diff options
Diffstat (limited to 'kernel/resource.c')
| -rw-r--r-- | kernel/resource.c | 884 |
1 files changed, 762 insertions, 122 deletions
diff --git a/kernel/resource.c b/kernel/resource.c index 82aea814d40..3c2237ac32d 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -7,7 +7,9 @@ * Arbitrary resource management. */ -#include <linux/module.h> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/export.h> #include <linux/errno.h> #include <linux/ioport.h> #include <linux/init.h> @@ -15,8 +17,11 @@ #include <linux/spinlock.h> #include <linux/fs.h> #include <linux/proc_fs.h> +#include <linux/sched.h> #include <linux/seq_file.h> #include <linux/device.h> +#include <linux/pfn.h> +#include <linux/mm.h> #include <asm/io.h> @@ -36,11 +41,23 @@ struct resource iomem_resource = { }; EXPORT_SYMBOL(iomem_resource); -static DEFINE_RWLOCK(resource_lock); +/* 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; +}; -#ifdef CONFIG_PROC_FS +static DEFINE_RWLOCK(resource_lock); -enum { MAX_IORES_LEVEL = 5 }; +/* + * For memory hotplug, there is no way to free resource entries allocated + * by boot mem after the system is up. So for reusing the resource entry + * we need to remember the resource. + */ +static struct resource *bootmem_resource_free; +static DEFINE_SPINLOCK(bootmem_resource_lock); static void *r_next(struct seq_file *m, void *v, loff_t *pos) { @@ -53,6 +70,10 @@ static void *r_next(struct seq_file *m, void *v, loff_t *pos) return p->sibling; } +#ifdef CONFIG_PROC_FS + +enum { MAX_IORES_LEVEL = 5 }; + static void *r_start(struct seq_file *m, loff_t *pos) __acquires(resource_lock) { @@ -131,20 +152,48 @@ static const struct file_operations proc_iomem_operations = { static int __init ioresources_init(void) { - struct proc_dir_entry *entry; - - entry = create_proc_entry("ioports", 0, NULL); - if (entry) - entry->proc_fops = &proc_ioports_operations; - entry = create_proc_entry("iomem", 0, NULL); - if (entry) - entry->proc_fops = &proc_iomem_operations; + proc_create("ioports", 0, NULL, &proc_ioports_operations); + proc_create("iomem", 0, NULL, &proc_iomem_operations); return 0; } __initcall(ioresources_init); #endif /* CONFIG_PROC_FS */ +static void free_resource(struct resource *res) +{ + if (!res) + return; + + if (!PageSlab(virt_to_head_page(res))) { + spin_lock(&bootmem_resource_lock); + res->sibling = bootmem_resource_free; + bootmem_resource_free = res; + spin_unlock(&bootmem_resource_lock); + } else { + kfree(res); + } +} + +static struct resource *alloc_resource(gfp_t flags) +{ + struct resource *res = NULL; + + spin_lock(&bootmem_resource_lock); + if (bootmem_resource_free) { + res = bootmem_resource_free; + bootmem_resource_free = res->sibling; + } + spin_unlock(&bootmem_resource_lock); + + if (res) + memset(res, 0, sizeof(struct resource)); + else + res = kzalloc(sizeof(struct resource), flags); + + return res; +} + /* Return the conflict entry if you can't request it */ static struct resource * __request_resource(struct resource *root, struct resource *new) { @@ -193,20 +242,65 @@ static int __release_resource(struct resource *old) 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 - request and reserve an I/O or memory resource + * 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, negative error code on error. + * Returns 0 for success, conflict resource on error. */ -int request_resource(struct resource *root, struct resource *new) +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; } @@ -228,13 +322,13 @@ int release_resource(struct resource *old) EXPORT_SYMBOL(release_resource); -#if defined(CONFIG_MEMORY_HOTPLUG) && !defined(CONFIG_ARCH_HAS_WALK_MEMORY) +#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. + * 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 int find_next_system_ram(struct resource *res) +static int find_next_system_ram(struct resource *res, char *name) { resource_size_t start, end; struct resource *p; @@ -250,6 +344,8 @@ static int find_next_system_ram(struct resource *res) /* system ram is just marked as IORESOURCE_MEM */ if (p->flags != res->flags) continue; + if (name && strcmp(p->name, name)) + continue; if (p->start > end) { p = NULL; break; @@ -267,22 +363,30 @@ static int find_next_system_ram(struct resource *res) res->end = p->end; return 0; } -int -walk_memory_resource(unsigned long start_pfn, unsigned long nr_pages, void *arg, - int (*func)(unsigned long, unsigned long, void *)) + +/* + * 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". + */ +int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages, + void *arg, int (*func)(unsigned long, unsigned long, void *)) { struct resource res; - unsigned long pfn, len; + unsigned long pfn, end_pfn; u64 orig_end; int ret = -1; + res.start = (u64) start_pfn << PAGE_SHIFT; res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1; res.flags = IORESOURCE_MEM | IORESOURCE_BUSY; orig_end = res.end; - while ((res.start < res.end) && (find_next_system_ram(&res) >= 0)) { - pfn = (unsigned long)(res.start >> PAGE_SHIFT); - len = (unsigned long)((res.end + 1 - res.start) >> PAGE_SHIFT); - ret = (*func)(pfn, len, arg); + 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; + if (end_pfn > pfn) + ret = (*func)(pfn, end_pfn - pfn, arg); if (ret) break; res.start = res.end + 1; @@ -293,58 +397,167 @@ walk_memory_resource(unsigned long start_pfn, unsigned long nr_pages, void *arg, #endif +static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg) +{ + return 1; +} /* - * Find empty slot in the resource tree given range and alignment. + * This generic page_is_ram() returns true if specified address is + * registered as "System RAM" in iomem_resource list. */ -static int find_resource(struct resource *root, struct resource *new, - resource_size_t size, resource_size_t min, - resource_size_t max, resource_size_t align, - void (*alignf)(void *, struct resource *, - resource_size_t, resource_size_t), - void *alignf_data) +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); + +void __weak arch_remove_reservations(struct resource *avail) +{ +} + +static resource_size_t simple_align_resource(void *data, + const struct resource *avail, + resource_size_t size, + resource_size_t align) +{ + return avail->start; +} + +static void resource_clip(struct resource *res, resource_size_t min, + resource_size_t max) +{ + if (res->start < min) + res->start = min; + if (res->end > max) + res->end = max; +} + +/* + * Find empty slot in the resource tree with the given range and + * alignment constraints + */ +static int __find_resource(struct resource *root, struct resource *old, + struct resource *new, + resource_size_t size, + struct resource_constraint *constraint) { struct resource *this = root->child; + struct resource tmp = *new, avail, alloc; - new->start = root->start; + tmp.start = root->start; /* * Skip past an allocated resource that starts at 0, since the assignment - * of this->start - 1 to new->end below would cause an underflow. + * of this->start - 1 to tmp->end below would cause an underflow. */ - if (this && this->start == 0) { - new->start = this->end + 1; + if (this && this->start == root->start) { + tmp.start = (this == old) ? old->start : this->end + 1; this = this->sibling; } for(;;) { if (this) - new->end = this->start - 1; + tmp.end = (this == old) ? this->end : this->start - 1; else - new->end = root->end; - if (new->start < min) - new->start = min; - if (new->end > max) - new->end = max; - new->start = ALIGN(new->start, align); - if (alignf) - alignf(alignf_data, new, size, align); - if (new->start < new->end && new->end - new->start >= size - 1) { - new->end = new->start + size - 1; - return 0; + tmp.end = root->end; + + if (tmp.end < tmp.start) + goto next; + + resource_clip(&tmp, constraint->min, constraint->max); + arch_remove_reservations(&tmp); + + /* Check for overflow after ALIGN() */ + avail.start = ALIGN(tmp.start, constraint->align); + avail.end = tmp.end; + avail.flags = new->flags & ~IORESOURCE_UNSET; + if (avail.start >= tmp.start) { + alloc.flags = avail.flags; + alloc.start = constraint->alignf(constraint->alignf_data, &avail, + size, constraint->align); + alloc.end = alloc.start + size - 1; + if (resource_contains(&avail, &alloc)) { + new->start = alloc.start; + new->end = alloc.end; + return 0; + } } - if (!this) + +next: if (!this || this->end == root->end) break; - new->start = this->end + 1; + + if (this != old) + tmp.start = this->end + 1; this = this->sibling; } return -EBUSY; } +/* + * Find empty slot in the resource tree given range and alignment. + */ +static int find_resource(struct resource *root, struct resource *new, + resource_size_t size, + struct resource_constraint *constraint) +{ + return __find_resource(root, NULL, new, size, constraint); +} + /** - * allocate_resource - allocate empty slot in the resource tree given range & alignment + * reallocate_resource - allocate a slot in the resource tree given range & alignment. + * The resource will be relocated if the new size cannot be reallocated in the + * current location. + * + * @root: root resource descriptor + * @old: resource descriptor desired by caller + * @newsize: new size of the