/* mdesc.c: Sun4V machine description handling.
*
* Copyright (C) 2007, 2008 David S. Miller <davem@davemloft.net>
*/
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/memblock.h>
#include <linux/log2.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/miscdevice.h>
#include <linux/bootmem.h>
#include <linux/export.h>
#include <asm/cpudata.h>
#include <asm/hypervisor.h>
#include <asm/mdesc.h>
#include <asm/prom.h>
#include <asm/uaccess.h>
#include <asm/oplib.h>
#include <asm/smp.h>
/* Unlike the OBP device tree, the machine description is a full-on
* DAG. An arbitrary number of ARCs are possible from one
* node to other nodes and thus we can't use the OBP device_node
* data structure to represent these nodes inside of the kernel.
*
* Actually, it isn't even a DAG, because there are back pointers
* which create cycles in the graph.
*
* mdesc_hdr and mdesc_elem describe the layout of the data structure
* we get from the Hypervisor.
*/
struct mdesc_hdr {
u32 version; /* Transport version */
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;
#define MD_LIST_END 0x00
#define MD_NODE 0x4e
#define MD_NODE_END 0x45
#define MD_NOOP 0x20
#define MD_PROP_ARC 0x61
#define MD_PROP_VAL 0x76
#define MD_PROP_STR 0x73
#define MD_PROP_DATA 0x64
u8 name_len;
u16 resv;
u32 name_offset;
union {
struct {
u32 data_len;
u32 data_offset;
} data;
u64 val;
} d;
};
struct mdesc_mem_ops {
struct mdesc_handle *(*alloc)(unsigned int mdesc_size);
void (*free)(struct mdesc_handle *handle);
};
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 void mdesc_handle_init(struct mdesc_handle *hp,
unsigned int handle_size,
void *base)
{
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 struct mdesc_handle * __init mdesc_memblock_alloc(unsigned int mdesc_size)
{
unsigned int handle_size, alloc_size;
struct mdesc_handle *hp;
unsigned long paddr;
handle_size = (sizeof(struct mdesc_handle) -
sizeof(struct mdesc_hdr) +
mdesc_size);
alloc_size = PAGE_ALIGN(handle_size);
paddr = memblock_alloc(alloc_size, PAGE_SIZE);
hp = NULL;
if (paddr) {
hp = __va(paddr);
mdesc_handle_init(hp, handle_size, hp);
}
return hp;
}
static void __init mdesc_memblock_free(struct mdesc_handle *hp)
{
unsigned int alloc_size;
unsigned long start;
BUG_ON(atomic_read(&hp->refcnt) != 0);
BUG_ON(!list_empty(&hp->list));
alloc_size = PAGE_ALIGN(hp->handle_size);
start = __pa(hp);
free_bootmem_late(start, alloc_size);
}
static struct mdesc_mem_ops memblock_mdesc_ops = {
.alloc = mdesc_memblock_alloc,
.free = mdesc_memblock_free,
};
static struct mdesc_handle *mdesc_kmalloc(unsigned int mdesc_size)
{
unsigned int handle_size;
void *base;
handle_size = (sizeof(struct mdesc_handle) -
sizeof(struct mdesc_hdr) +
mdesc_size);
base = kmalloc(handle_size + 15, GFP_KERNEL | __GFP_NOFAIL);
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 NULL;
}
static void mdesc_kfree(struct mdesc_handle *hp)
{
BUG_ON(atomic_read(&hp->refcnt) != 0);
BUG_ON(!list_empty(&hp->list));
kfree(hp->self_base);
}
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_handle *hp = mops->alloc(mdesc_size);
if (hp)
hp->mops = mops;
return hp;
}
static void mdesc_free(struct mdesc_handle *hp)
{
hp->mops->free(hp);
}
static struct mdesc_handle *cur_mdesc;
static LIST_HEAD(mdesc_zombie_list);
static DEFINE_SPINLOCK(mdesc_lock);
