diff options
Diffstat (limited to 'kernel/resource.c')
| -rw-r--r-- | kernel/resource.c | 1410 |
1 files changed, 1102 insertions, 308 deletions
diff --git a/kernel/resource.c b/kernel/resource.c index 3f285dce9347..e4e9bac12e6e 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0-only /* * linux/kernel/resource.c * @@ -17,11 +18,17 @@ #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> @@ -41,35 +48,38 @@ struct resource iomem_resource = { }; EXPORT_SYMBOL(iomem_resource); -/* constraints to be met while allocating resources */ -struct resource_constraint { - resource_size_t min, max, align; - resource_size_t (*alignf)(void *, const struct resource *, - resource_size_t, resource_size_t); - void *alignf_data; -}; - static DEFINE_RWLOCK(resource_lock); /* - * For memory hotplug, there is no way to free resource entries allocated - * by boot mem after the system is up. So for reusing the resource entry - * we need to remember the resource. + * 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 *bootmem_resource_free; -static DEFINE_SPINLOCK(bootmem_resource_lock); - -static void *r_next(struct seq_file *m, void *v, loff_t *pos) +static struct resource *next_resource(struct resource *p, bool skip_children, + struct resource *subtree_root) { - struct resource *p = v; - (*pos)++; - if (p->child) + if (!skip_children && p->child) return p->child; - while (!p->sibling && p->parent) + 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 = 5 }; @@ -77,14 +87,28 @@ enum { MAX_IORES_LEVEL = 5 }; static void *r_start(struct seq_file *m, loff_t *pos) __acquires(resource_lock) { - struct resource *p = m->private; - loff_t l = 0; + struct resource *root = pde_data(file_inode(m->file)); + struct resource *p; + loff_t l = *pos; + read_lock(&resource_lock); - for (p = p->child; p && l < *pos; p = r_next(m, p, &l)) - ; + 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) { @@ -93,18 +117,27 @@ static void r_stop(struct seq_file *m, void *v) static int r_show(struct seq_file *m, void *v) { - struct resource *root = m->private; + 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, (unsigned long long) r->start, - width, (unsigned long long) r->end, + width, start, + width, end, r->name ? r->name : "<BAD>"); return 0; } @@ -116,44 +149,11 @@ static const struct seq_operations resource_op = { .show = r_show, }; -static int ioports_open(struct inode *inode, struct file *file) -{ - int res = seq_open(file, &resource_op); - if (!res) { - struct seq_file *m = file->private_data; - m->private = &ioport_resource; - } - return res; -} - -static int iomem_open(struct inode *inode, struct file *file) -{ - int res = seq_open(file, &resource_op); - if (!res) { - struct seq_file *m = file->private_data; - m->private = &iomem_resource; - } - return res; -} - -static const struct file_operations proc_ioports_operations = { - .open = ioports_open, - .read = seq_read, - .llseek = seq_lseek, - .release = seq_release, -}; - -static const struct file_operations proc_iomem_operations = { - .open = iomem_open, - .read = seq_read, - .llseek = seq_lseek, - .release = seq_release, -}; - static int __init ioresources_init(void) { - proc_create("ioports", 0, NULL, &proc_ioports_operations); - proc_create("iomem", 0, NULL, &proc_iomem_operations); + 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); @@ -162,36 +162,19 @@ __initcall(ioresources_init); static void free_resource(struct resource *res) { - if (!res) - return; - - if (!PageSlab(virt_to_head_page(res))) { - spin_lock(&bootmem_resource_lock); - res->sibling = bootmem_resource_free; - bootmem_resource_free = res; - spin_unlock(&bootmem_resource_lock); - } else { + /** + * 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) { - struct resource *res = NULL; - - spin_lock(&bootmem_resource_lock); - if (bootmem_resource_free) { - res = bootmem_resource_free; - bootmem_resource_free = res->sibling; - } - spin_unlock(&bootmem_resource_lock); - - if (res) - memset(res, 0, sizeof(struct resource)); - else - res = kzalloc(sizeof(struct resource), flags); - - return res; + return kzalloc(sizeof(struct resource), flags); } /* Return the conflict entry if you can't request it */ @@ -223,9 +206,9 @@ static struct resource * __request_resource(struct resource *root, struct resour } } -static int __release_resource(struct resource *old) +static int __release_resource(struct resource *old, bool release_child) { - struct resource *tmp, **p; + struct resource *tmp, **p, *chd; p = &old->parent->child; for (;;) { @@ -233,7 +216,17 @@ static int __release_resource(struct resource *old) if (!tmp) break; if (tmp == old) { - *p = tmp->sibling; + 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; } @@ -315,95 +308,251 @@ int release_resource(struct resource *old) int