parisc: add __pdc_cpu_rendezvous()

When stopping SMP cpus send them into rendezvous, so we can
start them again later (when kexec'ing a new kernel).

Signed-off-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Helge Deller <deller@gmx.de>

arch/parisc/include/asm/pdc.h

@@ -91,6 +91,7 @@ int pdc_sti_call(unsigned long func, unsigned long flags,
                  unsigned long inptr, unsigned long outputr,
                  unsigned long glob_cfg);
 
+int __pdc_cpu_rendezvous(void);
 static inline char * os_id_to_string(u16 os_id) {
 	switch(os_id) {
 	case OS_ID_NONE:	return "No OS";

arch/parisc/kernel/firmware.c

@@ -311,6 +311,19 @@ int pdc_chassis_disp(unsigned long disp)
 	return retval;
 }
 
+/**
+ * pdc_cpu_rendenzvous - Stop currently executing CPU
+ * @retval: -1 on error, 0 on success
+ */
+int __pdc_cpu_rendezvous(void)
+{
+	if (is_pdc_pat())
+		return mem_pdc_call(PDC_PAT_CPU, PDC_PAT_CPU_RENDEZVOUS);
+	else
+		return mem_pdc_call(PDC_PROC, 1, 0);
+}
+
+
 /**
  * pdc_chassis_warn - Fetches chassis warnings
  * @retval: -1 on error, 0 on success

arch/parisc/kernel/smp.c

@@ -109,6 +109,7 @@ halt_processor(void)
 	/* REVISIT : does PM *know* this CPU isn't available? */
 	set_cpu_online(smp_processor_id(), false);
 	local_irq_disable();
+	__pdc_cpu_rendezvous();
 	for (;;)
 		;
 }