From 95099d4622f8cb224d94e314c7a8e0df60b13f87 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Sat, 09 Dec 2023 08:38:01 +0000
Subject: [PATCH] enable docker ppp

---
 kernel/drivers/mtd/mtdconcat.c |  132 +++++++++++++++++++++++++++++---------------
 1 files changed, 87 insertions(+), 45 deletions(-)

diff --git a/kernel/drivers/mtd/mtdconcat.c b/kernel/drivers/mtd/mtdconcat.c
index cbc5925..f685a58 100644
--- a/kernel/drivers/mtd/mtdconcat.c
+++ b/kernel/drivers/mtd/mtdconcat.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * MTD device concatenation layer
  *
@@ -5,21 +6,6 @@
  * Copyright © 2002-2010 David Woodhouse <dwmw2@infradead.org>
  *
  * NAND support by Christian Gan <cgan@iders.ca>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
- *
  */
 
 #include <linux/kernel.h>
@@ -115,6 +101,47 @@
 	}
 	return -EINVAL;
 }
+
+static int
+concat_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
+	     size_t * retlen, const u_char * buf)
+{
+	struct mtd_concat *concat = CONCAT(mtd);
+	int err = -EINVAL;
+	int i;
+	for (i = 0; i < concat->num_subdev; i++) {
+		struct mtd_info *subdev = concat->subdev[i];
+		size_t size, retsize;
+
+		if (to >= subdev->size) {
+			to -= subdev->size;
+			continue;
+		}
+		if (to + len > subdev->size)
+			size = subdev->size - to;
+		else
+			size = len;
+
+		err = mtd_panic_write(subdev, to, size, &retsize, buf);
+		if (err == -EOPNOTSUPP) {
+			printk(KERN_ERR "mtdconcat: Cannot write from panic without panic_write\n");
+			return err;
+		}
+		if (err)
+			break;
+
+		*retlen += retsize;
+		len -= size;
+		if (len == 0)
+			break;
+
+		err = -EINVAL;
+		buf += size;
+		to = 0;
+	}
+	return err;
+}
+
 
 static int
 concat_write(struct mtd_info *mtd, loff_t to, size_t len,
@@ -451,7 +478,8 @@
 	return err;
 }
 
-static int concat_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
+static int concat_xxlock(struct mtd_info *mtd, loff_t ofs, uint64_t len,
+			 bool is_lock)
 {
 	struct mtd_concat *concat = CONCAT(mtd);
 	int i, err = -EINVAL;
@@ -470,7 +498,10 @@
 		else
 			size = len;
 
-		err = mtd_lock(subdev, ofs, size);
+		if (is_lock)
+			err = mtd_lock(subdev, ofs, size);
+		else
+			err = mtd_unlock(subdev, ofs, size);
 		if (err)
 			break;
 
@@ -485,35 +516,33 @@
 	return err;
 }
 
+static int concat_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
+{
+	return concat_xxlock(mtd, ofs, len, true);
+}
+
 static int concat_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 {
+	return concat_xxlock(mtd, ofs, len, false);
+}
+
+static int concat_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
+{
 	struct mtd_concat *concat = CONCAT(mtd);
-	int i, err = 0;
+	int i, err = -EINVAL;
 
 	for (i = 0; i < concat->num_subdev; i++) {
 		struct mtd_info *subdev = concat->subdev[i];
-		uint64_t size;
 
 		if (ofs >= subdev->size) {
-			size = 0;
 			ofs -= subdev->size;
 			continue;
 		}
+
 		if (ofs + len > subdev->size)
-			size = subdev->size - ofs;
-		else
-			size = len;
-
-		err = mtd_unlock(subdev, ofs, size);
-		if (err)
 			break;
 
