[ppc64] base support for dynamic update of OF device, tree from Nathan Lynch
---
arch/ppc64/kernel/prom.c | 411 ++++++++++++++++++++++++++++++++++++++++++++---
include/asm-ppc64/prom.h | 44 ++++-
2 files changed, 436 insertions(+), 19 deletions(-)
diff -puN arch/ppc64/kernel/prom.c~ppc64-device_tree_updates_2 arch/ppc64/kernel/prom.c
--- 25/arch/ppc64/kernel/prom.c~ppc64-device_tree_updates_2 2004-01-13 23:22:01.000000000 -0800
+++ 25-akpm/arch/ppc64/kernel/prom.c 2004-01-13 23:22:01.000000000 -0800
@@ -29,6 +29,7 @@
#include <linux/spinlock.h>
#include <linux/types.h>
#include <linux/pci.h>
+#include <linux/proc_fs.h>
#include <asm/prom.h>
#include <asm/rtas.h>
#include <asm/lmb.h>
@@ -44,6 +45,7 @@
#include <asm/bitops.h>
#include <asm/naca.h>
#include <asm/pci.h>
+#include <asm/pci_dma.h>
#include <asm/bootinfo.h>
#include <asm/ppcdebug.h>
#include "open_pic.h"
@@ -149,6 +151,10 @@ char *bootdevice = 0;
int boot_cpuid = 0;
struct device_node *allnodes = 0;
+/* use when traversing tree through the allnext, child, sibling,
+ * or parent members of struct device_node.
+ */
+static rwlock_t devtree_lock = RW_LOCK_UNLOCKED;
#define UNDEFINED_IRQ 0xffff
unsigned short real_irq_to_virt_map[NR_HW_IRQS];
@@ -168,6 +174,11 @@ static int prom_next_node(phandle *);
static struct bi_record * prom_bi_rec_verify(struct bi_record *);
static unsigned long prom_bi_rec_reserve(unsigned long);
static struct device_node *find_phandle(phandle);
+static void of_node_cleanup(struct device_node *);
+static struct device_node *derive_parent(const char *);
+static void add_node_proc_entries(struct device_node *);
+static void remove_node_proc_entries(struct device_node *);
+static int of_finish_dynamic_node(struct device_node *);
#ifdef DEBUG_PROM
void prom_dump_lmb(void);
@@ -2006,8 +2017,8 @@ find_path_device(const char *path)
/*******
*
* New implementation of the OF "find" APIs, return a refcounted
- * object, call of_node_put() when done. Currently, still lacks
- * locking as old implementation, this is being done for ppc64.
+ * object, call of_node_put() when done. The device tree and list
+ * are protected by a rw_lock.
*
* Note that property management will need some locking as well,
* this isn't dealt with yet.
@@ -2028,14 +2039,18 @@ find_path_device(const char *path)
struct device_node *of_find_node_by_name(struct device_node *from,
const char *name)
{
- struct device_node *np = from ? from->allnext : allnodes;
+ struct device_node *np;
+ read_lock(&devtree_lock);
+ np = from ? from->allnext : allnodes;
for (; np != 0; np = np->allnext)
- if (np->name != 0 && strcasecmp(np->name, name) == 0)
+ if (np->name != 0 && strcasecmp(np->name, name) == 0
+ && of_node_get(np))
break;
if (from)
of_node_put(from);
- return of_node_get(np);
+ read_unlock(&devtree_lock);
+ return np;
}
/**
@@ -2052,14 +2067,18 @@ struct device_node *of_find_node_by_name
struct device_node *of_find_node_by_type(struct device_node *from,
const char *type)
{
- struct device_node *np = from ? from->allnext : allnodes;
+ struct device_node *np;
+ read_lock(&devtree_lock);
+ np = from ? from->allnext : allnodes;
for (; np != 0; np = np->allnext)
- if (np->type != 0 && strcasecmp(np->type, type) == 0)
+ if (np->type != 0 && strcasecmp(np->type, type) == 0
+ && of_node_get(np))
break;
if (from)
of_node_put(from);
- return of_node_get(np);
+ read_unlock(&devtree_lock);
+ return np;
}
/**
@@ -2079,18 +2098,21 @@ struct device_node *of_find_node_by_type
struct device_node *of_find_compatible_node(struct device_node *from,
