[SCSI] zfcp: Introduce experimental support for DIF/DIX

Introduce support for DIF/DIX in zfcp: Report the capabilities for the
Scsi_host, map the protection data when issuing I/O requests and
handle the new error codes. Also add the fsf data_direction field to
the hba trace, it is useful information for debugging in that area.
This is an EXPERIMENTAL feature for now.

Signed-off-by: Felix Beck <felix.beck@de.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

9 files changed, 185 insertions, 30 deletions

diff --git a/drivers/s390/scsi/zfcp_dbf.c b/drivers/s390/scsi/zfcp_dbf.c
index a08d33a96ec9..a86117b0d6e1 100644
--- a/drivers/s390/scsi/zfcp_dbf.c
+++ b/drivers/s390/scsi/zfcp_dbf.c
@@ -155,6 +155,8 @@ void _zfcp_dbf_hba_fsf_response(const char *tag2, int level,
                 if (scsi_cmnd) {
                         response->u.fcp.cmnd = (unsigned long)scsi_cmnd;
                         response->u.fcp.serial = scsi_cmnd->serial_number;
+                        response->u.fcp.data_dir =
+                                qtcb->bottom.io.data_direction;
                 }
                 break;
 
@@ -326,6 +328,7 @@ static void zfcp_dbf_hba_view_response(char **p,
         case FSF_QTCB_FCP_CMND:
                 if (r->fsf_req_status & ZFCP_STATUS_FSFREQ_TASK_MANAGEMENT)
                         break;
+                zfcp_dbf_out(p, "data_direction", "0x%04x", r->u.fcp.data_dir);
                 zfcp_dbf_out(p, "scsi_cmnd", "0x%0Lx", r->u.fcp.cmnd);
                 zfcp_dbf_out(p, "scsi_serial", "0x%016Lx", r->u.fcp.serial);
                 *p += sprintf(*p, "\n");
diff --git a/drivers/s390/scsi/zfcp_dbf.h b/drivers/s390/scsi/zfcp_dbf.h
index 457e046f2d28..2bcc3403126a 100644
--- a/drivers/s390/scsi/zfcp_dbf.h
+++ b/drivers/s390/scsi/zfcp_dbf.h
@@ -111,6 +111,7 @@ struct zfcp_dbf_hba_record_response {
                 struct {
                         u64 cmnd;
                         u64 serial;
+                        u32 data_dir;
                 } fcp;
                 struct {
                         u64 wwpn;
diff --git a/drivers/s390/scsi/zfcp_ext.h b/drivers/s390/scsi/zfcp_ext.h
index a8bb7488dc98..de0925f25dcc 100644
--- a/drivers/s390/scsi/zfcp_ext.h
+++ b/drivers/s390/scsi/zfcp_ext.h
@@ -164,6 +164,8 @@ extern void zfcp_scsi_schedule_rport_block(struct zfcp_port *);
 extern void zfcp_scsi_schedule_rports_block(struct zfcp_adapter *);
 extern void zfcp_scsi_scan(struct zfcp_unit *);
 extern void zfcp_scsi_scan_work(struct work_struct *);
+extern void zfcp_scsi_set_prot(struct zfcp_adapter *);
+extern void zfcp_scsi_dif_sense_error(struct scsi_cmnd *, int);
 
 /* zfcp_sysfs.c */
 extern struct attribute_group zfcp_sysfs_unit_attrs;
diff --git a/drivers/s390/scsi/zfcp_fc.h b/drivers/s390/scsi/zfcp_fc.h
index 85c37d2b82c2..938d50360166 100644
--- a/drivers/s390/scsi/zfcp_fc.h
+++ b/drivers/s390/scsi/zfcp_fc.h
@@ -220,6 +220,9 @@ void zfcp_fc_scsi_to_fcp(struct fcp_cmnd *fcp, struct scsi_cmnd *scsi)
         memcpy(fcp->fc_cdb, scsi->cmnd, scsi->cmd_len);
 
         fcp->fc_dl = scsi_bufflen(scsi);
+
+        if (scsi_get_prot_type(scsi) == SCSI_PROT_DIF_TYPE1)
+                fcp->fc_dl += fcp->fc_dl / scsi->device->sector_size * 8;
 }
 
 /**
diff --git a/drivers/s390/scsi/zfcp_fsf.c b/drivers/s390/scsi/zfcp_fsf.c
index 63402fd5f9ae..f9be5d60d92a 100644
--- a/drivers/s390/scsi/zfcp_fsf.c
+++ b/drivers/s390/scsi/zfcp_fsf.c
@@ -526,6 +526,8 @@ static int zfcp_fsf_exchange_config_evaluate(struct zfcp_fsf_req *req)
                 return -EIO;
         }
 
