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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/powerpc/platforms/powernv/opal-sysparam.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/powerpc/platforms/powernv/opal-sysparam.c')
-rw-r--r-- | arch/powerpc/platforms/powernv/opal-sysparam.c | 294 |
1 files changed, 294 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/powernv/opal-sysparam.c b/arch/powerpc/platforms/powernv/opal-sysparam.c new file mode 100644 index 000000000..a12312afe --- /dev/null +++ b/arch/powerpc/platforms/powernv/opal-sysparam.c @@ -0,0 +1,294 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * PowerNV system parameter code + * + * Copyright (C) 2013 IBM + */ + +#include <linux/kobject.h> +#include <linux/mutex.h> +#include <linux/slab.h> +#include <linux/of.h> +#include <linux/gfp.h> +#include <linux/stat.h> +#include <asm/opal.h> + +#define MAX_PARAM_DATA_LEN 64 + +static DEFINE_MUTEX(opal_sysparam_mutex); +static struct kobject *sysparam_kobj; +static void *param_data_buf; + +struct param_attr { + struct list_head list; + u32 param_id; + u32 param_size; + struct kobj_attribute kobj_attr; +}; + +static ssize_t opal_get_sys_param(u32 param_id, u32 length, void *buffer) +{ + struct opal_msg msg; + ssize_t ret; + int token; + + token = opal_async_get_token_interruptible(); + if (token < 0) { + if (token != -ERESTARTSYS) + pr_err("%s: Couldn't get the token, returning\n", + __func__); + ret = token; + goto out; + } + + ret = opal_get_param(token, param_id, (u64)buffer, length); + if (ret != OPAL_ASYNC_COMPLETION) { + ret = opal_error_code(ret); + goto out_token; + } + + ret = opal_async_wait_response(token, &msg); + if (ret) { + pr_err("%s: Failed to wait for the async response, %zd\n", + __func__, ret); + goto out_token; + } + + ret = opal_error_code(opal_get_async_rc(msg)); + +out_token: + opal_async_release_token(token); +out: + return ret; +} + +static int opal_set_sys_param(u32 param_id, u32 length, void *buffer) +{ + struct opal_msg msg; + int ret, token; + + token = opal_async_get_token_interruptible(); + if (token < 0) { + if (token != -ERESTARTSYS) + pr_err("%s: Couldn't get the token, returning\n", + __func__); + ret = token; + goto out; + } + + ret = opal_set_param(token, param_id, (u64)buffer, length); + + if (ret != OPAL_ASYNC_COMPLETION) { + ret = opal_error_code(ret); + goto out_token; + } + + ret = opal_async_wait_response(token, &msg); + if (ret) { + pr_err("%s: Failed to wait for the async response, %d\n", + __func__, ret); + goto out_token; + } + + ret = opal_error_code(opal_get_async_rc(msg)); + +out_token: + opal_async_release_token(token); +out: + return ret; +} + +static ssize_t sys_param_show(struct kobject *kobj, + struct kobj_attribute *kobj_attr, char *buf) +{ + struct param_attr *attr = container_of(kobj_attr, struct param_attr, + kobj_attr); + ssize_t ret; + + mutex_lock(&opal_sysparam_mutex); + ret = opal_get_sys_param(attr->param_id, attr->param_size, + param_data_buf); + if (ret) + goto out; + + memcpy(buf, param_data_buf, attr->param_size); + + ret = attr->param_size; +out: + mutex_unlock(&opal_sysparam_mutex); + return ret; +} + +static ssize_t sys_param_store(struct kobject *kobj, + struct kobj_attribute *kobj_attr, const char *buf, size_t count) +{ + struct param_attr *attr = container_of(kobj_attr, struct param_attr, + kobj_attr); + ssize_t ret; + + /* MAX_PARAM_DATA_LEN is sizeof(param_data_buf) */ + if (count > MAX_PARAM_DATA_LEN) + count = MAX_PARAM_DATA_LEN; + + mutex_lock(&opal_sysparam_mutex); + memcpy(param_data_buf, buf, count); + ret = opal_set_sys_param(attr->param_id, attr->param_size, + param_data_buf); + mutex_unlock(&opal_sysparam_mutex); + if (!ret) + ret = count; + return ret; +} + +void __init opal_sys_param_init(void) +{ + struct device_node *sysparam; + struct param_attr *attr; + u32 *id, *size; + int count, i; + u8 *perm; + + if (!opal_kobj) { + pr_warn("SYSPARAM: opal kobject is not available\n"); + goto out; + } + + /* Some systems do not use sysparams; this is not an error */ + sysparam = of_find_node_by_path("/ibm,opal/sysparams"); + if (!sysparam) + goto out; + + if (!of_device_is_compatible(sysparam, "ibm,opal-sysparams")) { + pr_err("SYSPARAM: Opal sysparam node not compatible\n"); + goto out_node_put; + } + + sysparam_kobj = kobject_create_and_add("sysparams", opal_kobj); + if (!sysparam_kobj) { + pr_err("SYSPARAM: Failed to create sysparam kobject\n"); + goto out_node_put; + } + + /* Allocate big enough buffer for any get/set transactions */ + param_data_buf = kzalloc(MAX_PARAM_DATA_LEN, GFP_KERNEL); + if (!param_data_buf) { + pr_err("SYSPARAM: Failed to allocate memory for param data " + "buf\n"); + goto out_kobj_put; + } + + /* Number of parameters exposed through DT */ + count = of_property_count_strings(sysparam, "param-name"); + if (count < 0) { + pr_err("SYSPARAM: No string found of property param-name in " + "the node %pOFn\n", sysparam); + goto out_param_buf; + } + + id = kcalloc(count, sizeof(*id), GFP_KERNEL); + if (!id) { + pr_err("SYSPARAM: Failed to allocate memory to read parameter " + "id\n"); + goto out_param_buf; + } + + size = kcalloc(count, sizeof(*size), GFP_KERNEL); + if (!size) { + pr_err("SYSPARAM: Failed to allocate memory to read parameter " + "size\n"); + goto out_free_id; + } + + perm = kcalloc(count, sizeof(*perm), GFP_KERNEL); + if (!perm) { + pr_err("SYSPARAM: Failed to allocate memory to read supported " + "action on the parameter"); + goto out_free_size; + } + + if (of_property_read_u32_array(sysparam, "param-id", id, count)) { + pr_err("SYSPARAM: Missing property param-id in the DT\n"); + goto out_free_perm; + } + + if (of_property_read_u32_array(sysparam, "param-len", size, count)) { + pr_err("SYSPARAM: Missing property param-len in the DT\n"); + goto out_free_perm; + } + + + if (of_property_read_u8_array(sysparam, "param-perm", perm, count)) { + pr_err("SYSPARAM: Missing property param-perm in the DT\n"); + goto out_free_perm; + } + + attr = kcalloc(count, sizeof(*attr), GFP_KERNEL); + if (!attr) { + pr_err("SYSPARAM: Failed to allocate memory for parameter " + "attributes\n"); + goto out_free_perm; + } + + /* For each of the parameters, populate the parameter attributes */ + for (i = 0; i < count; i++) { + if (size[i] > MAX_PARAM_DATA_LEN) { + pr_warn("SYSPARAM: Not creating parameter %d as size " + "exceeds buffer length\n", i); + continue; + } + + sysfs_attr_init(&attr[i].kobj_attr.attr); + attr[i].param_id = id[i]; + attr[i].param_size = size[i]; + if (of_property_read_string_index(sysparam, "param-name", i, + &attr[i].kobj_attr.attr.name)) + continue; + + /* If the parameter is read-only or read-write */ + switch (perm[i] & 3) { + case OPAL_SYSPARAM_READ: + attr[i].kobj_attr.attr.mode = 0444; + break; + case OPAL_SYSPARAM_WRITE: + attr[i].kobj_attr.attr.mode = 0200; + break; + case OPAL_SYSPARAM_RW: + attr[i].kobj_attr.attr.mode = 0644; + break; + default: + break; + } + + attr[i].kobj_attr.show = sys_param_show; + attr[i].kobj_attr.store = sys_param_store; + + if (sysfs_create_file(sysparam_kobj, &attr[i].kobj_attr.attr)) { + pr_err("SYSPARAM: Failed to create sysfs file %s\n", + attr[i].kobj_attr.attr.name); + goto out_free_attr; + } + } + + kfree(perm); + kfree(size); + kfree(id); + of_node_put(sysparam); + return; + +out_free_attr: + kfree(attr); +out_free_perm: + kfree(perm); +out_free_size: + kfree(size); +out_free_id: + kfree(id); +out_param_buf: + kfree(param_data_buf); +out_kobj_put: + kobject_put(sysparam_kobj); +out_node_put: + of_node_put(sysparam); +out: + return; +} |