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android-kvm / linux / 3a3b42bf89a9b90ae9ed2c57fdc378e5473a0ef9 / . / drivers / scsi / libfc / fc_fcp.c
blob: 970b54f653b70f15017638d14fb7ff037c17cd40 [file] [log] [blame]
/*
* Copyright(c) 2007 Intel Corporation. All rights reserved.
* Copyright(c) 2008 Red Hat, Inc. All rights reserved.
* Copyright(c) 2008 Mike Christie
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
*
* Maintained at www.Open-FCoE.org
*/
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/spinlock.h>
#include <linux/scatterlist.h>
#include <linux/err.h>
#include <linux/crc32.h>
#include <scsi/scsi_tcq.h>
#include <scsi/scsi.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/fc/fc_fc2.h>
#include <scsi/libfc.h>
#include <scsi/fc_encode.h>
#include "fc_libfc.h"
struct kmem_cache *scsi_pkt_cachep;
/* SRB state definitions */
#define FC_SRB_FREE 0 /* cmd is free */
#define FC_SRB_CMD_SENT (1 << 0) /* cmd has been sent */
#define FC_SRB_RCV_STATUS (1 << 1) /* response has arrived */
#define FC_SRB_ABORT_PENDING (1 << 2) /* cmd abort sent to device */
#define FC_SRB_ABORTED (1 << 3) /* abort acknowleged */
#define FC_SRB_DISCONTIG (1 << 4) /* non-sequential data recvd */
#define FC_SRB_COMPL (1 << 5) /* fc_io_compl has been run */
#define FC_SRB_FCP_PROCESSING_TMO (1 << 6) /* timer function processing */
#define FC_SRB_NOMEM (1 << 7) /* dropped to out of mem */
#define FC_SRB_READ (1 << 1)
#define FC_SRB_WRITE (1 << 0)
/*
* The SCp.ptr should be tested and set under the host lock. NULL indicates
* that the command has been retruned to the scsi layer.
*/
#define CMD_SP(Cmnd) ((struct fc_fcp_pkt *)(Cmnd)->SCp.ptr)
#define CMD_ENTRY_STATUS(Cmnd) ((Cmnd)->SCp.have_data_in)
#define CMD_COMPL_STATUS(Cmnd) ((Cmnd)->SCp.this_residual)
#define CMD_SCSI_STATUS(Cmnd) ((Cmnd)->SCp.Status)
#define CMD_RESID_LEN(Cmnd) ((Cmnd)->SCp.buffers_residual)
/**
* struct fc_fcp_internal - FCP layer internal data
* @scsi_pkt_pool: Memory pool to draw FCP packets from
* @scsi_pkt_queue: Current FCP packets
* @throttled: The FCP packet queue is throttled
*/
struct fc_fcp_internal {
mempool_t *scsi_pkt_pool;
struct list_head scsi_pkt_queue;
u8 throttled;
};
#define fc_get_scsi_internal(x) ((struct fc_fcp_internal *)(x)->scsi_priv)
/*
* function prototypes
* FC scsi I/O related functions
*/
static void fc_fcp_recv_data(struct fc_fcp_pkt *, struct fc_frame *);
static void fc_fcp_recv(struct fc_seq *, struct fc_frame *, void *);
static void fc_fcp_resp(struct fc_fcp_pkt *, struct fc_frame *);
static void fc_fcp_complete_locked(struct fc_fcp_pkt *);
static void fc_tm_done(struct fc_seq *, struct fc_frame *, void *);
static void fc_fcp_error(struct fc_fcp_pkt *, struct fc_frame *);
static void fc_timeout_error(struct fc_fcp_pkt *);
static void fc_fcp_timeout(unsigned long);
static void fc_fcp_rec(struct fc_fcp_pkt *);
static void fc_fcp_rec_error(struct fc_fcp_pkt *, struct fc_frame *);
static void fc_fcp_rec_resp(struct fc_seq *, struct fc_frame *, void *);
static void fc_io_compl(struct fc_fcp_pkt *);
static void fc_fcp_srr(struct fc_fcp_pkt *, enum fc_rctl, u32);
static void fc_fcp_srr_resp(struct fc_seq *, struct fc_frame *, void *);
static void fc_fcp_srr_error(struct fc_fcp_pkt *, struct fc_frame *);
/*
* command status codes
*/
#define FC_COMPLETE 0
#define FC_CMD_ABORTED 1
#define FC_CMD_RESET 2
#define FC_CMD_PLOGO 3
#define FC_SNS_RCV 4
#define FC_TRANS_ERR 5
#define FC_DATA_OVRRUN 6
#define FC_DATA_UNDRUN 7
#define FC_ERROR 8
#define FC_HRD_ERROR 9
#define FC_CMD_TIME_OUT 10
/*
* Error recovery timeout values.
*/
#define FC_SCSI_ER_TIMEOUT (10 * HZ)
#define FC_SCSI_TM_TOV (10 * HZ)
#define FC_SCSI_REC_TOV (2 * HZ)
#define FC_HOST_RESET_TIMEOUT (30 * HZ)
#define FC_MAX_ERROR_CNT 5
#define FC_MAX_RECOV_RETRY 3
#define FC_FCP_DFLT_QUEUE_DEPTH 32
/**
* fc_fcp_pkt_alloc() - Allocate a fcp_pkt
* @lport: The local port that the FCP packet is for
* @gfp: GFP flags for allocation
*
* Return value: fcp_pkt structure or null on allocation failure.
* Context: Can be called from process context, no lock is required.
*/
static struct fc_fcp_pkt *fc_fcp_pkt_alloc(struct fc_lport *lport, gfp_t gfp)
{
struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
struct fc_fcp_pkt *fsp;
fsp = mempool_alloc(si->scsi_pkt_pool, gfp);
if (fsp) {
memset(fsp, 0, sizeof(*fsp));
fsp->lp = lport;
atomic_set(&fsp->ref_cnt, 1);
init_timer(&fsp->timer);
INIT_LIST_HEAD(&fsp->list);
spin_lock_init(&fsp->scsi_pkt_lock);
}
return fsp;
}
/**
* fc_fcp_pkt_release() - Release hold on a fcp_pkt
* @fsp: The FCP packet to be released
*
* Context: Can be called from process or interrupt context,
* no lock is required.
*/
static void fc_fcp_pkt_release(struct fc_fcp_pkt *fsp)
{
if (atomic_dec_and_test(&fsp->ref_cnt)) {
struct fc_fcp_internal *si = fc_get_scsi_internal(fsp->lp);
mempool_free(fsp, si->scsi_pkt_pool);
}
}
/**
* fc_fcp_pkt_hold() - Hold a fcp_pkt
* @fsp: The FCP packet to be held
*/
static void fc_fcp_pkt_hold(struct fc_fcp_pkt *fsp)
{
atomic_inc(&fsp->ref_cnt);
}
/**
* fc_fcp_pkt_destory() - Release hold on a fcp_pkt
* @seq: The sequence that the FCP packet is on (required by destructor API)
* @fsp: The FCP packet to be released
*
* This routine is called by a destructor callback in the exch_seq_send()
* routine of the libfc Transport Template. The 'struct fc_seq' is a required
* argument even though it is not used by this routine.
*
* Context: No locking required.
*/
static void fc_fcp_pkt_destroy(struct fc_seq *seq, void *fsp)
{
fc_fcp_pkt_release(fsp);
}
/**
* fc_fcp_lock_pkt() - Lock a fcp_pkt and increase its reference count
* @fsp: The FCP packet to be locked and incremented
*
* We should only return error if we return a command to SCSI-ml before
* getting a response. This can happen in cases where we send a abort, but
* do not wait for the response and the abort and command can be passing
* each other on the wire/network-layer.
*
* Note: this function locks the packet and gets a reference to allow
* callers to call the completion function while the lock is held and
* not have to worry about the packets refcount.
*
* TODO: Maybe we should just have callers grab/release the lock and
* have a function that they call to verify the fsp and grab a ref if
* needed.
*/
static inline int fc_fcp_lock_pkt(struct fc_fcp_pkt *fsp)
{
spin_lock_bh(&fsp->scsi_pkt_lock);
if (fsp->state & FC_SRB_COMPL) {
spin_unlock_bh(&fsp->scsi_pkt_lock);
return -EPERM;
}
fc_fcp_pkt_hold(fsp);
return 0;
}
/**
* fc_fcp_unlock_pkt() - Release a fcp_pkt's lock and decrement its
* reference count
* @fsp: The FCP packet to be unlocked and decremented
*/
static inline void fc_fcp_unlock_pkt(struct fc_fcp_pkt *fsp)
{
spin_unlock_bh(&fsp->scsi_pkt_lock);
fc_fcp_pkt_release(fsp);
}
/**
* fc_fcp_timer_set() - Start a timer for a fcp_pkt
* @fsp: The FCP packet to start a timer for
* @delay: The timeout period for the timer
*/
static void fc_fcp_timer_set(struct fc_fcp_pkt *fsp, unsigned long delay)
{
if (!(fsp->state & FC_SRB_COMPL))
mod_timer(&fsp->timer, jiffies + delay);
}
/**
* fc_fcp_send_abort() - Send an abort for exchanges associated with a
* fcp_pkt
* @fsp: The FCP packet to abort exchanges on
*/
static int fc_fcp_send_abort(struct fc_fcp_pkt *fsp)
{
if (!fsp->seq_ptr)
return -EINVAL;
fsp->state |= FC_SRB_ABORT_PENDING;
return fsp->lp->tt.seq_exch_abort(fsp->seq_ptr, 0);
}
/**
* fc_fcp_retry_cmd() - Retry a fcp_pkt
* @fsp: The FCP packet to be retried
*
* Sets the status code to be FC_ERROR and then calls
* fc_fcp_complete_locked() which in turn calls fc_io_compl().
