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![Dan Williams](/assets/img/avatar_default.png)
The core of devm_request_free_mem_region() is a helper that searches for free space in iomem_resource and performs __request_region_locked() on the result of that search. The policy choices of the implementation conform to what CONFIG_DEVICE_PRIVATE users want which is memory that is immediately marked busy, and a preference to search for the first-fit free range in descending order from the top of the physical address space. CXL has a need for a similar allocator, but with the following tweaks: 1/ Search for free space in ascending order 2/ Search for free space relative to a given CXL window 3/ 'insert' rather than 'request' the new resource given downstream drivers from the CXL Region driver (like the pmem or dax drivers) are responsible for request_mem_region() when they activate the memory range. Rework __request_free_mem_region() into get_free_mem_region() which takes a set of GFR_* (Get Free Region) flags to control the allocation policy (ascending vs descending), and "busy" policy (insert_resource() vs request_region()). As part of the consolidation of the legacy GFR_REQUEST_REGION case with the new default of just inserting a new resource into the free space some minor cleanups like not checking for NULL before calling devres_free() (which does its own check) is included. Suggested-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/linux-cxl/20220420143406.GY2120790@nvidia.com/ Cc: Matthew Wilcox <willy@infradead.org> Cc: Christoph Hellwig <hch@lst.de> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/165784333333.1758207.13703329337805274043.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2031 lines
52 KiB
C
2031 lines
52 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* linux/kernel/resource.c
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*
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* Copyright (C) 1999 Linus Torvalds
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* Copyright (C) 1999 Martin Mares <mj@ucw.cz>
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*
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* Arbitrary resource management.
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/export.h>
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#include <linux/errno.h>
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#include <linux/ioport.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/spinlock.h>
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#include <linux/fs.h>
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#include <linux/proc_fs.h>
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#include <linux/pseudo_fs.h>
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#include <linux/sched.h>
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#include <linux/seq_file.h>
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#include <linux/device.h>
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#include <linux/pfn.h>
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#include <linux/mm.h>
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#include <linux/mount.h>
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#include <linux/resource_ext.h>
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#include <uapi/linux/magic.h>
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#include <asm/io.h>
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struct resource ioport_resource = {
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.name = "PCI IO",
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.start = 0,
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.end = IO_SPACE_LIMIT,
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.flags = IORESOURCE_IO,
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};
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EXPORT_SYMBOL(ioport_resource);
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struct resource iomem_resource = {
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.name = "PCI mem",
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.start = 0,
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.end = -1,
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.flags = IORESOURCE_MEM,
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};
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EXPORT_SYMBOL(iomem_resource);
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/* constraints to be met while allocating resources */
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struct resource_constraint {
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resource_size_t min, max, align;
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resource_size_t (*alignf)(void *, const struct resource *,
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resource_size_t, resource_size_t);
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void *alignf_data;
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};
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static DEFINE_RWLOCK(resource_lock);
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static struct resource *next_resource(struct resource *p)
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{
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if (p->child)
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return p->child;
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while (!p->sibling && p->parent)
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p = p->parent;
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return p->sibling;
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}
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static struct resource *next_resource_skip_children(struct resource *p)
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{
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while (!p->sibling && p->parent)
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p = p->parent;
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return p->sibling;
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}
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#define for_each_resource(_root, _p, _skip_children) \
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for ((_p) = (_root)->child; (_p); \
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(_p) = (_skip_children) ? next_resource_skip_children(_p) : \
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next_resource(_p))
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static void *r_next(struct seq_file *m, void *v, loff_t *pos)
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{
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struct resource *p = v;
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(*pos)++;
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return (void *)next_resource(p);
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}
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#ifdef CONFIG_PROC_FS
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enum { MAX_IORES_LEVEL = 5 };
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static void *r_start(struct seq_file *m, loff_t *pos)
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__acquires(resource_lock)
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{
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struct resource *p = pde_data(file_inode(m->file));
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loff_t l = 0;
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read_lock(&resource_lock);
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for (p = p->child; p && l < *pos; p = r_next(m, p, &l))
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;
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return p;
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}
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static void r_stop(struct seq_file *m, void *v)
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__releases(resource_lock)
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{
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read_unlock(&resource_lock);
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}
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static int r_show(struct seq_file *m, void *v)
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{
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struct resource *root = pde_data(file_inode(m->file));
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struct resource *r = v, *p;
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unsigned long long start, end;
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int width = root->end < 0x10000 ? 4 : 8;
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int depth;
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for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent)
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if (p->parent == root)
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break;
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if (file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN)) {
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start = r->start;
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end = r->end;
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} else {
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start = end = 0;
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}
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seq_printf(m, "%*s%0*llx-%0*llx : %s\n",
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depth * 2, "",
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width, start,
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width, end,
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r->name ? r->name : "<BAD>");
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return 0;
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}
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static const struct seq_operations resource_op = {
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.start = r_start,
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.next = r_next,
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.stop = r_stop,
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.show = r_show,
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};
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static int __init ioresources_init(void)
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{
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proc_create_seq_data("ioports", 0, NULL, &resource_op,
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&ioport_resource);
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proc_create_seq_data("iomem", 0, NULL, &resource_op, &iomem_resource);
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return 0;
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}
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__initcall(ioresources_init);
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#endif /* CONFIG_PROC_FS */
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static void free_resource(struct resource *res)
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{
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/**
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* If the resource was allocated using memblock early during boot
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* we'll leak it here: we can only return full pages back to the
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* buddy and trying to be smart and reusing them eventually in
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* alloc_resource() overcomplicates resource handling.
