// SPDX-License-Identifier: GPL-2.0-only
/*
* linux/kernel/resource.c
*
* Copyright (C) 1999 Linus Torvalds
* Copyright (C) 1999 Martin Mares <[email protected]>
*
* 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);
static DEFINE_RWLOCK(resource_lock);
static struct resource *next_resource(struct resource *p, bool skip_children)
{
if (!skip_children && p->child)
return p->child;
while (!p->sibling && p->parent)
p = p->parent;
return p->sibling;
}
#define for_each_resource(_root, _p, _skip_children) \
for ((_p) = (_root)->child; (_p); (_p) = next_resource(_p, _skip_children))
#ifdef CONFIG_PROC_FS
enum { MAX_IORES_LEVEL = 5 };
static void *r_start(struct seq_file *m, loff_t *pos)
__acquires(resource_lock)
{
struct resource *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);
}
static void r_stop(struct seq_file *m, void *v)
__releases(resource_lock)
{
read_unlock(&resource_lock);
}
static int r_show(struct seq_file *m, void *v)
{
struct resource *root = pde_data(file_inode(m->file));
struct resource *r = v, *p;
unsigned long long start, end;
int width = root->end < 0x10000 ? 4 : 8;
int depth;
for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent)
if (p->parent == root)
break;
if (file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN)) {
start = r->start;
end = r->end;
} else {
start = end = 0;
}
seq_printf(m, "%*s%0*llx-%0*llx : %s\n",
depth * 2, "",
width, start,
width, end,
r->name ? r->name : "<BAD>");
return 0;
}
static const struct seq_operations resource_op = {
.start = r_start,
.next = r_next,
.stop = r_stop,
.show = r_show,
};
static int __init ioresources_init(void)
{
proc_create_seq_data("ioports", 0, NULL, &resource_op,
&ioport_resource);
proc_create_seq_data("iomem", 0, NULL, &resource_op, &iomem_resource);
return 0;
}
__initcall(ioresources_init);
#endif /* CONFIG_PROC_FS */
static void free_resource(struct resource *res)
{
/**
* If the resource was allocated using memblock early during boot
* we'll leak it here: we can only return full pages back to the
* buddy and trying to be smart and reusing them eventually in
* alloc_resource() overcomplicates resource handling.
*/
if (res && PageSlab(virt_to_head_page(res)))
kfree(res);
}
static struct resource *alloc_resource(gfp_t flags)
{
return kzalloc(sizeof(struct resource), flags);
}
/* Return the conflict entry if you can't request it */
static struct resource * __request_resource(struct resource *root, struct resource *new)
{
resource_size_t start = new->start;
resource_size_t end = new->end;
struct resource *tmp, **p;
if (end < start)
return root;
if (start < root->start)
return root;
if (end > root->end)
return root;
p = &root->child;
for (;;) {
tmp = *p;
if (!tmp || tmp->start > end) {
new->sibling = tmp;
*p = new;
new->parent = root;
return NULL;
}
p = &tmp->sibling;
if (tmp->end < start)
continue;
return tmp;
}
}
static int __release_resource(struct resource *old, bool release_child)
{
struct resource *tmp, **p, *chd;
p = &old->parent->child;
for (;;) {
tmp = *p;
if (!tmp)
break;
if (tmp == old) {
if (release_child || !(tmp->child)) {
*p = tmp->sibling;
} else {
for (chd = tmp->child;; chd = chd->sibling) {
chd->parent = tmp->parent;
if (!(chd->sibling))
break;
}
*p = tmp->child;
chd->sibling = tmp->sibling;
}
old->parent = NULL;
return 0;
}
p = &tmp->sibling;
}
return -EINVAL;
}
static void __release_child_resources(struct resource *r)
{
struct resource *tmp, *p;
resource_size_t size;
p = r->child;
r->child = NULL;
while (p) {
tmp = p;
p = p->sibling;
tmp->parent = NULL;
tmp->sibling = NULL;
__release_child_resources(tmp);
printk(KERN_DEBUG "release child resource %pR\n", tmp);
/* need to restore size, and keep flags */
size = resource_size(tmp);
tmp->start = 0;
tmp->end = size - 1;
}
}
void release_child_resources(struct resource *r)
{
write_lock(&resource_lock);
__release_child_resources(r);
write_unlock(&resource_lock);
}
/**
* request_resource_conflict - request and reserve an I/O or memory resource
* @root: root resource descriptor
* @new: resource descriptor desired by caller
*
* Returns 0 for success, conflict resource on error.
