From: Toshi Kani <[email protected]> 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. Signed-off-by: Toshi Kani <[email protected]> Requested-by: Borislav Petkov <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Dan Williams <[email protected]> Cc: Hanjun Guo <[email protected]> Cc: Jakub Sitnicki <[email protected]> Cc: Jiang Liu <[email protected]> Cc: [email protected] Cc: linux-mm <[email protected]> Cc: "Rafael J. Wysocki" <[email protected]> Link: http://lkml.kernel.org/r/[email protected] [ Boris: fixup comments. ] Signed-off-by: Borislav Petkov <[email protected]> --- include/linux/ioport.h | 3 +++ kernel/resource.c | 66 ++++++++++++++++++++++++++++++++++++++++++-------- 2 files changed, 59 insertions(+), 10 deletions(-) diff --git a/include/linux/ioport.h b/include/linux/ioport.h index 983bea05d69c..2a4a5e839965 100644 --- a/include/linux/ioport.h +++ b/include/linux/ioport.h @@ -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 *)); diff --git a/kernel/resource.c b/kernel/resource.c index 0041cedc47d6..37ed2fcb8246 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -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) -- 2.3.5
