[MTD] update internal API to support 64-bit device size

MTD internal API presently uses 32-bit values to represent
device size.  This patch updates them to 64-bits but leaves
the external API unchanged.  Extending the external API
is a separate issue for several reasons.  First, no one
needs it at the moment.  Secondly, whether the implementation
is done with IOCTLs, sysfs or both is still debated.  Thirdly
external API changes require the internal API to be accepted
first.

Note that although the MTD API will be able to support 64-bit
device sizes, existing drivers do not and are not required
to do so, although NAND base has been updated.

In general, changing from 32-bit to 64-bit values cause little
or no changes to the majority of the code with the following
exceptions:
    	- printk message formats
    	- division and modulus of 64-bit values
    	- NAND base support
	- 32-bit local variables used by mtdpart and mtdconcat
	- naughtily assuming one structure maps to another
	in MEMERASE ioctl

Signed-off-by: Adrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 49 insertions, 8 deletions

diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h
index eae26bb6430a..95e585ecc297 100644
--- a/include/linux/mtd/mtd.h
+++ b/include/linux/mtd/mtd.h
@@ -15,6 +15,8 @@
 #include <linux/mtd/compatmac.h>
 #include <mtd/mtd-abi.h>
 
+#include <asm/div64.h>
+
 #define MTD_CHAR_MAJOR 90
 #define MTD_BLOCK_MAJOR 31
 #define MAX_MTD_DEVICES 32
@@ -25,16 +27,16 @@
 #define MTD_ERASE_DONE          0x08
 #define MTD_ERASE_FAILED        0x10
 
-#define MTD_FAIL_ADDR_UNKNOWN 0xffffffff
+#define MTD_FAIL_ADDR_UNKNOWN -1LL
 
 /* If the erase fails, fail_addr might indicate exactly which block failed.  If
    fail_addr = MTD_FAIL_ADDR_UNKNOWN, the failure was not at the device level or was not
    specific to any particular block. */
 struct erase_info {
 	struct mtd_info *mtd;
-	u_int32_t addr;
-	u_int32_t len;
-	u_int32_t fail_addr;
+	uint64_t addr;
+	uint64_t len;
+	uint64_t fail_addr;
 	u_long time;
 	u_long retries;
 	u_int dev;
@@ -46,7 +48,7 @@ struct erase_info {
 };
 
 struct mtd_erase_region_info {
-	u_int32_t offset;			/* At which this region starts, from the beginning of the MTD */
+	uint64_t offset;			/* At which this region starts, from the beginning of the MTD */
 	u_int32_t erasesize;		/* For this region */
 	u_int32_t numblocks;		/* Number of blocks of erasesize in this region */
 	unsigned long *lockmap;		/* If keeping bitmap of locks */
@@ -101,7 +103,7 @@ struct mtd_oob_ops {
 struct mtd_info {
 	u_char type;
 	u_int32_t flags;
-	u_int32_t size;	 // Total size of the MTD
+	uint64_t size;	 // Total size of the MTD
 
 	/* "Major" erase size for the device. Naïve users may take this
 	 * to be the only erase size available, or may use the more detailed
@@ -120,6 +122,16 @@ struct mtd_info {
 	u_int32_t oobsize;   // Amount of OOB data per block (e.g. 16)
 	u_int32_t oobavail;  // Available OOB bytes per block
 
+	/*
+	 * If erasesize is a power of 2 then the shift is stored in
+	 * erasesize_shift otherwise erasesize_shift is zero. Ditto writesize.
+	 */
+	unsigned int erasesize_shift;
+	unsigned int writesize_shift;
+	/* Masks based on erasesize_shift and writesize_shift */
+	unsigned int erasesize_mask;
+	unsigned int writesize_mask;
+
 	// Kernel-only stuff starts here.
 	const char *name;
 	int index;
@@ -190,8 +202,8 @@ struct mtd_info {
 	void (*sync) (struct mtd_info *mtd);
 
 	/* Chip-supported device locking */
-	int (*lock) (struct mtd_info *mtd, loff_t ofs, size_t len);
-	int (*unlock) (struct mtd_info *mtd, loff_t ofs, size_t len);
+	int (*lock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
+	int (*unlock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
 
 	/* Power Management functions */
 	int (*suspend) (struct mtd_info *mtd);
@@ -221,6 +233,35 @@ struct mtd_info {
 	void (*put_device) (struct mtd_info *mtd);
 };
 
+static inline u_int32_t mtd_div_by_eb(uint64_t sz, struct mtd_info *mtd)
+{
+	if (mtd->erasesize_shift)
+		return sz >> mtd->erasesize_shift;
+	do_div(sz, mtd->erasesize);
+	return sz;
+}
+
+static inline u_int32_t mtd_mod_by_eb(uint64_t sz, struct mtd_info *mtd)
+{
+	if (mtd->erasesize_shift)
+		return sz & mtd->erasesize_mask;
+	return do_div(sz, mtd->erasesize);
+}
+
+static inline u_int32_t mtd_div_by_ws(uint64_t sz, struct mtd_info *mtd)
+{
+	if (mtd->writesize_shift)
+		return sz >> mtd->writesize_shift;
+	do_div(sz, mtd->writesize);
+	return sz;
+}
+
+static inline u_int32_t mtd_mod_by_ws(uint64_t sz, struct mtd_info *mtd)
+{
+	if (mtd->writesize_shift)
+		return sz & mtd->writesize_mask;
+	return do_div(sz, mtd->writesize);
+}
 
 	/* Kernel-side ioctl definitions */