| /* |
| * linux/kernel/resource.c |
| * |
| * Copyright (C) 1999 Linus Torvalds |
| * Copyright (C) 1999 Martin Mares <mj@ucw.cz> |
| * |
| * Arbitrary resource management. |
| */ |
| |
| #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| |
| #include <linux/export.h> |
| #include <linux/errno.h> |
| #include <linux/ioport.h> |
| #include <linux/init.h> |
| #include <linux/slab.h> |
| #include <linux/spinlock.h> |
| #include <linux/fs.h> |
| #include <linux/proc_fs.h> |
| #include <linux/sched.h> |
| #include <linux/seq_file.h> |
| #include <linux/device.h> |
| #include <linux/pfn.h> |
| #include <linux/mm.h> |
| #include <linux/resource_ext.h> |
| #include <asm/io.h> |
| |
| |
| struct resource ioport_resource = { |
| .name = "PCI IO", |
| .start = 0, |
| .end = IO_SPACE_LIMIT, |
| .flags = IORESOURCE_IO, |
| }; |
| EXPORT_SYMBOL(ioport_resource); |
| |
| struct resource iomem_resource = { |
| .name = "PCI mem", |
| .start = 0, |
| .end = -1, |
| .flags = IORESOURCE_MEM, |
| }; |
| EXPORT_SYMBOL(iomem_resource); |
| |
| /* constraints to be met while allocating resources */ |
| struct resource_constraint { |
| resource_size_t min, max, align; |
| resource_size_t (*alignf)(void *, const struct resource *, |
| resource_size_t, resource_size_t); |
| void *alignf_data; |
| }; |
| |
| static DEFINE_RWLOCK(resource_lock); |
| |
| /* |
| * For memory hotplug, there is no way to free resource entries allocated |
| * by boot mem after the system is up. So for reusing the resource entry |
| * we need to remember the resource. |
| */ |
| static struct resource *bootmem_resource_free; |
| static DEFINE_SPINLOCK(bootmem_resource_lock); |
| |
| static struct resource *next_resource(struct resource *p, bool sibling_only) |
| { |
| /* Caller wants to traverse through siblings only */ |
| if (sibling_only) |
| return p->sibling; |
| |
| if (p->child) |
| return p->child; |
| while (!p->sibling && p->parent) |
| p = p->parent; |
| return p->sibling; |
| } |
| |
| static void *r_next(struct seq_file *m, void *v, loff_t *pos) |
| { |
| struct resource *p = v; |
| (*pos)++; |
| return (void *)next_resource(p, false); |
| } |
| |
| #ifdef CONFIG_PROC_FS |
| |
| enum { MAX_IORES_LEVEL = 5 }; |
| |
| static void *r_start(struct seq_file *m, loff_t *pos) |
| __acquires(resource_lock) |
| { |
| struct resource *p = m->private; |
| loff_t l = 0; |
| read_lock(&resource_lock); |
| for (p = p->child; p && l < *pos; p = r_next(m, p, &l)) |
| ; |
| return p; |
| } |
| |
| static void r_stop(struct seq_file *m, void *v) |
| __releases(resource_lock) |
| { |
| read_unlock(&resource_lock); |
| } |
| |
| static int r_show(struct seq_file *m, void *v) |
| { |
| struct resource *root = m->private; |
| struct resource *r = v, *p; |
| int width = root->end < 0x10000 ? 4 : 8; |
| int depth; |
| |
| for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent) |
| if (p->parent == root) |
| break; |
| seq_printf(m, "%*s%0*llx-%0*llx : %s\n", |
| depth * 2, "", |
| width, (unsigned long long) r->start, |
| width, (unsigned long long) r->end, |
| r->name ? r->name : "<BAD>"); |
| return 0; |
| } |
| |
| static const struct seq_operations resource_op = { |
| .start = r_start, |
| .next = r_next, |
| .stop = r_stop, |
| .show = r_show, |
| }; |
| |
| static int ioports_open(struct inode *inode, struct file *file) |
| { |
| int res = seq_open(file, &resource_op); |
| if (!res) { |
| struct seq_file *m = file->private_data; |
| m->private = &ioport_resource; |
| } |
| return res; |
| } |
| |
| static int iomem_open(struct inode *inode, struct file *file) |
| { |
| int res = seq_open(file, &resource_op); |
| if (!res) { |
| struct seq_file *m = file->private_data; |
| m->private = &iomem_resource; |
| } |
| return res; |
| } |
| |
| static const struct file_operations proc_ioports_operations = { |
| .open = ioports_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = seq_release, |
| }; |
| |
| static const struct file_operations proc_iomem_operations = { |
| .open = iomem_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = seq_release, |
| }; |
| |
| static int __init ioresources_init(void) |
| { |
| proc_create("ioports", 0, NULL, &proc_ioports_operations); |
| proc_create("iomem", 0, NULL, &proc_iomem_operations); |
| return 0; |
| } |
| __initcall(ioresources_init); |
| |
| #endif /* CONFIG_PROC_FS */ |
| |
| static void free_resource(struct resource *res) |
| { |
| if (!res) |
| return; |
| |
| if (!PageSlab(virt_to_head_page(res))) { |
| spin_lock(&bootmem_resource_lock); |
| res->sibling = bootmem_resource_free; |
| bootmem_resource_free = res; |
| spin_unlock(&bootmem_resource_lock); |
| } else { |
| kfree(res); |
| } |
| } |
| |
| static struct resource *alloc_resource(gfp_t flags) |
| { |
| struct resource *res = NULL; |
| |
| spin_lock(&bootmem_resource_lock); |
| if (bootmem_resource_free) { |
| res = bootmem_resource_free; |
| bootmem_resource_free = res->sibling; |
| } |
| spin_unlock(&bootmem_resource_lock); |
| |
| if (res) |
| memset(res, 0, sizeof(struct resource)); |
| else |
| res = kzalloc(sizeof(struct resource), flags); |
| |
| return res; |
| } |
| |
| /* Return the conflict entry if you can't request it */ |
| static struct resource * __request_resource(struct resource *root, struct resource *new) |
| { |
| resource_size_t start = new->start; |
