9 files changed, 553 insertions, 474 deletions

diff --git a/arch/sparc64/kernel/ds.c b/arch/sparc64/kernel/ds.c
index c7ece8c52039..9c8839d1cffd 100644
--- a/arch/sparc64/kernel/ds.c
+++ b/arch/sparc64/kernel/ds.c
@@ -15,6 +15,7 @@
 #include <asm/ldc.h>
 #include <asm/vio.h>
 #include <asm/power.h>
+#include <asm/mdesc.h>
 
 #define DRV_MODULE_NAME         "ds"
 #define PFX DRV_MODULE_NAME     ": "
@@ -170,8 +171,7 @@ static void md_update_data(struct ldc_channel *lp,
 
         rp = (struct ds_md_update_req *) (dpkt + 1);
 
-        printk(KERN_ERR PFX "MD update REQ [%lx] len=%d\n",
-               rp->req_num, len);
+        printk(KERN_ERR PFX "Machine description update.\n");
 
         memset(&pkt, 0, sizeof(pkt));
         pkt.data.tag.type = DS_DATA;
@@ -181,6 +181,8 @@ static void md_update_data(struct ldc_channel *lp,
         pkt.res.result = DS_OK;
 
         ds_send(lp, &pkt, sizeof(pkt));
+
+        mdesc_update();
 }
 
 struct ds_shutdown_req {
@@ -555,7 +557,6 @@ static int __devinit ds_probe(struct vio_dev *vdev,
                               const struct vio_device_id *id)
 {
         static int ds_version_printed;
-        struct mdesc_node *endp;
         struct ldc_channel_config ds_cfg = {
                 .event          = ds_event,
                 .mtu            = 4096,
@@ -563,20 +564,11 @@ static int __devinit ds_probe(struct vio_dev *vdev,
         };
         struct ldc_channel *lp;
         struct ds_info *dp;
-        const u64 *chan_id;
         int err;
 
         if (ds_version_printed++ == 0)
                 printk(KERN_INFO "%s", version);
 
-        endp = vio_find_endpoint(vdev);
-        if (!endp)
-                return -ENODEV;
-
-        chan_id = md_get_property(endp, "id", NULL);
-        if (!chan_id)
-                return -ENODEV;
-
         dp = kzalloc(sizeof(*dp), GFP_KERNEL);
         err = -ENOMEM;
         if (!dp)
@@ -588,10 +580,10 @@ static int __devinit ds_probe(struct vio_dev *vdev,
 
         dp->rcv_buf_len = 4096;
 
-        ds_cfg.tx_irq = endp->irqs[0];
-        ds_cfg.rx_irq = endp->irqs[1];
+        ds_cfg.tx_irq = vdev->tx_irq;
+        ds_cfg.rx_irq = vdev->rx_irq;
 
-        lp = ldc_alloc(*chan_id, &ds_cfg, dp);
+        lp = ldc_alloc(vdev->channel_id, &ds_cfg, dp);
         if (IS_ERR(lp)) {
                 err = PTR_ERR(lp);
                 goto out_free_rcv_buf;
diff --git a/arch/sparc64/kernel/ldc.c b/arch/sparc64/kernel/ldc.c
index dbb65b674a67..85a2be0b0962 100644
--- a/arch/sparc64/kernel/ldc.c
+++ b/arch/sparc64/kernel/ldc.c
@@ -2335,15 +2335,20 @@ EXPORT_SYMBOL(ldc_free_exp_dring);
 
 static int __init ldc_init(void)
 {
-        struct mdesc_node *mp;
         unsigned long major, minor;
+        struct mdesc_handle *hp;
         const u64 *v;
+        u64 mp;
 
-        mp = md_find_node_by_name(NULL, "platform");
-        if (!mp)
+        hp = mdesc_grab();
+        if (!hp)
                 return -ENODEV;
 
-        v = md_get_property(mp, "domaining-enabled", NULL);
+        mp = mdesc_node_by_name(hp, MDESC_NODE_NULL, "platform");
+        if (mp == MDESC_NODE_NULL)
+                return -ENODEV;
+
+        v = mdesc_get_property(hp, mp, "domaining-enabled", NULL);
         if (!v)
                 return -ENODEV;
 
diff --git a/arch/sparc64/kernel/mdesc.c b/arch/sparc64/kernel/mdesc.c
index f0e16045fb16..9e5088d563cc 100644
--- a/arch/sparc64/kernel/mdesc.c
+++ b/arch/sparc64/kernel/mdesc.c
@@ -6,6 +6,8 @@
 #include <linux/types.h>
 #include <linux/bootmem.h>
 #include <linux/log2.h>
+#include <linux/list.h>
+#include <linux/slab.h>
 
 #include <asm/hypervisor.h>
 #include <asm/mdesc.h>
@@ -29,7 +31,7 @@ struct mdesc_hdr {
         u32     node_sz; /* node block size */
         u32     name_sz; /* name block size */
         u32     data_sz; /* data block size */
-};
+} __attribute__((aligned(16)));
 
 struct mdesc_elem {
         u8      tag;
@@ -53,306 +55,386 @@ struct mdesc_elem {
         } d;
 };
 
-static struct mdesc_hdr *main_mdesc;
-static struct mdesc_node *allnodes;
-
-static struct mdesc_node *allnodes_tail;
-static unsigned int unique_id;
+struct mdesc_mem_ops {
+        struct mdesc_handle *(*alloc)(unsigned int mdesc_size);
+        void (*free)(struct mdesc_handle *handle);
+};
 
-static struct mdesc_node **mdesc_hash;
-static unsigned int mdesc_hash_size;
+struct mdesc_handle {
+        struct list_head        list;
+        struct mdesc_mem_ops    *mops;
+        void                    *self_base;
+        atomic_t                refcnt;
+        unsigned int            handle_size;
+        struct mdesc_hdr        mdesc;
+};
 
-static inline unsigned int node_hashfn(u64 node)
+static void mdesc_handle_init(struct mdesc_handle *hp,
+                              unsigned int handle_size,
+                              void *base)
 {
-        return ((unsigned int) (node ^ (node >> 8) ^ (node >> 16)))
-                & (mdesc_hash_size - 1);
+        BUG_ON(((unsigned long)&hp->mdesc) & (16UL - 1));
+
+        memset(hp, 0, handle_size);
+        INIT_LIST_HEAD(&hp->list);
+        hp->self_base = base;
+        atomic_set(&hp->refcnt, 1);
+        hp->handle_size = handle_size;
 }
 
-static inline void hash_node(struct mdesc_node *mp)
+static struct mdesc_handle *mdesc_bootmem_alloc(unsigned int mdesc_size)
 {
-        struct mdesc_node **head = &mdesc_hash[node_hashfn(mp->node)];
+        struct mdesc_handle *hp;
+        unsigned int handle_size, alloc_size;
 
-        mp->hash_next = *head;
-        *head = mp;
+        handle_size = (sizeof(struct mdesc_handle) -
+                       sizeof(struct mdesc_hdr) +
+                       mdesc_size);
+        alloc_size = PAGE_ALIGN(handle_size);
 
-        if (allnodes_tail) {
-                allnodes_tail->allnodes_next = mp;
-                allnodes_tail = mp;
-        } else {
-                allnodes = allnodes_tail = mp;
-        }
+        hp = __alloc_bootmem(alloc_size, PAGE_SIZE, 0UL);
+        if (hp)
+                mdesc_handle_init(hp, handle_size, hp);
+
+        return hp;
 }
 
-static struct mdesc_node *find_node(u64 node)
+static void mdesc_bootmem_free(struct mdesc_handle *hp)
 {
-        struct mdesc_node *mp = mdesc_hash[node_hashfn(node)];
+        unsigned int alloc_size, handle_size = hp->handle_size;
+        unsigned long start, end;
 
-        while (mp) {
-                if (mp->node == node)
-                        return mp;
+        BUG_ON(atomic_read(&hp->refcnt) != 0);
+        BUG_ON(!list_empty(&hp->list));
 
