powerpc/pseries: add definitions for new H_SIGNAL_SYS_RESET hcall

This has not made its way to a PAPR release yet, but we have an hcall
number assigned.

  H_SIGNAL_SYS_RESET = 0x380

  Syntax:
    hcall(uint64 H_SIGNAL_SYS_RESET, int64 target);

  Generate a system reset NMI on the threads indicated by target.

  Values for target:
    -1 = target all online threads including the caller
    -2 = target all online threads except for the caller
    All other negative values: reserved
    Positive values: The thread to be targeted, obtained from the value
    of the "ibm,ppc-interrupt-server#s" property of the CPU in the OF
    device tree.

  Semantics:
  - Invalid target: return H_Parameter.
  - Otherwise: Generate a system reset NMI on target thread(s),
    return H_Success.

This will be used by crash/debug code to get stuck CPUs into a known
state.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/include/asm/hvcall.h

@@ -276,7 +276,8 @@
 #define H_GET_MPP_X		0x314
 #define H_SET_MODE		0x31C
 #define H_CLEAR_HPT		0x358
-#define MAX_HCALL_OPCODE	H_CLEAR_HPT
+#define H_SIGNAL_SYS_RESET	0x380
+#define MAX_HCALL_OPCODE	H_SIGNAL_SYS_RESET
 
 /* H_VIOCTL functions */
 #define H_GET_VIOA_DUMP_SIZE	0x01
@@ -307,6 +308,11 @@
 #define H_SET_MODE_RESOURCE_ADDR_TRANS_MODE	3
 #define H_SET_MODE_RESOURCE_LE			4
 
+/* Values for argument to H_SIGNAL_SYS_RESET */
+#define H_SIGNAL_SYS_RESET_ALL			-1
+#define H_SIGNAL_SYS_RESET_ALL_OTHERS		-2
+/* >= 0 values are CPU number */
+
 #ifndef __ASSEMBLY__
 
 /**

arch/powerpc/include/asm/plpar_wrappers.h

@@ -308,4 +308,9 @@ static inline long plapr_set_watchpoint0(unsigned long dawr0, unsigned long dawr
 	return plpar_set_mode(0, H_SET_MODE_RESOURCE_SET_DAWR, dawr0, dawrx0);
 }
 
+static inline long plapr_signal_sys_reset(long cpu)
+{
+	return plpar_hcall_norets(H_SIGNAL_SYS_RESET, cpu);
+}
+
 #endif /* _ASM_POWERPC_PLPAR_WRAPPERS_H */