| resource_size_t end = new->end; |
| struct resource *tmp, **p; |
| |
| if (end < start) |
| return root; |
| if (start < root->start) |
| return root; |
| if (end > root->end) |
| return root; |
| p = &root->child; |
| for (;;) { |
| tmp = *p; |
| if (!tmp || tmp->start > end) { |
| new->sibling = tmp; |
| *p = new; |
| new->parent = root; |
| return NULL; |
| } |
| p = &tmp->sibling; |
| if (tmp->end < start) |
| continue; |
| return tmp; |
| } |
| } |
| |
| static int __release_resource(struct resource *old) |
| { |
| struct resource *tmp, **p; |
| |
| p = &old->parent->child; |
| for (;;) { |
| tmp = *p; |
| if (!tmp) |
| break; |
| if (tmp == old) { |
| *p = tmp->sibling; |
| old->parent = NULL; |
| return 0; |
| } |
| p = &tmp->sibling; |
| } |
| return -EINVAL; |
| } |
| |
| static void __release_child_resources(struct resource *r) |
| { |
| struct resource *tmp, *p; |
| resource_size_t size; |
| |
| p = r->child; |
| r->child = NULL; |
| while (p) { |
| tmp = p; |
| p = p->sibling; |
| |
| tmp->parent = NULL; |
| tmp->sibling = NULL; |
| __release_child_resources(tmp); |
| |
| printk(KERN_DEBUG "release child resource %pR\n", tmp); |
| /* need to restore size, and keep flags */ |
| size = resource_size(tmp); |
| tmp->start = 0; |
| tmp->end = size - 1; |
| } |
| } |
| |
| void release_child_resources(struct resource *r) |
| { |
| write_lock(&resource_lock); |
| __release_child_resources(r); |
| write_unlock(&resource_lock); |
| } |
| |
| /** |
| * request_resource_conflict - request and reserve an I/O or memory resource |
| * @root: root resource descriptor |
| * @new: resource descriptor desired by caller |
| * |
| * Returns 0 for success, conflict resource on error. |
| */ |
| struct resource *request_resource_conflict(struct resource *root, struct resource *new) |
| { |
| struct resource *conflict; |
| |
| write_lock(&resource_lock); |
| conflict = __request_resource(root, new); |
| write_unlock(&resource_lock); |
| return conflict; |
| } |
| |
| /** |
| * request_resource - request and reserve an I/O or memory resource |
| * @root: root resource descriptor |
| * @new: resource descriptor desired by caller |
| * |
| * Returns 0 for success, negative error code on error. |
| */ |
| int request_resource(struct resource *root, struct resource *new) |
| { |
| struct resource *conflict; |
| |
| conflict = request_resource_conflict(root, new); |
| return conflict ? -EBUSY : 0; |
| } |
| |
| EXPORT_SYMBOL(request_resource); |
| |
| /** |
| * release_resource - release a previously reserved resource |
| * @old: resource pointer |
| */ |
| int release_resource(struct resource *old) |
| { |
| int retval; |
| |
| write_lock(&resource_lock); |
| retval = __release_resource(old); |
| write_unlock(&resource_lock); |
| return retval; |
| } |
| |
| EXPORT_SYMBOL(release_resource); |
| |
| /* |
| * Finds the lowest iomem resource existing within [res->start.res->end). |
| * The caller must specify res->start, res->end, res->flags, and optionally |
| * desc. If found, returns 0, res is overwritten, if not found, returns -1. |
| * This function walks the whole tree and not just first level children until |
| * and unless first_level_children_only is true. |
| */ |
| static int find_next_iomem_res(struct resource *res, unsigned long desc, |
| bool first_level_children_only) |
| { |
| resource_size_t start, end; |
| struct resource *p; |
| bool sibling_only = false; |
| |
| BUG_ON(!res); |
| |
| start = res->start; |
| end = res->end; |
| BUG_ON(start >= end); |
| |
| if (first_level_children_only) |
| sibling_only = true; |
| |
| read_lock(&resource_lock); |
| |
| for (p = iomem_resource.child; p; p = next_resource(p, sibling_only)) { |
| if ((p->flags & res->flags) != res->flags) |
| continue; |
| if ((desc != IORES_DESC_NONE) && (desc != p->desc)) |
| continue; |
| if (p->start > end) { |
| p = NULL; |
| break; |
| } |
| if ((p->end >= start) && (p->start < end)) |
| break; |
| } |
| |
| read_unlock(&resource_lock); |
| if (!p) |
| return -1; |
| /* copy data */ |
| if (res->start < p->start) |
| res->start = p->start; |
| if (res->end > p->end) |
| res->end = p->end; |
| return 0; |
| } |
| |
| /* |
| * Walks through iomem resources and calls func() with matching resource |
| * ranges. This walks through whole tree and not just first level children. |
| * All the memory ranges which overlap start,end and also match flags and |
| * desc are valid candidates. |
| * |
| * @desc: I/O resource descriptor. Use IORES_DESC_NONE to skip @desc check. |
| * @flags: I/O resource flags |
| * @start: start addr |
| * @end: end addr |
| * |
| * NOTE: For a new descriptor search, define a new IORES_DESC in |
| * <linux/ioport.h> and set it in 'desc' of a target resource entry. |
| */ |
| int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start, |
| u64 end, void *arg, int (*func)(u64, u64, void *)) |
| { |
| struct resource res; |
| u64 orig_end; |
| int ret = -1; |
| |
| res.start = start; |
| res.end = end; |
| res.flags = flags; |
| orig_end = res.end; |
| |
| while ((res.start < res.end) && |
| (!find_next_iomem_res(&res, desc, false))) { |
| |
| ret = (*func)(res.start, res.end, arg); |
| if (ret) |
| break; |
| |
| res.start = res.end + 1; |
| res.end = orig_end; |
| } |
| |
| return ret; |
| } |
| |
| /* |