+        zfcp_scsi_set_prot(adapter);
+
         return 0;
 }
 
@@ -988,6 +990,7 @@ static int zfcp_fsf_setup_ct_els_sbals(struct zfcp_fsf_req *req,
         bytes = zfcp_qdio_sbals_from_sg(adapter->qdio, &req->qdio_req, sg_req);
         if (bytes <= 0)
                 return -EIO;
+        zfcp_qdio_set_sbale_last(adapter->qdio, &req->qdio_req);
         req->qtcb->bottom.support.req_buf_length = bytes;
         zfcp_qdio_skip_to_last_sbale(&req->qdio_req);
 
@@ -996,6 +999,7 @@ static int zfcp_fsf_setup_ct_els_sbals(struct zfcp_fsf_req *req,
         req->qtcb->bottom.support.resp_buf_length = bytes;
         if (bytes <= 0)
                 return -EIO;
+        zfcp_qdio_set_sbale_last(adapter->qdio, &req->qdio_req);
 
         return 0;
 }
@@ -2038,9 +2042,13 @@ static void zfcp_fsf_req_trace(struct zfcp_fsf_req *req, struct scsi_cmnd *scsi)
                 blktrc.fabric_lat = lat_in->fabric_lat * ticks;
 
                 switch (req->qtcb->bottom.io.data_direction) {
+                case FSF_DATADIR_DIF_READ_STRIP:
+                case FSF_DATADIR_DIF_READ_CONVERT:
                 case FSF_DATADIR_READ:
                         lat = &unit->latencies.read;
                         break;
+                case FSF_DATADIR_DIF_WRITE_INSERT:
+                case FSF_DATADIR_DIF_WRITE_CONVERT:
                 case FSF_DATADIR_WRITE:
                         lat = &unit->latencies.write;
                         break;
@@ -2081,6 +2089,21 @@ static void zfcp_fsf_send_fcp_command_task_handler(struct zfcp_fsf_req *req)
                 goto skip_fsfstatus;
         }
 
+        switch (req->qtcb->header.fsf_status) {
+        case FSF_INCONSISTENT_PROT_DATA:
+        case FSF_INVALID_PROT_PARM:
+                set_host_byte(scpnt, DID_ERROR);
+                goto skip_fsfstatus;
+        case FSF_BLOCK_GUARD_CHECK_FAILURE:
+                zfcp_scsi_dif_sense_error(scpnt, 0x1);
+                goto skip_fsfstatus;
+        case FSF_APP_TAG_CHECK_FAILURE:
+                zfcp_scsi_dif_sense_error(scpnt, 0x2);
+                goto skip_fsfstatus;
+        case FSF_REF_TAG_CHECK_FAILURE:
+                zfcp_scsi_dif_sense_error(scpnt, 0x3);
+                goto skip_fsfstatus;
+        }
         fcp_rsp = (struct fcp_resp_with_ext *) &req->qtcb->bottom.io.fcp_rsp;
         zfcp_fc_eval_fcp_rsp(fcp_rsp, scpnt);
 
@@ -2190,6 +2213,44 @@ skip_fsfstatus:
         }
 }
 
+static int zfcp_fsf_set_data_dir(struct scsi_cmnd *scsi_cmnd, u32 *data_dir)
+{
+        switch (scsi_get_prot_op(scsi_cmnd)) {
+        case SCSI_PROT_NORMAL:
+                switch (scsi_cmnd->sc_data_direction) {
+                case DMA_NONE:
+                        *data_dir = FSF_DATADIR_CMND;
+                        break;
+                case DMA_FROM_DEVICE:
+                        *data_dir = FSF_DATADIR_READ;
+                        break;
+                case DMA_TO_DEVICE:
+                        *data_dir = FSF_DATADIR_WRITE;
+                        break;
+                case DMA_BIDIRECTIONAL:
+                        return -EINVAL;
+                }
+                break;
+
+        case SCSI_PROT_READ_STRIP:
+                *data_dir = FSF_DATADIR_DIF_READ_STRIP;
+                break;
+        case SCSI_PROT_WRITE_INSERT:
+                *data_dir = FSF_DATADIR_DIF_WRITE_INSERT;
+                break;
+        case SCSI_PROT_READ_PASS:
+                *data_dir = FSF_DATADIR_DIF_READ_CONVERT;
+                break;
+        case SCSI_PROT_WRITE_PASS:
+                *data_dir = FSF_DATADIR_DIF_WRITE_CONVERT;
+                break;
+        default:
+                return -EINVAL;
+        }
+
+        return 0;
+}
+
 /**
  * zfcp_fsf_send_fcp_command_task - initiate an FCP command (for a SCSI command)
  * @unit: unit where command is sent to
@@ -2201,9 +2262,10 @@ int zfcp_fsf_send_fcp_command_task(struct zfcp_unit *unit,
         struct zfcp_fsf_req *req;
         struct fcp_cmnd *fcp_cmnd;
         unsigned int sbtype = SBAL_FLAGS0_TYPE_READ;
-        int real_bytes, retval = -EIO;
+        int real_bytes, retval = -EIO, dix_bytes = 0;
         struct zfcp_adapter *adapter = unit->port->adapter;
         struct zfcp_qdio *qdio = adapter->qdio;
+        struct fsf_qtcb_bottom_io *io;
 
