[RFC Part1 PATCH v3 09/17] resource: Consolidate resource walking code

Brijesh Singh
2017-07-24T19:07:49Z

From: Tom Lendacky <thomas.lendacky-5C7GfCeVMHo@public.gmane.org>

The walk_iomem_res_desc(), walk_system_ram_res() and walk_system_ram_range()
functions each have much of the same code. Create a new function that
consolidates the common code from these functions in one place to reduce
the amount of duplicated code.

Signed-off-by: Tom Lendacky <thomas.lendacky-5C7GfCeVMHo@public.gmane.org>
Signed-off-by: Brijesh Singh <brijesh.singh-5C7GfCeVMHo@public.gmane.org>
---
kernel/resource.c | 53 ++++++++++++++++++++++++++---------------------------
1 file changed, 26 insertions(+), 27 deletions(-)

diff --git a/kernel/resource.c b/kernel/resource.c
index 9b5f044..7b20b3e 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -397,9 +397,30 @@ static int find_next_iomem_res(struct resource *res, unsigned long desc,
res->start = p->start;
if (res->end > p->end)
res->end = p->end;
+ res->desc = p->desc;
return 0;
}

+static int __walk_iomem_res_desc(struct resource *res, unsigned long desc,
+ bool first_level_children_only,
+ void *arg, int (*func)(u64, u64, void *))
+{
+ u64 orig_end = res->end;
+ int ret = -1;
+
+ while ((res->start < res->end) &&
+ !find_next_iomem_res(res, desc, first_level_children_only)) {
+ 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 through whole tree and not just first level children.
@@ -418,26 +439,12 @@ 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, false))) {
-
- ret = (*func)(res.start, res.end, arg);
- if (ret)
- break;
-
- res.start = res.end + 1;
- res.end = orig_end;
- }

- return ret;
+ return __walk_iomem_res_desc(&res, desc, false, arg, func);
}

/*
@@ -451,22 +458,13 @@ 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_SYSTEM_RAM | IORESOURCE_BUSY;
- orig_end = res.end;
- while ((res.start < res.end) &&
- (!find_next_iomem_res(&res, IORES_DESC_NONE, true))) {
- ret = (*func)(res.start, res.end, arg);
- if (ret)
- break;
- res.start = res.end + 1;
- res.end = orig_end;
- }
- return ret;
+
+ return __walk_iomem_res_desc(&res, IORES_DESC_NONE, true,
+ arg, func);
}

#if !defined(CONFIG_ARCH_HAS_WALK_MEMORY)
@@ -508,6 +506,7 @@ static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg)
{
return 1;
}
+
/*
* This generic page_is_ram() returns true if specified address is
* registered as System RAM in iomem_resource list.
--
2.9.4