| * This function calls the @func callback against all memory ranges of type |
| * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY. |
| * Now, this function is only for System RAM, it deals with full ranges and |
| * not PFNs. If resources are not PFN-aligned, dealing with PFNs can truncate |
| * ranges. |
| */ |
| int walk_system_ram_res(u64 start, u64 end, void *arg, |
| int (*func)(u64, u64, void *)) |
| { |
| struct resource res; |
| u64 orig_end; |
| int ret = -1; |
| |
| res.start = start; |
| res.end = end; |
| res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; |
| orig_end = res.end; |
| while ((res.start < res.end) && |
| (!find_next_iomem_res(&res, IORES_DESC_NONE, true))) { |
| ret = (*func)(res.start, res.end, arg); |
| if (ret) |
| break; |
| res.start = res.end + 1; |
| res.end = orig_end; |
| } |
| return ret; |
| } |
| |
| #if !defined(CONFIG_ARCH_HAS_WALK_MEMORY) |
| |
| /* |
| * This function calls the @func callback against all memory ranges of type |
| * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY. |
| * It is to be used only for System RAM. |
| */ |
| int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages, |
| void *arg, int (*func)(unsigned long, unsigned long, void *)) |
| { |
| struct resource res; |
| unsigned long pfn, end_pfn; |
| u64 orig_end; |
| int ret = -1; |
| |
| res.start = (u64) start_pfn << PAGE_SHIFT; |
| res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1; |
| res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; |
| orig_end = res.end; |
| while ((res.start < res.end) && |
| (find_next_iomem_res(&res, IORES_DESC_NONE, true) >= 0)) { |
| pfn = (res.start + PAGE_SIZE - 1) >> PAGE_SHIFT; |
| end_pfn = (res.end + 1) >> PAGE_SHIFT; |
| if (end_pfn > pfn) |
| ret = (*func)(pfn, end_pfn - pfn, arg); |
| if (ret) |
| break; |
| res.start = res.end + 1; |
| res.end = orig_end; |
| } |
| return ret; |
| } |
| |
| #endif |
| |
| static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg) |
| { |
| return 1; |
| } |
| /* |
| * This generic page_is_ram() returns true if specified address is |
| * registered as System RAM in iomem_resource list. |
| */ |
| int __weak page_is_ram(unsigned long pfn) |
| { |
| return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1; |
| } |
| EXPORT_SYMBOL_GPL(page_is_ram); |
| |
| /** |
| * region_intersects() - determine intersection of region with known resources |
| * @start: region start address |
| * @size: size of region |
| * @flags: flags of resource (in iomem_resource) |
| * @desc: descriptor of resource (in iomem_resource) or IORES_DESC_NONE |
| * |
| * Check if the specified region partially overlaps or fully eclipses a |
| * resource identified by @flags and @desc (optional with IORES_DESC_NONE). |
| * Return REGION_DISJOINT if the region does not overlap @flags/@desc, |
| * return REGION_MIXED if the region overlaps @flags/@desc and another |
| * resource, and return REGION_INTERSECTS if the region overlaps @flags/@desc |
| * and no other defined resource. Note that REGION_INTERSECTS is also |
| * returned in the case when the specified region overlaps RAM and undefined |
| * memory holes. |
| * |
| * region_intersect() is used by memory remapping functions to ensure |
| * the user is not remapping RAM and is a vast speed up over walking |
| * through the resource table page by page. |
| */ |
| int region_intersects(resource_size_t start, size_t size, unsigned long flags, |
| unsigned long desc) |
| { |
| resource_size_t end = start + size - 1; |
| int type = 0; int other = 0; |
| struct resource *p; |
| |
| read_lock(&resource_lock); |
| for (p = iomem_resource.child; p ; p = p->sibling) { |
| bool is_type = (((p->flags & flags) == flags) && |
| ((desc == IORES_DESC_NONE) || |
| (desc == p->desc))); |
| |
| if (start >= p->start && start <= p->end) |
| is_type ? type++ : other++; |
| if (end >= p->start && end <= p->end) |
| is_type ? type++ : other++; |
| if (p->start >= start && p->end <= end) |
| is_type ? type++ : other++; |
| } |
| read_unlock(&resource_lock); |
| |
| if (other == 0) |
| return type ? REGION_INTERSECTS : REGION_DISJOINT; |
| |
| if (type) |
| return REGION_MIXED; |
| |
| return REGION_DISJOINT; |
| } |
| EXPORT_SYMBOL_GPL(region_intersects); |
| |
| void __weak arch_remove_reservations(struct resource *avail) |
| { |
| } |
| |
| static resource_size_t simple_align_resource(void *data, |
| const struct resource *avail, |
| resource_size_t size, |
| resource_size_t align) |
| { |
| return avail->start; |
| } |
| |
| static void resource_clip(struct resource *res, resource_size_t min, |
| resource_size_t max) |
| { |
| if (res->start < min) |
| res->start = min; |
| if (res->end > max) |
| res->end = max; |
| } |
| |
| /* |
| * Find empty slot in the resource tree with the given range and |
| * alignment constraints |
| */ |
| static int __find_resource(struct resource *root, struct resource *old, |
| struct resource *new, |
| resource_size_t size, |
| struct resource_constraint *constraint) |
| { |
| struct resource *this = root->child; |
| struct resource tmp = *new, avail, alloc; |
| |
| tmp.start = root->start; |
| /* |
| * Skip past an allocated resource that starts at 0, since the assignment |
| * of this->start - 1 to tmp->end below would cause an underflow. |
| */ |
| if (this && this->start == root->start) { |