* fc_io_compl() will notify the SCSI-ml that the I/O is done.
* The SCSI-ml will retry the command.
*/
static void fc_fcp_retry_cmd(struct fc_fcp_pkt *fsp)
{
if (fsp->seq_ptr) {
fsp->lp->tt.exch_done(fsp->seq_ptr);
fsp->seq_ptr = NULL;
}
fsp->state &= ~FC_SRB_ABORT_PENDING;
fsp->io_status = 0;
fsp->status_code = FC_ERROR;
fc_fcp_complete_locked(fsp);
}
/**
* fc_fcp_ddp_setup() - Calls a LLD's ddp_setup routine to set up DDP context
* @fsp: The FCP packet that will manage the DDP frames
* @xid: The XID that will be used for the DDP exchange
*/
void fc_fcp_ddp_setup(struct fc_fcp_pkt *fsp, u16 xid)
{
struct fc_lport *lport;
if (!fsp)
return;
lport = fsp->lp;
if ((fsp->req_flags & FC_SRB_READ) &&
(lport->lro_enabled) && (lport->tt.ddp_setup)) {
if (lport->tt.ddp_setup(lport, xid, scsi_sglist(fsp->cmd),
scsi_sg_count(fsp->cmd)))
fsp->xfer_ddp = xid;
}
}
/**
* fc_fcp_ddp_done() - Calls a LLD's ddp_done routine to release any
* DDP related resources for a fcp_pkt
* @fsp: The FCP packet that DDP had been used on
*/
static void fc_fcp_ddp_done(struct fc_fcp_pkt *fsp)
{
struct fc_lport *lport;
if (!fsp)
return;
if (fsp->xfer_ddp == FC_XID_UNKNOWN)
return;
lport = fsp->lp;
if (lport->tt.ddp_done) {
fsp->xfer_len = lport->tt.ddp_done(lport, fsp->xfer_ddp);
fsp->xfer_ddp = FC_XID_UNKNOWN;
}
}
/**
* fc_fcp_recv_data() - Handler for receiving SCSI-FCP data from a target
* @fsp: The FCP packet the data is on
* @fp: The data frame
*/
static void fc_fcp_recv_data(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
{
struct scsi_cmnd *sc = fsp->cmd;
struct fc_lport *lport = fsp->lp;
struct fcoe_dev_stats *stats;
struct fc_frame_header *fh;
size_t start_offset;
size_t offset;
u32 crc;
u32 copy_len = 0;
size_t len;
void *buf;
struct scatterlist *sg;
u32 nents;
fh = fc_frame_header_get(fp);
offset = ntohl(fh->fh_parm_offset);
start_offset = offset;
len = fr_len(fp) - sizeof(*fh);
buf = fc_frame_payload_get(fp, 0);
/* if this I/O is ddped, update xfer len */
fc_fcp_ddp_done(fsp);
if (offset + len > fsp->data_len) {
/* this should never happen */
if ((fr_flags(fp) & FCPHF_CRC_UNCHECKED) &&
fc_frame_crc_check(fp))
goto crc_err;
FC_FCP_DBG(fsp, "data received past end. len %zx offset %zx "
"data_len %x\n", len, offset, fsp->data_len);
fc_fcp_retry_cmd(fsp);
return;
}
if (offset != fsp->xfer_len)
fsp->state |= FC_SRB_DISCONTIG;
sg = scsi_sglist(sc);
nents = scsi_sg_count(sc);
if (!(fr_flags(fp) & FCPHF_CRC_UNCHECKED)) {
copy_len = fc_copy_buffer_to_sglist(buf, len, sg, &nents,
&offset, KM_SOFTIRQ0, NULL);
} else {
crc = crc32(~0, (u8 *) fh, sizeof(*fh));
copy_len = fc_copy_buffer_to_sglist(buf, len, sg, &nents,
&offset, KM_SOFTIRQ0, &crc);
buf = fc_frame_payload_get(fp, 0);
if (len % 4)
crc = crc32(crc, buf + len, 4 - (len % 4));
if (~crc != le32_to_cpu(fr_crc(fp))) {
crc_err:
stats = fc_lport_get_stats(lport);
stats->ErrorFrames++;
/* FIXME - per cpu count, not total count! */
if (stats->InvalidCRCCount++ < 5)
printk(KERN_WARNING "libfc: CRC error on data "
"frame for port (%6x)\n",
fc_host_port_id(lport->host));
/*
* Assume the frame is total garbage.
* We may have copied it over the good part
* of the buffer.
* If so, we need to retry the entire operation.
* Otherwise, ignore it.
*/
if (fsp->state & FC_SRB_DISCONTIG)
fc_fcp_retry_cmd(fsp);
return;
}
}
if (fsp->xfer_contig_end == start_offset)
fsp->xfer_contig_end += copy_len;
fsp->xfer_len += copy_len;
/*
* In the very rare event that this data arrived after the response
* and completes the transfer, call the completion handler.
*/
if (unlikely(fsp->state & FC_SRB_RCV_STATUS) &&
fsp->xfer_len == fsp->data_len - fsp->scsi_resid)
fc_fcp_complete_locked(fsp);
}
/**
* fc_fcp_send_data() - Send SCSI data to a target
* @fsp: The FCP packet the data is on
* @sp: The sequence the data is to be sent on
* @offset: The starting offset for this data request
* @seq_blen: The burst length for this data request
*
* Called after receiving a Transfer Ready data descriptor.
* If the LLD is capable of sequence offload then send down the
* seq_blen ammount of data in single frame, otherwise send
* multiple frames of the maximum frame payload supported by
* the target port.
*/
static int fc_fcp_send_data(struct fc_fcp_pkt *fsp, struct fc_seq *seq,
size_t offset, size_t seq_blen)
{
struct fc_exch *ep;
struct scsi_cmnd *sc;
struct scatterlist *sg;
struct fc_frame *fp = NULL;
struct fc_lport *lport = fsp->lp;
size_t remaining;
size_t t_blen;
size_t tlen;
size_t sg_bytes;
size_t frame_offset, fh_parm_offset;
int error;
void *data = NULL;
void *page_addr;
int using_sg = lport->sg_supp;
u32 f_ctl;
WARN_ON(seq_blen <= 0);
if (unlikely(offset + seq_blen > fsp->data_len)) {
/* this should never happen */
FC_FCP_DBG(fsp, "xfer-ready past end. seq_blen %zx "
"offset %zx\n", seq_blen, offset);
fc_fcp_send_abort(fsp);
return 0;
} else if (offset != fsp->xfer_len) {
/* Out of Order Data Request - no problem, but unexpected. */
FC_FCP_DBG(fsp, "xfer-ready non-contiguous. "
"seq_blen %zx offset %zx\n", seq_blen, offset);
}
/*
* if LLD is capable of seq_offload then set transport
* burst length (t_blen) to seq_blen, otherwise set t_blen
* to max FC frame payload previously set in fsp->max_payload.
*/
t_blen = fsp->max_payload;
if (lport->seq_offload) {
t_blen = min(seq_blen, (size_t)lport->lso_max);
FC_FCP_DBG(fsp, "fsp=%p:lso:blen=%zx lso_max=0x%x t_blen=%zx\n",
fsp, seq_blen, lport->lso_max, t_blen);
}
WARN_ON(t_blen < FC_MIN_MAX_PAYLOAD);
if (t_blen > 512)
t_blen &= ~(512 - 1); /* round down to block size */
WARN_ON(t_blen < FC_MIN_MAX_PAYLOAD); /* won't go below 256 */
sc = fsp->cmd;
remaining = seq_blen;
fh_parm_offset = frame_offset = offset;
tlen = 0;
seq = lport->tt.seq_start_next(seq);
f_ctl = FC_FC_REL_OFF;
WARN_ON(!seq);
sg = scsi_sglist(sc);
while (remaining > 0 && sg) {
if (offset >= sg->length) {
offset -= sg->length;
sg = sg_next(sg);
continue;
}
if (!fp) {
tlen = min(t_blen, remaining);
/*
* TODO. Temporary workaround. fc_seq_send() can't
* handle odd lengths in non-linear skbs.
* This will be the final fragment only.
