[SPARC64]: Initial LDOM cpu hotplug support.

Only adding cpus is supports at the moment, removal
will come next.

When new cpus are configured, the machine description is
updated.  When we get the configure request we pass in a
cpu mask of to-be-added cpus to the mdesc CPU node parser
so it only fetches information for those cpus.  That code
also proceeds to update the SMT/multi-core scheduling bitmaps.

cpu_up() does all the work and we return the status back
over the DS channel.

CPUs via dr-cpu need to be booted straight out of the
hypervisor, and this requires:

1) A new trampoline mechanism.  CPUs are booted straight
   out of the hypervisor with MMU disabled and running in
   physical addresses with no mappings installed in the TLB.

   The new hvtramp.S code sets up the critical cpu state,
   installs the locked TLB mappings for the kernel, and
   turns the MMU on.  It then proceeds to follow the logic
   of the existing trampoline.S SMP cpu bringup code.

2) All calls into OBP have to be disallowed when domaining
   is enabled.  Since cpus boot straight into the kernel from
   the hypervisor, OBP has no state about that cpu and therefore
   cannot handle being invoked on that cpu.

   Luckily it's only a handful of interfaces which can be called
   after the OBP device tree is obtained.  For example, rebooting,
   halting, powering-off, and setting options node variables.

CPU removal support will require some infrastructure changes
here.  Namely we'll have to process the requests via a true
kernel thread instead of in a workqueue.  workqueues run on
a per-cpu thread, but when unconfiguring we might need to
force the thread to execute on another cpu if the current cpu
is the one being removed.  Removal of a cpu also causes the kernel
to destroy that cpu's workqueue running thread.

Another issue on removal is that we may have interrupts still
pointing to the cpu-to-be-removed.  So new code will be needed
to walk the active INO list and retarget those cpus as-needed.

Signed-off-by: David S. Miller <davem@davemloft.net>

16 files changed, 716 insertions, 128 deletions

diff --git a/arch/sparc64/Kconfig b/arch/sparc64/Kconfig
index af59daa81058..3c2e3397caf8 100644
--- a/arch/sparc64/Kconfig
+++ b/arch/sparc64/Kconfig
@@ -108,6 +108,15 @@ config SECCOMP
 
 source kernel/Kconfig.hz
 
+config HOTPLUG_CPU
+	bool "Support for hot-pluggable CPUs"
+	depends on SMP
+	select HOTPLUG
+	---help---
+	  Say Y here to experiment with turning CPUs off and on.  CPUs
+	  can be controlled through /sys/devices/system/cpu/cpu#.
+	  Say N if you want to disable CPU hotplug.
+
 source "init/Kconfig"
 
 config SYSVIPC_COMPAT
@@ -307,6 +316,7 @@ config SUN_IO
 
 config SUN_LDOMS
 	bool "Sun Logical Domains support"
+	select HOTPLUG_CPU
 	help
 	  Say Y here is you want to support virtual devices via
 	  Logical Domains.
diff --git a/arch/sparc64/kernel/Makefile b/arch/sparc64/kernel/Makefile
index 70e6c501392a..62db93c148cd 100644
--- a/arch/sparc64/kernel/Makefile
+++ b/arch/sparc64/kernel/Makefile
@@ -12,7 +12,8 @@ obj-y		:= process.o setup.o cpu.o idprom.o \
 		   irq.o ptrace.o time.o sys_sparc.o signal.o \
 		   unaligned.o central.o pci.o starfire.o semaphore.o \
 		   power.o sbus.o iommu_common.o sparc64_ksyms.o chmc.o \
-		   visemul.o prom.o of_device.o hvapi.o sstate.o mdesc.o
+		   visemul.o prom.o of_device.o hvapi.o sstate.o mdesc.o \
+		   hvtramp.o
 
 obj-$(CONFIG_STACKTRACE) += stacktrace.o
 obj-$(CONFIG_PCI)	 += ebus.o isa.o pci_common.o pci_iommu.o \
diff --git a/arch/sparc64/kernel/ds.c b/arch/sparc64/kernel/ds.c
index 4e20ef232c51..b82c03a25d9c 100644
--- a/arch/sparc64/kernel/ds.c
+++ b/arch/sparc64/kernel/ds.c
@@ -12,11 +12,16 @@
 #include <linux/sched.h>
 #include <linux/delay.h>
 #include <linux/mutex.h>
+#include <linux/workqueue.h>
+#include <linux/cpu.h>
 
 #include <asm/ldc.h>
 #include <asm/vio.h>
 #include <asm/power.h>
 #include <asm/mdesc.h>
+#include <asm/head.h>
+#include <asm/io.h>
+#include <asm/hvtramp.h>
 
 #define DRV_MODULE_NAME		"ds"
 #define PFX DRV_MODULE_NAME	": "
@@ -124,7 +129,7 @@ struct ds_cap_state {
 	__u64			handle;
 
 	void			(*data)(struct ldc_channel *lp,
-					struct ds_cap_state *dp,
+					struct ds_cap_state *cp,
 					void *buf, int len);
 
 	const char		*service_id;
@@ -135,6 +140,91 @@ struct ds_cap_state {
 #define CAP_STATE_REGISTERED	0x02
 };
 
