[PATCH -v4 1/2] MTD: Add __nand_calculate_ecc() to NAND ECC functions

[PATCH -v4 1/2] MTD: Add __nand_calculate_ecc() to NAND ECC functions

[Akinobu Mita]

Add __nand_calculate_ecc() which does not take struct mtd_info.
The built-in 256/512 software ECC calculation and correction tester
will use it.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Cc: linux-mtd@lists.infradead.org
Cc: vimal singh <vimal.newwork@gmail.com>
---
 drivers/mtd/nand/nand_ecc.c  |   25 ++++++++++++++++++++-----
 include/linux/mtd/nand_ecc.h |   10 ++++++++--
 2 files changed, 28 insertions(+), 7 deletions(-)

diff --git a/drivers/mtd/nand/nand_ecc.c b/drivers/mtd/nand/nand_ecc.c
index db7ae9d..809fb53 100644
--- a/drivers/mtd/nand/nand_ecc.c
+++ b/drivers/mtd/nand/nand_ecc.c
@@ -150,20 +150,19 @@ static const char addressbits[256] = {
 };
 
 /**
- * nand_calculate_ecc - [NAND Interface] Calculate 3-byte ECC for 256/512-byte
+ * __nand_calculate_ecc - [NAND Interface] Calculate 3-byte ECC for 256/512-byte
  *			 block
- * @mtd:	MTD block structure
  * @buf:	input buffer with raw data
+ * @eccsize:	data bytes per ecc step (256 or 512)
  * @code:	output buffer with ECC
  */
-int nand_calculate_ecc(struct mtd_info *mtd, const unsigned char *buf,
+void __nand_calculate_ecc(const unsigned char *buf, unsigned int eccsize,
 		       unsigned char *code)
 {
 	int i;
 	const uint32_t *bp = (uint32_t *)buf;
 	/* 256 or 512 bytes/ecc  */
-	const uint32_t eccsize_mult =
-			(((struct nand_chip *)mtd->priv)->ecc.size) >> 8;
+	const uint32_t eccsize_mult = eccsize >> 8;
 	uint32_t cur;		/* current value in buffer */
 	/* rp0..rp15..rp17 are the various accumulated parities (per byte) */
 	uint32_t rp0, rp1, rp2, rp3, rp4, rp5, rp6, rp7;
@@ -412,6 +411,22 @@ int nand_calculate_ecc(struct mtd_info *mtd, const unsigned char *buf,
 		    (invparity[par & 0x55] << 2) |
 		    (invparity[rp17] << 1) |
 		    (invparity[rp16] << 0);
+}
+EXPORT_SYMBOL(__nand_calculate_ecc);
+
+/**
+ * nand_calculate_ecc - [NAND Interface] Calculate 3-byte ECC for 256/512-byte
+ *			 block
+ * @mtd:	MTD block structure
+ * @buf:	input buffer with raw data
+ * @code:	output buffer with ECC
+ */
+int nand_calculate_ecc(struct mtd_info *mtd, const unsigned char *buf,
+		       unsigned char *code)
+{
+	__nand_calculate_ecc(buf,
+			((struct nand_chip *)mtd->priv)->ecc.size, code);
+
 	return 0;
 }
 EXPORT_SYMBOL(nand_calculate_ecc);
diff --git a/include/linux/mtd/nand_ecc.h b/include/linux/mtd/nand_ecc.h
index 052ea8c..41bc013 100644
--- a/include/linux/mtd/nand_ecc.h
+++ b/include/linux/mtd/nand_ecc.h
@@ -16,7 +16,13 @@
 struct mtd_info;
 
 /*
- * Calculate 3 byte ECC code for 256 byte block
+ * Calculate 3 byte ECC code for eccsize byte block
+ */
+void __nand_calculate_ecc(const u_char *dat, unsigned int eccsize,
+				u_char *ecc_code);
+
+/*
+ * Calculate 3 byte ECC code for 256/512 byte block
  */
 int nand_calculate_ecc(struct mtd_info *mtd, const u_char *dat, u_char *ecc_code);
 
@@ -27,7 +33,7 @@ int __nand_correct_data(u_char *dat, u_char *read_ecc, u_char *calc_ecc,
 			unsigned int eccsize);
 
 /*
- * Detect and correct a 1 bit error for 256 byte block
+ * Detect and correct a 1 bit error for 256/512 byte block
  */
 int nand_correct_data(struct mtd_info *mtd, u_char *dat, u_char *read_ecc, u_char *calc_ecc);
 
-- 
1.5.4.3

[PATCH -v4 2/2] MTD: Add nand_ecc test module

[Akinobu Mita]

This module tests NAND ECC functions.

