resource: add a not device managed request_free_mem_region variant

Factor out the guts of devm_request_free_mem_region so that we can
implement both a device managed and a manually release version as tiny
wrappers around it.

Link: https://lore.kernel.org/r/20190818090557.17853-2-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Bharata B Rao <bharata@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

include/linux/ioport.h

@@ -297,6 +297,8 @@ static inline bool resource_overlaps(struct resource *r1, struct resource *r2)
 
 struct resource *devm_request_free_mem_region(struct device *dev,
 		struct resource *base, unsigned long size);
+struct resource *request_free_mem_region(struct resource *base,
+		unsigned long size, const char *name);
 
 #endif /* __ASSEMBLY__ */
 #endif	/* _LINUX_IOPORT_H */

kernel/resource.c

@@ -1644,6 +1644,34 @@ void resource_list_free(struct list_head *head)
 EXPORT_SYMBOL(resource_list_free);
 
 #ifdef CONFIG_DEVICE_PRIVATE
+static struct resource *__request_free_mem_region(struct device *dev,
+		struct resource *base, unsigned long size, const char *name)
+{
+	resource_size_t end, addr;
+	struct resource *res;
+
+	size = ALIGN(size, 1UL << PA_SECTION_SHIFT);
+	end = min_t(unsigned long, base->end, (1UL << MAX_PHYSMEM_BITS) - 1);
+	addr = end - size + 1UL;
+
+	for (; addr > size && addr >= base->start; addr -= size) {
+		if (region_intersects(addr, size, 0, IORES_DESC_NONE) !=
+				REGION_DISJOINT)
+			continue;
+
+		if (dev)
+			res = devm_request_mem_region(dev, addr, size, name);
+		else
+			res = request_mem_region(addr, size, name);
+		if (!res)
+			return ERR_PTR(-ENOMEM);
+		res->desc = IORES_DESC_DEVICE_PRIVATE_MEMORY;
+		return res;
+	}
+
+	return ERR_PTR(-ERANGE);
+}
+
 /**
  * devm_request_free_mem_region - find free region for device private memory
  *
@@ -1658,28 +1686,17 @@ EXPORT_SYMBOL(resource_list_free);
 struct resource *devm_request_free_mem_region(struct device *dev,
 		struct resource *base, unsigned long size)
 {
-	resource_size_t end, addr;
-	struct resource *res;
-
-	size = ALIGN(size, 1UL << PA_SECTION_SHIFT);
-	end = min_t(unsigned long, base->end, (1UL << MAX_PHYSMEM_BITS) - 1);
-	addr = end - size + 1UL;
-
-	for (; addr > size && addr >= base->start; addr -= size) {
-		if (region_intersects(addr, size, 0, IORES_DESC_NONE) !=
-				REGION_DISJOINT)
-			continue;
-
-		res = devm_request_mem_region(dev, addr, size, dev_name(dev));
-		if (!res)
-			return ERR_PTR(-ENOMEM);
-		res->desc = IORES_DESC_DEVICE_PRIVATE_MEMORY;
-		return res;
-	}
-
-	return ERR_PTR(-ERANGE);
+	return __request_free_mem_region(dev, base, size, dev_name(dev));
 }
 EXPORT_SYMBOL_GPL(devm_request_free_mem_region);
+
+struct resource *request_free_mem_region(struct resource *base,
+		unsigned long size, const char *name)
+{
+	return __request_free_mem_region(NULL, base, size, name);
+}
+EXPORT_SYMBOL_GPL(request_free_mem_region);
+
 #endif /* CONFIG_DEVICE_PRIVATE */
 
 static int __init strict_iomem(char *str)