[PATCH] powerpc/powernv: Enable reading and updating of system parameters
Neelesh Gupta
neelegup at linux.vnet.ibm.com
Fri Mar 7 16:32:09 EST 2014
This patch enables reading and updating of system parameters through
OPAL call.
Signed-off-by: Neelesh Gupta <neelegup at linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
---
arch/powerpc/include/asm/opal.h | 14 +
arch/powerpc/platforms/powernv/Makefile | 2
arch/powerpc/platforms/powernv/opal-sysparam.c | 290 ++++++++++++++++++++++++
arch/powerpc/platforms/powernv/opal-wrappers.S | 2
arch/powerpc/platforms/powernv/opal.c | 2
5 files changed, 309 insertions(+), 1 deletion(-)
create mode 100644 arch/powerpc/platforms/powernv/opal-sysparam.c
diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h
index 90fad59..60b3edc 100644
--- a/arch/powerpc/include/asm/opal.h
+++ b/arch/powerpc/include/asm/opal.h
@@ -159,6 +159,8 @@ extern int opal_enter_rtas(struct rtas_args *args,
#define OPAL_GET_MSG 85
#define OPAL_CHECK_ASYNC_COMPLETION 86
#define OPAL_SYNC_HOST_REBOOT 87
+#define OPAL_GET_PARAM 89
+#define OPAL_SET_PARAM 90
#ifndef __ASSEMBLY__
@@ -398,6 +400,13 @@ enum OpalLPCAddressType {
OPAL_LPC_FW = 2,
};
+/* System parameter permission */
+enum OpalSysparamPerm {
+ OPAL_SYSPARAM_READ = 0x1,
+ OPAL_SYSPARAM_WRITE = 0x2,
+ OPAL_SYSPARAM_RW = (OPAL_SYSPARAM_READ | OPAL_SYSPARAM_WRITE),
+};
+
struct opal_msg {
uint32_t msg_type;
uint32_t reserved;
@@ -834,6 +843,10 @@ int64_t opal_update_flash(uint64_t blk_list);
int64_t opal_get_msg(uint64_t buffer, size_t size);
int64_t opal_check_completion(uint64_t buffer, size_t size, uint64_t token);
int64_t opal_sync_host_reboot(void);
+int64_t opal_get_param(uint64_t token, uint32_t param_id, uint64_t buffer,
+ size_t length);
+int64_t opal_set_param(uint64_t token, uint32_t param_id, uint64_t buffer,
+ size_t length);
/* Internal functions */
extern int early_init_dt_scan_opal(unsigned long node, const char *uname, int depth, void *data);
@@ -871,6 +884,7 @@ extern void opal_get_rtc_time(struct rtc_time *tm);
extern unsigned long opal_get_boot_time(void);
extern void opal_nvram_init(void);
extern void opal_flash_init(void);
+extern void opal_sys_param_init(void);
extern int opal_machine_check(struct pt_regs *regs);
diff --git a/arch/powerpc/platforms/powernv/Makefile b/arch/powerpc/platforms/powernv/Makefile
index c0f85ea..e6166d3 100644
--- a/arch/powerpc/platforms/powernv/Makefile
+++ b/arch/powerpc/platforms/powernv/Makefile
@@ -1,5 +1,5 @@
obj-y += setup.o opal-takeover.o opal-wrappers.o opal.o opal-async.o
-obj-y += opal-rtc.o opal-nvram.o opal-lpc.o opal-flash.o
+obj-y += opal-rtc.o opal-nvram.o opal-lpc.o opal-flash.o opal-sysparam.o
obj-y += rng.o
obj-$(CONFIG_SMP) += smp.o
diff --git a/arch/powerpc/platforms/powernv/opal-sysparam.c b/arch/powerpc/platforms/powernv/opal-sysparam.c
new file mode 100644
index 0000000..0bd249a
--- /dev/null
+++ b/arch/powerpc/platforms/powernv/opal-sysparam.c
@@ -0,0 +1,290 @@
+/*
+ * PowerNV system parameter code
+ *
+ * Copyright (C) 2013 IBM
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#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 int opal_get_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_get_param(token, param_id, (u64)buffer, length);
+ if (ret != OPAL_ASYNC_COMPLETION)
