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authorLeonid Yegoshin <Leonid.Yegoshin@imgtec.com>2013-03-25 13:18:07 -0500
committerRalf Baechle <ralf@linux-mips.org>2013-05-09 17:55:19 +0200
commit34c2f668d0f6b2ca1c076d8170d6cd4f2235a9d4 (patch)
tree9acdf8f14f17afde3c1f7d4abee55b0c8d3ca0ac /arch/mips/kernel/process.c
parentfb6883e5809c08e43de23581759af4570ca91b0f (diff)
MIPS: microMIPS: Add unaligned access support.
Add logic needed to handle unaligned accesses in microMIPS mode. Signed-off-by: Steven J. Hill <Steven.Hill@imgtec.com> Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Diffstat (limited to 'arch/mips/kernel/process.c')
-rw-r--r--arch/mips/kernel/process.c101
1 files changed, 101 insertions, 0 deletions
diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c
index 3be4405c2d14..ef533760d2c8 100644
--- a/arch/mips/kernel/process.c
+++ b/arch/mips/kernel/process.c
@@ -7,6 +7,7 @@
* Copyright (C) 2005, 2006 by Ralf Baechle (ralf@linux-mips.org)
* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
* Copyright (C) 2004 Thiemo Seufer
+ * Copyright (C) 2013 Imagination Technologies Ltd.
*/
#include <linux/errno.h>
#include <linux/sched.h>
@@ -243,34 +244,115 @@ struct mips_frame_info {
static inline int is_ra_save_ins(union mips_instruction *ip)
{
+#ifdef CONFIG_CPU_MICROMIPS
+ union mips_instruction mmi;
+
+ /*
+ * swsp ra,offset
+ * swm16 reglist,offset(sp)
+ * swm32 reglist,offset(sp)
+ * sw32 ra,offset(sp)
+ * jradiussp - NOT SUPPORTED
+ *
+ * microMIPS is way more fun...
+ */
+ if (mm_insn_16bit(ip->halfword[0])) {
+ mmi.word = (ip->halfword[0] << 16);
+ return ((mmi.mm16_r5_format.opcode == mm_swsp16_op &&
+ mmi.mm16_r5_format.rt == 31) ||
+ (mmi.mm16_m_format.opcode == mm_pool16c_op &&
+ mmi.mm16_m_format.func == mm_swm16_op));
+ }
+ else {
+ mmi.halfword[0] = ip->halfword[1];
+ mmi.halfword[1] = ip->halfword[0];
+ return ((mmi.mm_m_format.opcode == mm_pool32b_op &&
+ mmi.mm_m_format.rd > 9 &&
+ mmi.mm_m_format.base == 29 &&
+ mmi.mm_m_format.func == mm_swm32_func) ||
+ (mmi.i_format.opcode == mm_sw32_op &&
+ mmi.i_format.rs == 29 &&
+ mmi.i_format.rt == 31));
+ }
+#else
/* sw / sd $ra, offset($sp) */
return (ip->i_format.opcode == sw_op || ip->i_format.opcode == sd_op) &&
ip->i_format.rs == 29 &&
ip->i_format.rt == 31;
+#endif
}
static inline int is_jal_jalr_jr_ins(union mips_instruction *ip)
{
+#ifdef CONFIG_CPU_MICROMIPS
+ /*
+ * jr16,jrc,jalr16,jalr16
+ * jal
+ * jalr/jr,jalr.hb/jr.hb,jalrs,jalrs.hb
+ * jraddiusp - NOT SUPPORTED
+ *
+ * microMIPS is kind of more fun...
+ */
+ union mips_instruction mmi;
+
+ mmi.word = (ip->halfword[0] << 16);
+
+ if ((mmi.mm16_r5_format.opcode == mm_pool16c_op &&
+ (mmi.mm16_r5_format.rt & mm_jr16_op) == mm_jr16_op) ||
+ ip->j_format.opcode == mm_jal32_op)
+ return 1;
+ if (ip->r_format.opcode != mm_pool32a_op ||
+ ip->r_format.func != mm_pool32axf_op)
+ return 0;
+ return (((ip->u_format.uimmediate >> 6) & mm_jalr_op) == mm_jalr_op);
+#else
if (ip->j_format.opcode == jal_op)
return 1;
if (ip->r_format.opcode != spec_op)
return 0;
return ip->r_format.func == jalr_op || ip->r_format.func == jr_op;
+#endif
}
static inline int is_sp_move_ins(union mips_instruction *ip)
{
+#ifdef CONFIG_CPU_MICROMIPS
+ /*
+ * addiusp -imm
+ * addius5 sp,-imm
+ * addiu32 sp,sp,-imm
+ * jradiussp - NOT SUPPORTED
+ *
+ * microMIPS is not more fun...
+ */
+ if (mm_insn_16bit(ip->halfword[0])) {
+ union mips_instruction mmi;
+
+ mmi.word = (ip->halfword[0] << 16);
+ return ((mmi.mm16_r3_format.opcode == mm_pool16d_op &&
+ mmi.mm16_r3_format.simmediate && mm_addiusp_func) ||
+ (mmi.mm16_r5_format.opcode == mm_pool16d_op &&
+ mmi.mm16_r5_format.rt == 29));
+ }
+ return (ip->mm_i_format.opcode == mm_addiu32_op &&
+ ip->mm_i_format.rt == 29 && ip->mm_i_format.rs == 29);
+#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)
return 1;
+#endif
return 0;
}
static int get_frame_info(struct mips_frame_info *info)
{
+#ifdef CONFIG_CPU_MICROMIPS
+ union mips_instruction *ip = (void *) (((char *) info->func) - 1);
+#else
union mips_instruction *ip = info->func;
+#endif
unsigned max_insns = info->func_size / sizeof(union mips_instruction);
unsigned i;
@@ -290,7 +372,26 @@ static int get_frame_info(struct mips_frame_info *info)
break;
if (!info->frame_size) {
if (is_sp_move_ins(ip))
+ {
+#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;
+ }
continue;
}
if (info->pc_offset == -1 && is_ra_save_ins(ip)) {