diff options
Diffstat (limited to 'kernel/resource.c')
| -rw-r--r-- | kernel/resource.c | 2017 |
1 files changed, 2017 insertions, 0 deletions
diff --git a/kernel/resource.c b/kernel/resource.c new file mode 100644 index 0000000000..e3f5680a56 --- /dev/null +++ b/kernel/resource.c @@ -0,0 +1,2017 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * 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/pseudo_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/mount.h> +#include <linux/resource_ext.h> +#include <uapi/linux/magic.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); + +static struct resource *next_resource(struct resource *p) +{ + if (p->child) + return p->child; + while (!p->sibling && p->parent) + p = p->parent; + return p->sibling; +} + +static struct resource *next_resource_skip_children(struct resource *p) +{ + while (!p->sibling && p->parent) + p = p->parent; + return p->sibling; +} + +#define for_each_resource(_root, _p, _skip_children) \ + for ((_p) = (_root)->child; (_p); \ + (_p) = (_skip_children) ? next_resource_skip_children(_p) : \ + next_resource(_p)) + +static void *r_next(struct seq_file *m, void *v, loff_t *pos) +{ + struct resource *p = v; + (*pos)++; + return (void *)next_resource(p); +} + +#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 = pde_data(file_inode(m->file)); + 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 = pde_data(file_inode(m->file)); + struct resource *r = v, *p; + unsigned long long start, end; + 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; + + if (file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN)) { + start = r->start; + end = r->end; + } else { + start = end = 0; + } + + seq_printf(m, "%*s%0*llx-%0*llx : %s\n", + depth * 2, "", + width, start, + width, 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 __init ioresources_init(void) +{ + proc_create_seq_data("ioports", 0, NULL, &resource_op, + &ioport_resource); + proc_create_seq_data("iomem", 0, NULL, &resource_op, &iomem_resource); + return 0; +} +__initcall(ioresources_init); + +#endif /* CONFIG_PROC_FS */ + +static void free_resource(struct resource *res) +{ + /** + * If the resource was allocated using memblock early during boot + * we'll leak it here: we can only return full pages back to the + * buddy and trying to be smart and reusing them eventually in + * alloc_resource() overcomplicates resource handling. + */ + if (res && PageSlab(virt_to_head_page(res))) + kfree(res); +} + +static struct resource *alloc_resource(gfp_t flags) +{ + return kzalloc(sizeof(struct resource), flags); +} + +/* 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, bool release_child) +{ + struct resource *tmp, **p, *chd; + + p = &old->parent->child; + for (;;) { + tmp = *p; + if (!tmp) + break; + if (tmp == old) { + if (release_child || !(tmp->child)) { + *p = tmp->sibling; + } else { + for (chd = tmp->child;; chd = chd->sibling) { + chd->parent = tmp->parent; + if (!(chd->sibling)) + break; + } + *p = tmp->child; + chd->sibling = 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, true); + write_unlock(&resource_lock); + return retval; +} + +EXPORT_SYMBOL(release_resource); + +/** + * find_next_iomem_res - Finds the lowest iomem resource that covers part of + * [@start..@end]. + * + * If a resource is found, returns 0 and @*res is overwritten with the part + * of the resource that's within [@start..@end]; if none is found, returns + * -ENODEV. Returns -EINVAL for invalid parameters. + * + * @start: start address of the resource searched for + * @end: end address of same resource + * @flags: flags which the resource must have + * @desc: descriptor the resource must have + * @res: return ptr, if resource found + * + * The caller must specify @start, @end, @flags, and @desc + * (which may be IORES_DESC_NONE). + */ +static int find_next_iomem_res(resource_size_t start, resource_size_t end, + unsigned long flags, unsigned long desc, + struct resource *res) +{ + struct resource *p; + + if (!res) + return -EINVAL; + + if (start >= end) + return -EINVAL; + + read_lock(&resource_lock); + + for (p = iomem_resource.child; p; p = next_resource(p)) { + /* If we passed the resource we are looking for, stop */ + if (p->start > end) { + p = NULL; + break; + } + + /* Skip until we find a range that matches what we look for */ + if (p->end < start) + continue; + + if ((p->flags & flags) != flags) + continue; + if ((desc != IORES_DESC_NONE) && (desc != p->desc)) + continue; + + /* Found a match, break */ + break; + } + + if (p) { + /* copy data */ + *res = (struct resource) { + .start = max(start, p->start), + .end = min(end, p->end), + .flags = p->flags, + .desc = p->desc, + .parent = p->parent, + }; + } + + read_unlock(&resource_lock); + return p ? 