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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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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 <linux/string.h>#include <linux/vmalloc.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);
struct resource soft_reserve_resource = { .name = "Soft Reserved", .start = 0, .end = -1, .desc = IORES_DESC_SOFT_RESERVED, .flags = IORESOURCE_MEM,};
static DEFINE_RWLOCK(resource_lock);
/* * Return the next node of @p in pre-order tree traversal. If * @skip_children is true, skip the descendant nodes of @p in * traversal. If @p is a descendant of @subtree_root, only traverse * the subtree under @subtree_root. */static struct resource *next_resource(struct resource *p, bool skip_children, struct resource *subtree_root){ if (!skip_children && p->child) return p->child; while (!p->sibling && p->parent) { p = p->parent; if (p == subtree_root) return NULL; } return p->sibling;}
/* * Traverse the resource subtree under @_root in pre-order, excluding * @_root itself. * * NOTE: '__p' is introduced to avoid shadowing '_p' outside of loop. * And it is referenced to avoid unused variable warning. */#define for_each_resource(_root, _p, _skip_children) \ for (typeof(_root) __root = (_root), __p = _p = __root->child; \ __p && _p; _p = next_resource(_p, _skip_children, __root))
#ifdef CONFIG_PROC_FS
enum { MAX_IORES_LEVEL = 8 };
static void *r_start(struct seq_file *m, loff_t *pos) __acquires(resource_lock){ struct resource *root = pde_data(file_inode(m->file)); struct resource *p; loff_t l = *pos;
read_lock(&resource_lock); for_each_resource(root, p, false) { if (l-- == 0) break; }
return p;}
static void *r_next(struct seq_file *m, void *v, loff_t *pos){ struct resource *p = v;
(*pos)++;
return (void *)next_resource(p, false, NULL);}
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_obj(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);
static bool is_type_match(struct resource *p, unsigned long flags, unsigned long desc){ return (p->flags & flags) == flags && (desc == IORES_DESC_NONE || desc == p->desc);}
/** * find_next_res - Finds the lowest 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. * * @parent: resource tree root to search * @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_res(struct resource *parent, resource_size_t start, resource_size_t end, unsigned long flags, unsigned long desc, struct resource *res){ /* Skip children until we find a top level range that matches */ bool skip_children = true; struct resource *p;
if (!res) return -EINVAL;
if (start >= end) return -EINVAL;
read_lock(&resource_lock);
for_each_resource(parent, p, skip_children) { /* 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;
/* * We found a top level range that matches what we are looking * for. Time to start checking children too. */ skip_children = false;
/* Found a match, break */ if (is_type_match(p, flags, desc)) 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 find_next_iomem_res(resource_size_t start, resource_size_t end, unsigned long flags, unsigned long desc, struct resource *res){ return find_next_res(&iomem_resource, start, end, flags, desc, res);}
static int walk_res_desc(struct resource *parent, 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_res(parent, start, end, flags, desc, &res)) { ret = (*func)(&res, arg); if (ret) break;
start = res.end + 1; }
return ret;}
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 *)){ return walk_res_desc(&iomem_resource, start, end, flags, desc, arg, func);}
/** * 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);
/* * In support of device drivers claiming Soft Reserved resources, walk the Soft * Reserved resource deferral tree. */int walk_soft_reserve_res(u64 start, u64 end, void *arg, int (*func)(struct resource *, void *)){ return walk_res_desc(&soft_reserve_resource, start, end, IORESOURCE_MEM, IORES_DESC_SOFT_RESERVED, arg, func);}EXPORT_SYMBOL_GPL(walk_soft_reserve_res);
/* * 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, being a variant of walk_system_ram_res(), calls the @func * callback against all memory ranges of type System RAM which are marked as * IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY in reversed order, i.e., from * higher to lower. */int walk_system_ram_res_rev(u64 start, u64 end, void *arg, int (*func)(struct resource *, void *)){ struct resource res, *rams; int rams_size = 16, i; unsigned long flags; int ret = -1;
/* create a list */ rams = kvzalloc_objs(struct resource, rams_size); if (!rams) return ret;
flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; i = 0; while ((start < end) && (!find_next_iomem_res(start, end, flags, IORES_DESC_NONE, &res))) { if (i >= rams_size) { /* re-alloc */ struct resource *rams_new;
rams_new = kvrealloc(rams, (rams_size + 16) * sizeof(struct resource), GFP_KERNEL); if (!rams_new) goto out;
rams = rams_new; rams_size += 16; }
rams[i++] = res; start = res.end + 1; }
/* go reverse */ for (i--; i >= 0; i--) { ret = (*func)(&rams[i], arg); if (ret) break; }
out: kvfree(rams); return ret;}
/* * 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){ int type = 0; int other = 0; struct resource *p, *dp; struct resource res, o; bool covered;
res = DEFINE_RES(start, size, 0);
for (p = parent->child; p ; p = p->sibling) { if (!resource_intersection(p, &res, &o)) continue; if (is_type_match(p, flags, desc)) { type++; continue; } /* * Continue to search in descendant resources as if the * matched descendant resources cover some ranges of 'p'. * * |------------- "CXL Window 0" ------------| * |-- "System RAM" --| * * will behave similar as the following fake resource * tree when searching "System RAM". * * |-- "System RAM" --||-- "CXL Window 0a" --| */ covered = false; for_each_resource(p, dp, false) { if (!resource_overlaps(dp, &res)) continue; if (is_type_match(dp, flags, desc)) { type++; /* * Range from 'o.start' to 'dp->start' * isn't covered by matched resource. */ if (dp->start > o.start) break; if (dp->end >= o.end) { covered = true; break; } /* Remove covered range */ o.start = max(o.start, dp->end + 1); } } if (!covered) 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);
