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Commit abf3c0f2 authored by Kyungmin Park's avatar Kyungmin Park
Browse files

[MTD] OneNAND: Reduce internal BufferRAM operations 



It use blockpage instead of a pair (block, page). It can also cover a small chunk access. 0x00, 0x20, 0x40 and so on.

And in JFFS2 behavior, sometimes it reads two pages alternatively.
e.g., It first reads A page, B page and A page.
So we check another bufferram to find requested page.

Signed-off-by: default avatarKyungmin Park <kyungmin.park@samsung.com>
parent 4f4fad27

drivers/mtd/onenand/onenand_base.c

+23 −24
Original line number Diff line number Diff line
@@ -577,19 +577,22 @@ static int onenand_write_bufferram(struct mtd_info *mtd, int area, 
static int onenand_check_bufferram(struct mtd_info *mtd, loff_t addr)

{

	struct onenand_chip *this = mtd->priv;

	int block, page;

	int i;

	int blockpage;

	unsigned int i;



	block = (int) (addr >> this->erase_shift);

	page = (int) (addr >> this->page_shift) & this->page_mask;

	blockpage = (int) (addr >> this->page_shift);



	/* Is there valid data? */

	i = ONENAND_CURRENT_BUFFERRAM(this);

	if (this->bufferram[i].blockpage == blockpage)

		return 1;



	/* Is there valid data? */

	if (this->bufferram[i].block == block &&

	    this->bufferram[i].page == page &&

	    this->bufferram[i].valid)

	/* Check another BufferRAM */

	i = ONENAND_NEXT_BUFFERRAM(this);

	if (this->bufferram[i].blockpage == blockpage) {

		ONENAND_SET_NEXT_BUFFERRAM(this);

		return 1;

	}



	return 0;

}
@@ -602,30 +605,26 @@ static int onenand_check_bufferram(struct mtd_info *mtd, loff_t addr) 
 *

 * Update BufferRAM information

 */

static int onenand_update_bufferram(struct mtd_info *mtd, loff_t addr,

static void onenand_update_bufferram(struct mtd_info *mtd, loff_t addr,

		int valid)

{

	struct onenand_chip *this = mtd->priv;

	int block, page;

	int i;

	int blockpage;

	unsigned int i;



	block = (int) (addr >> this->erase_shift);

	page = (int) (addr >> this->page_shift) & this->page_mask;

	blockpage = (int) (addr >> this->page_shift);



	/* Invalidate BufferRAM */

	for (i = 0; i < MAX_BUFFERRAM; i++) {

		if (this->bufferram[i].block == block &&

		    this->bufferram[i].page == page)

			this->bufferram[i].valid = 0;

	}

	/* Invalidate another BufferRAM */

	i = ONENAND_NEXT_BUFFERRAM(this);

	if (this->bufferram[i].blockpage == blockpage) {

		this->bufferram[i].blockpage = -1;



	/* Update BufferRAM */

	i = ONENAND_CURRENT_BUFFERRAM(this);

	this->bufferram[i].block = block;

	this->bufferram[i].page = page;

	this->bufferram[i].valid = valid;



	return 0;

	if (valid)

		this->bufferram[i].blockpage = blockpage;

	else

		this->bufferram[i].blockpage = -1;

}



/**

include/linux/mtd/onenand.h

+2 −6
Original line number Diff line number Diff line
@@ -42,14 +42,10 @@ typedef enum { 


/**

 * struct onenand_bufferram - OneNAND BufferRAM Data

 * @block:		block address in BufferRAM

 * @page:		page address in BufferRAM

 * @valid:		valid flag

 * @blockpage:		block & page address in BufferRAM

 */

struct onenand_bufferram {

	int block;

	int page;

	int valid;

	int	blockpage;

};



/**