define OPAL_GET_POWERCAP                      152
 #define OPAL_SET_POWERCAP                      153
+#define OPAL_GET_POWER_SHIFT_RATIO             154
+#define OPAL_SET_POWER_SHIFT_RATIO             155
 #define OPAL_PCI_SET_P2P                       157
 #define OPAL_LAST                              157
 
index 6f09ab74aa7b5f4c6147e766580243ff0b93df7c..d87ffcb16b6119a9c5e48e8675a623755198ed8f 100644 (file)
@@ -277,6 +277,8 @@ 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);
+int opal_get_power_shift_ratio(u32 handle, int token, u32 *psr);
+int opal_set_power_shift_ratio(u32 handle, int token, u32 psr);
 
 /* Internal functions */
 extern int early_init_dt_scan_opal(unsigned long node, const char *uname,
@@ -356,6 +358,7 @@ static inline int opal_get_async_rc(struct opal_msg msg)
 void opal_wake_poller(void);
 
 void opal_powercap_init(void);
+void opal_psr_init(void);
 
 #endif /* __ASSEMBLY__ */
 
index f9ec36d0e6845747d37ec4a158d43834a4f562f5..674ed1e8160aacd7d7184e5434131b198173d2ae 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 opal-powercap.o
+obj-y                  += opal-kmsg.o opal-powercap.o opal-psr.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-psr.c b/arch/powerpc/platforms/powernv/opal-psr.c
new file mode 100644 (file)
index 0000000..7313b7f
--- /dev/null
@@ -0,0 +1,175 @@
+/*
+ * PowerNV OPAL Power-Shift-Ratio 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-psr: " fmt
+
+#include <linux/of.h>
+#include <linux/kobject.h>
+#include <linux/slab.h>
+
+#include <asm/opal.h>
+
+DEFINE_MUTEX(psr_mutex);
+
+static struct kobject *psr_kobj;
+
+struct psr_attr {
+       u32 handle;
+       struct kobj_attribute attr;
+} *psr_attrs;
+
+static ssize_t psr_show(struct kobject *kobj, struct kobj_attribute *attr,
+                       char *buf)
+{
+       struct psr_attr *psr_attr = container_of(attr, struct psr_attr, attr);
+       struct opal_msg msg;
+       int psr, ret, token;
+
+       token = opal_async_get_token_interruptible();
+       if (token < 0) {
+               pr_devel("Failed to get token\n");
+               return token;
+       }
+
+       ret = mutex_lock_interruptible(&psr_mutex);
+       if (ret)
+               goto out_token;
+
+       ret = opal_get_power_shift_ratio(psr_attr->handle, token,
+                                           (u32 *)__pa(&psr));
+       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(psr));
+                       if (ret < 0)
+                               ret = -EIO;
+               }
+               break;
+       case OPAL_SUCCESS:
+               ret = sprintf(buf, "%u\n", be32_to_cpu(psr));
+               if (ret < 0)
+                       ret = -EIO;
+               break;
+       default:
+               ret = opal_error_code(ret);
+       }
+
+out:
+       mutex_unlock(&psr_mutex);
+out_token:
+       opal_async_release_token(token);
+       return ret;
+}
+
+static ssize_t psr_store(struct kobject *kobj, struct kobj_attribute *attr,
+                        const char *buf, size_t count)
+{
+       struct psr_attr *psr_attr = container_of(attr, struct psr_attr, attr);
+       struct opal_msg msg;
+       int psr, ret, token;
+
+       ret = kstrtoint(buf, 0, &psr);
+       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(&psr_mutex);
+       if (ret)
+               goto out_token;
+
+       ret = opal_set_power_shift_ratio(psr_attr->handle, token, psr);
+       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(&psr_mutex);
+out_token:
+       opal_async_release_token(token);
+       return ret;
+}
+
+void __init opal_psr_init(void)
+{
+       struct device_node *psr, *node;
+       int i = 0;
+
+       psr = of_find_compatible_node(NULL, NULL,
+                                     "ibm,opal-power-shift-ratio");
+       if (!psr) {
+               pr_devel("Power-shift-ratio node not found\n");
+               return;
+       }
+
+       psr_attrs = kcalloc(of_get_child_count(psr), sizeof(struct psr_attr),
+                           GFP_KERNEL);
+       if (!psr_attrs)
+               return;
+
+       psr_kobj = kobject_create_and_add("psr", opal_kobj);
+       if (!psr_kobj) {
+               pr_warn("Failed to create psr kobject\n");
+               goto out;
+       }
+
+       for_each_child_of_node(psr, node) {
+               if (of_property_read_u32(node, "handle",
+                                        &psr_attrs[i].handle))
+                       goto out_kobj;
+
+               sysfs_attr_init(&psr_attrs[i].attr.attr);
+               if (of_property_read_string(node, "label",
+                                           &psr_attrs[i].attr.attr.name))
+                       goto out_kobj;
+               psr_attrs[i].attr.attr.mode = 0664;
+               psr_attrs[i].attr.show = psr_show;
+               psr_attrs[i].attr.store = psr_store;
+               if (sysfs_create_file(psr_kobj, &psr_attrs[i].attr.attr)) {
+                       pr_devel("Failed to create psr sysfs file %s\n",
+                                psr_attrs[i].attr.attr.name);
+                       goto out_kobj;
+               }
+               i++;
+       }
+
+       return;
+out_kobj:
+       kobject_put(psr_kobj);
+out:
+       kfree(psr_attrs);
+}
index 139286c9880838bed77afafb5ea2dc1499332b23..09cc6ec92af72d3e8476673ca33b5324c1ebe647 100644 (file)
@@ -316,3 +316,5 @@ 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);
+OPAL_CALL(opal_get_power_shift_ratio,          OPAL_GET_POWER_SHIFT_RATIO);
+OPAL_CALL(opal_set_power_shift_ratio,          OPAL_SET_POWER_SHIFT_RATIO);
index 28323c75e672fec59e64703bff1d03b44f9698d4..f659edbc50567f6af9a16eab065964661da758bd 100644 (file)
@@ -853,6 +853,9 @@ static int __init opal_init(void)
        /* Initialise OPAL powercap interface */
        opal_powercap_init();
 
+       /* Initialise OPAL Power-Shifting-Ratio interface */
+       opal_psr_init();
+
        return 0;
 }
 machine_subsys_initcall(powernv, opal_init);