0 : -ENODEV; +} + +static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end, + unsigned long flags, unsigned long desc, + void *arg, + int (*func)(struct resource *, void *)) +{ + struct resource res; + int ret = -EINVAL; + + while (start < end && + !find_next_iomem_res(start, end, flags, desc, &res)) { + ret = (*func)(&res, arg); + if (ret) + break; + + start = res.end + 1; + } + + return ret; +} + +/** + * walk_iomem_res_desc - Walks through iomem resources and calls func() + * with matching resource ranges. + * * + * @desc: I/O resource descriptor. Use IORES_DESC_NONE to skip @desc check. + * @flags: I/O resource flags + * @start: start addr + * @end: end addr + * @arg: function argument for the callback @func + * @func: callback function that is called for each qualifying resource area + * + * All the memory ranges which overlap start,end and also match flags and + * desc are valid candidates. + * + * 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)(struct resource *, void *)) +{ + return __walk_iomem_res_desc(start, end, flags, desc, arg, func); +} +EXPORT_SYMBOL_GPL(walk_iomem_res_desc); + +/* + * 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)(struct resource *, void *)) +{ + unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; + + return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, arg, + func); +} + +/* + * This function calls the @func callback against all memory ranges, which + * are ranges marked as IORESOURCE_MEM and IORESOUCE_BUSY. + */ +int walk_mem_res(u64 start, u64 end, void *arg, + int (*func)(struct resource *, void *)) +{ + unsigned long flags = IORESOURCE_MEM | IORESOURCE_BUSY; + + return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, arg, + func); +} + +/* + * 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 *)) +{ + resource_size_t start, end; + unsigned long flags; + struct resource res; + unsigned long pfn, end_pfn; + int ret = -EINVAL; + + start = (u64) start_pfn << PAGE_SHIFT; + end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1; + flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; + while (start < end && + !find_next_iomem_res(start, end, flags, IORES_DESC_NONE, &res)) { + pfn = PFN_UP(res.start); + end_pfn = PFN_DOWN(res.end + 1); + if (end_pfn > pfn) + ret = (*func)(pfn, end_pfn - pfn, arg); + if (ret) + break; + start = res.end + 1; + } + return ret; +} + +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); + +static int __region_intersects(struct resource *parent, resource_size_t start, + size_t size, unsigned long flags, + unsigned long desc) +{ + struct resource res; + int type = 0; int other = 0; + struct resource *p; + + res.start = start; + res.end = start + size - 1; + + for (p = parent->child; p ; p = p->sibling) { + bool is_type = (((p->flags & flags) == flags) && + ((desc == IORES_DESC_NONE) || + (desc == p->desc))); + + if (resource_overlaps(p, &res)) + is_type ? type++ : other++; + } + + if (type == 0) + return REGION_DISJOINT; + + if (other == 0) + return REGION_INTERSECTS; + + return REGION_MIXED; +} + +/** + * 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) +{ + int ret; + + read_lock(&resource_lock); + ret = __region_intersects(&iomem_resource, start, size, flags, desc); + read_unlock(&resource_lock); + + return ret; +} +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 (alloc.start <= alloc.end && + 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, true); + *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. + * + * This function is intended for producers of resources, such as FW modules + * and bus drivers. + */ +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. + * + * This function is intended for producers of resources, such as FW modules + * and bus drivers. + */ +int insert_resource(struct resource *parent, struct resource *new) +{ + struct resource *conflict; + + conflict = insert_resource_conflict(parent, new); + return conflict ? -EBUSY : 0; +} +EXPORT_SYMBOL_GPL(insert_resource); + +/** + * 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; + + pr_info("Expanded resource %s due to