+static void md_update_data(struct ldc_channel *lp, struct ds_cap_state *cp,
+			   void *buf, int len);
+static void domain_shutdown_data(struct ldc_channel *lp,
+				 struct ds_cap_state *cp,
+				 void *buf, int len);
+static void domain_panic_data(struct ldc_channel *lp,
+			      struct ds_cap_state *cp,
+			      void *buf, int len);
+static void dr_cpu_data(struct ldc_channel *lp,
+			struct ds_cap_state *cp,
+			void *buf, int len);
+static void ds_pri_data(struct ldc_channel *lp,
+			struct ds_cap_state *cp,
+			void *buf, int len);
+static void ds_var_data(struct ldc_channel *lp,
+			struct ds_cap_state *cp,
+			void *buf, int len);
+
+struct ds_cap_state ds_states[] = {
+	{
+		.service_id	= "md-update",
+		.data		= md_update_data,
+	},
+	{
+		.service_id	= "domain-shutdown",
+		.data		= domain_shutdown_data,
+	},
+	{
+		.service_id	= "domain-panic",
+		.data		= domain_panic_data,
+	},
+	{
+		.service_id	= "dr-cpu",
+		.data		= dr_cpu_data,
+	},
+	{
+		.service_id	= "pri",
+		.data		= ds_pri_data,
+	},
+	{
+		.service_id	= "var-config",
+		.data		= ds_var_data,
+	},
+	{
+		.service_id	= "var-config-backup",
+		.data		= ds_var_data,
+	},
+};
+
+static DEFINE_SPINLOCK(ds_lock);
+
+struct ds_info {
+	struct ldc_channel	*lp;
+	u8			hs_state;
+#define DS_HS_START		0x01
+#define DS_HS_DONE		0x02
+
+	void			*rcv_buf;
+	int			rcv_buf_len;
+};
+
+static struct ds_info *ds_info;
+
+static struct ds_cap_state *find_cap(u64 handle)
+{
+	unsigned int index = handle >> 32;
+
+	if (index >= ARRAY_SIZE(ds_states))
+		return NULL;
+	return &ds_states[index];
+}
+
+static struct ds_cap_state *find_cap_by_string(const char *name)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(ds_states); i++) {
+		if (strcmp(ds_states[i].service_id, name))
+			continue;
+
+		return &ds_states[i];
+	}
+	return NULL;
+}
+
 static int ds_send(struct ldc_channel *lp, void *data, int len)
 {
 	int err, limit = 1000;
@@ -265,36 +355,354 @@ static void domain_panic_data(struct ldc_channel *lp,
 	panic("PANIC requested by LDOM manager.");
 }
 
-struct ds_cpu_tag {
+struct dr_cpu_tag {
 	__u64				req_num;
 	__u32				type;
-#define DS_CPU_CONFIGURE		0x43
-#define DS_CPU_UNCONFIGURE		0x55
-#define DS_CPU_FORCE_UNCONFIGURE	0x46
-#define DS_CPU_STATUS			0x53
+#define DR_CPU_CONFIGURE		0x43
+#define DR_CPU_UNCONFIGURE		0x55
+#define DR_CPU_FORCE_UNCONFIGURE	0x46
+#define DR_CPU_STATUS			0x53
 
 /* Responses */
-#define DS_CPU_OK			0x6f
-#define DS_CPU_ERROR			0x65
+#define DR_CPU_OK			0x6f
+#define DR_CPU_ERROR			0x65
 
 	__u32				num_records;
 };
 
-struct ds_cpu_record {
-	__u32				cpu_id;
+struct dr_cpu_resp_entry {
+	__u32				cpu;
+	__u32				result;
+#define DR_CPU_RES_OK			0x00
+#define DR_CPU_RES_FAILURE		0x01
+#define DR_CPU_RES_BLOCKED		0x02
+#define DR_CPU_RES_CPU_NOT_RESPONDING	0x03
+#define DR_CPU_RES_NOT_IN_MD		0x04
+
+	__u32				stat;
+#define DR_CPU_STAT_NOT_PRESENT		0x00
+#define DR_CPU_STAT_UNCONFIGURED	0x01
+#define DR_CPU_STAT_CONFIGURED		0x02
+
+	__u32				str_off;
 };
 
