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Date: Wed, 21 Jun 2017 05:53:45 +0200
From: Zoltán Böszörményi
<zboszor@...hu>
To: linux-kernel@...r.kernel.org
Cc: linux-usb@...r.kernel.org, linux-watchdog@...r.kernel.org,
linux-i2c@...r.kernel.org,
Paul Menzel <paulepanter@...rs.sourceforge.net>,
Christian Fetzer <fetzer.ch@...il.com>,
Jean Delvare <jdelvare@...e.com>,
Nehal Shah <nehal-bakulchandra.shah@....com>,
Tim Small <tim@...ss.co.uk>,
Guenter Roeck <linux@...ck-us.net>, kernel@...ss.net,
wim@...ana.be, jlayton@...chiereds.net, marc.2377@...il.com,
cshorler@...glemail.com, wsa@...-dreams.de,
regressions@...mhuis.info,
Zoltán Böszörményi
<zboszor@...hu>
Subject: [PATCH 1/5] Extend the request_region() infrastructure
Add a new IORESOURCE_ALLOCATED flag that is automatically used
when alloc_resource() is used internally in kernel/resource.c
and free_resource() now takes this flag into account.
The core of __request_region() was factored out into a new function
called __request_declared_region() that needs struct resource *
instead of the (start, n, name) triplet.
These changes allow using statically declared struct resource
data coupled with the pre-existing DEFINE_RES_IO_NAMED() static
initializer macro. The new macro exploiting
__request_declared_region() is request_declared_muxed_region()
Signed-off-by: Zoltán Böszörményi <zboszor@...hu>
---
include/linux/ioport.h | 5 +++++
kernel/resource.c | 55 +++++++++++++++++++++++++++++++++++---------------
2 files changed, 44 insertions(+), 16 deletions(-)
diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index 6230064..a3c4e08 100644
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h
@@ -52,6 +52,7 @@ struct resource {
#define IORESOURCE_MEM_64 0x00100000
#define IORESOURCE_WINDOW 0x00200000 /* forwarded by bridge */
#define IORESOURCE_MUXED 0x00400000 /* Resource is software muxed */
+#define IORESOURCE_ALLOCATED 0x00800000 /* Resource was allocated */
#define IORESOURCE_EXT_TYPE_BITS 0x01000000 /* Resource extended types */
#define IORESOURCE_SYSRAM 0x01000000 /* System RAM (modifier) */
@@ -216,12 +217,16 @@ static inline bool resource_contains(struct resource *r1, struct resource *r2)
/* Convenience shorthand with allocation */
#define request_region(start,n,name) __request_region(&ioport_resource, (start), (n), (name), 0)
#define request_muxed_region(start,n,name) __request_region(&ioport_resource, (start), (n), (name), IORESOURCE_MUXED)
+#define request_declared_muxed_region(res) __request_declared_region(&ioport_resource, (res), IORESOURCE_MUXED)
#define __request_mem_region(start,n,name, excl) __request_region(&iomem_resource, (start), (n), (name), excl)
#define request_mem_region(start,n,name) __request_region(&iomem_resource, (start), (n), (name), 0)
#define request_mem_region_exclusive(start,n,name) \
__request_region(&iomem_resource, (start), (n), (name), IORESOURCE_EXCLUSIVE)
#define rename_region(region, newname) do { (region)->name = (newname); } while (0)
+extern struct resource * __request_declared_region(struct resource *,
+ struct resource *res, int flags);
+
extern struct resource * __request_region(struct resource *,
resource_size_t start,
resource_size_t n,
diff --git a/kernel/resource.c b/kernel/resource.c
index 9b5f044..220f695 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -184,6 +184,9 @@ static void free_resource(struct resource *res)
if (!res)
return;
+ if (!(res->flags & IORESOURCE_ALLOCATED))
+ return;
+
if (!PageSlab(virt_to_head_page(res))) {
spin_lock(&bootmem_resource_lock);
res->sibling = bootmem_resource_free;
@@ -210,6 +213,8 @@ static struct resource *alloc_resource(gfp_t flags)
else
res = kzalloc(sizeof(struct resource), flags);
+ res->flags = IORESOURCE_ALLOCATED;
+
return res;
}
@@ -1117,26 +1122,15 @@ resource_size_t resource_alignment(struct resource *res)
static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait);
/**
- * __request_region - create a new busy resource region
+ * __request_declared_region - create a new busy resource region
* @parent: parent resource descriptor
- * @start: resource start address
- * @n: resource region size
- * @name: reserving caller's ID string
+ * @res: child resource descriptor
* @flags: IO resource flags
*/
-struct resource * __request_region(struct resource *parent,
- resource_size_t start, resource_size_t n,
- const char *name, int flags)
+struct resource * __request_declared_region(struct resource *parent,
+ struct resource *res, int flags)
{
DECLARE_WAITQUEUE(wait, current);
- struct resource *res = alloc_resource(GFP_KERNEL);
-
- if (!res)
- return NULL;
-
- res->name = name;
- res->start = start;
- res->end = start + n - 1;
write_lock(&resource_lock);
@@ -1166,13 +1160,42 @@ struct resource * __request_region(struct resource *parent,
continue;
}
/* Uhhuh, that didn't work out.. */
- free_resource(res);
res = NULL;
break;
}
write_unlock(&resource_lock);
return res;
}
+EXPORT_SYMBOL(__request_declared_region);
+
+/**
+ * __request_region - create a new busy resource region
+ * @parent: parent resource descriptor
+ * @start: resource start address
+ * @n: resource region size
+ * @name: reserving caller's ID string
+ * @flags: IO resource flags
+ */
+struct resource * __request_region(struct resource *parent,
+ resource_size_t start, resource_size_t n,
+ const char *name, int flags)
+{
+ struct resource *res = alloc_resource(GFP_KERNEL);
+
+ if (!res)
+ return NULL;
+
+ res->name = name;
+ res->start = start;
+ res->end = start + n - 1;
+
+ if (!__request_declared_region(parent, res, flags)) {
+ free_resource(res);
+ res = NULL;
+ }
+
+ return res;
+}
EXPORT_SYMBOL(__request_region);
/**
--
2.9.4
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