conflict with %s\n", new->name, conflict->name); + } + write_unlock(&resource_lock); +} +/* + * Not for general consumption, only early boot memory map parsing, PCI + * resource discovery, and late discovery of CXL resources are expected + * to use this interface. The former are built-in and only the latter, + * CXL, is a module. + */ +EXPORT_SYMBOL_NS_GPL(insert_resource_expand_to_fit, CXL); + +/** + * remove_resource - Remove a resource in the resource tree + * @old: resource to remove + * + * Returns 0 on success, -EINVAL if the resource is not valid. + * + * This function removes a resource previously inserted by insert_resource() + * or insert_resource_conflict(), and moves the children (if any) up to + * where they were before. insert_resource() and insert_resource_conflict() + * insert a new resource, and move any conflicting resources down to the + * children of the new resource. + * + * insert_resource(), insert_resource_conflict() and remove_resource() are + * intended for producers of resources, such as FW modules and bus drivers. + */ +int remove_resource(struct resource *old) +{ + int retval; + + write_lock(&resource_lock); + retval = __release_resource(old, false); + write_unlock(&resource_lock); + return retval; +} +EXPORT_SYMBOL_GPL(remove_resource); + +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; + int type = resource_type(root); + + if (!res) + return; + + res->name = name; + res->start = start; + res->end = end; + res->flags = type | 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 = type | 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); + +static struct inode *iomem_inode; + +#ifdef CONFIG_IO_STRICT_DEVMEM +static void revoke_iomem(struct resource *res) +{ + /* pairs with smp_store_release() in iomem_init_inode() */ + struct inode *inode = smp_load_acquire(&iomem_inode); + + /* + * Check that the initialization has completed. Losing the race + * is ok because it means drivers are claiming resources before + * the fs_initcall level of init and prevent iomem_get_mapping users + * from establishing mappings. + */ + if (!inode) + return; + + /* + * The expectation is that the driver has successfully marked + * the resource busy by this point, so devmem_is_allowed() + * should start returning false, however for performance this + * does not iterate the entire resource range. + */ + if (devmem_is_allowed(PHYS_PFN(res->start)) && + devmem_is_allowed(PHYS_PFN(res->end))) { + /* + * *cringe* iomem=relaxed says "go ahead, what's the + * worst that can happen?" + */ + return; + } + + unmap_mapping_range(inode->i_mapping, res->start, resource_size(res), 1); +} +#else +static void revoke_iomem(struct resource *res) {} +#endif + +struct address_space *iomem_get_mapping(void) +{ + /* + * This function is only called from file open paths, hence guaranteed + * that fs_initcalls have completed and no need to check for NULL. But + * since revoke_iomem can be called before the initcall we still need + * the barrier to appease checkers. + */ + return smp_load_acquire(&iomem_inode)->i_mapping; +} + +static int __request_region_locked(struct resource *res, struct resource *parent, + resource_size_t start, resource_size_t n, + const char *name, int flags) +{ + DECLARE_WAITQUEUE(wait, current); + + res->name = name; + res->start = start; + res->end = start + n - 1; + + for (;;) { + struct resource *conflict; + + res->flags = resource_type(parent) | resource_ext_type(parent); + res->flags |= IORESOURCE_BUSY | flags; + res->desc = parent->desc; + + conflict = __request_resource(parent, res); + if (!conflict) + break; + /* + * mm/hmm.c reserves physical addresses which then + * become unavailable to other users. Conflicts are + * not expected. Warn to aid debugging if encountered. + */ + if (conflict->desc == IORES_DESC_DEVICE_PRIVATE_MEMORY) { + pr_warn("Unaddressable device %s %pR conflicts with %pR", + conflict->name, conflict, res); + } + 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.. */ + return -EBUSY; + } + + return 0; +} + +/** + * __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) +{ + struct resource *res = alloc_resource(GFP_KERNEL); + int ret; + + if (!res) + return NULL; + + write_lock(&resource_lock); + ret = __request_region_locked(res, parent, start, n, name, flags); + write_unlock(&resource_lock); + + if (ret) { + free_resource(res); + return NULL; + } + + if (parent == &iomem_resource) + revoke_iomem(res); + + 