arch/sh/include/asm/unaligned-sh4a.h

   1 #ifndef __ASM_SH_UNALIGNED_SH4A_H
   2 #define __ASM_SH_UNALIGNED_SH4A_H
   3
   4 /*
   5  * SH-4A has support for unaligned 32-bit loads, and 32-bit loads only.
   6  * Support for 16 and 64-bit accesses are done through shifting and
   7  * masking relative to the endianness. Unaligned stores are not supported
   8  * by the instruction encoding, so these continue to use the packed
   9  * struct.
  10  *
  11  * The same note as with the movli.l/movco.l pair applies here, as long
  12  * as the load is gauranteed to be inlined, nothing else will hook in to
  13  * r0 and we get the return value for free.
  14  *
  15  * NOTE: Due to the fact we require r0 encoding, care should be taken to
  16  * avoid mixing these heavily with other r0 consumers, such as the atomic
  17  * ops. Failure to adhere to this can result in the compiler running out
  18  * of spill registers and blowing up when building at low optimization
  19  * levels. See http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34777.
  20  */
  21 #include <linux/types.h>
  22 #include <asm/byteorder.h>
  23
  24 static __always_inline u32 __get_unaligned_cpu32(const u8 *p)
  25 {
  26         unsigned long unaligned;
  27
  28         __asm__ __volatile__ (
  29                 "movua.l        @%1, %0\n\t"
  30                  : "=z" (unaligned)
  31                  : "r" (p)
  32         );
  33
  34         return unaligned;
  35 }
  36
  37 struct __una_u16 { u16 x __attribute__((packed)); };
  38 struct __una_u32 { u32 x __attribute__((packed)); };
  39 struct __una_u64 { u64 x __attribute__((packed)); };
  40
  41 static inline u16 __get_unaligned_cpu16(const u8 *p)
  42 {
  43 #ifdef __LITTLE_ENDIAN
  44         return __get_unaligned_cpu32(p) & 0xffff;
  45 #else
  46         return __get_unaligned_cpu32(p) >> 16;
  47 #endif
  48 }
  49
  50 /*
  51  * Even though movua.l supports auto-increment on the read side, it can
  52  * only store to r0 due to instruction encoding constraints, so just let
  53  * the compiler sort it out on its own.
  54  */
  55 static inline u64 __get_unaligned_cpu64(const u8 *p)
  56 {
  57 #ifdef __LITTLE_ENDIAN
  58         return (u64)__get_unaligned_cpu32(p + 4) << 32 |
  59                     __get_unaligned_cpu32(p);
  60 #else
  61         return (u64)__get_unaligned_cpu32(p) << 32 |
  62                     __get_unaligned_cpu32(p + 4);
  63 #endif
  64 }
  65
  66 static inline u16 get_unaligned_le16(const void *p)
  67 {
  68         return le16_to_cpu(__get_unaligned_cpu16(p));
  69 }
  70
  71 static inline u32 get_unaligned_le32(const void *p)
  72 {
  73         return le32_to_cpu(__get_unaligned_cpu32(p));
  74 }
  75
  76 static inline u64 get_unaligned_le64(const void *p)
  77 {
  78         return le64_to_cpu(__get_unaligned_cpu64(p));
  79 }
  80
  81 static inline u16 get_unaligned_be16(const void *p)
  82 {
  83         return be16_to_cpu(__get_unaligned_cpu16(p));
  84 }
  85
  86 static inline u32 get_unaligned_be32(const void *p)
  87 {
  88         return be32_to_cpu(__get_unaligned_cpu32(p));
  89 }
  90
  91 static inline u64 get_unaligned_be64(const void *p)
  92 {
  93         return be64_to_cpu(__get_unaligned_cpu64(p));
  94 }
  95
  96 static inline void __put_le16_noalign(u8 *p, u16 val)
  97 {
  98         *p++ = val;
  99         *p++ = val >> 8;
 100 }
 101
 102 static inline void __put_le32_noalign(u8 *p, u32 val)
 103 {
 104         __put_le16_noalign(p, val);
 105         __put_le16_noalign(p + 2, val >> 16);
 106 }
 107
 108 static inline void __put_le64_noalign(u8 *p, u64 val)
 109 {
 110         __put_le32_noalign(p, val);
 111         __put_le32_noalign(p + 4, val >> 32);
 112 }
 113
 114 static inline void __put_be16_noalign(u8 *p, u16 val)
 115 {
 116         *p++ = val >> 8;
 117         *p++ = val;
 118 }
 119
 120 static inline void __put_be32_noalign(u8 *p, u32 val)
 121 {
 122         __put_be16_noalign(p, val >> 16);
 123         __put_be16_noalign(p + 2, val);
 124 }
 125
 126 static inline void __put_be64_noalign(u8 *p, u64 val)
 127 {
 128         __put_be32_noalign(p, val >> 32);
 129         __put_be32_noalign(p + 4, val);
 130 }
 131
 132 static inline void put_unaligned_le16(u16 val, void *p)
 133 {
 134 #ifdef __LITTLE_ENDIAN
 135         ((struct __una_u16 *)p)->x = val;
 136 #else
 137         __put_le16_noalign(p, val);
 138 #endif
 139 }
 140
 141 static inline void put_unaligned_le32(u32 val, void *p)
 142 {
 143 #ifdef __LITTLE_ENDIAN
 144         ((struct __una_u32 *)p)->x = val;
 145 #else
 146         __put_le32_noalign(p, val);
 147 #endif
 148 }
 149
 150 static inline void put_unaligned_le64(u64 val, void *p)
 151 {
 152 #ifdef __LITTLE_ENDIAN
 153         ((struct __una_u64 *)p)->x = val;
 154 #else
 155         __put_le64_noalign(p, val);
 156 #endif
 157 }
 158
 159 static inline void put_unaligned_be16(u16 val, void *p)
 160 {
 161 #ifdef __BIG_ENDIAN
 162         ((struct __una_u16 *)p)->x = val;
 163 #else
 164         __put_be16_noalign(p, val);
