init android origin source code

1 files changed, 1003 insertions, 0 deletions

diff --git a/ANDROID_3.4.5/arch/ia64/sn/kernel/sn2/sn_hwperf.c b/ANDROID_3.4.5/arch/ia64/sn/kernel/sn2/sn_hwperf.c
new file mode 100644
index 00000000..4554f68b
--- /dev/null
+++ b/ANDROID_3.4.5/arch/ia64/sn/kernel/sn2/sn_hwperf.c
@@ -0,0 +1,1003 @@
+/* 
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2004-2006 Silicon Graphics, Inc. All rights reserved.
+ *
+ * SGI Altix topology and hardware performance monitoring API.
+ * Mark Goodwin <markgw@sgi.com>. 
+ *
+ * Creates /proc/sgi_sn/sn_topology (read-only) to export
+ * info about Altix nodes, routers, CPUs and NumaLink
+ * interconnection/topology.
+ *
+ * Also creates a dynamic misc device named "sn_hwperf"
+ * that supports an ioctl interface to call down into SAL
+ * to discover hw objects, topology and to read/write
+ * memory mapped registers, e.g. for performance monitoring.
+ * The "sn_hwperf" device is registered only after the procfs
+ * file is first opened, i.e. only if/when it's needed. 
+ *
+ * This API is used by SGI Performance Co-Pilot and other
+ * tools, see http://oss.sgi.com/projects/pcp
+ */
+
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/export.h>
+#include <linux/vmalloc.h>
+#include <linux/seq_file.h>
+#include <linux/miscdevice.h>
+#include <linux/utsname.h>
+#include <linux/cpumask.h>
+#include <linux/nodemask.h>
+#include <linux/smp.h>
+#include <linux/mutex.h>
+
+#include <asm/processor.h>
+#include <asm/topology.h>
+#include <asm/uaccess.h>
+#include <asm/sal.h>
+#include <asm/sn/io.h>
+#include <asm/sn/sn_sal.h>
+#include <asm/sn/module.h>
+#include <asm/sn/geo.h>
+#include <asm/sn/sn2/sn_hwperf.h>
+#include <asm/sn/addrs.h>
+
+static void *sn_hwperf_salheap = NULL;
+static int sn_hwperf_obj_cnt = 0;
+static nasid_t sn_hwperf_master_nasid = INVALID_NASID;
+static int sn_hwperf_init(void);
+static DEFINE_MUTEX(sn_hwperf_init_mutex);
+
+#define cnode_possible(n)	((n) < num_cnodes)
+
+static int sn_hwperf_enum_objects(int *nobj, struct sn_hwperf_object_info **ret)
+{
+	int e;
+	u64 sz;
+	struct sn_hwperf_object_info *objbuf = NULL;
+
+	if ((e = sn_hwperf_init()) < 0) {
+		printk(KERN_ERR "sn_hwperf_init failed: err %d\n", e);
+		goto out;
+	}
+
+	sz = sn_hwperf_obj_cnt * sizeof(struct sn_hwperf_object_info);
+	objbuf = vmalloc(sz);
+	if (objbuf == NULL) {
+		printk("sn_hwperf_enum_objects: vmalloc(%d) failed\n", (int)sz);
+		e = -ENOMEM;
+		goto out;
+	}
+
+	e = ia64_sn_hwperf_op(sn_hwperf_master_nasid, SN_HWPERF_ENUM_OBJECTS,
+		0, sz, (u64) objbuf, 0, 0, NULL);
+	if (e != SN_HWPERF_OP_OK) {
+		e = -EINVAL;
+		vfree(objbuf);
+	}
+
+out:
+	*nobj = sn_hwperf_obj_cnt;
+	*ret = objbuf;
+	return e;
+}
+
+static int sn_hwperf_location_to_bpos(char *location,
+	int *rack, int *bay, int *slot, int *slab)
+{
+	char type;
+
+	/* first scan for an old style geoid string */
+	if (sscanf(location, "%03d%c%02d#%d",
+		rack, &type, bay, slab) == 4)
+		*slot = 0; 
+	else /* scan for a new bladed geoid string */
+	if (sscanf(location, "%03d%c%02d^%02d#%d",
+		rack, &type, bay, slot, slab) != 5)
+		return -1; 
+	/* success */
+	return 0;
+}
+
+static int sn_hwperf_geoid_to_cnode(char *location)
+{
+	int cnode;
+	geoid_t geoid;
+	moduleid_t module_id;
+	int rack, bay, slot, slab;
+	int this_rack, this_bay, this_slot, this_slab;
+
+	if (sn_hwperf_location_to_bpos(location, &rack, &bay, &slot, &slab))
+		return -1;
+
+	/*
+	 * FIXME: replace with cleaner for_each_XXX macro which addresses
+	 * both compute and IO nodes once ACPI3.0 is available.