resource descriptor + * @constraint: the size and alignment constraints to be met. + */ +static int reallocate_resource(struct resource *root, struct resource *old, + resource_size_t newsize, + struct resource_constraint *constraint) +{ + int err=0; + struct resource new = *old; + struct resource *conflict; + + write_lock(&resource_lock); + + if ((err = __find_resource(root, old, &new, newsize, constraint))) + goto out; + + if (resource_contains(&new, old)) { + old->start = new.start; + old->end = new.end; + goto out; + } + + if (old->child) { + err = -EBUSY; + goto out; + } + + if (resource_contains(old, &new)) { + old->start = new.start; + old->end = new.end; + } else { + __release_resource(old); + *old = new; + conflict = __request_resource(root, old); + BUG_ON(conflict); + } +out: + write_unlock(&resource_lock); + return err; +} + + +/** + * allocate_resource - allocate empty slot in the resource tree given range & alignment. + * The resource will be reallocated with a new size if it was already allocated * @root: root resource descriptor * @new: resource descriptor desired by caller * @size: requested resource region size - * @min: minimum size to allocate - * @max: maximum size to allocate + * @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 @@ -352,14 +565,32 @@ static int find_resource(struct resource *root, struct resource *new, 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, - void (*alignf)(void *, struct resource *, - resource_size_t, resource_size_t), + resource_size_t (*alignf)(void *, + const struct resource *, + resource_size_t, + resource_size_t), void *alignf_data) { int err; + struct resource_constraint constraint; + + if (!alignf) + alignf = simple_align_resource; + + constraint.min = min; + constraint.max = max; + constraint.align = align; + constraint.alignf = alignf; + constraint.alignf_data = alignf_data; + + if ( new->parent ) { + /* resource is already allocated, try reallocating with + the new constraints */ + return reallocate_resource(root, new, size, &constraint); + } write_lock(&resource_lock); - err = find_resource(root, new, size, min, max, align, alignf, alignf_data); + err = find_resource(root, new, size, &constraint); if (err >= 0 && __request_resource(root, new)) err = -EBUSY; write_unlock(&resource_lock); @@ -369,34 +600,43 @@ int allocate_resource(struct resource *root, struct resource *new, EXPORT_SYMBOL(allocate_resource); /** - * 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. + * lookup_resource - find an existing resource by a resource start address + * @root: root resource descriptor + * @start: resource start address * - * This function is equivalent to request_resource 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. + * Returns a pointer to the resource if found, NULL otherwise */ -int insert_resource(struct resource *parent, struct resource *new) +struct resource *lookup_resource(struct resource *root, resource_size_t start) { - int result; - struct resource *first, *next; + struct resource *res; - write_lock(&resource_lock); + 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) { - result = 0; first = __request_resource(parent, new); if (!first) - goto out; + return first; - result = -EBUSY; if (first == parent) - goto out; + return first; + if (WARN_ON(first == new)) /* duplicated insertion */ + return first; if ((first->start > new->start) || (first->end < new->end)) break; @@ -407,15 +647,13 @@ int insert_resource(struct resource *parent, struct resource *new) for (next = first; ; next = next->sibling) { /* Partial overlap? Bad, and unfixable */ if (next->start < new->start || next->end > new->end) - goto out; + return next; if (!next->sibling) break; if (next->sibling->start > new->end) break; } - result = 0; - new->parent = parent; new->sibling = next->sibling; new->child = first; @@ -432,38 +670,94 @@ int insert_resource(struct resource *parent, struct resource *new) next = next->sibling; next->sibling = new; } + return NULL; +} - out: +/** + * insert_resource_conflict - Inserts resource in the resource tree + * @parent: parent of the new resource + * @new: new resource to insert + * + * Returns 0 on success, conflict resource if the resource can't be inserted. + * + * This function is equivalent to request_resource_conflict when no conflict + * happens. If a conflict happens, and the conflicting resources + * entirely fit within the range of the new resource, then the new + * resource is inserted and the conflicting resources become children of + * the new resource. + */ +struct resource *insert_resource_conflict(struct