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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH V4 05/32] xen/arm: Create a hierarchical device tree
Add function to parse the device tree and create a hierarchical tree.
This code is based on drivers/of/base.c in linux source.
Signed-off-by: Julien Grall <julien.grall@xxxxxxxxxx>
Changes in v4:
- Replace dt_printk by a macro to avoid double buffering
Changes in v3:
- Remove dt_switch_to_printk
- Use system_state to choose between early_printk and printk
- Remove DT_USE_BY_XEN, instead use DOMID_XEN
Changes in v2:
- s/dom0$/device/ in comment "By default dom0 owns the dom0"
- Use DOMID_XEN instead of DOMID_INVALID for DT_USED_BY_XEN
---
xen/arch/arm/setup.c | 1 +
xen/common/device_tree.c | 455 ++++++++++++++++++++++++++++++++++++++++-
xen/include/xen/device_tree.h | 89 ++++++++
3 files changed, 540 insertions(+), 5 deletions(-)
diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
index a667db4..81bc956 100644
--- a/xen/arch/arm/setup.c
+++ b/xen/arch/arm/setup.c
@@ -430,6 +430,7 @@ void __init start_xen(unsigned long boot_phys_offset,
setup_mm(fdt_paddr, fdt_size);
vm_init();
+ dt_unflatten_host_device_tree();
#ifdef EARLY_UART_ADDRESS
/* TODO Need to get device tree or command line for UART address */
diff --git a/xen/common/device_tree.c b/xen/common/device_tree.c
index 7997f41..215feb1 100644
--- a/xen/common/device_tree.c
+++ b/xen/common/device_tree.c
@@ -2,6 +2,8 @@
* Device Tree
*
* Copyright (C) 2012 Citrix Systems, Inc.
+ * Copyright 2009 Benjamin Herrenschmidt, IBM Corp
+ * benh@xxxxxxxxxxxxxxxxxxx
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
@@ -19,14 +21,56 @@
#include <xen/stdarg.h>
#include <xen/string.h>
#include <xen/cpumask.h>
+#include <xen/ctype.h>
+#include <xen/lib.h>
#include <asm/early_printk.h>
struct dt_early_info __initdata early_info;
void *device_tree_flattened;
+/* Host device tree */
+struct dt_device_node *dt_host;
+
+/**
+ * struct dt_alias_prop - Alias property in 'aliases' node
+ * @link: List node to link the structure in aliases_lookup list
+ * @alias: Alias property name
+ * @np: Pointer to device_node that the alias stands for
+ * @id: Index value from end of alias name
+ * @stem: Alias string without the index
+ *
+ * The structure represents one alias property of 'aliases' node as
+ * an entry in aliases_lookup list.
+ */
+struct dt_alias_prop {
+ struct list_head link;
+ const char *alias;
+ struct dt_device_node *np;
+ int id;
+ char stem[0];
+};
+
+static LIST_HEAD(aliases_lookup);
/* Some device tree functions may be called both before and after the
console is initialized. */
-static void (*dt_printk)(const char *fmt, ...) = early_printk;
+#define dt_printk(fmt, ...) \
+ do \
+ { \
+ if ( system_state == SYS_STATE_early_boot ) \
+ early_printk(fmt, ## __VA_ARGS__); \
+ else \
+ printk(fmt, ## __VA_ARGS__); \
+ } while (0)
+
+#define ALIGN(x, a) ((x + (a) - 1) & ~((a) - 1));
+
+// #define DEBUG_DT
+
+#ifdef DEBUG_DT
+# define dt_dprintk(fmt, args...) dt_printk(XENLOG_DEBUG fmt, ##args)
+#else
+# define dt_dprintk(fmt, args...) do {} while ( 0 )
+#endif
