From d086d43640a40dda7783f3c56724048685586d17 Mon Sep 17 00:00:00 2001 From: Vijay Kumar Date: Sun, 8 Oct 2006 22:02:31 +0530 Subject: [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: Vijay Kumar Signed-off-by: David Woodhouse --- drivers/mtd/nand/nandsim.c | 162 ++++++++++++++++++++++++++++++++++++++------- 1 file changed, 138 insertions(+), 24 deletions(-) (limited to 'drivers/mtd') diff --git a/drivers/mtd/nand/nandsim.c b/drivers/mtd/nand/nandsim.c index 5dd3c4eb4f0..f00e195f471 100644 --- a/drivers/mtd/nand/nandsim.c +++ b/drivers/mtd/nand/nandsim.c @@ -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); 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