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Diffstat (limited to 'arch/alpha/kernel/srm_env.c')
-rw-r--r--arch/alpha/kernel/srm_env.c335
1 files changed, 335 insertions, 0 deletions
diff --git a/arch/alpha/kernel/srm_env.c b/arch/alpha/kernel/srm_env.c
new file mode 100644
index 00000000000..5c98fc83e23
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+++ b/arch/alpha/kernel/srm_env.c
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+/*
+ * srm_env.c - Access to SRM environment
+ * variables through linux' procfs
+ *
+ * Copyright (C) 2001-2002 Jan-Benedict Glaw <jbglaw@lug-owl.de>
+ *
+ * This driver is at all a modified version of Erik Mouw's
+ * Documentation/DocBook/procfs_example.c, so: thank
+ * you, Erik! He can be reached via email at
+ * <J.A.K.Mouw@its.tudelft.nl>. It is based on an idea
+ * provided by DEC^WCompaq^WIntel's "Jumpstart" CD. They
+ * included a patch like this as well. Thanks for idea!
+ *
+ * This program is free software; you can redistribute
+ * it and/or modify it under the terms of the GNU General
+ * Public License version 2 as published by the Free Software
+ * Foundation.
+ *
+ * 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
+ *
+ */
+
+/*
+ * Changelog
+ * ~~~~~~~~~
+ *
+ * Thu, 22 Aug 2002 15:10:43 +0200
+ * - Update Config.help entry. I got a number of emails asking
+ * me to tell their senders if they could make use of this
+ * piece of code... So: "SRM is something like BIOS for your
+ * Alpha"
+ * - Update code formatting a bit to better conform CodingStyle
+ * rules.
+ * - So this is v0.0.5, with no changes (except formatting)
+ *
+ * Wed, 22 May 2002 00:11:21 +0200
+ * - Fix typo on comment (SRC -> SRM)
+ * - Call this "Version 0.0.4"
+ *
+ * Tue, 9 Apr 2002 18:44:40 +0200
+ * - Implement access by variable name and additionally
+ * by number. This is done by creating two subdirectories
+ * where one holds all names (like the old directory
+ * did) and the other holding 256 files named like "0",
+ * "1" and so on.
+ * - Call this "Version 0.0.3"
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/proc_fs.h>
+#include <asm/console.h>
+#include <asm/uaccess.h>
+#include <asm/machvec.h>
+
+#define BASE_DIR "srm_environment" /* Subdir in /proc/ */
+#define NAMED_DIR "named_variables" /* Subdir for known variables */
+#define NUMBERED_DIR "numbered_variables" /* Subdir for all variables */
+#define VERSION "0.0.5" /* Module version */
+#define NAME "srm_env" /* Module name */
+
+MODULE_AUTHOR("Jan-Benedict Glaw <jbglaw@lug-owl.de>");
+MODULE_DESCRIPTION("Accessing Alpha SRM environment through procfs interface");
+MODULE_LICENSE("GPL");
+
+typedef struct _srm_env {
+ char *name;
+ unsigned long id;
+ struct proc_dir_entry *proc_entry;
+} srm_env_t;
+
+static struct proc_dir_entry *base_dir;
+static struct proc_dir_entry *named_dir;
+static struct proc_dir_entry *numbered_dir;
+static char number[256][4];
+
+static srm_env_t srm_named_entries[] = {
+ { "auto_action", ENV_AUTO_ACTION },
+ { "boot_dev", ENV_BOOT_DEV },
+ { "bootdef_dev", ENV_BOOTDEF_DEV },
+ { "booted_dev", ENV_BOOTED_DEV },
+ { "boot_file", ENV_BOOT_FILE },
+ { "booted_file", ENV_BOOTED_FILE },
+ { "boot_osflags", ENV_BOOT_OSFLAGS },
+ { "booted_osflags", ENV_BOOTED_OSFLAGS },
+ { "boot_reset", ENV_BOOT_RESET },
+ { "dump_dev", ENV_DUMP_DEV },
+ { "enable_audit", ENV_ENABLE_AUDIT },
+ { "license", ENV_LICENSE },
+ { "char_set", ENV_CHAR_SET },
+ { "language", ENV_LANGUAGE },
+ { "tty_dev", ENV_TTY_DEV },
+ { NULL, 0 },
+};
+static srm_env_t srm_numbered_entries[256];
+
+
+
+static int
+srm_env_read(char *page, char **start, off_t off, int count, int *eof,
+ void *data)
+{
+ int nbytes;
+ unsigned long ret;
+ srm_env_t *entry;
+
+ if(off != 0)
+ return -EFAULT;
+
+ entry = (srm_env_t *) data;
+ ret = callback_getenv(entry->id, page, count);
+
+ if((ret >> 61) == 0)
+ nbytes = (int) ret;
+ else
+ nbytes = -EFAULT;
+
+ return nbytes;
+}
+
+