+	 */
+	for (cnode = 0; cnode < num_cnodes; cnode++) {
+		geoid = cnodeid_get_geoid(cnode);
+		module_id = geo_module(geoid);
+		this_rack = MODULE_GET_RACK(module_id);
+		this_bay = MODULE_GET_BPOS(module_id);
+		this_slot = geo_slot(geoid);
+		this_slab = geo_slab(geoid);
+		if (rack == this_rack && bay == this_bay &&
+			slot == this_slot && slab == this_slab) {
+			break;
+		}
+	}
+
+	return cnode_possible(cnode) ? cnode : -1;
+}
+
+static int sn_hwperf_obj_to_cnode(struct sn_hwperf_object_info * obj)
+{
+	if (!SN_HWPERF_IS_NODE(obj) && !SN_HWPERF_IS_IONODE(obj))
+		BUG();
+	if (SN_HWPERF_FOREIGN(obj))
+		return -1;
+	return sn_hwperf_geoid_to_cnode(obj->location);
+}
+
+static int sn_hwperf_generic_ordinal(struct sn_hwperf_object_info *obj,
+				struct sn_hwperf_object_info *objs)
+{
+	int ordinal;
+	struct sn_hwperf_object_info *p;
+
+	for (ordinal=0, p=objs; p != obj; p++) {
+		if (SN_HWPERF_FOREIGN(p))
+			continue;
+		if (SN_HWPERF_SAME_OBJTYPE(p, obj))
+			ordinal++;
+	}
+
+	return ordinal;
+}
+
+static const char *slabname_node =	"node"; /* SHub asic */
+static const char *slabname_ionode =	"ionode"; /* TIO asic */
+static const char *slabname_router =	"router"; /* NL3R or NL4R */
+static const char *slabname_other =	"other"; /* unknown asic */
+
+static const char *sn_hwperf_get_slabname(struct sn_hwperf_object_info *obj,
+			struct sn_hwperf_object_info *objs, int *ordinal)
+{
+	int isnode;
+	const char *slabname = slabname_other;
+
+	if ((isnode = SN_HWPERF_IS_NODE(obj)) || SN_HWPERF_IS_IONODE(obj)) {
+	    	slabname = isnode ? slabname_node : slabname_ionode;
+		*ordinal = sn_hwperf_obj_to_cnode(obj);
+	}
+	else {
+		*ordinal = sn_hwperf_generic_ordinal(obj, objs);
+		if (SN_HWPERF_IS_ROUTER(obj))
+			slabname = slabname_router;
+	}
+
+	return slabname;
+}
+
+static void print_pci_topology(struct seq_file *s)
+{
+	char *p;
+	size_t sz;
+	int e;
+
+	for (sz = PAGE_SIZE; sz < 16 * PAGE_SIZE; sz += PAGE_SIZE) {
+		if (!(p = kmalloc(sz, GFP_KERNEL)))
+			break;
+		e = ia64_sn_ioif_get_pci_topology(__pa(p), sz);
+		if (e == SALRET_OK)
+			seq_puts(s, p);
+		kfree(p);
+		if (e == SALRET_OK || e == SALRET_NOT_IMPLEMENTED)
+			break;
+	}
+}
+
+static inline int sn_hwperf_has_cpus(cnodeid_t node)
+{
+	return node < MAX_NUMNODES && node_online(node) && nr_cpus_node(node);
+}
+
+static inline int sn_hwperf_has_mem(cnodeid_t node)
+{
+	return node < MAX_NUMNODES && node_online(node) && NODE_DATA(node)->node_present_pages;
+}
+
+static struct sn_hwperf_object_info *
+sn_hwperf_findobj_id(struct sn_hwperf_object_info *objbuf,
+	int nobj, int id)
+{
+	int i;
+	struct sn_hwperf_object_info *p = objbuf;
+
+	for (i=0; i < nobj; i++, p++) {
+		if (p->id == id)
+			return p;
+	}
+
+	return NULL;
+
+}
+
+static int sn_hwperf_get_nearest_node_objdata(struct sn_hwperf_object_info *objbuf,
+	int nobj, cnodeid_t node, cnodeid_t *near_mem_node, cnodeid_t *near_cpu_node)
+{
+	int e;