+/* XXX Put this in some common place. XXX */
+static unsigned long kimage_addr_to_ra(void *p)
+{
+	unsigned long val = (unsigned long) p;
+
+	return kern_base + (val - KERNBASE);
+}
+
+void ldom_startcpu_cpuid(unsigned int cpu, unsigned long thread_reg)
+{
+	extern unsigned long sparc64_ttable_tl0;
+	extern unsigned long kern_locked_tte_data;
+	extern int bigkernel;
+	struct hvtramp_descr *hdesc;
+	unsigned long trampoline_ra;
+	struct trap_per_cpu *tb;
+	u64 tte_vaddr, tte_data;
+	unsigned long hv_err;
+
+	hdesc = kzalloc(sizeof(*hdesc), GFP_KERNEL);
+	if (!hdesc) {
+		printk(KERN_ERR PFX "ldom_startcpu_cpuid: Cannot allocate "
+		       "hvtramp_descr.\n");
+		return;
+	}
+
+	hdesc->cpu = cpu;
+	hdesc->num_mappings = (bigkernel ? 2 : 1);
+
+	tb = &trap_block[cpu];
+	tb->hdesc = hdesc;
+
+	hdesc->fault_info_va = (unsigned long) &tb->fault_info;
+	hdesc->fault_info_pa = kimage_addr_to_ra(&tb->fault_info);
+
+	hdesc->thread_reg = thread_reg;
+
+	tte_vaddr = (unsigned long) KERNBASE;
+	tte_data = kern_locked_tte_data;
+
+	hdesc->maps[0].vaddr = tte_vaddr;
+	hdesc->maps[0].tte   = tte_data;
+	if (bigkernel) {
+		tte_vaddr += 0x400000;
+		tte_data  += 0x400000;
+		hdesc->maps[1].vaddr = tte_vaddr;
+		hdesc->maps[1].tte   = tte_data;
+	}
+
+	trampoline_ra = kimage_addr_to_ra(hv_cpu_startup);
+
+	hv_err = sun4v_cpu_start(cpu, trampoline_ra,
+				 kimage_addr_to_ra(&sparc64_ttable_tl0),
+				 __pa(hdesc));
+}
+
+/* DR cpu requests get queued onto the work list by the
+ * dr_cpu_data() callback.  The list is protected by
+ * ds_lock, and processed by dr_cpu_process() in order.
+ */
+static LIST_HEAD(dr_cpu_work_list);
+
+struct dr_cpu_queue_entry {
+	struct list_head		list;
+	char				req[0];
+};
+
+static void __dr_cpu_send_error(struct ds_cap_state *cp, struct ds_data *data)
+{
+	struct dr_cpu_tag *tag = (struct dr_cpu_tag *) (data + 1);
+	struct ds_info *dp = ds_info;
+	struct {
+		struct ds_data		data;
+		struct dr_cpu_tag	tag;
+	} pkt;
+	int msg_len;
+
+	memset(&pkt, 0, sizeof(pkt));
+	pkt.data.tag.type = DS_DATA;
+	pkt.data.handle = cp->handle;
+	pkt.tag.req_num = tag->req_num;
+	pkt.tag.type = DR_CPU_ERROR;
+	pkt.tag.num_records = 0;
+
+	msg_len = (sizeof(struct ds_data) +
+		   sizeof(struct dr_cpu_tag));
+
+	pkt.data.tag.len = msg_len - sizeof(struct ds_msg_tag);
+
+	ds_send(dp->lp, &pkt, msg_len);
+}
+
+static void dr_cpu_send_error(struct ds_cap_state *cp, struct ds_data *data)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&ds_lock, flags);
+	__dr_cpu_send_error(cp, data);
+	spin_unlock_irqrestore(&ds_lock, flags);
+}
+
+#define CPU_SENTINEL	0xffffffff
+
+static void purge_dups(u32 *list, u32 num_ents)
+{
+	unsigned int i;
+
+	for (i = 0; i < num_ents; i++) {
+		u32 cpu = list[i];
+		unsigned int j;
+
+		if (cpu == CPU_SENTINEL)
+			continue;
+
+		for (j = i + 1; j < num_ents; j++) {
+			if (list[j] == cpu)
+				list[j] = CPU_SENTINEL;
+		}
+	}
+}
+
+static int dr_cpu_size_response(int ncpus)
+{
+	return (sizeof(struct ds_data) +
+		sizeof(struct dr_cpu_tag) +
+		(sizeof(struct dr_cpu_resp_entry) * ncpus));
+}
+
+static void dr_cpu_init_response(struct ds_data *resp, u64 req_num,
+				 u64 handle, int resp_len, int ncpus,
+				 cpumask_t *mask, u32 default_stat)
+{
+	struct dr_cpu_resp_entry *ent;
+	struct dr_cpu_tag *tag;
+	int i, cpu;
+
+	tag = (struct dr_cpu_tag *) (resp + 1);
+	ent = (struct dr_cpu_resp_entry *) (tag + 1);
+
+	resp->tag.type = DS_DATA;
+	resp->tag.len = resp_len - sizeof(struct ds_msg_tag);
+	resp->handle = handle;
+	tag->req_num = req_num;
+	tag->type = DR_CPU_OK;
+	tag->num_records = ncpus;
+
+	i = 0;
+	for_each_cpu_mask(cpu, *mask) {
+		ent[i].cpu = cpu;
+		ent[i].result = DR_CPU_RES_OK;
+		ent[i].stat = default_stat;
+		i++;
+	}
+	BUG_ON(i != ncpus);
+}
+
+static void dr_cpu_mark(struct ds_data *resp, int cpu, int ncpus,
+			u32 res, u32 stat)
+{
+	struct dr_cpu_resp_entry *ent;
+	struct dr_cpu_tag *tag;
+	int i;
+
+	tag = (struct dr_cpu_tag *) (resp + 1);
+	ent = (struct dr_cpu_resp_entry *) (tag + 1);
+
+	for (i = 0; i < ncpus; i++) {
+		if (ent[i].cpu != cpu)
+			continue;
+		ent[i].result = res;
+		ent[i].stat = stat;
+		break;
+	}
+}
+
+static int dr_cpu_configure(struct ds_cap_state *cp, u64 req_num,
+			    cpumask_t *mask)
+{
+	struct ds_data *resp;
+	int resp_len, ncpus, cpu;
+	unsigned long flags;
+
+	ncpus = cpus_weight(*mask);
+	resp_len = dr_cpu_size_response(ncpus);
+	resp = kzalloc(resp_len, GFP_KERNEL);
+	if (!resp)
+		return -ENOMEM;
+
+	dr_cpu_init_response(resp, req_num, cp->handle,
+			     resp_len, ncpus, mask,
+			     DR_CPU_STAT_CONFIGURED);
+
+	mdesc_fill_in_cpu_data(*mask);
+
+	for_each_cpu_mask(cpu, *mask) {
+		int err;
+
+		printk(KERN_INFO PFX "Starting cpu %d...\n", cpu);
+		err = cpu_up(cpu);
+		if (err)
+			dr_cpu_mark(resp, cpu, ncpus,
+				    DR_CPU_RES_FAILURE,
+				    DR_CPU_STAT_UNCONFIGURED);
+	}
+
+	spin_lock_irqsave(&ds_lock, flags);
+	ds_send(ds_info->lp, resp, resp_len);
+	spin_unlock_irqrestore(&ds_lock, flags);
+
+	kfree(resp);
+
+	return 0;
+}
+
+static int dr_cpu_unconfigure(struct ds_cap_state *cp, u64 req_num,
+			      cpumask_t *mask)
+{
+	struct ds_data *resp;
+	int resp_len, ncpus;
+
+	ncpus = cpus_weight(*mask);
+	resp_len = dr_cpu_size_response(ncpus);
+	resp = kzalloc(resp_len, GFP_KERNEL);
+	if (!resp)
+		return -ENOMEM;
+
+	dr_cpu_init_response(resp, req_num, cp->handle,
+			     resp_len, ncpus, mask,
+			     DR_CPU_STAT_UNCONFIGURED);
+
+	kfree(resp);
+
+	return -EOPNOTSUPP;
+}
+
+static void dr_cpu_process(struct work_struct *work)
+{
+	struct dr_cpu_queue_entry *qp, *tmp;
+	struct ds_cap_state *cp;
+	unsigned long flags;
+	LIST_HEAD(todo);
+	cpumask_t mask;
+
+	cp = find_cap_by_string("dr-cpu");
+
+	spin_lock_irqsave(&ds_lock, flags);
+	list_splice(&dr_cpu_work_list, &todo);
+	spin_unlock_irqrestore(&ds_lock, flags);
+
+	list_for_each_entry_safe(qp, tmp, &todo, list) {
+		struct ds_data *data = (struct ds_data *) qp->req;
+		struct dr_cpu_tag *tag = (struct dr_cpu_tag *) (data + 1);
+		u32 *cpu_list = (u32 *) (tag + 1);
+		u64 req_num = tag->req_num;
+		unsigned int i;
+		int err;
+
+		switch (tag->type) {
+		case DR_CPU_CONFIGURE:
+		case DR_CPU_UNCONFIGURE:
+		case DR_CPU_FORCE_UNCONFIGURE:
+			break;
+
+		default:
+			dr_cpu_send_error(cp, data);
+			goto next;
+		}
+
+		purge_dups(cpu_list, tag->num_records);
+
+		cpus_clear(mask);
+		for (i = 0; i < tag->num_records; i++) {
+			if (cpu_list[i] == CPU_SENTINEL)
+				continue;
+
+			if (cpu_list[i] < NR_CPUS)
+				cpu_set(cpu_list[i], mask);
+		}
+
+		if (tag->type == DR_CPU_CONFIGURE)
+			err = dr_cpu_configure(cp, req_num, &mask);
+		else
+			err = dr_cpu_unconfigure(cp, req_num, &mask);
+
+		if (err)
+			dr_cpu_send_error(cp, data);
+
+next:
+		list_del(&qp->list);
+		kfree(qp);
+	}
+}
+
+static DECLARE_WORK(dr_cpu_work, dr_cpu_process);
+
 static void dr_cpu_data(struct ldc_channel *lp,
 			struct ds_cap_state *dp,
 			void *buf, int len)
 {
+	struct dr_cpu_queue_entry *qp;
 	struct ds_data *dpkt = buf;
-	struct ds_cpu_tag *rp;
+	struct dr_cpu_tag *rp;
 
