part/dev_desc: Add log2 of blocksize to block_dev_desc data struct

log2 of the device block size serves as the shift value used to calculate
the block number to read in file systems when implementing avaiable block
sizes.
It is needed quite often in file systems thus it is pre-calculated and
stored in the block device descriptor.

Signed-off-by: Egbert Eich <eich@suse.com>

common/cmd_ide.c

@@ -455,6 +455,8 @@ void ide_init(void)
 		ide_dev_desc[i].dev = i;
 		ide_dev_desc[i].part_type = PART_TYPE_UNKNOWN;
 		ide_dev_desc[i].blksz = 0;
+		ide_dev_desc[i].log2blksz =
+			LOG2_INVALID(typeof(ide_dev_desc[i].log2blksz));
 		ide_dev_desc[i].lba = 0;
 		ide_dev_desc[i].block_read = ide_read;
 		ide_dev_desc[i].block_write = ide_write;
@@ -806,6 +808,7 @@ static void ide_ident(block_dev_desc_t *dev_desc)
 	/* assuming HD */
 	dev_desc->type = DEV_TYPE_HARDDISK;
 	dev_desc->blksz = ATA_BLOCKSIZE;
+	dev_desc->log2blksz = LOG2(dev_desc->blksz);
 	dev_desc->lun = 0;	/* just to fill something in... */
 
 #if 0				/* only used to test the powersaving mode,
@@ -1448,6 +1451,7 @@ static void atapi_inquiry(block_dev_desc_t *dev_desc)
 	dev_desc->lun = 0;
 	dev_desc->lba = 0;
 	dev_desc->blksz = 0;
+	dev_desc->log2blksz = LOG2_INVALID(typeof(dev_desc->log2blksz));
 	dev_desc->type = iobuf[0] & 0x1f;
 
 	if ((iobuf[1] & 0x80) == 0x80)
@@ -1492,6 +1496,7 @@ static void atapi_inquiry(block_dev_desc_t *dev_desc)
 	dev_desc->blksz = ((unsigned long) iobuf[4] << 24) +
 		((unsigned long) iobuf[5] << 16) +
 		((unsigned long) iobuf[6] << 8) + ((unsigned long) iobuf[7]);
+	dev_desc->log2blksz = LOG2(dev_desc->blksz);
 #ifdef CONFIG_LBA48
 	/* ATAPI devices cannot use 48bit addressing (ATA/ATAPI v7) */
 	dev_desc->lba48 = 0;

common/cmd_sata.c

@@ -44,6 +44,7 @@ int __sata_initialize(void)
 		sata_dev_desc[i].type = DEV_TYPE_HARDDISK;
 		sata_dev_desc[i].lba = 0;
 		sata_dev_desc[i].blksz = 512;
+		sata_dev_desc[i].log2blksz = LOG2(sata_dev_desc[i].blksz);
 		sata_dev_desc[i].block_read = sata_read;
 		sata_dev_desc[i].block_write = sata_write;
 

common/cmd_scsi.c

@@ -106,6 +106,8 @@ void scsi_scan(int mode)
 		scsi_dev_desc[i].lun=0xff;
 		scsi_dev_desc[i].lba=0;
 		scsi_dev_desc[i].blksz=0;
+		scsi_dev_desc[i].log2blksz =
+			LOG2_INVALID(typeof(scsi_dev_desc[i].log2blksz));
 		scsi_dev_desc[i].type=DEV_TYPE_UNKNOWN;
 		scsi_dev_desc[i].vendor[0]=0;
 		scsi_dev_desc[i].product[0]=0;
@@ -166,6 +168,8 @@ void scsi_scan(int mode)
 			}
 			scsi_dev_desc[scsi_max_devs].lba=capacity;
 			scsi_dev_desc[scsi_max_devs].blksz=blksz;
+			scsi_dev_desc[scsi_max_devs].log2blksz =
+				LOG2(scsi_dev_desc[scsi_max_devs].blksz);
 			scsi_dev_desc[scsi_max_devs].type=perq;
 			init_part(&scsi_dev_desc[scsi_max_devs]);
 removable:

