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Diffstat (limited to 'arch/mips/kernel/process.c')
-rw-r--r--arch/mips/kernel/process.c102
1 files changed, 61 insertions, 41 deletions
diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c
index 5351e1f3950d..c5ff6bfe2825 100644
--- a/arch/mips/kernel/process.c
+++ b/arch/mips/kernel/process.c
@@ -208,13 +208,13 @@ static inline int is_ra_save_ins(union mips_instruction *ip, int *poff)
*
* microMIPS is way more fun...
*/
- if (mm_insn_16bit(ip->halfword[1])) {
+ if (mm_insn_16bit(ip->word >> 16)) {
switch (ip->mm16_r5_format.opcode) {
case mm_swsp16_op:
if (ip->mm16_r5_format.rt != 31)
return 0;
- *poff = ip->mm16_r5_format.simmediate;
+ *poff = ip->mm16_r5_format.imm;
*poff = (*poff << 2) / sizeof(ulong);
return 1;
@@ -287,7 +287,7 @@ static inline int is_jump_ins(union mips_instruction *ip)
*
* microMIPS is kind of more fun...
*/
- if (mm_insn_16bit(ip->halfword[1])) {
+ if (mm_insn_16bit(ip->word >> 16)) {
if ((ip->mm16_r5_format.opcode == mm_pool16c_op &&
(ip->mm16_r5_format.rt & mm_jr16_op) == mm_jr16_op))
return 1;
@@ -313,9 +313,11 @@ static inline int is_jump_ins(union mips_instruction *ip)
#endif
}
-static inline int is_sp_move_ins(union mips_instruction *ip)
+static inline int is_sp_move_ins(union mips_instruction *ip, int *frame_size)
{
#ifdef CONFIG_CPU_MICROMIPS
+ unsigned short tmp;
+
/*
* addiusp -imm
* addius5 sp,-imm
@@ -324,21 +326,40 @@ static inline int is_sp_move_ins(union mips_instruction *ip)
*
* microMIPS is not more fun...
*/
- if (mm_insn_16bit(ip->halfword[1])) {
- return (ip->mm16_r3_format.opcode == mm_pool16d_op &&
- ip->mm16_r3_format.simmediate && mm_addiusp_func) ||
- (ip->mm16_r5_format.opcode == mm_pool16d_op &&
- ip->mm16_r5_format.rt == 29);
+ if (mm_insn_16bit(ip->word >> 16)) {
+ if (ip->mm16_r3_format.opcode == mm_pool16d_op &&
+ ip->mm16_r3_format.simmediate & mm_addiusp_func) {
+ tmp = ip->mm_b0_format.simmediate >> 1;
+ tmp = ((tmp & 0x1ff) ^ 0x100) - 0x100;
+ if ((tmp + 2) < 4) /* 0x0,0x1,0x1fe,0x1ff are special */
+ tmp ^= 0x100;
+ *frame_size = -(signed short)(tmp << 2);
+ return 1;
+ }
+ if (ip->mm16_r5_format.opcode == mm_pool16d_op &&
+ ip->mm16_r5_format.rt == 29) {
+ tmp = ip->mm16_r5_format.imm >> 1;
+ *frame_size = -(signed short)(tmp & 0xf);
+ return 1;
+ }
+ return 0;
}
- return ip->mm_i_format.opcode == mm_addiu32_op &&
- ip->mm_i_format.rt == 29 && ip->mm_i_format.rs == 29;
+ if (ip->mm_i_format.opcode == mm_addiu32_op &&
+ ip->mm_i_format.rt == 29 && ip->mm_i_format.rs == 29) {
+ *frame_size = -ip->i_format.simmediate;
+ return 1;
+ }
#else
/* addiu/daddiu sp,sp,-imm */
if (ip->i_format.rs != 29 || ip->i_format.rt != 29)
return 0;
- if (ip->i_format.opcode == addiu_op || ip->i_format.opcode == daddiu_op)
+
+ if (ip->i_format.opcode == addiu_op ||
+ ip->i_format.opcode == daddiu_op) {
+ *frame_size = -ip->i_format.simmediate;
return 1;
+ }
#endif
return 0;
}
@@ -348,7 +369,9 @@ static int get_frame_info(struct mips_frame_info *info)
bool is_mmips = IS_ENABLED(CONFIG_CPU_MICROMIPS);
union mips_instruction insn, *ip, *ip_end;
const unsigned int max_insns = 128;
+ unsigned int last_insn_size = 0;
unsigned int i;
+ bool saw_jump = false;
info->pc_offset = -1;
info->frame_size = 0;
@@ -359,47 +382,44 @@ static int get_frame_info(struct mips_frame_info *info)
ip_end = (void *)ip + info->func_size;
- for (i = 0; i < max_insns && ip < ip_end; i++, ip++) {
+ for (i = 0; i < max_insns && ip < ip_end; i++) {
+ ip = (void *)ip + last_insn_size;
if (is_mmips && mm_insn_16bit(ip->halfword[0])) {
- insn.halfword[0] = 0;
- insn.halfword[1] = ip->halfword[0];
+ insn.word = ip->halfword[0] << 16;
+ last_insn_size = 2;
} else if (is_mmips) {
- insn.halfword[0] = ip->halfword[1];
- insn.halfword[1] = ip->halfword[0];
+ insn.word = ip->halfword[0] << 16 | ip->halfword[1];
+ last_insn_size = 4;
} else {
insn.word = ip->word;
+ last_insn_size = 4;
}
- if (is_jump_ins(&insn))
- break;
-
if (!info->frame_size) {
- if (is_sp_move_ins(&insn))
- {
-#ifdef CONFIG_CPU_MICROMIPS
- if (mm_insn_16bit(ip->halfword[0]))
- {
- unsigned short tmp;
-
- if (ip->halfword[0] & mm_addiusp_func)
- {
- tmp = (((ip->halfword[0] >> 1) & 0x1ff) << 2);
- info->frame_size = -(signed short)(tmp | ((tmp & 0x100) ? 0xfe00 : 0));
- } else {
- tmp = (ip->halfword[0] >> 1);
- info->frame_size = -(signed short)(tmp & 0xf);
- }
- ip = (void *) &ip->halfword[1];
- ip--;
- } else
-#endif
- info->frame_size = - ip->i_format.simmediate;
- }
+ is_sp_move_ins(&insn, &info->frame_size);
+ continue;
+ } else if (!saw_jump && is_jump_ins(ip)) {
+ /*
+ * If we see a jump instruction, we are finished
+ * with the frame save.
+ *
+ * Some functions can have a shortcut return at
+ * the beginning of the function, so don't start
+ * looking for jump instruction until we see the
+ * frame setup.
+ *
+ * The RA save instruction can get put into the
+ * delay slot of the jump instruction, so look
+ * at the next instruction, too.
+ */
+ saw_jump = true;
continue;
}
if (info->pc_offset == -1 &&
is_ra_save_ins(&insn, &info->pc_offset))
break;
+ if (saw_jump)
+ break;
}
if (info->frame_size && info->pc_offset >= 0) /* nested */
return 0;