resource *parent, struct resource *new) +{ + struct resource *conflict; + + write_lock(&resource_lock); + conflict = __insert_resource(parent, new); write_unlock(&resource_lock); - return result; + return conflict; } /** - * adjust_resource - modify a resource's start and size - * @res: resource to modify - * @start: new start value - * @size: new size + * insert_resource - Inserts a resource in the resource tree + * @parent: parent of the new resource + * @new: new resource to insert * - * 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. + * Returns 0 on success, -EBUSY if the resource can't be inserted. */ -int adjust_resource(struct resource *res, resource_size_t start, resource_size_t size) +int insert_resource(struct resource *parent, struct resource *new) +{ + struct resource *conflict; + + conflict = insert_resource_conflict(parent, new); + return conflict ? -EBUSY : 0; +} + +/** + * insert_resource_expand_to_fit - Insert a resource into the resource tree + * @root: root resource descriptor + * @new: new resource to insert + * + * Insert a resource into the resource tree, possibly expanding it in order + * to make it encompass any conflicting resources. + */ +void insert_resource_expand_to_fit(struct resource *root, struct resource *new) +{ + if (new->parent) + return; + + write_lock(&resource_lock); + for (;;) { + struct resource *conflict; + + conflict = __insert_resource(root, new); + if (!conflict) + break; + if (conflict == root) + break; + + /* Ok, expand resource to cover the conflict, then try again .. */ + if (conflict->start < new->start) + new->start = conflict->start; + if (conflict->end > new->end) + new->end = conflict->end; + + printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name); + } + write_unlock(&resource_lock); +} + +static int __adjust_resource(struct resource *res, resource_size_t start, + resource_size_t size) { struct resource *tmp, *parent = res->parent; resource_size_t end = start + size - 1; int result = -EBUSY; - write_lock(&resource_lock); + if (!parent) + goto skip; if ((start < parent->start) || (end > parent->end)) goto out; - for (tmp = res->child; tmp; tmp = tmp->sibling) { - if ((tmp->start < start) || (tmp->end > end)) - goto out; - } - if (res->sibling && (res->sibling->start <= end)) goto out; @@ -475,17 +769,146 @@ int adjust_resource(struct resource *res, resource_size_t start, resource_size_t 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: - write_unlock(&resource_lock); return result; } +/** + * adjust_resource - modify a resource's start and size + * @res: resource to modify + * @start: new start value + * @size: new size + * + * Given an existing resource, change its start and size to match the + * arguments. Returns 0 on success, -EBUSY if it can't fit. + * Existing children of the resource are assumed to be immutable. + */ +int adjust_resource(struct resource *res, resource_size_t start, + resource_size_t size) +{ + int result; + + write_lock(&resource_lock); + result = __adjust_resource(res, start, size); + write_unlock(&resource_lock); + return result; +} EXPORT_SYMBOL(adjust_resource); +static void __init __reserve_region_with_split(struct resource *root, + resource_size_t start, resource_size_t end, + const char *name) +{ + struct resource *parent = root; + struct resource *conflict; + struct resource *res = alloc_resource(GFP_ATOMIC); + struct resource *next_res = NULL; + + if (!res) + return; + + res->name = name; + res->start = start; + res->end = end; + res->flags = IORESOURCE_BUSY; + + while (1) { + + conflict = __request_resource(parent, res); + if (!conflict) { + if (!next_res) + break; + res = next_res; + next_res = NULL; + continue; + } + + /* conflict covered whole area */ + if (conflict->start <= res->start && + conflict->end >= res->end) { + free_resource(res); + WARN_ON(next_res); + break; + } + + /* failed, split and try again */ + if (conflict->start > res->start) { + end = res->end; + res->end = conflict->start - 1; + if (conflict->end < end) { + next_res = alloc_resource(GFP_ATOMIC); + if (!next_res) { + free_resource(res); + break; + } + next_res->name = name; + next_res->start = conflict->end + 1; + next_res->end = end; + next_res->flags = IORESOURCE_BUSY; + } + } else { + res->start = conflict->end + 1; + } + } + +} + +void __init reserve_region_with_split(struct resource *root, + resource_size_t start, resource_size_t end, + const char *name) +{ + int abort = 0; + + write_lock(&resource_lock); + if (root->start > start || root->end < end) { + pr_err("requested range [0x%llx-0x%llx] not