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*/
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if (res && PageSlab(virt_to_head_page(res)))
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kfree(res);
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}
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static struct resource *alloc_resource(gfp_t flags)
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{
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return kzalloc(sizeof(struct resource), flags);
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}
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/* Return the conflict entry if you can't request it */
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static struct resource * __request_resource(struct resource *root, struct resource *new)
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{
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resource_size_t start = new->start;
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resource_size_t end = new->end;
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struct resource *tmp, **p;
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if (end < start)
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return root;
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if (start < root->start)
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return root;
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if (end > root->end)
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return root;
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p = &root->child;
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for (;;) {
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tmp = *p;
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if (!tmp || tmp->start > end) {
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new->sibling = tmp;
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*p = new;
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new->parent = root;
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return NULL;
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}
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p = &tmp->sibling;
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if (tmp->end < start)
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continue;
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return tmp;
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}
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}
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static int __release_resource(struct resource *old, bool release_child)
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{
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struct resource *tmp, **p, *chd;
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p = &old->parent->child;
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for (;;) {
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tmp = *p;
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if (!tmp)
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break;
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if (tmp == old) {
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if (release_child || !(tmp->child)) {
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*p = tmp->sibling;
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} else {
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for (chd = tmp->child;; chd = chd->sibling) {
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chd->parent = tmp->parent;
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if (!(chd->sibling))
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break;
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}
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*p = tmp->child;
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chd->sibling = tmp->sibling;
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}
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old->parent = NULL;
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return 0;
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}
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p = &tmp->sibling;
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}
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return -EINVAL;
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}
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static void __release_child_resources(struct resource *r)
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{
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struct resource *tmp, *p;
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resource_size_t size;
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p = r->child;
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r->child = NULL;
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while (p) {
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tmp = p;
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p = p->sibling;
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tmp->parent = NULL;
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tmp->sibling = NULL;
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__release_child_resources(tmp);
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printk(KERN_DEBUG "release child resource %pR\n", tmp);
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/* need to restore size, and keep flags */
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size = resource_size(tmp);
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tmp->start = 0;
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tmp->end = size - 1;
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}
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}
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void release_child_resources(struct resource *r)
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{
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write_lock(&resource_lock);
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__release_child_resources(r);
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write_unlock(&resource_lock);
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}
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/**
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* request_resource_conflict - request and reserve an I/O or memory resource
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* @root: root resource descriptor
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* @new: resource descriptor desired by caller
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*
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* Returns 0 for success, conflict resource on error.
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*/
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struct resource *request_resource_conflict(struct resource *root, struct resource *new)
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{
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struct resource *conflict;
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write_lock(&resource_lock);
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conflict = __request_resource(root, new);
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write_unlock(&resource_lock);
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return conflict;
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}
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/**
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* request_resource - request and reserve an I/O or memory resource
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* @root: root resource descriptor
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* @new: resource descriptor desired by caller
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*
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* Returns 0 for success, negative error code on error.
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*/
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int request_resource(struct resource *root, struct resource *new)
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{
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struct resource *conflict;
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conflict = request_resource_conflict(root, new);
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return conflict ? -EBUSY : 0;
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}
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EXPORT_SYMBOL(request_resource);
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/**
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* release_resource - release a previously reserved resource
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* @old: resource pointer
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*/
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int release_resource(struct resource *old)
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{
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int retval;
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write_lock(&resource_lock);
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retval = __release_resource(old, true);
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write_unlock(&resource_lock);
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return retval;
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}
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EXPORT_SYMBOL(release_resource);
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/**
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* find_next_iomem_res - Finds the lowest iomem resource that covers part of
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* [@start..@end].
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*
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* If a resource is found, returns 0 and @*res is overwritten with the part
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* of the resource that's within [@start..@end]; if none is found, returns
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* -ENODEV. Returns -EINVAL for invalid parameters.
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*
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* @start: start address of the resource searched for
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* @end: end address of same resource
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* @flags: flags which the resource must have
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* @desc: descriptor the resource must have
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* @res: return ptr, if resource found
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*
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* The caller must specify @start, @end, @flags, and @desc
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* (which may be IORES_DESC_NONE).
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*/
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static int find_next_iomem_res(resource_size_t start, resource_size_t end,
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unsigned long flags, unsigned long desc,
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struct resource *res)
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{
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struct resource *p;
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if (!res)
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return -EINVAL;
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if (start >= end)
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return -EINVAL;
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read_lock(&resource_lock);
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for (p = iomem_resource.child; p; p = next_resource(p)) {
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/* If we passed the resource we are looking for, stop */
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if (p->start > end) {
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p = NULL;
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break;
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}
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/* Skip until we find a range that matches what we look for */
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if (p->end < start)
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continue;
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if ((p->flags & flags) != flags)
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continue;
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if ((desc != IORES_DESC_NONE) && (desc != p->desc))
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continue;
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/* Found a match, break */
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break;
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}
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if (p) {
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/* copy data */
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*res = (struct resource) {
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.start = max(start, p->start),
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.end = min(end, p->end),
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.flags = p->flags,
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.desc = p->desc,
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.parent = p->parent,
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};
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}
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read_unlock(&resource_lock);
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return p ? 0 : -ENODEV;
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}
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static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end,
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unsigned long flags, unsigned long desc,
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void *arg,
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int (*func)(struct resource *, void *))
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{
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struct resource res;
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int ret = -EINVAL;
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while (start < end &&
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!find_next_iomem_res(start, end, flags, desc, &res)) {
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ret = (*func)(&res, arg);
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if (ret)
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break;
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start = res.end + 1;
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}
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return ret;
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}
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/**
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* walk_iomem_res_desc - Walks through iomem resources and calls func()
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* with matching resource ranges.
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* *
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* @desc: I/O resource descriptor. Use IORES_DESC_NONE to skip @desc check.
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* @flags: I/O resource flags
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* @start: start addr
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* @end: end addr
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* @arg: function argument for the callback @func
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* @func: callback function that is called for each qualifying resource area
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*
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* All the memory ranges which overlap start,end and also match flags and
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* desc are valid candidates.
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*
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* NOTE: For a new descriptor search, define a new IORES_DESC in
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* <linux/ioport.h> and set it in 'desc' of a target resource entry.
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*/
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int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start,
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u64 end, void *arg, int (*func)(struct resource *, void *))
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{
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return __walk_iomem_res_desc(start, end, flags, desc, arg, func);
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}
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EXPORT_SYMBOL_GPL(walk_iomem_res_desc);
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/*
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* This function calls the @func callback against all memory ranges of type
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* System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
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* Now, this function is only for System RAM, it deals with full ranges and
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* not PFNs. If resources are not PFN-aligned, dealing with PFNs can truncate
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* ranges.
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*/
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int walk_system_ram_res(u64 start, u64 end, void *arg,
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int (*func)(struct resource *, void *))
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{
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unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
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return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, arg,
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func);
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}
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/*
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* This function calls the @func callback against all memory ranges, which
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* are ranges marked as IORESOURCE_MEM and IORESOUCE_BUSY.