+	struct sn_hwperf_object_info *nodeobj = NULL;
+	struct sn_hwperf_object_info *op;
+	struct sn_hwperf_object_info *dest;
+	struct sn_hwperf_object_info *router;
+	struct sn_hwperf_port_info ptdata[16];
+	int sz, i, j;
+	cnodeid_t c;
+	int found_mem = 0;
+	int found_cpu = 0;
+
+	if (!cnode_possible(node))
+		return -EINVAL;
+
+	if (sn_hwperf_has_cpus(node)) {
+		if (near_cpu_node)
+			*near_cpu_node = node;
+		found_cpu++;
+	}
+
+	if (sn_hwperf_has_mem(node)) {
+		if (near_mem_node)
+			*near_mem_node = node;
+		found_mem++;
+	}
+
+	if (found_cpu && found_mem)
+		return 0; /* trivially successful */
+
+	/* find the argument node object */
+	for (i=0, op=objbuf; i < nobj; i++, op++) {
+		if (!SN_HWPERF_IS_NODE(op) && !SN_HWPERF_IS_IONODE(op))
+			continue;
+		if (node == sn_hwperf_obj_to_cnode(op)) {
+			nodeobj = op;
+			break;
+		}
+	}
+	if (!nodeobj) {
+		e = -ENOENT;
+		goto err;
+	}
+
+	/* get it's interconnect topology */
+	sz = op->ports * sizeof(struct sn_hwperf_port_info);
+	BUG_ON(sz > sizeof(ptdata));
+	e = ia64_sn_hwperf_op(sn_hwperf_master_nasid,
+			      SN_HWPERF_ENUM_PORTS, nodeobj->id, sz,
+			      (u64)&ptdata, 0, 0, NULL);
+	if (e != SN_HWPERF_OP_OK) {
+		e = -EINVAL;
+		goto err;
+	}
+
+	/* find nearest node with cpus and nearest memory */
+	for (router=NULL, j=0; j < op->ports; j++) {
+		dest = sn_hwperf_findobj_id(objbuf, nobj, ptdata[j].conn_id);
+		if (dest && SN_HWPERF_IS_ROUTER(dest))
+			router = dest;
+		if (!dest || SN_HWPERF_FOREIGN(dest) ||
+		    !SN_HWPERF_IS_NODE(dest) || SN_HWPERF_IS_IONODE(dest)) {
+			continue;
+		}
+		c = sn_hwperf_obj_to_cnode(dest);
+		if (!found_cpu && sn_hwperf_has_cpus(c)) {
+			if (near_cpu_node)
+				*near_cpu_node = c;
+			found_cpu++;
+		}
+		if (!found_mem && sn_hwperf_has_mem(c)) {
+			if (near_mem_node)
+				*near_mem_node = c;
+			found_mem++;
+		}
+	}
+
+	if (router && (!found_cpu || !found_mem)) {
+		/* search for a node connected to the same router */
+		sz = router->ports * sizeof(struct sn_hwperf_port_info);
+		BUG_ON(sz > sizeof(ptdata));
+		e = ia64_sn_hwperf_op(sn_hwperf_master_nasid,
+				      SN_HWPERF_ENUM_PORTS, router->id, sz,
+				      (u64)&ptdata, 0, 0, NULL);
+		if (e != SN_HWPERF_OP_OK) {
+			e = -EINVAL;
+			goto err;
+		}
+		for (j=0; j < router->ports; j++) {
+			dest = sn_hwperf_findobj_id(objbuf, nobj,
+				ptdata[j].conn_id);
+			if (!dest || dest->id == node ||
+			    SN_HWPERF_FOREIGN(dest) ||
+			    !SN_HWPERF_IS_NODE(dest) ||
+			    SN_HWPERF_IS_IONODE(dest)) {
+				continue;
+			}
+			c = sn_hwperf_obj_to_cnode(dest);
+			if (!found_cpu && sn_hwperf_has_cpus(c)) {
+				if (near_cpu_node)
+					*near_cpu_node = c;
+				found_cpu++;
+			}
+			if (!found_mem && sn_hwperf_has_mem(c)) {
+				if (near_mem_node)
+					*near_mem_node = c;
+				found_mem++;
+			}
+			if (found_cpu && found_mem)
+				break;
+		}
+	}
+
+	if (!found_cpu || !found_mem) {
+		/* resort to _any_ node with CPUs and memory */