*/
struct resource *request_resource_conflict(struct resource *root, struct resource *new)
{
struct resource *conflict;
write_lock(&resource_lock);
conflict = __request_resource(root, new);
write_unlock(&resource_lock);
return conflict;
}
/**
* request_resource - request and reserve an I/O or memory resource
* @root: root resource descriptor
* @new: resource descriptor desired by caller
*
* Returns 0 for success, negative error code on error.
*/
int request_resource(struct resource *root, struct resource *new)
{
struct resource *conflict;
conflict = request_resource_conflict(root, new);
return conflict ? -EBUSY : 0;
}
EXPORT_SYMBOL(request_resource);
/**
* release_resource - release a previously reserved resource
* @old: resource pointer
*/
int release_resource(struct resource *old)
{
int retval;
write_lock(&resource_lock);
retval = __release_resource(old, true);
write_unlock(&resource_lock);
return retval;
}
EXPORT_SYMBOL(release_resource);
/**
* find_next_iomem_res - Finds the lowest iomem resource that covers part of
* [@start..@end].
*
* If a resource is found, returns 0 and @*res is overwritten with the part
* of the resource that's within [@start..@end]; if none is found, returns
* -ENODEV. Returns -EINVAL for invalid parameters.
*
* @start: start address of the resource searched for
* @end: end address of same resource
* @flags: flags which the resource must have
* @desc: descriptor the resource must have
* @res: return ptr, if resource found
*
* The caller must specify @start, @end, @flags, and @desc
* (which may be IORES_DESC_NONE).
*/
static int find_next_iomem_res(resource_size_t start, resource_size_t end,
unsigned long flags, unsigned long desc,
struct resource *res)
{
struct resource *p;
if (!res)
return -EINVAL;
if (start >= end)
return -EINVAL;
read_lock(&resource_lock);
for_each_resource(&iomem_resource, p, false) {
/* If we passed the resource we are looking for, stop */
if (p->start > end) {
p = NULL;
break;
}
/* Skip until we find a range that matches what we look for */
if (p->end < start)
continue;
if ((p->flags & flags) != flags)
continue;
if ((desc != IORES_DESC_NONE) && (desc != p->desc))
continue;
/* Found a match, break */
break;
}
if (p) {
/* copy data */
*res = (struct resource) {
.start = max(start, p->start),
.end = min(end, p->end),
.flags = p->flags,
.desc = p->desc,
.parent = p->parent,
};
}
read_unlock(&resource_lock);
return p ? 0 : -ENODEV;
}
static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end,
unsigned long flags, unsigned long desc,
void *arg,
int (*func)(struct resource *, void *))
{
struct resource res;
int ret = -EINVAL;
while (start < end &&
!find_next_iomem_res(start, end, flags, desc, &res)) {
ret = (*func)(&res, arg);
if (ret)
break;
start = res.end + 1;
}
return ret;
}
/**
* walk_iomem_res_desc - Walks through iomem resources and calls func()
* with matching resource ranges.
* *
* @desc: I/O resource descriptor. Use IORES_DESC_NONE to skip @desc check.
* @flags: I/O resource flags
* @start: start addr
* @end: end addr
* @arg: function argument for the callback @func
* @func: callback function that is called for each qualifying resource area
*
* All the memory ranges which overlap start,end and also match flags and
* desc are valid candidates.
*
* NOTE: For a new descriptor search, define a new IORES_DESC in
* <linux/ioport.h> and set it in 'desc' of a target resource entry.
