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![Daniel Vetter](/assets/img/avatar_default.png)
We want all iomem mmaps to consistently revoke ptes when the kernel takes over and CONFIG_IO_STRICT_DEVMEM is enabled. This includes the pci bar mmaps available through procfs and sysfs, which currently do not revoke mappings. To prepare for this, move the code from the /dev/kmem driver to kernel/resource.c. During review Jason spotted that barriers are used somewhat inconsistently. Fix that up while we shuffle this code, since it doesn't have an actual impact at runtime. Otherwise no semantic and behavioural changes intended, just code extraction and adjusting comments and names. Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Kees Cook <keescook@chromium.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Dan Williams <dan.j.williams@intel.com> Cc: linux-mm@kvack.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-samsung-soc@vger.kernel.org Cc: linux-media@vger.kernel.org Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: David Hildenbrand <david@redhat.com> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/20201127164131.2244124-11-daniel.vetter@ffwll.ch
1885 lines
48 KiB
C
1885 lines
48 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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/*
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* For memory hotplug, there is no way to free resource entries allocated
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* by boot mem after the system is up. So for reusing the resource entry
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* we need to remember the resource.
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*/
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static struct resource *bootmem_resource_free;
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static DEFINE_SPINLOCK(bootmem_resource_lock);
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static struct resource *next_resource(struct resource *p, bool sibling_only)
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{
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/* Caller wants to traverse through siblings only */
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if (sibling_only)
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return p->sibling;
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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 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, false);
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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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if (!res)
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return;
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if (!PageSlab(virt_to_head_page(res))) {
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spin_lock(&bootmem_resource_lock);
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res->sibling = bootmem_resource_free;
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bootmem_resource_free = res;
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spin_unlock(&bootmem_resource_lock);
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} else {
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kfree(res);
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}
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}
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static struct resource *alloc_resource(gfp_t flags)
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{
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struct resource *res = NULL;
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spin_lock(&bootmem_resource_lock);
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if (bootmem_resource_free) {
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res = bootmem_resource_free;
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bootmem_resource_free = res->sibling;
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}
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spin_unlock(&bootmem_resource_lock);
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if (res)
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memset(res, 0, sizeof(struct resource));
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else
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res = kzalloc(sizeof(struct resource), flags);
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return res;
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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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* This function walks the whole tree and not just first level children
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* unless @first_lvl is true.
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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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* @first_lvl: walk only the first level children, if set
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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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bool first_lvl, struct resource *res)
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{
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bool siblings_only = true;
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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, siblings_only)) {
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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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/*
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* Now that we found a range that matches what we look for,
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* check the flags and the descriptor. If we were not asked to
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* use only the first level, start looking at children as well.
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*/
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siblings_only = first_lvl;
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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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bool first_lvl, 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, first_lvl, &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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* This walks through whole tree and not just first level children.
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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, false, 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, true,
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arg, 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, true,
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arg, 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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* This will find System RAM ranges that are children of top-level resources
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* in addition to top-level System RAM resources.
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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,
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false, &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;
|
|
}
|
|
|
|
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);
|
|
|
|
/**
|
|
* 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)
|
|
{
|
|
struct resource res;
|
|
int type = 0; int other = 0;
|
|
struct resource *p;
|
|
|
|
res.start = start;
|
|
res.end = start + size - 1;
|
|
|
|
read_lock(&resource_lock);
|
|
for (p = iomem_resource.child; p ; p = p->sibling) {
|
|
bool is_type = (((p->flags & flags) == flags) &&
|
|
((desc == IORES_DESC_NONE) ||
|
|
(desc == p->desc)));
|
|
|
|
if (resource_overlaps(p, &res))
|
|
is_type ? type++ : other++;
|
|
}
|
|
read_unlock(&resource_lock);
|
|
|
|
if (type == 0)
|
|
return REGION_DISJOINT;
|
|
|
|
if (other == 0)
|
|
return REGION_INTERSECTS;
|
|
|
|
return REGION_MIXED;
|
|
}
|
|
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);
|
|
}
|
|
|
|
/**
|
|
* 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;
|
|
}
|
|
|
|
/**
|
|
* __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)
|
|
{
|
|
DECLARE_WAITQUEUE(wait, current);
|
|
struct resource *res = alloc_resource(GFP_KERNEL);
|
|
struct resource *orig_parent = parent;
|
|
|
|
if (!res)
|
|
return NULL;
|
|
|
|
res->name = name;
|
|
res->start = start;
|
|
res->end = start + n - 1;
|
|
|
|
write_lock(&resource_lock);
|
|
|
|
for (;;) {
|
|
struct resource *conflict;
|
|
|
|
res->flags = resource_type(parent) | resource_ext_type(parent);
|
|
res->flags |= IORESOURCE_BUSY | flags;
|
|
res->desc = parent->desc;
|
|
|
|
conflict = __request_resource(parent, res);
|
|
if (!conflict)
|
|
break;
|
|
/*
|
|
* mm/hmm.c reserves physical addresses which then
|
|
* become unavailable to other users. Conflicts are
|
|
* not expected. Warn to aid debugging if encountered.
