From 97523a4edb7b9dc2be48a24a2387fb1328b29521 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Thu, 6 May 2021 18:05:20 -0700 Subject: [PATCH] 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 Reviewed-by: Dan Williams Reviewed-by: Andy Shevchenko Cc: Greg Kroah-Hartman Cc: Dan Williams Cc: Daniel Vetter Cc: Andy Shevchenko Cc: Mauro Carvalho Chehab Cc: Dave Young Cc: Baoquan He Cc: Vivek Goyal Cc: Dave Hansen Cc: Keith Busch Cc: Michal Hocko Cc: Qian Cai Cc: Oscar Salvador Cc: Eric Biederman Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: "H. Peter Anvin" Cc: Tom Lendacky Cc: Brijesh Singh Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/resource.c | 45 ++++++++++++--------------------------------- 1 file changed, 12 insertions(+), 33 deletions(-) diff --git a/kernel/resource.c b/kernel/resource.c index 16e0c7e..7e00239 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -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) -- 2.7.4