bool_t device_tree_node_matches(const void *fdt, int node, const char *match)
{
@@ -263,7 +307,7 @@ static int dump_node(const void *fdt, int node, const char
*name, int depth,
if ( name[0] == '\0' )
name = "/";
- printk("%s%s:\n", prefix, name);
+ dt_printk("%s%s:\n", prefix, name);
for ( prop = fdt_first_property_offset(fdt, node);
prop >= 0;
@@ -273,7 +317,7 @@ static int dump_node(const void *fdt, int node, const char
*name, int depth,
p = fdt_get_property_by_offset(fdt, prop, NULL);
- printk("%s %s\n", prefix, fdt_string(fdt, fdt32_to_cpu(p->nameoff)));
+ dt_printk("%s %s\n", prefix, fdt_string(fdt,
fdt32_to_cpu(p->nameoff)));
}
return 0;
@@ -488,11 +532,412 @@ size_t __init device_tree_early_init(const void *fdt)
device_tree_for_each_node((void *)fdt, early_scan_node, NULL);
early_print_info();
- dt_printk = printk;
-
return fdt_totalsize(fdt);
}
+static void __init *unflatten_dt_alloc(unsigned long *mem, unsigned long size,
+ unsigned long align)
+{
+ void *res;
+
+ *mem = ALIGN(*mem, align);
+ res = (void *)*mem;
+ *mem += size;
+
+ return res;
+}
+
+/* Find a property with a given name for a given node and return it. */
+static const struct dt_property *
+dt_find_property(const struct dt_device_node *np,
+ const char *name,
+ u32 *lenp)
+{
+ const struct dt_property *pp;
+
+ if ( !np )
+ return NULL;
+
+ for ( pp = np->properties; pp; pp = pp->next )
+ {
+ if ( strcmp(pp->name, name) == 0 )
+ {
+ if ( lenp )
+ *lenp = pp->length;
+ break;
+ }
+ }
+
+ return pp;
+}
+
+const void *dt_get_property(const struct dt_device_node *np,
+ const char *name, u32 *lenp)
+{
+ const struct dt_property *pp = dt_find_property(np, name, lenp);
+
+ return pp ? pp->value : NULL;
+}
+
+struct dt_device_node *dt_find_node_by_path(const char *path)
+{
+ struct dt_device_node *np;
+
+ for_each_device_node(dt_host, np)
+ if ( np->full_name && (dt_node_cmp(np->full_name, path) == 0) )
+ break;
+
+ return np;
+}
+
+/**
+ * unflatten_dt_node - Alloc and populate a device_node from the flat tree
+ * @fdt: The parent device tree blob
+ * @mem: Memory chunk to use for allocating device nodes and properties
+ * @p: pointer to node in flat tree
+ * @dad: Parent struct device_node
+ * @allnextpp: pointer to ->allnext from last allocated device_node
+ * @fpsize: Size of the node path up at the current depth.
+ */
+static unsigned long __init unflatten_dt_node(const void *fdt,
+ unsigned long mem,
+ unsigned long *p,
+ struct dt_device_node *dad,
+ struct dt_device_node
***allnextpp,
+ unsigned long fpsize)
+{
+ struct dt_device_node *np;
+ struct dt_property *pp, **prev_pp = NULL;
+ char *pathp;
+ u32 tag;
+ unsigned int l, allocl;
+ int has_name = 0;
+ int new_format = 0;
+
+ tag = be32_to_cpup((__be32 *)(*p));
+ if ( tag != FDT_BEGIN_NODE )
+ {
+ dt_printk(XENLOG_WARNING "Weird tag at start of node: %x\n", tag);
+ return mem;
+ }
+ *p += 4;
+ pathp = (char *)*p;
+ l = allocl = strlen(pathp) + 1;
+ *p = ALIGN(*p + l, 4);
+
+ /* version 0x10 has a more compact unit name here instead of the full
+ * path. we accumulate the full path size using "fpsize", we'll rebuild
+ * it later. We detect this because the first character of the name is
+ * not '/'.