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*/
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int walk_mem_res(u64 start, u64 end, void *arg,
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int (*func)(struct resource *, void *))
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{
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unsigned long flags = IORESOURCE_MEM | IORESOURCE_BUSY;
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return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, arg,
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func);
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}
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/*
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* This function calls the @func callback against all memory ranges of type
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* System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
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* It is to be used only for System RAM.
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*/
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int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
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void *arg, int (*func)(unsigned long, unsigned long, void *))
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{
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resource_size_t start, end;
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unsigned long flags;
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struct resource res;
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unsigned long pfn, end_pfn;
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int ret = -EINVAL;
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start = (u64) start_pfn << PAGE_SHIFT;
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end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
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flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
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while (start < end &&
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!find_next_iomem_res(start, end, flags, IORES_DESC_NONE, &res)) {
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pfn = PFN_UP(res.start);
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end_pfn = PFN_DOWN(res.end + 1);
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if (end_pfn > pfn)
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ret = (*func)(pfn, end_pfn - pfn, arg);
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if (ret)
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break;
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start = res.end + 1;
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}
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return ret;
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}
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static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg)
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{
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return 1;
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}
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/*
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* This generic page_is_ram() returns true if specified address is
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* registered as System RAM in iomem_resource list.
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*/
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int __weak page_is_ram(unsigned long pfn)
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{
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return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1;
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}
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EXPORT_SYMBOL_GPL(page_is_ram);
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static int __region_intersects(struct resource *parent, resource_size_t start,
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size_t size, unsigned long flags,
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unsigned long desc)
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{
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struct resource res;
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int type = 0; int other = 0;
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struct resource *p;
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res.start = start;
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res.end = start + size - 1;
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for (p = parent->child; p ; p = p->sibling) {
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bool is_type = (((p->flags & flags) == flags) &&
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((desc == IORES_DESC_NONE) ||
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(desc == p->desc)));
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if (resource_overlaps(p, &res))
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is_type ? type++ : other++;
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}
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if (type == 0)
|
|
return REGION_DISJOINT;
|
|
|
|
if (other == 0)
|
|
return REGION_INTERSECTS;
|
|
|
|
return REGION_MIXED;
|
|
}
|
|
|
|
/**
|
|
* region_intersects() - determine intersection of region with known resources
|
|
* @start: region start address
|
|
* @size: size of region
|
|
* @flags: flags of resource (in iomem_resource)
|
|
* @desc: descriptor of resource (in iomem_resource) or IORES_DESC_NONE
|
|
*
|
|
* Check if the specified region partially overlaps or fully eclipses a
|
|
* resource identified by @flags and @desc (optional with IORES_DESC_NONE).
|
|
* Return REGION_DISJOINT if the region does not overlap @flags/@desc,
|
|
* return REGION_MIXED if the region overlaps @flags/@desc and another
|
|
* resource, and return REGION_INTERSECTS if the region overlaps @flags/@desc
|
|
* and no other defined resource. Note that REGION_INTERSECTS is also
|
|
* returned in the case when the specified region overlaps RAM and undefined
|
|
* memory holes.
|
|
*
|
|
* region_intersect() is used by memory remapping functions to ensure
|
|
* the user is not remapping RAM and is a vast speed up over walking
|
|
* through the resource table page by page.
|
|
*/
|
|
int region_intersects(resource_size_t start, size_t size, unsigned long flags,
|
|
unsigned long desc)
|
|
{
|
|
int ret;
|
|
|
|
read_lock(&resource_lock);
|
|
ret = __region_intersects(&iomem_resource, start, size, flags, desc);
|
|
read_unlock(&resource_lock);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(region_intersects);
|
|
|
|
void __weak arch_remove_reservations(struct resource *avail)
|
|
{
|
|
}
|
|
|
|
static resource_size_t simple_align_resource(void *data,
|
|
const struct resource *avail,
|
|
resource_size_t size,
|
|
resource_size_t align)
|
|
{
|
|
return avail->start;
|
|
}
|
|
|
|
static void resource_clip(struct resource *res, resource_size_t min,
|
|
resource_size_t max)
|
|
{
|
|
if (res->start < min)
|
|
res->start = min;
|
|
if (res->end > max)
|
|
res->end = max;
|
|
}
|
|
|
|
/*
|
|
* Find empty slot in the resource tree with the given range and
|
|
* alignment constraints
|
|
*/
|
|
static int __find_resource(struct resource *root, struct resource *old,
|
|
struct resource *new,
|
|
resource_size_t size,
|
|
struct resource_constraint *constraint)
|
|
{
|
|
struct resource *this = root->child;
|
|
struct resource tmp = *new, avail, alloc;
|
|
|
|
tmp.start = root->start;
|
|
/*
|
|
* Skip past an allocated resource that starts at 0, since the assignment
|
|
* of this->start - 1 to tmp->end below would cause an underflow.
|
|
*/
|
|
if (this && this->start == root->start) {
|
|
tmp.start = (this == old) ? old->start : this->end + 1;
|
|
this = this->sibling;
|
|
}
|
|
for(;;) {
|
|
if (this)
|
|
tmp.end = (this == old) ? this->end : this->start - 1;
|
|
else
|
|
tmp.end = root->end;
|
|
|
|
if (tmp.end < tmp.start)
|
|
goto next;
|
|
|
|
resource_clip(&tmp, constraint->min, constraint->max);
|
|
arch_remove_reservations(&tmp);
|
|
|
|
/* Check for overflow after ALIGN() */
|
|
avail.start = ALIGN(tmp.start, constraint->align);
|
|
avail.end = tmp.end;
|
|
avail.flags = new->flags & ~IORESOURCE_UNSET;
|
|
if (avail.start >= tmp.start) {
|
|
alloc.flags = avail.flags;
|
|
alloc.start = constraint->alignf(constraint->alignf_data, &avail,
|
|
size, constraint->align);
|
|
alloc.end = alloc.start + size - 1;
|
|
if (alloc.start <= alloc.end &&
|
|
resource_contains(&avail, &alloc)) {
|
|
new->start = alloc.start;
|
|
new->end = alloc.end;
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
next: if (!this || this->end == root->end)
|
|
break;
|
|
|
|
if (this != old)
|
|
tmp.start = this->end + 1;
|
|
this = this->sibling;
|
|
}
|
|
return -EBUSY;
|
|
}
|
|
|
|
/*
|
|
* Find empty slot in the resource tree given range and alignment.