         if (unlikely(!(atomic_read(&unit->status) &
                        ZFCP_STATUS_COMMON_UNBLOCKED)))
@@ -2226,46 +2288,46 @@ int zfcp_fsf_send_fcp_command_task(struct zfcp_unit *unit,
                 goto out;
         }
 
+        scsi_cmnd->host_scribble = (unsigned char *) req->req_id;
+
+        io = &req->qtcb->bottom.io;
         req->status |= ZFCP_STATUS_FSFREQ_CLEANUP;
         req->unit = unit;
         req->data = scsi_cmnd;
         req->handler = zfcp_fsf_send_fcp_command_handler;
         req->qtcb->header.lun_handle = unit->handle;
         req->qtcb->header.port_handle = unit->port->handle;
-        req->qtcb->bottom.io.service_class = FSF_CLASS_3;
-        req->qtcb->bottom.io.fcp_cmnd_length = FCP_CMND_LEN;
+        io->service_class = FSF_CLASS_3;
+        io->fcp_cmnd_length = FCP_CMND_LEN;
 
-        scsi_cmnd->host_scribble = (unsigned char *) req->req_id;
-
-        /*
-         * set depending on data direction:
-         *      data direction bits in SBALE (SB Type)
-         *      data direction bits in QTCB
-         */
-        switch (scsi_cmnd->sc_data_direction) {
-        case DMA_NONE:
-                req->qtcb->bottom.io.data_direction = FSF_DATADIR_CMND;
-                break;
-        case DMA_FROM_DEVICE:
-                req->qtcb->bottom.io.data_direction = FSF_DATADIR_READ;
-                break;
-        case DMA_TO_DEVICE:
-                req->qtcb->bottom.io.data_direction = FSF_DATADIR_WRITE;
-                break;
-        case DMA_BIDIRECTIONAL:
-                goto failed_scsi_cmnd;
+        if (scsi_get_prot_op(scsi_cmnd) != SCSI_PROT_NORMAL) {
+                io->data_block_length = scsi_cmnd->device->sector_size;
+                io->ref_tag_value = scsi_get_lba(scsi_cmnd) & 0xFFFFFFFF;
         }
 
+        zfcp_fsf_set_data_dir(scsi_cmnd, &io->data_direction);
+
         get_device(&unit->dev);
 
         fcp_cmnd = (struct fcp_cmnd *) &req->qtcb->bottom.io.fcp_cmnd;
         zfcp_fc_scsi_to_fcp(fcp_cmnd, scsi_cmnd);
 
+        if (scsi_prot_sg_count(scsi_cmnd)) {
+                zfcp_qdio_set_data_div(qdio, &req->qdio_req,
+                                       scsi_prot_sg_count(scsi_cmnd));
+                dix_bytes = zfcp_qdio_sbals_from_sg(qdio, &req->qdio_req,
+                                                scsi_prot_sglist(scsi_cmnd));
+                io->prot_data_length = dix_bytes;
+        }
+
         real_bytes = zfcp_qdio_sbals_from_sg(qdio, &req->qdio_req,
                                              scsi_sglist(scsi_cmnd));
-        if (unlikely(real_bytes < 0))
+
+        if (unlikely(real_bytes < 0) || unlikely(dix_bytes < 0))
                 goto failed_scsi_cmnd;
 
