powerpc: Emulate icbi, mcrf and conditional-trap instructions

This extends the instruction emulation done by analyse_instr() and
emulate_step() to handle a few more instructions that are found in
the kernel.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 60 insertions, 0 deletions

diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index 3726a03179ab..209a506f8517 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -600,6 +600,23 @@ static void __kprobes do_cmp_unsigned(struct pt_regs *regs, unsigned long v1,
         regs->ccr = (regs->ccr & ~(0xf << shift)) | (crval << shift);
 }
 
+static int __kprobes trap_compare(long v1, long v2)
+{
+        int ret = 0;
+
+        if (v1 < v2)
+                ret |= 0x10;
+        else if (v1 > v2)
+                ret |= 0x08;
+        else
+                ret |= 0x04;
+        if ((unsigned long)v1 < (unsigned long)v2)
+                ret |= 0x02;
+        else if ((unsigned long)v1 > (unsigned long)v2)
+                ret |= 0x01;
+        return ret;
+}
+
 /*
  * Elements of 32-bit rotate and mask instructions.
  */
@@ -669,6 +686,13 @@ int __kprobes analyse_instr(struct instruction_op *op, struct pt_regs *regs,
                 return 1;
         case 19:
                 switch ((instr >> 1) & 0x3ff) {
+                case 0:         /* mcrf */
+                        rd = (instr >> 21) & 0x1c;
+                        ra = (instr >> 16) & 0x1c;
+                        val = (regs->ccr >> ra) & 0xf;
+                        regs->ccr = (regs->ccr & ~(0xfUL << rd)) | (val << rd);
+                        goto instr_done;
+
                 case 16:        /* bclr */
                 case 528:       /* bcctr */
                         op->type = BRANCH;
@@ -745,6 +769,17 @@ int __kprobes analyse_instr(struct instruction_op *op, struct pt_regs *regs,
         rb = (instr >> 11) & 0x1f;
 
         switch (opcode) {
+#ifdef __powerpc64__
+        case 2:         /* tdi */
+                if (rd & trap_compare(regs->gpr[ra], (short) instr))
+                        goto trap;
+                goto instr_done;
+#endif
+        case 3:         /* twi */
+                if (rd & trap_compare((int)regs->gpr[ra], (short) instr))
+                        goto trap;
+                goto instr_done;
+
         case 7:         /* mulli */
                 regs->gpr[rd] = regs->gpr[ra] * (short) instr;
                 goto instr_done;
@@ -893,6 +928,18 @@ int __kprobes analyse_instr(struct instruction_op *op, struct pt_regs *regs,
 
         case 31:
                 switch ((instr >> 1) & 0x3ff) {
+                case 4:         /* tw */
+                        if (rd == 0x1f ||
+                            (rd & trap_compare((int)regs->gpr[ra],
+                                               (int)regs->gpr[rb])))
+                                goto trap;
+                        goto instr_done;
+#ifdef __powerpc64__
+                case 68:        /* td */
+                        if (rd & trap_compare(regs->gpr[ra], regs->gpr[rb]))
+                                goto trap;
+                        goto instr_done;
+#endif
                 case 83:        /* mfmsr */
                         if (regs->msr & MSR_PR)
                                 goto priv;
@@ -1269,6 +1316,11 @@ int __kprobes analyse_instr(struct instruction_op *op, struct pt_regs *regs,
                         op->ea = xform_ea(instr, regs);
                         op->reg = rd;
                         return 0;
+
+                case 982:       /* icbi */
+                        op->type = MKOP(CACHEOP, ICBI, 0);
+                        op->ea = xform_ea(instr, regs);
+                        return 0;
                 }
                 break;
         }
@@ -1597,6 +1649,11 @@ int __kprobes analyse_instr(struct instruction_op *op, struct pt_regs *regs,
         op->val = SRR1_PROGPRIV;
         return 0;
 
+ trap:
+        op->type = INTERRUPT | 0x700;
+        op->val = SRR1_PROGTRAP;
+        return 0;
+
 #ifdef CONFIG_PPC_FPU
  fpunavail:
         op->type = INTERRUPT | 0x800;
@@ -1714,6 +1771,9 @@ int __kprobes emulate_step(struct pt_regs *regs, unsigned int instr)
                         if (op.reg == 0)
                                 prefetch((void *) op.ea);
                         break;
+                case ICBI:
+                        __cacheop_user_asmx(op.ea, err, "icbi");
+                        break;
                 }
                 if (err)
                         return 0;