-	rp = (struct ds_cpu_tag *) (dpkt + 1);
+	rp = (struct dr_cpu_tag *) (dpkt + 1);
 
-	printk(KERN_ERR PFX "CPU REQ [%lx:%x], len=%d\n",
-	       rp->req_num, rp->type, len);
+	qp = kmalloc(sizeof(struct dr_cpu_queue_entry) + len, GFP_ATOMIC);
+	if (!qp) {
+		struct ds_cap_state *cp;
+
+		cp = find_cap_by_string("dr-cpu");
+		__dr_cpu_send_error(cp, dpkt);
+	} else {
+		memcpy(&qp->req, buf, len);
+		list_add_tail(&qp->list, &dr_cpu_work_list);
+		schedule_work(&dr_cpu_work);
+	}
 }
 
 struct ds_pri_msg {
@@ -368,73 +776,6 @@ static void ds_var_data(struct ldc_channel *lp,
 	ds_var_doorbell = 1;
 }
 
-struct ds_cap_state ds_states[] = {
-	{
-		.service_id	= "md-update",
-		.data		= md_update_data,
-	},
-	{
-		.service_id	= "domain-shutdown",
-		.data		= domain_shutdown_data,
-	},
-	{
-		.service_id	= "domain-panic",
-		.data		= domain_panic_data,
-	},
-	{
-		.service_id	= "dr-cpu",
-		.data		= dr_cpu_data,
-	},
-	{
-		.service_id	= "pri",
-		.data		= ds_pri_data,
-	},
-	{
-		.service_id	= "var-config",
-		.data		= ds_var_data,
-	},
-	{
-		.service_id	= "var-config-backup",
-		.data		= ds_var_data,
-	},
-};
-
-static DEFINE_SPINLOCK(ds_lock);
-
-struct ds_info {
-	struct ldc_channel	*lp;
-	u8			hs_state;
-#define DS_HS_START		0x01
-#define DS_HS_DONE		0x02
-
-	void			*rcv_buf;
-	int			rcv_buf_len;
-};
-
-static struct ds_info *ds_info;
-
-static struct ds_cap_state *find_cap(u64 handle)
-{
-	unsigned int index = handle >> 32;
-
-	if (index >= ARRAY_SIZE(ds_states))
-		return NULL;
-	return &ds_states[index];
-}
-
-static struct ds_cap_state *find_cap_by_string(const char *name)
-{
-	int i;
-
-	for (i = 0; i < ARRAY_SIZE(ds_states); i++) {
-		if (strcmp(ds_states[i].service_id, name))
-			continue;
-
-		return &ds_states[i];
-	}
-	return NULL;
-}
-
 void ldom_set_var(const char *var, const char *value)
 {
 	struct ds_info *dp = ds_info;
@@ -467,8 +808,8 @@ void ldom_set_var(const char *var, const char *value)
 		p += strlen(value) + 1;
 
 		msg_len = (sizeof(struct ds_data) +
-			       sizeof(struct ds_var_set_msg) +
-			       (p - base));
+			   sizeof(struct ds_var_set_msg) +
+			   (p - base));
 		msg_len = (msg_len + 3) & ~3;
 		pkt.header.data.tag.len = msg_len - sizeof(struct ds_msg_tag);
 
@@ -520,6 +861,11 @@ void ldom_reboot(const char *boot_command)
 	sun4v_mach_sir();
 }
 