-                mp = mp->hash_next;
+        alloc_size = PAGE_ALIGN(handle_size);
+
+        start = (unsigned long) hp;
+        end = start + alloc_size;
+
+        while (start < end) {
+                struct page *p;
+
+                p = virt_to_page(start);
+                ClearPageReserved(p);
+                __free_page(p);
+                start += PAGE_SIZE;
         }
-        return NULL;
 }
 
-struct property *md_find_property(const struct mdesc_node *mp,
-                                  const char *name,
-                                  int *lenp)
+static struct mdesc_mem_ops bootmem_mdesc_memops = {
+        .alloc = mdesc_bootmem_alloc,
+        .free  = mdesc_bootmem_free,
+};
+
+static struct mdesc_handle *mdesc_kmalloc(unsigned int mdesc_size)
 {
-        struct property *pp;
+        unsigned int handle_size;
+        void *base;
 
-        for (pp = mp->properties; pp != 0; pp = pp->next) {
-                if (strcasecmp(pp->name, name) == 0) {
-                        if (lenp)
-                                *lenp = pp->length;
-                        break;
-                }
+        handle_size = (sizeof(struct mdesc_handle) -
+                       sizeof(struct mdesc_hdr) +
+                       mdesc_size);
+
+        base = kmalloc(handle_size + 15, GFP_KERNEL);
+        if (base) {
+                struct mdesc_handle *hp;
+                unsigned long addr;
+
+                addr = (unsigned long)base;
+                addr = (addr + 15UL) & ~15UL;
+                hp = (struct mdesc_handle *) addr;
+
+                mdesc_handle_init(hp, handle_size, base);
+                return hp;
         }
-        return pp;
+
+        return NULL;
 }
-EXPORT_SYMBOL(md_find_property);
 
-/*
- * Find a property with a given name for a given node
- * and return the value.
- */
-const void *md_get_property(const struct mdesc_node *mp, const char *name,
-                            int *lenp)
+static void mdesc_kfree(struct mdesc_handle *hp)
 {
-        struct property *pp = md_find_property(mp, name, lenp);
-        return pp ? pp->value : NULL;
+        BUG_ON(atomic_read(&hp->refcnt) != 0);
+        BUG_ON(!list_empty(&hp->list));
+
+        kfree(hp->self_base);
 }
-EXPORT_SYMBOL(md_get_property);
 
-struct mdesc_node *md_find_node_by_name(struct mdesc_node *from,
-                                        const char *name)
+static struct mdesc_mem_ops kmalloc_mdesc_memops = {
+        .alloc = mdesc_kmalloc,
+        .free  = mdesc_kfree,
+};
+
+static struct mdesc_handle *mdesc_alloc(unsigned int mdesc_size,
+                                        struct mdesc_mem_ops *mops)
 {
-        struct mdesc_node *mp;
+        struct mdesc_handle *hp = mops->alloc(mdesc_size);
 
-        mp = from ? from->allnodes_next : allnodes;
-        for (; mp != NULL; mp = mp->allnodes_next) {
-                if (strcmp(mp->name, name) == 0)
-                        break;
-        }
-        return mp;
-}
-EXPORT_SYMBOL(md_find_node_by_name);
+        if (hp)
+                hp->mops = mops;
 
-static unsigned int mdesc_early_allocated;
+        return hp;
+}
 
-static void * __init mdesc_early_alloc(unsigned long size)
+static void mdesc_free(struct mdesc_handle *hp)
 {
-        void *ret;
+        hp->mops->free(hp);
+}
 
-        ret = __alloc_bootmem(size, SMP_CACHE_BYTES, 0UL);
-        if (ret == NULL) {
-                prom_printf("MDESC: alloc of %lu bytes failed.\n", size);
-                prom_halt();
-        }
+static struct mdesc_handle *cur_mdesc;
+static LIST_HEAD(mdesc_zombie_list);
+static DEFINE_SPINLOCK(mdesc_lock);
 
-        memset(ret, 0, size);
+struct mdesc_handle *mdesc_grab(void)
+{
+        struct mdesc_handle *hp;
+        unsigned long flags;
 
-        mdesc_early_allocated += size;
+        spin_lock_irqsave(&mdesc_lock, flags);
+        hp = cur_mdesc;
+        if (hp)
+                atomic_inc(&hp->refcnt);
+        spin_unlock_irqrestore(&mdesc_lock, flags);
 
-        return ret;
+        return hp;
 }
+EXPORT_SYMBOL(mdesc_grab);
 
-static unsigned int __init count_arcs(struct mdesc_elem *ep)
+void mdesc_release(struct mdesc_handle *hp)
 {
-        unsigned int ret = 0;
+        unsigned long flags;
 
-        ep++;
-        while (ep->tag != MD_NODE_END) {
-                if (ep->tag == MD_PROP_ARC)
-                        ret++;
-                ep++;
+        spin_lock_irqsave(&mdesc_lock, flags);
+        if (atomic_dec_and_test(&hp->refcnt)) {
+                list_del_init(&hp->list);
+                hp->mops->free(hp);
         }
-        return ret;
+        spin_unlock_irqrestore(&mdesc_lock, flags);
 }
+EXPORT_SYMBOL(mdesc_release);
 
-static void __init mdesc_node_alloc(u64 node, struct mdesc_elem *ep, const char *names)
+static void do_mdesc_update(struct work_struct *work)
 {
-        unsigned int num_arcs = count_arcs(ep);
-        struct mdesc_node *mp;
+        unsigned long len, real_len, status;
+        struct mdesc_handle *hp, *orig_hp;
+        unsigned long flags;
+
+        (void) sun4v_mach_desc(0UL, 0UL, &len);
+
+        hp = mdesc_alloc(len, &kmalloc_mdesc_memops);
+        if (!hp) {
+                printk(KERN_ERR "MD: mdesc alloc fails\n");
+                return;
+        }
+
+        status = sun4v_mach_desc(__pa(&hp->mdesc), len, &real_len);
+        if (status != HV_EOK || real_len > len) {
+                printk(KERN_ERR "MD: mdesc reread fails with %lu\n",
+                       status);
+                atomic_dec(&hp->refcnt);
+                mdesc_free(hp);
+                return;
+        }
 
-        mp = mdesc_early_alloc(sizeof(*mp) +
-                               (num_arcs * sizeof(struct mdesc_arc)));
-        mp->name = names + ep->name_offset;
-        mp->node = node;
-        mp->unique_id = unique_id++;
-        mp->num_arcs = num_arcs;
+        spin_lock_irqsave(&mdesc_lock, flags);
+        orig_hp = cur_mdesc;
+        cur_mdesc = hp;
 
-        hash_node(mp);
+        if (atomic_dec_and_test(&orig_hp->refcnt))
+                mdesc_free(orig_hp);
+        else
+                list_add(&orig_hp->list, &mdesc_zombie_list);
+        spin_unlock_irqrestore(&mdesc_lock, flags);
 }
 
-static inline struct mdesc_elem *node_block(struct mdesc_hdr *mdesc)
+static DECLARE_WORK(mdesc_update_work, do_mdesc_update);
+
+void mdesc_update(void)
+{
+        schedule_work(&mdesc_update_work);
+}
+
+static struct mdesc_elem *node_block(struct mdesc_hdr *mdesc)
 {
         return (struct mdesc_elem *) (mdesc + 1);
 }
 
-static inline void *name_block(struct mdesc_hdr *mdesc)
+static void *name_block(struct mdesc_hdr *mdesc)
 {
         return ((void *) node_block(mdesc)) + mdesc->node_sz;
 }
 
-static inline void *data_block(struct mdesc_hdr *mdesc)
+static void *data_block(struct mdesc_hdr *mdesc)
 {
         return ((void *) name_block(mdesc)) + mdesc->name_sz;
 }
 