retval; write_lock(&resource_lock); - retval = __release_resource(old); + retval = __release_resource(old, true); write_unlock(&resource_lock); return retval; } EXPORT_SYMBOL(release_resource); -#if !defined(CONFIG_ARCH_HAS_WALK_MEMORY) -/* - * Finds the lowest memory reosurce exists within [res->start.res->end) - * the caller must specify res->start, res->end, res->flags and "name". - * If found, returns 0, res is overwritten, if not found, returns -1. +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_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_system_ram(struct resource *res, char *name) +static int find_next_iomem_res(resource_size_t start, resource_size_t end, + unsigned long flags, unsigned long desc, + struct resource *res) { - resource_size_t start, end; + /* Skip children until we find a top level range that matches */ + bool skip_children = true; struct resource *p; - BUG_ON(!res); + if (!res) + return -EINVAL; - start = res->start; - end = res->end; - BUG_ON(start >= end); + if (start >= end) + return -EINVAL; read_lock(&resource_lock); - for (p = iomem_resource.child; p ; p = p->sibling) { - /* system ram is just marked as IORESOURCE_MEM */ - if (p->flags != res->flags) - continue; - if (name && strcmp(p->name, name)) - continue; + + for_each_resource(&iomem_resource, p, skip_children) { + /* If we passed the resource we are looking for, stop */ if (p->start > end) { p = NULL; break; } - if ((p->end >= start) && (p->start < end)) + + /* 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); - if (!p) - return -1; - /* copy data */ - if (res->start < p->start) - res->start = p->start; - if (res->end > p->end) - res->end = p->end; - return 0; + 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, 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 = kvcalloc(rams_size, sizeof(struct resource), GFP_KERNEL); + 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 callback against all memory range of "System RAM" - * which are marked as IORESOURCE_MEM and IORESOUCE_BUSY. - * Now, this function is only for "System RAM". + * 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 *)) + 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; - u64 orig_end; - int ret = -1; + int ret = -EINVAL; - res.start = (u64) start_pfn << PAGE_SHIFT; - res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1; - res.flags = IORESOURCE_MEM | IORESOURCE_BUSY; - orig_end = res.end; - while ((res.start < res.end) && - (find_next_system_ram(&res, "System RAM") >= 0)) { - pfn = (res.start + PAGE_SIZE - 1) >> PAGE_SHIFT; - end_pfn = (res.end + 1) >> PAGE_SHIFT; + 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; - res.start = res.end + 1; - res.end = orig_end; + start = res.end + 1; } return ret; } -#endif - static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg) { return 1; } + /* * This generic page_is_ram() returns true if specified address is - * registered as "System RAM" in iomem_resource list. + * registered as System RAM in iomem_resource list. */ int __weak page_is_ram(unsigned long pfn) { @@ -411,16 +560,104 @@ int __weak page_is_ram(unsigned long pfn) } EXPORT_SYMBOL_GPL(page_is_ram); -void __weak arch_remove_reservations(struct resource *avail) +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; } -static resource_size_t simple_align_resource(void *data, - const struct resource *avail, - resource_size_t size, - resource_size_t align) +/** + * 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) { - return avail->start; } static void resource_clip(struct resource *res, resource_size_t min, @@ -432,22 +669,17 @@ static void resource_clip(struct resource *res, resource_size_t min, res->end = max; } -static bool resource_contains(struct resource *res1, struct resource *res2) -{ - return res1->start <= res2->start && res1->end >= res2->end; -} - /* - * Find empty slot in the resource tree with the given range and + * Find empty space 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) +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 tmp = *new, avail, alloc; + resource_alignf alignf = constraint->alignf; tmp.start = root->start; /* @@ -471,14 +703,20 @@ static int __find_resource(struct resource *root, struct resource *old, arch_remove_reservations(&tmp); /* Check for overflow after ALIGN() */ - avail = *new; avail.start = ALIGN(tmp.start, constraint->align); avail.end = tmp.end; + avail.flags = new->flags & ~IORESOURCE_UNSET; if (avail.start >= tmp.start) { - alloc.start = constraint->alignf(constraint->alignf_data, &avail, - size, constraint->align); + alloc.flags = avail.flags; + if (alignf) { + alloc.start = alignf(constraint->alignf_data, + &avail, size, constraint->align); + } else { + alloc.start = avail.start; + } alloc.end = alloc.start + size - 1; - if (resource_contains(&avail, &alloc)) { + if (alloc.start <= alloc.end && + resource_contains(&avail, &alloc)) { new->start = alloc.start; new->end = alloc.end; return 0; @@ -495,15 +733,27 @@ next: if (!this || this->end == root->end) return -EBUSY; } -/* - * Find empty slot in the resource tree given range and alignment. +/** + * 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. */ -static int find_resource(struct resource *root, struct resource *new, +int find_resource_space(struct resource *root, struct resource *new, resource_size_t size, - struct resource_constraint *constraint) + struct resource_constraint *constraint) { - return __find_resource(root, NULL, new, size, 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. @@ -513,11 +763,11 @@ static int find_resource(struct resource *root, struct resource *new, * @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. + * @constraint: the memory range and alignment constraints to be met. */ -int reallocate_resource(struct resource *root, struct resource *old, - resource_size_t newsize, - struct resource_constraint *constraint) +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; @@ -525,7 +775,7 @@ int reallocate_resource(struct resource *root, struct resource *old, write_lock(&resource_lock); - if ((err = __find_resource(root, old, &new, newsize, constraint))) + if ((err = __find_resource_space(root, old, &new, newsize, constraint))) goto out; if (resource_contains(&new, old)) { @@ -543,7 +793,7 @@ int reallocate_resource(struct resource *root, struct resource *old, old->start = new.start; old->end = new.end; } else { - __release_resource(old); + __release_resource(old, true); *old = new; conflict = __request_resource(root, old); BUG_ON(conflict); @@ -569,18 +819,12 @@ out: 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), + resource_alignf alignf, void *alignf_data) { int err; struct resource_constraint constraint; - if (!alignf) - alignf = simple_align_resource; - constraint.min = min; constraint.max = max; constraint.align = align; @@ -594,7 +838,7 @@ int allocate_resource(struct resource *root, struct resource *new, } write_lock(&resource_lock); - err = find_resource(root, new, size, &constraint); + err = find_resource_space(root, new, size, &constraint); if (err >= 0 && __request_resource(root, new)) err = -EBUSY; write_unlock(&resource_lock); @@ -689,6 +933,9 @@ static struct resource * __insert_resource(struct resource *parent, struct resou * 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) { @@ -706,6 +953,9 @@ struct resource *insert_resource_conflict(struct resource *parent, struct resour * @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) { @@ -714,6 +964,7 @@ int insert_resource(struct resource *parent, struct resource *new) 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 @@ -744,10 +995,43 @@ void insert_resource_expand_to_fit(struct resource *root, struct resource *new) if (conflict->end > new->end) new->end = conflict->end; - printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name); + 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) @@ -797,7 +1081,7 @@ skip: * Existing children of the resource are assumed to be immutable. */ int adjust_resource(struct resource *res, resource_size_t start, - resource_size_t size) + resource_size_t size) { int result; @@ -808,14 +1092,15 @@ int adjust_resource(struct resource *res, resource_size_t start, } 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) +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; @@ -823,7 +1108,8 @@ static void __init __reserve_region_with_split(struct resource *root, res->name = name; res->start = start; res->end = end; - res->flags = IORESOURCE_BUSY; + res->flags = type | IORESOURCE_BUSY; + res->desc = IORES_DESC_NONE; while (1) { @@ -857,7 +1143,8 @@ static void __init __reserve_region_with_split(struct resource *root, next_res->name = name; next_res->start = conflict->end + 1; next_res->end = end; - next_res->flags = IORESOURCE_BUSY; + next_res->flags = type | IORESOURCE_BUSY; + next_res->desc = IORES_DESC_NONE; } } else { res->start = conflict->end + 1; @@ -866,9 +1153,9 @@ static void __init __reserve_region_with_split(struct resource *root, } -void __init reserve_region_with_split(struct resource *root, - resource_size_t start, resource_size_t end, - const char *name) +void __init +reserve_region_with_split(struct resource *root, resource_size_t start, + resource_size_t end, const char *name) { int abort = 0; @@ -921,49 +1208,95 @@ resource_size_t resource_alignment(struct resource *res) * * request_region creates a new busy region. * - * check_region returns non-zero if the area is already busy. - * * release_region releases a matching busy region. */ static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait); -/** - * __request_region - create a new busy resource region - * @parent: parent resource descriptor - * @start: resource start address - * @n: resource region size - * @name: reserving caller's ID string - * @flags: IO resource flags - */ -struct resource * __request_region(struct resource *parent, +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); - struct resource *res = alloc_resource(GFP_KERNEL); - - if (!res) - return NULL; res->name = name; res->start = start; res->end = start + n - 1; - res->flags = IORESOURCE_BUSY; - res->flags |= flags; - - write_lock(&resource_lock); 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) { - parent = conflict; - if (!