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); + + pr_warn("Trying to free nonexistent resource <%pa-%pa>\n", &start, &end); +} +EXPORT_SYMBOL(__release_region); + +#ifdef CONFIG_MEMORY_HOTREMOVE +/** + * release_mem_region_adjustable - release a previously reserved memory region + * @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. + */ +void release_mem_region_adjustable(resource_size_t start, resource_size_t size) +{ + struct resource *parent = &iomem_resource; + struct resource *new_res = NULL; + bool alloc_nofail = false; + struct resource **p; + struct resource *res; + resource_size_t end; + + end = start + size - 1; + if (WARN_ON_ONCE((start < parent->start) || (end > parent->end))) + return; + + /* + * We free up quite a lot of memory on memory hotunplug (esp., memap), + * just before releasing the region. This is highly unlikely to + * fail - let's play save and make it never fail as the caller cannot + * perform any error handling (e.g., trying to re-add memory will fail + * similarly). + */ +retry: + new_res = alloc_resource(GFP_KERNEL | (alloc_nofail ? __GFP_NOFAIL : 0)); + + 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); + } else if (res->start == start && res->end != end) { + /* adjust the start */ + WARN_ON_ONCE(__adjust_resource(res, end + 1, + res->end - end)); + } else if (res->start != start && res->end == end) { + /* adjust the end */ + WARN_ON_ONCE(__adjust_resource(res, res->start, + start - res->start)); + } else { + /* split into two entries - we need a new resource */ + if (!new_res) { + new_res = alloc_resource(GFP_ATOMIC); + if (!new_res) { + alloc_nofail = true; + write_unlock(&resource_lock); + goto retry; + } + } + 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; + + if (WARN_ON_ONCE(__adjust_resource(res, res->start, + start - res->start))) + break; + res->sibling = new_res; + new_res = NULL; + } + + break; + } + + write_unlock(&resource_lock); + free_resource(new_res); +} +#endif /* CONFIG_MEMORY_HOTREMOVE */ + +#ifdef CONFIG_MEMORY_HOTPLUG +static bool system_ram_resources_mergeable(struct resource *r1, + struct resource *r2) +{ + /* We assume either r1 or r2 is IORESOURCE_SYSRAM_MERGEABLE. */ + return r1->flags == r2->flags && r1->end + 1 == r2->start && + r1->name == r2->name && r1->desc == r2->desc && + !r1->child && !r2->child; +} + +/** + * merge_system_ram_resource - mark the System RAM resource mergeable and try to + * merge it with adjacent, mergeable resources + * @res: resource descriptor + * + * This interface is intended for memory hotplug, whereby lots of contiguous + * system ram resources are added (e.g., via add_memory*()) by a driver, and + * the actual resource boundaries are not of interest (e.g., it might be + * relevant for DIMMs). Only resources that are marked mergeable, that have the + * same parent, and that don't have any children are considered. All mergeable + * resources must be immutable during the request. + * + * Note: + * - The caller has to make sure that no pointers to resources that are + * marked mergeable are used anymore after this call - the resource might + * be freed and the pointer might be stale! + * - release_mem_region_adjustable() will split on demand on memory hotunplug + */ +void merge_system_ram_resource(struct resource *res) +{ + const unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; + struct resource *cur; + + if (WARN_ON_ONCE((res->flags & flags) != flags)) + return; + + write_lock(&resource_lock); + res->flags |= IORESOURCE_SYSRAM_MERGEABLE; + + /* Try to merge with next item in the list. */ + cur = res->sibling; + if (cur && system_ram_resources_mergeable(res, cur)) { + res->end = cur->end; + res->sibling = cur->sibling; + free_resource(cur); + } + + /* Try to merge with previous item in the list. */ + cur = res->parent->child; + while (cur && cur->sibling != res) + cur = cur->sibling; + if (cur && system_ram_resources_mergeable(cur, res)) { + cur->end = res->end; + cur->sibling = res->sibling; + free_resource(res); + } + write_unlock(&resource_lock); +} +#endif /* CONFIG_MEMORY_HOTPLUG */ + +/* + * 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); + +/* + * Reserve I/O ports or memory based on "reserve=" kernel parameter. + */ +#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; + struct resource *parent; + + if (get_option(&str, &io_start) != 2) + break; + if (get_option(&str, &io_num) == 0) + break; + if (x < MAXRESERVE) { + struct resource *res = reserve + x; + + /* + * If the region starts below 0x10000, we assume it's + * I/O port space; otherwise assume it's memory. + */ + if (io_start < 0x10000) { + res->flags = IORESOURCE_IO; + parent = &ioport_resource; + } else { + res->flags = IORESOURCE_MEM; + parent = &iomem_resource; + } + 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(parent, 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; + resource_size_t end = addr + size - 1; + 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 > end) + continue; + if (p->end < addr) + continue; + if (PFN_DOWN(p->start) <= PFN_DOWN(addr) && + PFN_DOWN(p->end) >= PFN_DOWN(end)) + 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; + + pr_warn("resource sanity check: requesting [mem %pa-%pa], which spans more than %s %pR\n", + &addr, &end, 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 exclusive to the kernel and must not be mapped to + * user space, for example, via /dev/mem. + * + * Returns true if exclusive to the kernel, otherwise returns false. + */ +bool resource_is_exclusive(struct resource *root, u64 addr, resource_size_t size) +{ + const unsigned int exclusive_system_ram = IORESOURCE_SYSTEM_RAM | + IORESOURCE_EXCLUSIVE; + bool skip_children = false, err = false; + struct resource *p; + + read_lock(&resource_lock); + for_each_resource(root, p, skip_children) { + if (p->start >= addr + size) + break; + if (p->end < addr) { + skip_children = true; + continue; + } + skip_children = false; + + /* + * IORESOURCE_SYSTEM_RAM resources are exclusive if + * IORESOURCE_EXCLUSIVE is set, even if they + * are not busy and even if "iomem=relaxed" is set. The + * responsible driver dynamically adds/removes system RAM within + * such an area and uncontrolled access is dangerous. + */ + if ((p->flags & exclusive_system_ram) == exclusive_system_ram) { + err = true; + break; + } + + /* + * A resource is exclusive if IORESOURCE_EXCLUSIVE is set + * or CONFIG_IO_STRICT_DEVMEM is enabled and the + * resource is busy. + */ + if (!strict_iomem_checks || !(p->flags & IORESOURCE_BUSY)) + continue; + if (IS_ENABLED(CONFIG_IO_STRICT_DEVMEM) + || p->flags & IORESOURCE_EXCLUSIVE) { + err = true; + break; + } + } + read_unlock(&resource_lock); + + return err; +} + +bool iomem_is_exclusive(u64 addr) +{ + return resource_is_exclusive(&iomem_resource, addr & PAGE_MASK, + PAGE_SIZE); +} + +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); + +#ifdef CONFIG_GET_FREE_REGION +#define GFR_DESCENDING (1UL << 0) +#define GFR_REQUEST_REGION (1UL << 1) +#define GFR_DEFAULT_ALIGN (1UL << PA_SECTION_SHIFT) + +static resource_size_t gfr_start(struct resource *base, resource_size_t size, + resource_size_t align, unsigned long flags) +{ + if (flags & GFR_DESCENDING) { + resource_size_t end; + + end = min_t(resource_size_t, base->end, + (1ULL << MAX_PHYSMEM_BITS) - 1); + return end - size + 1; + } + + return ALIGN(base->start, align); +} + +static bool gfr_continue(struct resource *base, resource_size_t addr, + resource_size_t size, unsigned long flags) +{ + if (flags & GFR_DESCENDING) + return addr > size && addr >= base->start; + /* + * In the ascend case be careful that the last increment by + * @size did not wrap 0. + */ + return addr > addr - size && + addr <= min_t(resource_size_t, base->end, + (1ULL << MAX_PHYSMEM_BITS) - 1); +} + +static resource_size_t gfr_next(resource_size_t addr, resource_size_t size, + unsigned long flags) +{ + if (flags & GFR_DESCENDING) + return addr - size; + return addr + size; +} + +static void remove_free_mem_region(void *_res) +{ + struct resource *res = _res; + + if (res->parent) + remove_resource(res); + free_resource(res); +} + +static struct resource * +get_free_mem_region(struct device *dev, struct resource *base, + resource_size_t size, const unsigned long align, + const char *name, const unsigned long desc, + const unsigned long flags) +{ + resource_size_t addr; + struct resource *res; + struct region_devres *dr = NULL; + + size = ALIGN(size, align); + + res = alloc_resource(GFP_KERNEL); + if (!res) + return ERR_PTR(-ENOMEM); + + if (dev && (flags & GFR_REQUEST_REGION)) { + dr = devres_alloc(devm_region_release, + sizeof(struct region_devres), GFP_KERNEL); + if (!dr) { + free_resource(res); + return ERR_PTR(-ENOMEM); + } + } else if (dev) { + if (devm_add_action_or_reset(dev, remove_free_mem_region, res)) + return