From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754698Ab3KTRwP (ORCPT ); Wed, 20 Nov 2013 12:52:15 -0500 Received: from mx1.redhat.com ([209.132.183.28]:34803 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753874Ab3KTRwJ (ORCPT ); Wed, 20 Nov 2013 12:52:09 -0500 From: Vivek Goyal To: linux-kernel@vger.kernel.org, kexec@lists.infradead.org Cc: ebiederm@xmission.com, hpa@zytor.com, mjg59@srcf.ucam.org, greg@kroah.com, Vivek Goyal , Yinghai Lu Subject: [PATCH 3/6] resource: Provide new functions to walk through resources Date: Wed, 20 Nov 2013 12:50:48 -0500 Message-Id: <1384969851-7251-4-git-send-email-vgoyal@redhat.com> In-Reply-To: <1384969851-7251-1-git-send-email-vgoyal@redhat.com> References: <1384969851-7251-1-git-send-email-vgoyal@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I have added two more functions to walk through resources. Current walk_system_ram_range() deals with pfn and /proc/iomem can contain partial pages. By dealing in pfn, callback function loses the info that last page of a memory range is a partial page and not the full page. So I implemented walk_system_ran_res() which returns u64 values to callback functions and now it properly return start and end address. walk_system_ram_range() uses find_next_system_ram() to find the next ram resource. This in turn only travels through siblings of top level child and does not travers through all the nodes of the resoruce tree. I also need another function where I can walk through all the resources, for example figure out where "GART" aperture is. Figure out where ACPI memory is. So I wrote another function walk_ram_res() which walks through all /proc/iomem resources and returns matches as asked by caller. Caller can specify "name" of resource, start and end. Signed-off-by: Vivek Goyal Cc: Yinghai Lu --- include/linux/ioport.h | 6 +++ kernel/resource.c | 108 ++++++++++++++++++++++++++++++++++++++++++++++-- 2 files changed, 110 insertions(+), 4 deletions(-) diff --git a/include/linux/ioport.h b/include/linux/ioport.h index 89b7c24..0ebf8b0 100644 --- a/include/linux/ioport.h +++ b/include/linux/ioport.h @@ -227,6 +227,12 @@ extern int iomem_is_exclusive(u64 addr); extern int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages, void *arg, int (*func)(unsigned long, unsigned long, void *)); +extern int +walk_system_ram_res(u64 start, u64 end, void *arg, + int (*func)(u64, u64, void *)); +extern int +walk_ram_res(char *name, unsigned long flags, u64 start, u64 end, void *arg, + int (*func)(u64, u64, void *)); /* True if any part of r1 overlaps r2 */ static inline bool resource_overlaps(struct resource *r1, struct resource *r2) diff --git a/kernel/resource.c b/kernel/resource.c index 3f285dc..5e575e8 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -59,10 +59,8 @@ static DEFINE_RWLOCK(resource_lock); static struct resource *bootmem_resource_free; static DEFINE_SPINLOCK(bootmem_resource_lock); -static void *r_next(struct seq_file *m, void *v, loff_t *pos) +static struct resource *next_resource(struct resource *p) { - struct resource *p = v; - (*pos)++; if (p->child) return p->child; while (!p->sibling && p->parent) @@ -70,6 +68,13 @@ static void *r_next(struct seq_file *m, void *v, loff_t *pos) return p->sibling; } +static void *r_next(struct seq_file *m, void *v, loff_t *pos) +{ + struct resource *p = v; + (*pos)++; + return (void *)next_resource(p); +} + #ifdef CONFIG_PROC_FS enum { MAX_IORES_LEVEL = 5 }; @@ -322,7 +327,71 @@ int release_resource(struct resource *old) EXPORT_SYMBOL(release_resource); -#if !defined(CONFIG_ARCH_HAS_WALK_MEMORY) +/* + * 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. + */ +static int find_next_iomem_res(struct resource *res, char *name) +{ + resource_size_t start, end; + struct resource *p; + + BUG_ON(!res); + + start = res->start; + end = res->end; + BUG_ON(start >= end); + + read_lock(&resource_lock); + p = &iomem_resource; + while ((p = next_resource(p))) { + if (p->flags != res->flags) + continue; + if (name && strcmp(p->name, name)) + continue; + if (p->start > end) { + p = NULL; + break; + } + if ((p->end >= start) && (p->start < end)) + break; + } + + read_unlock(&resource_lock); + if (!p) + return -1; + /* copy data */ + if (res->start < p->start) + res->start = p->start; + if (res->end > p->end) + res->end = p->end; + return 0; +} + +int walk_ram_res(char *name, 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 = IORESOURCE_MEM | IORESOURCE_BUSY; + orig_end = res.end; + while ((res.start < res.end) && + (find_next_iomem_res(&res, name) >= 0)) { + ret = (*func)(res.start, res.end, arg); + if (ret) + break; + res.start = res.end + 1; + res.end = orig_end; + } + return ret; +} + /* * Finds the lowest memory reosurce exists within [res->start.res->end) * the caller must specify res->start, res->end, res->flags and "name". @@ -367,6 +436,37 @@ static int find_next_system_ram(struct resource *res, char *name) /* * This function calls callback against all memory range of "System RAM" * which are marked as IORESOURCE_MEM and IORESOUCE_BUSY. + * Now, this function is only for "System RAM". This function deals with + * full ranges and not pfn. If resources are not pfn aligned, dealing + * with pfn can truncate ranges. + */ +int walk_system_ram_res(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 = IORESOURCE_MEM | IORESOURCE_BUSY; + orig_end = res.end; + while ((res.start < res.end) && + (find_next_system_ram(&res, "System RAM") >= 0)) { + ret = (*func)(res.start, res.end, arg); + if (ret) + break; + res.start = res.end + 1; + res.end = orig_end; + } + return ret; +} + +#if !defined(CONFIG_ARCH_HAS_WALK_MEMORY) + +/* + * This function calls callback against all memory range of "System RAM" + * which are marked as IORESOURCE_MEM and IORESOUCE_BUSY. * Now, this function is only for "System RAM". */ int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages, -- 1.7.7.6