-/* In order to avoid recursion (the graph can be very deep) we use a
- * two pass algorithm.  First we allocate all the nodes and hash them.
- * Then we iterate over each node, filling in the arcs and properties.
- */
-static void __init build_all_nodes(struct mdesc_hdr *mdesc)
+u64 mdesc_node_by_name(struct mdesc_handle *hp,
+                       u64 from_node, const char *name)
 {
-        struct mdesc_elem *start, *ep;
-        struct mdesc_node *mp;
-        const char *names;
-        void *data;
-        u64 last_node;
-
-        start = ep = node_block(mdesc);
-        last_node = mdesc->node_sz / 16;
+        struct mdesc_elem *ep = node_block(&hp->mdesc);
+        const char *names = name_block(&hp->mdesc);
+        u64 last_node = hp->mdesc.node_sz / 16;
+        u64 ret;
+
+        if (from_node == MDESC_NODE_NULL)
+                from_node = 0;
+
+        if (from_node >= last_node)
+                return MDESC_NODE_NULL;
+
+        ret = ep[from_node].d.val;
+        while (ret < last_node) {
+                if (ep[ret].tag != MD_NODE)
+                        return MDESC_NODE_NULL;
+                if (!strcmp(names + ep[ret].name_offset, name))
+                        break;
+                ret = ep[ret].d.val;
+        }
+        if (ret >= last_node)
+                ret = MDESC_NODE_NULL;
+        return ret;
+}
+EXPORT_SYMBOL(mdesc_node_by_name);
 
-        names = name_block(mdesc);
+const void *mdesc_get_property(struct mdesc_handle *hp, u64 node,
+                               const char *name, int *lenp)
+{
+        const char *names = name_block(&hp->mdesc);
+        u64 last_node = hp->mdesc.node_sz / 16;
+        void *data = data_block(&hp->mdesc);
+        struct mdesc_elem *ep;
 
-        while (1) {
-                u64 node = ep - start;
+        if (node == MDESC_NODE_NULL || node >= last_node)
+                return NULL;
 
-                if (ep->tag == MD_LIST_END)
+        ep = node_block(&hp->mdesc) + node;
+        ep++;
+        for (; ep->tag != MD_NODE_END; ep++) {
+                void *val = NULL;
+                int len = 0;
+
+                switch (ep->tag) {
+                case MD_PROP_VAL:
+                        val = &ep->d.val;
+                        len = 8;
                         break;
 
-                if (ep->tag != MD_NODE) {
-                        prom_printf("MDESC: Inconsistent element list.\n");
-                        prom_halt();
-                }
-
-                mdesc_node_alloc(node, ep, names);
+                case MD_PROP_STR:
+                case MD_PROP_DATA:
+                        val = data + ep->d.data.data_offset;
+                        len = ep->d.data.data_len;
+                        break;
 
-                if (ep->d.val >= last_node) {
-                        printk("MDESC: Warning, early break out of node scan.\n");
-                        printk("MDESC: Next node [%lu] last_node [%lu].\n",
-                               node, last_node);
+                default:
                         break;
                 }
+                if (!val)
+                        continue;
 
-                ep = start + ep->d.val;
+                if (!strcmp(names + ep->name_offset, name)) {
+                        if (lenp)
+                                *lenp = len;
+                        return val;
+                }
         }
 
-        data = data_block(mdesc);
-        for (mp = allnodes; mp; mp = mp->allnodes_next) {
-                struct mdesc_elem *ep = start + mp->node;
-                struct property **link = &mp->properties;
-                unsigned int this_arc = 0;
-
-                ep++;
-                while (ep->tag != MD_NODE_END) {
-                        switch (ep->tag) {
-                        case MD_PROP_ARC: {
-                                struct mdesc_node *target;
-
-                                if (this_arc >= mp->num_arcs) {
-                                        prom_printf("MDESC: ARC overrun [%u:%u]\n",
-                                                    this_arc, mp->num_arcs);
-                                        prom_halt();
-                                }
-                                target = find_node(ep->d.val);
-                                if (!target) {
-                                        printk("MDESC: Warning, arc points to "
-                                               "missing node, ignoring.\n");
-                                        break;
-                                }
-                                mp->arcs[this_arc].name =
-                                        (names + ep->name_offset);
-                                mp->arcs[this_arc].arc = target;
-                                this_arc++;
-                                break;
-                        }
+        return NULL;
+}
+EXPORT_SYMBOL(mdesc_get_property);
 
-                        case MD_PROP_VAL:
-                        case MD_PROP_STR:
-                        case MD_PROP_DATA: {
-                                struct property *p = mdesc_early_alloc(sizeof(*p));
-
-                                p->unique_id = unique_id++;
-                                p->name = (char *) names + ep->name_offset;
-                                if (ep->tag == MD_PROP_VAL) {
-                                        p->value = &ep->d.val;
-                                        p->length = 8;
-                                } else {
-                                        p->value = data + ep->d.data.data_offset;
-                                        p->length = ep->d.data.data_len;
-                                }
-                                *link = p;
-                                link = &p->next;
-                                break;
-                        }
+u64 mdesc_next_arc(struct mdesc_handle *hp, u64 from, const char *arc_type)
+{
+        struct mdesc_elem *ep, *base = node_block(&hp->mdesc);
+        const char *names = name_block(&hp->mdesc);
+        u64 last_node = hp->mdesc.node_sz / 16;
 
-                        case MD_NOOP:
-                                break;
+        if (from == MDESC_NODE_NULL || from >= last_node)
+                return MDESC_NODE_NULL;
 
-                        default:
-                                printk("MDESC: Warning, ignoring unknown tag type %02x\n",
-                                       ep->tag);
-                        }
-                        ep++;
-                }
+        ep = base + from;
+
+        ep++;
+        for (; ep->tag != MD_NODE_END; ep++) {
+                if (ep->tag != MD_PROP_ARC)
+                        continue;
+
+                if (strcmp(names + ep->name_offset, arc_type))
+                        continue;
+
+                return ep - base;
         }
+
+        return MDESC_NODE_NULL;
 }
+EXPORT_SYMBOL(mdesc_next_arc);
 
-static unsigned int __init count_nodes(struct mdesc_hdr *mdesc)
+u64 mdesc_arc_target(struct mdesc_handle *hp, u64 arc)
 {
-        struct mdesc_elem *ep = node_block(mdesc);
-        struct mdesc_elem *end;
-        unsigned int cnt = 0;
-
-        end = ((void *)ep) + mdesc->node_sz;
-        while (ep < end) {
-                if (ep->tag == MD_NODE)
-                        cnt++;
-                ep++;
-        }
-        return cnt;
+        struct mdesc_elem *ep, *base = node_block(&hp->mdesc);
+
+        ep = base + arc;
+
+        return ep->d.val;
 }
+EXPORT_SYMBOL(mdesc_arc_target);
+
+const char *mdesc_node_name(struct mdesc_handle *hp, u64 node)
+{
+        struct mdesc_elem *ep, *base = node_block(&hp->mdesc);
+        const char *names = name_block(&hp->mdesc);
+        u64 last_node = hp->mdesc.node_sz / 16;
+
+        if (node == MDESC_NODE_NULL || node >= last_node)
+                return NULL;
+
+        ep = base + node;
+        if (ep->tag != MD_NODE)
+                return NULL;
+
+        return names + ep->name_offset;
+}
+EXPORT_SYMBOL(mdesc_node_name);
 
 static void __init report_platform_properties(void)
 {
-        struct mdesc_node *pn = md_find_node_by_name(NULL, "platform");
+        struct mdesc_handle *hp = mdesc_grab();
+        u64 pn = mdesc_node_by_name(hp, MDESC_NODE_NULL, "platform");
         const char *s;
         const u64 *v;
 
-        if (!pn) {
+        if (pn == MDESC_NODE_NULL) {
                 prom_printf("No platform node in machine-description.\n");
                 prom_halt();
         }
 
-        s = md_get_property(pn, "banner-name", NULL);
+        s = mdesc_get_property(hp, pn, "banner-name", NULL);
         printk("PLATFORM: banner-name [%s]\n", s);
-        s = md_get_property(pn, "name", NULL);
+        s = mdesc_get_property(hp, pn, "name", NULL);
         printk("PLATFORM: name [%s]\n", s);
 