|
|
*/
|
|
if (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.. */
|
|
free_resource(res);
|
|
res = NULL;
|
|
break;
|
|
}
|
|
write_unlock(&resource_lock);
|
|
|
|
if (res && orig_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 reserved in the iomem resource tree
|
|
* returns true if reserved, false if not reserved.
|
|
*/
|
|
bool iomem_is_exclusive(u64 addr)
|
|
{
|
|
struct resource *p = &iomem_resource;
|
|
bool err = false;
|
|
loff_t l;
|
|
int size = PAGE_SIZE;
|
|
|
|
if (!strict_iomem_checks)
|
|
return false;
|
|
|
|
addr = addr & PAGE_MASK;
|
|
|
|
read_lock(&resource_lock);
|
|
for (p = p->child; p ; p = r_next(NULL, p, &l)) {
|
|
/*
|
|
* We can probably skip the resources without
|
|
* IORESOURCE_IO attribute?
|
|
*/
|
|
if (p->start >= addr + size)
|
|
break;
|
|
if (p->end < addr)
|
|
continue;
|
|
/*
|
|
* A resource is exclusive if IORESOURCE_EXCLUSIVE is set
|
|
* or CONFIG_IO_STRICT_DEVMEM is enabled and the
|
|
* resource is busy.
|
|
*/
|
|
if ((p->flags & IORESOURCE_BUSY) == 0)
|
|
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_DEVICE_PRIVATE
|
|
static struct resource *__request_free_mem_region(struct device *dev,
|
|
struct resource *base, unsigned long size, const char *name)
|
|
{
|
|
resource_size_t end, addr;
|
|
struct resource *res;
|
|
|
|
size = ALIGN(size, 1UL << PA_SECTION_SHIFT);
|
|
end = min_t(unsigned long, base->end, (1UL << MAX_PHYSMEM_BITS) - 1);
|
|
addr = end - size + 1UL;
|
|
|
|
for (; addr > size && addr >= base->start; addr -= size) {
|
|
if (region_intersects(addr, size, 0, IORES_DESC_NONE) !=
|
|
REGION_DISJOINT)
|
|
continue;
|
|
|
|
if (dev)
|
|
res = devm_request_mem_region(dev, addr, size, name);
|
|
else
|
|
res = request_mem_region(addr, size, name);
|
|
if (!res)
|
|
return ERR_PTR(-ENOMEM);
|
|
res->desc = IORES_DESC_DEVICE_PRIVATE_MEMORY;
|
|
return 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)
|
|
{
|
|
return __request_free_mem_region(dev, base, size, dev_name(dev));
|
|
}
|
|
EXPORT_SYMBOL_GPL(devm_request_free_mem_region);
|
|
|
|
struct resource *request_free_mem_region(struct resource *base,
|
|
unsigned long size, const char *name)
|
|
{
|
|
return __request_free_mem_region(NULL, base, size, name);
|
|
}
|
|
EXPORT_SYMBOL_GPL(request_free_mem_region);
|
|
|
|
#endif /* CONFIG_DEVICE_PRIVATE */
|
|
|
|
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);
|