 165 #endif
 166 }
 167
 168 static inline void put_unaligned_be32(u32 val, void *p)
 169 {
 170 #ifdef __BIG_ENDIAN
 171         ((struct __una_u32 *)p)->x = val;
 172 #else
 173         __put_be32_noalign(p, val);
 174 #endif
 175 }
 176
 177 static inline void put_unaligned_be64(u64 val, void *p)
 178 {
 179 #ifdef __BIG_ENDIAN
 180         ((struct __una_u64 *)p)->x = val;
 181 #else
 182         __put_be64_noalign(p, val);
 183 #endif
 184 }
 185
 186 /*
 187  * Cause a link-time error if we try an unaligned access other than
 188  * 1,2,4 or 8 bytes long
 189  */
 190 extern void __bad_unaligned_access_size(void);
 191
 192 #define __get_unaligned_le(ptr) ((__force typeof(*(ptr)))({                     \
 193         __builtin_choose_expr(sizeof(*(ptr)) == 1, *(ptr),                      \
 194         __builtin_choose_expr(sizeof(*(ptr)) == 2, get_unaligned_le16((ptr)),   \
 195         __builtin_choose_expr(sizeof(*(ptr)) == 4, get_unaligned_le32((ptr)),   \
 196         __builtin_choose_expr(sizeof(*(ptr)) == 8, get_unaligned_le64((ptr)),   \
 197         __bad_unaligned_access_size()))));                                      \
 198         }))
 199
 200 #define __get_unaligned_be(ptr) ((__force typeof(*(ptr)))({                     \
 201         __builtin_choose_expr(sizeof(*(ptr)) == 1, *(ptr),                      \
 202         __builtin_choose_expr(sizeof(*(ptr)) == 2, get_unaligned_be16((ptr)),   \
 203         __builtin_choose_expr(sizeof(*(ptr)) == 4, get_unaligned_be32((ptr)),   \
 204         __builtin_choose_expr(sizeof(*(ptr)) == 8, get_unaligned_be64((ptr)),   \
 205         __bad_unaligned_access_size()))));                                      \
 206         }))
 207
 208 #define __put_unaligned_le(val, ptr) ({                                 \
 209         void *__gu_p = (ptr);                                           \
 210         switch (sizeof(*(ptr))) {                                       \
 211         case 1:                                                         \
 212                 *(u8 *)__gu_p = (__force u8)(val);                      \
 213                 break;                                                  \
 214         case 2:                                                         \
 215                 put_unaligned_le16((__force u16)(val), __gu_p);         \
 216                 break;                                                  \
 217         case 4:                                                         \
 218                 put_unaligned_le32((__force u32)(val), __gu_p);         \
 219                 break;                                                  \
 220         case 8:                                                         \
 221                 put_unaligned_le64((__force u64)(val), __gu_p);         \
 222                 break;                                                  \
 223         default:                                                        \
 224                 __bad_unaligned_access_size();                          \
 225                 break;                                                  \
 226         }                                                               \
 227         (void)0; })
 228
 229 #define __put_unaligned_be(val, ptr) ({                                 \
 230         void *__gu_p = (ptr);                                           \
 231         switch (sizeof(*(ptr))) {                                       \
 232         case 1:                                                         \
 233                 *(u8 *)__gu_p = (__force u8)(val);                      \
 234                 break;                                                  \
 235         case 2:                                                         \
 236                 put_unaligned_be16((__force u16)(val), __gu_p);         \
 237                 break;                                                  \
 238         case 4:                                                         \
 239                 put_unaligned_be32((__force u32)(val), __gu_p);         \
 240                 break;                                                  \
 241         case 8:                                                         \
 242                 put_unaligned_be64((__force u64)(val), __gu_p);         \
 243                 break;                                                  \
 244         default:                                                        \
 245                 __bad_unaligned_access_size();                          \
 246                 break;                                                  \
 247         }                                                               \
 248         (void)0; })
 249
 250 #ifdef __LITTLE_ENDIAN
 251 # define get_unaligned __get_unaligned_le
 252 # define put_unaligned __put_unaligned_le
 253 #else
 254 # define get_unaligned __get_unaligned_be
 255 # define put_unaligned __put_unaligned_be
 256 #endif
 257
 258 #endif /* __ASM_SH_UNALIGNED_SH4A_H */