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Commit d086d436 authored by Vijay Kumar's avatar Vijay Kumar Committed by David Woodhouse
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[MTD] NAND: nandsim page-wise allocation (2/2) 



For page wise allocation, an array of flash page pointers is allocated
during initialization. The flash pages are themselves allocated when a
write occurs to the page. The flash pages are deallocated when they
are erased.

Signed-off-by: default avatarVijay Kumar <vijaykumar@bravegnu.org>
Signed-off-by: default avatarDavid Woodhouse <dwmw2@infradead.org>
parent 47e37743

drivers/mtd/nand/nandsim.c

+138 −24
Original line number Diff line number Diff line
@@ -226,6 +226,14 @@ MODULE_PARM_DESC(dbg, "Output debug information if not zero"); 
 */

#define NS_MAX_PREVSTATES 1



/*

 * A union to represent flash memory contents and flash buffer.

 */

union ns_mem {

	u_char *byte;    /* for byte access */

	uint16_t *word;  /* for 16-bit word access */

};



/*

 * The structure which describes all the internal simulator data.

 */
@@ -243,17 +251,11 @@ struct nandsim { 
	uint16_t npstates;      /* number of previous states saved */

	uint16_t stateidx;      /* current state index */



	/* The simulated NAND flash image */

	union flash_media {

		u_char *byte;

		uint16_t    *word;

	} mem;

	/* The simulated NAND flash pages array */

	union ns_mem *pages;



	/* Internal buffer of page + OOB size bytes */

	union internal_buffer {

		u_char *byte;    /* for byte access */

		uint16_t *word;  /* for 16-bit word access */

	} buf;

	union ns_mem buf;



	/* NAND flash "geometry" */

	struct nandsin_geometry {
@@ -341,6 +343,46 @@ static struct mtd_info *nsmtd; 


static u_char ns_verify_buf[NS_LARGEST_PAGE_SIZE];



/*

 * Allocate array of page pointers and initialize the array to NULL

 * pointers.

 *

 * RETURNS: 0 if success, -ENOMEM if memory alloc fails.

 */

static int

alloc_device(struct nandsim *ns)

{

	int i;



	ns->pages = vmalloc(ns->geom.pgnum * sizeof(union ns_mem));

	if (!ns->pages) {

		NS_ERR("alloc_map: unable to allocate page array\n");

		return -ENOMEM;

	}

	for (i = 0; i < ns->geom.pgnum; i++) {

		ns->pages[i].byte = NULL;

	}



	return 0;

}



/*

 * Free any allocated pages, and free the array of page pointers.

 */

static void

free_device(struct nandsim *ns)

{

	int i;



	if (ns->pages) {

		for (i = 0; i < ns->geom.pgnum; i++) {

			if (ns->pages[i].byte)

				kfree(ns->pages[i].byte);

		}

		vfree(ns->pages);

	}

}



/*

 * Initialize the nandsim structure.

 *
@@ -435,14 +477,8 @@ init_nandsim(struct mtd_info *mtd) 
	printk("sector address bytes: %u\n",    ns->geom.secaddrbytes);

	printk("options: %#x\n",                ns->options);



	/* Map / allocate and initialize the flash image */

	ns->mem.byte = vmalloc(ns->geom.totszoob);

	if (!ns->mem.byte) {

		NS_ERR("init_nandsim: unable to allocate %u bytes for flash image\n",

			ns->geom.totszoob);

		return -ENOMEM;

	}

	memset(ns->mem.byte, 0xFF, ns->geom.totszoob);

	if (alloc_device(ns) != 0)

		goto error;



	/* Allocate / initialize the internal buffer */

	ns->buf.byte = kmalloc(ns->geom.pgszoob, GFP_KERNEL);
@@ -461,7 +497,7 @@ init_nandsim(struct mtd_info *mtd) 
	return 0;



error:

	vfree(ns->mem.byte);

	free_device(ns);



	return -ENOMEM;

}
@@ -473,7 +509,7 @@ static void 
free_nandsim(struct nandsim *ns)

{

	kfree(ns->buf.byte);

	vfree(ns->mem.byte);

	free_device(ns);



	return;

}
@@ -768,6 +804,84 @@ find_operation(struct nandsim *ns, uint32_t flag) 
	return -1;

}



/*

 * Returns a pointer to the current page.

