powerpc/powernv: Enable reading and updating of system parameters
This patch enables reading and updating of system parameters through OPAL call. Signed-off-by: Neelesh Gupta <neelegup@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Neelesh Gupta
committed by
Benjamin Herrenschmidt
Benjamin Herrenschmidt
parent
8d72482322
commit
4029cd6654
290
arch/powerpc/platforms/powernv/opal-sysparam.c
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290
arch/powerpc/platforms/powernv/opal-sysparam.c
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@@ -0,0 +1,290 @@
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/*
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* PowerNV system parameter code
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*
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* Copyright (C) 2013 IBM
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <linux/kobject.h>
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#include <linux/mutex.h>
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#include <linux/slab.h>
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#include <linux/of.h>
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#include <linux/gfp.h>
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#include <linux/stat.h>
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#include <asm/opal.h>
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#define MAX_PARAM_DATA_LEN 64
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static DEFINE_MUTEX(opal_sysparam_mutex);
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static struct kobject *sysparam_kobj;
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static void *param_data_buf;
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struct param_attr {
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struct list_head list;
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u32 param_id;
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u32 param_size;
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struct kobj_attribute kobj_attr;
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};
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static int opal_get_sys_param(u32 param_id, u32 length, void *buffer)
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{
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struct opal_msg msg;
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int ret, token;
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token = opal_async_get_token_interruptible();
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if (token < 0) {
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if (token != -ERESTARTSYS)
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pr_err("%s: Couldn't get the token, returning\n",
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__func__);
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ret = token;
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goto out;
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}
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ret = opal_get_param(token, param_id, (u64)buffer, length);
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if (ret != OPAL_ASYNC_COMPLETION)
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goto out_token;
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ret = opal_async_wait_response(token, &msg);
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if (ret) {
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pr_err("%s: Failed to wait for the async response, %d\n",
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__func__, ret);
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goto out_token;
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}
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ret = msg.params[1];
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out_token:
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opal_async_release_token(token);
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out:
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return ret;
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}
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static int opal_set_sys_param(u32 param_id, u32 length, void *buffer)
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{
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struct opal_msg msg;
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int ret, token;
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token = opal_async_get_token_interruptible();
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if (token < 0) {
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if (token != -ERESTARTSYS)
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pr_err("%s: Couldn't get the token, returning\n",
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__func__);
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ret = token;
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goto out;
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}
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ret = opal_set_param(token, param_id, (u64)buffer, length);
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if (ret != OPAL_ASYNC_COMPLETION)
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goto out_token;
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ret = opal_async_wait_response(token, &msg);
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if (ret) {
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pr_err("%s: Failed to wait for the async response, %d\n",
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__func__, ret);
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goto out_token;
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}
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ret = msg.params[1];
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out_token:
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opal_async_release_token(token);
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out:
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return ret;
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}
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static ssize_t sys_param_show(struct kobject *kobj,
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struct kobj_attribute *kobj_attr, char *buf)
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{
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struct param_attr *attr = container_of(kobj_attr, struct param_attr,
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kobj_attr);
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int ret;
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mutex_lock(&opal_sysparam_mutex);
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ret = opal_get_sys_param(attr->param_id, attr->param_size,
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param_data_buf);
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if (ret)
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goto out;
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memcpy(buf, param_data_buf, attr->param_size);
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out:
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mutex_unlock(&opal_sysparam_mutex);
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return ret ? ret : attr->param_size;
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}
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static ssize_t sys_param_store(struct kobject *kobj,
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struct kobj_attribute *kobj_attr, const char *buf, size_t count)
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{
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struct param_attr *attr = container_of(kobj_attr, struct param_attr,
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kobj_attr);
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int ret;
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mutex_lock(&opal_sysparam_mutex);
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memcpy(param_data_buf, buf, count);
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ret = opal_set_sys_param(attr->param_id, attr->param_size,
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param_data_buf);
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mutex_unlock(&opal_sysparam_mutex);
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return ret ? ret : count;
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}
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void __init opal_sys_param_init(void)
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{
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struct device_node *sysparam;
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struct param_attr *attr;
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u32 *id, *size;
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int count, i;
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u8 *perm;
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if (!opal_kobj) {
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pr_warn("SYSPARAM: opal kobject is not available\n");
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goto out;