common/usb_storage.c

@@ -1430,6 +1430,7 @@ int usb_stor_get_info(struct usb_device *dev, struct us_data *ss,
 			*capacity, *blksz);
 	dev_desc->lba = *capacity;
 	dev_desc->blksz = *blksz;
+	dev_desc->log2blksz = LOG2(dev_desc->blksz);
 	dev_desc->type = perq;
 	USB_STOR_PRINTF(" address %d\n", dev_desc->target);
 	USB_STOR_PRINTF("partype: %d\n", dev_desc->part_type);

drivers/block/ata_piix.c

@@ -406,6 +406,7 @@ void sata_identify(int num, int dev)
 	/* assuming HD */
 	sata_dev_desc[devno].type = DEV_TYPE_HARDDISK;
 	sata_dev_desc[devno].blksz = ATA_BLOCKSIZE;
+	sata_dev_desc[devno].log2blksz = LOG2(sata_dev_desc[devno].blksz);
 	sata_dev_desc[devno].lun = 0;	/* just to fill something in... */
 }
 

drivers/block/pata_bfin.c

@@ -897,6 +897,8 @@ static void bfin_ata_identify(struct ata_port *ap, int dev)
 	/* assuming HD */
 	sata_dev_desc[ap->port_no].type = DEV_TYPE_HARDDISK;
 	sata_dev_desc[ap->port_no].blksz = ATA_SECT_SIZE;
+	sata_dev_desc[ap->port_no].log2blksz =
+		LOG2(sata_dev_desc[ap->port_no].blksz);
 	sata_dev_desc[ap->port_no].lun = 0;	/* just to fill something in... */
 
 	printf("PATA device#%d %s is found on ata port#%d.\n",

drivers/block/systemace.c

@@ -127,6 +127,7 @@ block_dev_desc_t *systemace_get_dev(int dev)
 		systemace_dev.part_type = PART_TYPE_UNKNOWN;
 		systemace_dev.type = DEV_TYPE_HARDDISK;
 		systemace_dev.blksz = 512;
+		systemace_dev.log2blksz = LOG2(systemace_dev.blksz);
 		systemace_dev.removable = 1;
 		systemace_dev.block_read = systemace_read;
 

drivers/mmc/mmc.c

@@ -1203,6 +1203,7 @@ static int mmc_startup(struct mmc *mmc)
 	mmc->block_dev.lun = 0;
 	mmc->block_dev.type = 0;
 	mmc->block_dev.blksz = mmc->read_bl_len;
+	mmc->block_dev.log2blksz = LOG2(mmc->block_dev.blksz);
 	mmc->block_dev.lba = lldiv(mmc->capacity, mmc->read_bl_len);
 	sprintf(mmc->block_dev.vendor, "Man %06x Snr %04x%04x",
 		mmc->cid[0] >> 24, (mmc->cid[2] & 0xffff),

include/part.h

@@ -38,6 +38,7 @@ typedef struct block_dev_desc {
 #endif
 	lbaint_t	lba;		/* number of blocks */
 	unsigned long	blksz;		/* block size */
+	int		log2blksz;	/* for convenience: log2(blksz) */
 	char		vendor [40+1];	/* IDE model, SCSI Vendor */
 	char		product[20+1];	/* IDE Serial no, SCSI product */
 	char		revision[8+1];	/* firmware revision */
@@ -58,6 +59,10 @@ typedef struct block_dev_desc {
 #define BLOCK_CNT(size, block_dev_desc) (PAD_COUNT(size, block_dev_desc->blksz))
 #define PAD_TO_BLOCKSIZE(size, block_dev_desc) \
 	(PAD_SIZE(size, block_dev_desc->blksz))
+#define LOG2(x) (((x & 0xaaaaaaaa) ? 1 : 0) + ((x & 0xcccccccc) ? 2 : 0) + \
+		 ((x & 0xf0f0f0f0) ? 4 : 0) + ((x & 0xff00ff00) ? 8 : 0) + \
+		 ((x & 0xffff0000) ? 16 : 0))
+#define LOG2_INVALID(type) ((type)((sizeof(type)<<3)-1))
 
 /* Interface types: */
 #define IF_TYPE_UNKNOWN		0