|
|
*/
|
|
static int find_resource(struct resource *root, struct resource *new,
|
|
resource_size_t size,
|
|
struct resource_constraint *constraint)
|
|
{
|
|
return __find_resource(root, NULL, new, size, constraint);
|
|
}
|
|
|
|
/**
|
|
* reallocate_resource - allocate a slot in the resource tree given range & alignment.
|
|
* The resource will be relocated if the new size cannot be reallocated in the
|
|
* current location.
|
|
*
|
|
* @root: root resource descriptor
|
|
* @old: resource descriptor desired by caller
|
|
* @newsize: new size of the resource descriptor
|
|
* @constraint: the size and alignment constraints to be met.
|
|
*/
|
|
static int reallocate_resource(struct resource *root, struct resource *old,
|
|
resource_size_t newsize,
|
|
struct resource_constraint *constraint)
|
|
{
|
|
int err=0;
|
|
struct resource new = *old;
|
|
struct resource *conflict;
|
|
|
|
write_lock(&resource_lock);
|
|
|
|
if ((err = __find_resource(root, old, &new, newsize, constraint)))
|
|
goto out;
|
|
|
|
if (resource_contains(&new, old)) {
|
|
old->start = new.start;
|
|
old->end = new.end;
|
|
goto out;
|
|
}
|
|
|
|
if (old->child) {
|
|
err = -EBUSY;
|
|
goto out;
|
|
}
|
|
|
|
if (resource_contains(old, &new)) {
|
|
old->start = new.start;
|
|
old->end = new.end;
|
|
} else {
|
|
__release_resource(old, true);
|
|
*old = new;
|
|
conflict = __request_resource(root, old);
|
|
BUG_ON(conflict);
|
|
}
|
|
out:
|
|
write_unlock(&resource_lock);
|
|
return err;
|
|
}
|
|
|
|
|
|
/**
|
|
* allocate_resource - allocate empty slot in the resource tree given range & alignment.
|
|
* The resource will be reallocated with a new size if it was already allocated
|
|
* @root: root resource descriptor
|
|
* @new: resource descriptor desired by caller
|
|
* @size: requested resource region size
|
|
* @min: minimum boundary to allocate
|
|
* @max: maximum boundary to allocate
|
|
* @align: alignment requested, in bytes
|
|
* @alignf: alignment function, optional, called if not NULL
|
|
* @alignf_data: arbitrary data to pass to the @alignf function
|
|
*/
|
|
int allocate_resource(struct resource *root, struct resource *new,
|
|
resource_size_t size, resource_size_t min,
|
|
resource_size_t max, resource_size_t align,
|
|
resource_size_t (*alignf)(void *,
|
|
const struct resource *,
|
|
resource_size_t,
|
|
resource_size_t),
|
|
void *alignf_data)
|
|
{
|
|
int err;
|
|
struct resource_constraint constraint;
|
|
|
|
if (!alignf)
|
|
alignf = simple_align_resource;
|
|
|
|
constraint.min = min;
|
|
constraint.max = max;
|
|
constraint.align = align;
|
|
constraint.alignf = alignf;
|
|
constraint.alignf_data = alignf_data;
|
|
|
|
if ( new->parent ) {
|
|
/* resource is already allocated, try reallocating with
|
|
the new constraints */
|
|
return reallocate_resource(root, new, size, &constraint);
|
|
}
|
|
|
|
write_lock(&resource_lock);
|
|
err = find_resource(root, new, size, &constraint);
|
|
if (err >= 0 && __request_resource(root, new))
|
|
err = -EBUSY;
|
|
write_unlock(&resource_lock);
|
|
return err;
|
|
}
|
|
|
|
EXPORT_SYMBOL(allocate_resource);
|
|
|
|
/**
|
|
* lookup_resource - find an existing resource by a resource start address
|
|
* @root: root resource descriptor
|
|
* @start: resource start address
|
|
*
|
|
* Returns a pointer to the resource if found, NULL otherwise
|
|
*/
|
|
struct resource *lookup_resource(struct resource *root, resource_size_t start)
|
|
{
|
|
struct resource *res;
|
|
|
|
read_lock(&resource_lock);
|
|
for (res = root->child; res; res = res->sibling) {
|
|
if (res->start == start)
|
|
break;
|
|
}
|
|
read_unlock(&resource_lock);
|
|
|
|
return res;
|
|
}
|
|
|
|
/*
|
|
* Insert a resource into the resource tree. If successful, return NULL,
|
|
* otherwise return the conflicting resource (compare to __request_resource())
|
|
*/
|
|
static struct resource * __insert_resource(struct resource *parent, struct resource *new)
|
|
{
|
|
struct resource *first, *next;
|
|
|
|
for (;; parent = first) {
|
|
first = __request_resource(parent, new);
|
|
if (!first)
|
|
return first;
|
|
|
|
if (first == parent)
|
|
return first;
|
|
if (WARN_ON(first == new)) /* duplicated insertion */
|
|
return first;
|
|
|
|
if ((first->start > new->start) || (first->end < new->end))
|
|
break;
|
|
if ((first->start == new->start) && (first->end == new->end))
|
|
break;
|
|
}
|
|
|
|
for (next = first; ; next = next->sibling) {
|
|
/* Partial overlap? Bad, and unfixable */
|
|
if (next->start < new->start || next->end > new->end)
|
|
return next;
|
|
if (!next->sibling)
|
|
break;
|
|
if (next->sibling->start > new->end)
|
|
break;
|
|
}
|
|
|
|
new->parent = parent;
|
|
new->sibling = next->sibling;
|
|
new->child = first;
|
|
|
|
next->sibling = NULL;
|
|
for (next = first; next; next = next->sibling)
|
|
next->parent = new;
|
|
|
|
if (parent->child == first) {
|
|
parent->child = new;
|
|
} else {
|
|
next = parent->child;
|
|
while (next->sibling != first)
|
|
next = next->sibling;
|
|
next->sibling = new;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/**
|
|
* insert_resource_conflict - Inserts resource in the resource tree
|
|
* @parent: parent of the new resource
|
|
* @new: new resource to insert
|
|
*
|
|
* Returns 0 on success, conflict resource if the resource can't be inserted.
