Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / char / generic_nvram.c

diff --git a/kernel/drivers/char/generic_nvram.c b/kernel/drivers/char/generic_nvram.c
new file mode 100644 (file)
index 0000000..6c4f4b5
--- /dev/null
+++ b/kernel/drivers/char/generic_nvram.c
@@ -0,0 +1,174 @@
+/*
+ * Generic /dev/nvram driver for architectures providing some
+ * "generic" hooks, that is :
+ *
+ * nvram_read_byte, nvram_write_byte, nvram_sync, nvram_get_size
+ *
+ * Note that an additional hook is supported for PowerMac only
+ * for getting the nvram "partition" informations
+ *
+ */
+
+#define NVRAM_VERSION "1.1"
+
+#include <linux/module.h>
+
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/miscdevice.h>
+#include <linux/fcntl.h>
+#include <linux/init.h>
+#include <linux/mutex.h>
+#include <asm/uaccess.h>
+#include <asm/nvram.h>
+#ifdef CONFIG_PPC_PMAC
+#include <asm/machdep.h>
+#endif
+
+#define NVRAM_SIZE     8192
+
+static DEFINE_MUTEX(nvram_mutex);
+static ssize_t nvram_len;
+
+static loff_t nvram_llseek(struct file *file, loff_t offset, int origin)
+{
+       switch (origin) {
+       case 0:
+               break;
+       case 1:
+               offset += file->f_pos;
+               break;
+       case 2:
+               offset += nvram_len;
+               break;
+       default:
+               offset = -1;
+       }
+       if (offset < 0)
+               return -EINVAL;
+
+       file->f_pos = offset;
+
+       return file->f_pos;
+}
+
+static ssize_t read_nvram(struct file *file, char __user *buf,
+                         size_t count, loff_t *ppos)
+{
+       unsigned int i;
+       char __user *p = buf;
+
+       if (!access_ok(VERIFY_WRITE, buf, count))
+               return -EFAULT;
+       if (*ppos >= nvram_len)
+               return 0;
+       for (i = *ppos; count > 0 && i < nvram_len; ++i, ++p, --count)
+               if (__put_user(nvram_read_byte(i), p))
+                       return -EFAULT;
+       *ppos = i;
+       return p - buf;
+}
+
+static ssize_t write_nvram(struct file *file, const char __user *buf,
+                          size_t count, loff_t *ppos)
+{
+       unsigned int i;
+       const char __user *p = buf;
+       char c;
+
+       if (!access_ok(VERIFY_READ, buf, count))
+               return -EFAULT;
+       if (*ppos >= nvram_len)
+               return 0;
+       for (i = *ppos; count > 0 && i < nvram_len; ++i, ++p, --count) {
+               if (__get_user(c, p))
+                       return -EFAULT;
+               nvram_write_byte(c, i);
+       }
+       *ppos = i;
+       return p - buf;
+}
+
+static int nvram_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+       switch(cmd) {
+#ifdef CONFIG_PPC_PMAC
+       case OBSOLETE_PMAC_NVRAM_GET_OFFSET:
+               printk(KERN_WARNING "nvram: Using obsolete PMAC_NVRAM_GET_OFFSET ioctl\n");
+       case IOC_NVRAM_GET_OFFSET: {
+               int part, offset;
+
+               if (!machine_is(powermac))
+                       return -EINVAL;
+               if (copy_from_user(&part, (void __user*)arg, sizeof(part)) != 0)
+                       return -EFAULT;
+               if (part < pmac_nvram_OF || part > pmac_nvram_NR)
+                       return -EINVAL;
+               offset = pmac_get_partition(part);
+               if (copy_to_user((void __user*)arg, &offset, sizeof(offset)) != 0)
+                       return -EFAULT;
+               break;
+       }
+#endif /* CONFIG_PPC_PMAC */
+       case IOC_NVRAM_SYNC:
+               nvram_sync();
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+static long nvram_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+       int ret;
+
+       mutex_lock(&nvram_mutex);
+       ret = nvram_ioctl(file, cmd, arg);
+       mutex_unlock(&nvram_mutex);
+
+       return ret;
+}
+
+const struct file_operations nvram_fops = {
+       .owner          = THIS_MODULE,
+       .llseek         = nvram_llseek,
+       .read           = read_nvram,
+       .write          = write_nvram,
+       .unlocked_ioctl = nvram_unlocked_ioctl,
+};
+
+static struct miscdevice nvram_dev = {
+       NVRAM_MINOR,
+       "nvram",
+       &nvram_fops
+};
+
+int __init nvram_init(void)
+{
+       int ret = 0;
+
+       printk(KERN_INFO "Generic non-volatile memory driver v%s\n",
+               NVRAM_VERSION);
+       ret = misc_register(&nvram_dev);
+       if (ret != 0)
+               goto out;
+
+       nvram_len = nvram_get_size();
+       if (nvram_len < 0)
+               nvram_len = NVRAM_SIZE;
+
+out:
+       return ret;
+}
+
+void __exit nvram_cleanup(void)
+{
+        misc_deregister( &nvram_dev );
+}
+
+module_init(nvram_init);
+module_exit(nvram_cleanup);
+MODULE_LICENSE("GPL");