*/
if (tlen % 4)
using_sg = 0;
if (using_sg) {
fp = _fc_frame_alloc(lport, 0);
if (!fp)
return -ENOMEM;
} else {
fp = fc_frame_alloc(lport, tlen);
if (!fp)
return -ENOMEM;
data = (void *)(fr_hdr(fp)) +
sizeof(struct fc_frame_header);
}
fh_parm_offset = frame_offset;
fr_max_payload(fp) = fsp->max_payload;
}
sg_bytes = min(tlen, sg->length - offset);
if (using_sg) {
get_page(sg_page(sg));
skb_fill_page_desc(fp_skb(fp),
skb_shinfo(fp_skb(fp))->nr_frags,
sg_page(sg), sg->offset + offset,
sg_bytes);
fp_skb(fp)->data_len += sg_bytes;
fr_len(fp) += sg_bytes;
fp_skb(fp)->truesize += PAGE_SIZE;
} else {
size_t off = offset + sg->offset;
/*
* The scatterlist item may be bigger than PAGE_SIZE,
* but we must not cross pages inside the kmap.
*/
sg_bytes = min(sg_bytes, (size_t) (PAGE_SIZE -
(off & ~PAGE_MASK)));
page_addr = kmap_atomic(sg_page(sg) +
(off >> PAGE_SHIFT),
KM_SOFTIRQ0);
memcpy(data, (char *)page_addr + (off & ~PAGE_MASK),
sg_bytes);
kunmap_atomic(page_addr, KM_SOFTIRQ0);
data += sg_bytes;
}
offset += sg_bytes;
frame_offset += sg_bytes;
tlen -= sg_bytes;
remaining -= sg_bytes;
if ((skb_shinfo(fp_skb(fp))->nr_frags < FC_FRAME_SG_LEN) &&
(tlen))
continue;
/*
* Send sequence with transfer sequence initiative in case
* this is last FCP frame of the sequence.
*/
if (remaining == 0)
f_ctl |= FC_FC_SEQ_INIT | FC_FC_END_SEQ;
ep = fc_seq_exch(seq);
fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid,
FC_TYPE_FCP, f_ctl, fh_parm_offset);
/*
* send fragment using for a sequence.
*/
error = lport->tt.seq_send(lport, seq, fp);
if (error) {
WARN_ON(1); /* send error should be rare */
fc_fcp_retry_cmd(fsp);
return 0;
}
fp = NULL;
}
fsp->xfer_len += seq_blen; /* premature count? */
return 0;
}
/**
* fc_fcp_abts_resp() - Send an ABTS response
* @fsp: The FCP packet that is being aborted
* @fp: The response frame
*/
static void fc_fcp_abts_resp(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
{
int ba_done = 1;
struct fc_ba_rjt *brp;
struct fc_frame_header *fh;
fh = fc_frame_header_get(fp);
switch (fh->fh_r_ctl) {
case FC_RCTL_BA_ACC:
break;
case FC_RCTL_BA_RJT:
brp = fc_frame_payload_get(fp, sizeof(*brp));
if (brp && brp->br_reason == FC_BA_RJT_LOG_ERR)
break;
/* fall thru */
default:
/*
* we will let the command timeout
* and scsi-ml recover in this case,
* therefore cleared the ba_done flag.
*/
ba_done = 0;
}
if (ba_done) {
fsp->state |= FC_SRB_ABORTED;
fsp->state &= ~FC_SRB_ABORT_PENDING;
if (fsp->wait_for_comp)
complete(&fsp->tm_done);
else
fc_fcp_complete_locked(fsp);
}
}
/**
* fc_fcp_reduce_can_queue() - Reduce the can_queue value for a local port
* @lport: The local port to reduce can_queue on
*
* If we are getting memory allocation failures, then we may
* be trying to execute too many commands. We let the running
* commands complete or timeout, then try again with a reduced
* can_queue. Eventually we will hit the point where we run
* on all reserved structs.
*/
static void fc_fcp_reduce_can_queue(struct fc_lport *lport)
{
struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
unsigned long flags;
int can_queue;
spin_lock_irqsave(lport->host->host_lock, flags);
if (si->throttled)
goto done;
si->throttled = 1;
can_queue = lport->host->can_queue;
can_queue >>= 1;
if (!can_queue)
can_queue = 1;
lport->host->can_queue = can_queue;
shost_printk(KERN_ERR, lport->host, "libfc: Could not allocate frame.\n"
"Reducing can_queue to %d.\n", can_queue);
done:
spin_unlock_irqrestore(lport->host->host_lock, flags);
}
/**
* fc_fcp_recv() - Reveive an FCP frame
* @seq: The sequence the frame is on
* @fp: The received frame
* @arg: The related FCP packet
*
* Context: Called from Soft IRQ context. Can not be called
* holding the FCP packet list lock.
*/
static void fc_fcp_recv(struct fc_seq *seq, struct fc_frame *fp, void *arg)
{
struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)arg;
struct fc_lport *lport = fsp->lp;
struct fc_frame_header *fh;
struct fcp_txrdy *dd;
u8 r_ctl;
int rc = 0;
if (IS_ERR(fp))
goto errout;
fh = fc_frame_header_get(fp);
r_ctl = fh->fh_r_ctl;
if (!(lport->state & LPORT_ST_READY))
goto out;
if (fc_fcp_lock_pkt(fsp))
goto out;
fsp->last_pkt_time = jiffies;
if (fh->fh_type == FC_TYPE_BLS) {
fc_fcp_abts_resp(fsp, fp);
goto unlock;
}
if (fsp->state & (FC_SRB_ABORTED | FC_SRB_ABORT_PENDING))
goto unlock;
if (r_ctl == FC_RCTL_DD_DATA_DESC) {
/*
* received XFER RDY from the target
* need to send data to the target
*/
WARN_ON(fr_flags(fp) & FCPHF_CRC_UNCHECKED);
dd = fc_frame_payload_get(fp, sizeof(*dd));
WARN_ON(!dd);
rc = fc_fcp_send_data(fsp, seq,
(size_t) ntohl(dd->ft_data_ro),
(size_t) ntohl(dd->ft_burst_len));
if (!rc)
seq->rec_data = fsp->xfer_len;
else if (rc == -ENOMEM)
fsp->state |= FC_SRB_NOMEM;
} else if (r_ctl == FC_RCTL_DD_SOL_DATA) {
/*
* received a DATA frame
* next we will copy the data to the system buffer
*/
WARN_ON(fr_len(fp) < sizeof(*fh)); /* len may be 0 */
fc_fcp_recv_data(fsp, fp);
seq->rec_data = fsp->xfer_contig_end;
} else if (r_ctl == FC_RCTL_DD_CMD_STATUS) {
WARN_ON(fr_flags(fp) & FCPHF_CRC_UNCHECKED);
fc_fcp_resp(fsp, fp);
} else {
FC_FCP_DBG(fsp, "unexpected frame. r_ctl %x\n", r_ctl);
}
unlock:
fc_fcp_unlock_pkt(fsp);
out:
fc_frame_free(fp);
errout:
if (IS_ERR(fp))
fc_fcp_error(fsp, fp);
else if (rc == -ENOMEM)
fc_fcp_reduce_can_queue(lport);
}
/**
* fc_fcp_resp() - Handler for FCP responses
* @fsp: The FCP packet the response is for
* @fp: The response frame
*/
static void fc_fcp_resp(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
{
struct fc_frame_header *fh;
struct fcp_resp *fc_rp;
struct fcp_resp_ext *rp_ex;
struct fcp_resp_rsp_info *fc_rp_info;
u32 plen;
u32 expected_len;
u32 respl = 0;
u32 snsl = 0;
u8 flags = 0;
plen = fr_len(fp);
fh = (struct fc_frame_header *)fr_hdr(fp);
if (unlikely(plen < sizeof(*fh) + sizeof(*fc_rp)))
goto len_err;
plen -= sizeof(*fh);
fc_rp = (struct fcp_resp *)(fh + 1);
fsp->cdb_status = fc_rp->fr_status;
flags = fc_rp->fr_flags;
fsp->scsi_comp_flags = flags;
expected_len = fsp->data_len;
/* if ddp, update xfer len */
fc_fcp_ddp_done(fsp);
if (unlikely((flags & ~FCP_CONF_REQ) || fc_rp->fr_status)) {
rp_ex = (void *)(fc_rp + 1);
if (flags & (FCP_RSP_LEN_VAL | FCP_SNS_LEN_VAL)) {
if (plen < sizeof(*fc_rp) + sizeof(*rp_ex))
goto len_err;
fc_rp_info = (struct fcp_resp_rsp_info *)(rp_ex + 1);
if (flags & FCP_RSP_LEN_VAL) {
respl = ntohl(rp_ex->fr_rsp_len);
if (respl != sizeof(*fc_rp_info))
goto len_err;
if (fsp->wait_for_comp) {
/* Abuse cdb_status for rsp code */
fsp->cdb_status = fc_rp_info->rsp_code;
complete(&fsp->tm_done);
/*
* tmfs will not have any scsi cmd so
* exit here
*/
return;
} else
goto err;
}
if (flags & FCP_SNS_LEN_VAL) {
snsl = ntohl(rp_ex->fr_sns_len);
if (snsl > SCSI_SENSE_BUFFERSIZE)
snsl = SCSI_SENSE_BUFFERSIZE;
memcpy(fsp->cmd->sense_buffer,
(char *)fc_rp_info + respl, snsl);
}
}
if (flags & (FCP_RESID_UNDER | FCP_RESID_OVER)) {
if (plen < sizeof(*fc_rp) + sizeof(rp_ex->fr_resid))
goto len_err;
if (flags & FCP_RESID_UNDER) {
fsp->scsi_resid = ntohl(rp_ex->fr_resid);
/*
* The cmnd->underflow is the minimum number of
* bytes that must be transfered for this
* command. Provided a sense condition is not
* present, make sure the actual amount
* transferred is at least the underflow value
* or fail.
