MTD: Make phram work again

o Add simple usage example.
o Fix up unit handling (k, M. G).
o Use correct size limit for setup string.
o Remove pointless printk message.
o Fix mtdblock to not allocate a read-modify-write buffer for CAP_RAM
  devices (and fail to do so, returning an error).
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

drivers/mtd/devices/phram.c

 /**
  *
- * $Id: phram.c,v 1.3 2004/11/16 18:29:01 dwmw2 Exp $
+ * $Id: phram.c,v 1.6 2004/11/25 16:51:09 joern Exp $
  *
  * Copyright (c) Jochen Schaeuble <psionic@psionic.de>
  * 07/2003	rewritten by Joern Engel <joern@wh.fh-wedel.de>
@@ -15,9 +15,12 @@
  *   phram=<name>,<start>,<len>
  * <name> may be up to 63 characters.
  * <start> and <len> can be octal, decimal or hexadecimal.  If followed
- * by "k", "M" or "G", the numbers will be interpreted as kilo, mega or
+ * by "ki", "Mi" or "Gi", the numbers will be interpreted as kilo, mega or
  * gigabytes.
  *
+ * Example:
+ *	phram=swap,896Mi,110Mi phram=test,1006Mi,1Mi
+ *
  */
 
 #include <asm/io.h>
@@ -184,7 +187,9 @@ static int ustrtoul(const char *cp, char **endp, unsigned int base)
 		result *= 1024;
 	case 'k':
 		result *= 1024;
-		endp++;
+	/* By dwmw2 editorial decree, "ki", "Mi" or "Gi" are to be used. */
+		if ((*endp)[1] == 'i')
+			(*endp) += 2;
 	}
 	return result;
 }
@@ -235,7 +240,7 @@ static int phram_setup(const char *val, struct kernel_param *kp)
 	uint32_t len;
 	int i, ret;
 
-	if (strnlen(val, sizeof(str)) >= sizeof(str))
+	if (strnlen(val, sizeof(buf)) >= sizeof(buf))
 		parse_err("parameter too long\n");
 
 	strcpy(str, val);
@@ -283,7 +288,7 @@ static int __init slram_setup(const char *val, struct kernel_param *kp)
 	if (!val || !val[0])
 		parse_err("no arguments to \"slram=\"\n");
 
-	if (strnlen(val, sizeof(str)) >= sizeof(str))
+	if (strnlen(val, sizeof(buf)) >= sizeof(buf))
 		parse_err("parameter too long\n");
 
 	strcpy(str, val);
@@ -342,7 +347,6 @@ MODULE_PARM_DESC(slram, "List of memory regions to map. \"map=<name>,<start><len
 
 static int __init init_phram(void)
 {
-	printk(KERN_ERR "phram loaded\n");
 	return 0;
 }
 

drivers/mtd/mtdblock.c

 /* 
  * Direct MTD block device access
  *
- * $Id: mtdblock.c,v 1.65 2004/11/16 18:28:59 dwmw2 Exp $
+ * $Id: mtdblock.c,v 1.66 2004/11/25 13:52:52 joern Exp $
  *
  * (C) 2000-2003 Nicolas Pitre <nico@cam.org>
  * (C) 1999-2003 David Woodhouse <dwmw2@infradead.org>
@@ -248,7 +248,7 @@ static int mtdblock_writesect(struct mtd_blktrans_dev *dev,
 			      unsigned long block, char *buf)
 {
 	struct mtdblk_dev *mtdblk = mtdblks[dev->devnum];
-	if (unlikely(!mtdblk->cache_data)) {
+	if (unlikely(!mtdblk->cache_data && mtdblk->cache_size)) {
 		mtdblk->cache_data = vmalloc(mtdblk->mtd->erasesize);
 		if (!mtdblk->cache_data)
 			return -EINTR;