*/
int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start,
u64 end, void *arg, int (*func)(struct resource *, void *))
{
return __walk_iomem_res_desc(start, end, flags, desc, arg, func);
}
EXPORT_SYMBOL_GPL(walk_iomem_res_desc);
/*
* This function calls the @func callback against all memory ranges of type
* System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
* Now, this function is only for System RAM, it deals with full ranges and
* not PFNs. If resources are not PFN-aligned, dealing with PFNs can truncate
* ranges.
*/
int walk_system_ram_res(u64 start, u64 end, void *arg,
int (*func)(struct resource *, void *))
{
unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, arg,
func);
}
/*
* This function, 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].start = res.start;
rams[i++].end = res.end;
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)
{
resource_size_t ostart, oend;
int type = 0; int other = 0;
struct resource *p, *dp;
bool is_type, covered;
struct resource res;
res.start = start;
res.end = start + size - 1;
for (p = parent->child; p ; p = p->sibling) {
if (!resource_overlaps(p, &res))
continue;
is_type = (p->flags & flags) == flags &&
(desc == IORES_DESC_NONE || desc == p->desc);
if (is_type) {
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;
ostart = max(res.start, p->start);
oend = min(res.end, p->end);
for_each_resource(p, dp, false) {
if (!resource_overlaps(dp, &res))
continue;
is_type = (dp->flags & flags) == flags &&
(desc == IORES_DESC_NONE || desc == dp->desc);
if (is_type) {
type++;
/*
* Range from 'ostart' to 'dp->start'
* isn't covered by matched resource.
*/
if (dp->start > ostart)
break;
if (dp->end >= oend) {
covered = true;
break;
}
/* Remove covered range */
ostart = max(ostart, 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);
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 tmp = *new, avail, alloc;
resource_alignf alignf = constraint->alignf;
tmp.start = root->start;
/*
* Skip past an allocated resource that starts at 0, since the assignment
* of this->start - 1 to tmp->end below would cause an underflow.
*/
if (this && this->start == root->start) {
tmp.start = (this == old) ? old->start : this->end + 1;
this = this->sibling;
}
for(;;) {
if (this)
tmp.end = (this == old) ? this->end : this->start - 1;
else
tmp.end = root->end;
if (tmp.end < tmp.start)
goto next;
resource_clip(&tmp, constraint->min, constraint->max);
arch_remove_reservations(&tmp);
/* Check for overflow after ALIGN() */
avail.start = ALIGN(tmp.start, constraint->align);
avail.end = tmp.end;
avail.flags = new->flags & ~IORESOURCE_UNSET;
if (avail.start >= tmp.start) {
alloc.flags = avail.flags;
if (alignf) {
alloc.start = alignf(constraint->alignf_data,
&avail, size, constraint->align);
} else {
alloc.start = avail.start;
}
alloc.end = alloc.start + size - 1;
if (alloc.start <= alloc.end &&
resource_contains(&avail, &alloc)) {
new->start = alloc.start;
new->end = alloc.end;
return 0;
}
}
next: if (!this || this->end == root->end)
break;
if (this != old)
tmp.start = this->end + 1;
this = this->sibling;
}
return -EBUSY;
}
/**
* find_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 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_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 __init
reserve_region_with_split(struct resource *root, resource_size_t start,
resource_size_t end, const char *name)
{
int abort = 0;
write_lock(&resource_lock);
if (root->start > start || root->end < end) {
pr_err("requested range [0x%llx-0x%llx] not in root %pr\n",
(unsigned long long)start, (unsigned long long)end,
root);
if (start > root->end || end < root->start)
abort = 1;
else {
if (end > root->end)
end = root->end;
if (start < root->start)
start = root->start;
pr_err("fixing request to [0x%llx-0x%llx]\n",
(unsigned long long)start,
(unsigned long long)end);
}
dump_stack();
}
if (!abort)
__reserve_region_with_split(root, start, end, name);
write_unlock(&resource_lock);
}
/**
* resource_alignment - calculate resource's alignment
* @res: resource pointer
*
* Returns alignment on success, 0 (invalid alignment) on failure.