/* * Check if the provided range is registered in the Soft Reserved resource * deferral tree for driver consideration. */int region_intersects_soft_reserve(resource_size_t start, size_t size){ guard(read_lock)(&resource_lock); return __region_intersects(&soft_reserve_resource, start, size, IORESOURCE_MEM, IORES_DESC_SOFT_RESERVED);}EXPORT_SYMBOL_GPL(region_intersects_soft_reserve);
void __weak arch_remove_reservations(struct resource *avail){}
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 space in the resource tree with the given range and * alignment constraints */static int __find_resource_space(struct resource *root, struct resource *old, struct resource *new, resource_size_t size, struct resource_constraint *constraint){ struct resource *this = root->child; struct resource full_avail = *new, avail, alloc; resource_alignf alignf = constraint->alignf;
full_avail.start = root->start; /* * Skip past an allocated resource that starts at 0, since the assignment * of this->start - 1 to full_avail->end below would cause an underflow. */ if (this && this->start == root->start) { full_avail.start = (this == old) ? old->start : this->end + 1; this = this->sibling; } for(;;) { if (this) full_avail.end = (this == old) ? this->end : this->start - 1; else full_avail.end = root->end;
if (full_avail.end < full_avail.start) goto next;
resource_clip(&full_avail, constraint->min, constraint->max); arch_remove_reservations(&full_avail);
/* Check for overflow after ALIGN() */ avail.start = ALIGN(full_avail.start, constraint->align); avail.end = full_avail.end; avail.flags = new->flags; if (avail.start >= full_avail.start) { alloc.flags = avail.flags; if (alignf) { alloc.start = alignf(constraint->alignf_data, &avail, &full_avail, size, constraint->align); } else { alloc.start = avail.start; } alloc.end = alloc.start + size - 1; if (alloc.start <= alloc.end && __resource_contains_unbound(&full_avail, &alloc)) { new->start = alloc.start; new->end = alloc.end; return 0; } }
next: if (!this || this->end == root->end) break;
if (this != old) full_avail.start = this->end + 1; this = this->sibling; } return -EBUSY;}
/** * find_resource_space - Find empty space in the resource tree * @root: Root resource descriptor * @new: Resource descriptor awaiting an empty resource space * @size: The minimum size of the empty space * @constraint: The range and alignment constraints to be met * * Finds an empty space under @root in the resource tree satisfying range and * alignment @constraints. * * Return: * * %0 - if successful, @new members start, end, and flags are altered. * * %-EBUSY - if no empty space was found. */int find_resource_space(struct resource *root, struct resource *new, resource_size_t size, struct resource_constraint *constraint){ return __find_resource_space(root, NULL, new, size, constraint);}EXPORT_SYMBOL_GPL(find_resource_space);
/** * 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 memory range 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_space(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_alignf alignf, void *alignf_data){ int err; struct resource_constraint constraint;
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_space(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 __initreserve_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(const 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_DEVMEMstatic 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);}#elsestatic 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 (parent == &iomem_resource && conflict->desc == IORES_DESC_DEVICE_PRIVATE_MEMORY) { pr_warn("Unaddressable device %s %pR conflicts with %pR\n", 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_HOTREMOVEstatic void append_child_to_parent(struct resource *new_parent, struct resource *new_child){ struct resource *child;
child = new_parent->child; if (child) { while (child->sibling) child = child->sibling; child->sibling = new_child; } else { new_parent->child = new_child; } new_child->parent = new_parent; new_child->sibling = NULL;}
/* * Reparent all child resources that no longer belong to "low" after a split to * "high". Note that "high" does not have any children, because "low" is the * original resource and "high" is a new resource. Treat "low" as the original * resource being split and defer its range adjustment to __adjust_resource(). */static void reparent_children_after_split(struct resource *low, struct resource *high, resource_size_t split_addr){ struct resource *child, *next, **p;
p = &low->child; while ((child = *p)) { next = child->sibling; if (child->start > split_addr) { /* unlink child */ *p = next; append_child_to_parent(high, child); } else { p = &child->sibling; } }}
/** * 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. * * 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, its children are * reassigned to the correct parent based on their range. If a child memory * resource overlaps with more than one parent, enhance the logic as needed. */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; reparent_children_after_split(res, new_res, end);
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_HOTPLUGstatic 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 };
WARN_ON(devres_release(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 4static 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 = DEFINE_RES_IO_NAMED(io_start, io_num, "reserved"); parent = &ioport_resource; } else { *res = DEFINE_RES_MEM_NAMED(io_start, io_num, "reserved"); parent = &iomem_resource; } res->flags |= IORESOURCE_BUSY; 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){ resource_size_t end = addr + size - 1; struct resource *p; int err = 0;
read_lock(&resource_lock); for_each_resource(&iomem_resource, p, false) { /* * 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_DEVMEMstatic int strict_iomem_checks = 1;#elsestatic 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)#ifdef PA_SECTION_SHIFT#define GFR_DEFAULT_ALIGN (1UL << PA_SECTION_SHIFT)#else#define GFR_DEFAULT_ALIGN PAGE_SIZE#endif
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, DIRECT_MAP_PHYSMEM_END); return end - size + 1; }
return ALIGN(max(base->start, align), 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, DIRECT_MAP_PHYSMEM_END);}
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 = DEFINE_RES_NAMED_DESC(addr, size, name, IORESOURCE_MEM, desc);
/* * 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_GPL(alloc_free_mem_region);#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);