diff options
Diffstat (limited to 'drivers/firmware/memmap.c')
| -rw-r--r-- | drivers/firmware/memmap.c | 232 |
1 files changed, 232 insertions, 0 deletions
diff --git a/drivers/firmware/memmap.c b/drivers/firmware/memmap.c new file mode 100644 index 0000000..3bf8ee1 --- /dev/null +++ b/drivers/firmware/memmap.c @@ -0,0 +1,232 @@ +/* + * linux/drivers/firmware/memmap.c + * Copyright (C) 2008 SUSE LINUX Products GmbH + * by Bernhard Walle <bwalle@suse.de> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License v2.0 as published by + * the Free Software Foundation + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + */ + +#include <linux/string.h> +#include <linux/firmware-map.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/types.h> +#include <linux/bootmem.h> + +/* + * Data types ------------------------------------------------------------------ + */ + +/* + * Firmware map entry. Because firmware memory maps are flat and not + * hierarchical, it's ok to organise them in a linked list. No parent + * information is necessary as for the resource tree. + */ +struct firmware_map_entry { + resource_size_t start; /* start of the memory range */ + resource_size_t end; /* end of the memory range (incl.) */ + const char *type; /* type of the memory range */ + struct list_head list; /* entry for the linked list */ + struct kobject kobj; /* kobject for each entry */ +}; + +/* + * Forward declarations -------------------------------------------------------- + */ +static ssize_t memmap_attr_show(struct kobject *kobj, + struct attribute *attr, char *buf); +static ssize_t start_show(struct firmware_map_entry *entry, char *buf); +static ssize_t end_show(struct firmware_map_entry *entry, char *buf); +static ssize_t type_show(struct firmware_map_entry *entry, char *buf); + +/* + * Static data ----------------------------------------------------------------- + */ + +struct memmap_attribute { + struct attribute attr; + ssize_t (*show)(struct firmware_map_entry *entry, char *buf); +}; + +struct memmap_attribute memmap_start_attr = __ATTR_RO(start); +struct memmap_attribute memmap_end_attr = __ATTR_RO(end); +struct memmap_attribute memmap_type_attr = __ATTR_RO(type); + +/* + * These are default attributes that are added for every memmap entry. + */ +static struct attribute *def_attrs[] = { + &memmap_start_attr.attr, + &memmap_end_attr.attr, + &memmap_type_attr.attr, + NULL +}; + +static struct sysfs_ops memmap_attr_ops = { + .show = memmap_attr_show, +}; + +static struct kobj_type memmap_ktype = { + .sysfs_ops = &memmap_attr_ops, + .default_attrs = def_attrs, +}; + +/* + * Registration functions ------------------------------------------------------ + */ + +/* + * Firmware memory map entries. No locking is needed because the + * firmware_map_add() and firmware_map_add_early() functions are called + * in firmware initialisation code in one single thread of execution. + */ +static LIST_HEAD(map_entries); + +/** + * firmware_map_add_entry() - Does the real work to add a firmware memmap entry. + * @start: Start of the memory range. + * @end: End of the memory range (inclusive). + * @type: Type of the memory range. + * @entry: Pre-allocated (either kmalloc() or bootmem allocator), uninitialised + * entry. + * + * Common implementation of firmware_map_add() and firmware_map_add_early() + * which expects a pre-allocated struct firmware_map_entry. + **/ +static int firmware_map_add_entry(resource_size_t start, resource_size_t end, + const char *type, + struct firmware_map_entry *entry) +{ + BUG_ON(start > end); + + entry->start = start; + entry->end = end; + entry->type = type; + INIT_LIST_HEAD(&entry->list); + kobject_init(&entry->kobj, &memmap_ktype); + + list_add_tail(&entry->list, &map_entries); + + return 0; +} + +/** + * firmware_map_add() - Adds a firmware mapping entry. + * @start: Start of the memory range. + * @end: End of the memory range (inclusive). + * @type: Type of the memory range. + * + * This function uses kmalloc() for memory + * allocation. Use firmware_map_add_early() if you want to use the bootmem + * allocator. + * + * That function must be called before late_initcall. + * + * Returns 0 on success, or -ENOMEM if no memory could be allocated. + **/ +int firmware_map_add(resource_size_t start, resource_size_t end, + const char *type) +{ + struct firmware_map_entry *entry; + + entry = kmalloc(sizeof(struct firmware_map_entry), GFP_ATOMIC); + if (!entry) + return -ENOMEM; + + return firmware_map_add_entry(start, end, type, entry); +} + +/** + * firmware_map_add_early() - Adds a firmware mapping entry. + * @start: Start of the memory range. + * @end: End of the memory range (inclusive). + * @type: Type of the memory range. + * + * Adds a firmware mapping entry. This function uses the bootmem allocator + * for memory allocation. Use firmware_map_add() if you want to use kmalloc(). + * + * That function must be called before late_initcall. + * + * Returns 0 on success, or -ENOMEM if no memory could be allocated. + **/ +int __init firmware_map_add_early(resource_size_t start, resource_size_t end, + const char *type) +{ + struct firmware_map_entry *entry; + + entry = alloc_bootmem_low(sizeof(struct firmware_map_entry)); + if (WARN_ON(!entry)) + return -ENOMEM; + + return firmware_map_add_entry(start, end, type, entry); +} + +/* + * Sysfs functions ------------------------------------------------------------- + */ + +static ssize_t start_show(struct firmware_map_entry *entry, char *buf) +{ + return snprintf(buf, PAGE_SIZE, "0x%llx\n", + (unsigned long long)entry->start); +} + +static ssize_t end_show(struct firmware_map_entry *entry, char *buf) +{ + return snprintf(buf, PAGE_SIZE, "0x%llx\n", + (unsigned long long)entry->end); +} + +static ssize_t type_show(struct firmware_map_entry *entry, char *buf) +{ + return snprintf(buf, PAGE_SIZE, "%s\n", entry->type); +} + +#define to_memmap_attr(_attr) container_of(_attr, struct memmap_attribute, attr) +#define to_memmap_entry(obj) container_of(obj, struct firmware_map_entry, kobj) + +static ssize_t memmap_attr_show(struct kobject *kobj, + struct attribute *attr, char *buf) +{ + struct firmware_map_entry *entry = to_memmap_entry(kobj); + struct memmap_attribute *memmap_attr = to_memmap_attr(attr); + + return memmap_attr->show(entry, buf); +} + +/* + * Initialises stuff and adds the entries in the map_entries list to + * sysfs. Important is that firmware_map_add() and firmware_map_add_early() + * must be called before late_initcall. That's just because that function + * is called as late_initcall() function, which means that if you call + * firmware_map_add() or firmware_map_add_early() afterwards, the entries + * are not added to sysfs. + */ +static int __init memmap_init(void) +{ + int i = 0; + struct firmware_map_entry *entry; + struct kset *memmap_kset; + + memmap_kset = kset_create_and_add("memmap", NULL, firmware_kobj); + if (WARN_ON(!memmap_kset)) + return -ENOMEM; + + list_for_each_entry(entry, &map_entries, list) { + entry->kobj.kset = memmap_kset; + if (kobject_add(&entry->kobj, NULL, "%d", i++)) + kobject_put(&entry->kobj); + } + + return 0; +} +late_initcall(memmap_init); + |