*/
resource_size_t resource_alignment(struct resource *res)
{
switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
case IORESOURCE_SIZEALIGN:
return resource_size(res);
case IORESOURCE_STARTALIGN:
return res->start;
default:
return 0;
}
}
/*
* This is compatibility stuff for IO resources.
*
* Note how this, unlike the above, knows about
* the IO flag meanings (busy etc).
*
* request_region creates a new busy region.
*
* release_region releases a matching busy region.
*/
static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait);
static struct inode *iomem_inode;
#ifdef CONFIG_IO_STRICT_DEVMEM
static void revoke_iomem(struct resource *res)
{
/* pairs with smp_store_release() in iomem_init_inode() */
struct inode *inode = smp_load_acquire(&iomem_inode);
/*
* Check that the initialization has completed. Losing the race
* is ok because it means drivers are claiming resources before
* the fs_initcall level of init and prevent iomem_get_mapping users
* from establishing mappings.
*/
if (!inode)
return;
/*
* The expectation is that the driver has successfully marked
* the resource busy by this point, so devmem_is_allowed()
* should start returning false, however for performance this
* does not iterate the entire resource range.
*/
if (devmem_is_allowed(PHYS_PFN(res->start)) &&
devmem_is_allowed(PHYS_PFN(res->end))) {
/*
* *cringe* iomem=relaxed says "go ahead, what's the
* worst that can happen?"
*/
return;
}
unmap_mapping_range(inode->i_mapping, res->start, resource_size(res), 1);
}
#else
static void revoke_iomem(struct resource *res) {}
#endif
struct address_space *iomem_get_mapping(void)
{
/*
* This function is only called from file open paths, hence guaranteed
* that fs_initcalls have completed and no need to check for NULL. But
* since revoke_iomem can be called before the initcall we still need
* the barrier to appease checkers.
*/
return smp_load_acquire(&iomem_inode)->i_mapping;
}
static int __request_region_locked(struct resource *res, struct resource *parent,
resource_size_t start, resource_size_t n,
const char *name, int flags)
{
DECLARE_WAITQUEUE(wait, current);
res->name = name;
res->start = start;
res->end = start + n - 1;
for (;;) {
struct resource *conflict;
res->flags = resource_type(parent) | resource_ext_type(parent);
res->flags |= IORESOURCE_BUSY | flags;
res->desc = parent->desc;
conflict = __request_resource(parent, res);
if (!conflict)
break;
/*
* mm/hmm.c reserves physical addresses which then
* become unavailable to other users. Conflicts are
* not expected. Warn to aid debugging if encountered.
*/
if (conflict->desc == IORES_DESC_DEVICE_PRIVATE_MEMORY) {
pr_warn("Unaddressable device %s %pR conflicts with %pR",
conflict->name, conflict, res);
}
if (conflict != parent) {
if (!(conflict->flags & IORESOURCE_BUSY)) {
parent = conflict;
continue;
}
}
if (conflict->flags & flags & IORESOURCE_MUXED) {
add_wait_queue(&muxed_resource_wait, &wait);
write_unlock(&resource_lock);
set_current_state(TASK_UNINTERRUPTIBLE);
schedule();
remove_wait_queue(&muxed_resource_wait, &wait);
write_lock(&resource_lock);
continue;
}
/* Uhhuh, that didn't work out.. */
return -EBUSY;
}
return 0;
}
/**
* __request_region - create a new busy resource region
* @parent: parent resource descriptor
* @start: resource start address
* @n: resource region size
* @name: reserving caller's ID string
* @flags: IO resource flags
*/
struct resource *__request_region(struct resource *parent,
resource_size_t start, resource_size_t n,
const char *name, int flags)
{
struct resource *res = alloc_resource(GFP_KERNEL);
int ret;
if (!res)
return NULL;
write_lock(&resource_lock);
ret = __request_region_locked(res, parent, start, n, name, flags);
write_unlock(&resource_lock);
if (ret) {
free_resource(res);
return NULL;
}
if (parent == &iomem_resource)
revoke_iomem(res);
return res;
}
EXPORT_SYMBOL(__request_region);
/**
* __release_region - release a previously reserved resource region
* @parent: parent resource descriptor
* @start: resource start address
* @n: resource region size
*
* The described resource region must match a currently busy region.