+void ldom_power_off(void)
+{
+	sun4v_mach_exit(0);
+}
+
 static void ds_conn_reset(struct ds_info *dp)
 {
 	printk(KERN_ERR PFX "ds_conn_reset() from %p\n",
@@ -601,7 +947,7 @@ static int ds_handshake(struct ds_info *dp, struct ds_msg_tag *pkt)
 			       np->handle);
 			return 0;
 		}
-		printk(KERN_ERR PFX "Could not register %s service\n",
+		printk(KERN_INFO PFX "Could not register %s service\n",
 		       cp->service_id);
 		cp->state = CAP_STATE_UNKNOWN;
 	}
diff --git a/arch/sparc64/kernel/hvtramp.S b/arch/sparc64/kernel/hvtramp.S
new file mode 100644
index 000000000000..76a090e2c2a8
--- /dev/null
+++ b/arch/sparc64/kernel/hvtramp.S
@@ -0,0 +1,139 @@
+/* hvtramp.S: Hypervisor start-cpu trampoline code.
+ *
+ * Copyright (C) 2007 David S. Miller <davem@davemloft.net>
+ */
+
+#include <asm/thread_info.h>
+#include <asm/hypervisor.h>
+#include <asm/scratchpad.h>
+#include <asm/spitfire.h>
+#include <asm/hvtramp.h>
+#include <asm/pstate.h>
+#include <asm/ptrace.h>
+#include <asm/asi.h>
+
+	.text
+	.align		8
+	.globl		hv_cpu_startup, hv_cpu_startup_end
+
+	/* This code executes directly out of the hypervisor
+	 * with physical addressing (va==pa).  %o0 contains
+	 * our client argument which for Linux points to
+	 * a descriptor data structure which defines the
+	 * MMU entries we need to load up.
+	 *
+	 * After we set things up we enable the MMU and call
+	 * into the kernel.
+	 *
+	 * First setup basic privileged cpu state.
+	 */
+hv_cpu_startup:
+	wrpr		%g0, 0, %gl
+	wrpr		%g0, 15, %pil
+	wrpr		%g0, 0, %canrestore
+	wrpr		%g0, 0, %otherwin
+	wrpr		%g0, 6, %cansave
+	wrpr		%g0, 6, %cleanwin
+	wrpr		%g0, 0, %cwp
+	wrpr		%g0, 0, %wstate
+	wrpr		%g0, 0, %tl
+
+	sethi		%hi(sparc64_ttable_tl0), %g1
+	wrpr		%g1, %tba
+
+	mov		%o0, %l0
+
+	lduw		[%l0 + HVTRAMP_DESCR_CPU], %g1
+	mov		SCRATCHPAD_CPUID, %g2
+	stxa		%g1, [%g2] ASI_SCRATCHPAD
+
+	ldx		[%l0 + HVTRAMP_DESCR_FAULT_INFO_VA], %g2
+	stxa		%g2, [%g0] ASI_SCRATCHPAD
+
+	mov		0, %l1
+	lduw		[%l0 + HVTRAMP_DESCR_NUM_MAPPINGS], %l2
+	add		%l0, HVTRAMP_DESCR_MAPS, %l3
+
+1:	ldx		[%l3 + HVTRAMP_MAPPING_VADDR], %o0
+	clr		%o1
+	ldx		[%l3 + HVTRAMP_MAPPING_TTE], %o2
+	mov		HV_MMU_IMMU | HV_MMU_DMMU, %o3
+	mov		HV_FAST_MMU_MAP_PERM_ADDR, %o5
+	ta		HV_FAST_TRAP
+
+	brnz,pn		%o0, 80f
+	 nop
+
+	add		%l1, 1, %l1
+	cmp		%l1, %l2
+	blt,a,pt	%xcc, 1b
+	 add		%l3, HVTRAMP_MAPPING_SIZE, %l3
+
+	ldx		[%l0 + HVTRAMP_DESCR_FAULT_INFO_PA], %o0
+	mov		HV_FAST_MMU_FAULT_AREA_CONF, %o5
+	ta		HV_FAST_TRAP
+
+	brnz,pn		%o0, 80f
+	 nop
+
+	wrpr		%g0, (PSTATE_PRIV | PSTATE_PEF), %pstate
+
+	ldx		[%l0 + HVTRAMP_DESCR_THREAD_REG], %l6
+
+	mov		1, %o0
+	set		1f, %o1
+	mov		HV_FAST_MMU_ENABLE, %o5
+	ta		HV_FAST_TRAP
+
+	ba,pt		%xcc, 80f
+	 nop
+
+1:
+	wr		%g0, 0, %fprs
+	wr		%g0, ASI_P, %asi
+
+	mov		PRIMARY_CONTEXT, %g7
+	stxa		%g0, [%g7] ASI_MMU
+	membar		#Sync
+
+	mov		SECONDARY_CONTEXT, %g7
+	stxa		%g0, [%g7] ASI_MMU
+	membar		#Sync
+
+	mov		%l6, %g6
+	ldx		[%g6 + TI_TASK], %g4
+
+	mov		1, %g5
+	sllx		%g5, THREAD_SHIFT, %g5
+	sub		%g5, (STACKFRAME_SZ + STACK_BIAS), %g5
+	add		%g6, %g5, %sp
+	mov		0, %fp
+
+	call		init_irqwork_curcpu
+	 nop
+	call		hard_smp_processor_id
+	 nop
+
+	mov		%o0, %o1
+	mov		0, %o0
+	mov		0, %o2
+	call		sun4v_init_mondo_queues
+	 mov		1, %o3
+
+	call		init_cur_cpu_trap
+	 mov		%g6, %o0
+
+	wrpr		%g0, (PSTATE_PRIV | PSTATE_PEF | PSTATE_IE), %pstate
+
+	call		smp_callin
+	 nop
+	call		cpu_idle
+	 mov		0, %o0
+	call		cpu_panic
+	 nop
+
+80:	ba,pt		%xcc, 80b
+	 nop
+
+	.align		8
+hv_cpu_startup_end:
diff --git a/arch/sparc64/kernel/mdesc.c b/arch/sparc64/kernel/mdesc.c
index 9e5088d563cc..3f79940a2939 100644
--- a/arch/sparc64/kernel/mdesc.c
+++ b/arch/sparc64/kernel/mdesc.c
@@ -434,6 +434,22 @@ static void __init report_platform_properties(void)
 	if (v)
 		printk("PLATFORM: max-cpus [%lu]\n", *v);
 
+#ifdef CONFIG_SMP
+	{
+		int max_cpu, i;
+
+		if (v) {
+			max_cpu = *v;
+			if (max_cpu > NR_CPUS)
+				max_cpu = NR_CPUS;
+		} else {
+			max_cpu = NR_CPUS;
+		}
+		for (i = 0; i < max_cpu; i++)
+			cpu_set(i, cpu_possible_map);
+	}
+#endif
+
 	mdesc_release(hp);
 }
 
