mpt2sas: Avoid type casting for direct I/O commands

A type casting error caused the max volume LBA to be truncated from 64
to 32 bits. The virtual LBA would also get truncated to 32 bits in the
case of a 16-byte READ/WRITE command.

Rewrite entire function to get rid of code duplication and type casts.
Use get/put_unaligned wrappers to extract and replace the LBA field in
the MPI request CDB.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Tested-by: Sreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

1 files changed, 40 insertions, 77 deletions

diff --git a/drivers/scsi/mpt2sas/mpt2sas_scsih.c b/drivers/scsi/mpt2sas/mpt2sas_scsih.c
index e7303edc3d8e..231ec34d8ea9 100644
--- a/drivers/scsi/mpt2sas/mpt2sas_scsih.c
+++ b/drivers/scsi/mpt2sas/mpt2sas_scsih.c
@@ -55,6 +55,8 @@
 #include <linux/raid_class.h>
 #include <linux/slab.h>
 
+#include <asm/unaligned.h>
+
 #include "mpt2sas_base.h"
 
 MODULE_AUTHOR(MPT2SAS_AUTHOR);
@@ -3858,85 +3860,46 @@ _scsih_setup_direct_io(struct MPT2SAS_ADAPTER *ioc, struct scsi_cmnd *scmd,
         struct _raid_device *raid_device, Mpi2SCSIIORequest_t *mpi_request,
         u16 smid)
 {
-        u32 v_lba, p_lba, stripe_off, stripe_unit, column, io_size;
+        sector_t v_lba, p_lba, stripe_off, stripe_unit, column, io_size;
         u32 stripe_sz, stripe_exp;
-        u8 num_pds, *cdb_ptr, i;
-        u8 cdb0 = scmd->cmnd[0];
-        u64 v_llba;
+        u8 num_pds, cmd = scmd->cmnd[0];
 
-        /*
-         * Try Direct I/O to RAID memeber disks
-         */
-        if (cdb0 == READ_16 || cdb0 == READ_10 ||
-            cdb0 == WRITE_16 || cdb0 == WRITE_10) {
-                cdb_ptr = mpi_request->CDB.CDB32;
-
-                if ((cdb0 < READ_16) || !(cdb_ptr[2] | cdb_ptr[3] | cdb_ptr[4]
-                        | cdb_ptr[5])) {
-                        io_size = scsi_bufflen(scmd) >>
-                            raid_device->block_exponent;
-                        i = (cdb0 < READ_16) ? 2 : 6;
-                        /* get virtual lba */
-                        v_lba = be32_to_cpu(*(__be32 *)(&cdb_ptr[i]));
-
-                        if (((u64)v_lba + (u64)io_size - 1) <=
-                            (u32)raid_device->max_lba) {
-                                stripe_sz = raid_device->stripe_sz;
-                                stripe_exp = raid_device->stripe_exponent;
-                                stripe_off = v_lba & (stripe_sz - 1);
-
-                                /* Check whether IO falls within a stripe */
-                                if ((stripe_off + io_size) <= stripe_sz) {
-                                        num_pds = raid_device->num_pds;
-                                        p_lba = v_lba >> stripe_exp;
-                                        stripe_unit = p_lba / num_pds;
-                                        column = p_lba % num_pds;
-                                        p_lba = (stripe_unit << stripe_exp) +
-                                            stripe_off;
-                                        mpi_request->DevHandle =
-                                                cpu_to_le16(raid_device->
-                                                    pd_handle[column]);
-                                        (*(__be32 *)(&cdb_ptr[i])) =
-                                                cpu_to_be32(p_lba);
-                                        /*
-                                        * WD: To indicate this I/O is directI/O
-                                        */
-                                        _scsih_scsi_direct_io_set(ioc, smid, 1);
-                                }
-                        }
-                } else {
-                        io_size = scsi_bufflen(scmd) >>
-                            raid_device->block_exponent;
-                        /* get virtual lba */
-                        v_llba = be64_to_cpu(*(__be64 *)(&cdb_ptr[2]));
-
-                        if ((v_llba + (u64)io_size - 1) <=
-                            raid_device->max_lba) {
-                                stripe_sz = raid_device->stripe_sz;
-                                stripe_exp = raid_device->stripe_exponent;
-                                stripe_off = (u32) (v_llba & (stripe_sz - 1));
-
-                                /* Check whether IO falls within a stripe */
-                                if ((stripe_off + io_size) <= stripe_sz) {
-                                        num_pds = raid_device->num_pds;
-                                        p_lba = (u32)(v_llba >> stripe_exp);
-                                        stripe_unit = p_lba / num_pds;
-                                        column = p_lba % num_pds;
-                                        p_lba = (stripe_unit << stripe_exp) +
-                                            stripe_off;
-                                        mpi_request->DevHandle =
-                                                cpu_to_le16(raid_device->
-                                                    pd_handle[column]);
-                                        (*(__be64 *)(&cdb_ptr[2])) =
-                                            cpu_to_be64((u64)p_lba);
-                                        /*
-                                        * WD: To indicate this I/O is directI/O
-                                        */
-                                        _scsih_scsi_direct_io_set(ioc, smid, 1);
-                                }
-                        }
-                }
-        }
+        if (cmd != READ_10 && cmd != WRITE_10 &&
+            cmd != READ_16 && cmd != WRITE_16)
+                return;
+
+        if (cmd == READ_10 || cmd == WRITE_10)
+                v_lba = get_unaligned_be32(&mpi_request->CDB.CDB32[2]);
+        else
+                v_lba = get_unaligned_be64(&mpi_request->CDB.CDB32[2]);
+
+        io_size = scsi_bufflen(scmd) >> raid_device->block_exponent;
+
+        if (v_lba + io_size - 1 > raid_device->max_lba)
+                return;
+
+        stripe_sz = raid_device->stripe_sz;
+        stripe_exp = raid_device->stripe_exponent;
+        stripe_off = v_lba & (stripe_sz - 1);
+
+        /* Return unless IO falls within a stripe */
+        if (stripe_off + io_size > stripe_sz)
+                return;
+
+        num_pds = raid_device->num_pds;
+        p_lba = v_lba >> stripe_exp;
+        stripe_unit = p_lba / num_pds;
+        column = p_lba % num_pds;
+        p_lba = (stripe_unit << stripe_exp) + stripe_off;
+        mpi_request->DevHandle = cpu_to_le16(raid_device->pd_handle[column]);
+
+        if (cmd == READ_10 || cmd == WRITE_10)
+                put_unaligned_be32(lower_32_bits(p_lba),
+                                   &mpi_request->CDB.CDB32[2]);
+        else
+                put_unaligned_be64(p_lba, &mpi_request->CDB.CDB32[2]);
+
+        _scsih_scsi_direct_io_set(ioc, smid, 1);
 }
 
 /**