-        v = md_get_property(pn, "hostid", NULL);
+        v = mdesc_get_property(hp, pn, "hostid", NULL);
         if (v)
                 printk("PLATFORM: hostid [%08lx]\n", *v);
-        v = md_get_property(pn, "serial#", NULL);
+        v = mdesc_get_property(hp, pn, "serial#", NULL);
         if (v)
                 printk("PLATFORM: serial# [%08lx]\n", *v);
-        v = md_get_property(pn, "stick-frequency", NULL);
+        v = mdesc_get_property(hp, pn, "stick-frequency", NULL);
         printk("PLATFORM: stick-frequency [%08lx]\n", *v);
-        v = md_get_property(pn, "mac-address", NULL);
+        v = mdesc_get_property(hp, pn, "mac-address", NULL);
         if (v)
                 printk("PLATFORM: mac-address [%lx]\n", *v);
-        v = md_get_property(pn, "watchdog-resolution", NULL);
+        v = mdesc_get_property(hp, pn, "watchdog-resolution", NULL);
         if (v)
                 printk("PLATFORM: watchdog-resolution [%lu ms]\n", *v);
-        v = md_get_property(pn, "watchdog-max-timeout", NULL);
+        v = mdesc_get_property(hp, pn, "watchdog-max-timeout", NULL);
         if (v)
                 printk("PLATFORM: watchdog-max-timeout [%lu ms]\n", *v);
-        v = md_get_property(pn, "max-cpus", NULL);
+        v = mdesc_get_property(hp, pn, "max-cpus", NULL);
         if (v)
                 printk("PLATFORM: max-cpus [%lu]\n", *v);
+
+        mdesc_release(hp);
 }
 
 static int inline find_in_proplist(const char *list, const char *match, int len)
@@ -369,15 +451,17 @@ 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_node *mp)
+static void __init fill_in_one_cache(cpuinfo_sparc *c,
+                                     struct mdesc_handle *hp,
+                                     u64 mp)
 {
-        const u64 *level = md_get_property(mp, "level", NULL);
-        const u64 *size = md_get_property(mp, "size", NULL);
-        const u64 *line_size = md_get_property(mp, "line-size", NULL);
+        const u64 *level = mdesc_get_property(hp, mp, "level", NULL);
+        const u64 *size = mdesc_get_property(hp, mp, "size", NULL);
+        const u64 *line_size = mdesc_get_property(hp, mp, "line-size", NULL);
         const char *type;
         int type_len;
 
-        type = md_get_property(mp, "type", &type_len);
+        type = mdesc_get_property(hp, mp, "type", &type_len);
 
         switch (*level) {
         case 1:
@@ -400,48 +484,44 @@ static void __init fill_in_one_cache(cpuinfo_sparc *c, struct mdesc_node *mp)
         }
 
         if (*level == 1) {
-                unsigned int i;
+                u64 a;
 
-                for (i = 0; i < mp->num_arcs; i++) {
-                        struct mdesc_node *t = mp->arcs[i].arc;
+                mdesc_for_each_arc(a, hp, mp, MDESC_ARC_TYPE_FWD) {
+                        u64 target = mdesc_arc_target(hp, a);
+                        const char *name = mdesc_node_name(hp, target);
 
-                        if (strcmp(mp->arcs[i].name, "fwd"))
-                                continue;
-
-                        if (!strcmp(t->name, "cache"))
-                                fill_in_one_cache(c, t);
+                        if (!strcmp(name, "cache"))
+                                fill_in_one_cache(c, hp, target);
                 }
         }
 }
 
-static void __init mark_core_ids(struct mdesc_node *mp, int core_id)
+static void __init mark_core_ids(struct mdesc_handle *hp, u64 mp, int core_id)
 {
-        unsigned int i;
+        u64 a;
 
-        for (i = 0; i < mp->num_arcs; i++) {
-                struct mdesc_node *t = mp->arcs[i].arc;
+        mdesc_for_each_arc(a, hp, mp, MDESC_ARC_TYPE_BACK) {
+                u64 t = mdesc_arc_target(hp, a);
+                const char *name;
                 const u64 *id;
 
-                if (strcmp(mp->arcs[i].name, "back"))
-                        continue;
-
-                if (!strcmp(t->name, "cpu")) {
-                        id = md_get_property(t, "id", NULL);
+                name = mdesc_node_name(hp, t);
+                if (!strcmp(name, "cpu")) {
+                        id = mdesc_get_property(hp, t, "id", NULL);
                         if (*id < NR_CPUS)
                                 cpu_data(*id).core_id = core_id;
                 } else {
-                        unsigned int j;
+                        u64 j;
 
-                        for (j = 0; j < t->num_arcs; j++) {
-                                struct mdesc_node *n = t->arcs[j].arc;
+                        mdesc_for_each_arc(j, hp, t, MDESC_ARC_TYPE_BACK) {
+                                u64 n = mdesc_arc_target(hp, j);
+                                const char *n_name;
 
-                                if (strcmp(t->arcs[j].name, "back"))
+                                n_name = mdesc_node_name(hp, n);
+                                if (strcmp(n_name, "cpu"))
                                         continue;
 
-                                if (strcmp(n->name, "cpu"))
-                                        continue;
-
-                                id = md_get_property(n, "id", NULL);
+                                id = mdesc_get_property(hp, n, "id", NULL);
                                 if (*id < NR_CPUS)
                                         cpu_data(*id).core_id = core_id;
                         }
@@ -449,75 +529,76 @@ static void __init mark_core_ids(struct mdesc_node *mp, int core_id)
         }
 }
 
-static void __init set_core_ids(void)
+static void __init set_core_ids(struct mdesc_handle *hp)
 {
-        struct mdesc_node *mp;
         int idx;
+        u64 mp;
 
         idx = 1;
-        md_for_each_node_by_name(mp, "cache") {
-                const u64 *level = md_get_property(mp, "level", NULL);
+        mdesc_for_each_node_by_name(hp, mp, "cache") {
+                const u64 *level;
                 const char *type;
                 int len;
 
+                level = mdesc_get_property(hp, mp, "level", NULL);
                 if (*level != 1)
                         continue;
 
-                type = md_get_property(mp, "type", &len);
+                type = mdesc_get_property(hp, mp, "type", &len);
                 if (!find_in_proplist(type, "instn", len))
                         continue;
 
-                mark_core_ids(mp, idx);
+                mark_core_ids(hp, mp, idx);
 
                 idx++;
         }
 }
 
-static void __init mark_proc_ids(struct mdesc_node *mp, int proc_id)
+static void __init mark_proc_ids(struct mdesc_handle *hp, u64 mp, int proc_id)
 {
-        int i;
+        u64 a;
 
-        for (i = 0; i < mp->num_arcs; i++) {
-                struct mdesc_node *t = mp->arcs[i].arc;
+        mdesc_for_each_arc(a, hp, mp, MDESC_ARC_TYPE_BACK) {
+                u64 t = mdesc_arc_target(hp, a);
+                const char *name;
                 const u64 *id;
 
-                if (strcmp(mp->arcs[i].name, "back"))
-                        continue;
-
-                if (strcmp(t->name, "cpu"))
+                name = mdesc_node_name(hp, t);
+                if (strcmp(name, "cpu"))
                         continue;
 
-                id = md_get_property(t, "id", NULL);
+                id = mdesc_get_property(hp, t, "id", NULL);
                 if (*id < NR_CPUS)
                         cpu_data(*id).proc_id = proc_id;
         }
 }
 
-static void __init __set_proc_ids(const char *exec_unit_name)
+static void __init __set_proc_ids(struct mdesc_handle *hp,
+                                  const char *exec_unit_name)
 {
-        struct mdesc_node *mp;
         int idx;
+        u64 mp;
 
         idx = 0;
-        md_for_each_node_by_name(mp, exec_unit_name) {
+        mdesc_for_each_node_by_name(hp, mp, exec_unit_name) {
                 const char *type;
                 int len;
 
-                type = md_get_property(mp, "type", &len);
+                type = mdesc_get_property(hp, mp, "type", &len);
                 if (!find_in_proplist(type, "int", len) &&
                     !find_in_proplist(type, "integer", len))
                         continue;
 
