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authorMagnus Damm <magnus.damm@gmail.com>2008-02-06 10:02:50 -0500
committerPaul Mundt <lethal@linux-sh.org>2008-02-14 00:22:07 -0500
commit86c0179c9307bd600a96a44d623814c33bdbe0f0 (patch)
tree6651026da498831b60c4c3694781b8ac9d44facf /arch/sh
parent1cfb629cfa4a8d9b65c0f60c65ec731bde82d60c (diff)
sh: break out unaligned sign extension code
Break out the sign extension code since it's used in multiple places. Signed-off-by: Magnus Damm <damm@igel.co.jp> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Diffstat (limited to 'arch/sh')
-rw-r--r--arch/sh/kernel/traps_32.c68
1 files changed, 23 insertions, 45 deletions
diff --git a/arch/sh/kernel/traps_32.c b/arch/sh/kernel/traps_32.c
index 2e58f7a6b746..7154a7b2135b 100644
--- a/arch/sh/kernel/traps_32.c
+++ b/arch/sh/kernel/traps_32.c
@@ -147,6 +147,21 @@ static int die_if_no_fixup(const char * str, struct pt_regs * regs, long err)
147 return -EFAULT; 147 return -EFAULT;
148} 148}
149 149
150static inline void sign_extend(unsigned int count, unsigned char *dst)
151{
152#ifdef __LITTLE_ENDIAN__
153 if ((count == 2) && dst[1] & 0x80) {
154 dst[2] = 0xff;
155 dst[3] = 0xff;
156 }
157#else
158 if ((count == 2) && dst[2] & 0x80) {
159 dst[0] = 0xff;
160 dst[1] = 0xff;
161 }
162#endif
163}
164
150/* 165/*
151 * handle an instruction that does an unaligned memory access by emulating the 166 * handle an instruction that does an unaligned memory access by emulating the
152 * desired behaviour 167 * desired behaviour
@@ -178,25 +193,13 @@ static int handle_unaligned_ins(u16 instruction, struct pt_regs *regs)
178 dst = (unsigned char*) rn; 193 dst = (unsigned char*) rn;
179 *(unsigned long*)dst = 0; 194 *(unsigned long*)dst = 0;
180 195
181#ifdef __LITTLE_ENDIAN__ 196#if !defined(__LITTLE_ENDIAN__)
182 if (copy_from_user(dst, src, count))
183 goto fetch_fault;
184
185 if ((count == 2) && dst[1] & 0x80) {
186 dst[2] = 0xff;
187 dst[3] = 0xff;
188 }
189#else
190 dst += 4-count; 197 dst += 4-count;
191 198#endif
192 if (__copy_user(dst, src, count)) 199 if (copy_from_user(dst, src, count))
193 goto fetch_fault; 200 goto fetch_fault;
194 201
195 if ((count == 2) && dst[2] & 0x80) { 202 sign_extend(count, dst);
196 dst[0] = 0xff;
197 dst[1] = 0xff;
198 }
199#endif
200 } else { 203 } else {
201 /* to memory */ 204 /* to memory */
202 src = (unsigned char*) rm; 205 src = (unsigned char*) rm;
@@ -253,25 +256,12 @@ static int handle_unaligned_ins(u16 instruction, struct pt_regs *regs)
253 dst = (unsigned char*) rn; 256 dst = (unsigned char*) rn;
254 *(unsigned long*)dst = 0; 257 *(unsigned long*)dst = 0;
255 258
256#ifdef __LITTLE_ENDIAN__ 259#if !defined(__LITTLE_ENDIAN__)
257 if (copy_from_user(dst, src, count))
258 goto fetch_fault;
259
260 if ((count == 2) && dst[1] & 0x80) {
261 dst[2] = 0xff;
262 dst[3] = 0xff;
263 }
264#else
265 dst += 4-count; 260 dst += 4-count;
266 261#endif
267 if (copy_from_user(dst, src, count)) 262 if (copy_from_user(dst, src, count))
268 goto fetch_fault; 263 goto fetch_fault;
269 264 sign_extend(count, dst);
270 if ((count == 2) && dst[2] & 0x80) {
271 dst[0] = 0xff;
272 dst[1] = 0xff;
273 }
274#endif
275 ret = 0; 265 ret = 0;
276 break; 266 break;
277 267
@@ -299,21 +289,9 @@ static int handle_unaligned_ins(u16 instruction, struct pt_regs *regs)
299#if !defined(__LITTLE_ENDIAN__) 289#if !defined(__LITTLE_ENDIAN__)
300 dst += 2; 290 dst += 2;
301#endif 291#endif
302
303 if (copy_from_user(dst, src, 2)) 292 if (copy_from_user(dst, src, 2))
304 goto fetch_fault; 293 goto fetch_fault;
305 294 sign_extend(2, dst);
306#ifdef __LITTLE_ENDIAN__
307 if (dst[1] & 0x80) {
308 dst[2] = 0xff;
309 dst[3] = 0xff;
310 }
311#else
312 if (dst[2] & 0x80) {
313 dst[0] = 0xff;
314 dst[1] = 0xff;
315 }
316#endif
317 ret = 0; 295 ret = 0;
318 break; 296 break;
319 } 297 }