+ */
+ if ( (*pathp) != '/' )
+ {
+ new_format = 1;
+ if ( fpsize == 0 )
+ {
+ /* root node: special case. fpsize accounts for path
+ * plus terminating zero. root node only has '/', so
+ * fpsize should be 2, but we want to avoid the first
+ * level nodes to have two '/' so we use fpsize 1 here
+ */
+ fpsize = 1;
+ allocl = 2;
+ }
+ else
+ {
+ /* account for '/' and path size minus terminal 0
+ * already in 'l'
+ */
+ fpsize += l;
+ allocl = fpsize;
+ }
+ }
+
+ np = unflatten_dt_alloc(&mem, sizeof(struct dt_device_node) + allocl,
+ __alignof__(struct dt_device_node));
+ if ( allnextpp )
+ {
+ memset(np, 0, sizeof(*np));
+ np->full_name = ((char *)np) + sizeof(struct dt_device_node);
+ /* By default dom0 owns the device */
+ np->used_by = 0;
+ if ( new_format )
+ {
+ char *fn = np->full_name;
+ /* rebuild full path for new format */
+ if ( dad && dad->parent )
+ {
+ strlcpy(fn, dad->full_name, allocl);
+#ifdef DEBUG_DT
+ if ( (strlen(fn) + l + 1) != allocl )
+ {
+ dt_dprintk("%s: p: %d, l: %d, a: %d\n",
+ pathp, (int)strlen(fn),
+ l, allocl);
+ }
+#endif
+ fn += strlen(fn);
+ }
+ *(fn++) = '/';
+ memcpy(fn, pathp, l);
+ }
+ else
+ memcpy(np->full_name, pathp, l);
+ prev_pp = &np->properties;
+ **allnextpp = np;
+ *allnextpp = &np->allnext;
+ if ( dad != NULL )
+ {
+ np->parent = dad;
+ /* we temporarily use the next field as `last_child'*/
+ if ( dad->next == NULL )
+ dad->child = np;
+ else
+ dad->next->sibling = np;
+ dad->next = np;
+ }
+ }
+ /* process properties */
+ while ( 1 )
+ {
+ u32 sz, noff;
+ const char *pname;
+
+ tag = be32_to_cpup((__be32 *)(*p));
+ if ( tag == FDT_NOP )
+ {
+ *p += 4;
+ continue;
+ }
+ if ( tag != FDT_PROP )
+ break;
+ *p += 4;
+ sz = be32_to_cpup((__be32 *)(*p));
+ noff = be32_to_cpup((__be32 *)((*p) + 4));
+ *p += 8;
+ if ( fdt_version(fdt) < 0x10 )
+ *p = ALIGN(*p, sz >= 8 ? 8 : 4);
+
+ pname = fdt_string(fdt, noff);
+ if ( pname == NULL )
+ {
+ dt_dprintk("Can't find property name in list!\n");
+ break;
+ }
+ if ( strcmp(pname, "name") == 0 )
+ has_name = 1;
+ l = strlen(pname) + 1;
+ pp = unflatten_dt_alloc(&mem, sizeof(struct dt_property),
+ __alignof__(struct dt_property));
+ if ( allnextpp )
+ {
+ /* We accept flattened tree phandles either in
+ * ePAPR-style "phandle" properties, or the
+ * legacy "linux,phandle" properties. If both
+ * appear and have different values, things
+ * will get weird. Don't do that. */
+ if ( (strcmp(pname, "phandle") == 0) ||
+ (strcmp(pname, "linux,phandle") == 0) )
+ {
+ if ( np->phandle == 0 )
+ np->phandle = be32_to_cpup((__be32*)*p);
+ }
+ /* And we process the "ibm,phandle" property
+ * used in pSeries dynamic device tree
+ * stuff */
+ if ( strcmp(pname, "ibm,phandle") == 0 )
+ np->phandle = be32_to_cpup((__be32 *)*p);
+ pp->name = pname;
+ pp->length = sz;
+ pp->value = (void *)*p;
+ *prev_pp = pp;
+ prev_pp = &pp->next;
+ }
+ *p = ALIGN((*p) + sz, 4);
+ }
+ /* with version 0x10 we may not have the name property, recreate
+ * it here from the unit name if absent
+ */
+ if ( !has_name )
+ {
+ char *p1 = pathp, *ps = pathp, *pa = NULL;
+ int sz;
+
+ while ( *p1 )
+ {
+ if ( (*p1) == '@' )
+ pa = p1;
+ if ( (*p1) == '/' )
+ ps = p1 + 1;
+ p1++;
+ }
+ if ( pa < ps )
+ pa = p1;
+ sz = (pa - ps) + 1;
+ pp = unflatten_dt_alloc(&mem, sizeof(struct dt_property) + sz,
+ __alignof__(struct dt_property));
+ if ( allnextpp )
+ {
+ pp->name = "name";
+ pp->length = sz;
+ pp->value = pp + 1;
+ *prev_pp = pp;
+ prev_pp = &pp->next;
+ memcpy(pp->value, ps, sz - 1);
+ ((char *)pp->value)[sz - 1] = 0;
+ dt_dprintk("fixed up name for %s -> %s\n", pathp,
+ (char *)pp->value);
+ }
+ }
+ if ( allnextpp )
+ {
+ *prev_pp = NULL;
+ np->name = dt_get_property(np, "name", NULL);
+ np->type = dt_get_property(np, "device_type", NULL);
+
+ if ( !np->name )
+ np->name = "<NULL>";
+ if ( !np->type )
+ np->type = "<NULL>";
+ }
+ while ( tag == FDT_BEGIN_NODE || tag == FDT_NOP )
+ {
+ if ( tag == FDT_NOP )
+ *p += 4;
+ else
+ mem = unflatten_dt_node(fdt, mem, p, np, allnextpp, fpsize);
+ tag = be32_to_cpup((__be32 *)(*p));
+ }
+ if ( tag != FDT_END_NODE )
+ {
+ dt_printk(XENLOG_WARNING "Weird tag at end of node: %x\n", tag);
+ return mem;
+ }
+
+ *p += 4;
+ return mem;
+}
+
+/**
+ * __unflatten_device_tree - create tree of device_nodes from flat blob
+ *
+ * unflattens a device-tree, creating the
+ * tree of struct device_node. It also fills the "name" and "type"
+ * pointers of the nodes so the normal device-tree walking functions
+ * can be used.