-                mark_proc_ids(mp, idx);
+                mark_proc_ids(hp, mp, idx);
 
                 idx++;
         }
 }
 
-static void __init set_proc_ids(void)
+static void __init set_proc_ids(struct mdesc_handle *hp)
 {
-        __set_proc_ids("exec_unit");
-        __set_proc_ids("exec-unit");
+        __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)
@@ -538,35 +619,37 @@ use_default:
         *mask = ((1U << def) * 64U) - 1U;
 }
 
-static void __init get_mondo_data(struct mdesc_node *mp, struct trap_per_cpu *tb)
+static void __init get_mondo_data(struct mdesc_handle *hp, u64 mp,
+                                  struct trap_per_cpu *tb)
 {
         const u64 *val;
 
-        val = md_get_property(mp, "q-cpu-mondo-#bits", NULL);
+        val = mdesc_get_property(hp, mp, "q-cpu-mondo-#bits", NULL);
         get_one_mondo_bits(val, &tb->cpu_mondo_qmask, 7);
 
-        val = md_get_property(mp, "q-dev-mondo-#bits", NULL);
+        val = mdesc_get_property(hp, mp, "q-dev-mondo-#bits", NULL);
         get_one_mondo_bits(val, &tb->dev_mondo_qmask, 7);
 
-        val = md_get_property(mp, "q-resumable-#bits", NULL);
+        val = mdesc_get_property(hp, mp, "q-resumable-#bits", NULL);
         get_one_mondo_bits(val, &tb->resum_qmask, 6);
 
-        val = md_get_property(mp, "q-nonresumable-#bits", NULL);
+        val = mdesc_get_property(hp, mp, "q-nonresumable-#bits", NULL);
         get_one_mondo_bits(val, &tb->nonresum_qmask, 2);
 }
 
 static void __init mdesc_fill_in_cpu_data(void)
 {
-        struct mdesc_node *mp;
+        struct mdesc_handle *hp = mdesc_grab();
+        u64 mp;
 
         ncpus_probed = 0;
-        md_for_each_node_by_name(mp, "cpu") {
-                const u64 *id = md_get_property(mp, "id", NULL);
-                const u64 *cfreq = md_get_property(mp, "clock-frequency", NULL);
+        mdesc_for_each_node_by_name(hp, mp, "cpu") {
+                const u64 *id = mdesc_get_property(hp, mp, "id", NULL);
+                const u64 *cfreq = mdesc_get_property(hp, mp, "clock-frequency", NULL);
                 struct trap_per_cpu *tb;
                 cpuinfo_sparc *c;
-                unsigned int i;
                 int cpuid;
+                u64 a;
 
                 ncpus_probed++;
 
@@ -589,29 +672,25 @@ static void __init mdesc_fill_in_cpu_data(void)
                 c->clock_tick = *cfreq;
 
                 tb = &trap_block[cpuid];
-                get_mondo_data(mp, tb);
-
-                for (i = 0; i < mp->num_arcs; i++) {
-                        struct mdesc_node *t = mp->arcs[i].arc;
-                        unsigned int j;
+                get_mondo_data(hp, mp, tb);
 
-                        if (strcmp(mp->arcs[i].name, "fwd"))
-                                continue;
+                mdesc_for_each_arc(a, hp, mp, MDESC_ARC_TYPE_FWD) {
+                        u64 j, t = mdesc_arc_target(hp, a);
+                        const char *t_name;
 
-                        if (!strcmp(t->name, "cache")) {
-                                fill_in_one_cache(c, t);
+                        t_name = mdesc_node_name(hp, t);
+                        if (!strcmp(t_name, "cache")) {
+                                fill_in_one_cache(c, hp, t);
                                 continue;
                         }
 
-                        for (j = 0; j < t->num_arcs; j++) {
-                                struct mdesc_node *n;
+                        mdesc_for_each_arc(j, hp, t, MDESC_ARC_TYPE_FWD) {
+                                u64 n = mdesc_arc_target(hp, j);
+                                const char *n_name;
 
-                                n = t->arcs[j].arc;
-                                if (strcmp(t->arcs[j].name, "fwd"))
-                                        continue;
-
-                                if (!strcmp(n->name, "cache"))
-                                        fill_in_one_cache(c, n);
+                                n_name = mdesc_node_name(hp, n);
+                                if (!strcmp(n_name, "cache"))
+                                        fill_in_one_cache(c, hp, n);
                         }
                 }
 
@@ -628,44 +707,39 @@ static void __init mdesc_fill_in_cpu_data(void)
         sparc64_multi_core = 1;
 #endif
 
-        set_core_ids();
-        set_proc_ids();
+        set_core_ids(hp);
+        set_proc_ids(hp);
 
         smp_fill_in_sib_core_maps();
+
+        mdesc_release(hp);
 }
 
 void __init sun4v_mdesc_init(void)
 {
+        struct mdesc_handle *hp;
         unsigned long len, real_len, status;
 
         (void) sun4v_mach_desc(0UL, 0UL, &len);
 
         printk("MDESC: Size is %lu bytes.\n", len);
 
-        main_mdesc = mdesc_early_alloc(len);
+        hp = mdesc_alloc(len, &bootmem_mdesc_memops);
+        if (hp == NULL) {
+                prom_printf("MDESC: alloc of %lu bytes failed.\n", len);
+                prom_halt();
+        }
 
-        status = sun4v_mach_desc(__pa(main_mdesc), len, &real_len);
+        status = sun4v_mach_desc(__pa(&hp->mdesc), len, &real_len);
         if (status != HV_EOK || real_len > len) {
                 prom_printf("sun4v_mach_desc fails, err(%lu), "
                             "len(%lu), real_len(%lu)\n",
                             status, len, real_len);
+                mdesc_free(hp);
                 prom_halt();
         }
 
-        len = count_nodes(main_mdesc);
-        printk("MDESC: %lu nodes.\n", len);
-
-        len = roundup_pow_of_two(len);
-
-        mdesc_hash = mdesc_early_alloc(len * sizeof(struct mdesc_node *));
-        mdesc_hash_size = len;
-
-        printk("MDESC: Hash size %lu entries.\n", len);
-
-        build_all_nodes(main_mdesc);
-
-        printk("MDESC: Built graph with %u bytes of memory.\n",
-               mdesc_early_allocated);
+        cur_mdesc = hp;
 
         report_platform_properties();
         mdesc_fill_in_cpu_data();
diff --git a/arch/sparc64/kernel/vio.c b/arch/sparc64/kernel/vio.c
index 7eccc91cd59d..64f082555bcd 100644
--- a/arch/sparc64/kernel/vio.c
+++ b/arch/sparc64/kernel/vio.c
@@ -147,30 +147,6 @@ void vio_unregister_driver(struct vio_driver *viodrv)
 }
 EXPORT_SYMBOL(vio_unregister_driver);
 
-struct mdesc_node *vio_find_endpoint(struct vio_dev *vdev)
-{
-        struct mdesc_node *endp, *mp = vdev->mp;
-        int i;
-
-        endp = NULL;
-        for (i = 0; i < mp->num_arcs; i++) {
-                struct mdesc_node *t;
-
-                if (strcmp(mp->arcs[i].name, "fwd"))
-                        continue;
-
-                t = mp->arcs[i].arc;
-                if (strcmp(t->name, "channel-endpoint"))
-                        continue;
-
-                endp = t;
-                break;
-        }
-
-        return endp;
-}
-EXPORT_SYMBOL(vio_find_endpoint);
-
 static void __devinit vio_dev_release(struct device *dev)
 {
         kfree(to_vio_dev(dev));
@@ -197,22 +173,47 @@ struct device_node *cdev_node;
 static struct vio_dev *root_vdev;
 static u64 cdev_cfg_handle;
 