@@ -451,9 +467,9 @@ static int inline find_in_proplist(const char *list, const char *match, int len)
 	return 0;
 }
 
-static void __init fill_in_one_cache(cpuinfo_sparc *c,
-				     struct mdesc_handle *hp,
-				     u64 mp)
+static void __devinit fill_in_one_cache(cpuinfo_sparc *c,
+					struct mdesc_handle *hp,
+					u64 mp)
 {
 	const u64 *level = mdesc_get_property(hp, mp, "level", NULL);
 	const u64 *size = mdesc_get_property(hp, mp, "size", NULL);
@@ -496,7 +512,8 @@ static void __init fill_in_one_cache(cpuinfo_sparc *c,
 	}
 }
 
-static void __init mark_core_ids(struct mdesc_handle *hp, u64 mp, int core_id)
+static void __devinit mark_core_ids(struct mdesc_handle *hp, u64 mp,
+				    int core_id)
 {
 	u64 a;
 
@@ -529,7 +546,7 @@ static void __init mark_core_ids(struct mdesc_handle *hp, u64 mp, int core_id)
 	}
 }
 
-static void __init set_core_ids(struct mdesc_handle *hp)
+static void __devinit set_core_ids(struct mdesc_handle *hp)
 {
 	int idx;
 	u64 mp;
@@ -554,7 +571,8 @@ static void __init set_core_ids(struct mdesc_handle *hp)
 	}
 }
 
-static void __init mark_proc_ids(struct mdesc_handle *hp, u64 mp, int proc_id)
+static void __devinit mark_proc_ids(struct mdesc_handle *hp, u64 mp,
+				    int proc_id)
 {
 	u64 a;
 
@@ -573,8 +591,8 @@ static void __init mark_proc_ids(struct mdesc_handle *hp, u64 mp, int proc_id)
 	}
 }
 
-static void __init __set_proc_ids(struct mdesc_handle *hp,
-				  const char *exec_unit_name)
+static void __devinit __set_proc_ids(struct mdesc_handle *hp,
+				     const char *exec_unit_name)
 {
 	int idx;
 	u64 mp;
@@ -595,13 +613,14 @@ static void __init __set_proc_ids(struct mdesc_handle *hp,
 	}
 }
 
-static void __init set_proc_ids(struct mdesc_handle *hp)
+static void __devinit set_proc_ids(struct mdesc_handle *hp)
 {
 	__set_proc_ids(hp, "exec_unit");
 	__set_proc_ids(hp, "exec-unit");
 }
 
-static void __init get_one_mondo_bits(const u64 *p, unsigned int *mask, unsigned char def)
+static void __devinit get_one_mondo_bits(const u64 *p, unsigned int *mask,
+					 unsigned char def)
 {
 	u64 val;
 
@@ -619,8 +638,8 @@ use_default:
 	*mask = ((1U << def) * 64U) - 1U;
 }
 
-static void __init get_mondo_data(struct mdesc_handle *hp, u64 mp,
-				  struct trap_per_cpu *tb)
+static void __devinit get_mondo_data(struct mdesc_handle *hp, u64 mp,
+				     struct trap_per_cpu *tb)
 {
 	const u64 *val;
 
@@ -637,7 +656,7 @@ static void __init get_mondo_data(struct mdesc_handle *hp, u64 mp,
 	get_one_mondo_bits(val, &tb->nonresum_qmask, 2);
 }
 
-static void __init mdesc_fill_in_cpu_data(void)
+void __devinit mdesc_fill_in_cpu_data(cpumask_t mask)
 {
 	struct mdesc_handle *hp = mdesc_grab();
 	u64 mp;
@@ -658,6 +677,8 @@ static void __init mdesc_fill_in_cpu_data(void)
 #ifdef CONFIG_SMP
 		if (cpuid >= NR_CPUS)
 			continue;
+		if (!cpu_isset(cpuid, mask))
+			continue;
 #else
 		/* On uniprocessor we only want the values for the
 		 * real physical cpu the kernel booted onto, however
@@ -696,7 +717,6 @@ static void __init mdesc_fill_in_cpu_data(void)
 
 #ifdef CONFIG_SMP
 		cpu_set(cpuid, cpu_present_map);
-		cpu_set(cpuid, phys_cpu_present_map);
 #endif
 
 		c->core_id = 0;
@@ -719,6 +739,7 @@ void __init sun4v_mdesc_init(void)
 {
 	struct mdesc_handle *hp;
 	unsigned long len, real_len, status;
+	cpumask_t mask;
 
 	(void) sun4v_mach_desc(0UL, 0UL, &len);
 
@@ -742,5 +763,7 @@ void __init sun4v_mdesc_init(void)
 	cur_mdesc = hp;
 
 	report_platform_properties();
-	mdesc_fill_in_cpu_data();
+
+	cpus_setall(mask);
+	mdesc_fill_in_cpu_data(mask);
 }
diff --git a/arch/sparc64/kernel/prom.c b/arch/sparc64/kernel/prom.c
index 61036b346664..5d220302cd50 100644
--- a/arch/sparc64/kernel/prom.c
+++ b/arch/sparc64/kernel/prom.c
@@ -1808,7 +1808,7 @@ static void __init of_fill_in_cpu_data(void)
 
 #ifdef CONFIG_SMP
 		cpu_set(cpuid, cpu_present_map);
-		cpu_set(cpuid, phys_cpu_present_map);
+		cpu_set(cpuid, cpu_possible_map);
 #endif
 	}
 
diff --git a/arch/sparc64/kernel/smp.c b/arch/sparc64/kernel/smp.c
index 40e40f968d61..315eef0869bd 100644
--- a/arch/sparc64/kernel/smp.c
+++ b/arch/sparc64/kernel/smp.c
@@ -41,6 +41,7 @@
 #include <asm/sections.h>
 #include <asm/prom.h>
 #include <asm/mdesc.h>
+#include <asm/ldc.h>
 
 extern void calibrate_delay(void);
 