 */

static inline union ns_mem *NS_GET_PAGE(struct nandsim *ns)

{

	return &(ns->pages[ns->regs.row]);

}



/*

 * Retuns a pointer to the current byte, within the current page.

 */

static inline u_char *NS_PAGE_BYTE_OFF(struct nandsim *ns)

{

	return NS_GET_PAGE(ns)->byte + ns->regs.column + ns->regs.off;

}



/*

 * Fill the NAND buffer with data read from the specified page.

 */

static void read_page(struct nandsim *ns, int num)

{

	union ns_mem *mypage;



	mypage = NS_GET_PAGE(ns);

	if (mypage->byte == NULL) {

		NS_DBG("read_page: page %d not allocated\n", ns->regs.row);

		memset(ns->buf.byte, 0xFF, num);

	} else {

		NS_DBG("read_page: page %d allocated, reading from %d\n",

			ns->regs.row, ns->regs.column + ns->regs.off);

		memcpy(ns->buf.byte, NS_PAGE_BYTE_OFF(ns), num);

	}

}



/*

 * Erase all pages in the specified sector.

 */

static void erase_sector(struct nandsim *ns)

{

	union ns_mem *mypage;

	int i;



	mypage = NS_GET_PAGE(ns);

	for (i = 0; i < ns->geom.pgsec; i++) {

		if (mypage->byte != NULL) {

			NS_DBG("erase_sector: freeing page %d\n", ns->regs.row+i);

			kfree(mypage->byte);

			mypage->byte = NULL;

		}

		mypage++;

	}

}



/*

 * Program the specified page with the contents from the NAND buffer.

 */

static int prog_page(struct nandsim *ns, int num)

{

	union ns_mem *mypage;

	u_char *pg_off;



	mypage = NS_GET_PAGE(ns);

	if (mypage->byte == NULL) {

		NS_DBG("prog_page: allocating page %d\n", ns->regs.row);

		mypage->byte = kmalloc(ns->geom.pgszoob, GFP_KERNEL);

		if (mypage->byte == NULL) {

			NS_ERR("prog_page: error allocating memory for page %d\n", ns->regs.row);

			return -1;

		}

		memset(mypage->byte, 0xFF, ns->geom.pgszoob);

	}



	pg_off = NS_PAGE_BYTE_OFF(ns);

	memcpy(pg_off, ns->buf.byte, num);



	return 0;

}



/*

 * If state has any action bit, perform this action.

 *
@@ -776,7 +890,7 @@ find_operation(struct nandsim *ns, uint32_t flag) 
static int

do_state_action(struct nandsim *ns, uint32_t action)

{

	int i, num;

	int num;

	int busdiv = ns->busw == 8 ? 1 : 2;



	action &= ACTION_MASK;
@@ -800,7 +914,7 @@ do_state_action(struct nandsim *ns, uint32_t action) 
			break;

		}

		num = ns->geom.pgszoob - ns->regs.off - ns->regs.column;

		memcpy(ns->buf.byte, ns->mem.byte + NS_RAW_OFFSET(ns) + ns->regs.off, num);

		read_page(ns, num);



		NS_DBG("do_state_action: (ACTION_CPY:) copy %d bytes to int buf, raw offset %d\n",

			num, NS_RAW_OFFSET(ns) + ns->regs.off);
@@ -841,7 +955,7 @@ do_state_action(struct nandsim *ns, uint32_t action) 
				ns->regs.row, NS_RAW_OFFSET(ns));

		NS_LOG("erase sector %d\n", ns->regs.row >> (ns->geom.secshift - ns->geom.pgshift));



		memset(ns->mem.byte + NS_RAW_OFFSET(ns), 0xFF, ns->geom.secszoob);

		erase_sector(ns);



		NS_MDELAY(erase_delay);
@@ -864,8 +978,8 @@ do_state_action(struct nandsim *ns, uint32_t action) 
			return -1;

		}



		for (i = 0; i < num; i++)

			ns->mem.byte[NS_RAW_OFFSET(ns) + ns->regs.off + i] &= ns->buf.byte[i];

		if (prog_page(ns, num) == -1)

			return -1;



		NS_DBG("do_state_action: copy %d bytes from int buf to (%#x, %#x), raw off = %d\n",

			num, ns->regs.row, ns->regs.column, NS_RAW_OFFSET(ns) + ns->regs.off);