| tmp.start = (this == old) ? old->start : this->end + 1; |
| this = this->sibling; |
| } |
| for(;;) { |
| if (this) |
| tmp.end = (this == old) ? this->end : this->start - 1; |
| else |
| tmp.end = root->end; |
| |
| if (tmp.end < tmp.start) |
| goto next; |
| |
| resource_clip(&tmp, constraint->min, constraint->max); |
| arch_remove_reservations(&tmp); |
| |
| /* Check for overflow after ALIGN() */ |
| avail.start = ALIGN(tmp.start, constraint->align); |
| avail.end = tmp.end; |
| avail.flags = new->flags & ~IORESOURCE_UNSET; |
| if (avail.start >= tmp.start) { |
| alloc.flags = avail.flags; |
| alloc.start = constraint->alignf(constraint->alignf_data, &avail, |
| size, constraint->align); |
| alloc.end = alloc.start + size - 1; |
| if (resource_contains(&avail, &alloc)) { |
| new->start = alloc.start; |
| new->end = alloc.end; |
| return 0; |
| } |
| } |
| |
| next: if (!this || this->end == root->end) |
| break; |
| |
| if (this != old) |
| tmp.start = this->end + 1; |
| this = this->sibling; |
| } |
| return -EBUSY; |
| } |
| |
| /* |
| * Find empty slot in the resource tree given range and alignment. |
| */ |
| static int find_resource(struct resource *root, struct resource *new, |
| resource_size_t size, |
| struct resource_constraint *constraint) |
| { |
| return __find_resource(root, NULL, new, size, constraint); |
| } |
| |
| /** |
| * reallocate_resource - allocate a slot in the resource tree given range & alignment. |
| * The resource will be relocated if the new size cannot be reallocated in the |
| * current location. |
| * |
| * @root: root resource descriptor |
| * @old: resource descriptor desired by caller |
| * @newsize: new size of the resource descriptor |
| * @constraint: the size and alignment constraints to be met. |
| */ |
| static int reallocate_resource(struct resource *root, struct resource *old, |
| resource_size_t newsize, |
| struct resource_constraint *constraint) |
| { |
| int err=0; |
| struct resource new = *old; |
| struct resource *conflict; |
| |
| write_lock(&resource_lock); |
| |
| if ((err = __find_resource(root, old, &new, newsize, constraint))) |
| goto out; |
| |
| if (resource_contains(&new, old)) { |
| old->start = new.start; |
| old->end = new.end; |
| goto out; |
| } |
| |
| if (old->child) { |
| err = -EBUSY; |
| goto out; |
| } |
| |
| if (resource_contains(old, &new)) { |
| old->start = new.start; |
| old->end = new.end; |
| } else { |
| __release_resource(old); |
| *old = new; |
| conflict = __request_resource(root, old); |
| BUG_ON(conflict); |
| } |
| out: |
| write_unlock(&resource_lock); |
| return err; |
| } |
| |
| |
| /** |
| * allocate_resource - allocate empty slot in the resource tree given range & alignment. |
| * The resource will be reallocated with a new size if it was already allocated |
| * @root: root resource descriptor |
| * @new: resource descriptor desired by caller |
| * @size: requested resource region size |
| * @min: minimum boundary to allocate |
| * @max: maximum boundary to allocate |
| * @align: alignment requested, in bytes |
| * @alignf: alignment function, optional, called if not NULL |
| * @alignf_data: arbitrary data to pass to the @alignf function |
| */ |
| int allocate_resource(struct resource *root, struct resource *new, |
| resource_size_t size, resource_size_t min, |
| resource_size_t max, resource_size_t align, |
| resource_size_t (*alignf)(void *, |
| const struct resource *, |
| resource_size_t, |
| resource_size_t), |
| void *alignf_data) |
| { |
| int err; |
| struct resource_constraint constraint; |
| |
| if (!alignf) |
| alignf = simple_align_resource; |
| |
| constraint.min = min; |
| constraint.max = max; |
| constraint.align = align; |
| constraint.alignf = alignf; |
| constraint.alignf_data = alignf_data; |
| |
| if ( new->parent ) { |
| /* resource is already allocated, try reallocating with |
| the new constraints */ |
| return reallocate_resource(root, new, size, &constraint); |
| } |
| |
| write_lock(&resource_lock); |
| err = find_resource(root, new, size, &constraint); |
| if (err >= 0 && __request_resource(root, new)) |
| err = -EBUSY; |
| write_unlock(&resource_lock); |
| return err; |
| } |
| |
| EXPORT_SYMBOL(allocate_resource); |
| |
| /** |
| * lookup_resource - find an existing resource by a resource start address |
| * @root: root resource descriptor |
| * @start: resource start address |
| * |
| * Returns a pointer to the resource if found, NULL otherwise |
| */ |
| struct resource *lookup_resource(struct resource *root, resource_size_t start) |
| { |
| struct resource *res; |
| |
| read_lock(&resource_lock); |
| for (res = root->child; res; res = res->sibling) { |
| if (res->start == start) |
| break; |
| } |
| read_unlock(&resource_lock); |
| |
| return res; |
| } |
| |
| /* |
| * Insert a resource into the resource tree. If successful, return NULL, |
| * otherwise return the conflicting resource (compare to __request_resource()) |
| */ |
| static struct resource * __insert_resource(struct resource *parent, struct resource *new) |
| { |
| struct resource *first, *next; |
| |
| for (;; parent = first) { |
| first = __request_resource(parent, new); |
| if (!first) |
| return first; |
| |
| if (first == parent) |
| return first; |
| if (WARN_ON(first == new)) /* duplicated insertion */ |
| return first; |
| |
