From a67b3719f32673a9890700c72b980acbd2749e49 Mon Sep 17 00:00:00 2001
From: Marek Behún
Date: Tue, 5 Oct 2021 15:56:01 +0200
Subject: mtd: spi-flash: Check for zero length in legacy spi_flash_*()

Check for zero length in the legacy spi_flash_read() /
spi_flash_write() / spi_flash_erase() functions.
On zero length, return 0 immediately, don't call the underlying method.

Rationale:
- these legacy functions call the _read(), _write() and _erase() methods
  of struct mtd
- the DM callers of these methods already check for zero length
- making all callers of these methods check for zero length makes it
  possible to remove the check from implementations of these _read(),
  _write() and _erase() methods

Signed-off-by: Marek Behún <marek.behun@nic.cz>
---
 include/spi_flash.h | 9 +++++++++
 1 file changed, 9 insertions(+)

(limited to 'include')

diff --git a/include/spi_flash.h b/include/spi_flash.h
index 3d747c925b9..4d4ae89c192 100644
--- a/include/spi_flash.h
+++ b/include/spi_flash.h
@@ -165,6 +165,9 @@ static inline int spi_flash_read(struct spi_flash *flash, u32 offset,
 	struct mtd_info *mtd = &flash->mtd;
 	size_t retlen;
 
+	if (!len)
+		return 0;
+
 	return mtd->_read(mtd, offset, len, &retlen, buf);
 }
 
@@ -174,6 +177,9 @@ static inline int spi_flash_write(struct spi_flash *flash, u32 offset,
 	struct mtd_info *mtd = &flash->mtd;
 	size_t retlen;
 
+	if (!len)
+		return 0;
+
 	return mtd->_write(mtd, offset, len, &retlen, buf);
 }
 
@@ -188,6 +194,9 @@ static inline int spi_flash_erase(struct spi_flash *flash, u32 offset,
 		return -EINVAL;
 	}
 
+	if (!len)
+		return 0;
+
 	memset(&instr, 0, sizeof(instr));
 	instr.addr = offset;
 	instr.len = len;
-- 
cgit v1.2.3


From 0d1ecc99cb59c2190257f7738f91db21f174dc02 Mon Sep 17 00:00:00 2001
From: Marek Behún
Date: Tue, 5 Oct 2021 15:56:06 +0200
Subject: mtd: Remove mtd_erase_callback() entirely

The original purpose of mtd_erase_callback() in Linux at the time it was
imported to U-Boot, was to inform the caller that erasing is done (since
it was an asynchronous operation).

All supplied callback methods in U-Boot do nothing, but the
mtd_erase_callback() function was (until previous patch) grossly abused
in U-Boot's mtdpart implementation for completely different purpose.

Since we got rid of the abusement, remove the mtd_erase_callback()
function and the .callback member from struct erase_info entirely, in
order to avoid such problems in the future.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
---
 cmd/onenand.c                      |  9 ++-------
 drivers/mtd/altera_qspi.c          |  3 ---
 drivers/mtd/cfi_mtd.c              |  1 -
 drivers/mtd/mtdconcat.c            | 11 -----------
 drivers/mtd/mtdcore.c              |  8 --------
 drivers/mtd/mtdpart.c              | 21 ---------------------
 drivers/mtd/nand/raw/nand_base.c   |  4 ----
 drivers/mtd/onenand/onenand_base.c |  3 ---
 drivers/mtd/spi/sf_mtd.c           |  1 -
 drivers/mtd/spi/spi-nor-core.c     |  5 ++---
 drivers/mtd/ubi/io.c               | 13 -------------
 env/onenand.c                      |  4 +---
 fs/yaffs2/yaffs_mtdif.c            |  1 -
 include/linux/mtd/mtd.h            | 11 -----------
 include/nand.h                     |  1 -
 15 files changed, 5 insertions(+), 91 deletions(-)