The test is simple.

1. Create a 256 or 512 bytes block of data filled with random bytes (data)
2. Duplicate the data block and inject single bit error (error_data)
3. Try to correct error_data
4. Compare data and error_data

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: linux-mtd@lists.infradead.org
Cc: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Cc: vimal singh <vimal.newwork@gmail.com>
---
 drivers/mtd/tests/Makefile          |    1 +
 drivers/mtd/tests/mtd_nandecctest.c |   87 +++++++++++++++++++++++++++++++++++
 2 files changed, 88 insertions(+), 0 deletions(-)
 create mode 100644 drivers/mtd/tests/mtd_nandecctest.c

diff --git a/drivers/mtd/tests/Makefile b/drivers/mtd/tests/Makefile
index c1d5013..b44dcab 100644
--- a/drivers/mtd/tests/Makefile
+++ b/drivers/mtd/tests/Makefile
@@ -5,3 +5,4 @@ obj-$(CONFIG_MTD_TESTS) += mtd_speedtest.o
 obj-$(CONFIG_MTD_TESTS) += mtd_stresstest.o
 obj-$(CONFIG_MTD_TESTS) += mtd_subpagetest.o
 obj-$(CONFIG_MTD_TESTS) += mtd_torturetest.o
+obj-$(CONFIG_MTD_TESTS) += mtd_nandecctest.o
diff --git a/drivers/mtd/tests/mtd_nandecctest.c b/drivers/mtd/tests/mtd_nandecctest.c
new file mode 100644
index 0000000..c1f3105
--- /dev/null
+++ b/drivers/mtd/tests/mtd_nandecctest.c
@@ -0,0 +1,87 @@
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/random.h>
+#include <linux/string.h>
+#include <linux/bitops.h>
+#include <linux/jiffies.h>
+#include <linux/mtd/nand_ecc.h>
+
+#if defined(CONFIG_MTD_NAND) || defined(CONFIG_MTD_NAND_MODULE)
+
+static void inject_single_bit_error(void *data, size_t size)
+{
+	unsigned long offset = random32() % (size * BITS_PER_BYTE);
+
+	__change_bit(offset, data);
+}
+
+static unsigned char data[512];
+static unsigned char error_data[512];
+
+static int nand_ecc_test(const size_t size)
+{
+	unsigned char code[3];
+	unsigned char error_code[3];
+	char testname[30];
+
+	BUG_ON(sizeof(data) < size);
+
+	sprintf(testname, "nand-ecc-%zu", size);
+
+	get_random_bytes(data, size);
+
+	memcpy(error_data, data, size);
+	inject_single_bit_error(error_data, size);
+
+	__nand_calculate_ecc(data, size, code);
+	__nand_calculate_ecc(error_data, size, error_code);
+	__nand_correct_data(error_data, code, error_code, size);
+
+	if (!memcmp(data, error_data, size)) {
+		printk(KERN_INFO "mtd_nandecctest: ok - %s\n", testname);
+		return 0;
+	}
+
+	printk(KERN_ERR "mtd_nandecctest: not ok - %s\n", testname);
+
+	printk(KERN_DEBUG "hexdump of data:\n");
+	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 16, 4,
+			data, size, false);
+	printk(KERN_DEBUG "hexdump of error data:\n");
+	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 16, 4,
+			error_data, size, false);
+
+	return -1;
+}
+
+#else
+
+static int nand_ecc_test(const size_t size)
+{
+	return 0;
+}
+
+#endif
+
+static int __init ecc_test_init(void)
+{
+	srandom32(jiffies);
+
+	nand_ecc_test(256);
+	nand_ecc_test(512);
+
+	return 0;
+}
+
+static void __exit ecc_test_exit(void)
+{
+}
+
+module_init(ecc_test_init);
+module_exit(ecc_test_exit);
+
+MODULE_DESCRIPTION("NAND ECC function test module");
+MODULE_AUTHOR("Akinobu Mita");
+MODULE_LICENSE("GPL");
-- 
1.5.4.3

Re: [PATCH -v4 1/2] MTD: Add __nand_calculate_ecc() to NAND ECC functions

[Vimal Singh]