| if ((first->start > new->start) || (first->end < new->end)) |
| break; |
| if ((first->start == new->start) && (first->end == new->end)) |
| break; |
| } |
| |
| for (next = first; ; next = next->sibling) { |
| /* Partial overlap? Bad, and unfixable */ |
| if (next->start < new->start || next->end > new->end) |
| return next; |
| if (!next->sibling) |
| break; |
| if (next->sibling->start > new->end) |
| break; |
| } |
| |
| new->parent = parent; |
| new->sibling = next->sibling; |
| new->child = first; |
| |
| next->sibling = NULL; |
| for (next = first; next; next = next->sibling) |
| next->parent = new; |
| |
| if (parent->child == first) { |
| parent->child = new; |
| } else { |
| next = parent->child; |
| while (next->sibling != first) |
| next = next->sibling; |
| next->sibling = new; |
| } |
| return NULL; |
| } |
| |
| /** |
| * insert_resource_conflict - Inserts resource in the resource tree |
| * @parent: parent of the new resource |
| * @new: new resource to insert |
| * |
| * Returns 0 on success, conflict resource if the resource can't be inserted. |
| * |
| * This function is equivalent to request_resource_conflict when no conflict |
| * happens. If a conflict happens, and the conflicting resources |
| * entirely fit within the range of the new resource, then the new |
| * resource is inserted and the conflicting resources become children of |
| * the new resource. |
| */ |
| struct resource *insert_resource_conflict(struct resource *parent, struct resource *new) |
| { |
| struct resource *conflict; |
| |
| write_lock(&resource_lock); |
| conflict = __insert_resource(parent, new); |
| write_unlock(&resource_lock); |
| return conflict; |
| } |
| |
| /** |
| * insert_resource - Inserts a resource in the resource tree |
| * @parent: parent of the new resource |
| * @new: new resource to insert |
| * |
| * Returns 0 on success, -EBUSY if the resource can't be inserted. |
| */ |
| int insert_resource(struct resource *parent, struct resource *new) |
| { |
| struct resource *conflict; |
| |
| conflict = insert_resource_conflict(parent, new); |
| return conflict ? -EBUSY : 0; |
| } |
| |
| /** |
| * insert_resource_expand_to_fit - Insert a resource into the resource tree |
| * @root: root resource descriptor |
| * @new: new resource to insert |
| * |
| * Insert a resource into the resource tree, possibly expanding it in order |
| * to make it encompass any conflicting resources. |
| */ |
| void insert_resource_expand_to_fit(struct resource *root, struct resource *new) |
| { |
| if (new->parent) |
| return; |
| |
| write_lock(&resource_lock); |
| for (;;) { |
| struct resource *conflict; |
| |
| conflict = __insert_resource(root, new); |
| if (!conflict) |
| break; |
| if (conflict == root) |
| break; |
| |
| /* Ok, expand resource to cover the conflict, then try again .. */ |
| if (conflict->start < new->start) |
| new->start = conflict->start; |
| if (conflict->end > new->end) |
| new->end = conflict->end; |
| |
| printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name); |
| } |
| write_unlock(&resource_lock); |
| } |
| |
| static int __adjust_resource(struct resource *res, resource_size_t start, |
| resource_size_t size) |
| { |
| struct resource *tmp, *parent = res->parent; |
| resource_size_t end = start + size - 1; |
| int result = -EBUSY; |
| |
| if (!parent) |
| goto skip; |
| |
| if ((start < parent->start) || (end > parent->end)) |
| goto out; |
| |
| if (res->sibling && (res->sibling->start <= end)) |
| goto out; |
| |
| tmp = parent->child; |
| if (tmp != res) { |
| while (tmp->sibling != res) |
| tmp = tmp->sibling; |
| if (start <= tmp->end) |
| goto out; |
| } |
| |
| skip: |
| for (tmp = res->child; tmp; tmp = tmp->sibling) |
| if ((tmp->start < start) || (tmp->end > end)) |
| goto out; |
| |
| res->start = start; |
| res->end = end; |
| result = 0; |
| |
| out: |
| return result; |
| } |
| |
| /** |
| * adjust_resource - modify a resource's start and size |
| * @res: resource to modify |
| * @start: new start value |
| * @size: new size |
| * |
| * Given an existing resource, change its start and size to match the |
| * arguments. Returns 0 on success, -EBUSY if it can't fit. |
| * Existing children of the resource are assumed to be immutable. |
| */ |
| int adjust_resource(struct resource *res, resource_size_t start, |
| resource_size_t size) |
| { |
| int result; |
| |
| write_lock(&resource_lock); |
| result = __adjust_resource(res, start, size); |
| write_unlock(&resource_lock); |
| return result; |
| } |
| EXPORT_SYMBOL(adjust_resource); |
| |
| static void __init __reserve_region_with_split(struct resource *root, |
| resource_size_t start, resource_size_t end, |
| const char *name) |
| { |
| struct resource *parent = root; |
| struct resource *conflict; |
| struct resource *res = alloc_resource(GFP_ATOMIC); |
| struct resource *next_res = NULL; |
| |
| if (!res) |
| return; |
| |
| res->name = name; |
| res->start = start; |
| res->end = end; |
| res->flags = IORESOURCE_BUSY; |
| res->desc = IORES_DESC_NONE; |
| |
| while (1) { |
| |
| conflict = __request_resource(parent, res); |
| if (!conflict) { |
| if (!next_res) |
| break; |
| res = next_res; |
| next_res = NULL; |
| continue; |
| } |
| |
| /* conflict covered whole area */ |
| if (conflict->start <= res->start && |
| conflict->end >= res->end) { |
| free_resource(res); |
