/* * 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> #ifdef CONFIG_ACCESS_CHECK # include <asm/bfin-global.h> #endif #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)) static inline int is_in_rom(unsigned long addr) { /* * What we are really trying to do is determine if addr is * in an allocated kernel memory region. If not then assume * we cannot free it or otherwise de-allocate it. Ideally * we could restrict this to really being in a ROM or flash, * but that would need to be done on a board by board basis, * not globally. */ if ((addr < _ramstart) || (addr >= _ramend)) return (1); /* Default case, not in ROM */ return (0); } /* * 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)) *_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 = ((long *)&_x)[0]; \ _xh = ((long *)&_x)[1]; \ __put_user_asm(_xl, ((long *)_p)+0, ); \ __put_user_asm(_xh, ((long *)_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 *)(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 = (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, from, n); else return n; return 0; } static inline unsigned long __must_check copy_to_user(void *to, const void __user *from, unsigned long n) { if (access_ok(VERIFY_WRITE, to, n)) memcpy(to, from, n); else return n; return 0; } /* * Copy a null terminated string from userspace. */ static inline long __must_check strncpy_from_user(char *dst, const char *src, long count) { char *tmp; if (!access_ok(VERIFY_READ, src, 1)) return -EFAULT; strncpy(dst, 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 *src, long n) { if (!access_ok(VERIFY_READ, src, 1)) return 0; return strnlen(src, n) + 1; } static inline long __must_check strlen_user(const char *src) { if (!access_ok(VERIFY_READ, src, 1)) return 0; return strlen(src) + 1; } /* * Zero Userspace */ static inline unsigned long __must_check __clear_user(void *to, unsigned long n) { if (!access_ok(VERIFY_WRITE, to, n)) return n; memset(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 */