1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (c) by Jaroslav Kysela <perex@perex.cz> 4 * 5 * Misc memory accessors 6 */ 7 8 #include <linux/export.h> 9 #include <linux/io.h> 10 #include <linux/uaccess.h> 11 #include <sound/core.h> 12 13 /** 14 * copy_to_user_fromio - copy data from mmio-space to user-space 15 * @dst: the destination pointer on user-space 16 * @src: the source pointer on mmio 17 * @count: the data size to copy in bytes 18 * 19 * Copies the data from mmio-space to user-space. 20 * 21 * Return: Zero if successful, or non-zero on failure. 22 */ 23 int copy_to_user_fromio(void __user *dst, const volatile void __iomem *src, size_t count) 24 { 25 #if defined(__i386__) || defined(CONFIG_SPARC32) 26 return copy_to_user(dst, (const void __force*)src, count) ? -EFAULT : 0; 27 #else 28 char buf[256]; 29 while (count) { 30 size_t c = count; 31 if (c > sizeof(buf)) 32 c = sizeof(buf); 33 memcpy_fromio(buf, (void __iomem *)src, c); 34 if (copy_to_user(dst, buf, c)) 35 return -EFAULT; 36 count -= c; 37 dst += c; 38 src += c; 39 } 40 return 0; 41 #endif 42 } 43 EXPORT_SYMBOL(copy_to_user_fromio); 44 45 /** 46 * copy_from_user_toio - copy data from user-space to mmio-space 47 * @dst: the destination pointer on mmio-space 48 * @src: the source pointer on user-space 49 * @count: the data size to copy in bytes 50 * 51 * Copies the data from user-space to mmio-space. 52 * 53 * Return: Zero if successful, or non-zero on failure. 54 */ 55 int copy_from_user_toio(volatile void __iomem *dst, const void __user *src, size_t count) 56 { 57 #if defined(__i386__) || defined(CONFIG_SPARC32) 58 return copy_from_user((void __force *)dst, src, count) ? -EFAULT : 0; 59 #else 60 char buf[256]; 61 while (count) { 62 size_t c = count; 63 if (c > sizeof(buf)) 64 c = sizeof(buf); 65 if (copy_from_user(buf, src, c)) 66 return -EFAULT; 67 memcpy_toio(dst, buf, c); 68 count -= c; 69 dst += c; 70 src += c; 71 } 72 return 0; 73 #endif 74 } 75 EXPORT_SYMBOL(copy_from_user_toio); 76