|
|
*
|
|
* This function is equivalent to request_resource_conflict when no conflict
|
|
* happens. If a conflict happens, and the conflicting resources
|
|
* entirely fit within the range of the new resource, then the new
|
|
* resource is inserted and the conflicting resources become children of
|
|
* the new resource.
|
|
*
|
|
* This function is intended for producers of resources, such as FW modules
|
|
* and bus drivers.
|
|
*/
|
|
struct resource *insert_resource_conflict(struct resource *parent, struct resource *new)
|
|
{
|
|
struct resource *conflict;
|
|
|
|
write_lock(&resource_lock);
|
|
conflict = __insert_resource(parent, new);
|
|
write_unlock(&resource_lock);
|
|
return conflict;
|
|
}
|
|
|
|
/**
|
|
* insert_resource - Inserts a resource in the resource tree
|
|
* @parent: parent of the new resource
|
|
* @new: new resource to insert
|
|
*
|
|
* Returns 0 on success, -EBUSY if the resource can't be inserted.
|
|
*
|
|
* This function is intended for producers of resources, such as FW modules
|
|
* and bus drivers.
|
|
*/
|
|
int insert_resource(struct resource *parent, struct resource *new)
|
|
{
|
|
struct resource *conflict;
|
|
|
|
conflict = insert_resource_conflict(parent, new);
|
|
return conflict ? -EBUSY : 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(insert_resource);
|
|
|
|
/**
|
|
* insert_resource_expand_to_fit - Insert a resource into the resource tree
|
|
* @root: root resource descriptor
|
|
* @new: new resource to insert
|
|
*
|
|
* Insert a resource into the resource tree, possibly expanding it in order
|
|
* to make it encompass any conflicting resources.
|
|
*/
|
|
void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
|
|
{
|
|
if (new->parent)
|
|
return;
|
|
|
|
write_lock(&resource_lock);
|
|
for (;;) {
|
|
struct resource *conflict;
|
|
|
|
conflict = __insert_resource(root, new);
|
|
if (!conflict)
|
|
break;
|
|
if (conflict == root)
|
|
break;
|
|
|
|
/* Ok, expand resource to cover the conflict, then try again .. */
|
|
if (conflict->start < new->start)
|
|
new->start = conflict->start;
|
|
if (conflict->end > new->end)
|
|
new->end = conflict->end;
|
|
|
|
printk("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);
|
|
|
|
printk(KERN_WARNING "Trying to free nonexistent resource "
|
|
"<%016llx-%016llx>\n", (unsigned long long)start,
|
|
(unsigned long long)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;
|
|
}
|
|
|
|
/*
|
|
* All memory regions added from memory-hotplug path have the
|
|
* flag IORESOURCE_SYSTEM_RAM. If the resource does not have
|
|
* this flag, we know that we are dealing with a resource coming
|
|
* from HMM/devm. HMM/devm use another mechanism to add/release
|
|
* a resource. This goes via devm_request_mem_region and
|
|
* devm_release_mem_region.
|
|
* HMM/devm take care to release their resources when they want,
|
|
* so if we are dealing with them, let us just back off here.
|
|
*/
|
|
if (!(res->flags & IORESOURCE_SYSRAM)) {
|
|
break;
|
|
}
|
|
|
|
if (!(res->flags & IORESOURCE_MEM))
|
|
break;
|
|
|
|
if (!(res->flags & IORESOURCE_BUSY)) {
|
|
p = &res->child;
|
|
continue;
|
|
}
|
|
|
|
/* found the target resource; let's adjust accordingly */
|
|
if (res->start == start && res->end == end) {
|
|
/* free the whole entry */
|
|
*p = res->sibling;
|
|
free_resource(res);
|
|
} else if (res->start == start && res->end != end) {
|
|
/* adjust the start */
|
|
WARN_ON_ONCE(__adjust_resource(res, end + 1,
|
|
res->end - end));
|
|
} else if (res->start != start && res->end == end) {
|
|
/* adjust the end */
|
|
WARN_ON_ONCE(__adjust_resource(res, res->start,
|
|
start - res->start));
|
|
} else {
|
|
/* split into two entries - we need a new resource */
|
|
if (!new_res) {
|
|
new_res = alloc_resource(GFP_ATOMIC);
|
|
if (!new_res) {
|
|
alloc_nofail = true;
|
|
write_unlock(&resource_lock);
|
|
goto retry;
|
|
}
|
|
}
|
|
new_res->name = res->name;
|
|
new_res->start = end + 1;
|
|
new_res->end = res->end;
|
|
new_res->flags = res->flags;
|
|
new_res->desc = res->desc;
|
|
new_res->parent = res->parent;
|
|
new_res->sibling = res->sibling;
|
|
new_res->child = NULL;
|
|
|
|
if (WARN_ON_ONCE(__adjust_resource(res, res->start,
|
|
start - res->start)))
|
|
break;
|
|
res->sibling = new_res;
|
|
new_res = NULL;
|
|
}
|
|
|
|
break;
|
|
}
|
|
|
|
write_unlock(&resource_lock);
|
|
free_resource(new_res);
|
|
}
|
|
#endif /* CONFIG_MEMORY_HOTREMOVE */
|
|
|
|
#ifdef CONFIG_MEMORY_HOTPLUG
|
|
static bool system_ram_resources_mergeable(struct resource *r1,
|
|
struct resource *r2)
|
|
{
|
|
/* We assume either r1 or r2 is IORESOURCE_SYSRAM_MERGEABLE. */
|
|
return r1->flags == r2->flags && r1->end + 1 == r2->start &&
|
|
r1->name == r2->name && r1->desc == r2->desc &&
|
|
!r1->child && !r2->child;
|
|
}
|
|
|
|
/**
|
|
* merge_system_ram_resource - mark the System RAM resource mergeable and try to
|
|
* merge it with adjacent, mergeable resources
|
|
* @res: resource descriptor
|
|
*
|
|
* This interface is intended for memory hotplug, whereby lots of contiguous
|
|
* system ram resources are added (e.g., via add_memory*()) by a driver, and
|
|
* the actual resource boundaries are not of interest (e.g., it might be
|
|
* relevant for DIMMs). Only resources that are marked mergeable, that have the
|
|
* same parent, and that don't have any children are considered. All mergeable
|
|
* resources must be immutable during the request.