const char *type, const char *compatible)
{
- struct device_node *np = from ? from->allnext : allnodes;
+ struct device_node *np;
+ read_lock(&devtree_lock);
+ np = from ? from->allnext : allnodes;
for (; np != 0; np = np->allnext) {
if (type != NULL
&& !(np->type != 0 && strcasecmp(np->type, type) == 0))
continue;
- if (device_is_compatible(np, compatible))
+ if (device_is_compatible(np, compatible) && of_node_get(np))
break;
}
if (from)
of_node_put(from);
- return of_node_get(np);
+ read_unlock(&devtree_lock);
+ return np;
}
/**
@@ -2104,10 +2126,13 @@ struct device_node *of_find_node_by_path
{
struct device_node *np = allnodes;
+ read_lock(&devtree_lock);
for (; np != 0; np = np->allnext)
- if (np->full_name != 0 && strcasecmp(np->full_name, path) == 0)
+ if (np->full_name != 0 && strcasecmp(np->full_name, path) == 0
+ && of_node_get(np))
break;
- return of_node_get(np);
+ read_unlock(&devtree_lock);
+ return np;
}
/**
@@ -2120,11 +2145,17 @@ struct device_node *of_find_node_by_path
*/
struct device_node *of_find_all_nodes(struct device_node *prev)
{
- struct device_node *np = prev ? prev->allnext : allnodes;
+ struct device_node *np;
+ read_lock(&devtree_lock);
+ np = prev ? prev->allnext : allnodes;
+ for (; np != 0; np = np->allnext)
+ if (of_node_get(np))
+ break;
if (prev)
of_node_put(prev);
- return of_node_get(np);
+ read_unlock(&devtree_lock);
+ return np;
}
/**
@@ -2136,7 +2167,15 @@ struct device_node *of_find_all_nodes(st
*/
struct device_node *of_get_parent(const struct device_node *node)
{
- return node ? of_node_get(node->parent) : NULL;
+ struct device_node *np;
+
+ if (!node)
+ return NULL;
+
+ read_lock(&devtree_lock);
+ np = of_node_get(node->parent);
+ read_unlock(&devtree_lock);
+ return np;
}
/**
@@ -2150,13 +2189,16 @@ struct device_node *of_get_parent(const
struct device_node *of_get_next_child(const struct device_node *node,
struct device_node *prev)
{
- struct device_node *next = prev ? prev->sibling : node->child;
+ struct device_node *next;
+ read_lock(&devtree_lock);
+ next = prev ? prev->sibling : node->child;
for (; next != 0; next = next->sibling)
if (of_node_get(next))
break;
if (prev)
of_node_put(prev);
+ read_unlock(&devtree_lock);
return next;
}
@@ -2169,7 +2211,11 @@ struct device_node *of_get_next_child(co
*/
struct device_node *of_node_get(struct device_node *node)
{
- return node;
+ if (node && !OF_IS_STALE(node)) {
+ atomic_inc(&node->_users);
+ return node;
+ }
+ return NULL;
}
/**
@@ -2180,6 +2226,335 @@ struct device_node *of_node_get(struct d
*/
void of_node_put(struct device_node *node)
{
+ if (!node)
+ return;
+
+ WARN_ON(0 == atomic_read(&node->_users));
+
+ if (OF_IS_STALE(node)) {
+ if (atomic_dec_and_test(&node->_users)) {
+ of_node_cleanup(node);
+ return;
+ }
+ }
+ else
+ atomic_dec(&node->_users);
+}
+
+/**
+ * of_node_cleanup - release a dynamically allocated node
+ * @arg: Node to be released
+ */
+static void of_node_cleanup(struct device_node *node)
+{
+ struct property *prop = node->properties;
+
+ if (!OF_IS_DYNAMIC(node))
+ return;
+ while (prop) {
+ struct property *next = prop->next;
+ kfree(prop->name);
+ kfree(prop->value);
+ kfree(prop);
+ prop = next;
+ }
+ kfree(node->intrs);
+ kfree(node->addrs);
+ kfree(node->full_name);
+ kfree(node);
+}
+
+/**
+ * derive_parent - basically like dirname(1)
+ * @path: the full_name of a node to be added to the tree
+ *
+ * Returns the node which should be the parent of the node
+ * described by path. E.g., for path = "/foo/bar", returns
+ * the node with full_name = "/foo".
