[SPARC64]: Report proper system soft state to the hypervisor.

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/arch/sparc64/kernel/sstate.c b/arch/sparc64/kernel/sstate.c
new file mode 100644
index 0000000..5b6e75b
--- /dev/null
+++ b/arch/sparc64/kernel/sstate.c
@@ -0,0 +1,104 @@
+/* sstate.c: System soft state support.
+ *
+ * Copyright (C) 2007 David S. Miller <davem@davemloft.net>
+ */
+
+#include <linux/kernel.h>
+#include <linux/notifier.h>
+#include <linux/init.h>
+
+#include <asm/hypervisor.h>
+#include <asm/sstate.h>
+#include <asm/oplib.h>
+#include <asm/head.h>
+#include <asm/io.h>
+
+static int hv_supports_soft_state;
+
+static unsigned long kimage_addr_to_ra(const char *p)
+{
+	unsigned long val = (unsigned long) p;
+
+	return kern_base + (val - KERNBASE);
+}
+
+static void do_set_sstate(unsigned long state, const char *msg)
+{
+	unsigned long err;
+
+	if (!hv_supports_soft_state)
+		return;
+
+	err = sun4v_mach_set_soft_state(state, kimage_addr_to_ra(msg));
+	if (err) {
+		printk(KERN_WARNING "SSTATE: Failed to set soft-state to "
+		       "state[%lx] msg[%s], err=%lu\n",
+		       state, msg, err);
+	}
+}
+
+static const char booting_msg[32] __attribute__((aligned(32))) =
+	"Linux booting";
+static const char running_msg[32] __attribute__((aligned(32))) =
+	"Linux running";
+static const char halting_msg[32] __attribute__((aligned(32))) =
+	"Linux halting";
+static const char poweroff_msg[32] __attribute__((aligned(32))) =
+	"Linux powering off";
+static const char rebooting_msg[32] __attribute__((aligned(32))) =
+	"Linux rebooting";
+static const char panicing_msg[32] __attribute__((aligned(32))) =
+	"Linux panicing";
+
+void sstate_booting(void)
+{
+	do_set_sstate(HV_SOFT_STATE_TRANSITION, booting_msg);
+}
+
+void sstate_running(void)
+{
+	do_set_sstate(HV_SOFT_STATE_NORMAL, running_msg);
+}
+
+void sstate_halt(void)
+{
+	do_set_sstate(HV_SOFT_STATE_TRANSITION, halting_msg);
+}
+
+void sstate_poweroff(void)
+{
+	do_set_sstate(HV_SOFT_STATE_TRANSITION, poweroff_msg);
+}
+
+void sstate_reboot(void)
+{
+	do_set_sstate(HV_SOFT_STATE_TRANSITION, rebooting_msg);
+}
+
+static int sstate_panic_event(struct notifier_block *n, unsigned long event, void *ptr)
+{
+	do_set_sstate(HV_SOFT_STATE_TRANSITION, panicing_msg);
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block sstate_panic_block = {
+	.notifier_call	=	sstate_panic_event,
+	.priority	=	INT_MAX,
+};
+
+void __init sun4v_sstate_init(void)
+{
+	unsigned long major, minor;
+
+	major = 1;
+	minor = 0;
+	if (sun4v_hvapi_register(HV_GRP_SOFT_STATE, major, &minor))
+		return;
+
+	hv_supports_soft_state = 1;
+
+	prom_sun4v_guest_soft_state();
+	atomic_notifier_chain_register(&panic_notifier_list,
+				       &sstate_panic_block);
+}