diff options
Diffstat (limited to 'arch/powerpc/platforms/powernv/opal-powercap.c')
| -rw-r--r-- | arch/powerpc/platforms/powernv/opal-powercap.c | 244 |
1 files changed, 244 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/powernv/opal-powercap.c b/arch/powerpc/platforms/powernv/opal-powercap.c new file mode 100644 index 000000000..badb29bde --- /dev/null +++ b/arch/powerpc/platforms/powernv/opal-powercap.c @@ -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); +} |