/* 
 * 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/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 || cpu == get_cpu()) {
                /* don't care, or already on correct cpu */
                sn_hwperf_call_sal(op_info);
        }
        else {
                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);