(limited to 'include')

diff --git a/cmd/onenand.c b/cmd/onenand.c
index 852ed5c7b21..592985a7ee3 100644
--- a/cmd/onenand.c
+++ b/cmd/onenand.c
@@ -186,9 +186,7 @@ next:
 static int onenand_block_erase(u32 start, u32 size, int force)
 {
 	struct onenand_chip *this = mtd->priv;
-	struct erase_info instr = {
-		.callback	= NULL,
-	};
+	struct erase_info instr = {};
 	loff_t ofs;
 	int ret;
 	int blocksize = 1 << this->erase_shift;
@@ -219,10 +217,7 @@ static int onenand_block_erase(u32 start, u32 size, int force)
 static int onenand_block_test(u32 start, u32 size)
 {
 	struct onenand_chip *this = mtd->priv;
-	struct erase_info instr = {
-		.callback	= NULL,
-		.priv		= 0,
-	};
+	struct erase_info instr = {};
 
 	int blocks;
 	loff_t ofs;
diff --git a/drivers/mtd/altera_qspi.c b/drivers/mtd/altera_qspi.c
index 7bac599a54a..d31391f36a4 100644
--- a/drivers/mtd/altera_qspi.c
+++ b/drivers/mtd/altera_qspi.c
@@ -153,7 +153,6 @@ static int altera_qspi_erase(struct mtd_info *mtd, struct erase_info *instr)
 				putc('\n');
 			instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
 			instr->state = MTD_ERASE_FAILED;
-			mtd_erase_callback(instr);
 			return -EIO;
 		}
 		flash = pdata->base + addr;
@@ -177,7 +176,6 @@ static int altera_qspi_erase(struct mtd_info *mtd, struct erase_info *instr)
 				writel(stat, &regs->isr); /* clear isr */
 				instr->fail_addr = addr;
 				instr->state = MTD_ERASE_FAILED;
-				mtd_erase_callback(instr);
 				return -EIO;
 			}
 			if (flash_verbose)
@@ -189,7 +187,6 @@ static int altera_qspi_erase(struct mtd_info *mtd, struct erase_info *instr)
 		addr += mtd->erasesize;
 	}
 	instr->state = MTD_ERASE_DONE;
-	mtd_erase_callback(instr);
 
 	return 0;
 }
diff --git a/drivers/mtd/cfi_mtd.c b/drivers/mtd/cfi_mtd.c
index 78293caa2f7..2295bb7220b 100644
--- a/drivers/mtd/cfi_mtd.c
+++ b/drivers/mtd/cfi_mtd.c
@@ -58,7 +58,6 @@ static int cfi_mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
 		}
 
 		instr->state = MTD_ERASE_DONE;
-		mtd_erase_callback(instr);
 		return 0;
 	}
 
diff --git a/drivers/mtd/mtdconcat.c b/drivers/mtd/mtdconcat.c
index 684bc949985..af3c4765c4d 100644
--- a/drivers/mtd/mtdconcat.c
+++ b/drivers/mtd/mtdconcat.c
@@ -338,14 +338,6 @@ concat_write_oob(struct mtd_info *mtd, loff_t to, struct mtd_oob_ops *ops)
 	return -EINVAL;
 }
 
-static void concat_erase_callback(struct erase_info *instr)
-{
-	/* Nothing to do here in U-Boot */
-#ifndef __UBOOT__
-	wake_up((wait_queue_head_t *) instr->priv);
-#endif
-}
-
 static int concat_dev_erase(struct mtd_info *mtd, struct erase_info *erase)
 {
 	int err;
@@ -358,7 +350,6 @@ static int concat_dev_erase(struct mtd_info *mtd, struct erase_info *erase)
 	init_waitqueue_head(&waitq);
 
 	erase->mtd = mtd;
-	erase->callback = concat_erase_callback;
 	erase->priv = (unsigned long) &waitq;
 
 	/*
@@ -498,8 +489,6 @@ static int concat_erase(struct mtd_info *mtd, struct erase_info *instr)
 	if (err)
 		return err;
 
-	if (instr->callback)
-		instr->callback(instr);
 	return 0;
 }
 
diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 9496903e861..1d45fb55c72 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -906,13 +906,6 @@ void __put_mtd_device(struct mtd_info *mtd)
 }
 EXPORT_SYMBOL_GPL(__put_mtd_device);
 
