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239 lines
4.5 KiB
239 lines
4.5 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Privileged ADI driver for sparc64 |
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* |
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* Author: Tom Hromatka <[email protected]> |
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*/ |
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#include <linux/kernel.h> |
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#include <linux/miscdevice.h> |
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#include <linux/module.h> |
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#include <linux/proc_fs.h> |
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#include <linux/slab.h> |
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#include <linux/uaccess.h> |
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#include <asm/asi.h> |
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#define MAX_BUF_SZ PAGE_SIZE |
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static int adi_open(struct inode *inode, struct file *file) |
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{ |
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file->f_mode |= FMODE_UNSIGNED_OFFSET; |
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return 0; |
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} |
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static int read_mcd_tag(unsigned long addr) |
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{ |
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long err; |
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int ver; |
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__asm__ __volatile__( |
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"1: ldxa [%[addr]] %[asi], %[ver]\n" |
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" mov 0, %[err]\n" |
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"2:\n" |
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" .section .fixup,#alloc,#execinstr\n" |
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" .align 4\n" |
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"3: sethi %%hi(2b), %%g1\n" |
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" jmpl %%g1 + %%lo(2b), %%g0\n" |
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" mov %[invalid], %[err]\n" |
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" .previous\n" |
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" .section __ex_table, \"a\"\n" |
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" .align 4\n" |
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" .word 1b, 3b\n" |
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" .previous\n" |
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: [ver] "=r" (ver), [err] "=r" (err) |
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: [addr] "r" (addr), [invalid] "i" (EFAULT), |
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[asi] "i" (ASI_MCD_REAL) |
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: "memory", "g1" |
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); |
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if (err) |
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return -EFAULT; |
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else |
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return ver; |
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} |
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static ssize_t adi_read(struct file *file, char __user *buf, |
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size_t count, loff_t *offp) |
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{ |
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size_t ver_buf_sz, bytes_read = 0; |
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int ver_buf_idx = 0; |
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loff_t offset; |
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u8 *ver_buf; |
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ssize_t ret; |
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ver_buf_sz = min_t(size_t, count, MAX_BUF_SZ); |
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ver_buf = kmalloc(ver_buf_sz, GFP_KERNEL); |
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if (!ver_buf) |
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return -ENOMEM; |
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offset = (*offp) * adi_blksize(); |
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while (bytes_read < count) { |
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ret = read_mcd_tag(offset); |
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if (ret < 0) |
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goto out; |
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ver_buf[ver_buf_idx] = (u8)ret; |
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ver_buf_idx++; |
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offset += adi_blksize(); |
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if (ver_buf_idx >= ver_buf_sz) { |
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if (copy_to_user(buf + bytes_read, ver_buf, |
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ver_buf_sz)) { |
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ret = -EFAULT; |
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goto out; |
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} |
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bytes_read += ver_buf_sz; |
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ver_buf_idx = 0; |
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ver_buf_sz = min(count - bytes_read, |
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(size_t)MAX_BUF_SZ); |
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} |
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} |
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(*offp) += bytes_read; |
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ret = bytes_read; |
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out: |
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kfree(ver_buf); |
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return ret; |
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} |
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static int set_mcd_tag(unsigned long addr, u8 ver) |
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{ |
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long err; |
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__asm__ __volatile__( |
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"1: stxa %[ver], [%[addr]] %[asi]\n" |
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" mov 0, %[err]\n" |
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"2:\n" |
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" .section .fixup,#alloc,#execinstr\n" |
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" .align 4\n" |
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"3: sethi %%hi(2b), %%g1\n" |
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" jmpl %%g1 + %%lo(2b), %%g0\n" |
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" mov %[invalid], %[err]\n" |
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" .previous\n" |
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" .section __ex_table, \"a\"\n" |
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" .align 4\n" |
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" .word 1b, 3b\n" |
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" .previous\n" |
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: [err] "=r" (err) |
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: [ver] "r" (ver), [addr] "r" (addr), |
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[invalid] "i" (EFAULT), [asi] "i" (ASI_MCD_REAL) |
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: "memory", "g1" |
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); |
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if (err) |
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return -EFAULT; |
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else |
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return ver; |
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} |
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static ssize_t adi_write(struct file *file, const char __user *buf, |
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size_t count, loff_t *offp) |
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{ |
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size_t ver_buf_sz, bytes_written = 0; |
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loff_t offset; |
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u8 *ver_buf; |
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ssize_t ret; |
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int i; |
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if (count <= 0) |
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return -EINVAL; |
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ver_buf_sz = min_t(size_t, count, MAX_BUF_SZ); |
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ver_buf = kmalloc(ver_buf_sz, GFP_KERNEL); |
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if (!ver_buf) |
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return -ENOMEM; |
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offset = (*offp) * adi_blksize(); |
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do { |
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if (copy_from_user(ver_buf, &buf[bytes_written], |
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ver_buf_sz)) { |
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ret = -EFAULT; |
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goto out; |
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} |
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for (i = 0; i < ver_buf_sz; i++) { |
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ret = set_mcd_tag(offset, ver_buf[i]); |
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if (ret < 0) |
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goto out; |
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offset += adi_blksize(); |
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} |
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bytes_written += ver_buf_sz; |
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ver_buf_sz = min(count - bytes_written, (size_t)MAX_BUF_SZ); |
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} while (bytes_written < count); |
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(*offp) += bytes_written; |
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ret = bytes_written; |
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out: |
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__asm__ __volatile__("membar #Sync"); |
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kfree(ver_buf); |
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return ret; |
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} |
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static loff_t adi_llseek(struct file *file, loff_t offset, int whence) |
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{ |
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loff_t ret = -EINVAL; |
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switch (whence) { |
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case SEEK_END: |
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case SEEK_DATA: |
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case SEEK_HOLE: |
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/* unsupported */ |
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return -EINVAL; |
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case SEEK_CUR: |
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if (offset == 0) |
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return file->f_pos; |
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offset += file->f_pos; |
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break; |
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case SEEK_SET: |
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break; |
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} |
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if (offset != file->f_pos) { |
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file->f_pos = offset; |
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file->f_version = 0; |
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ret = offset; |
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} |
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return ret; |
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} |
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static const struct file_operations adi_fops = { |
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.owner = THIS_MODULE, |
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.llseek = adi_llseek, |
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.open = adi_open, |
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.read = adi_read, |
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.write = adi_write, |
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}; |
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static struct miscdevice adi_miscdev = { |
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.minor = MISC_DYNAMIC_MINOR, |
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.name = KBUILD_MODNAME, |
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.fops = &adi_fops, |
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}; |
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static int __init adi_init(void) |
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{ |
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if (!adi_capable()) |
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return -EPERM; |
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return misc_register(&adi_miscdev); |
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} |
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static void __exit adi_exit(void) |
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{ |
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misc_deregister(&adi_miscdev); |
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} |
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module_init(adi_init); |
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module_exit(adi_exit); |
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MODULE_AUTHOR("Tom Hromatka <[email protected]>"); |
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MODULE_DESCRIPTION("Privileged interface to ADI"); |
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MODULE_VERSION("1.0"); |
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MODULE_LICENSE("GPL v2");
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