-static struct vio_dev *vio_create_one(struct mdesc_node *mp,
+static void vio_fill_channel_info(struct mdesc_handle *hp, u64 mp,
+                                  struct vio_dev *vdev)
+{
+        u64 a;
+
+        mdesc_for_each_arc(a, hp, mp, MDESC_ARC_TYPE_FWD) {
+                const u64 *chan_id;
+                const u64 *irq;
+                u64 target;
+
+                target = mdesc_arc_target(hp, a);
+
+                irq = mdesc_get_property(hp, target, "tx-ino", NULL);
+                if (irq)
+                        vdev->tx_irq = sun4v_build_virq(cdev_cfg_handle, *irq);
+
+                irq = mdesc_get_property(hp, target, "rx-ino", NULL);
+                if (irq)
+                        vdev->rx_irq = sun4v_build_virq(cdev_cfg_handle, *irq);
+
+                chan_id = mdesc_get_property(hp, target, "id", NULL);
+                if (chan_id)
+                        vdev->channel_id = *chan_id;
+        }
+}
+
+static struct vio_dev *vio_create_one(struct mdesc_handle *hp, u64 mp,
                                       struct device *parent)
 {
         const char *type, *compat;
         struct device_node *dp;
         struct vio_dev *vdev;
-        const u64 *irq;
         int err, clen;
 
-        type = md_get_property(mp, "device-type", NULL);
+        type = mdesc_get_property(hp, mp, "device-type", NULL);
         if (!type) {
-                type = md_get_property(mp, "name", NULL);
+                type = mdesc_get_property(hp, mp, "name", NULL);
                 if (!type)
-                        type = mp->name;
+                        type = mdesc_node_name(hp, mp);
         }
-        compat = md_get_property(mp, "device-type", &clen);
+        compat = mdesc_get_property(hp, mp, "device-type", &clen);
 
         vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
         if (!vdev) {
@@ -225,15 +226,13 @@ static struct vio_dev *vio_create_one(struct mdesc_node *mp,
         vdev->compat = compat;
         vdev->compat_len = clen;
 
-        irq = md_get_property(mp, "tx-ino", NULL);
-        if (irq)
-                mp->irqs[0] = sun4v_build_virq(cdev_cfg_handle, *irq);
+        vdev->channel_id = ~0UL;
+        vdev->tx_irq = ~0;
+        vdev->rx_irq = ~0;
 
-        irq = md_get_property(mp, "rx-ino", NULL);
-        if (irq)
-                mp->irqs[1] = sun4v_build_virq(cdev_cfg_handle, *irq);
+        vio_fill_channel_info(hp, mp, vdev);
 
-        snprintf(vdev->dev.bus_id, BUS_ID_SIZE, "%lx", mp->node);
+        snprintf(vdev->dev.bus_id, BUS_ID_SIZE, "%lx", mp);
         vdev->dev.parent = parent;
         vdev->dev.bus = &vio_bus_type;
         vdev->dev.release = vio_dev_release;
@@ -267,46 +266,43 @@ static struct vio_dev *vio_create_one(struct mdesc_node *mp,
         return vdev;
 }
 
-static void walk_tree(struct mdesc_node *n, struct vio_dev *parent)
+static void walk_tree(struct mdesc_handle *hp, u64 n, struct vio_dev *parent)
 {
-        int i;
+        u64 a;
 
-        for (i = 0; i < n->num_arcs; i++) {
-                struct mdesc_node *mp;
+        mdesc_for_each_arc(a, hp, n, MDESC_ARC_TYPE_FWD) {
                 struct vio_dev *vdev;
+                u64 target;
 
-                if (strcmp(n->arcs[i].name, "fwd"))
-                        continue;
-
-                mp = n->arcs[i].arc;
-
-                vdev = vio_create_one(mp, &parent->dev);
-                if (vdev && mp->num_arcs)
-                        walk_tree(mp, vdev);
+                target = mdesc_arc_target(hp, a);
+                vdev = vio_create_one(hp, target, &parent->dev);
+                if (vdev)
+                        walk_tree(hp, target, vdev);
         }
 }
 
-static void create_devices(struct mdesc_node *root)
+static void create_devices(struct mdesc_handle *hp, u64 root)
 {
-        struct mdesc_node *mp;
+        u64 mp;
 
-        root_vdev = vio_create_one(root, NULL);
+        root_vdev = vio_create_one(hp, root, NULL);
         if (!root_vdev) {
                 printk(KERN_ERR "VIO: Coult not create root device.\n");
                 return;
         }
 
-        walk_tree(root, root_vdev);
+        walk_tree(hp, root, root_vdev);
 
         /* Domain services is odd as it doesn't sit underneath the
          * channel-devices node, so we plug it in manually.
          */
-        mp = md_find_node_by_name(NULL, "domain-services");
-        if (mp) {
-                struct vio_dev *parent = vio_create_one(mp, &root_vdev->dev);
+        mp = mdesc_node_by_name(hp, MDESC_NODE_NULL, "domain-services");
+        if (mp != MDESC_NODE_NULL) {
+                struct vio_dev *parent = vio_create_one(hp, mp,
+                                                        &root_vdev->dev);
 
                 if (parent)
-                        walk_tree(mp, parent);
+                        walk_tree(hp, mp, parent);
         }
 }
 
@@ -316,40 +312,47 @@ const char *cfg_handle_prop = "cfg-handle";
 
 static int __init vio_init(void)
 {
-        struct mdesc_node *root;
+        struct mdesc_handle *hp;
         const char *compat;
         const u64 *cfg_handle;
         int err, len;
+        u64 root;
+
+        hp = mdesc_grab();
+        if (!hp)
+                return 0;
 
-        root = md_find_node_by_name(NULL, channel_devices_node);
-        if (!root) {
+        root = mdesc_node_by_name(hp, MDESC_NODE_NULL, channel_devices_node);
+        if (root == MDESC_NODE_NULL) {
                 printk(KERN_INFO "VIO: No channel-devices MDESC node.\n");
+                mdesc_release(hp);
                 return 0;
         }
 
         cdev_node = of_find_node_by_name(NULL, "channel-devices");
+        err = -ENODEV;
         if (!cdev_node) {
                 printk(KERN_INFO "VIO: No channel-devices OBP node.\n");
-                return -ENODEV;
+                goto out_release;
         }
 
-        compat = md_get_property(root, "compatible", &len);
+        compat = mdesc_get_property(hp, root, "compatible", &len);
         if (!compat) {
                 printk(KERN_ERR "VIO: Channel devices lacks compatible "
                        "property\n");
-                return -ENODEV;
+                goto out_release;
         }
         if (!find_in_proplist(compat, channel_devices_compat, len)) {
                 printk(KERN_ERR "VIO: Channel devices node lacks (%s) "
                        "compat entry.\n", channel_devices_compat);
-                return -ENODEV;
+                goto out_release;
         }
 
-        cfg_handle = md_get_property(root, cfg_handle_prop, NULL);
+        cfg_handle = mdesc_get_property(hp, root, cfg_handle_prop, NULL);
         if (!cfg_handle) {
                 printk(KERN_ERR "VIO: Channel devices lacks %s property\n",
                        cfg_handle_prop);
-                return -ENODEV;
+                goto out_release;
         }
 
         cdev_cfg_handle = *cfg_handle;
@@ -361,9 +364,15 @@ static int __init vio_init(void)
                 return err;
         }
 
-        create_devices(root);
+        create_devices(hp, root);
+
+        mdesc_release(hp);
 
         return 0;
+
+out_release:
+        mdesc_release(hp);
+        return err;
 }
 
 postcore_initcall(vio_init);
diff --git a/arch/sparc64/kernel/viohs.c b/arch/sparc64/kernel/viohs.c
index b0b1b8779342..15613add45d1 100644
--- a/arch/sparc64/kernel/viohs.c
+++ b/arch/sparc64/kernel/viohs.c
@@ -136,7 +136,7 @@ static int process_unknown(struct vio_driver_state *vio, void *arg)
                pkt->type, pkt->stype, pkt->stype_env, pkt->sid);
 
         printk(KERN_ERR "vio: ID[%lu] Resetting connection.\n",
-               vio->channel_id);
+               vio->vdev->channel_id);
 
         ldc_disconnect(vio->lp);
 