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}
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sysparam_kobj = kobject_create_and_add("sysparams", opal_kobj);
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if (!sysparam_kobj) {
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pr_err("SYSPARAM: Failed to create sysparam kobject\n");
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goto out;
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}
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/* Allocate big enough buffer for any get/set transactions */
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param_data_buf = kzalloc(MAX_PARAM_DATA_LEN, GFP_KERNEL);
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if (!param_data_buf) {
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pr_err("SYSPARAM: Failed to allocate memory for param data "
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"buf\n");
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goto out_kobj_put;
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}
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sysparam = of_find_node_by_path("/ibm,opal/sysparams");
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if (!sysparam) {
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pr_err("SYSPARAM: Opal sysparam node not found\n");
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goto out_param_buf;
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}
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if (!of_device_is_compatible(sysparam, "ibm,opal-sysparams")) {
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pr_err("SYSPARAM: Opal sysparam node not compatible\n");
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goto out_node_put;
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}
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/* Number of parameters exposed through DT */
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count = of_property_count_strings(sysparam, "param-name");
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if (count < 0) {
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pr_err("SYSPARAM: No string found of property param-name in "
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"the node %s\n", sysparam->name);
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goto out_node_put;
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}
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id = kzalloc(sizeof(*id) * count, GFP_KERNEL);
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if (!id) {
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pr_err("SYSPARAM: Failed to allocate memory to read parameter "
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"id\n");
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goto out_node_put;
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}
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size = kzalloc(sizeof(*size) * count, GFP_KERNEL);
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if (!size) {
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pr_err("SYSPARAM: Failed to allocate memory to read parameter "
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"size\n");
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goto out_free_id;
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}
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perm = kzalloc(sizeof(*perm) * count, GFP_KERNEL);
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if (!perm) {
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pr_err("SYSPARAM: Failed to allocate memory to read supported "
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"action on the parameter");
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goto out_free_size;
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}
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if (of_property_read_u32_array(sysparam, "param-id", id, count)) {
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pr_err("SYSPARAM: Missing property param-id in the DT\n");
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goto out_free_perm;
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}
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if (of_property_read_u32_array(sysparam, "param-len", size, count)) {
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pr_err("SYSPARAM: Missing propery param-len in the DT\n");
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goto out_free_perm;
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}
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if (of_property_read_u8_array(sysparam, "param-perm", perm, count)) {
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pr_err("SYSPARAM: Missing propery param-perm in the DT\n");
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goto out_free_perm;
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}
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attr = kzalloc(sizeof(*attr) * count, GFP_KERNEL);
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if (!attr) {
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pr_err("SYSPARAM: Failed to allocate memory for parameter "
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"attributes\n");
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goto out_free_perm;
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}
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/* For each of the parameters, populate the parameter attributes */
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for (i = 0; i < count; i++) {
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sysfs_attr_init(&attr[i].kobj_attr.attr);
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attr[i].param_id = id[i];
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attr[i].param_size = size[i];
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if (of_property_read_string_index(sysparam, "param-name", i,
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&attr[i].kobj_attr.attr.name))
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continue;
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/* If the parameter is read-only or read-write */
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switch (perm[i] & 3) {
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case OPAL_SYSPARAM_READ:
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attr[i].kobj_attr.attr.mode = S_IRUGO;
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break;
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case OPAL_SYSPARAM_WRITE:
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attr[i].kobj_attr.attr.mode = S_IWUGO;
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break;
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case OPAL_SYSPARAM_RW:
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attr[i].kobj_attr.attr.mode = S_IRUGO | S_IWUGO;
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break;
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default:
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break;
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}
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attr[i].kobj_attr.show = sys_param_show;
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attr[i].kobj_attr.store = sys_param_store;
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if (sysfs_create_file(sysparam_kobj, &attr[i].kobj_attr.attr)) {
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pr_err("SYSPARAM: Failed to create sysfs file %s\n",
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attr[i].kobj_attr.attr.name);
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goto out_free_attr;
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}
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}
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kfree(perm);
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kfree(size);
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kfree(id);
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of_node_put(sysparam);
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return;
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out_free_attr:
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kfree(attr);
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out_free_perm:
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kfree(perm);
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out_free_size:
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kfree(size);
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out_free_id:
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kfree(id);
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out_node_put:
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of_node_put(sysparam);
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out_param_buf:
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kfree(param_data_buf);
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out_kobj_put:
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kobject_put(sysparam_kobj);
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out:
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return;
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}
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