*/
void __release_region(struct resource *parent, resource_size_t start,
resource_size_t n)
{
struct resource **p;
resource_size_t end;
p = &parent->child;
end = start + n - 1;
write_lock(&resource_lock);
for (;;) {
struct resource *res = *p;
if (!res)
break;
if (res->start <= start && res->end >= end) {
if (!(res->flags & IORESOURCE_BUSY)) {
p = &res->child;
continue;
}
if (res->start != start || res->end != end)
break;
*p = res->sibling;
write_unlock(&resource_lock);
if (res->flags & IORESOURCE_MUXED)
wake_up(&muxed_resource_wait);
free_resource(res);
return;
}
p = &res->sibling;
}
write_unlock(&resource_lock);
pr_warn("Trying to free nonexistent resource <%pa-%pa>\n", &start, &end);
}
EXPORT_SYMBOL(__release_region);
#ifdef CONFIG_MEMORY_HOTREMOVE
/**
* release_mem_region_adjustable - release a previously reserved memory region
* @start: resource start address
* @size: resource region size
*
* This interface is intended for memory hot-delete. The requested region
* is released from a currently busy memory resource. The requested region
* must either match exactly or fit into a single busy resource entry. In
* the latter case, the remaining resource is adjusted accordingly.
* Existing children of the busy memory resource must be immutable in the
* request.
*
* Note:
* - Additional release conditions, such as overlapping region, can be
* supported after they are confirmed as valid cases.
* - When a busy memory resource gets split into two entries, the code
* assumes that all children remain in the lower address entry for
* simplicity. Enhance this logic when necessary.
*/
void release_mem_region_adjustable(resource_size_t start, resource_size_t size)
{
struct resource *parent = &iomem_resource;
struct resource *new_res = NULL;
bool alloc_nofail = false;
struct resource **p;
struct resource *res;
resource_size_t end;
end = start + size - 1;
if (WARN_ON_ONCE((start < parent->start) || (end > parent->end)))
return;
/*
* We free up quite a lot of memory on memory hotunplug (esp., memap),
* just before releasing the region. This is highly unlikely to
* fail - let's play save and make it never fail as the caller cannot
* perform any error handling (e.g., trying to re-add memory will fail
* similarly).
*/
retry:
new_res = alloc_resource(GFP_KERNEL | (alloc_nofail ? __GFP_NOFAIL : 0));
p = &parent->child;
write_lock(&resource_lock);
while ((res = *p)) {
if (res->start >= end)
break;
/* look for the next resource if it does not fit into */
if (res->start > start || res->end < end) {
p = &res->sibling;
continue;
}
if (!(res->flags & IORESOURCE_MEM))
break;
if (!(res->flags & IORESOURCE_BUSY)) {
p = &res->child;
continue;
}
/* found the target resource; let's adjust accordingly */
if (res->start == start && res->end == end) {
/* free the whole entry */
*p = res->sibling;
free_resource(res);
} else if (res->start == start && res->end != end) {
/* adjust the start */
WARN_ON_ONCE(__adjust_resource(res, end + 1,
res->end - end));
} else if (res->start != start && res->end == end) {
/* adjust the end */
WARN_ON_ONCE(__adjust_resource(res, res->start,
start - res->start));
} else {
/* split into two entries - we need a new resource */
if (!new_res) {
new_res = alloc_resource(GFP_ATOMIC);
if (!new_res) {
alloc_nofail = true;
write_unlock(&resource_lock);
goto retry;
}
}
new_res->name = res->name;
new_res->start = end + 1;
new_res->end = res->end;
new_res->flags = res->flags;
new_res->desc = res->desc;
new_res->parent = res->parent;
new_res->sibling = res->sibling;
new_res->child = NULL;
if (WARN_ON_ONCE(__adjust_resource(res, res->start,
start - res->start)))
break;
res->sibling = new_res;
new_res = NULL;
}
break;
}
write_unlock(&resource_lock);
free_resource(new_res);
}
#endif /* CONFIG_MEMORY_HOTREMOVE */
#ifdef CONFIG_MEMORY_HOTPLUG
static bool system_ram_resources_mergeable(struct resource *r1,
struct resource *r2)
{
/* We assume either r1 or r2 is IORESOURCE_SYSRAM_MERGEABLE. */
return r1->flags == r2->flags && r1->end + 1 == r2->start &&
r1->name == r2->name && r1->desc == r2->desc &&
!r1->child && !r2->child;
}
/**
* merge_system_ram_resource - mark the System RAM resource mergeable and try to
* merge it with adjacent, mergeable resources
* @res: resource descriptor
*
* This interface is intended for memory hotplug, whereby lots of contiguous
* system ram resources are added (e.g., via add_memory*()) by a driver, and
* the actual resource boundaries are not of interest (e.g., it might be
* relevant for DIMMs). Only resources that are marked mergeable, that have the
* same parent, and that don't have any children are considered. All mergeable
* resources must be immutable during the request.