struct mdesc_handle *mdesc_grab(void)
{
struct mdesc_handle *hp;
unsigned long flags;
spin_lock_irqsave(&mdesc_lock, flags);
hp = cur_mdesc;
if (hp)
atomic_inc(&hp->refcnt);
spin_unlock_irqrestore(&mdesc_lock, flags);
return hp;
}
EXPORT_SYMBOL(mdesc_grab);
void mdesc_release(struct mdesc_handle *hp)
{
unsigned long flags;
spin_lock_irqsave(&mdesc_lock, flags);
if (atomic_dec_and_test(&hp->refcnt)) {
list_del_init(&hp->list);
hp->mops->free(hp);
}
spin_unlock_irqrestore(&mdesc_lock, flags);
}
EXPORT_SYMBOL(mdesc_release);
static DEFINE_MUTEX(mdesc_mutex);
static struct mdesc_notifier_client *client_list;
void mdesc_register_notifier(struct mdesc_notifier_client *client)
{
u64 node;
mutex_lock(&mdesc_mutex);
client->next = client_list;
client_list = client;
mdesc_for_each_node_by_name(cur_mdesc, node, client->node_name)
client->add(cur_mdesc, node);
mutex_unlock(&mdesc_mutex);
}
static const u64 *parent_cfg_handle(struct mdesc_handle *hp, u64 node)
{
const u64 *id;
u64 a;
id = NULL;
mdesc_for_each_arc(a, hp, node, MDESC_ARC_TYPE_BACK) {
u64 target;
target = mdesc_arc_target(hp, a);
id = mdesc_get_property(hp, target,
"cfg-handle", NULL);
if (id)
break;
}
return id;
}
/* Run 'func' on nodes which are in A but not in B. */
static void invoke_on_missing(const char *name,
struct mdesc_handle *a,
struct mdesc_handle *b,
void (*func)(struct mdesc_handle *, u64))
{
u64 node;
mdesc_for_each_node_by_name(a, node, name) {
int found = 0, is_vdc_port = 0;
const char *name_prop;
const u64 *id;
u64 fnode;
name_prop = mdesc_get_property(a, node, "name", NULL);
if (name_prop && !strcmp(name_prop, "vdc-port")) {
is_vdc_port = 1;
id = parent_cfg_handle(a, node);
} else
id = mdesc_get_property(a, node, "id", NULL);
if (!id) {
printk(KERN_ERR "MD: Cannot find ID for %s node.\n",
(name_prop ? name_prop : name));
continue;
}
mdesc_for_each_node_by_name(b, fnode, name) {
const u64 *fid;
if (is_vdc_port) {
name_prop = mdesc_get_property(b, fnode,
"name", NULL);
if (!name_prop ||
strcmp(name_prop, "vdc-port"))
continue;
fid = parent_cfg_handle(b, fnode);
if (!fid) {
printk(KERN_ERR "MD: Cannot find ID "
"for vdc-port node.\n");
continue;
}
} else
fid = mdesc_get_property(b, fnode,
"id", NULL);
if (*id == *fid) {
found = 1;
break;
}
}
if (!found)
func(a, node);
}
}
static void notify_one(struct mdesc_notifier_client *p,
struct mdesc_handle *old_hp,
struct mdesc_handle *new_hp)
{
invoke_on_missing(p->node_name, old_hp, new_hp, p->remove);
invoke_on_missing(p->node_name, new_hp, old_hp, p->add);
}
static void mdesc_notify_clients(struct mdesc_handle *old_hp,
struct mdesc_handle *new_hp)
{
struct mdesc_notifier_client *p = client_list;
while (p) {
notify_one(p, old_hp, new_hp);
p = p->next;
}
}
void mdesc_update(void)
{
unsigned long len, real_len, status;
struct mdesc_handle *hp, *orig_hp;
unsigned long flags;
mutex_lock(&mdesc_mutex);
(void) sun4v_mach_desc(0UL, 0UL, &len);
hp = mdesc_alloc(len, &kmalloc_mdesc_memops);
if (!hp) {
printk(KERN_ERR "MD: mdesc alloc fails\n");
goto out;
}
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);
goto out;
}
spin_lock_irqsave(&mdesc_lock, flags);
orig_hp = cur_mdesc;
cur_mdesc = hp;
spin_unlock_irqrestore(&mdesc_lock, flags);
mdesc_notify_clients(orig_hp, hp);
spin_lock_irqsave(&mdesc_lock, flags);
if (atomic_dec_and_test
