ahci: Make the AHCI code find the capacity of disks > 128 GB properly

In the structure returned by the ATA identify device command, there are two
fields which describe the device capacity. One is a 32 bit data type which
reports the number of sectors as a 28 bit LBA, and the other is a 64 bit data
type which is for a 48 bit LBA. If the device doesn't support 48 bit LBAs,
the small value is the only value with the correct size. If it supports more,
if the number of sectors is small enough to fit into 28 bits, both fields
reflect the correct value. If it's too large, the smaller field has 28 bits of
1s, 0xfffffff, and the other field has the correct value.

The AHCI driver is implemented by attaching to the generic SCSI code and
translating on the fly between SCSI binary data structures and AHCI data
structures. It responds to requests to execute specific SCSI commands by
executing the equivalent AHCI commands and then crafting a response which
matches what a SCSI disk would send.

The AHCI driver now considers both fields and chooses the correct one when
implementing both the SCSI READ CAPACITY (10) and READ CAPACITY (16) commands.

Signed-off-by: Gabe Black <gabeblack@chromium.org>
Signed-off-by: Simon Glass <sjg@chromium.org>

drivers/block/ahci.c

@@ -672,6 +672,7 @@ static int ata_scsiop_read_write(ccb *pccb, u8 is_write)
 static int ata_scsiop_read_capacity10(ccb *pccb)
 {
 	u32 cap;
+	u32 block_size;
 
 	if (!ataid[pccb->target]) {
 		printf("scsi_ahci: SCSI READ CAPACITY10 command failure. "
@@ -680,12 +681,53 @@ static int ata_scsiop_read_capacity10(ccb *pccb)
 		return -EPERM;
 	}
 
-	cap = be32_to_cpu(ataid[pccb->target]->lba_capacity);
+	cap = le32_to_cpu(ataid[pccb->target]->lba_capacity);
+	if (cap == 0xfffffff) {
+		unsigned short *cap48 = ataid[pccb->target]->lba48_capacity;
+		if (cap48[2] || cap48[3]) {
+			cap = 0xffffffff;
+		} else {
+			cap = (le16_to_cpu(cap48[1]) << 16) |
+			      (le16_to_cpu(cap48[0]));
+		}
+	}
+
+	cap = cpu_to_be32(cap);
 	memcpy(pccb->pdata, &cap, sizeof(cap));
 
-	pccb->pdata[4] = pccb->pdata[5] = 0;
-	pccb->pdata[6] = 512 >> 8;
-	pccb->pdata[7] = 512 & 0xff;
+	block_size = cpu_to_be32((u32)512);
+	memcpy(&pccb->pdata[4], &block_size, 4);
+
+	return 0;
+}
+
+
+/*
+ * SCSI READ CAPACITY16 command operation.
+ */
+static int ata_scsiop_read_capacity16(ccb *pccb)
+{
+	u64 cap;
+	u64 block_size;
+
+	if (!ataid[pccb->target]) {
+		printf("scsi_ahci: SCSI READ CAPACITY16 command failure. "
+		       "\tNo ATA info!\n"
+		       "\tPlease run SCSI commmand INQUIRY firstly!\n");
+		return -EPERM;
+	}
+
+	cap = le32_to_cpu(ataid[pccb->target]->lba_capacity);
+	if (cap == 0xfffffff) {
+		memcpy(&cap, ataid[pccb->target]->lba48_capacity, sizeof(cap));
+		cap = le64_to_cpu(cap);
+	}
+
+	cap = cpu_to_be64(cap);
+	memcpy(pccb->pdata, &cap, sizeof(cap));
+
+	block_size = cpu_to_be64((u64)512);
+	memcpy(&pccb->pdata[8], &block_size, 8);
 
 	return 0;
 }
@@ -711,9 +753,12 @@ int scsi_exec(ccb *pccb)
 	case SCSI_WRITE10:
 		ret = ata_scsiop_read_write(pccb, 1);
 		break;
-	case SCSI_RD_CAPAC:
+	case SCSI_RD_CAPAC10:
 		ret = ata_scsiop_read_capacity10(pccb);
 		break;
+	case SCSI_RD_CAPAC16:
+		ret = ata_scsiop_read_capacity16(pccb);
+		break;
 	case SCSI_TST_U_RDY:
 		ret = ata_scsiop_test_unit_ready(pccb);
 		break;

include/scsi.h

@@ -150,6 +150,8 @@ typedef struct SCSI_cmd_block{
 #define SCSI_READ6		0x08		/* Read 6-byte (MANDATORY) */
 #define SCSI_READ10		0x28		/* Read 10-byte (MANDATORY) */
 #define SCSI_RD_CAPAC	0x25		/* Read Capacity (MANDATORY) */
+#define SCSI_RD_CAPAC10	SCSI_RD_CAPAC	/* Read Capacity (10) */
+#define SCSI_RD_CAPAC16	0x9e		/* Read Capacity (16) */
 #define SCSI_RD_DEFECT	0x37		/* Read Defect Data (O) */
 #define SCSI_READ_LONG	0x3E		/* Read Long (O) */
 #define SCSI_REASS_BLK	0x07		/* Reassign Blocks (O) */