ERR_PTR(-ENOMEM); + } + + write_lock(&resource_lock); + for (addr = gfr_start(base, size, align, flags); + gfr_continue(base, addr, align, flags); + addr = gfr_next(addr, align, flags)) { + if (__region_intersects(base, addr, size, 0, IORES_DESC_NONE) != + REGION_DISJOINT) + continue; + + if (flags & GFR_REQUEST_REGION) { + if (__request_region_locked(res, &iomem_resource, addr, + size, name, 0)) + break; + + if (dev) { + dr->parent = &iomem_resource; + dr->start = addr; + dr->n = size; + devres_add(dev, dr); + } + + res->desc = desc; + write_unlock(&resource_lock); + + + /* + * A driver is claiming this region so revoke any + * mappings. + */ + revoke_iomem(res); + } else { + res->start = addr; + res->end = addr + size - 1; + res->name = name; + res->desc = desc; + res->flags = IORESOURCE_MEM; + + /* + * Only succeed if the resource hosts an exclusive + * range after the insert + */ + if (__insert_resource(base, res) || res->child) + break; + + write_unlock(&resource_lock); + } + + return res; + } + write_unlock(&resource_lock); + + if (flags & GFR_REQUEST_REGION) { + free_resource(res); + devres_free(dr); + } else if (dev) + devm_release_action(dev, remove_free_mem_region, res); + + return ERR_PTR(-ERANGE); +} + +/** + * devm_request_free_mem_region - find free region for device private memory + * + * @dev: device struct to bind the resource to + * @size: size in bytes of the device memory to add + * @base: resource tree to look in + * + * This function tries to find an empty range of physical address big enough to + * contain the new resource, so that it can later be hotplugged as ZONE_DEVICE + * memory, which in turn allocates struct pages. + */ +struct resource *devm_request_free_mem_region(struct device *dev, + struct resource *base, unsigned long size) +{ + unsigned long flags = GFR_DESCENDING | GFR_REQUEST_REGION; + + return get_free_mem_region(dev, base, size, GFR_DEFAULT_ALIGN, + dev_name(dev), + IORES_DESC_DEVICE_PRIVATE_MEMORY, flags); +} +EXPORT_SYMBOL_GPL(devm_request_free_mem_region); + +struct resource *request_free_mem_region(struct resource *base, + unsigned long size, const char *name) +{ + unsigned long flags = GFR_DESCENDING | GFR_REQUEST_REGION; + + return get_free_mem_region(NULL, base, size, GFR_DEFAULT_ALIGN, name, + IORES_DESC_DEVICE_PRIVATE_MEMORY, flags); +} +EXPORT_SYMBOL_GPL(request_free_mem_region); + +/** + * alloc_free_mem_region - find a free region relative to @base + * @base: resource that will parent the new resource + * @size: size in bytes of memory to allocate from @base + * @align: alignment requirements for the allocation + * @name: resource name + * + * Buses like CXL, that can dynamically instantiate new memory regions, + * need a method to allocate physical address space for those regions. + * Allocate and insert a new resource to cover a free, unclaimed by a + * descendant of @base, range in the span of @base. + */ +struct resource *alloc_free_mem_region(struct resource *base, + unsigned long size, unsigned long align, + const char *name) +{ + /* Default of ascending direction and insert resource */ + unsigned long flags = 0; + + return get_free_mem_region(NULL, base, size, align, name, + IORES_DESC_NONE, flags); +} +EXPORT_SYMBOL_NS_GPL(alloc_free_mem_region, CXL); +#endif /* CONFIG_GET_FREE_REGION */ + +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; +} + +static int iomem_fs_init_fs_context(struct fs_context *fc) +{ + return init_pseudo(fc, DEVMEM_MAGIC) ? 0 : -ENOMEM; +} + +static struct file_system_type iomem_fs_type = { + .name = "iomem", + .owner = THIS_MODULE, + .init_fs_context = iomem_fs_init_fs_context, + .kill_sb = kill_anon_super, +}; + +static int __init iomem_init_inode(void) +{ + static struct vfsmount *iomem_vfs_mount; + static int iomem_fs_cnt; + struct inode *inode; + int rc; + + rc = simple_pin_fs(&iomem_fs_type, &iomem_vfs_mount, &iomem_fs_cnt); + if (rc < 0) { + pr_err("Cannot mount iomem pseudo filesystem: %d\n", rc); + return rc; + } + + inode = alloc_anon_inode(iomem_vfs_mount->mnt_sb); + if (IS_ERR(inode)) { + rc = PTR_ERR(inode); + pr_err("Cannot allocate inode for iomem: %d\n", rc); + simple_release_fs(&iomem_vfs_mount, &iomem_fs_cnt); + return rc; + } + + /* + * Publish iomem revocation inode initialized. + * Pairs with smp_load_acquire() in revoke_iomem(). + */ + smp_store_release(&iomem_inode, inode); + + return 0; +} + +fs_initcall(iomem_init_inode); + +__setup("iomem=", strict_iomem); |