+        zfcp_qdio_set_sbale_last(adapter->qdio, &req->qdio_req);
+
         retval = zfcp_fsf_req_send(req);
         if (unlikely(retval))
                 goto failed_scsi_cmnd;
@@ -2389,6 +2451,7 @@ struct zfcp_fsf_req *zfcp_fsf_control_file(struct zfcp_adapter *adapter,
                 zfcp_fsf_req_free(req);
                 goto out;
         }
+        zfcp_qdio_set_sbale_last(adapter->qdio, &req->qdio_req);
 
         zfcp_fsf_start_timer(req, ZFCP_FSF_REQUEST_TIMEOUT);
         retval = zfcp_fsf_req_send(req);
diff --git a/drivers/s390/scsi/zfcp_fsf.h b/drivers/s390/scsi/zfcp_fsf.h
index ca110e386761..db8c85382dca 100644
--- a/drivers/s390/scsi/zfcp_fsf.h
+++ b/drivers/s390/scsi/zfcp_fsf.h
@@ -80,11 +80,15 @@
 #define FSF_REQUEST_SIZE_TOO_LARGE              0x00000061
 #define FSF_RESPONSE_SIZE_TOO_LARGE             0x00000062
 #define FSF_SBAL_MISMATCH                       0x00000063
+#define FSF_INCONSISTENT_PROT_DATA              0x00000070
+#define FSF_INVALID_PROT_PARM                   0x00000071
+#define FSF_BLOCK_GUARD_CHECK_FAILURE           0x00000081
+#define FSF_APP_TAG_CHECK_FAILURE               0x00000082
+#define FSF_REF_TAG_CHECK_FAILURE               0x00000083
 #define FSF_ADAPTER_STATUS_AVAILABLE            0x000000AD
 #define FSF_UNKNOWN_COMMAND                     0x000000E2
 #define FSF_UNKNOWN_OP_SUBTYPE                  0x000000E3
 #define FSF_INVALID_COMMAND_OPTION              0x000000E5
-/* #define FSF_ERROR                             0x000000FF  */
 
 #define FSF_PROT_STATUS_QUAL_SIZE               16
 #define FSF_STATUS_QUALIFIER_SIZE               16
@@ -147,6 +151,13 @@
 #define FSF_DATADIR_WRITE                       0x00000001
 #define FSF_DATADIR_READ                        0x00000002
 #define FSF_DATADIR_CMND                        0x00000004
+#define FSF_DATADIR_DIF_WRITE_INSERT            0x00000009
+#define FSF_DATADIR_DIF_READ_STRIP              0x0000000a
+#define FSF_DATADIR_DIF_WRITE_CONVERT           0x0000000b
+#define FSF_DATADIR_DIF_READ_CONVERT            0X0000000c
+
+/* data protection control flags */
+#define FSF_APP_TAG_CHECK_ENABLE                0x10
 
 /* fc service class */
 #define FSF_CLASS_3                             0x00000003
@@ -162,6 +173,8 @@
 #define FSF_FEATURE_ELS_CT_CHAINED_SBALS        0x00000020
 #define FSF_FEATURE_UPDATE_ALERT                0x00000100
 #define FSF_FEATURE_MEASUREMENT_DATA            0x00000200
+#define FSF_FEATURE_DIF_PROT_TYPE1              0x00010000
+#define FSF_FEATURE_DIX_PROT_TCPIP              0x00020000
 
 /* host connection features */
 #define FSF_FEATURE_NPIV_MODE                   0x00000001
@@ -316,9 +329,14 @@ struct fsf_qtcb_header {
 struct fsf_qtcb_bottom_io {
         u32 data_direction;
         u32 service_class;
-        u8  res1[8];
+        u8  res1;
+        u8  data_prot_flags;
+        u16 app_tag_value;
+        u32 ref_tag_value;
         u32 fcp_cmnd_length;
-        u8  res2[12];
+        u32 data_block_length;
+        u32 prot_data_length;
+        u8  res2[4];
         u8  fcp_cmnd[FSF_FCP_CMND_SIZE];
         u8  fcp_rsp[FSF_FCP_RSP_SIZE];
         u8  res3[64];
diff --git a/drivers/s390/scsi/zfcp_qdio.c b/drivers/s390/scsi/zfcp_qdio.c
index c4559b29bebc..aceced8ec7e4 100644
--- a/drivers/s390/scsi/zfcp_qdio.c
+++ b/drivers/s390/scsi/zfcp_qdio.c
@@ -193,10 +193,6 @@ int zfcp_qdio_sbals_from_sg(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
                 bytes += sg->length;
         }
 
-        /* assume that no other SBALEs are to follow in the same SBAL */
-        sbale = zfcp_qdio_sbale_curr(qdio, q_req);
-        sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
-
         return bytes;
 }
 
diff --git a/drivers/s390/scsi/zfcp_qdio.h b/drivers/s390/scsi/zfcp_qdio.h
index 10d0df99dbf4..2297d8d3e947 100644
--- a/drivers/s390/scsi/zfcp_qdio.h
+++ b/drivers/s390/scsi/zfcp_qdio.h
@@ -215,4 +215,20 @@ void zfcp_qdio_sbal_limit(struct zfcp_qdio *qdio,
                                 QDIO_MAX_BUFFERS_PER_Q;
 }
 
