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Diffstat (limited to 'kernel/arch/blackfin/include/asm/uaccess.h')
| -rw-r--r-- | kernel/arch/blackfin/include/asm/uaccess.h | 275 |
1 files changed, 275 insertions, 0 deletions
diff --git a/kernel/arch/blackfin/include/asm/uaccess.h b/kernel/arch/blackfin/include/asm/uaccess.h new file mode 100644 index 000000000..90612a7f2 --- /dev/null +++ b/kernel/arch/blackfin/include/asm/uaccess.h @@ -0,0 +1,275 @@ +/* + * Copyright 2004-2009 Analog Devices Inc. + * + * Licensed under the GPL-2 or later. + * + * Based on: include/asm-m68knommu/uaccess.h + */ + +#ifndef __BLACKFIN_UACCESS_H +#define __BLACKFIN_UACCESS_H + +/* + * User space memory access functions + */ +#include <linux/sched.h> +#include <linux/mm.h> +#include <linux/string.h> + +#include <asm/segment.h> +#include <asm/sections.h> + +#define get_ds() (KERNEL_DS) +#define get_fs() (current_thread_info()->addr_limit) + +static inline void set_fs(mm_segment_t fs) +{ + current_thread_info()->addr_limit = fs; +} + +#define segment_eq(a, b) ((a) == (b)) + +#define VERIFY_READ 0 +#define VERIFY_WRITE 1 + +#define access_ok(type, addr, size) _access_ok((unsigned long)(addr), (size)) + +/* + * The fs value determines whether argument validity checking should be + * performed or not. If get_fs() == USER_DS, checking is performed, with + * get_fs() == KERNEL_DS, checking is bypassed. + */ + +#ifndef CONFIG_ACCESS_CHECK +static inline int _access_ok(unsigned long addr, unsigned long size) { return 1; } +#else +extern int _access_ok(unsigned long addr, unsigned long size); +#endif + +/* + * 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, fixup; +}; + +/* + * These are the main single-value transfer routines. They automatically + * use the right size if we just have the right pointer type. + */ + +#define put_user(x, p) \ + ({ \ + int _err = 0; \ + typeof(*(p)) _x = (x); \ + typeof(*(p)) __user *_p = (p); \ + if (!access_ok(VERIFY_WRITE, _p, sizeof(*(_p)))) {\ + _err = -EFAULT; \ + } \ + else { \ + switch (sizeof (*(_p))) { \ + case 1: \ + __put_user_asm(_x, _p, B); \ + break; \ + case 2: \ + __put_user_asm(_x, _p, W); \ + break; \ + case 4: \ + __put_user_asm(_x, _p, ); \ + break; \ + case 8: { \ + long _xl, _xh; \ + _xl = ((__force long *)&_x)[0]; \ + _xh = ((__force long *)&_x)[1]; \ + __put_user_asm(_xl, ((__force long __user *)_p)+0, );\ + __put_user_asm(_xh, ((__force long __user *)_p)+1, );\ + } break; \ + default: \ + _err = __put_user_bad(); \ + break; \ + } \ + } \ + _err; \ + }) + +#define __put_user(x, p) put_user(x, p) +static inline int bad_user_access_length(void) +{ + panic("bad_user_access_length"); + return -1; +} + +#define __put_user_bad() (printk(KERN_INFO "put_user_bad %s:%d %s\n",\ + __FILE__, __LINE__, __func__),\ + bad_user_access_length(), (-EFAULT)) + +/* + * Tell gcc we read from memory instead of writing: this is because + * we do not write to any memory gcc knows about, so there are no + * aliasing issues. + */ + +#define __ptr(x) ((unsigned long __force *)(x)) + +#define __put_user_asm(x, p, bhw) \ + __asm__ (#bhw"[%1] = %0;\n\t" \ + : /* no outputs */ \ + :"d" (x), "a" (__ptr(p)) : "memory") + +#define get_user(x, ptr) \ +({ \ + int _err = 0; \ + unsigned long _val = 0; \ + const typeof(*(ptr)) __user *_p = (ptr); \ + const size_t ptr_size = sizeof(*(_p)); \ + if (likely(access_ok(VERIFY_READ, _p, ptr_size))) { \ + BUILD_BUG_ON(ptr_size >= 8); \ + switch (ptr_size) { \ + case 1: \ + __get_user_asm(_val, _p, B, (Z)); \ + break; \ + case 2: \ + __get_user_asm(_val, _p, W, (Z)); \ + break; \ + case 4: \ + __get_user_asm(_val, _p, , ); \ + break; \ + } \ + } else \ + _err = -EFAULT; \ + x = (__force typeof(*(ptr)))_val; \ + _err; \ +}) + +#define __get_user(x, p) get_user(x, p) + +#define __get_user_bad() (bad_user_access_length(), (-EFAULT)) + +#define __get_user_asm(x, ptr, bhw, option) \ +({ \ + __asm__ __volatile__ ( \ + "%0 =" #bhw "[%1]" #option ";" \ + : "=d" (x) \ + : "a" (__ptr(ptr))); \ +}) + +#define __copy_from_user(to, from, n) copy_from_user(to, from, n) +#define __copy_to_user(to, from, n) copy_to_user(to, from, n) +#define __copy_to_user_inatomic __copy_to_user +#define __copy_from_user_inatomic __copy_from_user + +#define copy_to_user_ret(to, from, n, retval) ({ if (copy_to_user(to, from, n))\ + return retval; }) + +#define copy_from_user_ret(to, from, n, retval) ({ if (copy_from_user(to, from, n))\ + return retval; }) + +static inline unsigned long __must_check +copy_from_user(void *to, const void __user *from, unsigned long n) +{ + if (access_ok(VERIFY_READ, from, n)) + memcpy(to, (const void __force *)from, n); + else + return n; + return 0; +} + +static inline unsigned long __must_check +copy_to_user(void __user *to, const void *from, unsigned long n) +{ + if (access_ok(VERIFY_WRITE, to, n)) + memcpy((void __force *)to, from, n); + else + return n; + SSYNC(); + return 0; +} + +/* + * Copy a null terminated string from userspace. + */ + +static inline long __must_check +strncpy_from_user(char *dst, const char __user *src, long count) +{ + char *tmp; + if (!access_ok(VERIFY_READ, src, 1)) + return -EFAULT; + strncpy(dst, (const char __force *)src, count); + for (tmp = dst; *tmp && count > 0; tmp++, count--) ; + return (tmp - dst); +} + +/* + * Get the size of a string in user space. + * src: The string to measure + * n: The maximum valid length + * + * Get the size of a NUL-terminated string in user space. + * + * Returns the size of the string INCLUDING the terminating NUL. + * On exception, returns 0. + * If the string is too long, returns a value greater than n. + */ +static inline long __must_check strnlen_user(const char __user *src, long n) +{ + if (!access_ok(VERIFY_READ, src, 1)) + return 0; + return strnlen((const char __force *)src, n) + 1; +} + +static inline long __must_check strlen_user(const char __user *src) +{ + if (!access_ok(VERIFY_READ, src, 1)) + return 0; + return strlen((const char __force *)src) + 1; +} + +/* + * Zero Userspace + */ + +static inline unsigned long __must_check +__clear_user(void __user *to, unsigned long n) +{ + if (!access_ok(VERIFY_WRITE, to, n)) + return n; + memset((void __force *)to, 0, n); + return 0; +} + +#define clear_user(to, n) __clear_user(to, n) + +/* How to interpret these return values: + * CORE: can be accessed by core load or dma memcpy + * CORE_ONLY: can only be accessed by core load + * DMA: can only be accessed by dma memcpy + * IDMA: can only be accessed by interprocessor dma memcpy (BF561) + * ITEST: can be accessed by isram memcpy or dma memcpy + */ +enum { + BFIN_MEM_ACCESS_CORE = 0, + BFIN_MEM_ACCESS_CORE_ONLY, + BFIN_MEM_ACCESS_DMA, + BFIN_MEM_ACCESS_IDMA, + BFIN_MEM_ACCESS_ITEST, +}; +/** + * bfin_mem_access_type() - what kind of memory access is required + * @addr: the address to check + * @size: number of bytes needed + * @return: <0 is error, >=0 is BFIN_MEM_ACCESS_xxx enum (see above) + */ +int bfin_mem_access_type(unsigned long addr, unsigned long size); + +#endif /* _BLACKFIN_UACCESS_H */ |