-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".

- */