+ */
+static struct device_node *derive_parent(const char *path)
+{
+ struct device_node *parent = NULL;
+ char *parent_path = "/";
+ size_t parent_path_len = strrchr(path, '/') - path + 1;
+
+ /* reject if path is "/" */
+ if (!strcmp(path, "/"))
+ return NULL;
+
+ if (strrchr(path, '/') != path) {
+ parent_path = kmalloc(parent_path_len, GFP_KERNEL);
+ if (!parent_path)
+ return NULL;
+ strlcpy(parent_path, path, parent_path_len);
+ }
+ parent = of_find_node_by_path(parent_path);
+ if (strcmp(parent_path, "/"))
+ kfree(parent_path);
+ return parent;
+}
+
+/*
+ * Routines for "runtime" addition and removal of device tree nodes.
+ */
+
+/*
+ * Given a path and a property list, construct an OF device node, add
+ * it to the device tree and global list, and place it in
+ * /proc/device-tree. This function may sleep.
+ */
+int of_add_node(const char *path, struct property *proplist)
+{
+ struct device_node *np;
+ int err = 0;
+
+ np = kmalloc(sizeof(struct device_node), GFP_KERNEL);
+ if (!np)
+ return -ENOMEM;
+
+ memset(np, 0, sizeof(*np));
+
+ np->full_name = kmalloc(strlen(path) + 1, GFP_KERNEL);
+ if (!np->full_name) {
+ kfree(np);
+ return -ENOMEM;
+ }
+ strcpy(np->full_name, path);
+
+ np->properties = proplist;
+ OF_MARK_DYNAMIC(np);
+ of_node_get(np);
+ np->parent = derive_parent(path);
+ if (!np->parent) {
+ kfree(np);
+ return -EINVAL; /* could also be ENOMEM, though */
+ }
+
+ if (0 != (err = of_finish_dynamic_node(np))) {
+ kfree(np);
+ return err;
+ }
+
+ write_lock(&devtree_lock);
+ np->sibling = np->parent->child;
+ np->allnext = allnodes;
+ np->parent->child = np;
+ allnodes = np;
+ write_unlock(&devtree_lock);
+
+ add_node_proc_entries(np);
+
+ of_node_put(np->parent);
+ of_node_put(np);
+ return 0;
+}
+
+/*
+ * Remove an OF device node from the system.
+ */
+int of_remove_node(struct device_node *np)
+{
+ struct device_node *parent, *child;
+
+ parent = of_get_parent(np);
+ child = of_get_next_child(np, NULL);
+ if (child && !child->child && !child->sibling) {
+ /* For now, we will allow removal of a
+ * node with one and only one child, so
+ * that we can support removing a slot with
+ * an IOA in it. More general support for
+ * subtree removal to be implemented later, if
+ * necessary.
+ */
+ of_remove_node(child);
+ }
+ else if (child) {
+ of_node_put(child);
+ of_node_put(parent);
+ return -EINVAL;
+ }
+ of_node_put(child);
+
+ write_lock(&devtree_lock);
+ OF_MARK_STALE(np);
+ remove_node_proc_entries(np);
+ if (allnodes == np)
+ allnodes = np->allnext;
+ else {
+ struct device_node *prev;
+ for (prev = allnodes;
+ prev->allnext != np;
+ prev = prev->allnext)
+ ;
+ prev->allnext = np->allnext;
+ }
+
+ if (np->parent->child == np)
+ np->parent->child = np->sibling;
+ else {
+ struct device_node *prevsib;
+ for (prevsib = np->parent->child;
+ prevsib->sibling != np;
+ prevsib = prevsib->sibling)
+ ;
+ prevsib->sibling = np->sibling;
+ }
+ write_unlock(&devtree_lock);
+ of_node_put(parent);
+ return 0;
+}
+
+/*
+ * Add a node to /proc/device-tree.
