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From: =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= <ilpo.jarvinen@linux.intel.com>
To: linux-pci@vger.kernel.org,
	Bjorn Helgaas <bhelgaas@google.com>,
	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Rob Herring <robh@kernel.org>,
	=?UTF-8?q?Krzysztof=20Wilczy=C5=84ski?= <kw@linux.com>,
	Igor Mammedov <imammedo@redhat.com>,
	Lukas Wunner <lukas@wunner.de>,
	Mika Westerberg <mika.westerberg@linux.intel.com>,
	Andy Shevchenko <andriy.shevchenko@intel.com>,
	"Rafael J . Wysocki" <rafael@kernel.org>,
	linux-kernel@vger.kernel.org
Cc: =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= <ilpo.jarvinen@linux.intel.com>
Subject: [PATCH 6/7] resource: Export find_empty_resource_slot()
Date: Fri, 22 Dec 2023 14:29:00 +0200
Message-Id: <20231222122901.49538-7-ilpo.jarvinen@linux.intel.com>
In-Reply-To: <20231222122901.49538-1-ilpo.jarvinen@linux.intel.com>
References: <20231222122901.49538-1-ilpo.jarvinen@linux.intel.com>
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PCI bridge window logic needs to find out in advance to the actual
allocation if there is an empty slot big enough to fit the window.

Export find_empty_resource_slot() for the purpose. Also move the struct
resource_constraint into generic header to be able to use the new
interface.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---
 include/linux/ioport.h | 22 ++++++++++++++++++++++
 kernel/resource.c      | 25 ++++---------------------
 2 files changed, 26 insertions(+), 21 deletions(-)

diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index ce02f45e9c2c..0e911393dfb2 100644
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h
@@ -205,6 +205,24 @@ typedef resource_size_t (*resource_alignf)(void *data,
 					   resource_size_t size,
 					   resource_size_t align);
 
+/**
+ * resource_constraint - constraints to be met while searching empty resource slots
+ * @min:		The minimum address for the memory range
+ * @max:		The maximum address for the memory range
+ * @align:		Alignment for the start address of the empty slot
+ * @alignf:		Additional alignment constraints callback
+ * @alignf_data:	Data provided for @alignf callback
+ *
+ * Contains the range and alignment constraints that have to be met during
+ * find_empty_resource_slot(). @alignf can be NULL indicating no alignment
+ * beyond @align is necessary.
+ */
+struct resource_constraint {
+	resource_size_t min, max, align;
+	resource_alignf alignf;
+	void *alignf_data;
+};
+
 /* PC/ISA/whatever - the normal PC address spaces: IO and memory */
 extern struct resource ioport_resource;
 extern struct resource iomem_resource;
@@ -278,6 +296,10 @@ static inline bool resource_union(const struct resource *r1, const struct resour
 	return true;
 }
 
+int find_empty_resource_slot(struct resource *root, struct resource *new,
+			     resource_size_t size,
+			     struct resource_constraint *constraint);
+
 /* 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)
diff --git a/kernel/resource.c b/kernel/resource.c
index 80d64b6467b3..2dfe04ba24f3 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -46,24 +46,6 @@ struct resource iomem_resource = {
 };
 EXPORT_SYMBOL(iomem_resource);
 
-/**
- * resource_constraint - constraints to be met while searching empty resource slots
- * @min:		The minimum address for the memory range
- * @max:		The maximum address for the memory range
- * @align:		Alignment for the start address of the empty slot
- * @alignf:		Additional alignment constraints callback
- * @alignf_data:	Data provided for @alignf callback
- *
- * Contains the range and alignment constraints that have to be met during
- * find_empty_resource_slot(). @alignf can be NULL indicating no alignment
- * beyond @align is necessary.
- */
-struct resource_constraint {
-	resource_size_t min, max, align;
-	resource_alignf alignf;
-	void *alignf_data;
-};
-
 static DEFINE_RWLOCK(resource_lock);
 
 static struct resource *next_resource(struct resource *p, bool skip_children)
@@ -651,12 +633,13 @@ next:		if (!this || this->end == root->end)
  * * %0		- if successful, @new members start, end, and flags are altered.
  * * %-EBUSY	- if no empty slot was found.
  */
-static int find_empty_resource_slot(struct resource *root, struct resource *new,
-				    resource_size_t size,
-				    struct resource_constraint *constraint)
+int find_empty_resource_slot(struct resource *root, struct resource *new,
+			     resource_size_t size,
+			     struct resource_constraint *constraint)
 {
 	return  __find_empty_resource_slot(root, NULL, new, size, constraint);
 }
+EXPORT_SYMBOL_GPL(find_empty_resource_slot);
 
 /**
  * reallocate_resource - allocate a slot in the resource tree given range & alignment.
-- 
2.30.2