@@ -49,12 +50,18 @@ int sparc64_multi_core __read_mostly;
 /* Please don't make this stuff initdata!!!  --DaveM */
 unsigned char boot_cpu_id;
 
+cpumask_t cpu_possible_map __read_mostly = CPU_MASK_NONE;
 cpumask_t cpu_online_map __read_mostly = CPU_MASK_NONE;
-cpumask_t phys_cpu_present_map __read_mostly = CPU_MASK_NONE;
 cpumask_t cpu_sibling_map[NR_CPUS] __read_mostly =
 	{ [0 ... NR_CPUS-1] = CPU_MASK_NONE };
 cpumask_t cpu_core_map[NR_CPUS] __read_mostly =
 	{ [0 ... NR_CPUS-1] = CPU_MASK_NONE };
+
+EXPORT_SYMBOL(cpu_possible_map);
+EXPORT_SYMBOL(cpu_online_map);
+EXPORT_SYMBOL(cpu_sibling_map);
+EXPORT_SYMBOL(cpu_core_map);
+
 static cpumask_t smp_commenced_mask;
 static cpumask_t cpu_callout_map;
 
@@ -84,9 +91,10 @@ extern void setup_sparc64_timer(void);
 
 static volatile unsigned long callin_flag = 0;
 
-void __init smp_callin(void)
+void __devinit smp_callin(void)
 {
 	int cpuid = hard_smp_processor_id();
+	struct trap_per_cpu *tb = &trap_block[cpuid];;
 
 	__local_per_cpu_offset = __per_cpu_offset(cpuid);
 
@@ -117,6 +125,11 @@ void __init smp_callin(void)
 	atomic_inc(&init_mm.mm_count);
 	current->active_mm = &init_mm;
 
+	if (tb->hdesc) {
+		kfree(tb->hdesc);
+		tb->hdesc = NULL;
+	}
+
 	while (!cpu_isset(cpuid, smp_commenced_mask))
 		rmb();
 
@@ -296,14 +309,20 @@ static int __devinit smp_boot_one_cpu(unsigned int cpu)
 		/* Alloc the mondo queues, cpu will load them.  */
 		sun4v_init_mondo_queues(0, cpu, 1, 0);
 
-		prom_startcpu_cpuid(cpu, entry, cookie);
+#ifdef CONFIG_SUN_LDOMS
+		if (ldom_domaining_enabled)
+			ldom_startcpu_cpuid(cpu,
+					    (unsigned long) cpu_new_thread);
+		else
+#endif
+			prom_startcpu_cpuid(cpu, entry, cookie);
 	} else {
 		struct device_node *dp = of_find_node_by_cpuid(cpu);
 
 		prom_startcpu(dp->node, entry, cookie);
 	}
 
-	for (timeout = 0; timeout < 5000000; timeout++) {
+	for (timeout = 0; timeout < 50000; timeout++) {
 		if (callin_flag)
 			break;
 		udelay(100);
@@ -1163,22 +1182,8 @@ int setup_profiling_timer(unsigned int multiplier)
 	return -EINVAL;
 }
 
-/* Constrain the number of cpus to max_cpus.  */
 void __init smp_prepare_cpus(unsigned int max_cpus)
 {
-	int i;
-
-	if (num_possible_cpus() > max_cpus) {
-		for_each_possible_cpu(i) {
-			if (i != boot_cpu_id) {
-				cpu_clear(i, phys_cpu_present_map);
-				cpu_clear(i, cpu_present_map);
-				if (num_possible_cpus() <= max_cpus)
-					break;
-			}
-		}
-	}
-
 	cpu_data(boot_cpu_id).udelay_val = loops_per_jiffy;
 }
 
@@ -1242,6 +1247,20 @@ int __cpuinit __cpu_up(unsigned int cpu)
 	return ret;
 }
 
+#ifdef CONFIG_HOTPLUG_CPU
+int __cpu_disable(void)
+{
+	printk(KERN_ERR "SMP: __cpu_disable() on cpu %d\n",
+	       smp_processor_id());
+	return -ENODEV;
+}
+
+void __cpu_die(unsigned int cpu)
+{
+	printk(KERN_ERR "SMP: __cpu_die(%u)\n", cpu);
+}
+#endif
+
 void __init smp_cpus_done(unsigned int max_cpus)
 {
 	unsigned long bogosum = 0;
diff --git a/arch/sparc64/kernel/sparc64_ksyms.c b/arch/sparc64/kernel/sparc64_ksyms.c
index 6fa761612899..51e059e36d47 100644
--- a/arch/sparc64/kernel/sparc64_ksyms.c
+++ b/arch/sparc64/kernel/sparc64_ksyms.c
@@ -124,10 +124,6 @@ EXPORT_SYMBOL(__write_lock);
 EXPORT_SYMBOL(__write_unlock);
 EXPORT_SYMBOL(__write_trylock);
 
-/* CPU online map and active count.  */
-EXPORT_SYMBOL(cpu_online_map);
-EXPORT_SYMBOL(phys_cpu_present_map);
-
 EXPORT_SYMBOL(smp_call_function);
 #endif /* CONFIG_SMP */
 
diff --git a/arch/sparc64/prom/misc.c b/arch/sparc64/prom/misc.c
index 72d272c9de6b..33c5b7da31e5 100644
--- a/arch/sparc64/prom/misc.c
+++ b/arch/sparc64/prom/misc.c
@@ -96,6 +96,10 @@ void prom_cmdline(void)
  */
 void prom_halt(void)
 {
+#ifdef CONFIG_SUN_LDOMS
+	if (ldom_domaining_enabled)
+		ldom_power_off();
+#endif
 again:
 	p1275_cmd("exit", P1275_INOUT(0, 0));
 	goto again; /* PROM is out to get me -DaveM */
@@ -103,6 +107,10 @@ again:
 
 void prom_halt_power_off(void)
 {
+#ifdef CONFIG_SUN_LDOMS
+	if (ldom_domaining_enabled)
+		ldom_power_off();
+#endif
 	p1275_cmd("SUNW,power-off", P1275_INOUT(0, 0));
 