in root %pr\n", + (unsigned long long)start, (unsigned long long)end, + root); + if (start > root->end || end < root->start) + abort = 1; + else { + if (end > root->end) + end = root->end; + if (start < root->start) + start = root->start; + pr_err("fixing request to [0x%llx-0x%llx]\n", + (unsigned long long)start, + (unsigned long long)end); + } + dump_stack(); + } + if (!abort) + __reserve_region_with_split(root, start, end, name); + write_unlock(&resource_lock); +} + +/** + * resource_alignment - calculate resource's alignment + * @res: resource pointer + * + * Returns alignment on success, 0 (invalid alignment) on failure. + */ +resource_size_t resource_alignment(struct resource *res) +{ + switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) { + case IORESOURCE_SIZEALIGN: + return resource_size(res); + case IORESOURCE_STARTALIGN: + return res->start; + default: + return 0; + } +} + /* * This is compatibility stuff for IO resources. * @@ -499,46 +922,60 @@ EXPORT_SYMBOL(adjust_resource); * release_region releases a matching busy region. */ +static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait); + /** * __request_region - create a new busy resource region * @parent: parent resource descriptor * @start: resource start address * @n: resource region size * @name: reserving caller's ID string + * @flags: IO resource flags */ struct resource * __request_region(struct resource *parent, resource_size_t start, resource_size_t n, - const char *name) + const char *name, int flags) { - struct resource *res = kzalloc(sizeof(*res), GFP_KERNEL); + DECLARE_WAITQUEUE(wait, current); + struct resource *res = alloc_resource(GFP_KERNEL); - if (res) { - res->name = name; - res->start = start; - res->end = start + n - 1; - res->flags = IORESOURCE_BUSY; + if (!res) + return NULL; - write_lock(&resource_lock); + res->name = name; + res->start = start; + res->end = start + n - 1; + res->flags = resource_type(parent); + res->flags |= IORESOURCE_BUSY | flags; - for (;;) { - struct resource *conflict; + write_lock(&resource_lock); - conflict = __request_resource(parent, res); - if (!conflict) - break; - if (conflict != parent) { - parent = conflict; - if (!(conflict->flags & IORESOURCE_BUSY)) - continue; - } + for (;;) { + struct resource *conflict; - /* Uhhuh, that didn't work out.. */ - kfree(res); - res = NULL; + conflict = __request_resource(parent, res); + if (!conflict) break; + if (conflict != parent) { + parent = conflict; + if (!(conflict->flags & IORESOURCE_BUSY)) + 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; } - write_unlock(&resource_lock); + /* Uhhuh, that didn't work out.. */ + free_resource(res); + res = NULL; + break; } + write_unlock(&resource_lock); return res; } EXPORT_SYMBOL(__request_region); @@ -563,12 +1000,12 @@ int __check_region(struct resource *parent, resource_size_t start, { struct resource * res; - res = __request_region(parent, start, n, "check-region"); + res = __request_region(parent, start, n, "check-region", 0); if (!res) return -EBUSY; release_resource(res); - kfree(res); + free_resource(res); return 0; } EXPORT_SYMBOL(__check_region); @@ -606,7 +1043,9 @@ void __release_region(struct resource *parent, resource_size_t start, break; *p = res->sibling; write_unlock(&resource_lock); - kfree(res); + if (res->flags & IORESOURCE_MUXED) + wake_up(&muxed_resource_wait); + free_resource(res); return; } p = &res->sibling; @@ -620,6 +1059,109 @@ void __release_region(struct resource *parent, resource_size_t start, } EXPORT_SYMBOL(__release_region); +#ifdef CONFIG_MEMORY_HOTREMOVE +/** + * release_mem_region_adjustable - release a previously reserved memory region + * @parent: parent resource descriptor + * @start: resource start address + * @size: resource region size + * + * This interface is intended for memory hot-delete. The requested region + * is released from a currently busy memory resource. The requested region + * must either match exactly or fit into a single busy resource entry. In + * the latter case, the remaining resource is adjusted accordingly. + * Existing children of the busy memory resource must be immutable in the + * request. + * + * Note: + * - Additional release conditions, such as overlapping region, can be + * supported after they are confirmed as valid cases. + * - When a busy memory resource gets split into two entries, the code + * assumes that all children remain in the lower address entry for + * simplicity. Enhance this logic when necessary. + */ +int release_mem_region_adjustable(struct resource *parent, + resource_size_t start, resource_size_t size) +{ + struct resource **p; + struct resource *res; + struct resource *new_res; + resource_size_t end; + int ret = -EINVAL; + + end = start + size - 1; + if ((start < parent->start) || (end > parent->end)) + return ret; + + /* The alloc_resource() result gets checked later */ + new_res = alloc_resource(GFP_KERNEL); + + p = &parent->child; + write_lock(&resource_lock); + + while ((res = *p)) { + if (res->start >= end) + break; + + /* look for the next resource if it does not fit into */ + if (res->start > start || res->end < end) { + p = &res->sibling; + continue; + } + + if (!