+		for (i=0, op=objbuf; i < nobj; i++, op++) {
+			if (SN_HWPERF_FOREIGN(op) ||
+			    SN_HWPERF_IS_IONODE(op) ||
+			    !SN_HWPERF_IS_NODE(op)) {
+				continue;
+			}
+			c = sn_hwperf_obj_to_cnode(op);
+			if (!found_cpu && sn_hwperf_has_cpus(c)) {
+				if (near_cpu_node)
+					*near_cpu_node = c;
+				found_cpu++;
+			}
+			if (!found_mem && sn_hwperf_has_mem(c)) {
+				if (near_mem_node)
+					*near_mem_node = c;
+				found_mem++;
+			}
+			if (found_cpu && found_mem)
+				break;
+		}
+	}
+
+	if (!found_cpu || !found_mem)
+		e = -ENODATA;
+
+err:
+	return e;
+}
+
+
+static int sn_topology_show(struct seq_file *s, void *d)
+{
+	int sz;
+	int pt;
+	int e = 0;
+	int i;
+	int j;
+	const char *slabname;
+	int ordinal;
+	char slice;
+	struct cpuinfo_ia64 *c;
+	struct sn_hwperf_port_info *ptdata;
+	struct sn_hwperf_object_info *p;
+	struct sn_hwperf_object_info *obj = d;	/* this object */
+	struct sn_hwperf_object_info *objs = s->private; /* all objects */
+	u8 shubtype;
+	u8 system_size;
+	u8 sharing_size;
+	u8 partid;
+	u8 coher;
+	u8 nasid_shift;
+	u8 region_size;
+	u16 nasid_mask;
+	int nasid_msb;
+
+	if (obj == objs) {
+		seq_printf(s, "# sn_topology version 2\n");
+		seq_printf(s, "# objtype ordinal location partition"
+			" [attribute value [, ...]]\n");
+
+		if (ia64_sn_get_sn_info(0,
+			&shubtype, &nasid_mask, &nasid_shift, &system_size,
+			&sharing_size, &partid, &coher, &region_size))
+			BUG();
+		for (nasid_msb=63; nasid_msb > 0; nasid_msb--) {
+			if (((u64)nasid_mask << nasid_shift) & (1ULL << nasid_msb))
+				break;
+		}
+		seq_printf(s, "partition %u %s local "
+			"shubtype %s, "
+			"nasid_mask 0x%016llx, "
+			"nasid_bits %d:%d, "
+			"system_size %d, "
+			"sharing_size %d, "
+			"coherency_domain %d, "
+			"region_size %d\n",
+
+			partid, utsname()->nodename,
+			shubtype ? "shub2" : "shub1", 
+			(u64)nasid_mask << nasid_shift, nasid_msb, nasid_shift,
+			system_size, sharing_size, coher, region_size);
+
+		print_pci_topology(s);
+	}
+
+	if (SN_HWPERF_FOREIGN(obj)) {
+		/* private in another partition: not interesting */
+		return 0;
+	}
+
+	for (i = 0; i < SN_HWPERF_MAXSTRING && obj->name[i]; i++) {
+		if (obj->name[i] == ' ')
+			obj->name[i] = '_';
+	}
+
+	slabname = sn_hwperf_get_slabname(obj, objs, &ordinal);
+	seq_printf(s, "%s %d %s %s asic %s", slabname, ordinal, obj->location,
+		obj->sn_hwp_this_part ? "local" : "shared", obj->name);
+
+	if (ordinal < 0 || (!SN_HWPERF_IS_NODE(obj) && !SN_HWPERF_IS_IONODE(obj)))
+		seq_putc(s, '\n');
+	else {
+		cnodeid_t near_mem = -1;
+		cnodeid_t near_cpu = -1;
+
+		seq_printf(s, ", nasid 0x%x", cnodeid_to_nasid(ordinal));
+
+		if (sn_hwperf_get_nearest_node_objdata(objs, sn_hwperf_obj_cnt,
+			ordinal, &near_mem, &near_cpu) == 0) {
+			seq_printf(s, ", near_mem_nodeid %d, near_cpu_nodeid %d",
+				near_mem, near_cpu);
+		}
+
+		if (!SN_HWPERF_IS_IONODE(obj)) {
+			for_each_online_node(i) {
+				seq_printf(s, i ? ":%d" : ", dist %d",
