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Diffstat (limited to 'arch/nios2/include/asm/uaccess.h')
| -rw-r--r-- | arch/nios2/include/asm/uaccess.h | 231 |
1 files changed, 231 insertions, 0 deletions
diff --git a/arch/nios2/include/asm/uaccess.h b/arch/nios2/include/asm/uaccess.h new file mode 100644 index 000000000000..acedc0a2860e --- /dev/null +++ b/arch/nios2/include/asm/uaccess.h @@ -0,0 +1,231 @@ +/* + * User space memory access functions for Nios II + * + * Copyright (C) 2010-2011, Tobias Klauser <tklauser@distanz.ch> + * Copyright (C) 2009, Wind River Systems Inc + * Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ + +#ifndef _ASM_NIOS2_UACCESS_H +#define _ASM_NIOS2_UACCESS_H + +#include <linux/errno.h> +#include <linux/thread_info.h> +#include <linux/string.h> + +#include <asm/page.h> + +#define VERIFY_READ 0 +#define VERIFY_WRITE 1 + +/* + * The exception table consists of pairs of addresses: the first is the + * address of an instruction that is allowed to fault, and the second is + * the address at which the program should continue. No registers are + * modified, so it is entirely up to the continuation code to figure out + * what to do. + * + * All the routines below use bits of fixup code that are out of line + * with the main instruction path. This means when everything is well, + * we don't even have to jump over them. Further, they do not intrude + * on our cache or tlb entries. + */ +struct exception_table_entry { + unsigned long insn; + unsigned long fixup; +}; + +extern int fixup_exception(struct pt_regs *regs); + +/* + * Segment stuff + */ +#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) +#define USER_DS MAKE_MM_SEG(0x80000000UL) +#define KERNEL_DS MAKE_MM_SEG(0) + +#define get_ds() (KERNEL_DS) + +#define get_fs() (current_thread_info()->addr_limit) +#define set_fs(seg) (current_thread_info()->addr_limit = (seg)) + +#define segment_eq(a, b) ((a).seg == (b).seg) + +#define __access_ok(addr, len) \ + (((signed long)(((long)get_fs().seg) & \ + ((long)(addr) | (((long)(addr)) + (len)) | (len)))) == 0) + +#define access_ok(type, addr, len) \ + likely(__access_ok((unsigned long)(addr), (unsigned long)(len))) + +# define __EX_TABLE_SECTION ".section __ex_table,\"a\"\n" + +/* + * Zero Userspace + */ + +static inline unsigned long __must_check __clear_user(void __user *to, + unsigned long n) +{ + __asm__ __volatile__ ( + "1: stb zero, 0(%1)\n" + " addi %0, %0, -1\n" + " addi %1, %1, 1\n" + " bne %0, zero, 1b\n" + "2:\n" + __EX_TABLE_SECTION + ".word 1b, 2b\n" + ".previous\n" + : "=r" (n), "=r" (to) + : "0" (n), "1" (to) + ); + + return n; +} + +static inline unsigned long __must_check clear_user(void __user *to, + unsigned long n) +{ + if (!access_ok(VERIFY_WRITE, to, n)) + return n; + return __clear_user(to, n); +} + +extern long __copy_from_user(void *to, const void __user *from, + unsigned long n); +extern long __copy_to_user(void __user *to, const void *from, unsigned long n); + +static inline long copy_from_user(void *to, const void __user *from, + unsigned long n) +{ + if (!access_ok(VERIFY_READ, from, n)) + return n; + return __copy_from_user(to, from, n); +} + +static inline long copy_to_user(void __user *to, const void *from, + unsigned long n) +{ + if (!access_ok(VERIFY_WRITE, to, n)) + return n; + return __copy_to_user(to, from, n); +} + +extern long strncpy_from_user(char *__to, const char __user *__from, + long __len); +extern long strnlen_user(const char __user *s, long n); + +#define __copy_from_user_inatomic __copy_from_user +#define __copy_to_user_inatomic __copy_to_user + +/* Optimized macros */ +#define __get_user_asm(val, insn, addr, err) \ +{ \ + __asm__ __volatile__( \ + " movi %0, %3\n" \ + "1: " insn " %1, 0(%2)\n" \ + " movi %0, 0\n" \ + "2:\n" \ + " .section __ex_table,\"a\"\n" \ + " .word 1b, 2b\n" \ + " .previous" \ + : "=&r" (err), "=r" (val) \ + : "r" (addr), "i" (-EFAULT)); \ +} + +#define __get_user_unknown(val, size, ptr, err) do { \ + err = 0; \ + if (copy_from_user(&(val), ptr, size)) { \ + err = -EFAULT; \ + } \ + } while (0) + +#define __get_user_common(val, size, ptr, err) \ +do { \ + switch (size) { \ + case 1: \ + __get_user_asm(val, "ldbu", ptr, err); \ + break; \ + case 2: \ + __get_user_asm(val, "ldhu", ptr, err); \ + break; \ + case 4: \ + __get_user_asm(val, "ldw", ptr, err); \ + break; \ + default: \ + __get_user_unknown(val, size, ptr, err); \ + break; \ + } \ +} while (0) + +#define __get_user(x, ptr) \ + ({ \ + long __gu_err = -EFAULT; \ + const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \ + unsigned long __gu_val; \ + __get_user_common(__gu_val, sizeof(*(ptr)), __gu_ptr, __gu_err);\ + (x) = (__typeof__(x))__gu_val; \ + __gu_err; \ + }) + +#define get_user(x, ptr) \ +({ \ + long __gu_err = -EFAULT; \ + const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \ + unsigned long __gu_val = 0; \ + if (access_ok(VERIFY_READ, __gu_ptr, sizeof(*__gu_ptr))) \ + __get_user_common(__gu_val, sizeof(*__gu_ptr), \ + __gu_ptr, __gu_err); \ + (x) = (__typeof__(x))__gu_val; \ + __gu_err; \ +}) + +#define __put_user_asm(val, insn, ptr, err) \ +{ \ + __asm__ __volatile__( \ + " movi %0, %3\n" \ + "1: " insn " %1, 0(%2)\n" \ + " movi %0, 0\n" \ + "2:\n" \ + " .section __ex_table,\"a\"\n" \ + " .word 1b, 2b\n" \ + " .previous\n" \ + : "=&r" (err) \ + : "r" (val), "r" (ptr), "i" (-EFAULT)); \ +} + +#define put_user(x, ptr) \ +({ \ + long __pu_err = -EFAULT; \ + __typeof__(*(ptr)) __user *__pu_ptr = (ptr); \ + __typeof__(*(ptr)) __pu_val = (__typeof(*ptr))(x); \ + if (access_ok(VERIFY_WRITE, __pu_ptr, sizeof(*__pu_ptr))) { \ + switch (sizeof(*__pu_ptr)) { \ + case 1: \ + __put_user_asm(__pu_val, "stb", __pu_ptr, __pu_err); \ + break; \ + case 2: \ + __put_user_asm(__pu_val, "sth", __pu_ptr, __pu_err); \ + break; \ + case 4: \ + __put_user_asm(__pu_val, "stw", __pu_ptr, __pu_err); \ + break; \ + default: \ + /* XXX: This looks wrong... */ \ + __pu_err = 0; \ + if (copy_to_user(__pu_ptr, &(__pu_val), \ + sizeof(*__pu_ptr))) \ + __pu_err = -EFAULT; \ + break; \ + } \ + } \ + __pu_err; \ +}) + +#define __put_user(x, ptr) put_user(x, ptr) + +#endif /* _ASM_NIOS2_UACCESS_H */ |