-/*
- * Erase is an asynchronous operation.  Device drivers are supposed
- * to call instr->callback() whenever the operation completes, even
- * if it completes with a failure.
- * Callers are supposed to pass a callback function and wait for it
- * to be called before writing to the block.
- */
 int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
 {
 	if (instr->addr > mtd->size || instr->len > mtd->size - instr->addr)
@@ -922,7 +915,6 @@ int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
 	instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
 	if (!instr->len) {
 		instr->state = MTD_ERASE_DONE;
-		mtd_erase_callback(instr);
 		return 0;
 	}
 	return mtd->_erase(mtd, instr);
diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
index 6ab481a7b1c..a435ce6d079 100644
--- a/drivers/mtd/mtdpart.c
+++ b/drivers/mtd/mtdpart.c
@@ -456,27 +456,6 @@ static int part_erase(struct mtd_info *mtd, struct erase_info *instr)
 	return ret;
 }
 
-void mtd_erase_callback(struct erase_info *instr)
-{
-	if (!instr->callback)
-		return;
-
-	if (instr->mtd->_erase == part_erase && instr->len) {
-		if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
-			instr->fail_addr -= instr->mtd->offset;
-		instr->addr -= instr->mtd->offset;
-	}
-
-	instr->callback(instr);
-
-	if (instr->mtd->_erase == part_erase && instr->len) {
-		if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
-			instr->fail_addr += instr->mtd->offset;
-		instr->addr += instr->mtd->offset;
-	}
-}
-EXPORT_SYMBOL_GPL(mtd_erase_callback);
-
 static int part_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 {
 	return mtd->parent->_lock(mtd->parent, ofs + mtd->offset, len);
diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c
index b533683dfe6..f7616985d95 100644
--- a/drivers/mtd/nand/raw/nand_base.c
+++ b/drivers/mtd/nand/raw/nand_base.c
@@ -3602,10 +3602,6 @@ erase_exit:
 	chip->select_chip(mtd, -1);
 	nand_release_device(mtd);
 
-	/* Do call back function */
-	if (!ret)
-		mtd_erase_callback(instr);
-
 	/* Return more or less happy */
 	return ret;
 }
diff --git a/drivers/mtd/onenand/onenand_base.c b/drivers/mtd/onenand/onenand_base.c
index 46aeef258d9..56e1858de45 100644
--- a/drivers/mtd/onenand/onenand_base.c
+++ b/drivers/mtd/onenand/onenand_base.c
@@ -1836,9 +1836,6 @@ int onenand_erase(struct mtd_info *mtd, struct erase_info *instr)
 erase_exit:
 
 	ret = instr->state == MTD_ERASE_DONE ? 0 : -EIO;
-	/* Do call back function */
-	if (!ret)
-		mtd_erase_callback(instr);
 
 	/* Deselect and wake up anyone waiting on the device */
 	onenand_release_device(mtd);
diff --git a/drivers/mtd/spi/sf_mtd.c b/drivers/mtd/spi/sf_mtd.c
index 04de8680809..0aed28a52b7 100644
--- a/drivers/mtd/spi/sf_mtd.c
+++ b/drivers/mtd/spi/sf_mtd.c
@@ -46,7 +46,6 @@ static int spi_flash_mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
 	}
 
 	instr->state = MTD_ERASE_DONE;
-	mtd_erase_callback(instr);
 
 	return 0;
 }
diff --git a/drivers/mtd/spi/spi-nor-core.c b/drivers/mtd/spi/spi-nor-core.c
index a85759967b0..4388a08a90d 100644
--- a/drivers/mtd/spi/spi-nor-core.c
+++ b/drivers/mtd/spi/spi-nor-core.c
@@ -918,7 +918,7 @@ static int spi_nor_erase(struct mtd_info *mtd, struct erase_info *instr)
 	div_u64_rem(instr->len, mtd->erasesize, &rem);
 	if (rem) {
 		ret = -EINVAL;
-		goto erase_err_callback;
+		goto err;
 	}
 
 	addr = instr->addr;
@@ -966,14 +966,13 @@ erase_err:
 	if (!ret)
 		ret = err;
 