*/
if (!(flags & FCP_SNS_LEN_VAL) &&
(fc_rp->fr_status == 0) &&
(scsi_bufflen(fsp->cmd) -
fsp->scsi_resid) < fsp->cmd->underflow)
goto err;
expected_len -= fsp->scsi_resid;
} else {
fsp->status_code = FC_ERROR;
}
}
}
fsp->state |= FC_SRB_RCV_STATUS;
/*
* Check for missing or extra data frames.
*/
if (unlikely(fsp->xfer_len != expected_len)) {
if (fsp->xfer_len < expected_len) {
/*
* Some data may be queued locally,
* Wait a at least one jiffy to see if it is delivered.
* If this expires without data, we may do SRR.
*/
fc_fcp_timer_set(fsp, 2);
return;
}
fsp->status_code = FC_DATA_OVRRUN;
FC_FCP_DBG(fsp, "tgt %6x xfer len %zx greater than expected, "
"len %x, data len %x\n",
fsp->rport->port_id,
fsp->xfer_len, expected_len, fsp->data_len);
}
fc_fcp_complete_locked(fsp);
return;
len_err:
FC_FCP_DBG(fsp, "short FCP response. flags 0x%x len %u respl %u "
"snsl %u\n", flags, fr_len(fp), respl, snsl);
err:
fsp->status_code = FC_ERROR;
fc_fcp_complete_locked(fsp);
}
/**
* fc_fcp_complete_locked() - Complete processing of a fcp_pkt with the
* fcp_pkt lock held
* @fsp: The FCP packet to be completed
*
* This function may sleep if a timer is pending. The packet lock must be
* held, and the host lock must not be held.
*/
static void fc_fcp_complete_locked(struct fc_fcp_pkt *fsp)
{
struct fc_lport *lport = fsp->lp;
struct fc_seq *seq;
struct fc_exch *ep;
u32 f_ctl;
if (fsp->state & FC_SRB_ABORT_PENDING)
return;
if (fsp->state & FC_SRB_ABORTED) {
if (!fsp->status_code)
fsp->status_code = FC_CMD_ABORTED;
} else {
/*
* Test for transport underrun, independent of response
* underrun status.
*/
if (fsp->xfer_len < fsp->data_len && !fsp->io_status &&
(!(fsp->scsi_comp_flags & FCP_RESID_UNDER) ||
fsp->xfer_len < fsp->data_len - fsp->scsi_resid)) {
fsp->status_code = FC_DATA_UNDRUN;
fsp->io_status = 0;
}
}
seq = fsp->seq_ptr;
if (seq) {
fsp->seq_ptr = NULL;
if (unlikely(fsp->scsi_comp_flags & FCP_CONF_REQ)) {
struct fc_frame *conf_frame;
struct fc_seq *csp;
csp = lport->tt.seq_start_next(seq);
conf_frame = fc_frame_alloc(fsp->lp, 0);
if (conf_frame) {
f_ctl = FC_FC_SEQ_INIT;
f_ctl |= FC_FC_LAST_SEQ | FC_FC_END_SEQ;
ep = fc_seq_exch(seq);
fc_fill_fc_hdr(conf_frame, FC_RCTL_DD_SOL_CTL,
ep->did, ep->sid,
FC_TYPE_FCP, f_ctl, 0);
lport->tt.seq_send(lport, csp, conf_frame);
}
}
lport->tt.exch_done(seq);
}
fc_io_compl(fsp);
}
/**
* fc_fcp_cleanup_cmd() - Cancel the active exchange on a fcp_pkt
* @fsp: The FCP packet whose exchanges should be canceled
* @error: The reason for the cancellation
*/
static void fc_fcp_cleanup_cmd(struct fc_fcp_pkt *fsp, int error)
{
struct fc_lport *lport = fsp->lp;
if (fsp->seq_ptr) {
lport->tt.exch_done(fsp->seq_ptr);
fsp->seq_ptr = NULL;
}
fsp->status_code = error;
}
/**
* fc_fcp_cleanup_each_cmd() - Cancel all exchanges on a local port
* @lport: The local port whose exchanges should be canceled
* @id: The target's ID
* @lun: The LUN
* @error: The reason for cancellation
*
* If lun or id is -1, they are ignored.
*/
static void fc_fcp_cleanup_each_cmd(struct fc_lport *lport, unsigned int id,
unsigned int lun, int error)
{
struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
struct fc_fcp_pkt *fsp;
struct scsi_cmnd *sc_cmd;
unsigned long flags;
spin_lock_irqsave(lport->host->host_lock, flags);
restart:
list_for_each_entry(fsp, &si->scsi_pkt_queue, list) {
sc_cmd = fsp->cmd;
if (id != -1 && scmd_id(sc_cmd) != id)
continue;
if (lun != -1 && sc_cmd->device->lun != lun)
continue;
fc_fcp_pkt_hold(fsp);
spin_unlock_irqrestore(lport->host->host_lock, flags);
if (!fc_fcp_lock_pkt(fsp)) {
fc_fcp_cleanup_cmd(fsp, error);
fc_io_compl(fsp);
fc_fcp_unlock_pkt(fsp);
}
fc_fcp_pkt_release(fsp);
spin_lock_irqsave(lport->host->host_lock, flags);
/*
* while we dropped the lock multiple pkts could
* have been released, so we have to start over.
*/
goto restart;
}
spin_unlock_irqrestore(lport->host->host_lock, flags);
}
/**
* fc_fcp_abort_io() - Abort all FCP-SCSI exchanges on a local port
* @lport: The local port whose exchanges are to be aborted
*/
static void fc_fcp_abort_io(struct fc_lport *lport)
{
fc_fcp_cleanup_each_cmd(lport, -1, -1, FC_HRD_ERROR);
}
/**
* fc_fcp_pkt_send() - Send a fcp_pkt
* @lport: The local port to send the FCP packet on
* @fsp: The FCP packet to send
*
* Return: Zero for success and -1 for failure
* Locks: Called with the host lock and irqs disabled.
*/
static int fc_fcp_pkt_send(struct fc_lport *lport, struct fc_fcp_pkt *fsp)
{
struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
int rc;
fsp->cmd->SCp.ptr = (char *)fsp;
fsp->cdb_cmd.fc_dl = htonl(fsp->data_len);
fsp->cdb_cmd.fc_flags = fsp->req_flags & ~FCP_CFL_LEN_MASK;
int_to_scsilun(fsp->cmd->device->lun,
(struct scsi_lun *)fsp->cdb_cmd.fc_lun);
memcpy(fsp->cdb_cmd.fc_cdb, fsp->cmd->cmnd, fsp->cmd->cmd_len);
list_add_tail(&fsp->list, &si->scsi_pkt_queue);
spin_unlock_irq(lport->host->host_lock);
rc = lport->tt.fcp_cmd_send(lport, fsp, fc_fcp_recv);
spin_lock_irq(lport->host->host_lock);
if (rc)
list_del(&fsp->list);
return rc;
}
/**
* fc_fcp_cmd_send() - Send a FCP command
* @lport: The local port to send the command on
* @fsp: The FCP packet the command is on
* @resp: The handler for the response
*/
static int fc_fcp_cmd_send(struct fc_lport *lport, struct fc_fcp_pkt *fsp,
void (*resp)(struct fc_seq *,
struct fc_frame *fp,
void *arg))
{
struct fc_frame *fp;
struct fc_seq *seq;
struct fc_rport *rport;
struct fc_rport_libfc_priv *rpriv;
const size_t len = sizeof(fsp->cdb_cmd);
int rc = 0;
if (fc_fcp_lock_pkt(fsp))
return 0;
fp = fc_frame_alloc(lport, sizeof(fsp->cdb_cmd));
if (!fp) {
rc = -1;
goto unlock;
}
memcpy(fc_frame_payload_get(fp, len), &fsp->cdb_cmd, len);
fr_fsp(fp) = fsp;
rport = fsp->rport;
fsp->max_payload = rport->maxframe_size;
rpriv = rport->dd_data;
fc_fill_fc_hdr(fp, FC_RCTL_DD_UNSOL_CMD, rport->port_id,
fc_host_port_id(rpriv->local_port->host), FC_TYPE_FCP,
FC_FC_FIRST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
seq = lport->tt.exch_seq_send(lport, fp, resp, fc_fcp_pkt_destroy,
fsp, 0);
if (!seq) {
rc = -1;
goto unlock;
}
fsp->last_pkt_time = jiffies;
fsp->seq_ptr = seq;
fc_fcp_pkt_hold(fsp); /* hold for fc_fcp_pkt_destroy */
setup_timer(&fsp->timer, fc_fcp_timeout, (unsigned long)fsp);
fc_fcp_timer_set(fsp,
(fsp->tgt_flags & FC_RP_FLAGS_REC_SUPPORTED) ?
