Commit 3f33647c authored by Toshi Kani's avatar Toshi Kani Committed by Ingo Molnar
Browse files

resource: Add walk_iomem_res_desc() 



Add a new interface, walk_iomem_res_desc(), which walks through
the iomem table by identifying a target with @flags and @desc.
This interface provides the same functionality as
walk_iomem_res(), but does not use strcmp() to @name for better
efficiency.

walk_iomem_res() is deprecated and will be removed in a later
patch.

Requested-by: default avatarBorislav Petkov <bp@suse.de>
Signed-off-by: default avatarToshi Kani <toshi.kani@hpe.com>
[ Fixup comments. ]
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Hanjun Guo <hanjun.guo@linaro.org>
Cc: Jakub Sitnicki <jsitnicki@gmail.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-mm <linux-mm@kvack.org>
Link: http://lkml.kernel.org/r/1453841853-11383-14-git-send-email-bp@alien8.de


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 1c29f25b

include/linux/ioport.h

+3 −0
Original line number Diff line number Diff line
@@ -268,6 +268,9 @@ extern int 
walk_system_ram_res(u64 start, u64 end, void *arg,

		    int (*func)(u64, u64, void *));

extern int

walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start, u64 end,

		    void *arg, int (*func)(u64, u64, void *));

extern int

walk_iomem_res(char *name, unsigned long flags, u64 start, u64 end, void *arg,

	       int (*func)(u64, u64, void *));

kernel/resource.c

+56 −10
Original line number Diff line number Diff line
@@ -333,14 +333,15 @@ int release_resource(struct resource *old) 
EXPORT_SYMBOL(release_resource);



/*

 * Finds the lowest iomem reosurce exists with-in [res->start.res->end)

 * the caller must specify res->start, res->end, res->flags and "name".

 * If found, returns 0, res is overwritten, if not found, returns -1.

 * This walks through whole tree and not just first level children

 * until and unless first_level_children_only is true.

 * Finds the lowest iomem resource existing within [res->start.res->end).

 * The caller must specify res->start, res->end, res->flags, and optionally

 * desc and "name".  If found, returns 0, res is overwritten, if not found,

 * returns -1.

 * This function walks the whole tree and not just first level children until

 * and unless first_level_children_only is true.

 */

static int find_next_iomem_res(struct resource *res, char *name,

			       bool first_level_children_only)

static int find_next_iomem_res(struct resource *res, unsigned long desc,

			       char *name, bool first_level_children_only)

{

	resource_size_t start, end;

	struct resource *p;
@@ -360,6 +361,8 @@ static int find_next_iomem_res(struct resource *res, char *name, 
	for (p = iomem_resource.child; p; p = next_resource(p, sibling_only)) {

		if ((p->flags & res->flags) != res->flags)

			continue;

		if ((desc != IORES_DESC_NONE) && (desc != p->desc))

			continue;

		if (name && strcmp(p->name, name))

			continue;

		if (p->start > end) {
@@ -385,12 +388,55 @@ static int find_next_iomem_res(struct resource *res, char *name, 
 * Walks through iomem resources and calls func() with matching resource

 * ranges. 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.

 *

 * @desc: I/O resource descriptor. Use IORES_DESC_NONE to skip @desc check.

 * @flags: I/O resource flags

 * @start: start addr

 * @end: end addr

 *

 * NOTE: For a new descriptor search, define a new IORES_DESC in

 * <linux/ioport.h> and set it in 'desc' of a target resource entry.

 */

int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start,

		u64 end, void *arg, int (*func)(u64, u64, void *))

{

	struct resource res;

	u64 orig_end;

	int ret = -1;



	res.start = start;

	res.end = end;

	res.flags = flags;

	orig_end = res.end;



	while ((res.start < res.end) &&

		(!find_next_iomem_res(&res, desc, NULL, false))) {



		ret = (*func)(res.start, res.end, arg);

		if (ret)

			break;



		res.start = res.end + 1;

		res.end = orig_end;

	}



	return ret;

}



/*

 * Walks through iomem resources and calls @func with matching resource

 * ranges. This walks the whole tree and not just first level children.

 * All the memory ranges which overlap start,end and also match flags and

 * name are valid candidates.

 *

 * @name: name of resource

 * @flags: resource flags

 * @start: start addr

 * @end: end addr

 *

 * NOTE: This function is deprecated and should not be used in new code.

 * Use walk_iomem_res_desc(), instead.

 */

int walk_iomem_res(char *name, unsigned long flags, u64 start, u64 end,

		void *arg, int (*func)(u64, u64, void *))
@@ -404,7 +450,7 @@ int walk_iomem_res(char *name, unsigned long flags, u64 start, u64 end, 
	res.flags = flags;

	orig_end = res.end;

	while ((res.start < res.end) &&

		(!find_next_iomem_res(&res, name, false))) {

		(!find_next_iomem_res(&res, IORES_DESC_NONE, name, false))) {

		ret = (*func)(res.start, res.end, arg);

		if (ret)

			break;
@@ -433,7 +479,7 @@ int walk_system_ram_res(u64 start, u64 end, void *arg, 
	res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;

	orig_end = res.end;

	while ((res.start < res.end) &&

		(!find_next_iomem_res(&res, NULL, true))) {

		(!find_next_iomem_res(&res, IORES_DESC_NONE, NULL, true))) {

		ret = (*func)(res.start, res.end, arg);

		if (ret)

			break;
@@ -463,7 +509,7 @@ int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages, 
	res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;

	orig_end = res.end;

	while ((res.start < res.end) &&

		(find_next_iomem_res(&res, NULL, true) >= 0)) {

		(find_next_iomem_res(&res, IORES_DESC_NONE, NULL, true) >= 0)) {

		pfn = (res.start + PAGE_SIZE - 1) >> PAGE_SHIFT;

		end_pfn = (res.end + 1) >> PAGE_SHIFT;

		if (end_pfn > pfn)

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