|
|
*
|
|
* Note:
|
|
* - The caller has to make sure that no pointers to resources that are
|
|
* marked mergeable are used anymore after this call - the resource might
|
|
* be freed and the pointer might be stale!
|
|
* - release_mem_region_adjustable() will split on demand on memory hotunplug
|
|
*/
|
|
void merge_system_ram_resource(struct resource *res)
|
|
{
|
|
const unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
|
|
struct resource *cur;
|
|
|
|
if (WARN_ON_ONCE((res->flags & flags) != flags))
|
|
return;
|
|
|
|
write_lock(&resource_lock);
|
|
res->flags |= IORESOURCE_SYSRAM_MERGEABLE;
|
|
|
|
/* Try to merge with next item in the list. */
|
|
cur = res->sibling;
|
|
if (cur && system_ram_resources_mergeable(res, cur)) {
|
|
res->end = cur->end;
|
|
res->sibling = cur->sibling;
|
|
free_resource(cur);
|
|
}
|
|
|
|
/* Try to merge with previous item in the list. */
|
|
cur = res->parent->child;
|
|
while (cur && cur->sibling != res)
|
|
cur = cur->sibling;
|
|
if (cur && system_ram_resources_mergeable(cur, res)) {
|
|
cur->end = res->end;
|
|
cur->sibling = res->sibling;
|
|
free_resource(res);
|
|
}
|
|
write_unlock(&resource_lock);
|
|
}
|
|
#endif /* CONFIG_MEMORY_HOTPLUG */
|
|
|
|
/*
|
|
* Managed region resource
|
|
*/
|
|
static void devm_resource_release(struct device *dev, void *ptr)
|
|
{
|
|
struct resource **r = ptr;
|
|
|
|
release_resource(*r);
|
|
}
|
|
|
|
/**
|
|
* devm_request_resource() - request and reserve an I/O or memory resource
|
|
* @dev: device for which to request the resource
|
|
* @root: root of the resource tree from which to request the resource
|
|
* @new: descriptor of the resource to request
|
|
*
|
|
* This is a device-managed version of request_resource(). There is usually
|
|
* no need to release resources requested by this function explicitly since
|
|
* that will be taken care of when the device is unbound from its driver.
|
|
* If for some reason the resource needs to be released explicitly, because
|
|
* of ordering issues for example, drivers must call devm_release_resource()
|
|
* rather than the regular release_resource().
|
|
*
|
|
* When a conflict is detected between any existing resources and the newly
|
|
* requested resource, an error message will be printed.
|
|
*
|
|
* Returns 0 on success or a negative error code on failure.
|
|
*/
|
|
int devm_request_resource(struct device *dev, struct resource *root,
|
|
struct resource *new)
|
|
{
|
|
struct resource *conflict, **ptr;
|
|
|
|
ptr = devres_alloc(devm_resource_release, sizeof(*ptr), GFP_KERNEL);
|
|
if (!ptr)
|
|
return -ENOMEM;
|
|
|
|
*ptr = new;
|
|
|
|
conflict = request_resource_conflict(root, new);
|
|
if (conflict) {
|
|
dev_err(dev, "resource collision: %pR conflicts with %s %pR\n",
|
|
new, conflict->name, conflict);
|
|
devres_free(ptr);
|
|
return -EBUSY;
|
|
}
|
|
|
|
devres_add(dev, ptr);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(devm_request_resource);
|
|
|
|
static int devm_resource_match(struct device *dev, void *res, void *data)
|
|
{
|
|
struct resource **ptr = res;
|
|
|
|
return *ptr == data;
|
|
}
|
|
|
|
/**
|
|
* devm_release_resource() - release a previously requested resource
|
|
* @dev: device for which to release the resource
|
|
* @new: descriptor of the resource to release
|
|
*
|
|
* Releases a resource previously requested using devm_request_resource().
|
|
*/
|
|
void devm_release_resource(struct device *dev, struct resource *new)
|
|
{
|
|
WARN_ON(devres_release(dev, devm_resource_release, devm_resource_match,
|
|
new));
|
|
}
|
|
EXPORT_SYMBOL(devm_release_resource);
|
|
|
|
struct region_devres {
|
|
struct resource *parent;
|
|
resource_size_t start;
|
|
resource_size_t n;
|
|
};
|
|
|
|
static void devm_region_release(struct device *dev, void *res)
|
|
{
|
|
struct region_devres *this = res;
|
|
|
|
__release_region(this->parent, this->start, this->n);
|
|
}
|
|
|
|
static int devm_region_match(struct device *dev, void *res, void *match_data)
|
|
{
|
|
struct region_devres *this = res, *match = match_data;
|
|
|
|
return this->parent == match->parent &&
|
|
this->start == match->start && this->n == match->n;
|
|
}
|
|
|
|
struct resource *
|
|
__devm_request_region(struct device *dev, struct resource *parent,
|
|
resource_size_t start, resource_size_t n, const char *name)
|
|
{
|
|
struct region_devres *dr = NULL;
|
|
struct resource *res;
|
|
|
|
dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
|
|
GFP_KERNEL);
|
|
if (!dr)
|
|
return NULL;
|
|
|
|
dr->parent = parent;
|
|
dr->start = start;
|
|
dr->n = n;
|
|
|
|
res = __request_region(parent, start, n, name, 0);
|
|
if (res)
|
|
devres_add(dev, dr);
|
|
else
|
|
devres_free(dr);
|
|
|
|
return res;
|
|
}
|
|
EXPORT_SYMBOL(__devm_request_region);
|
|
|
|
void __devm_release_region(struct device *dev, struct resource *parent,
|
|
resource_size_t start, resource_size_t n)
|
|
{
|
|
struct region_devres match_data = { parent, start, n };
|
|
|
|
__release_region(parent, start, n);
|
|
WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
|
|
&match_data));
|
|
}
|
|
EXPORT_SYMBOL(__devm_release_region);
|
|
|
|
/*
|
|
* Reserve I/O ports or memory based on "reserve=" kernel parameter.