+ */
+static void add_node_proc_entries(struct device_node *np)
+{
+ struct proc_dir_entry *ent;
+
+ ent = proc_mkdir(strrchr(np->full_name, '/') + 1, np->parent->pde);
+ if (ent)
+ proc_device_tree_add_node(np, ent);
+}
+
+static void remove_node_proc_entries(struct device_node *np)
+{
+ struct property *pp = np->properties;
+ struct device_node *parent = np->parent;
+
+ while (pp) {
+ remove_proc_entry(pp->name, np->pde);
+ pp = pp->next;
+ }
+
+ /* Assuming that symlinks have the same parent directory as
+ * np->pde.
+ */
+ if (np->name_link)
+ remove_proc_entry(np->name_link->name, parent->pde);
+ if (np->addr_link)
+ remove_proc_entry(np->addr_link->name, parent->pde);
+ if (np->pde)
+ remove_proc_entry(np->pde->name, parent->pde);
+}
+
+/*
+ * Fix up the uninitialized fields in a new device node:
+ * name, type, n_addrs, addrs, n_intrs, intrs, and pci-specific fields
+ *
+ * A lot of boot-time code is duplicated here, because functions such
+ * as finish_node_interrupts, interpret_pci_props, etc. cannot use the
+ * slab allocator.
+ *
+ * This should probably be split up into smaller chunks.
+ */
+
+static int of_finish_dynamic_node(struct device_node *node)
+{
+ struct device_node *parent = of_get_parent(node);
+ u32 *regs;
+ unsigned int *ints;
+ int intlen, intrcells;
+ int i, j, n, err = 0;
+ unsigned int *irq;
+ struct device_node *ic;
+
+ node->name = get_property(node, "name", 0);
+ node->type = get_property(node, "device_type", 0);
+
+ if (!parent) {
+ err = -ENODEV;
+ goto out;
+ }
+
+ /* do the work of interpret_pci_props */
+ if (parent->type && !strcmp(parent->type, "pci")) {
+ struct address_range *adr;
+ struct pci_reg_property *pci_addrs;
+ int i, l;
+
+ pci_addrs = (struct pci_reg_property *)
+ get_property(node, "assigned-addresses", &l);
+ if (pci_addrs != 0 && l >= sizeof(struct pci_reg_property)) {
+ i = 0;
+ adr = kmalloc(sizeof(struct address_range) *
+ (l / sizeof(struct pci_reg_property)),
+ GFP_KERNEL);
+ if (!adr) {
+ err = -ENOMEM;
+ goto out;
+ }
+ while ((l -= sizeof(struct pci_reg_property)) >= 0) {
+ adr[i].space = pci_addrs[i].addr.a_hi;
+ adr[i].address = pci_addrs[i].addr.a_lo;
+ adr[i].size = pci_addrs[i].size_lo;
+ ++i;
+ }
+ node->addrs = adr;
+ node->n_addrs = i;
+ }
+ }
+
+ /* now do the work of finish_node_interrupts */
+
+ ints = (unsigned int *) get_property(node, "interrupts", &intlen);
+ if (!ints)
+ goto out;
+
+ intrcells = prom_n_intr_cells(node);
+ intlen /= intrcells * sizeof(unsigned int);
+ node->n_intrs = intlen;
+ node->intrs = kmalloc(sizeof(struct interrupt_info) * intlen,
+ GFP_KERNEL);
+ if (!node->intrs) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ for (i = 0; i < intlen; ++i) {
+ node->intrs[i].line = 0;
+ node->intrs[i].sense = 1;
+ n = map_interrupt(&irq, &ic, node, ints, intrcells);
+ if (n <= 0)
+ continue;
+ node->intrs[i].line = openpic_to_irq(virt_irq_create_mapping(irq[0]));
+ if (n > 1)
+ node->intrs[i].sense = irq[1];
+ if (n > 2) {
+ printk(KERN_DEBUG "hmmm, got %d intr cells for %s:", n,
+ node->full_name);
+ for (j = 0; j < n; ++j)
+ printk(" %d", irq[j]);
+ printk("\n");
+ }
+ ints += intrcells;
+ }
+
+ /* now do the rough equivalent of update_dn_pci_info, this
+ * probably is not correct for phb's, but should work for
+ * IOAs and slots.
