openwrt/target/linux/generic/pending-4.19/161-mtd-part-add-generic-parsing-of-linux-part-probe.patch

From: Hauke Mehrtens <[email protected]>
Subject: mtd: part: add generic parsing of linux,part-probe

This moves the linux,part-probe device tree parsing code from
physmap_of.c to mtdpart.c. Now all drivers can use this feature by just
providing a reference to their device tree node in struct
mtd_part_parser_data.

THIS METHOD HAS BEEN DEPRECATED

Linux supports "compatible" property in the "partitions" subnode now. It
should be used to specify partitions format (and trigger proper parser
usage) if needed.

Signed-off-by: Hauke Mehrtens <[email protected]>
---
 Documentation/devicetree/bindings/mtd/nand.txt | 16 +++++++++
 drivers/mtd/maps/physmap_of.c                  | 46 +-------------------------
 drivers/mtd/mtdpart.c                          | 45 +++++++++++++++++++++++++
 3 files changed, 62 insertions(+), 45 deletions(-)

--- a/Documentation/devicetree/bindings/mtd/nand.txt
+++ b/Documentation/devicetree/bindings/mtd/nand.txt
@@ -49,6 +49,22 @@ Optional NAND chip properties:
 
 - nand-rb: shall contain the native Ready/Busy ids.
 
+- linux,part-probe: list of name as strings of the partition parser
+		    which should be used to parse the partition table.
+		    They will be tried in the specified ordering and
+		    the next one will be used if the previous one
+		    failed.
+
+		    Example: linux,part-probe = "cmdlinepart", "ofpart";
+
+		    This is also the default value, which will be used
+		    if this attribute is not specified. It could be
+		    that the flash driver in use overwrote the default
+		    value and uses some other default.
+
+		    Possible values are: bcm47xxpart, afs, ar7part,
+		    ofoldpart, ofpart, bcm63xxpart, RedBoot, cmdlinepart
+
 The ECC strength and ECC step size properties define the correction capability
 of a controller. Together, they say a controller can correct "{strength} bit
 errors per {size} bytes".
--- a/drivers/mtd/maps/physmap_of_core.c
+++ b/drivers/mtd/maps/physmap_of_core.c
@@ -115,37 +115,9 @@ static struct mtd_info *obsolete_probe(s
 static const char * const part_probe_types_def[] = {
 	"cmdlinepart", "RedBoot", "ofpart", "ofoldpart", NULL };
 
-static const char * const *of_get_probes(struct device_node *dp)
-{
-	const char **res;
-	int count;
-
-	count = of_property_count_strings(dp, "linux,part-probe");
-	if (count < 0)
-		return part_probe_types_def;
-
-	res = kcalloc(count + 1, sizeof(*res), GFP_KERNEL);
-	if (!res)
-		return NULL;
-
-	count = of_property_read_string_array(dp, "linux,part-probe", res,
-					      count);
-	if (count < 0)
-		return NULL;
-
-	return res;
-}
-
-static void of_free_probes(const char * const *probes)
-{
-	if (probes != part_probe_types_def)
-		kfree(probes);
-}
-
 static const struct of_device_id of_flash_match[];
 static int of_flash_probe(struct platform_device *dev)
 {
-	const char * const *part_probe_types;
 	const struct of_device_id *match;
 	struct device_node *dp = dev->dev.of_node;
 	struct resource res;
@@ -316,14 +288,8 @@ static int of_flash_probe(struct platfor
 
 	info->cmtd->dev.parent = &dev->dev;
 	mtd_set_of_node(info->cmtd, dp);
-	part_probe_types = of_get_probes(dp);
-	if (!part_probe_types) {
-		err = -ENOMEM;
-		goto err_out;
-	}
-	mtd_device_parse_register(info->cmtd, part_probe_types, NULL,
+	mtd_device_parse_register(info->cmtd, part_probe_types_def, NULL,
 			NULL, 0);
-	of_free_probes(part_probe_types);
 
 	kfree(mtd_list);
 
--- a/drivers/mtd/mtdpart.c
+++ b/drivers/mtd/mtdpart.c
@@ -29,6 +29,7 @@
 #include <linux/kmod.h>
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/partitions.h>
+#include <linux/of.h>
 #include <linux/err.h>
 #include <linux/of.h>
 
@@ -796,6 +797,37 @@ void deregister_mtd_parser(struct mtd_pa
 }
 EXPORT_SYMBOL_GPL(deregister_mtd_parser);
 
+#include <linux/version.h>
+
+/*
+ * Parses the linux,part-probe device tree property.
+ * When a non null value is returned it has to be freed with kfree() by
+ * the caller.
+ */
+static const char * const *of_get_probes(struct device_node *dp)
+{
+	const char **res;
+	int count;
+
+	count = of_property_count_strings(dp, "linux,part-probe");
+	if (count < 0)
+		return NULL;
+
+	res = kzalloc((count + 1) * sizeof(*res), GFP_KERNEL);
+	if (!res)
+		return NULL;
+
+	count = of_property_read_string_array(dp, "linux,part-probe", res,
+					      count);
+	if (count < 0)
+		return NULL;
+
+	pr_warn("Support for the generic \"linux,part-probe\" has been deprecated and will be removed soon");
+	BUILD_BUG_ON(LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0));
+
+	return res;
+}
+
 /*
  * Do not forget to update 'parse_mtd_partitions()' kerneldoc comment if you
  * are changing this array!
@@ -948,6 +980,13 @@ int parse_mtd_partitions(struct mtd_info
 	struct mtd_partitions pparts = { };
 	struct mtd_part_parser *parser;
 	int ret, err = 0;
+	const char *const *types_of = NULL;
+
+	if (mtd_get_of_node(master)) {
+		types_of = of_get_probes(mtd_get_of_node(master));
+		if (types_of != NULL)
+			types = types_of;
+	}
 
 	if (!types)
 		types = mtd_is_partition(master) ? default_subpartition_types :
@@ -989,6 +1028,7 @@ int parse_mtd_partitions(struct mtd_info
 		if (ret < 0 && !err)
 			err = ret;
 	}
+	kfree(types_of);
 	return err;
 }