*
* Note:
* - The caller has to make sure that no pointers to resources that are
* marked mergeable are used anymore after this call - the resource might
* be freed and the pointer might be stale!
* - release_mem_region_adjustable() will split on demand on memory hotunplug
*/
void merge_system_ram_resource(struct resource *res)
{
const unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
struct resource *cur;
if (WARN_ON_ONCE((res->flags & flags) != flags))
return;
write_lock(&resource_lock);
res->flags |= IORESOURCE_SYSRAM_MERGEABLE;
/* Try to merge with next item in the list. */
cur = res->sibling;
if (cur && system_ram_resources_mergeable(res, cur)) {
res->end = cur->end;
res->sibling = cur->sibling;
free_resource(cur);
}
/* Try to merge with previous item in the list. */
cur = res->parent->child;
while (cur && cur->sibling != res)
cur = cur->sibling;
if (cur && system_ram_resources_mergeable(cur, res)) {
cur->end = res->end;
cur->sibling = res->sibling;
free_resource(res);
}
write_unlock(&resource_lock);
}
#endif /* CONFIG_MEMORY_HOTPLUG */
/*
* Managed region resource
*/
static void devm_resource_release(struct device *dev, void *ptr)
{
struct resource **r = ptr;
release_resource(*r);
}
/**
* devm_request_resource() - request and reserve an I/O or memory resource
* @dev: device for which to request the resource
* @root: root of the resource tree from which to request the resource
* @new: descriptor of the resource to request
*
* This is a device-managed version of request_resource(). There is usually
* no need to release resources requested by this function explicitly since
* that will be taken care of when the device is unbound from its driver.
* If for some reason the resource needs to be released explicitly, because
* of ordering issues for example, drivers must call devm_release_resource()
* rather than the regular release_resource().
*
* When a conflict is detected between any existing resources and the newly
* requested resource, an error message will be printed.
*
* Returns 0 on success or a negative error code on failure.
*/
int devm_request_resource(struct device *dev, struct resource *root,
struct resource *new)
{
struct resource *conflict, **ptr;
ptr = devres_alloc(devm_resource_release, sizeof(*ptr), GFP_KERNEL);
if (!ptr)
return -ENOMEM;
*ptr = new;
conflict = request_resource_conflict(root, new);
if (conflict) {
dev_err(dev, "resource collision: %pR conflicts with %s %pR\n",
new, conflict->name, conflict);
devres_free(ptr);
return -EBUSY;
}
devres_add(dev, ptr);
return 0;
}
EXPORT_SYMBOL(devm_request_resource);
static int devm_resource_match(struct device *dev, void *res, void *data)
{
struct resource **ptr = res;
return *ptr == data;
}
/**
* devm_release_resource() - release a previously requested resource
* @dev: device for which to release the resource
* @new: descriptor of the resource to release
*
* Releases a resource previously requested using devm_request_resource().
