powerpc: sstep: Add support for darn instruction

This adds emulation support for the following integer instructions:
  * Deliver A Random Number (darn)

As suggested by Michael, this uses a raw .long for specifying the
instruction word when using inline assembly to retain compatibility
with older binutils.

Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Sandipan Das 2019-02-22 12:23:28 +05:30 committed by Michael Ellerman
parent 930d6288a2
commit a23987ef26

View file

@ -1728,6 +1728,28 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
(int) regs->gpr[rb];
goto arith_done;
case 755: /* darn */
if (!cpu_has_feature(CPU_FTR_ARCH_300))
return -1;
switch (ra & 0x3) {
case 0:
/* 32-bit conditioned */
asm volatile(PPC_DARN(%0, 0) : "=r" (op->val));
goto compute_done;
case 1:
/* 64-bit conditioned */
asm volatile(PPC_DARN(%0, 1) : "=r" (op->val));
goto compute_done;
case 2:
/* 64-bit raw */
asm volatile(PPC_DARN(%0, 2) : "=r" (op->val));
goto compute_done;
}
return -1;
/*
* Logical instructions