+/**
+ * zfcp_qdio_set_data_div - set data division count
+ * @qdio: pointer to struct zfcp_qdio
+ * @q_req: The current zfcp_qdio_req
+ * @count: The data division count
+ */
+static inline
+void zfcp_qdio_set_data_div(struct zfcp_qdio *qdio,
+                            struct zfcp_qdio_req *q_req, u32 count)
+{
+        struct qdio_buffer_element *sbale;
+
+        sbale = &qdio->req_q[q_req->sbal_first]->element[0];
+        sbale->length = count;
+}
+
 #endif /* ZFCP_QDIO_H */
diff --git a/drivers/s390/scsi/zfcp_scsi.c b/drivers/s390/scsi/zfcp_scsi.c
index eb471a1723cd..cb000c9833bb 100644
--- a/drivers/s390/scsi/zfcp_scsi.c
+++ b/drivers/s390/scsi/zfcp_scsi.c
@@ -12,6 +12,7 @@
 #include <linux/types.h>
 #include <linux/slab.h>
 #include <scsi/fc/fc_fcp.h>
+#include <scsi/scsi_eh.h>
 #include <asm/atomic.h>
 #include "zfcp_ext.h"
 #include "zfcp_dbf.h"
@@ -22,6 +23,13 @@ static unsigned int default_depth = 32;
 module_param_named(queue_depth, default_depth, uint, 0600);
 MODULE_PARM_DESC(queue_depth, "Default queue depth for new SCSI devices");
 
+static bool enable_dif;
+
+#ifdef CONFIG_ZFCP_DIF
+module_param_named(dif, enable_dif, bool, 0600);
+MODULE_PARM_DESC(dif, "Enable DIF/DIX data integrity support");
+#endif
+
 static int zfcp_scsi_change_queue_depth(struct scsi_device *sdev, int depth,
                                         int reason)
 {
@@ -652,6 +660,51 @@ void zfcp_scsi_scan_work(struct work_struct *work)
         put_device(&unit->dev);
 }
 
+/**
+ * zfcp_scsi_set_prot - Configure DIF/DIX support in scsi_host
+ * @adapter: The adapter where to configure DIF/DIX for the SCSI host
+ */
+void zfcp_scsi_set_prot(struct zfcp_adapter *adapter)
+{
+        unsigned int mask = 0;
+        unsigned int data_div;
+        struct Scsi_Host *shost = adapter->scsi_host;
+
+        data_div = atomic_read(&adapter->status) &
+                   ZFCP_STATUS_ADAPTER_DATA_DIV_ENABLED;
+
+        if (enable_dif &&
+            adapter->adapter_features & FSF_FEATURE_DIF_PROT_TYPE1)
+                mask |= SHOST_DIF_TYPE1_PROTECTION;
+
+        if (enable_dif && data_div &&
+            adapter->adapter_features & FSF_FEATURE_DIX_PROT_TCPIP) {
+                mask |= SHOST_DIX_TYPE1_PROTECTION;
+                scsi_host_set_guard(shost, SHOST_DIX_GUARD_IP);
+                shost->sg_tablesize = ZFCP_QDIO_MAX_SBALES_PER_REQ / 2;
+                shost->max_sectors = ZFCP_QDIO_MAX_SBALES_PER_REQ * 8 / 2;
+        }
+
+        scsi_host_set_prot(shost, mask);
+}
+
+/**
+ * zfcp_scsi_dif_sense_error - Report DIF/DIX error as driver sense error
+ * @scmd: The SCSI command to report the error for
+ * @ascq: The ASCQ to put in the sense buffer
+ *
+ * See the error handling in sd_done for the sense codes used here.
+ * Set DID_SOFT_ERROR to retry the request, if possible.
+ */
+void zfcp_scsi_dif_sense_error(struct scsi_cmnd *scmd, int ascq)
+{
+        scsi_build_sense_buffer(1, scmd->sense_buffer,
+                                ILLEGAL_REQUEST, 0x10, ascq);
+        set_driver_byte(scmd, DRIVER_SENSE);
+        scmd->result |= SAM_STAT_CHECK_CONDITION;
+        set_host_byte(scmd, DID_SOFT_ERROR);
+}
+
 struct fc_function_template zfcp_transport_functions = {
         .show_starget_port_id = 1,
         .show_starget_port_name = 1,