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[46.33.159.2]) by mx.google.com with ESMTPSA id e8sm4080359wic.5.2013.05.10.08.12.29 for (version=TLSv1.2 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Fri, 10 May 2013 08:12:30 -0700 (PDT) From: Julien Grall To: xen-devel@lists.xen.org Cc: Stefano.Stabellini@eu.citrix.com, ian.campbell@citrix.com, patches@linaro.org, Julien Grall Subject: [PATCH V4 05/32] xen/arm: Create a hierarchical device tree Date: Fri, 10 May 2013 16:11:57 +0100 Message-Id: <1368198723-24639-6-git-send-email-julien.grall@linaro.org> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1368198723-24639-1-git-send-email-julien.grall@linaro.org> References: <1368198723-24639-1-git-send-email-julien.grall@linaro.org> X-Gm-Message-State: ALoCoQn9gyabwAKApvyXPYEDZDc6xiIAsTr4Z2BCD6/Le9xBoR/77Zo4CNA3PGzNJTw+mMUyt3w/ X-Original-Sender: julien.grall@linaro.org X-Original-Authentication-Results: mx.google.com; spf=neutral (google.com: 2607:f8b0:400c:c01::233 is neither permitted nor denied by best guess record for domain of patch+caf_=patchwork-forward=linaro.org@linaro.org) smtp.mail=patch+caf_=patchwork-forward=linaro.org@linaro.org Precedence: list Mailing-list: list patchwork-forward@linaro.org; contact patchwork-forward+owners@linaro.org List-ID: X-Google-Group-Id: 836684582541 List-Post: , List-Help: , List-Archive: List-Unsubscribe: , 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 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 Acked-by: Ian Campbell --- 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@kernel.crashing.org * * 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 #include #include +#include +#include #include 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 = ""; + if ( !np->type ) + np->type = ""; + } + 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 +#include +#include +#include #include #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 : ""; +} + +/** + * 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