-		len -= size;
-		if (len == 0)
-			break;
-
-		err = -EINVAL;
-		ofs = 0;
+		return mtd_is_locked(subdev, ofs, len);
 	}
 
 	return err;
@@ -612,6 +641,7 @@
 	int i;
 	size_t size;
 	struct mtd_concat *concat;
+	struct mtd_info *subdev_master = NULL;
 	uint32_t max_erasesize, curr_erasesize;
 	int num_erase_region;
 	int max_writebufsize = 0;
@@ -650,16 +680,24 @@
 	concat->mtd.subpage_sft = subdev[0]->subpage_sft;
 	concat->mtd.oobsize = subdev[0]->oobsize;
 	concat->mtd.oobavail = subdev[0]->oobavail;
-	if (subdev[0]->_writev)
+
+	subdev_master = mtd_get_master(subdev[0]);
+	if (subdev_master->_writev)
 		concat->mtd._writev = concat_writev;
-	if (subdev[0]->_read_oob)
+	if (subdev_master->_read_oob)
 		concat->mtd._read_oob = concat_read_oob;
-	if (subdev[0]->_write_oob)
+	if (subdev_master->_write_oob)
 		concat->mtd._write_oob = concat_write_oob;
-	if (subdev[0]->_block_isbad)
+	if (subdev_master->_block_isbad)
 		concat->mtd._block_isbad = concat_block_isbad;
-	if (subdev[0]->_block_markbad)
+	if (subdev_master->_block_markbad)
 		concat->mtd._block_markbad = concat_block_markbad;
+	if (subdev_master->_panic_write)
+		concat->mtd._panic_write = concat_panic_write;
+	if (subdev_master->_read)
+		concat->mtd._read = concat_read;
+	if (subdev_master->_write)
+		concat->mtd._write = concat_write;
 
 	concat->mtd.ecc_stats.badblocks = subdev[0]->ecc_stats.badblocks;
 
@@ -690,14 +728,22 @@
 				    subdev[i]->flags & MTD_WRITEABLE;
 		}
 
+		subdev_master = mtd_get_master(subdev[i]);
 		concat->mtd.size += subdev[i]->size;
 		concat->mtd.ecc_stats.badblocks +=
 			subdev[i]->ecc_stats.badblocks;
 		if (concat->mtd.writesize   !=  subdev[i]->writesize ||
 		    concat->mtd.subpage_sft != subdev[i]->subpage_sft ||
 		    concat->mtd.oobsize    !=  subdev[i]->oobsize ||
-		    !concat->mtd._read_oob  != !subdev[i]->_read_oob ||
-		    !concat->mtd._write_oob != !subdev[i]->_write_oob) {
+		    !concat->mtd._read_oob  != !subdev_master->_read_oob ||
+		    !concat->mtd._write_oob != !subdev_master->_write_oob) {
+			/*
+			 * Check against subdev[i] for data members, because
+			 * subdev's attributes may be different from master
+			 * mtd device. Check against subdev's master mtd
+			 * device for callbacks, because the existence of
+			 * subdev's callbacks is decided by master mtd device.
+			 */
 			kfree(concat);
 			printk("Incompatible OOB or ECC data on \"%s\"\n",
 			       subdev[i]->name);
@@ -713,11 +759,10 @@
 	concat->mtd.name = name;
 
 	concat->mtd._erase = concat_erase;
-	concat->mtd._read = concat_read;
-	concat->mtd._write = concat_write;
 	concat->mtd._sync = concat_sync;
 	concat->mtd._lock = concat_lock;
 	concat->mtd._unlock = concat_unlock;
+	concat->mtd._is_locked = concat_is_locked;
 	concat->mtd._suspend = concat_suspend;
 	concat->mtd._resume = concat_resume;
 
@@ -852,10 +897,7 @@
 	return &concat->mtd;
 }
 
-/*
- * This function destroys an MTD object obtained from concat_mtd_devs()
- */
-
+/* Cleans the context obtained from mtd_concat_create() */
 void mtd_concat_destroy(struct mtd_info *mtd)
 {
 	struct mtd_concat *concat = CONCAT(mtd);

--
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