@@ -678,21 +678,11 @@ extern int vio_ldc_alloc(struct vio_driver_state *vio,
 {
         struct ldc_channel_config cfg = *base_cfg;
         struct ldc_channel *lp;
-        const u64 *id;
 
-        id = md_get_property(vio->endpoint, "id", NULL);
-        if (!id) {
-                printk(KERN_ERR "%s: Channel lacks id property.\n",
-                       vio->name);
-                return -ENODEV;
-        }
-
-        vio->channel_id = *id;
-
-        cfg.rx_irq = vio->rx_irq;
-        cfg.tx_irq = vio->tx_irq;
+        cfg.tx_irq = vio->vdev->tx_irq;
+        cfg.rx_irq = vio->vdev->rx_irq;
 
-        lp = ldc_alloc(vio->channel_id, &cfg, event_arg);
+        lp = ldc_alloc(vio->vdev->channel_id, &cfg, event_arg);
         if (IS_ERR(lp))
                 return PTR_ERR(lp);
 
@@ -728,7 +718,7 @@ void vio_port_up(struct vio_driver_state *vio)
                 if (err)
                         printk(KERN_WARNING "%s: Port %lu bind failed, "
                                "err=%d\n",
-                               vio->name, vio->channel_id, err);
+                               vio->name, vio->vdev->channel_id, err);
         }
 
         if (!err) {
@@ -736,7 +726,7 @@ void vio_port_up(struct vio_driver_state *vio)
                 if (err)
                         printk(KERN_WARNING "%s: Port %lu connect failed, "
                                "err=%d\n",
-                               vio->name, vio->channel_id, err);
+                               vio->name, vio->vdev->channel_id, err);
         }
         if (err) {
                 unsigned long expires = jiffies + HZ;
@@ -757,9 +747,9 @@ static void vio_port_timer(unsigned long _arg)
 }
 
 int vio_driver_init(struct vio_driver_state *vio, struct vio_dev *vdev,
-                    u8 dev_class, struct mdesc_node *channel_endpoint,
-                    struct vio_version *ver_table, int ver_table_size,
-                    struct vio_driver_ops *ops, char *name)
+                    u8 dev_class, struct vio_version *ver_table,
+                    int ver_table_size, struct vio_driver_ops *ops,
+                    char *name)
 {
         switch (dev_class) {
         case VDEV_NETWORK:
@@ -777,9 +767,6 @@ int vio_driver_init(struct vio_driver_state *vio, struct vio_dev *vdev,
             !ops->handshake_complete)
                 return -EINVAL;
 
-        if (!channel_endpoint)
-                return -EINVAL;
-
         if (!ver_table || ver_table_size < 0)
                 return -EINVAL;
 
@@ -793,10 +780,6 @@ int vio_driver_init(struct vio_driver_state *vio, struct vio_dev *vdev,
         vio->dev_class = dev_class;
         vio->vdev = vdev;
 
-        vio->endpoint = channel_endpoint;
-        vio->tx_irq = channel_endpoint->irqs[0];
-        vio->rx_irq = channel_endpoint->irqs[1];
-
         vio->ver_table = ver_table;
         vio->ver_table_entries = ver_table_size;
 
diff --git a/drivers/block/sunvdc.c b/drivers/block/sunvdc.c
index 8dbbeace52a1..0f5e3caf85d7 100644
--- a/drivers/block/sunvdc.c
+++ b/drivers/block/sunvdc.c
@@ -750,7 +750,7 @@ static struct vio_driver_ops vdc_vio_ops = {
 static int __devinit vdc_port_probe(struct vio_dev *vdev,
                                     const struct vio_device_id *id)
 {
-        struct mdesc_node *endp;
+        struct mdesc_handle *hp;
         struct vdc_port *port;
         unsigned long flags;
         struct vdc *vp;
@@ -763,26 +763,24 @@ static int __devinit vdc_port_probe(struct vio_dev *vdev,
                 return -ENODEV;
         }
 
-        endp = vio_find_endpoint(vdev);
-        if (!endp) {
-                printk(KERN_ERR PFX "Port lacks channel-endpoint.\n");
-                return -ENODEV;
-        }
+        hp = mdesc_grab();
 
-        port_id = md_get_property(vdev->mp, "id", NULL);
+        port_id = mdesc_get_property(hp, vdev->mp, "id", NULL);
+        err = -ENODEV;
         if (!port_id) {
                 printk(KERN_ERR PFX "Port lacks id property.\n");
-                return -ENODEV;
+                goto err_out_release_mdesc;
         }
         if ((*port_id << PARTITION_SHIFT) & ~(u64)MINORMASK) {
                 printk(KERN_ERR PFX "Port id [%lu] too large.\n", *port_id);
-                return -ENODEV;
+                goto err_out_release_mdesc;
         }
 
         port = kzalloc(sizeof(*port), GFP_KERNEL);
+        err = -ENOMEM;
         if (!port) {
                 printk(KERN_ERR PFX "Cannot allocate vdc_port.\n");
-                return -ENOMEM;
+                goto err_out_release_mdesc;
         }
 
         port->vp = vp;
@@ -797,7 +795,7 @@ static int __devinit vdc_port_probe(struct vio_dev *vdev,
                 snprintf(port->disk_name, sizeof(port->disk_name),
                          VDCBLK_NAME "%c", 'a' + (port->dev_no % 26));
 
-        err = vio_driver_init(&port->vio, vdev, VDEV_DISK, endp,
+        err = vio_driver_init(&port->vio, vdev, VDEV_DISK,
                               vdc_versions, ARRAY_SIZE(vdc_versions),
                               &vdc_vio_ops, port->disk_name);
         if (err)
@@ -828,6 +826,8 @@ static int __devinit vdc_port_probe(struct vio_dev *vdev,
 
         dev_set_drvdata(&vdev->dev, port);
 
+        mdesc_release(hp);
+
         return 0;
 
 err_out_free_tx_ring:
@@ -839,6 +839,8 @@ err_out_free_ldc:
 err_out_free_port:
         kfree(port);
 
+err_out_release_mdesc:
+        mdesc_release(hp);
         return err;
 }
 
diff --git a/drivers/net/sunvnet.c b/drivers/net/sunvnet.c
index d764e4ccba56..8a667c13faef 100644
--- a/drivers/net/sunvnet.c
+++ b/drivers/net/sunvnet.c
@@ -892,7 +892,7 @@ const char *remote_macaddr_prop = "remote-mac-address";
 static int __devinit vnet_port_probe(struct vio_dev *vdev,
                                      const struct vio_device_id *id)
 {
-        struct mdesc_node *endp;
+        struct mdesc_handle *hp;
         struct vnet_port *port;
         unsigned long flags;
         struct vnet *vp;
@@ -905,23 +905,21 @@ static int __devinit vnet_port_probe(struct vio_dev *vdev,
                 return -ENODEV;
         }
 
-        rmac = md_get_property(vdev->mp, remote_macaddr_prop, &len);
+        hp = mdesc_grab();
+
+        rmac = mdesc_get_property(hp, vdev->mp, remote_macaddr_prop, &len);
+        err = -ENODEV;
         if (!rmac) {
                 printk(KERN_ERR PFX "Port lacks %s property.\n",
                        remote_macaddr_prop);
-                return -ENODEV;
-        }
-
-        endp = vio_find_endpoint(vdev);
-        if (!endp) {
-                printk(KERN_ERR PFX "Port lacks channel-endpoint.\n");
-                return -ENODEV;
+                goto err_out_put_mdesc;
         }
 
         port = kzalloc(sizeof(*port), GFP_KERNEL);
+        err = -ENOMEM;
         if (!port) {
                 printk(KERN_ERR PFX "Cannot allocate vnet_port.\n");
-                return -ENOMEM;
+                goto err_out_put_mdesc;
         }
 
         for (i = 0; i < ETH_ALEN; i++)
@@ -929,7 +927,7 @@ static int __devinit vnet_port_probe(struct vio_dev *vdev,
 
         port->vp = vp;
 
