[MTD] NAND: nandsim page-wise allocation (2/2)
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linux-mtd at lists.infradead.org
Sat Oct 21 11:59:04 EDT 2006
Commit: d086d43640a40dda7783f3c56724048685586d17
Parent: 47e37743381823a5c2d51ef88cfc3d6cff1f8580
commit d086d43640a40dda7783f3c56724048685586d17
Author: Vijay Kumar <vijaykumar at bravegnu.org>
AuthorDate: Sun Oct 8 22:02:31 2006 +0530
Commit: David Woodhouse <dwmw2 at infradead.org>
CommitDate: Sat Oct 21 16:40:27 2006 +0100
[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 <vijaykumar at bravegnu.org>
Signed-off-by: David Woodhouse <dwmw2 at infradead.org>
---
drivers/mtd/nand/nandsim.c | 162 +++++++++++++++++++++++++++++++++++++-------
1 files changed, 138 insertions(+), 24 deletions(-)
diff --git a/drivers/mtd/nand/nandsim.c b/drivers/mtd/nand/nandsim.c
index 5dd3c4e..f00e195 100644
--- a/drivers/mtd/nand/nandsim.c
+++ b/drivers/mtd/nand/nandsim.c
@@ -227,6 +227,14 @@ #define NS_STATE(x) ((x) & ~ACTION_MASK)
#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.
*/
struct nandsim {
@@ -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 {
@@ -342,6 +344,46 @@ 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.
*
* RETURNS: 0 if success, -ERRNO if failure.
@@ -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;
}
@@ -769,6 +805,84 @@ find_operation(struct nandsim *ns, uint3
}
/*
+ * 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.
*
* RETURNS: 0 if success, -1 if error.
@@ -776,7 +890,7 @@ find_operation(struct nandsim *ns, uint3
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, uint
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, uint
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, uint
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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