+ * @fdt: The fdt to expand
+ * @mynodes: The device_node tree created by the call
+ */
+static void __init __unflatten_device_tree(const void *fdt,
+ struct dt_device_node **mynodes)
+{
+ unsigned long start, mem, size;
+ struct dt_device_node **allnextp = mynodes;
+
+ dt_dprintk(" -> unflatten_device_tree()\n");
+
+ dt_dprintk("Unflattening device tree:\n");
+ dt_dprintk("magic: %#08x\n", fdt_magic(fdt));
+ dt_dprintk("size: %#08x\n", fdt_totalsize(fdt));
+ dt_dprintk("version: %#08x\n", fdt_version(fdt));
+
+ /* First pass, scan for size */
+ start = ((unsigned long)fdt) + fdt_off_dt_struct(fdt);
+ size = unflatten_dt_node(fdt, 0, &start, NULL, NULL, 0);
+ size = (size | 3) + 1;
+
+ dt_dprintk(" size is %#lx allocating...\n", size);
+
+ /* Allocate memory for the expanded device tree */
+ mem = (unsigned long)_xmalloc (size + 4, __alignof__(struct
dt_device_node));
+
+ ((__be32 *)mem)[size / 4] = cpu_to_be32(0xdeadbeef);
+
+ dt_dprintk(" unflattening %lx...\n", mem);
+
+ /* Second pass, do actual unflattening */
+ start = ((unsigned long)fdt) + fdt_off_dt_struct(fdt);
+ unflatten_dt_node(fdt, mem, &start, NULL, &allnextp, 0);
+ if ( be32_to_cpup((__be32 *)start) != FDT_END )
+ dt_printk(XENLOG_WARNING "Weird tag at end of tree: %08x\n",
+ *((u32 *)start));
+ if ( be32_to_cpu(((__be32 *)mem)[size / 4]) != 0xdeadbeef )
+ dt_printk(XENLOG_WARNING "End of tree marker overwritten: %08x\n",
+ be32_to_cpu(((__be32 *)mem)[size / 4]));
+ *allnextp = NULL;
+
+ dt_dprintk(" <- unflatten_device_tree()\n");
+}
+
+static void dt_alias_add(struct dt_alias_prop *ap,
+ struct dt_device_node *np,
+ int id, const char *stem, int stem_len)
+{
+ ap->np = np;
+ ap->id = id;
+ strlcpy(ap->stem, stem, stem_len + 1);
+ list_add_tail(&ap->link, &aliases_lookup);
+ dt_dprintk("adding DT alias:%s: stem=%s id=%d node=%s\n",
+ ap->alias, ap->stem, ap->id, dt_node_full_name(np));
+}
+
+/**
+ * dt_alias_scan - Scan all properties of 'aliases' node
+ *
+ * The function scans all the properties of 'aliases' node and populate
+ * the the global lookup table with the properties. It returns the
+ * number of alias_prop found, or error code in error case.