FC_SCSI_REC_TOV : FC_SCSI_ER_TIMEOUT);
unlock:
fc_fcp_unlock_pkt(fsp);
return rc;
}
/**
* fc_fcp_error() - Handler for FCP layer errors
* @fsp: The FCP packet the error is on
* @fp: The frame that has errored
*/
static void fc_fcp_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
{
int error = PTR_ERR(fp);
if (fc_fcp_lock_pkt(fsp))
return;
if (error == -FC_EX_CLOSED) {
fc_fcp_retry_cmd(fsp);
goto unlock;
}
/*
* clear abort pending, because the lower layer
* decided to force completion.
*/
fsp->state &= ~FC_SRB_ABORT_PENDING;
fsp->status_code = FC_CMD_PLOGO;
fc_fcp_complete_locked(fsp);
unlock:
fc_fcp_unlock_pkt(fsp);
}
/**
* fc_fcp_pkt_abort() - Abort a fcp_pkt
* @fsp: The FCP packet to abort on
*
* Called to send an abort and then wait for abort completion
*/
static int fc_fcp_pkt_abort(struct fc_fcp_pkt *fsp)
{
int rc = FAILED;
if (fc_fcp_send_abort(fsp))
return FAILED;
init_completion(&fsp->tm_done);
fsp->wait_for_comp = 1;
spin_unlock_bh(&fsp->scsi_pkt_lock);
rc = wait_for_completion_timeout(&fsp->tm_done, FC_SCSI_TM_TOV);
spin_lock_bh(&fsp->scsi_pkt_lock);
fsp->wait_for_comp = 0;
if (!rc) {
FC_FCP_DBG(fsp, "target abort cmd failed\n");
rc = FAILED;
} else if (fsp->state & FC_SRB_ABORTED) {
FC_FCP_DBG(fsp, "target abort cmd passed\n");
rc = SUCCESS;
fc_fcp_complete_locked(fsp);
}
return rc;
}
/**
* fc_lun_reset_send() - Send LUN reset command
* @data: The FCP packet that identifies the LUN to be reset
*/
static void fc_lun_reset_send(unsigned long data)
{
struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)data;
struct fc_lport *lport = fsp->lp;
if (lport->tt.fcp_cmd_send(lport, fsp, fc_tm_done)) {
if (fsp->recov_retry++ >= FC_MAX_RECOV_RETRY)
return;
if (fc_fcp_lock_pkt(fsp))
return;
setup_timer(&fsp->timer, fc_lun_reset_send, (unsigned long)fsp);
fc_fcp_timer_set(fsp, FC_SCSI_REC_TOV);
fc_fcp_unlock_pkt(fsp);
}
}
/**
* fc_lun_reset() - Send a LUN RESET command to a device
* and wait for the reply
* @lport: The local port to sent the comand on
* @fsp: The FCP packet that identifies the LUN to be reset
* @id: The SCSI command ID
* @lun: The LUN ID to be reset
*/
static int fc_lun_reset(struct fc_lport *lport, struct fc_fcp_pkt *fsp,
unsigned int id, unsigned int lun)
{
int rc;
fsp->cdb_cmd.fc_dl = htonl(fsp->data_len);
fsp->cdb_cmd.fc_tm_flags = FCP_TMF_LUN_RESET;
int_to_scsilun(lun, (struct scsi_lun *)fsp->cdb_cmd.fc_lun);
fsp->wait_for_comp = 1;
init_completion(&fsp->tm_done);
fc_lun_reset_send((unsigned long)fsp);
/*
* wait for completion of reset
* after that make sure all commands are terminated
*/
rc = wait_for_completion_timeout(&fsp->tm_done, FC_SCSI_TM_TOV);
spin_lock_bh(&fsp->scsi_pkt_lock);
fsp->state |= FC_SRB_COMPL;
spin_unlock_bh(&fsp->scsi_pkt_lock);
del_timer_sync(&fsp->timer);
spin_lock_bh(&fsp->scsi_pkt_lock);
if (fsp->seq_ptr) {
lport->tt.exch_done(fsp->seq_ptr);
fsp->seq_ptr = NULL;
}
fsp->wait_for_comp = 0;
spin_unlock_bh(&fsp->scsi_pkt_lock);
if (!rc) {
FC_SCSI_DBG(lport, "lun reset failed\n");
return FAILED;
}
/* cdb_status holds the tmf's rsp code */
if (fsp->cdb_status != FCP_TMF_CMPL)
return FAILED;
FC_SCSI_DBG(lport, "lun reset to lun %u completed\n", lun);
fc_fcp_cleanup_each_cmd(lport, id, lun, FC_CMD_ABORTED);
return SUCCESS;
}
/**
* fc_tm_done() - Task Managment response handler
* @seq: The sequence that the response is on
* @fp: The response frame
* @arg: The FCP packet the response is for
*/
static void fc_tm_done(struct fc_seq *seq, struct fc_frame *fp, void *arg)
{
struct fc_fcp_pkt *fsp = arg;
struct fc_frame_header *fh;
if (IS_ERR(fp)) {
/*
* If there is an error just let it timeout or wait
* for TMF to be aborted if it timedout.
*
* scsi-eh will escalate for when either happens.
*/
return;
}
if (fc_fcp_lock_pkt(fsp))
return;
/*
* raced with eh timeout handler.
*/
if (!fsp->seq_ptr || !fsp->wait_for_comp) {
spin_unlock_bh(&fsp->scsi_pkt_lock);
return;
}
fh = fc_frame_header_get(fp);
if (fh->fh_type != FC_TYPE_BLS)
fc_fcp_resp(fsp, fp);
fsp->seq_ptr = NULL;
fsp->lp->tt.exch_done(seq);
fc_frame_free(fp);
fc_fcp_unlock_pkt(fsp);
}
/**
* fc_fcp_cleanup() - Cleanup all FCP exchanges on a local port
* @lport: The local port to be cleaned up
*/
static void fc_fcp_cleanup(struct fc_lport *lport)
{
fc_fcp_cleanup_each_cmd(lport, -1, -1, FC_ERROR);
}
/**
* fc_fcp_timeout() - Handler for fcp_pkt timeouts
* @data: The FCP packet that has timed out
*
* If REC is supported then just issue it and return. The REC exchange will
* complete or time out and recovery can continue at that point. Otherwise,
* if the response has been received without all the data it has been
* ER_TIMEOUT since the response was received. If the response has not been
* received we see if data was received recently. If it has been then we
* continue waiting, otherwise, we abort the command.
*/
static void fc_fcp_timeout(unsigned long data)
{
struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)data;
struct fc_rport *rport = fsp->rport;
struct fc_rport_libfc_priv *rpriv = rport->dd_data;
if (fc_fcp_lock_pkt(fsp))
return;
if (fsp->cdb_cmd.fc_tm_flags)
goto unlock;
fsp->state |= FC_SRB_FCP_PROCESSING_TMO;
if (rpriv->flags & FC_RP_FLAGS_REC_SUPPORTED)
fc_fcp_rec(fsp);
else if (time_after_eq(fsp->last_pkt_time + (FC_SCSI_ER_TIMEOUT / 2),
jiffies))
fc_fcp_timer_set(fsp, FC_SCSI_ER_TIMEOUT);
else if (fsp->state & FC_SRB_RCV_STATUS)
fc_fcp_complete_locked(fsp);
else
fc_timeout_error(fsp);
fsp->state &= ~FC_SRB_FCP_PROCESSING_TMO;
unlock:
fc_fcp_unlock_pkt(fsp);
}
/**
* fc_fcp_rec() - Send a REC ELS request
* @fsp: The FCP packet to send the REC request on
*/
static void fc_fcp_rec(struct fc_fcp_pkt *fsp)
{
struct fc_lport *lport;
struct fc_frame *fp;
struct fc_rport *rport;
struct fc_rport_libfc_priv *rpriv;
lport = fsp->lp;
rport = fsp->rport;
rpriv = rport->dd_data;
if (!fsp->seq_ptr || rpriv->rp_state != RPORT_ST_READY) {
fsp->status_code = FC_HRD_ERROR;
fsp->io_status = 0;
fc_fcp_complete_locked(fsp);
return;
}
fp = fc_frame_alloc(lport, sizeof(struct fc_els_rec));
if (!fp)
goto retry;
fr_seq(fp) = fsp->seq_ptr;
fc_fill_fc_hdr(fp, FC_RCTL_ELS_REQ, rport->port_id,
fc_host_port_id(rpriv->local_port->host), FC_TYPE_ELS,
FC_FC_FIRST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
if (lport->tt.elsct_send(lport, rport->port_id, fp, ELS_REC,
fc_fcp_rec_resp, fsp,
jiffies_to_msecs(FC_SCSI_REC_TOV))) {
fc_fcp_pkt_hold(fsp); /* hold while REC outstanding */
return;
}
retry:
if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
fc_fcp_timer_set(fsp, FC_SCSI_REC_TOV);
else
fc_timeout_error(fsp);
}
/**
* fc_fcp_rec_resp() - Handler for REC ELS responses
* @seq: The sequence the response is on
* @fp: The response frame
* @arg: The FCP packet the response is on
*
* If the response is a reject then the scsi layer will handle
* the timeout. If the response is a LS_ACC then if the I/O was not completed
* set the timeout and return. If the I/O was completed then complete the
* exchange and tell the SCSI layer.