|
|
*/
|
|
#define MAXRESERVE 4
|
|
static int __init reserve_setup(char *str)
|
|
{
|
|
static int reserved;
|
|
static struct resource reserve[MAXRESERVE];
|
|
|
|
for (;;) {
|
|
unsigned int io_start, io_num;
|
|
int x = reserved;
|
|
struct resource *parent;
|
|
|
|
if (get_option(&str, &io_start) != 2)
|
|
break;
|
|
if (get_option(&str, &io_num) == 0)
|
|
break;
|
|
if (x < MAXRESERVE) {
|
|
struct resource *res = reserve + x;
|
|
|
|
/*
|
|
* If the region starts below 0x10000, we assume it's
|
|
* I/O port space; otherwise assume it's memory.
|
|
*/
|
|
if (io_start < 0x10000) {
|
|
res->flags = IORESOURCE_IO;
|
|
parent = &ioport_resource;
|
|
} else {
|
|
res->flags = IORESOURCE_MEM;
|
|
parent = &iomem_resource;
|
|
}
|
|
res->name = "reserved";
|
|
res->start = io_start;
|
|
res->end = io_start + io_num - 1;
|
|
res->flags |= IORESOURCE_BUSY;
|
|
res->desc = IORES_DESC_NONE;
|
|
res->child = NULL;
|
|
if (request_resource(parent, res) == 0)
|
|
reserved = x+1;
|
|
}
|
|
}
|
|
return 1;
|
|
}
|
|
__setup("reserve=", reserve_setup);
|
|
|
|
/*
|
|
* Check if the requested addr and size spans more than any slot in the
|
|
* iomem resource tree.
|
|
*/
|
|
int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
|
|
{
|
|
struct resource *p = &iomem_resource;
|
|
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 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 iomem_is_exclusive(u64 addr)
|
|
{
|
|
const unsigned int exclusive_system_ram = IORESOURCE_SYSTEM_RAM |
|
|
IORESOURCE_EXCLUSIVE;
|
|
bool skip_children = false, err = false;
|
|
int size = PAGE_SIZE;
|
|
struct resource *p;
|
|
|
|
addr = addr & PAGE_MASK;
|
|
|
|
read_lock(&resource_lock);
|
|
for_each_resource(&iomem_resource, 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;
|
|
}
|
|
|
|
struct resource_entry *resource_list_create_entry(struct resource *res,
|
|
size_t extra_size)
|
|
{
|
|
struct resource_entry *entry;
|
|
|
|
entry = kzalloc(sizeof(*entry) + extra_size, GFP_KERNEL);
|
|
if (entry) {
|
|
INIT_LIST_HEAD(&entry->node);
|
|
entry->res = res ? res : &entry->__res;
|
|
}
|
|
|
|
return entry;
|
|
}
|
|
EXPORT_SYMBOL(resource_list_create_entry);
|
|
|
|
void resource_list_free(struct list_head *head)
|
|
{
|
|
struct resource_entry *entry, *tmp;
|
|
|
|
list_for_each_entry_safe(entry, tmp, head, node)
|
|
resource_list_destroy_entry(entry);
|
|
}
|
|
EXPORT_SYMBOL(resource_list_free);
|
|
|
|
#ifdef CONFIG_GET_FREE_REGION
|
|
#define GFR_DESCENDING (1UL << 0)
|
|
#define GFR_REQUEST_REGION (1UL << 1)
|
|
#define GFR_DEFAULT_ALIGN (1UL << PA_SECTION_SHIFT)
|
|
|
|
static resource_size_t gfr_start(struct resource *base, resource_size_t size,
|
|
resource_size_t align, unsigned long flags)
|
|
{
|
|
if (flags & GFR_DESCENDING) {
|
|
resource_size_t end;
|
|
|
|
end = min_t(resource_size_t, base->end,
|
|
(1ULL << MAX_PHYSMEM_BITS) - 1);
|
|
return end - size + 1;
|
|
}
|
|
|
|
return ALIGN(base->start, align);
|
|
}
|
|
|
|
static bool gfr_continue(struct resource *base, resource_size_t addr,
|
|
resource_size_t size, unsigned long flags)
|
|
{
|
|
if (flags & GFR_DESCENDING)
|
|
return addr > size && addr >= base->start;
|
|
/*
|
|
* In the ascend case be careful that the last increment by
|
|
* @size did not wrap 0.
|
|
*/
|
|
return addr > addr - size &&
|
|
addr <= min_t(resource_size_t, base->end,
|
|
(1ULL << MAX_PHYSMEM_BITS) - 1);
|
|
}
|
|
|
|
static resource_size_t gfr_next(resource_size_t addr, resource_size_t size,
|
|
unsigned long flags)
|
|
{
|
|
if (flags & GFR_DESCENDING)
|
|
return addr - size;
|
|
return addr + size;
|
|
}
|
|
|
|
static void remove_free_mem_region(void *_res)
|
|
{
|
|
struct resource *res = _res;
|
|
|
|
if (res->parent)
|
|
remove_resource(res);
|
|
free_resource(res);
|
|
}
|
|
|
|
static struct resource *
|
|
get_free_mem_region(struct device *dev, struct resource *base,
|
|
resource_size_t size, const unsigned long align,
|
|
const char *name, const unsigned long desc,
|
|
const unsigned long flags)
|
|
{
|
|
resource_size_t addr;
|
|
struct resource *res;
|
|
struct region_devres *dr = NULL;
|
|
|
|
size = ALIGN(size, align);
|
|
|
|
res = alloc_resource(GFP_KERNEL);
|
|
if (!res)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
if (dev && (flags & GFR_REQUEST_REGION)) {
|
|
dr = devres_alloc(devm_region_release,
|
|
sizeof(struct region_devres), GFP_KERNEL);
|
|
if (!dr) {
|
|
free_resource(res);
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
} else if (dev) {
|
|
if (devm_add_action_or_reset(dev, remove_free_mem_region, res))
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
|
|
write_lock(&resource_lock);
|
|
for (addr = gfr_start(base, size, align, flags);
|
|
gfr_continue(base, addr, size, flags);
|
|
addr = gfr_next(addr, size, flags)) {
|
|
if (__region_intersects(base, addr, size, 0, IORES_DESC_NONE) !=
|
|
REGION_DISJOINT)
|
|
continue;
|
|
|
|
if (flags & GFR_REQUEST_REGION) {
|
|
if (__request_region_locked(res, &iomem_resource, addr,
|
|
size, name, 0))
|
|
break;
|
|
|
|
if (dev) {
|
|
dr->parent = &iomem_resource;
|
|
dr->start = addr;
|
|
dr->n = size;
|
|
devres_add(dev, dr);
|
|
}
|
|
|
|
res->desc = desc;
|
|
write_unlock(&resource_lock);
|
|
|
|
|
|
/*
|
|
* A driver is claiming this region so revoke any
|
|
* mappings.