*/
void devm_release_resource(struct device *dev, struct resource *new)
{
WARN_ON(devres_release(dev, devm_resource_release, devm_resource_match,
new));
}
EXPORT_SYMBOL(devm_release_resource);
struct region_devres {
struct resource *parent;
resource_size_t start;
resource_size_t n;
};
static void devm_region_release(struct device *dev, void *res)
{
struct region_devres *this = res;
__release_region(this->parent, this->start, this->n);
}
static int devm_region_match(struct device *dev, void *res, void *match_data)
{
struct region_devres *this = res, *match = match_data;
return this->parent == match->parent &&
this->start == match->start && this->n == match->n;
}
struct resource *
__devm_request_region(struct device *dev, struct resource *parent,
resource_size_t start, resource_size_t n, const char *name)
{
struct region_devres *dr = NULL;
struct resource *res;
dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
GFP_KERNEL);
if (!dr)
return NULL;
dr->parent = parent;
dr->start = start;
dr->n = n;
res = __request_region(parent, start, n, name, 0);
if (res)
devres_add(dev, dr);
else
devres_free(dr);
return res;
}
EXPORT_SYMBOL(__devm_request_region);
void __devm_release_region(struct device *dev, struct resource *parent,
resource_size_t start, resource_size_t n)
{
struct region_devres match_data = { parent, start, n };
__release_region(parent, start, n);
WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
&match_data));
}
EXPORT_SYMBOL(__devm_release_region);
/*
* Reserve I/O ports or memory based on "reserve=" kernel parameter.
*/
#define MAXRESERVE 4
static int __init reserve_setup(char *str)
{
static int reserved;
static struct resource reserve[MAXRESERVE];
for (;;) {
unsigned int io_start, io_num;
int x = reserved;
struct resource *parent;
if (get_option(&str, &io_start) != 2)
break;
if (get_option(&str, &io_num) == 0)
break;
if (x < MAXRESERVE) {
struct resource *res = reserve + x;
/*
* If the region starts below 0x10000, we assume it's
* I/O port space; otherwise assume it's memory.
*/
if (io_start < 0x10000) {
res->flags = IORESOURCE_IO;
parent = &ioport_resource;
} else {
res->flags = IORESOURCE_MEM;
parent = &iomem_resource;
}
res->name = "reserved";
res->start = io_start;
res->end = io_start + io_num - 1;
res->flags |= IORESOURCE_BUSY;
res->desc = IORES_DESC_NONE;
res->child = NULL;
if (request_resource(parent, res) == 0)
reserved = x+1;
}
}
return 1;
}
__setup("reserve=", reserve_setup);
/*
* Check if the requested addr and size spans more than any slot in the
* iomem resource tree.
*/
int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
{
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_DEVMEM
static int strict_iomem_checks = 1;
#else
static int strict_iomem_checks;
#endif
/*
* Check if an address is exclusive to the kernel and must not be mapped to
* user space, for example, via /dev/mem.
*
* Returns true if exclusive to the kernel, otherwise returns false.
*/
bool resource_is_exclusive(struct resource *root, u64 addr, resource_size_t size)
{
const unsigned int exclusive_system_ram = IORESOURCE_SYSTEM_RAM |
IORESOURCE_EXCLUSIVE;
bool skip_children = false, err = false;
struct resource *p;
read_lock(&resource_lock);
for_each_resource(root, p, skip_children) {
if (p->start >= addr + size)
break;
if (p->end < addr) {
skip_children = true;
continue;
}
skip_children = false;
/*
* IORESOURCE_SYSTEM_RAM resources are exclusive if
* IORESOURCE_EXCLUSIVE is set, even if they
* are not busy and even if "iomem=relaxed" is set. The
* responsible driver dynamically adds/removes system RAM within
* such an area and uncontrolled access is dangerous.
*/
if ((p->flags & exclusive_system_ram) == exclusive_system_ram) {
err = true;
break;
}
/*
* A resource is exclusive if IORESOURCE_EXCLUSIVE is set
* or CONFIG_IO_STRICT_DEVMEM is enabled and the
* resource is busy.
