1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2020 Intel Corporation 4 */ 5 6 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 7 8 #include <linux/init.h> 9 #include <linux/module.h> 10 #include <linux/printk.h> 11 12 /* a tiny module only meant to test set/clear_bit */ 13 14 /* use an enum because thats the most common BITMAP usage */ 15 enum bitops_fun { 16 BITOPS_4 = 4, 17 BITOPS_7 = 7, 18 BITOPS_11 = 11, 19 BITOPS_31 = 31, 20 BITOPS_88 = 88, 21 BITOPS_LAST = 255, 22 BITOPS_LENGTH = 256 23 }; 24 25 static DECLARE_BITMAP(g_bitmap, BITOPS_LENGTH); 26 27 static int __init test_bitops_startup(void) 28 { 29 pr_warn("Loaded test module\n"); 30 set_bit(BITOPS_4, g_bitmap); 31 set_bit(BITOPS_7, g_bitmap); 32 set_bit(BITOPS_11, g_bitmap); 33 set_bit(BITOPS_31, g_bitmap); 34 set_bit(BITOPS_88, g_bitmap); 35 return 0; 36 } 37 38 static void __exit test_bitops_unstartup(void) 39 { 40 int bit_set; 41 42 clear_bit(BITOPS_4, g_bitmap); 43 clear_bit(BITOPS_7, g_bitmap); 44 clear_bit(BITOPS_11, g_bitmap); 45 clear_bit(BITOPS_31, g_bitmap); 46 clear_bit(BITOPS_88, g_bitmap); 47 48 bit_set = find_first_bit(g_bitmap, BITOPS_LAST); 49 if (bit_set != BITOPS_LAST) 50 pr_err("ERROR: FOUND SET BIT %d\n", bit_set); 51 52 pr_warn("Unloaded test module\n"); 53 } 54 55 module_init(test_bitops_startup); 56 module_exit(test_bitops_unstartup); 57 58 MODULE_AUTHOR("Jesse Brandeburg <jesse.brandeburg@intel.com>"); 59 MODULE_LICENSE("GPL"); 60 MODULE_DESCRIPTION("Bit testing module"); 61