| WARN_ON(next_res); |
| break; |
| } |
| |
| /* failed, split and try again */ |
| if (conflict->start > res->start) { |
| end = res->end; |
| res->end = conflict->start - 1; |
| if (conflict->end < end) { |
| next_res = alloc_resource(GFP_ATOMIC); |
| if (!next_res) { |
| free_resource(res); |
| break; |
| } |
| next_res->name = name; |
| next_res->start = conflict->end + 1; |
| next_res->end = end; |
| next_res->flags = IORESOURCE_BUSY; |
| next_res->desc = IORES_DESC_NONE; |
| } |
| } else { |
| res->start = conflict->end + 1; |
| } |
| } |
| |
| } |
| |
| void __init reserve_region_with_split(struct resource *root, |
| resource_size_t start, resource_size_t end, |
| const char *name) |
| { |
| int abort = 0; |
| |
| write_lock(&resource_lock); |
| if (root->start > start || root->end < end) { |
| pr_err("requested range [0x%llx-0x%llx] not in root %pr\n", |
| (unsigned long long)start, (unsigned long long)end, |
| root); |
| if (start > root->end || end < root->start) |
| abort = 1; |
| else { |
| if (end > root->end) |
| end = root->end; |
| if (start < root->start) |
| start = root->start; |
| pr_err("fixing request to [0x%llx-0x%llx]\n", |
| (unsigned long long)start, |
| (unsigned long long)end); |
| } |
| dump_stack(); |
| } |
| if (!abort) |
| __reserve_region_with_split(root, start, end, name); |
| write_unlock(&resource_lock); |
| } |
| |
| /** |
| * resource_alignment - calculate resource's alignment |
| * @res: resource pointer |
| * |
| * Returns alignment on success, 0 (invalid alignment) on failure. |
| */ |
| resource_size_t resource_alignment(struct resource *res) |
| { |
| switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) { |
| case IORESOURCE_SIZEALIGN: |
| return resource_size(res); |
| case IORESOURCE_STARTALIGN: |
| return res->start; |
| default: |
| return 0; |
| } |
| } |
| |
| /* |
| * This is compatibility stuff for IO resources. |
| * |
| * Note how this, unlike the above, knows about |
| * the IO flag meanings (busy etc). |
| * |
| * request_region creates a new busy region. |
| * |
| * release_region releases a matching busy region. |
| */ |
| |
| static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait); |
| |
| /** |
| * __request_region - create a new busy resource region |
| * @parent: parent resource descriptor |
| * @start: resource start address |
| * @n: resource region size |
| * @name: reserving caller's ID string |
| * @flags: IO resource flags |
| */ |
| struct resource * __request_region(struct resource *parent, |
| resource_size_t start, resource_size_t n, |
| const char *name, int flags) |
| { |
| DECLARE_WAITQUEUE(wait, current); |
| struct resource *res = alloc_resource(GFP_KERNEL); |
| |
| if (!res) |
| return NULL; |
| |
| res->name = name; |
| res->start = start; |
| res->end = start + n - 1; |
| res->flags = resource_type(parent) | resource_ext_type(parent); |
| res->flags |= IORESOURCE_BUSY | flags; |
| res->desc = IORES_DESC_NONE; |
| |
| write_lock(&resource_lock); |
| |
| for (;;) { |
| struct resource *conflict; |
| |
| conflict = __request_resource(parent, res); |
| if (!conflict) |
| break; |
| if (conflict != parent) { |
| if (!(conflict->flags & IORESOURCE_BUSY)) { |
| parent = conflict; |
| continue; |
| } |
| } |
| if (conflict->flags & flags & IORESOURCE_MUXED) { |
| add_wait_queue(&muxed_resource_wait, &wait); |
| write_unlock(&resource_lock); |
| set_current_state(TASK_UNINTERRUPTIBLE); |
| schedule(); |
| remove_wait_queue(&muxed_resource_wait, &wait); |
| write_lock(&resource_lock); |
| continue; |
| } |
| /* Uhhuh, that didn't work out.. */ |
| free_resource(res); |
| res = NULL; |
| break; |
| } |
| write_unlock(&resource_lock); |
| return res; |
| } |
| EXPORT_SYMBOL(__request_region); |
| |
| /** |
| * __release_region - release a previously reserved resource region |
| * @parent: parent resource descriptor |
| * @start: resource start address |
| * @n: resource region size |
| * |
| * The described resource region must match a currently busy region. |
| */ |
| void __release_region(struct resource *parent, resource_size_t start, |
| resource_size_t n) |
| { |
| struct resource **p; |
| resource_size_t end; |
| |
| p = &parent->child; |
| end = start + n - 1; |
| |
| write_lock(&resource_lock); |
| |
| for (;;) { |
| struct resource *res = *p; |
| |
| if (!res) |
| break; |
| if (res->start <= start && res->end >= end) { |
| if (!(res->flags & IORESOURCE_BUSY)) { |
| p = &res->child; |
| continue; |
| } |
| if (res->start != start || res->end != end) |
| break; |
| *p = res->sibling; |
| write_unlock(&resource_lock); |
| if (res->flags & IORESOURCE_MUXED) |
| wake_up(&muxed_resource_wait); |
| free_resource(res); |
| return; |
| } |
| p = &res->sibling; |
| } |
| |
| write_unlock(&resource_lock); |
| |
| printk(KERN_WARNING "Trying to free nonexistent resource " |
| "<%016llx-%016llx>\n", (unsigned long long)start, |
| (unsigned long long)end); |
| } |
| EXPORT_SYMBOL(__release_region); |
| |
| #ifdef CONFIG_MEMORY_HOTREMOVE |
| /** |
| * release_mem_region_adjustable - release a previously reserved memory region |
| * @parent: parent resource descriptor |
| * @start: resource start address |
| * @size: resource region size |
| * |
| * This interface is intended for memory hot-delete. The requested region |
| * is released from a currently busy memory resource. The requested region |