 	/* if nothing else helps, we just halt */
diff --git a/arch/sparc64/prom/p1275.c b/arch/sparc64/prom/p1275.c
index 2b32c489860c..7fcccc0e19cf 100644
--- a/arch/sparc64/prom/p1275.c
+++ b/arch/sparc64/prom/p1275.c
@@ -16,6 +16,7 @@
 #include <asm/system.h>
 #include <asm/spitfire.h>
 #include <asm/pstate.h>
+#include <asm/ldc.h>
 
 struct {
 	long prom_callback;			/* 0x00 */
diff --git a/include/asm-sparc64/cpudata.h b/include/asm-sparc64/cpudata.h
index 445026fbec35..0016d8b4531c 100644
--- a/include/asm-sparc64/cpudata.h
+++ b/include/asm-sparc64/cpudata.h
@@ -80,7 +80,8 @@ struct trap_per_cpu {
 	unsigned int		dev_mondo_qmask;
 	unsigned int		resum_qmask;
 	unsigned int		nonresum_qmask;
-	unsigned int		__pad2[3];
+	unsigned int		__pad2[1];
+	void			*hdesc;
 } __attribute__((aligned(64)));
 extern struct trap_per_cpu trap_block[NR_CPUS];
 extern void init_cur_cpu_trap(struct thread_info *);
diff --git a/include/asm-sparc64/hvtramp.h b/include/asm-sparc64/hvtramp.h
new file mode 100644
index 000000000000..c7dd6ad056df
--- /dev/null
+++ b/include/asm-sparc64/hvtramp.h
@@ -0,0 +1,37 @@
+#ifndef _SPARC64_HVTRAP_H
+#define _SPARC64_HVTRAP_H
+
+#ifndef __ASSEMBLY__
+
+#include <linux/types.h>
+
+struct hvtramp_mapping {
+	__u64		vaddr;
+	__u64		tte;
+};
+
+struct hvtramp_descr {
+	__u32			cpu;
+	__u32			num_mappings;
+	__u64			fault_info_va;
+	__u64			fault_info_pa;
+	__u64			thread_reg;
+	struct hvtramp_mapping	maps[2];
+};
+
+extern void hv_cpu_startup(unsigned long hvdescr_pa);
+
+#endif
+
+#define HVTRAMP_DESCR_CPU		0x00
+#define HVTRAMP_DESCR_NUM_MAPPINGS	0x04
+#define HVTRAMP_DESCR_FAULT_INFO_VA	0x08
+#define HVTRAMP_DESCR_FAULT_INFO_PA	0x10
+#define HVTRAMP_DESCR_THREAD_REG	0x18
+#define HVTRAMP_DESCR_MAPS		0x20
+
+#define HVTRAMP_MAPPING_VADDR		0x00
+#define HVTRAMP_MAPPING_TTE		0x08
+#define HVTRAMP_MAPPING_SIZE		0x10
+
+#endif /* _SPARC64_HVTRAP_H */
diff --git a/include/asm-sparc64/hypervisor.h b/include/asm-sparc64/hypervisor.h
index db2130a95d68..524d49835dfd 100644
--- a/include/asm-sparc64/hypervisor.h
+++ b/include/asm-sparc64/hypervisor.h
@@ -98,7 +98,7 @@
 #define HV_FAST_MACH_EXIT		0x00
 
 #ifndef __ASSEMBLY__
-extern void sun4v_mach_exit(unsigned long exit_core);
+extern void sun4v_mach_exit(unsigned long exit_code);
 #endif
 
 /* Domain services.  */
diff --git a/include/asm-sparc64/ldc.h b/include/asm-sparc64/ldc.h
index a21996c6b155..8d17bd6bd5db 100644
--- a/include/asm-sparc64/ldc.h
+++ b/include/asm-sparc64/ldc.h
@@ -6,6 +6,8 @@
 extern int ldom_domaining_enabled;
 extern void ldom_set_var(const char *var, const char *value);
 extern void ldom_reboot(const char *boot_command);
+extern void ldom_power_off(void);
+extern void ldom_startcpu_cpuid(unsigned int cpu, unsigned long thread_reg);
 
 /* The event handler will be evoked when link state changes
  * or data becomes available on the receive side.
diff --git a/include/asm-sparc64/mdesc.h b/include/asm-sparc64/mdesc.h
index dc372df23fb3..e97c43133752 100644
--- a/include/asm-sparc64/mdesc.h
+++ b/include/asm-sparc64/mdesc.h
@@ -2,6 +2,7 @@
 #define _SPARC64_MDESC_H
 
 #include <linux/types.h>
+#include <linux/cpumask.h>
 #include <asm/prom.h>
 
 struct mdesc_handle;
@@ -60,6 +61,8 @@ extern u64 mdesc_arc_target(struct mdesc_handle *hp, u64 arc);
 
 extern void mdesc_update(void);
 
+extern void mdesc_fill_in_cpu_data(cpumask_t mask);
+
 extern void sun4v_mdesc_init(void);
 
 #endif
diff --git a/include/asm-sparc64/smp.h b/include/asm-sparc64/smp.h
index 4fb8c4bfb848..c42c5a035c73 100644
--- a/include/asm-sparc64/smp.h
+++ b/include/asm-sparc64/smp.h
@@ -29,9 +29,6 @@
 #include <asm/bitops.h>
 #include <asm/atomic.h>
 
-extern cpumask_t phys_cpu_present_map;
-#define cpu_possible_map phys_cpu_present_map
-
 extern cpumask_t cpu_sibling_map[NR_CPUS];
 extern cpumask_t cpu_core_map[NR_CPUS];
 extern int sparc64_multi_core;
@@ -46,6 +43,11 @@ extern int hard_smp_processor_id(void);
 extern void smp_fill_in_sib_core_maps(void);
 extern unsigned char boot_cpu_id;
 
+#ifdef CONFIG_HOTPLUG_CPU
+extern int __cpu_disable(void);
+extern void __cpu_die(unsigned int cpu);
+#endif
+
 #endif /* !(__ASSEMBLY__) */
 
 #else