+ */
+
+ node->phb = parent->phb;
+
+ regs = (u32 *)get_property(node, "reg", 0);
+ if (regs) {
+ node->busno = (regs[0] >> 16) & 0xff;
+ node->devfn = (regs[0] >> 8) & 0xff;
+ }
+
+ /* fixing up tce_table */
+
+ if(strcmp(node->name, "pci") == 0 &&
+ get_property(node, "ibm,dma-window", NULL)) {
+ node->bussubno = node->busno;
+ create_pci_bus_tce_table((unsigned long)node);
+ }
+ else
+ node->tce_table = parent->tce_table;
+
+out:
+ of_node_put(parent);
+ return err;
}
/*
diff -puN include/asm-ppc64/prom.h~ppc64-device_tree_updates_2 include/asm-ppc64/prom.h
--- 25/include/asm-ppc64/prom.h~ppc64-device_tree_updates_2 2004-01-13 23:22:01.000000000 -0800
+++ 25-akpm/include/asm-ppc64/prom.h 2004-01-13 23:22:01.000000000 -0800
@@ -14,6 +14,8 @@
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
+#include <linux/proc_fs.h>
+#include <asm/atomic.h>
#define PTRRELOC(x) ((typeof(x))((unsigned long)(x) - offset))
#define PTRUNRELOC(x) ((typeof(x))((unsigned long)(x) + offset))
@@ -144,7 +146,43 @@ struct device_node {
struct device_node *sibling;
struct device_node *next; /* next device of same type */
struct device_node *allnext; /* next in list of all nodes */
-};
+ struct proc_dir_entry *pde; /* this node's proc directory */
+ struct proc_dir_entry *name_link; /* name symlink */
+ struct proc_dir_entry *addr_link; /* addr symlink */
+ atomic_t _users; /* reference count */
+ unsigned long _flags;
+};
+
+/* flag descriptions */
+#define OF_STALE 0 /* node is slated for deletion */
+#define OF_DYNAMIC 1 /* node and properties were allocated via kmalloc */
+
+#define OF_IS_STALE(x) test_bit(OF_STALE, &x->_flags)
+#define OF_MARK_STALE(x) set_bit(OF_STALE, &x->_flags)
+#define OF_IS_DYNAMIC(x) test_bit(OF_DYNAMIC, &x->_flags)
+#define OF_MARK_DYNAMIC(x) set_bit(OF_DYNAMIC, &x->_flags)
+
+/*
+ * Until 32-bit ppc can add proc_dir_entries to its device_node
+ * definition, we cannot refer to pde, name_link, and addr_link
+ * in arch-independent code.
+ */
+#define HAVE_ARCH_DEVTREE_FIXUPS
+
+static inline void set_node_proc_entry(struct device_node *dn, struct proc_dir_entry *de)
+{
+ dn->pde = de;
+}
+
+static void inline set_node_name_link(struct device_node *dn, struct proc_dir_entry *de)
+{
+ dn->name_link = de;
+}
+
+static void inline set_node_addr_link(struct device_node *dn, struct proc_dir_entry *de)
+{
+ dn->addr_link = de;
+}
typedef u32 prom_arg_t;
@@ -196,6 +234,10 @@ extern struct device_node *of_get_next_c
extern struct device_node *of_node_get(struct device_node *node);
extern void of_node_put(struct device_node *node);
+/* For updating the device tree at runtime */
+extern int of_add_node(const char *path, struct property *proplist);
+extern int of_remove_node(struct device_node *np);
+
/* Other Prototypes */
extern void abort(void);
extern unsigned long prom_init(unsigned long, unsigned long, unsigned long,
_