| * must either match exactly or fit into a single busy resource entry. In |
| * the latter case, the remaining resource is adjusted accordingly. |
| * Existing children of the busy memory resource must be immutable in the |
| * request. |
| * |
| * Note: |
| * - Additional release conditions, such as overlapping region, can be |
| * supported after they are confirmed as valid cases. |
| * - When a busy memory resource gets split into two entries, the code |
| * assumes that all children remain in the lower address entry for |
| * simplicity. Enhance this logic when necessary. |
| */ |
| int release_mem_region_adjustable(struct resource *parent, |
| resource_size_t start, resource_size_t size) |
| { |
| struct resource **p; |
| struct resource *res; |
| struct resource *new_res; |
| resource_size_t end; |
| int ret = -EINVAL; |
| |
| end = start + size - 1; |
| if ((start < parent->start) || (end > parent->end)) |
| return ret; |
| |
| /* The alloc_resource() result gets checked later */ |
| new_res = alloc_resource(GFP_KERNEL); |
| |
| p = &parent->child; |
| write_lock(&resource_lock); |
| |
| while ((res = *p)) { |
| if (res->start >= end) |
| break; |
| |
| /* look for the next resource if it does not fit into */ |
| if (res->start > start || res->end < end) { |
| p = &res->sibling; |
| continue; |
| } |
| |
| if (!(res->flags & IORESOURCE_MEM)) |
| break; |
| |
| if (!(res->flags & IORESOURCE_BUSY)) { |
| p = &res->child; |
| continue; |
| } |
| |
| /* found the target resource; let's adjust accordingly */ |
| if (res->start == start && res->end == end) { |
| /* free the whole entry */ |
| *p = res->sibling; |
| free_resource(res); |
| ret = 0; |
| } else if (res->start == start && res->end != end) { |
| /* adjust the start */ |
| ret = __adjust_resource(res, end + 1, |
| res->end - end); |
| } else if (res->start != start && res->end == end) { |
| /* adjust the end */ |
| ret = __adjust_resource(res, res->start, |
| start - res->start); |
| } else { |
| /* split into two entries */ |
| if (!new_res) { |
| ret = -ENOMEM; |
| break; |
| } |
| new_res->name = res->name; |
| new_res->start = end + 1; |
| new_res->end = res->end; |
| new_res->flags = res->flags; |
| new_res->desc = res->desc; |
| new_res->parent = res->parent; |
| new_res->sibling = res->sibling; |
| new_res->child = NULL; |
| |
| ret = __adjust_resource(res, res->start, |
| start - res->start); |
| if (ret) |
| break; |
| res->sibling = new_res; |
| new_res = NULL; |
| } |
| |
| break; |
| } |
| |
| write_unlock(&resource_lock); |
| free_resource(new_res); |
| return ret; |
| } |
| #endif /* CONFIG_MEMORY_HOTREMOVE */ |
| |
| /* |
| * Managed region resource |
| */ |
| static void devm_resource_release(struct device *dev, void *ptr) |
| { |
| struct resource **r = ptr; |
| |
| release_resource(*r); |
| } |
| |
| /** |
| * devm_request_resource() - request and reserve an I/O or memory resource |
| * @dev: device for which to request the resource |
| * @root: root of the resource tree from which to request the resource |
| * @new: descriptor of the resource to request |
| * |
| * This is a device-managed version of request_resource(). There is usually |
| * no need to release resources requested by this function explicitly since |
| * that will be taken care of when the device is unbound from its driver. |
| * If for some reason the resource needs to be released explicitly, because |
| * of ordering issues for example, drivers must call devm_release_resource() |
| * rather than the regular release_resource(). |
| * |
| * When a conflict is detected between any existing resources and the newly |
| * requested resource, an error message will be printed. |
| * |
| * Returns 0 on success or a negative error code on failure. |
| */ |
| int devm_request_resource(struct device *dev, struct resource *root, |
| struct resource *new) |
| { |
| struct resource *conflict, **ptr; |
| |
| ptr = devres_alloc(devm_resource_release, sizeof(*ptr), GFP_KERNEL); |
| if (!ptr) |
| return -ENOMEM; |
| |
| *ptr = new; |
| |
| conflict = request_resource_conflict(root, new); |
| if (conflict) { |
| dev_err(dev, "resource collision: %pR conflicts with %s %pR\n", |
| new, conflict->name, conflict); |
| devres_free(ptr); |
| return -EBUSY; |
| } |
| |
| devres_add(dev, ptr); |
| return 0; |
| } |
| EXPORT_SYMBOL(devm_request_resource); |
| |
| static int devm_resource_match(struct device *dev, void *res, void *data) |
| { |
| struct resource **ptr = res; |
| |
| return *ptr == data; |
| } |
| |
| /** |
| * devm_release_resource() - release a previously requested resource |
| * @dev: device for which to release the resource |
| * @new: descriptor of the resource to release |
| * |
| * Releases a resource previously requested using devm_request_resource(). |
| */ |
| void devm_release_resource(struct device *dev, struct resource *new) |
| { |
| WARN_ON(devres_release(dev, devm_resource_release, devm_resource_match, |
| new)); |
| } |
| EXPORT_SYMBOL(devm_release_resource); |
| |
| struct region_devres { |
| struct resource *parent; |
| resource_size_t start; |
| resource_size_t n; |
| }; |
| |
| static void devm_region_release(struct device *dev, void *res) |
| { |
| struct region_devres *this = res; |
| |
| __release_region(this->parent, this->start, this->n); |