+ 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 = msg.params[1];
+
+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)
+ 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 = msg.params[1];
+
+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);
+ int 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);
+
+out:
+ mutex_unlock(&opal_sysparam_mutex);
+ return ret ? ret : attr->param_size;
+}
+
+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);
+ int ret;
+
+ 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);
+ return ret ? ret : count;
+}
+
+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;
+ }
+
+ sysparam_kobj = kobject_create_and_add("sysparams", opal_kobj);
+ if (!sysparam_kobj) {
+ pr_err("SYSPARAM: Failed to create sysparam kobject\n");
+ goto out;
+ }
+
+ /* 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;
+ }
+
+ sysparam = of_find_node_by_path("/ibm,opal/sysparams");
+ if (!sysparam) {
+ pr_err("SYSPARAM: Opal sysparam node not found\n");
+ goto out_param_buf;
+ }
+
+ if (!of_device_is_compatible(sysparam, "ibm,opal-sysparams")) {
+ pr_err("SYSPARAM: Opal sysparam node not compatible\n");
+ goto out_node_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 %s\n", sysparam->name);
+ goto out_node_put;
+ }
+
+ id = kzalloc(sizeof(*id) * count, GFP_KERNEL);
+ if (!id) {
+ pr_err("SYSPARAM: Failed to allocate memory to read parameter "
+ "id\n");
+ goto out_node_put;
+ }
+
+ size = kzalloc(sizeof(*size) * count, GFP_KERNEL);
+ if (!size) {
+ pr_err("SYSPARAM: Failed to allocate memory to read parameter "
+ "size\n");
+ goto out_free_id;
+ }
+
+ perm = kzalloc(sizeof(*perm) * count, 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 propery 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 propery param-perm in the DT\n");
+ goto out_free_perm;
+ }
+
+ attr = kzalloc(sizeof(*attr) * count, 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++) {
+ 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 = S_IRUGO;
+ break;
+ case OPAL_SYSPARAM_WRITE:
+ attr[i].kobj_attr.attr.mode = S_IWUGO;
+ break;
+ case OPAL_SYSPARAM_RW:
+ attr[i].kobj_attr.attr.mode = S_IRUGO | S_IWUGO;
+ 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_node_put:
+ of_node_put(sysparam);
+out_param_buf:
+ kfree(param_data_buf);
+out_kobj_put:
+ kobject_put(sysparam_kobj);
+out:
+ return;
+}
diff --git a/arch/powerpc/platforms/powernv/opal-wrappers.S b/arch/powerpc/platforms/powernv/opal-wrappers.S
index 3e8829c..0afdeca 100644
--- a/arch/powerpc/platforms/powernv/opal-wrappers.S
+++ b/arch/powerpc/platforms/powernv/opal-wrappers.S
@@ -129,3 +129,5 @@ OPAL_CALL(opal_update_flash, OPAL_FLASH_UPDATE);
OPAL_CALL(opal_get_msg, OPAL_GET_MSG);
OPAL_CALL(opal_check_completion, OPAL_CHECK_ASYNC_COMPLETION);
OPAL_CALL(opal_sync_host_reboot, OPAL_SYNC_HOST_REBOOT);
+OPAL_CALL(opal_get_param, OPAL_GET_PARAM);
+OPAL_CALL(opal_set_param, OPAL_SET_PARAM);
diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c
index 65499ad..4fad36a 100644
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -474,6 +474,8 @@ static int __init opal_init(void)
if (rc == 0) {
/* Setup code update interface */
opal_flash_init();
+ /* Setup system parameters interface */
+ opal_sys_param_init();
}
return 0;
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