|
|
*/
|
|
revoke_iomem(res);
|
|
} else {
|
|
res->start = addr;
|
|
res->end = addr + size - 1;
|
|
res->name = name;
|
|
res->desc = desc;
|
|
res->flags = IORESOURCE_MEM;
|
|
|
|
/*
|
|
* Only succeed if the resource hosts an exclusive
|
|
* range after the insert
|
|
*/
|
|
if (__insert_resource(base, res) || res->child)
|
|
break;
|
|
|
|
write_unlock(&resource_lock);
|
|
}
|
|
|
|
return res;
|
|
}
|
|
write_unlock(&resource_lock);
|
|
|
|
if (flags & GFR_REQUEST_REGION) {
|
|
free_resource(res);
|
|
devres_free(dr);
|
|
} else if (dev)
|
|
devm_release_action(dev, remove_free_mem_region, res);
|
|
|
|
return ERR_PTR(-ERANGE);
|
|
}
|
|
|
|
/**
|
|
* devm_request_free_mem_region - find free region for device private memory
|
|
*
|
|
* @dev: device struct to bind the resource to
|
|
* @size: size in bytes of the device memory to add
|
|
* @base: resource tree to look in
|
|
*
|
|
* This function tries to find an empty range of physical address big enough to
|
|
* contain the new resource, so that it can later be hotplugged as ZONE_DEVICE
|
|
* memory, which in turn allocates struct pages.
|
|
*/
|
|
struct resource *devm_request_free_mem_region(struct device *dev,
|
|
struct resource *base, unsigned long size)
|
|
{
|
|
unsigned long flags = GFR_DESCENDING | GFR_REQUEST_REGION;
|
|
|
|
return get_free_mem_region(dev, base, size, GFR_DEFAULT_ALIGN,
|
|
dev_name(dev),
|
|
IORES_DESC_DEVICE_PRIVATE_MEMORY, flags);
|
|
}
|
|
EXPORT_SYMBOL_GPL(devm_request_free_mem_region);
|
|
|
|
struct resource *request_free_mem_region(struct resource *base,
|
|
unsigned long size, const char *name)
|
|
{
|
|
unsigned long flags = GFR_DESCENDING | GFR_REQUEST_REGION;
|
|
|
|
return get_free_mem_region(NULL, base, size, GFR_DEFAULT_ALIGN, name,
|
|
IORES_DESC_DEVICE_PRIVATE_MEMORY, flags);
|
|
}
|
|
EXPORT_SYMBOL_GPL(request_free_mem_region);
|
|
|
|
/**
|
|
* alloc_free_mem_region - find a free region relative to @base
|
|
* @base: resource that will parent the new resource
|
|
* @size: size in bytes of memory to allocate from @base
|
|
* @align: alignment requirements for the allocation
|
|
* @name: resource name
|
|
*
|
|
* Buses like CXL, that can dynamically instantiate new memory regions,
|
|
* need a method to allocate physical address space for those regions.
|
|
* Allocate and insert a new resource to cover a free, unclaimed by a
|
|
* descendant of @base, range in the span of @base.
|
|
*/
|
|
struct resource *alloc_free_mem_region(struct resource *base,
|
|
unsigned long size, unsigned long align,
|
|
const char *name)
|
|
{
|
|
/* Default of ascending direction and insert resource */
|
|
unsigned long flags = 0;
|
|
|
|
return get_free_mem_region(NULL, base, size, align, name,
|
|
IORES_DESC_NONE, flags);
|
|
}
|
|
EXPORT_SYMBOL_NS_GPL(alloc_free_mem_region, CXL);
|
|
#endif /* CONFIG_GET_FREE_REGION */
|
|
|
|
static int __init strict_iomem(char *str)
|
|
{
|
|
if (strstr(str, "relaxed"))
|
|
strict_iomem_checks = 0;
|
|
if (strstr(str, "strict"))
|
|
strict_iomem_checks = 1;
|
|
return 1;
|
|
}
|
|
|
|
static int iomem_fs_init_fs_context(struct fs_context *fc)
|
|
{
|
|
return init_pseudo(fc, DEVMEM_MAGIC) ? 0 : -ENOMEM;
|
|
}
|
|
|
|
static struct file_system_type iomem_fs_type = {
|
|
.name = "iomem",
|
|
.owner = THIS_MODULE,
|
|
.init_fs_context = iomem_fs_init_fs_context,
|
|
.kill_sb = kill_anon_super,
|
|
};
|
|
|
|
static int __init iomem_init_inode(void)
|
|
{
|
|
static struct vfsmount *iomem_vfs_mount;
|
|
static int iomem_fs_cnt;
|
|
struct inode *inode;
|
|
int rc;
|
|
|
|
rc = simple_pin_fs(&iomem_fs_type, &iomem_vfs_mount, &iomem_fs_cnt);
|
|
if (rc < 0) {
|
|
pr_err("Cannot mount iomem pseudo filesystem: %d\n", rc);
|
|
return rc;
|
|
}
|
|
|
|
inode = alloc_anon_inode(iomem_vfs_mount->mnt_sb);
|
|
if (IS_ERR(inode)) {
|
|
rc = PTR_ERR(inode);
|
|
pr_err("Cannot allocate inode for iomem: %d\n", rc);
|
|
simple_release_fs(&iomem_vfs_mount, &iomem_fs_cnt);
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
* Publish iomem revocation inode initialized.
|
|
* Pairs with smp_load_acquire() in revoke_iomem().
|
|
*/
|
|
smp_store_release(&iomem_inode, inode);
|
|
|
|
return 0;
|
|
}
|
|
|
|
fs_initcall(iomem_init_inode);
|
|
|
|
__setup("iomem=", strict_iomem);
|