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kernel/resource: remove first_lvl / siblings_only logic 

All functions that search for IORESOURCE_SYSTEM_RAM or IORESOURCE_MEM
resources now properly consider the whole resource tree, not just the
first level.  Let's drop the unused first_lvl / siblings_only logic.

Remove documentation that indicates that some functions behave differently,
all consider the full resource tree now.

Link: https://lkml.kernel.org/r/20210325115326.7826-4-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Cc: Dave Young <dyoung@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
David Hildenbrand 2021-05-06 18:05:20 -07:00 committed by Linus Torvalds
parent 3c9c797534
commit 97523a4edb
1 changed files with 12 additions and 33 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

45
kernel/resource.c
View File

@ -64,12 +64,8 @@ static DEFINE_RWLOCK(resource_lock);
static struct resource *bootmem_resource_free;
static DEFINE_SPINLOCK(bootmem_resource_lock);
static struct resource *next_resource(struct resource *p, bool sibling_only)
static struct resource *next_resource(struct resource *p)
{
/* Caller wants to traverse through siblings only */
if (sibling_only)
return p->sibling;
if (p->child)
return p->child;
while (!p->sibling && p->parent)
@ -81,7 +77,7 @@ static void *r_next(struct seq_file *m, void *v, loff_t *pos)
{
struct resource *p = v;
(*pos)++;
return (void *)next_resource(p, false);
return (void *)next_resource(p);
}
#ifdef CONFIG_PROC_FS
@ -330,14 +326,10 @@ EXPORT_SYMBOL(release_resource);
* of the resource that's within [@start..@end]; if none is found, returns
* -ENODEV. Returns -EINVAL for invalid parameters.
*
* This function walks the whole tree and not just first level children
* unless @first_lvl is true.
*
* @start: start address of the resource searched for
* @end: end address of same resource
* @flags: flags which the resource must have
* @desc: descriptor the resource must have
* @first_lvl: walk only the first level children, if set
* @res: return ptr, if resource found
*
* The caller must specify @start, @end, @flags, and @desc
@ -345,9 +337,8 @@ EXPORT_SYMBOL(release_resource);
*/
static int find_next_iomem_res(resource_size_t start, resource_size_t end,
unsigned long flags, unsigned long desc,
bool first_lvl, struct resource *res)
struct resource *res)
{
bool siblings_only = true;
struct resource *p;
if (!res)
@ -358,7 +349,7 @@ static int find_next_iomem_res(resource_size_t start, resource_size_t end,
read_lock(&resource_lock);
for (p = iomem_resource.child; p; p = next_resource(p, siblings_only)) {
for (p = iomem_resource.child; p; p = next_resource(p)) {
/* If we passed the resource we are looking for, stop */
if (p->start > end) {
p = NULL;
@ -369,13 +360,6 @@ static int find_next_iomem_res(resource_size_t start, resource_size_t end,
if (p->end < start)
continue;
/*
* Now that we found a range that matches what we look for,
* check the flags and the descriptor. If we were not asked to
* use only the first level, start looking at children as well.
*/
siblings_only = first_lvl;
if ((p->flags & flags) != flags)
continue;
if ((desc != IORES_DESC_NONE) && (desc != p->desc))
@ -402,14 +386,14 @@ static int find_next_iomem_res(resource_size_t start, resource_size_t end,
static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end,
unsigned long flags, unsigned long desc,
bool first_lvl, void *arg,
void *arg,
int (*func)(struct resource *, void *))
{
struct resource res;
int ret = -EINVAL;
while (start < end &&
!find_next_iomem_res(start, end, flags, desc, first_lvl, &res)) {
!find_next_iomem_res(start, end, flags, desc, &res)) {
ret = (*func)(&res, arg);
if (ret)
break;
@ -431,7 +415,6 @@ static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end,
* @arg: function argument for the callback @func
* @func: callback function that is called for each qualifying resource area
*
* This walks through whole tree and not just first level children.
* All the memory ranges which overlap start,end and also match flags and
* desc are valid candidates.
*
@ -441,7 +424,7 @@ static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end,
int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start,
u64 end, void *arg, int (*func)(struct resource *, void *))
{
return __walk_iomem_res_desc(start, end, flags, desc, false, arg, func);
return __walk_iomem_res_desc(start, end, flags, desc, arg, func);
}
EXPORT_SYMBOL_GPL(walk_iomem_res_desc);
@ -457,8 +440,8 @@ int walk_system_ram_res(u64 start, u64 end, void *arg,
{
unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, false,
arg, func);
return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, arg,
func);
}
/*
@ -470,17 +453,14 @@ int walk_mem_res(u64 start, u64 end, void *arg,
{
unsigned long flags = IORESOURCE_MEM | IORESOURCE_BUSY;
return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, false,
arg, func);
return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, arg,
func);
}
/*
* This function calls the @func callback against all memory ranges of type
* System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
* It is to be used only for System RAM.
*
* This will find System RAM ranges that are children of top-level resources
* in addition to top-level System RAM resources.
*/
int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
void *arg, int (*func)(unsigned long, unsigned long, void *))
@ -495,8 +475,7 @@ int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
while (start < end &&
!find_next_iomem_res(start, end, flags, IORES_DESC_NONE,
false, &res)) {
!find_next_iomem_res(start, end, flags, IORES_DESC_NONE, &res)) {
pfn = PFN_UP(res.start);
end_pfn = PFN_DOWN(res.end + 1);
if (end_pfn > pfn)