*/
static void fc_fcp_rec_resp(struct fc_seq *seq, struct fc_frame *fp, void *arg)
{
struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)arg;
struct fc_els_rec_acc *recp;
struct fc_els_ls_rjt *rjt;
u32 e_stat;
u8 opcode;
u32 offset;
enum dma_data_direction data_dir;
enum fc_rctl r_ctl;
struct fc_rport_libfc_priv *rpriv;
if (IS_ERR(fp)) {
fc_fcp_rec_error(fsp, fp);
return;
}
if (fc_fcp_lock_pkt(fsp))
goto out;
fsp->recov_retry = 0;
opcode = fc_frame_payload_op(fp);
if (opcode == ELS_LS_RJT) {
rjt = fc_frame_payload_get(fp, sizeof(*rjt));
switch (rjt->er_reason) {
default:
FC_FCP_DBG(fsp, "device %x unexpected REC reject "
"reason %d expl %d\n",
fsp->rport->port_id, rjt->er_reason,
rjt->er_explan);
/* fall through */
case ELS_RJT_UNSUP:
FC_FCP_DBG(fsp, "device does not support REC\n");
rpriv = fsp->rport->dd_data;
/*
* if we do not spport RECs or got some bogus
* reason then resetup timer so we check for
* making progress.
*/
rpriv->flags &= ~FC_RP_FLAGS_REC_SUPPORTED;
fc_fcp_timer_set(fsp, FC_SCSI_ER_TIMEOUT);
break;
case ELS_RJT_LOGIC:
case ELS_RJT_UNAB:
/*
* If no data transfer, the command frame got dropped
* so we just retry. If data was transferred, we
* lost the response but the target has no record,
* so we abort and retry.
*/
if (rjt->er_explan == ELS_EXPL_OXID_RXID &&
fsp->xfer_len == 0) {
fc_fcp_retry_cmd(fsp);
break;
}
fc_timeout_error(fsp);
break;
}
} else if (opcode == ELS_LS_ACC) {
if (fsp->state & FC_SRB_ABORTED)
goto unlock_out;
data_dir = fsp->cmd->sc_data_direction;
recp = fc_frame_payload_get(fp, sizeof(*recp));
offset = ntohl(recp->reca_fc4value);
e_stat = ntohl(recp->reca_e_stat);
if (e_stat & ESB_ST_COMPLETE) {
/*
* The exchange is complete.
*
* For output, we must've lost the response.
* For input, all data must've been sent.
* We lost may have lost the response
* (and a confirmation was requested) and maybe
* some data.
*
* If all data received, send SRR
* asking for response. If partial data received,
* or gaps, SRR requests data at start of gap.
* Recovery via SRR relies on in-order-delivery.
*/
if (data_dir == DMA_TO_DEVICE) {
r_ctl = FC_RCTL_DD_CMD_STATUS;
} else if (fsp->xfer_contig_end == offset) {
r_ctl = FC_RCTL_DD_CMD_STATUS;
} else {
offset = fsp->xfer_contig_end;
r_ctl = FC_RCTL_DD_SOL_DATA;
}
fc_fcp_srr(fsp, r_ctl, offset);
} else if (e_stat & ESB_ST_SEQ_INIT) {
/*
* The remote port has the initiative, so just
* keep waiting for it to complete.
*/
fc_fcp_timer_set(fsp, FC_SCSI_REC_TOV);
} else {
/*
* The exchange is incomplete, we have seq. initiative.
* Lost response with requested confirmation,
* lost confirmation, lost transfer ready or
* lost write data.
*
* For output, if not all data was received, ask
* for transfer ready to be repeated.
*
* If we received or sent all the data, send SRR to
* request response.
*
* If we lost a response, we may have lost some read
* data as well.
*/
r_ctl = FC_RCTL_DD_SOL_DATA;
if (data_dir == DMA_TO_DEVICE) {
r_ctl = FC_RCTL_DD_CMD_STATUS;
if (offset < fsp->data_len)
r_ctl = FC_RCTL_DD_DATA_DESC;
} else if (offset == fsp->xfer_contig_end) {
r_ctl = FC_RCTL_DD_CMD_STATUS;
} else if (fsp->xfer_contig_end < offset) {
offset = fsp->xfer_contig_end;
}
fc_fcp_srr(fsp, r_ctl, offset);
}
}
unlock_out:
fc_fcp_unlock_pkt(fsp);
out:
fc_fcp_pkt_release(fsp); /* drop hold for outstanding REC */
fc_frame_free(fp);
}
/**
* fc_fcp_rec_error() - Handler for REC errors
* @fsp: The FCP packet the error is on
* @fp: The REC frame
*/
static void fc_fcp_rec_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
{
int error = PTR_ERR(fp);
if (fc_fcp_lock_pkt(fsp))
goto out;
switch (error) {
case -FC_EX_CLOSED:
fc_fcp_retry_cmd(fsp);
break;
default:
FC_FCP_DBG(fsp, "REC %p fid %x error unexpected error %d\n",
fsp, fsp->rport->port_id, error);
fsp->status_code = FC_CMD_PLOGO;
/* fall through */
case -FC_EX_TIMEOUT:
/*
* Assume REC or LS_ACC was lost.
* The exchange manager will have aborted REC, so retry.
*/
FC_FCP_DBG(fsp, "REC fid %x error error %d retry %d/%d\n",
fsp->rport->port_id, error, fsp->recov_retry,
FC_MAX_RECOV_RETRY);
if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
fc_fcp_rec(fsp);
else
fc_timeout_error(fsp);
break;
}
fc_fcp_unlock_pkt(fsp);
out:
fc_fcp_pkt_release(fsp); /* drop hold for outstanding REC */
}
/**
* fc_timeout_error() - Handler for fcp_pkt timeouts
* @fsp: The FCP packt that has timed out
*/
static void fc_timeout_error(struct fc_fcp_pkt *fsp)
{
fsp->status_code = FC_CMD_TIME_OUT;
fsp->cdb_status = 0;
fsp->io_status = 0;
/*
* if this fails then we let the scsi command timer fire and
* scsi-ml escalate.
*/
fc_fcp_send_abort(fsp);
}
/**
* fc_fcp_srr() - Send a SRR request (Sequence Retransmission Request)
* @fsp: The FCP packet the SRR is to be sent on
* @r_ctl: The R_CTL field for the SRR request
* This is called after receiving status but insufficient data, or
* when expecting status but the request has timed out.
*/
static void fc_fcp_srr(struct fc_fcp_pkt *fsp, enum fc_rctl r_ctl, u32 offset)
{
struct fc_lport *lport = fsp->lp;
struct fc_rport *rport;
struct fc_rport_libfc_priv *rpriv;
struct fc_exch *ep = fc_seq_exch(fsp->seq_ptr);
struct fc_seq *seq;
struct fcp_srr *srr;
struct fc_frame *fp;
u8 cdb_op;
rport = fsp->rport;
rpriv = rport->dd_data;
cdb_op = fsp->cdb_cmd.fc_cdb[0];
if (!(rpriv->flags & FC_RP_FLAGS_RETRY) ||
rpriv->rp_state != RPORT_ST_READY)
goto retry; /* shouldn't happen */
fp = fc_frame_alloc(lport, sizeof(*srr));
if (!fp)
goto retry;
srr = fc_frame_payload_get(fp, sizeof(*srr));
memset(srr, 0, sizeof(*srr));
srr->srr_op = ELS_SRR;
srr->srr_ox_id = htons(ep->oxid);
srr->srr_rx_id = htons(ep->rxid);
srr->srr_r_ctl = r_ctl;
srr->srr_rel_off = htonl(offset);
fc_fill_fc_hdr(fp, FC_RCTL_ELS4_REQ, rport->port_id,
fc_host_port_id(rpriv->local_port->host), FC_TYPE_FCP,
FC_FC_FIRST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
seq = lport->tt.exch_seq_send(lport, fp, fc_fcp_srr_resp, NULL,
fsp, jiffies_to_msecs(FC_SCSI_REC_TOV));
if (!seq)
goto retry;
fsp->recov_seq = seq;
fsp->xfer_len = offset;
fsp->xfer_contig_end = offset;
fsp->state &= ~FC_SRB_RCV_STATUS;
fc_fcp_pkt_hold(fsp); /* hold for outstanding SRR */
return;
retry:
fc_fcp_retry_cmd(fsp);
}
/**
* fc_fcp_srr_resp() - Handler for SRR response
* @seq: The sequence the SRR is on
* @fp: The SRR frame
* @arg: The FCP packet the SRR is on
*/
static void fc_fcp_srr_resp(struct fc_seq *seq, struct fc_frame *fp, void *arg)
{
struct fc_fcp_pkt *fsp = arg;
struct fc_frame_header *fh;
if (IS_ERR(fp)) {
fc_fcp_srr_error(fsp, fp);
return;
}
if (fc_fcp_lock_pkt(fsp))
goto out;
fh = fc_frame_header_get(fp);
/*
* BUG? fc_fcp_srr_error calls exch_done which would release
* the ep. But if fc_fcp_srr_error had got -FC_EX_TIMEOUT,
* then fc_exch_timeout would be sending an abort. The exch_done
* call by fc_fcp_srr_error would prevent fc_exch.c from seeing
* an abort response though.