-erase_err_callback:
+err:
 	if (ret) {
 		instr->fail_addr = addr_known ? addr : MTD_FAIL_ADDR_UNKNOWN;
 		instr->state = MTD_ERASE_FAILED;
 	} else {
 		instr->state = MTD_ERASE_DONE;
 	}
-	mtd_erase_callback(instr);
 
 	return ret;
 }
diff --git a/drivers/mtd/ubi/io.c b/drivers/mtd/ubi/io.c
index b8b878b9182..14be95b74bc 100644
--- a/drivers/mtd/ubi/io.c
+++ b/drivers/mtd/ubi/io.c
@@ -304,18 +304,6 @@ int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
 	return err;
 }
 
-/**
- * erase_callback - MTD erasure call-back.
- * @ei: MTD erase information object.
- *
- * Note, even though MTD erase interface is asynchronous, all the current
- * implementations are synchronous anyway.
- */
-static void erase_callback(struct erase_info *ei)
-{
-	wake_up_interruptible((wait_queue_head_t *)ei->priv);
-}
-
 /**
  * do_sync_erase - synchronously erase a physical eraseblock.
  * @ubi: UBI device description object
@@ -346,7 +334,6 @@ retry:
 	ei.mtd      = ubi->mtd;
 	ei.addr     = (loff_t)pnum * ubi->peb_size;
 	ei.len      = ubi->peb_size;
-	ei.callback = erase_callback;
 	ei.priv     = (unsigned long)&wq;
 
 	err = mtd_erase(ubi->mtd, &ei);
diff --git a/env/onenand.c b/env/onenand.c
index c8da3ff8114..1faa2cb62a3 100644
--- a/env/onenand.c
+++ b/env/onenand.c
@@ -73,9 +73,7 @@ static int env_onenand_save(void)
 #endif
 	loff_t	env_addr = CONFIG_ENV_ADDR;
 	size_t	retlen;
-	struct erase_info instr = {
-		.callback	= NULL,
-	};
+	struct erase_info instr = {};
 
 	ret = env_export(&env_new);
 	if (ret)
diff --git a/fs/yaffs2/yaffs_mtdif.c b/fs/yaffs2/yaffs_mtdif.c
index d338f9aa918..50fed2d4b15 100644
--- a/fs/yaffs2/yaffs_mtdif.c
+++ b/fs/yaffs2/yaffs_mtdif.c
@@ -145,7 +145,6 @@ int nandmtd_EraseBlockInNAND(struct yaffs_dev *dev, int blockNumber)
 	ei.len = dev->data_bytes_per_chunk * dev->param.chunks_per_block;
 	ei.time = 1000;
 	ei.retries = 2;
-	ei.callback = NULL;
 	ei.priv = (u_long) dev;
 
 	/* Todo finish off the ei if required */
diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h
index 3b302fb8c31..74554009815 100644
--- a/include/linux/mtd/mtd.h
+++ b/include/linux/mtd/mtd.h
@@ -51,7 +51,6 @@ struct erase_info {
 	u_long retries;
 	unsigned dev;
 	unsigned cell;
-	void (*callback) (struct erase_info *self);
 	u_long priv;
 	u_char state;
 	struct erase_info *next;
@@ -535,16 +534,6 @@ extern int unregister_mtd_user (struct mtd_notifier *old);
 #endif
 void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size);
 
-#ifdef CONFIG_MTD_PARTITIONS
-void mtd_erase_callback(struct erase_info *instr);
-#else
-static inline void mtd_erase_callback(struct erase_info *instr)
-{
-	if (instr->callback)
-		instr->callback(instr);
-}
-#endif
-
 static inline int mtd_is_bitflip(int err) {
 	return err == -EUCLEAN;
 }
diff --git a/include/nand.h b/include/nand.h
index 75c605193ab..09dbda4e81b 100644
--- a/include/nand.h
+++ b/include/nand.h
@@ -69,7 +69,6 @@ static inline int nand_erase(struct mtd_info *info, loff_t off, size_t size)
 	instr.mtd = info;
 	instr.addr = off;
 	instr.len = size;
-	instr.callback = 0;
 
 	return mtd_erase(info, &instr);
 }
-- 
cgit v1.2.3