| } |
| |
| static int devm_region_match(struct device *dev, void *res, void *match_data) |
| { |
| struct region_devres *this = res, *match = match_data; |
| |
| return this->parent == match->parent && |
| this->start == match->start && this->n == match->n; |
| } |
| |
| struct resource * __devm_request_region(struct device *dev, |
| struct resource *parent, resource_size_t start, |
| resource_size_t n, const char *name) |
| { |
| struct region_devres *dr = NULL; |
| struct resource *res; |
| |
| dr = devres_alloc(devm_region_release, sizeof(struct region_devres), |
| GFP_KERNEL); |
| if (!dr) |
| return NULL; |
| |
| dr->parent = parent; |
| dr->start = start; |
| dr->n = n; |
| |
| res = __request_region(parent, start, n, name, 0); |
| if (res) |
| devres_add(dev, dr); |
| else |
| devres_free(dr); |
| |
| return res; |
| } |
| EXPORT_SYMBOL(__devm_request_region); |
| |
| void __devm_release_region(struct device *dev, struct resource *parent, |
| resource_size_t start, resource_size_t n) |
| { |
| struct region_devres match_data = { parent, start, n }; |
| |
| __release_region(parent, start, n); |
| WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match, |
| &match_data)); |
| } |
| EXPORT_SYMBOL(__devm_release_region); |
| |
| /* |
| * Called from init/main.c to reserve IO ports. |
| */ |
| #define MAXRESERVE 4 |
| static int __init reserve_setup(char *str) |
| { |
| static int reserved; |
| static struct resource reserve[MAXRESERVE]; |
| |
| for (;;) { |
| unsigned int io_start, io_num; |
| int x = reserved; |
| |
| if (get_option (&str, &io_start) != 2) |
| break; |
| if (get_option (&str, &io_num) == 0) |
| break; |
| if (x < MAXRESERVE) { |
| struct resource *res = reserve + x; |
| res->name = "reserved"; |
| res->start = io_start; |
| res->end = io_start + io_num - 1; |
| res->flags = IORESOURCE_BUSY; |
| res->desc = IORES_DESC_NONE; |
| res->child = NULL; |
| if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0) |
| reserved = x+1; |
| } |
| } |
| return 1; |
| } |
| |
| __setup("reserve=", reserve_setup); |
| |
| /* |
| * Check if the requested addr and size spans more than any slot in the |
| * iomem resource tree. |
| */ |
| int iomem_map_sanity_check(resource_size_t addr, unsigned long size) |
| { |
| struct resource *p = &iomem_resource; |
| int err = 0; |
| loff_t l; |
| |
| read_lock(&resource_lock); |
| for (p = p->child; p ; p = r_next(NULL, p, &l)) { |
| /* |
| * We can probably skip the resources without |
| * IORESOURCE_IO attribute? |
| */ |
| if (p->start >= addr + size) |
| continue; |
| if (p->end < addr) |
| continue; |
| if (PFN_DOWN(p->start) <= PFN_DOWN(addr) && |
| PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1)) |
| continue; |
| /* |
| * if a resource is "BUSY", it's not a hardware resource |
| * but a driver mapping of such a resource; we don't want |
| * to warn for those; some drivers legitimately map only |
| * partial hardware resources. (example: vesafb) |
| */ |
| if (p->flags & IORESOURCE_BUSY) |
| continue; |
| |
| printk(KERN_WARNING "resource sanity check: requesting [mem %#010llx-%#010llx], which spans more than %s %pR\n", |
| (unsigned long long)addr, |
| (unsigned long long)(addr + size - 1), |
| p->name, p); |
| err = -1; |
| break; |
| } |
| read_unlock(&resource_lock); |
| |
| return err; |
| } |
| |
| #ifdef CONFIG_STRICT_DEVMEM |
| static int strict_iomem_checks = 1; |
| #else |
| static int strict_iomem_checks; |
| #endif |
| |
| /* |
| * check if an address is reserved in the iomem resource tree |
| * returns 1 if reserved, 0 if not reserved. |
| */ |
| int iomem_is_exclusive(u64 addr) |
| { |
| struct resource *p = &iomem_resource; |
| int err = 0; |
| loff_t l; |
| int size = PAGE_SIZE; |
| |
| if (!strict_iomem_checks) |
| return 0; |
| |
| addr = addr & PAGE_MASK; |
| |
| read_lock(&resource_lock); |
| for (p = p->child; p ; p = r_next(NULL, p, &l)) { |
| /* |
| * We can probably skip the resources without |
| * IORESOURCE_IO attribute? |
| */ |
| if (p->start >= addr + size) |
| break; |
| if (p->end < addr) |
| continue; |
| /* |
| * A resource is exclusive if IORESOURCE_EXCLUSIVE is set |
| * or CONFIG_IO_STRICT_DEVMEM is enabled and the |
| * resource is busy. |
| */ |
| if ((p->flags & IORESOURCE_BUSY) == 0) |
| continue; |
| if (IS_ENABLED(CONFIG_IO_STRICT_DEVMEM) |
| || p->flags & IORESOURCE_EXCLUSIVE) { |
| err = 1; |
| break; |
| } |
| } |
| read_unlock(&resource_lock); |
| |
| return err; |
| } |
| |
| struct resource_entry *resource_list_create_entry(struct resource *res, |
| size_t extra_size) |
| { |
| struct resource_entry *entry; |
| |
| entry = kzalloc(sizeof(*entry) + extra_size, GFP_KERNEL); |
| if (entry) { |
| INIT_LIST_HEAD(&entry->node); |
| entry->res = res ? res : &entry->__res; |
| } |
| |
| return entry; |
| } |
| EXPORT_SYMBOL(resource_list_create_entry); |
| |
| void resource_list_free(struct list_head *head) |
| { |
| struct resource_entry *entry, *tmp; |
| |
| list_for_each_entry_safe(entry, tmp, head, node) |
| resource_list_destroy_entry(entry); |
| } |
| EXPORT_SYMBOL(resource_list_free); |
| |
| static int __init strict_iomem(char *str) |
| { |
| if (strstr(str, "relaxed")) |
| strict_iomem_checks = 0; |
| if (strstr(str, "strict")) |
| strict_iomem_checks = 1; |
| return 1; |
| } |
| |
| __setup("iomem=", strict_iomem); |