*/
if (fh->fh_type == FC_TYPE_BLS) {
fc_fcp_unlock_pkt(fsp);
return;
}
fsp->recov_seq = NULL;
switch (fc_frame_payload_op(fp)) {
case ELS_LS_ACC:
fsp->recov_retry = 0;
fc_fcp_timer_set(fsp, FC_SCSI_REC_TOV);
break;
case ELS_LS_RJT:
default:
fc_timeout_error(fsp);
break;
}
fc_fcp_unlock_pkt(fsp);
fsp->lp->tt.exch_done(seq);
out:
fc_frame_free(fp);
fc_fcp_pkt_release(fsp); /* drop hold for outstanding SRR */
}
/**
* fc_fcp_srr_error() - Handler for SRR errors
* @fsp: The FCP packet that the SRR error is on
* @fp: The SRR frame
*/
static void fc_fcp_srr_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
{
if (fc_fcp_lock_pkt(fsp))
goto out;
fsp->lp->tt.exch_done(fsp->recov_seq);
fsp->recov_seq = NULL;
switch (PTR_ERR(fp)) {
case -FC_EX_TIMEOUT:
if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
fc_fcp_rec(fsp);
else
fc_timeout_error(fsp);
break;
case -FC_EX_CLOSED: /* e.g., link failure */
/* fall through */
default:
fc_fcp_retry_cmd(fsp);
break;
}
fc_fcp_unlock_pkt(fsp);
out:
fc_fcp_pkt_release(fsp); /* drop hold for outstanding SRR */
}
/**
* fc_fcp_lport_queue_ready() - Determine if the lport and it's queue is ready
* @lport: The local port to be checked
*/
static inline int fc_fcp_lport_queue_ready(struct fc_lport *lport)
{
/* lock ? */
return (lport->state == LPORT_ST_READY) &&
lport->link_up && !lport->qfull;
}
/**
* fc_queuecommand() - The queuecommand function of the SCSI template
* @cmd: The scsi_cmnd to be executed
* @done: The callback function to be called when the scsi_cmnd is complete
*
* This is the i/o strategy routine, called by the SCSI layer. This routine
* is called with the host_lock held.
*/
int fc_queuecommand(struct scsi_cmnd *sc_cmd, void (*done)(struct scsi_cmnd *))
{
struct fc_lport *lport;
struct fc_rport *rport = starget_to_rport(scsi_target(sc_cmd->device));
struct fc_fcp_pkt *fsp;
struct fc_rport_libfc_priv *rpriv;
int rval;
int rc = 0;
struct fcoe_dev_stats *stats;
lport = shost_priv(sc_cmd->device->host);
rval = fc_remote_port_chkready(rport);
if (rval) {
sc_cmd->result = rval;
done(sc_cmd);
goto out;
}
if (!*(struct fc_remote_port **)rport->dd_data) {
/*
* rport is transitioning from blocked/deleted to
* online
*/
sc_cmd->result = DID_IMM_RETRY << 16;
done(sc_cmd);
goto out;
}
rpriv = rport->dd_data;
if (!fc_fcp_lport_queue_ready(lport)) {
rc = SCSI_MLQUEUE_HOST_BUSY;
goto out;
}
fsp = fc_fcp_pkt_alloc(lport, GFP_ATOMIC);
if (fsp == NULL) {
rc = SCSI_MLQUEUE_HOST_BUSY;
goto out;
}
/*
* build the libfc request pkt
*/
fsp->cmd = sc_cmd; /* save the cmd */
fsp->lp = lport; /* save the softc ptr */
fsp->rport = rport; /* set the remote port ptr */
fsp->xfer_ddp = FC_XID_UNKNOWN;
sc_cmd->scsi_done = done;
/*
* set up the transfer length
*/
fsp->data_len = scsi_bufflen(sc_cmd);
fsp->xfer_len = 0;
/*
* setup the data direction
*/
stats = fc_lport_get_stats(lport);
if (sc_cmd->sc_data_direction == DMA_FROM_DEVICE) {
fsp->req_flags = FC_SRB_READ;
stats->InputRequests++;
stats->InputMegabytes = fsp->data_len;
} else if (sc_cmd->sc_data_direction == DMA_TO_DEVICE) {
fsp->req_flags = FC_SRB_WRITE;
stats->OutputRequests++;
stats->OutputMegabytes = fsp->data_len;
} else {
fsp->req_flags = 0;
stats->ControlRequests++;
}
fsp->tgt_flags = rpriv->flags;
init_timer(&fsp->timer);
fsp->timer.data = (unsigned long)fsp;
/*
* send it to the lower layer
* if we get -1 return then put the request in the pending
* queue.
*/
rval = fc_fcp_pkt_send(lport, fsp);
if (rval != 0) {
fsp->state = FC_SRB_FREE;
fc_fcp_pkt_release(fsp);
rc = SCSI_MLQUEUE_HOST_BUSY;
}
out:
return rc;
}
EXPORT_SYMBOL(fc_queuecommand);
/**
* fc_io_compl() - Handle responses for completed commands
* @fsp: The FCP packet that is complete
*
* Translates fcp_pkt errors to a Linux SCSI errors.
* The fcp packet lock must be held when calling.
*/
static void fc_io_compl(struct fc_fcp_pkt *fsp)
{
struct fc_fcp_internal *si;
struct scsi_cmnd *sc_cmd;
struct fc_lport *lport;
unsigned long flags;
/* release outstanding ddp context */
fc_fcp_ddp_done(fsp);
fsp->state |= FC_SRB_COMPL;
if (!(fsp->state & FC_SRB_FCP_PROCESSING_TMO)) {
spin_unlock_bh(&fsp->scsi_pkt_lock);
del_timer_sync(&fsp->timer);
spin_lock_bh(&fsp->scsi_pkt_lock);
}
lport = fsp->lp;
si = fc_get_scsi_internal(lport);
spin_lock_irqsave(lport->host->host_lock, flags);
if (!fsp->cmd) {
spin_unlock_irqrestore(lport->host->host_lock, flags);
return;
}
/*
* if a command timed out while we had to try and throttle IO
* and it is now getting cleaned up, then we are about to
* try again so clear the throttled flag incase we get more
* time outs.
*/
if (si->throttled && fsp->state & FC_SRB_NOMEM)
si->throttled = 0;
sc_cmd = fsp->cmd;
fsp->cmd = NULL;
if (!sc_cmd->SCp.ptr) {
spin_unlock_irqrestore(lport->host->host_lock, flags);
return;
}
CMD_SCSI_STATUS(sc_cmd) = fsp->cdb_status;
switch (fsp->status_code) {
case FC_COMPLETE:
if (fsp->cdb_status == 0) {
/*
* good I/O status
*/
sc_cmd->result = DID_OK << 16;
if (fsp->scsi_resid)
CMD_RESID_LEN(sc_cmd) = fsp->scsi_resid;
} else {
/*
* transport level I/O was ok but scsi
* has non zero status
*/
sc_cmd->result = (DID_OK << 16) | fsp->cdb_status;
}
break;
case FC_ERROR:
sc_cmd->result = DID_ERROR << 16;
break;
case FC_DATA_UNDRUN:
if ((fsp->cdb_status == 0) && !(fsp->req_flags & FC_SRB_READ)) {
/*
* scsi status is good but transport level
* underrun.
*/
sc_cmd->result = (fsp->state & FC_SRB_RCV_STATUS ?
DID_OK : DID_ERROR) << 16;
} else {
/*
* scsi got underrun, this is an error
*/
CMD_RESID_LEN(sc_cmd) = fsp->scsi_resid;
sc_cmd->result = (DID_ERROR << 16) | fsp->cdb_status;
}
break;
case FC_DATA_OVRRUN:
/*
* overrun is an error
*/
sc_cmd->result = (DID_ERROR << 16) | fsp->cdb_status;
break;
case FC_CMD_ABORTED:
sc_cmd->result = (DID_ERROR << 16) | fsp->io_status;
break;
case FC_CMD_TIME_OUT:
sc_cmd->result = (DID_BUS_BUSY << 16) | fsp->io_status;
break;
case FC_CMD_RESET:
sc_cmd->result = (DID_RESET << 16);
break;
case FC_HRD_ERROR:
sc_cmd->result = (DID_NO_CONNECT << 16);
break;
default:
sc_cmd->result = (DID_ERROR << 16);
break;
}
list_del(&fsp->list);
sc_cmd->SCp.ptr = NULL;
sc_cmd->scsi_done(sc_cmd);
spin_unlock_irqrestore(lport->host->host_lock, flags);
/* release ref from initial allocation in queue command */
fc_fcp_pkt_release(fsp);
}
/**
* fc_eh_abort() - Abort a command
* @sc_cmd: The SCSI command to abort
*
* From SCSI host template.