-        err = vio_driver_init(&port->vio, vdev, VDEV_NETWORK, endp,
+        err = vio_driver_init(&port->vio, vdev, VDEV_NETWORK,
                               vnet_versions, ARRAY_SIZE(vnet_versions),
                               &vnet_vio_ops, vp->dev->name);
         if (err)
@@ -947,7 +945,7 @@ static int __devinit vnet_port_probe(struct vio_dev *vdev,
         INIT_LIST_HEAD(&port->list);
 
         switch_port = 0;
-        if (md_get_property(vdev->mp, "switch-port", NULL) != NULL)
+        if (mdesc_get_property(hp, vdev->mp, "switch-port", NULL) != NULL)
                 switch_port = 1;
 
         spin_lock_irqsave(&vp->lock, flags);
@@ -969,6 +967,8 @@ static int __devinit vnet_port_probe(struct vio_dev *vdev,
 
         vio_port_up(&port->vio);
 
+        mdesc_release(hp);
+
         return 0;
 
 err_out_free_ldc:
@@ -977,6 +977,8 @@ err_out_free_ldc:
 err_out_free_port:
         kfree(port);
 
+err_out_put_mdesc:
+        mdesc_release(hp);
         return err;
 }
 
@@ -1029,6 +1031,7 @@ static int __devinit vnet_probe(struct vio_dev *vdev,
                                 const struct vio_device_id *id)
 {
         static int vnet_version_printed;
+        struct mdesc_handle *hp;
         struct net_device *dev;
         struct vnet *vp;
         const u64 *mac;
@@ -1037,7 +1040,9 @@ static int __devinit vnet_probe(struct vio_dev *vdev,
         if (vnet_version_printed++ == 0)
                 printk(KERN_INFO "%s", version);
 
-        mac = md_get_property(vdev->mp, local_mac_prop, &len);
+        hp = mdesc_grab();
+
+        mac = mdesc_get_property(hp, vdev->mp, local_mac_prop, &len);
         if (!mac) {
                 printk(KERN_ERR PFX "vnet lacks %s property.\n",
                        local_mac_prop);
@@ -1093,12 +1098,15 @@ static int __devinit vnet_probe(struct vio_dev *vdev,
 
         dev_set_drvdata(&vdev->dev, vp);
 
+        mdesc_release(hp);
+
         return 0;
 
 err_out_free_dev:
         free_netdev(dev);
 
 err_out:
+        mdesc_release(hp);
         return err;
 }
 
diff --git a/include/asm-sparc64/mdesc.h b/include/asm-sparc64/mdesc.h
index c6383982b53d..bbb0c0bed486 100644
--- a/include/asm-sparc64/mdesc.h
+++ b/include/asm-sparc64/mdesc.h
@@ -4,36 +4,43 @@
 #include <linux/types.h>
 #include <asm/prom.h>
 
-struct mdesc_node;
-struct mdesc_arc {
-        const char              *name;
-        struct mdesc_node       *arc;
-};
-
-struct mdesc_node {
-        const char              *name;
-        u64                     node;
-        unsigned int            unique_id;
-        unsigned int            num_arcs;
-        unsigned int            irqs[2];
-        struct property         *properties;
-        struct mdesc_node       *hash_next;
-        struct mdesc_node       *allnodes_next;
-        struct mdesc_arc        arcs[0];
-};
-
-extern struct mdesc_node *md_find_node_by_name(struct mdesc_node *from,
-                                               const char *name);
-#define md_for_each_node_by_name(__mn, __name) \
-        for (__mn = md_find_node_by_name(NULL, __name); __mn; \
-             __mn = md_find_node_by_name(__mn, __name))
-
-extern struct property *md_find_property(const struct mdesc_node *mp,
-                                         const char *name,
-                                         int *lenp);
-extern const void *md_get_property(const struct mdesc_node *mp,
-                                   const char *name,
-                                   int *lenp);
+struct mdesc_handle;
+
+/* Machine description operations are to be surrounded by grab and
+ * release calls.  The mdesc_handle returned from the grab is
+ * the first argument to all of the operational calls that work
+ * on mdescs.
+ */
+extern struct mdesc_handle *mdesc_grab(void);
+extern void mdesc_release(struct mdesc_handle *);
+
+#define MDESC_NODE_NULL         (~(u64)0)
+
+extern u64 mdesc_node_by_name(struct mdesc_handle *handle,
+                              u64 from_node, const char *name);
+#define mdesc_for_each_node_by_name(__hdl, __node, __name) \
+        for (__node = mdesc_node_by_name(__hdl, MDESC_NODE_NULL, __name); \
+             (__node) != MDESC_NODE_NULL; \
+             __node = mdesc_node_by_name(__hdl, __node, __name))
+
+extern const void *mdesc_get_property(struct mdesc_handle *handle,
+                                      u64 node, const char *name, int *lenp);
+
+#define MDESC_ARC_TYPE_FWD      "fwd"
+#define MDESC_ARC_TYPE_BACK     "back"
+
+extern u64 mdesc_next_arc(struct mdesc_handle *handle, u64 from,
+                          const char *arc_type);
+#define mdesc_for_each_arc(__arc, __hdl, __node, __type) \
+        for (__arc = mdesc_next_arc(__hdl, __node, __type); \
+             (__arc) != MDESC_NODE_NULL; \
+             __arc = mdesc_next_arc(__hdl, __arc, __type))
+
+extern u64 mdesc_arc_target(struct mdesc_handle *hp, u64 arc);
+
+extern const char *mdesc_node_name(struct mdesc_handle *hp, u64 node);
+
+extern void mdesc_update(void);
 
 extern void sun4v_mdesc_init(void);
 
diff --git a/include/asm-sparc64/vio.h b/include/asm-sparc64/vio.h
index 47c3da76dcb8..a8a53e6fc250 100644
--- a/include/asm-sparc64/vio.h
+++ b/include/asm-sparc64/vio.h
@@ -265,13 +265,18 @@ static inline u32 vio_dring_avail(struct vio_dring_state *dr,
 }
 
 struct vio_dev {
-        struct mdesc_node       *mp;
+        u64                     mp;
         struct device_node      *dp;
 
         const char              *type;
         const char              *compat;
         int                     compat_len;
 
+        unsigned long           channel_id;
+
+        unsigned int            tx_irq;
+        unsigned int            rx_irq;
+
         struct device           dev;
 };
 
@@ -345,16 +350,10 @@ struct vio_driver_state {
 
         struct vio_dev          *vdev;
 
-        unsigned long           channel_id;
-        unsigned int            tx_irq;
-        unsigned int            rx_irq;
-
         struct timer_list       timer;
 
         struct vio_version      ver;
 
-        struct mdesc_node       *endpoint;
-
         struct vio_version      *ver_table;
         int                     ver_table_entries;
 
@@ -365,7 +364,8 @@ struct vio_driver_state {
 
 #define viodbg(TYPE, f, a...) \
 do {    if (vio->debug & VIO_DEBUG_##TYPE) \
-                printk(KERN_INFO "vio: ID[%lu] " f, vio->channel_id, ## a); \
+                printk(KERN_INFO "vio: ID[%lu] " f, \
+                       vio->vdev->channel_id, ## a); \
 } while (0)
 
 extern int vio_register_driver(struct vio_driver *drv);
@@ -392,11 +392,10 @@ extern int vio_ldc_alloc(struct vio_driver_state *vio,
                          struct ldc_channel_config *base_cfg, void *event_arg);
 extern void vio_ldc_free(struct vio_driver_state *vio);
 extern int vio_driver_init(struct vio_driver_state *vio, struct vio_dev *vdev,
-                           u8 dev_class, struct mdesc_node *channel_endpoint,
-                           struct vio_version *ver_table, int ver_table_size,
-                           struct vio_driver_ops *ops, char *name);
+                           u8 dev_class, struct vio_version *ver_table,
+                           int ver_table_size, struct vio_driver_ops *ops,
+                           char *name);
 
-extern struct mdesc_node *vio_find_endpoint(struct vio_dev *vdev);
 extern void vio_port_up(struct vio_driver_state *vio);
 
 #endif /* _SPARC64_VIO_H */