diff options
Diffstat (limited to 'k3')
| -rw-r--r-- | k3 | 188 |
1 files changed, 188 insertions, 0 deletions
@@ -0,0 +1,188 @@ +From vgoyal@redhat.com Wed Nov 20 09:51:43 2013 +From: Vivek Goyal <vgoyal@redhat.com> +Date: Wed, 20 Nov 2013 12:50:48 -0500 +Subject: [PATCH 3/6] resource: Provide new functions to walk through resources +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 <vgoyal@redhat.com>, Yinghai Lu <yinghai@kernel.org> +Message-ID: <1384969851-7251-4-git-send-email-vgoyal@redhat.com> + + +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 <vgoyal@redhat.com> +Cc: Yinghai Lu <yinghai@kernel.org> +--- + include/linux/ioport.h | 6 ++ + kernel/resource.c | 108 +++++++++++++++++++++++++++++++++++++++++++++++-- + 2 files changed, 110 insertions(+), 4 deletions(-) + +--- 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) +--- 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, + 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 *ol + + 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". +@@ -366,6 +435,37 @@ static int find_next_system_ram(struct r + + /* + * 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". + */ |