(conflict->flags & IORESOURCE_BUSY)) + if (!(conflict->flags & IORESOURCE_BUSY)) { + parent = conflict; continue; + } } if (conflict->flags & flags & IORESOURCE_MUXED) { add_wait_queue(&muxed_resource_wait, &wait); @@ -975,44 +1308,45 @@ struct resource * __request_region(struct resource *parent, continue; } /* Uhhuh, that didn't work out.. */ - free_resource(res); - res = NULL; - break; + return -EBUSY; } - write_unlock(&resource_lock); - return res; + + return 0; } -EXPORT_SYMBOL(__request_region); /** - * __check_region - check if a resource region is busy or free + * __request_region - create a new busy resource region * @parent: parent resource descriptor * @start: resource start address * @n: resource region size - * - * Returns 0 if the region is free at the moment it is checked, - * returns %-EBUSY if the region is busy. - * - * NOTE: - * This function is deprecated because its use is racy. - * Even if it returns 0, a subsequent call to request_region() - * may fail because another driver etc. just allocated the region. - * Do NOT use it. It will be removed from the kernel. + * @name: reserving caller's ID string + * @flags: IO resource flags */ -int __check_region(struct resource *parent, resource_size_t start, - resource_size_t n) +struct resource *__request_region(struct resource *parent, + resource_size_t start, resource_size_t n, + const char *name, int flags) { - struct resource * res; + struct resource *res = alloc_resource(GFP_KERNEL); + int ret; - res = __request_region(parent, start, n, "check-region", 0); if (!res) - return -EBUSY; + return NULL; - release_resource(res); - free_resource(res); - return 0; + 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(__check_region); +EXPORT_SYMBOL(__request_region); /** * __release_region - release a previously reserved resource region @@ -1023,7 +1357,7 @@ EXPORT_SYMBOL(__check_region); * The described resource region must match a currently busy region. */ void __release_region(struct resource *parent, resource_size_t start, - resource_size_t n) + resource_size_t n) { struct resource **p; resource_size_t end; @@ -1057,16 +1391,54 @@ void __release_region(struct resource *parent, resource_size_t start, write_unlock(&resource_lock); - printk(KERN_WARNING "Trying to free nonexistent resource " - "<%016llx-%016llx>\n", (unsigned long long)start, - (unsigned long long)end); + pr_warn("Trying to free nonexistent resource <%pa-%pa>\n", &start, &end); } EXPORT_SYMBOL(__release_region); #ifdef CONFIG_MEMORY_HOTREMOVE +static 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 - * @parent: parent resource descriptor * @start: resource start address * @size: resource region size * @@ -1074,31 +1446,36 @@ EXPORT_SYMBOL(__release_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. + * - 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. */ -int release_mem_region_adjustable(struct resource *parent, - resource_size_t start, resource_size_t size) +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; - struct resource *new_res; resource_size_t end; - int ret = -EINVAL; end = start + size - 1; - if ((start < parent->start) || (end > parent->end)) - return ret; + if (WARN_ON_ONCE((start < parent->start) || (end > parent->end))) + return; - /* The alloc_resource() result gets checked later */ - new_res = alloc_resource(GFP_KERNEL); + /* + * 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); @@ -1126,32 +1503,36 @@ int release_mem_region_adjustable(struct resource *parent, /* free the whole entry */ *p = res->sibling; free_resource(res); - ret = 0; } else if (res->start == start && res->end != end) { /* adjust the start */ - ret = __adjust_resource(res, end + 1, - res->end - end); + WARN_ON_ONCE(__adjust_resource(res, end + 1, + res->end - end)); } else if (res->start != start && res->end == end) { /* adjust the end */ - ret = __adjust_resource(res, res->start, - start - res->start); + WARN_ON_ONCE(__adjust_resource(res, res->start, + start - res->start)); } else { - /* split into two entries */ + /* split into two entries - we need a new resource */ if (!new_res) { - ret = -ENOMEM; - break; + 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); - ret = __adjust_resource(res, res->start, - start - res->start); - if (ret) + if (WARN_ON_ONCE(__adjust_resource(res, res->start, + start - res->start))) break; res->sibling = new_res; new_res = NULL; @@ -1162,13 +1543,142 @@ int release_mem_region_adjustable(struct resource *parent, write_unlock(&resource_lock); free_resource(new_res); - return ret; } #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; @@ -1190,9 +1700,9 @@ static int devm_region_match(struct device *dev, void *res, void *match_data) 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 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; @@ -1221,14 +1731,13 @@ void __devm_release_region(struct device *dev, struct resource *parent, { struct region_devres match_data = { parent, start, n }; - __release_region(parent, start, n); - WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match, + WARN_ON(devres_release(dev, devm_region_release, devm_region_match, &match_data)); } EXPORT_SYMBOL(__devm_release_region); /* - * Called from init/main.c to reserve IO ports. + * Reserve I/O ports or memory based on "reserve=" kernel parameter. */ #define MAXRESERVE 4 static int __init reserve_setup(char *str) @@ -1239,25 +1748,33 @@ static int __init reserve_setup(char *str) for (;;) { unsigned int io_start, io_num; int x = reserved; + struct resource *parent; - if (get_option (&str, &io_start) != 2) + if (get_option(&str, &io_start) != 2) break; - if (get_option (&str, &io_num) == 0) + if (get_option(&str, &io_num) == 0) break; if (x < MAXRESERVE) { struct resource *res = reserve + x; - res->name = "reserved"; - res->start = io_start; - res->end = io_start + io_num - 1; - res->flags = IORESOURCE_BUSY; - res->child = NULL; - if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0) + + /* + * 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); /* @@ -1266,22 +1783,22 @@ __setup("reserve=", reserve_setup); */ int iomem_map_sanity_check(resource_size_t addr, unsigned long size) { - struct resource *p = &iomem_resource; + resource_size_t end = addr + size - 1; + struct resource *p; int err = 0; - loff_t l; read_lock(&resource_lock); - for (p = p->child; p ; p = r_next(NULL, p, &l)) { + for_each_resource(&iomem_resource, p, false) { /* * We can probably skip the resources without * IORESOURCE_IO attribute? */ - if (p->start >= addr + size) + if (p->start > end) continue; if (p->end < addr) continue; if (PFN_DOWN(p->start) <= PFN_DOWN(addr) && - PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1)) + PFN_DOWN(p->end) >= PFN_DOWN(end)) continue; /* * if a resource is "BUSY", it's not a hardware resource @@ -1292,13 +1809,8 @@ int iomem_map_sanity_check(resource_size_t addr, unsigned long size) if (p->flags & IORESOURCE_BUSY) continue; - printk(KERN_WARNING "resource map sanity check conflict: " - "0x%llx 0x%llx 0x%llx 0x%llx %s\n", - (unsigned long long)addr, - (unsigned long long)(addr + size - 1), - (unsigned long long)p->start, - (unsigned long long)p->end, - p->name); + pr_warn("resource sanity check: requesting [mem %pa-%pa], which spans more than %s %pR\n", + &addr, &end, p->name, p); err = -1; break; } @@ -1314,34 +1826,50 @@ static int strict_iomem_checks; #endif /* - * check if an address is reserved in the iomem resource tree - * returns 1 if reserved, 0 if not reserved. + * 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. */ -int iomem_is_exclusive(u64 addr) +bool resource_is_exclusive(struct resource *root, u64 addr, resource_size_t size) { - struct resource *p = &iomem_resource; - int err = 0; - loff_t l; - int size = PAGE_SIZE; - - if (!strict_iomem_checks) - return 0; - - addr = addr & PAGE_MASK; + 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 (p = p->child; p ; p = r_next(NULL, p, &l)) { + for_each_resource(root, p, skip_children) { + if (p->start >= addr + size) + break; + if (p->end < addr) { + skip_children = true; + continue; + } + skip_children = false; + /* - * We can probably skip the resources without - * IORESOURCE_IO attribute? + * 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->start >= addr + size) + if ((p->flags & exclusive_system_ram) == exclusive_system_ram) { + err = true; break; - if (p->end < addr) + } + + /* + * 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 (p->flags & IORESOURCE_BUSY && - p->flags & IORESOURCE_EXCLUSIVE) { - err = 1; + if (IS_ENABLED(CONFIG_IO_STRICT_DEVMEM) + || p->flags & IORESOURCE_EXCLUSIVE) { + err = true; break; } } @@ -1350,6 +1878,228 @@ int iomem_is_exclusive(u64 addr) 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")) @@ -1359,4 +2109,48 @@ static int __init strict_iomem(char *str) 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); |