Please add my ack:
Acked-by: Vimal Singh <vimalsingh@ti.com>

-vimal

On Thu, Oct 22, 2009 at 1:23 PM, Akinobu Mita <akinobu.mita@gmail.com> wrote:
> Add __nand_calculate_ecc() which does not take struct mtd_info.
> The built-in 256/512 software ECC calculation and correction tester
> will use it.
>
> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
> Cc: David Woodhouse <dwmw2@infradead.org>
> Cc: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
> Cc: linux-mtd@lists.infradead.org
> Cc: vimal singh <vimal.newwork@gmail.com>
> ---
>  drivers/mtd/nand/nand_ecc.c  |   25 ++++++++++++++++++++-----
>  include/linux/mtd/nand_ecc.h |   10 ++++++++--
>  2 files changed, 28 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/mtd/nand/nand_ecc.c b/drivers/mtd/nand/nand_ecc.c
> index db7ae9d..809fb53 100644
> --- a/drivers/mtd/nand/nand_ecc.c
> +++ b/drivers/mtd/nand/nand_ecc.c
> @@ -150,20 +150,19 @@ static const char addressbits[256] = {
>  };
>
>  /**
> - * nand_calculate_ecc - [NAND Interface] Calculate 3-byte ECC for 256/512-byte
> + * __nand_calculate_ecc - [NAND Interface] Calculate 3-byte ECC for 256/512-byte
>  *                      block
> - * @mtd:       MTD block structure
>  * @buf:       input buffer with raw data
> + * @eccsize:   data bytes per ecc step (256 or 512)
>  * @code:      output buffer with ECC
>  */
> -int nand_calculate_ecc(struct mtd_info *mtd, const unsigned char *buf,
> +void __nand_calculate_ecc(const unsigned char *buf, unsigned int eccsize,
>                       unsigned char *code)
>  {
>        int i;
>        const uint32_t *bp = (uint32_t *)buf;
>        /* 256 or 512 bytes/ecc  */
> -       const uint32_t eccsize_mult =
> -                       (((struct nand_chip *)mtd->priv)->ecc.size) >> 8;
> +       const uint32_t eccsize_mult = eccsize >> 8;
>        uint32_t cur;           /* current value in buffer */
>        /* rp0..rp15..rp17 are the various accumulated parities (per byte) */
>        uint32_t rp0, rp1, rp2, rp3, rp4, rp5, rp6, rp7;
> @@ -412,6 +411,22 @@ int nand_calculate_ecc(struct mtd_info *mtd, const unsigned char *buf,
>                    (invparity[par & 0x55] << 2) |
>                    (invparity[rp17] << 1) |
>                    (invparity[rp16] << 0);
> +}
> +EXPORT_SYMBOL(__nand_calculate_ecc);
> +
> +/**
> + * nand_calculate_ecc - [NAND Interface] Calculate 3-byte ECC for 256/512-byte
> + *                      block
> + * @mtd:       MTD block structure
> + * @buf:       input buffer with raw data
> + * @code:      output buffer with ECC
> + */
> +int nand_calculate_ecc(struct mtd_info *mtd, const unsigned char *buf,
> +                      unsigned char *code)
> +{
> +       __nand_calculate_ecc(buf,
> +                       ((struct nand_chip *)mtd->priv)->ecc.size, code);
> +
>        return 0;
>  }
>  EXPORT_SYMBOL(nand_calculate_ecc);
> diff --git a/include/linux/mtd/nand_ecc.h b/include/linux/mtd/nand_ecc.h
> index 052ea8c..41bc013 100644
> --- a/include/linux/mtd/nand_ecc.h
> +++ b/include/linux/mtd/nand_ecc.h
> @@ -16,7 +16,13 @@
>  struct mtd_info;
>
>  /*
> - * Calculate 3 byte ECC code for 256 byte block
> + * Calculate 3 byte ECC code for eccsize byte block
> + */
> +void __nand_calculate_ecc(const u_char *dat, unsigned int eccsize,
> +                               u_char *ecc_code);
> +
> +/*
> + * Calculate 3 byte ECC code for 256/512 byte block
>  */
>  int nand_calculate_ecc(struct mtd_info *mtd, const u_char *dat, u_char *ecc_code);
>
> @@ -27,7 +33,7 @@ int __nand_correct_data(u_char *dat, u_char *read_ecc, u_char *calc_ecc,
>                        unsigned int eccsize);
>
>  /*
> - * Detect and correct a 1 bit error for 256 byte block
> + * Detect and correct a 1 bit error for 256/512 byte block
>  */
>  int nand_correct_data(struct mtd_info *mtd, u_char *dat, u_char *read_ecc, u_char *calc_ecc);
>
> --
> 1.5.4.3
>
>

Re: [PATCH -v4 1/2] MTD: Add __nand_calculate_ecc() to NAND ECC functions

[Artem Bityutskiy]

On Thu, 2009-10-22 at 13:57 +0530, Vimal Singh wrote:
> Please add my ack:
> Acked-by: Vimal Singh <vimalsingh@ti.com>
> 

Yes, applied to my l2 tree and added your ack.

-- 
Best Regards,
Artem Bityutskiy (Артём Битюцкий)