+					node_distance(ordinal, i));
+			}
+		}
+
+		seq_putc(s, '\n');
+
+		/*
+		 * CPUs on this node, if any
+		 */
+		if (!SN_HWPERF_IS_IONODE(obj)) {
+			for_each_cpu_and(i, cpu_online_mask,
+					 cpumask_of_node(ordinal)) {
+				slice = 'a' + cpuid_to_slice(i);
+				c = cpu_data(i);
+				seq_printf(s, "cpu %d %s%c local"
+					   " freq %luMHz, arch ia64",
+					   i, obj->location, slice,
+					   c->proc_freq / 1000000);
+				for_each_online_cpu(j) {
+					seq_printf(s, j ? ":%d" : ", dist %d",
+						   node_distance(
+						    	cpu_to_node(i),
+						    	cpu_to_node(j)));
+				}
+				seq_putc(s, '\n');
+			}
+		}
+	}
+
+	if (obj->ports) {
+		/*
+		 * numalink ports
+		 */
+		sz = obj->ports * sizeof(struct sn_hwperf_port_info);
+		if ((ptdata = kmalloc(sz, GFP_KERNEL)) == NULL)
+			return -ENOMEM;
+		e = ia64_sn_hwperf_op(sn_hwperf_master_nasid,
+				      SN_HWPERF_ENUM_PORTS, obj->id, sz,
+				      (u64) ptdata, 0, 0, NULL);
+		if (e != SN_HWPERF_OP_OK)
+			return -EINVAL;
+		for (ordinal=0, p=objs; p != obj; p++) {
+			if (!SN_HWPERF_FOREIGN(p))
+				ordinal += p->ports;
+		}
+		for (pt = 0; pt < obj->ports; pt++) {
+			for (p = objs, i = 0; i < sn_hwperf_obj_cnt; i++, p++) {
+				if (ptdata[pt].conn_id == p->id) {
+					break;
+				}
+			}
+			seq_printf(s, "numalink %d %s-%d",
+			    ordinal+pt, obj->location, ptdata[pt].port);
+
+			if (i >= sn_hwperf_obj_cnt) {
+				/* no connection */
+				seq_puts(s, " local endpoint disconnected"
+					    ", protocol unknown\n");
+				continue;
+			}
+
+			if (obj->sn_hwp_this_part && p->sn_hwp_this_part)
+				/* both ends local to this partition */
+				seq_puts(s, " local");
+			else if (SN_HWPERF_FOREIGN(p))
+				/* both ends of the link in foreign partiton */
+				seq_puts(s, " foreign");
+			else
+				/* link straddles a partition */
+				seq_puts(s, " shared");
+
+			/*
+			 * Unlikely, but strictly should query the LLP config
+			 * registers because an NL4R can be configured to run
+			 * NL3 protocol, even when not talking to an NL3 router.
+			 * Ditto for node-node.
+			 */
+			seq_printf(s, " endpoint %s-%d, protocol %s\n",
+				p->location, ptdata[pt].conn_port,
+				(SN_HWPERF_IS_NL3ROUTER(obj) ||
+				SN_HWPERF_IS_NL3ROUTER(p)) ?  "LLP3" : "LLP4");
+		}
+		kfree(ptdata);
+	}
+
+	return 0;
+}
+
+static void *sn_topology_start(struct seq_file *s, loff_t * pos)
+{
+	struct sn_hwperf_object_info *objs = s->private;
+
+	if (*pos < sn_hwperf_obj_cnt)
+		return (void *)(objs + *pos);
+
+	return NULL;
+}
+
+static void *sn_topology_next(struct seq_file *s, void *v, loff_t * pos)
+{
+	++*pos;
+	return sn_topology_start(s, pos);
+}
+
+static void sn_topology_stop(struct seq_file *m, void *v)
+{
+	return;
+}
+
+/*
+ * /proc/sgi_sn/sn_topology, read-only using seq_file
+ */
+static const struct seq_operations sn_topology_seq_ops = {
+	.start = sn_topology_start,
+	.next = sn_topology_next,
+	.stop = sn_topology_stop,
