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>

diff --git a/arch/powerpc/include/asm/sstep.h b/arch/powerpc/include/asm/sstep.h
index 1a693b13ddc539a0d17ecf237504efac68825c04..d3a42cc45a8286023b47f98403229e02f8e1f238 100644 (file)
--- a/arch/powerpc/include/asm/sstep.h
+++ b/arch/powerpc/include/asm/sstep.h
@@ -66,6 +66,7 @@ enum instruction_type {
 #define DCBF           0x100
 #define DCBTST         0x200
 #define DCBT           0x300
+#define ICBI           0x400
 
 /* Size field in type word */
 #define SIZE(n)                ((n) << 8)

diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index 3726a03179ab16a46408d6bb72f9486e9c8b7433..209a506f8517e2f49cad323ac301c8b117f549d3 100644 (file)
--- 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;