(res->flags & IORESOURCE_MEM)) + break; + + if (!(res->flags & IORESOURCE_BUSY)) { + p = &res->child; + continue; + } + + /* found the target resource; let's adjust accordingly */ + if (res->start == start && res->end == end) { + /* free the whole entry */ + *p = res->sibling; + free_resource(res); + ret = 0; + } else if (res->start == start && res->end != end) { + /* adjust the start */ + ret = __adjust_resource(res, end + 1, + res->end - end); + } else if (res->start != start && res->end == end) { + /* adjust the end */ + ret = __adjust_resource(res, res->start, + start - res->start); + } else { + /* split into two entries */ + if (!new_res) { + ret = -ENOMEM; + break; + } + new_res->name = res->name; + new_res->start = end + 1; + new_res->end = res->end; + new_res->flags = res->flags; + new_res->parent = res->parent; + new_res->sibling = res->sibling; + new_res->child = NULL; + + ret = __adjust_resource(res, res->start, + start - res->start); + if (ret) + break; + res->sibling = new_res; + new_res = NULL; + } + + break; + } + + write_unlock(&resource_lock); + free_resource(new_res); + return ret; +} +#endif /* CONFIG_MEMORY_HOTREMOVE */ + /* * Managed region resource */ @@ -660,7 +1202,7 @@ struct resource * __devm_request_region(struct device *dev, dr->start = start; dr->n = n; - res = __request_region(parent, start, n, name); + res = __request_region(parent, start, n, name, 0); if (res) devres_add(dev, dr); else @@ -691,7 +1233,7 @@ static int __init reserve_setup(char *str) static struct resource reserve[MAXRESERVE]; for (;;) { - int io_start, io_num; + unsigned int io_start, io_num; int x = reserved; if (get_option (&str, &io_start) != 2) @@ -713,3 +1255,101 @@ static int __init reserve_setup(char *str) } __setup("reserve=", reserve_setup); + +/* + * Check if the requested addr and size spans more than any slot in the + * iomem resource tree. + */ +int iomem_map_sanity_check(resource_size_t addr, unsigned long size) +{ + struct resource *p = &iomem_resource; + int err = 0; + loff_t l; + + read_lock(&resource_lock); + for (p = p->child; p ; p = r_next(NULL, p, &l)) { + /* + * We can probably skip the resources without + * IORESOURCE_IO attribute? + */ + if (p->start >= addr + size) + continue; + if (p->end < addr) + continue; + if (PFN_DOWN(p->start) <= PFN_DOWN(addr) && + PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1)) + continue; + /* + * if a resource is "BUSY", it's not a hardware resource + * but a driver mapping of such a resource; we don't want + * to warn for those; some drivers legitimately map only + * partial hardware resources. (example: vesafb) + */ + if (p->flags & IORESOURCE_BUSY) + continue; + + printk(KERN_WARNING "resource sanity check: requesting [mem %#010llx-%#010llx], which spans more than %s %pR\n", + (unsigned long long)addr, + (unsigned long long)(addr + size - 1), + p->name, p); + err = -1; + break; + } + read_unlock(&resource_lock); + + return err; +} + +#ifdef CONFIG_STRICT_DEVMEM +static int strict_iomem_checks = 1; +#else +static int strict_iomem_checks; +#endif + +/* + * check if an address is reserved in the iomem resource tree + * returns 1 if reserved, 0 if not reserved. + */ +int iomem_is_exclusive(u64 addr) +{ + struct resource *p = &iomem_resource; + int err = 0; + loff_t l; + int size = PAGE_SIZE; + + if (!strict_iomem_checks) + return 0; + + addr = addr & PAGE_MASK; + + read_lock(&resource_lock); + for (p = p->child; p ; p = r_next(NULL, p, &l)) { + /* + * We can probably skip the resources without + * IORESOURCE_IO attribute? + */ + if (p->start >= addr + size) + break; + if (p->end < addr) + continue; + if (p->flags & IORESOURCE_BUSY && + p->flags & IORESOURCE_EXCLUSIVE) { + err = 1; + break; + } + } + read_unlock(&resource_lock); + + return err; +} + +static int __init strict_iomem(char *str) +{ + if (strstr(str, "relaxed")) + strict_iomem_checks = 0; + if (strstr(str, "strict")) + strict_iomem_checks = 1; + return 1; +} + +__setup("iomem=", strict_iomem); |