+	.show = sn_topology_show
+};
+
+struct sn_hwperf_op_info {
+	u64 op;
+	struct sn_hwperf_ioctl_args *a;
+	void *p;
+	int *v0;
+	int ret;
+};
+
+static void sn_hwperf_call_sal(void *info)
+{
+	struct sn_hwperf_op_info *op_info = info;
+	int r;
+
+	r = ia64_sn_hwperf_op(sn_hwperf_master_nasid, op_info->op,
+		      op_info->a->arg, op_info->a->sz,
+		      (u64) op_info->p, 0, 0, op_info->v0);
+	op_info->ret = r;
+}
+
+static int sn_hwperf_op_cpu(struct sn_hwperf_op_info *op_info)
+{
+	u32 cpu;
+	u32 use_ipi;
+	int r = 0;
+	cpumask_t save_allowed;
+	
+	cpu = (op_info->a->arg & SN_HWPERF_ARG_CPU_MASK) >> 32;
+	use_ipi = op_info->a->arg & SN_HWPERF_ARG_USE_IPI_MASK;
+	op_info->a->arg &= SN_HWPERF_ARG_OBJID_MASK;
+
+	if (cpu != SN_HWPERF_ARG_ANY_CPU) {
+		if (cpu >= nr_cpu_ids || !cpu_online(cpu)) {
+			r = -EINVAL;
+			goto out;
+		}
+	}
+
+	if (cpu == SN_HWPERF_ARG_ANY_CPU) {
+		/* don't care which cpu */
+		sn_hwperf_call_sal(op_info);
+	} else if (cpu == get_cpu()) {
+		/* already on correct cpu */
+		sn_hwperf_call_sal(op_info);
+		put_cpu();
+	} else {
+		put_cpu();
+		if (use_ipi) {
+			/* use an interprocessor interrupt to call SAL */
+			smp_call_function_single(cpu, sn_hwperf_call_sal,
+				op_info, 1);
+		}
+		else {
+			/* migrate the task before calling SAL */ 
+			save_allowed = current->cpus_allowed;
+			set_cpus_allowed_ptr(current, cpumask_of(cpu));
+			sn_hwperf_call_sal(op_info);
+			set_cpus_allowed_ptr(current, &save_allowed);
+		}
+	}
+	r = op_info->ret;
+
+out:
+	return r;
+}
+
+/* map SAL hwperf error code to system error code */
+static int sn_hwperf_map_err(int hwperf_err)
+{
+	int e;
+
+	switch(hwperf_err) {
+	case SN_HWPERF_OP_OK:
+		e = 0;
+		break;
+
+	case SN_HWPERF_OP_NOMEM:
+		e = -ENOMEM;
+		break;
+
+	case SN_HWPERF_OP_NO_PERM:
+		e = -EPERM;
+		break;
+
+	case SN_HWPERF_OP_IO_ERROR:
+		e = -EIO;
+		break;
+
+	case SN_HWPERF_OP_BUSY:
+		e = -EBUSY;
+		break;
+
+	case SN_HWPERF_OP_RECONFIGURE:
+		e = -EAGAIN;
+		break;
+
+	case SN_HWPERF_OP_INVAL:
+	default:
+		e = -EINVAL;
+		break;
+	}
+
+	return e;
+}
+
+/*
+ * ioctl for "sn_hwperf" misc device
+ */
+static long sn_hwperf_ioctl(struct file *fp, u32 op, unsigned long arg)
+{
+	struct sn_hwperf_ioctl_args a;
+	struct cpuinfo_ia64 *cdata;
+	struct sn_hwperf_object_info *objs;
+	struct sn_hwperf_object_info *cpuobj;
+	struct sn_hwperf_op_info op_info;
+	void *p = NULL;
+	int nobj;
+	char slice;
+	int node;
+	int r;
+	int v0;
+	int i;
+	int j;
+
+	/* only user requests are allowed here */
+	if ((op & SN_HWPERF_OP_MASK) < 10) {
+		r = -EINVAL;
+		goto error;
+	}
+	r = copy_from_user(&a, (const void __user *)arg,
+		sizeof(struct sn_hwperf_ioctl_args));
+	if (r != 0) {
+		r = -EFAULT;
+		goto error;
+	}
+
+	/*
+	 * Allocate memory to hold a kernel copy of the user buffer. The
+	 * buffer contents are either copied in or out (or both) of user
+	 * space depending on the flags encoded in the requested operation.