*/
if (!strict_iomem_checks || !(p->flags & IORESOURCE_BUSY))
continue;
if (IS_ENABLED(CONFIG_IO_STRICT_DEVMEM)
|| p->flags & IORESOURCE_EXCLUSIVE) {
err = true;
break;
}
}
read_unlock(&resource_lock);
return err;
}
bool iomem_is_exclusive(u64 addr)
{
return resource_is_exclusive(&iomem_resource, addr & PAGE_MASK,
PAGE_SIZE);
}
struct resource_entry *resource_list_create_entry(struct resource *res,
size_t extra_size)
{
struct resource_entry *entry;
entry = kzalloc(sizeof(*entry) + extra_size, GFP_KERNEL);
if (entry) {
INIT_LIST_HEAD(&entry->node);
entry->res = res ? res : &entry->__res;
}
return entry;
}
EXPORT_SYMBOL(resource_list_create_entry);
void resource_list_free(struct list_head *head)
{
struct resource_entry *entry, *tmp;
list_for_each_entry_safe(entry, tmp, head, node)
resource_list_destroy_entry(entry);
}
EXPORT_SYMBOL(resource_list_free);
#ifdef CONFIG_GET_FREE_REGION
#define GFR_DESCENDING (1UL << 0)
#define GFR_REQUEST_REGION (1UL << 1)
#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, 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, 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->start = addr;
res->end = addr + size - 1;
res->name = name;
res->desc = desc;
res->flags = IORESOURCE_MEM;
/*
* Only succeed if the resource hosts an exclusive
* range after the insert
*/
if (__insert_resource(base, res) || res->child)
break;
write_unlock(&resource_lock);
}
return res;
}
write_unlock(&resource_lock);
if (flags & GFR_REQUEST_REGION) {
free_resource(res);
devres_free(dr);
} else if (dev)
devm_release_action(dev, remove_free_mem_region, res);
return ERR_PTR(-ERANGE);
}
/**
* devm_request_free_mem_region - find free region for device private memory
*
* @dev: device struct to bind the resource to
* @size: size in bytes of the device memory to add
* @base: resource tree to look in
*
* This function tries to find an empty range of physical address big enough to
* contain the new resource, so that it can later be hotplugged as ZONE_DEVICE
* memory, which in turn allocates struct pages.
*/
struct resource *devm_request_free_mem_region(struct device *dev,
struct resource *base, unsigned long size)
{
unsigned long flags = GFR_DESCENDING | GFR_REQUEST_REGION;
return get_free_mem_region(dev, base, size, GFR_DEFAULT_ALIGN,
dev_name(dev),
IORES_DESC_DEVICE_PRIVATE_MEMORY, flags);
}
EXPORT_SYMBOL_GPL(devm_request_free_mem_region);
struct resource *request_free_mem_region(struct resource *base,
unsigned long size, const char *name)
{
unsigned long flags = GFR_DESCENDING | GFR_REQUEST_REGION;
return get_free_mem_region(NULL, base, size, GFR_DEFAULT_ALIGN, name,
IORES_DESC_DEVICE_PRIVATE_MEMORY, flags);
}
EXPORT_SYMBOL_GPL(request_free_mem_region);
/**
* alloc_free_mem_region - find a free region relative to @base
* @base: resource that will parent the new resource
* @size: size in bytes of memory to allocate from @base
* @align: alignment requirements for the allocation
* @name: resource name
*
* Buses like CXL, that can dynamically instantiate new memory regions,
* need a method to allocate physical address space for those regions.
* Allocate and insert a new resource to cover a free, unclaimed by a
* descendant of @base, range in the span of @base.
*/
struct resource *alloc_free_mem_region(struct resource *base,
unsigned long size, unsigned long align,
const char *name)
{
/* Default of ascending direction and insert resource */
unsigned long flags = 0;
return get_free_mem_region(NULL, base, size, align, name,
IORES_DESC_NONE, flags);
}
EXPORT_SYMBOL_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);
Codebase Browser
linux