+static int
+srm_env_write(struct file *file, const char __user *buffer, unsigned long count,
+ void *data)
+{
+ int res;
+ srm_env_t *entry;
+ char *buf = (char *) __get_free_page(GFP_USER);
+ unsigned long ret1, ret2;
+
+ entry = (srm_env_t *) data;
+
+ if (!buf)
+ return -ENOMEM;
+
+ res = -EINVAL;
+ if (count >= PAGE_SIZE)
+ goto out;
+
+ res = -EFAULT;
+ if (copy_from_user(buf, buffer, count))
+ goto out;
+ buf[count] = '\0';
+
+ ret1 = callback_setenv(entry->id, buf, count);
+ if ((ret1 >> 61) == 0) {
+ do
+ ret2 = callback_save_env();
+ while((ret2 >> 61) == 1);
+ res = (int) ret1;
+ }
+
+ out:
+ free_page((unsigned long)buf);
+ return res;
+}
+
+static void
+srm_env_cleanup(void)
+{
+ srm_env_t *entry;
+ unsigned long var_num;
+
+ if(base_dir) {
+ /*
+ * Remove named entries
+ */
+ if(named_dir) {
+ entry = srm_named_entries;
+ while(entry->name != NULL && entry->id != 0) {
+ if(entry->proc_entry) {
+ remove_proc_entry(entry->name,
+ named_dir);
+ entry->proc_entry = NULL;
+ }
+ entry++;
+ }
+ remove_proc_entry(NAMED_DIR, base_dir);
+ }
+
+ /*
+ * Remove numbered entries
+ */
+ if(numbered_dir) {
+ for(var_num = 0; var_num <= 255; var_num++) {
+ entry = &srm_numbered_entries[var_num];
+
+ if(entry->proc_entry) {
+ remove_proc_entry(entry->name,
+ numbered_dir);
+ entry->proc_entry = NULL;
+ entry->name = NULL;
+ }
+ }
+ remove_proc_entry(NUMBERED_DIR, base_dir);
+ }
+
+ remove_proc_entry(BASE_DIR, NULL);
+ }
+
+ return;
+}
+
+
+static int __init
+srm_env_init(void)
+{
+ srm_env_t *entry;
+ unsigned long var_num;
+
+ /*
+ * Check system
+ */
+ if(!alpha_using_srm) {
+ printk(KERN_INFO "%s: This Alpha system doesn't "
+ "know about SRM (or you've booted "
+ "SRM->MILO->Linux, which gets "
+ "misdetected)...\n", __FUNCTION__);
+ return -ENODEV;
+ }
+
+ /*
+ * Init numbers
+ */
+ for(var_num = 0; var_num <= 255; var_num++)
+ sprintf(number[var_num], "%ld", var_num);
+
+ /*
+ * Create base directory
+ */
+ base_dir = proc_mkdir(BASE_DIR, NULL);
+ if(base_dir == NULL) {
+ printk(KERN_ERR "Couldn't create base dir /proc/%s\n",
+ BASE_DIR);
+ goto cleanup;
+ }
+ base_dir->owner = THIS_MODULE;
+
+ /*
+ * Create per-name subdirectory
+ */
+ named_dir = proc_mkdir(NAMED_DIR, base_dir);
+ if(named_dir == NULL) {
+ printk(KERN_ERR "Couldn't create dir /proc/%s/%s\n",
+ BASE_DIR, NAMED_DIR);
+ goto cleanup;
+ }
+ named_dir->owner = THIS_MODULE;
+
+ /*
+ * Create per-number subdirectory
+ */
+ numbered_dir = proc_mkdir(NUMBERED_DIR, base_dir);
+ if(numbered_dir == NULL) {
+ printk(KERN_ERR "Couldn't create dir /proc/%s/%s\n",
+ BASE_DIR, NUMBERED_DIR);
+ goto cleanup;
+
+ }
+ numbered_dir->owner = THIS_MODULE;
+
+ /*
+ * Create all named nodes
+ */
+ entry = srm_named_entries;
+ while(entry->name != NULL && entry->id != 0) {
+ entry->proc_entry = create_proc_entry(entry->name,
+ 0644, named_dir);
+ if(entry->proc_entry == NULL)
+ goto cleanup;
+
+ entry->proc_entry->data = (void *) entry;
+ entry->proc_entry->owner = THIS_MODULE;
+ entry->proc_entry->read_proc = srm_env_read;
+ entry->proc_entry->write_proc = srm_env_write;
+
+ entry++;
+ }
+
+ /*
+ * Create all numbered nodes
+ */
+ for(var_num = 0; var_num <= 255; var_num++) {
+ entry = &srm_numbered_entries[var_num];
+ entry->name = number[var_num];
+
+ entry->proc_entry = create_proc_entry(entry->name,
+ 0644, numbered_dir);
+ if(entry->proc_entry == NULL)
+ goto cleanup;
+
+ entry->id = var_num;
+ entry->proc_entry->data = (void *) entry;
+ entry->proc_entry->owner = THIS_MODULE;
+ entry->proc_entry->read_proc = srm_env_read;
+ entry->proc_entry->write_proc = srm_env_write;
+ }
+
+ printk(KERN_INFO "%s: version %s loaded successfully\n", NAME,
+ VERSION);
+
+ return 0;
+
+cleanup:
+ srm_env_cleanup();
+
+ return -ENOMEM;
+}
+
+
+static void __exit
+srm_env_exit(void)
+{
+ srm_env_cleanup();
+ printk(KERN_INFO "%s: unloaded successfully\n", NAME);
+
+ return;
+}
+
+
+module_init(srm_env_init);
+module_exit(srm_env_exit);
+