+	 */
+	if (a.ptr) {
+		p = vmalloc(a.sz);
+		if (!p) {
+			r = -ENOMEM;
+			goto error;
+		}
+	}
+
+	if (op & SN_HWPERF_OP_MEM_COPYIN) {
+		r = copy_from_user(p, (const void __user *)a.ptr, a.sz);
+		if (r != 0) {
+			r = -EFAULT;
+			goto error;
+		}
+	}
+
+	switch (op) {
+	case SN_HWPERF_GET_CPU_INFO:
+		if (a.sz == sizeof(u64)) {
+			/* special case to get size needed */
+			*(u64 *) p = (u64) num_online_cpus() *
+				sizeof(struct sn_hwperf_object_info);
+		} else
+		if (a.sz < num_online_cpus() * sizeof(struct sn_hwperf_object_info)) {
+			r = -ENOMEM;
+			goto error;
+		} else
+		if ((r = sn_hwperf_enum_objects(&nobj, &objs)) == 0) {
+			int cpuobj_index = 0;
+
+			memset(p, 0, a.sz);
+			for (i = 0; i < nobj; i++) {
+				if (!SN_HWPERF_IS_NODE(objs + i))
+					continue;
+				node = sn_hwperf_obj_to_cnode(objs + i);
+				for_each_online_cpu(j) {
+					if (node != cpu_to_node(j))
+						continue;
+					cpuobj = (struct sn_hwperf_object_info *) p + cpuobj_index++;
+					slice = 'a' + cpuid_to_slice(j);
+					cdata = cpu_data(j);
+					cpuobj->id = j;
+					snprintf(cpuobj->name,
+						 sizeof(cpuobj->name),
+						 "CPU %luMHz %s",
+						 cdata->proc_freq / 1000000,
+						 cdata->vendor);
+					snprintf(cpuobj->location,
+						 sizeof(cpuobj->location),
+						 "%s%c", objs[i].location,
+						 slice);
+				}
+			}
+
+			vfree(objs);
+		}
+		break;
+
+	case SN_HWPERF_GET_NODE_NASID:
+		if (a.sz != sizeof(u64) ||
+		   (node = a.arg) < 0 || !cnode_possible(node)) {
+			r = -EINVAL;
+			goto error;
+		}
+		*(u64 *)p = (u64)cnodeid_to_nasid(node);
+		break;
+
+	case SN_HWPERF_GET_OBJ_NODE:
+		i = a.arg;
+		if (a.sz != sizeof(u64) || i < 0) {
+			r = -EINVAL;
+			goto error;
+		}
+		if ((r = sn_hwperf_enum_objects(&nobj, &objs)) == 0) {
+			if (i >= nobj) {
+				r = -EINVAL;
+				vfree(objs);
+				goto error;
+			}
+			if (objs[i].id != a.arg) {
+				for (i = 0; i < nobj; i++) {
+					if (objs[i].id == a.arg)
+						break;
+				}
+			}
+			if (i == nobj) {
+				r = -EINVAL;
+				vfree(objs);
+				goto error;
+			}
+
+			if (!SN_HWPERF_IS_NODE(objs + i) &&
+			    !SN_HWPERF_IS_IONODE(objs + i)) {
+			    	r = -ENOENT;
+				vfree(objs);
+				goto error;
+			}
+
+			*(u64 *)p = (u64)sn_hwperf_obj_to_cnode(objs + i);
+			vfree(objs);
+		}
+		break;
+
+	case SN_HWPERF_GET_MMRS:
+	case SN_HWPERF_SET_MMRS:
+	case SN_HWPERF_OBJECT_DISTANCE:
+		op_info.p = p;
+		op_info.a = &a;
+		op_info.v0 = &v0;
+		op_info.op = op;
+		r = sn_hwperf_op_cpu(&op_info);
+		if (r) {
+			r = sn_hwperf_map_err(r);
+			a.v0 = v0;
+			goto error;
+		}
+		break;
+
+	default:
+		/* all other ops are a direct SAL call */
+		r = ia64_sn_hwperf_op(sn_hwperf_master_nasid, op,
+			      a.arg, a.sz, (u64) p, 0, 0, &v0);
+		if (r) {
+			r = sn_hwperf_map_err(r);
+			goto error;
+		}
+		a.v0 = v0;
+		break;
+	}
+
+	if (op & SN_HWPERF_OP_MEM_COPYOUT) {
+		r = copy_to_user((void __user *)a.ptr, p, a.sz);
+		if (r != 0) {
+			r = -EFAULT;
+			goto error;
+		}
+	}
+
+error:
+	vfree(p);
+
+	return r;
+}
+
+static const struct file_operations sn_hwperf_fops = {
+	.unlocked_ioctl = sn_hwperf_ioctl,
+	.llseek = noop_llseek,
+};
+
+static struct miscdevice sn_hwperf_dev = {
+	MISC_DYNAMIC_MINOR,
+	"sn_hwperf",
+	&sn_hwperf_fops
+};
+
+static int sn_hwperf_init(void)
+{
+	u64 v;
+	int salr;
+	int e = 0;
+
+	/* single threaded, once-only initialization */
+	mutex_lock(&sn_hwperf_init_mutex);
+
+	if (sn_hwperf_salheap) {
+		mutex_unlock(&sn_hwperf_init_mutex);
+		return e;
+	}
+
+	/*
+	 * The PROM code needs a fixed reference node. For convenience the
+	 * same node as the console I/O is used.