+ */
+static void __init dt_alias_scan(void)
+{
+ const struct dt_property *pp;
+ const struct dt_device_node *aliases;
+
+ aliases = dt_find_node_by_path("/aliases");
+ if ( !aliases )
+ return;
+
+ for_each_property_of_node( aliases, pp )
+ {
+ const char *start = pp->name;
+ const char *end = start + strlen(start);
+ struct dt_device_node *np;
+ struct dt_alias_prop *ap;
+ int id, len;
+
+ /* Skip those we do not want to proceed */
+ if ( !strcmp(pp->name, "name") ||
+ !strcmp(pp->name, "phandle") ||
+ !strcmp(pp->name, "linux,phandle") )
+ continue;
+
+ np = dt_find_node_by_path(pp->value);
+ if ( !np )
+ continue;
+
+ /* walk the alias backwards to extract the id and work out
+ * the 'stem' string */
+ while ( isdigit(*(end-1)) && end > start )
+ end--;
+ len = end - start;
+
+ id = simple_strtoll(end, NULL, 10);
+
+ /* Allocate an alias_prop with enough space for the stem */
+ ap = _xmalloc(sizeof(*ap) + len + 1, 4);
+ if ( !ap )
+ continue;
+ ap->alias = start;
+ dt_alias_add(ap, np, id, start, len);
+ }
+}
+
+void __init dt_unflatten_host_device_tree(void)
+{
+ __unflatten_device_tree(device_tree_flattened, &dt_host);
+ dt_alias_scan();
+}
+
/*
* Local variables:
* mode: C
diff --git a/xen/include/xen/device_tree.h b/xen/include/xen/device_tree.h
index 19bda98..015b808 100644
--- a/xen/include/xen/device_tree.h
+++ b/xen/include/xen/device_tree.h
@@ -10,6 +10,10 @@
#ifndef __XEN_DEVICE_TREE_H__
#define __XEN_DEVICE_TREE_H__
+#include <asm/byteorder.h>
+#include <public/xen.h>
+#include <xen/init.h>
+#include <xen/string.h>
#include <xen/types.h>
#define DEVICE_TREE_MAX_DEPTH 16
@@ -52,6 +56,49 @@ struct dt_early_info {
struct dt_module_info modules;
};
+typedef u32 dt_phandle;
+
+/**
+ * dt_property - describe a property for a device
+ * @name: name of the property
+ * @length: size of the value
+ * @value: pointer to data contained in the property
+ * @next: pointer to the next property of a specific node
+ */
+struct dt_property {
+ const char *name;
+ u32 length;
+ void *value;
+ struct dt_property *next;
+};
+
+/**
+ * dt_device_node - describe a node in the device tree
+ * @name: name of the node
+ * @type: type of the node (ie: memory, cpu, ...)
+ * @full_name: full name, it's composed of all the ascendant name separate by /
+ * @used_by: who owns the node? (ie: xen, dom0...)
+ * @properties: list of properties for the node
+ * @child: pointer to the first child
+ * @sibling: pointer to the next sibling
+ * @allnext: pointer to the next in list of all nodes
+ */
+struct dt_device_node {
+ const char *name;
+ const char *type;
+ dt_phandle phandle;
+ char *full_name;
+ domid_t used_by; /* By default it's used by dom0 */
+
+ struct dt_property *properties;
+ struct dt_device_node *parent;
+ struct dt_device_node *child;
+ struct dt_device_node *sibling;
+ struct dt_device_node *next; /* TODO: Remove it. Only use to know the last
children */
+ struct dt_device_node *allnext;
+
+};
+
typedef int (*device_tree_node_func)(const void *fdt,
int node, const char *name, int depth,
u32 address_cells, u32 size_cells,
@@ -77,4 +124,46 @@ int device_tree_for_each_node(const void *fdt,
const char *device_tree_bootargs(const void *fdt);
void device_tree_dump(const void *fdt);
+/**
+ * dt_unflatten_host_device_tree - Unflatten the host device tree
+ *
+ * Create a hierarchical device tree for the host DTB to be able
+ * to retrieve parents.
+ */
+void __init dt_unflatten_host_device_tree(void);
+
+/**
+ * Host device tree
+ * DO NOT modify it!
+ */
+extern struct dt_device_node *dt_host;
+
+#define dt_node_cmp(s1, s2) strcmp((s1), (s2))
+#define dt_compat_cmp(s1, s2, l) strnicmp((s1), (s2), l)
+
+#define for_each_property_of_node(dn, pp) \
+ for ( pp = dn->properties; pp != NULL; pp = pp->next )
+
+#define for_each_device_node(dt, dn) \
+ for ( dn = dt; dn != NULL; dn = dn->allnext )
+
+static inline const char *dt_node_full_name(const struct dt_device_node *np)
+{
+ return (np && np->full_name) ? np->full_name : "<no-node>";
+}
+
+/**
+ * Find a property with a given name for a given node
+ * and return the value.
+ */
+const void *dt_get_property(const struct dt_device_node *np,
+ const char *name, u32 *lenp);
+
+/**
+ * dt_find_node_by_path - Find a node matching a full DT path
+ * @path: The full path to match
+ *
+ * Returns a node pointer.
+ */
+struct dt_device_node *dt_find_node_by_path(const char *path);
#endif
--
1.7.10.4
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