* Send an ABTS to the target device and wait for the response.
*/
int fc_eh_abort(struct scsi_cmnd *sc_cmd)
{
struct fc_fcp_pkt *fsp;
struct fc_lport *lport;
int rc = FAILED;
unsigned long flags;
lport = shost_priv(sc_cmd->device->host);
if (lport->state != LPORT_ST_READY)
return rc;
else if (!lport->link_up)
return rc;
spin_lock_irqsave(lport->host->host_lock, flags);
fsp = CMD_SP(sc_cmd);
if (!fsp) {
/* command completed while scsi eh was setting up */
spin_unlock_irqrestore(lport->host->host_lock, flags);
return SUCCESS;
}
/* grab a ref so the fsp and sc_cmd cannot be relased from under us */
fc_fcp_pkt_hold(fsp);
spin_unlock_irqrestore(lport->host->host_lock, flags);
if (fc_fcp_lock_pkt(fsp)) {
/* completed while we were waiting for timer to be deleted */
rc = SUCCESS;
goto release_pkt;
}
rc = fc_fcp_pkt_abort(fsp);
fc_fcp_unlock_pkt(fsp);
release_pkt:
fc_fcp_pkt_release(fsp);
return rc;
}
EXPORT_SYMBOL(fc_eh_abort);
/**
* fc_eh_device_reset() - Reset a single LUN
* @sc_cmd: The SCSI command which identifies the device whose
* LUN is to be reset
*
* Set from SCSI host template.
*/
int fc_eh_device_reset(struct scsi_cmnd *sc_cmd)
{
struct fc_lport *lport;
struct fc_fcp_pkt *fsp;
struct fc_rport *rport = starget_to_rport(scsi_target(sc_cmd->device));
int rc = FAILED;
int rval;
rval = fc_remote_port_chkready(rport);
if (rval)
goto out;
lport = shost_priv(sc_cmd->device->host);
if (lport->state != LPORT_ST_READY)
return rc;
FC_SCSI_DBG(lport, "Resetting rport (%6x)\n", rport->port_id);
fsp = fc_fcp_pkt_alloc(lport, GFP_NOIO);
if (fsp == NULL) {
printk(KERN_WARNING "libfc: could not allocate scsi_pkt\n");
sc_cmd->result = DID_NO_CONNECT << 16;
goto out;
}
/*
* Build the libfc request pkt. Do not set the scsi cmnd, because
* the sc passed in is not setup for execution like when sent
* through the queuecommand callout.
*/
fsp->lp = lport; /* save the softc ptr */
fsp->rport = rport; /* set the remote port ptr */
/*
* flush outstanding commands
*/
rc = fc_lun_reset(lport, fsp, scmd_id(sc_cmd), sc_cmd->device->lun);
fsp->state = FC_SRB_FREE;
fc_fcp_pkt_release(fsp);
out:
return rc;
}
EXPORT_SYMBOL(fc_eh_device_reset);
/**
* fc_eh_host_reset() - Reset a Scsi_Host.
* @sc_cmd: The SCSI command that identifies the SCSI host to be reset
*/
int fc_eh_host_reset(struct scsi_cmnd *sc_cmd)
{
struct Scsi_Host *shost = sc_cmd->device->host;
struct fc_lport *lport = shost_priv(shost);
unsigned long wait_tmo;
FC_SCSI_DBG(lport, "Resetting host\n");
lport->tt.lport_reset(lport);
wait_tmo = jiffies + FC_HOST_RESET_TIMEOUT;
while (!fc_fcp_lport_queue_ready(lport) && time_before(jiffies,
wait_tmo))
msleep(1000);
if (fc_fcp_lport_queue_ready(lport)) {
shost_printk(KERN_INFO, shost, "libfc: Host reset succeeded "
"on port (%6x)\n", fc_host_port_id(lport->host));
return SUCCESS;
} else {
shost_printk(KERN_INFO, shost, "libfc: Host reset failed, "
"port (%6x) is not ready.\n",
fc_host_port_id(lport->host));
return FAILED;
}
}
EXPORT_SYMBOL(fc_eh_host_reset);
/**
* fc_slave_alloc() - Configure the queue depth of a Scsi_Host
* @sdev: The SCSI device that identifies the SCSI host
*
* Configures queue depth based on host's cmd_per_len. If not set
* then we use the libfc default.
*/
int fc_slave_alloc(struct scsi_device *sdev)
{
struct fc_rport *rport = starget_to_rport(scsi_target(sdev));
if (!rport || fc_remote_port_chkready(rport))
return -ENXIO;
if (sdev->tagged_supported)
scsi_activate_tcq(sdev, FC_FCP_DFLT_QUEUE_DEPTH);
else
scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev),
FC_FCP_DFLT_QUEUE_DEPTH);
return 0;
}
EXPORT_SYMBOL(fc_slave_alloc);
/**
* fc_change_queue_depth() - Change a device's queue depth
* @sdev: The SCSI device whose queue depth is to change
* @qdepth: The new queue depth
* @reason: The resason for the change
*/
int fc_change_queue_depth(struct scsi_device *sdev, int qdepth, int reason)
{
switch (reason) {
case SCSI_QDEPTH_DEFAULT:
scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), qdepth);
break;
case SCSI_QDEPTH_QFULL:
scsi_track_queue_full(sdev, qdepth);
break;
case SCSI_QDEPTH_RAMP_UP:
scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), qdepth);
break;
default:
return -EOPNOTSUPP;
}
return sdev->queue_depth;
}
EXPORT_SYMBOL(fc_change_queue_depth);
/**
* fc_change_queue_type() - Change a device's queue type
* @sdev: The SCSI device whose queue depth is to change
* @tag_type: Identifier for queue type
*/
int fc_change_queue_type(struct scsi_device *sdev, int tag_type)
{
if (sdev->tagged_supported) {
scsi_set_tag_type(sdev, tag_type);
if (tag_type)
scsi_activate_tcq(sdev, sdev->queue_depth);
else
scsi_deactivate_tcq(sdev, sdev->queue_depth);
} else
tag_type = 0;
return tag_type;
}
EXPORT_SYMBOL(fc_change_queue_type);
/**
* fc_fcp_destory() - Tear down the FCP layer for a given local port
* @lport: The local port that no longer needs the FCP layer
*/
void fc_fcp_destroy(struct fc_lport *lport)
{
struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
if (!list_empty(&si->scsi_pkt_queue))
printk(KERN_ERR "libfc: Leaked SCSI packets when destroying "
"port (%6x)\n", fc_host_port_id(lport->host));
mempool_destroy(si->scsi_pkt_pool);
kfree(si);
lport->scsi_priv = NULL;
}
EXPORT_SYMBOL(fc_fcp_destroy);
int fc_setup_fcp()
{
int rc = 0;
scsi_pkt_cachep = kmem_cache_create("libfc_fcp_pkt",
sizeof(struct fc_fcp_pkt),
0, SLAB_HWCACHE_ALIGN, NULL);
if (!scsi_pkt_cachep) {
printk(KERN_ERR "libfc: Unable to allocate SRB cache, "
"module load failed!");
rc = -ENOMEM;
}
return rc;
}
void fc_destroy_fcp()
{
if (scsi_pkt_cachep)
kmem_cache_destroy(scsi_pkt_cachep);
}
/**
* fc_fcp_init() - Initialize the FCP layer for a local port
* @lport: The local port to initialize the exchange layer for
*/
int fc_fcp_init(struct fc_lport *lport)
{
int rc;
struct fc_fcp_internal *si;
if (!lport->tt.fcp_cmd_send)
lport->tt.fcp_cmd_send = fc_fcp_cmd_send;
if (!lport->tt.fcp_cleanup)
lport->tt.fcp_cleanup = fc_fcp_cleanup;
if (!lport->tt.fcp_abort_io)
lport->tt.fcp_abort_io = fc_fcp_abort_io;
si = kzalloc(sizeof(struct fc_fcp_internal), GFP_KERNEL);
if (!si)
return -ENOMEM;
lport->scsi_priv = si;
INIT_LIST_HEAD(&si->scsi_pkt_queue);
si->scsi_pkt_pool = mempool_create_slab_pool(2, scsi_pkt_cachep);
if (!si->scsi_pkt_pool) {
rc = -ENOMEM;
goto free_internal;
}
return 0;
free_internal:
kfree(si);
return rc;
}
EXPORT_SYMBOL(fc_fcp_init);