+	 */
+	sn_hwperf_master_nasid = (nasid_t) ia64_sn_get_console_nasid();
+
+	/*
+	 * Request the needed size and install the PROM scratch area.
+	 * The PROM keeps various tracking bits in this memory area.
+	 */
+	salr = ia64_sn_hwperf_op(sn_hwperf_master_nasid,
+				 (u64) SN_HWPERF_GET_HEAPSIZE, 0,
+				 (u64) sizeof(u64), (u64) &v, 0, 0, NULL);
+	if (salr != SN_HWPERF_OP_OK) {
+		e = -EINVAL;
+		goto out;
+	}
+
+	if ((sn_hwperf_salheap = vmalloc(v)) == NULL) {
+		e = -ENOMEM;
+		goto out;
+	}
+	salr = ia64_sn_hwperf_op(sn_hwperf_master_nasid,
+				 SN_HWPERF_INSTALL_HEAP, 0, v,
+				 (u64) sn_hwperf_salheap, 0, 0, NULL);
+	if (salr != SN_HWPERF_OP_OK) {
+		e = -EINVAL;
+		goto out;
+	}
+
+	salr = ia64_sn_hwperf_op(sn_hwperf_master_nasid,
+				 SN_HWPERF_OBJECT_COUNT, 0,
+				 sizeof(u64), (u64) &v, 0, 0, NULL);
+	if (salr != SN_HWPERF_OP_OK) {
+		e = -EINVAL;
+		goto out;
+	}
+	sn_hwperf_obj_cnt = (int)v;
+
+out:
+	if (e < 0 && sn_hwperf_salheap) {
+		vfree(sn_hwperf_salheap);
+		sn_hwperf_salheap = NULL;
+		sn_hwperf_obj_cnt = 0;
+	}
+	mutex_unlock(&sn_hwperf_init_mutex);
+	return e;
+}
+
+int sn_topology_open(struct inode *inode, struct file *file)
+{
+	int e;
+	struct seq_file *seq;
+	struct sn_hwperf_object_info *objbuf;
+	int nobj;
+
+	if ((e = sn_hwperf_enum_objects(&nobj, &objbuf)) == 0) {
+		e = seq_open(file, &sn_topology_seq_ops);
+		seq = file->private_data;
+		seq->private = objbuf;
+	}
+
+	return e;
+}
+
+int sn_topology_release(struct inode *inode, struct file *file)
+{
+	struct seq_file *seq = file->private_data;
+
+	vfree(seq->private);
+	return seq_release(inode, file);
+}
+
+int sn_hwperf_get_nearest_node(cnodeid_t node,
+	cnodeid_t *near_mem_node, cnodeid_t *near_cpu_node)
+{
+	int e;
+	int nobj;
+	struct sn_hwperf_object_info *objbuf;
+
+	if ((e = sn_hwperf_enum_objects(&nobj, &objbuf)) == 0) {
+		e = sn_hwperf_get_nearest_node_objdata(objbuf, nobj,
+			node, near_mem_node, near_cpu_node);
+		vfree(objbuf);
+	}
+
+	return e;
+}
+
+static int __devinit sn_hwperf_misc_register_init(void)
+{
+	int e;
+
+	if (!ia64_platform_is("sn2"))
+		return 0;
+
+	sn_hwperf_init();
+
+	/*
+	 * Register a dynamic misc device for hwperf ioctls. Platforms
+	 * supporting hotplug will create /dev/sn_hwperf, else user
+	 * can to look up the minor number in /proc/misc.
+	 */
+	if ((e = misc_register(&sn_hwperf_dev)) != 0) {
+		printk(KERN_ERR "sn_hwperf_misc_register_init: failed to "
+		"register misc device for \"%s\"\n", sn_hwperf_dev.name);
+	}
+
+	return e;
+}
+
+device_initcall(sn_hwperf_misc_register_init); /* after misc_init() */
+EXPORT_SYMBOL(sn_hwperf_get_nearest_node);