linux/drivers/s390/scsi/zfcp_qdio.c
Linus Torvalds fb5131e188 Merge branch 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6
* 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6: (65 commits)
  [S390] prevent unneccesary loops_per_jiffy recalculation
  [S390] cpuinfo: use get_online_cpus() instead of preempt_disable()
  [S390] smp: remove cpu hotplug messages
  [S390] mutex: enable spinning mutex on s390
  [S390] mutex: Introduce arch_mutex_cpu_relax()
  [S390] cio: fix ccwgroup unregistration race condition
  [S390] perf: add DWARF register lookup for s390
  [S390] cleanup ftrace backend functions
  [S390] ptrace cleanup
  [S390] smp/idle: call init_idle() before starting a new cpu
  [S390] smp: delay idle task creation
  [S390] dasd: Correct retry counter for terminated I/O.
  [S390] dasd: Add support for raw ECKD access.
  [S390] dasd: Prevent deadlock during suspend/resume.
  [S390] dasd: Improve handling of stolen DASD reservation
  [S390] dasd: do path verification for paths added at runtime
  [S390] dasd: add High Performance FICON multitrack support
  [S390] cio: reduce memory consumption of itcw structures
  [S390] nmi: enable machine checks early
  [S390] qeth: buffer count imbalance
  ...
2011-01-07 14:50:50 -08:00

472 lines
12 KiB
C

/*
* zfcp device driver
*
* Setup and helper functions to access QDIO.
*
* Copyright IBM Corporation 2002, 2010
*/
#define KMSG_COMPONENT "zfcp"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
#include <linux/slab.h>
#include "zfcp_ext.h"
#include "zfcp_qdio.h"
#define QBUFF_PER_PAGE (PAGE_SIZE / sizeof(struct qdio_buffer))
static int zfcp_qdio_buffers_enqueue(struct qdio_buffer **sbal)
{
int pos;
for (pos = 0; pos < QDIO_MAX_BUFFERS_PER_Q; pos += QBUFF_PER_PAGE) {
sbal[pos] = (struct qdio_buffer *) get_zeroed_page(GFP_KERNEL);
if (!sbal[pos])
return -ENOMEM;
}
for (pos = 0; pos < QDIO_MAX_BUFFERS_PER_Q; pos++)
if (pos % QBUFF_PER_PAGE)
sbal[pos] = sbal[pos - 1] + 1;
return 0;
}
static void zfcp_qdio_handler_error(struct zfcp_qdio *qdio, char *id,
unsigned int qdio_err)
{
struct zfcp_adapter *adapter = qdio->adapter;
dev_warn(&adapter->ccw_device->dev, "A QDIO problem occurred\n");
if (qdio_err & QDIO_ERROR_SLSB_STATE)
zfcp_qdio_siosl(adapter);
zfcp_erp_adapter_reopen(adapter,
ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED |
ZFCP_STATUS_COMMON_ERP_FAILED, id);
}
static void zfcp_qdio_zero_sbals(struct qdio_buffer *sbal[], int first, int cnt)
{
int i, sbal_idx;
for (i = first; i < first + cnt; i++) {
sbal_idx = i % QDIO_MAX_BUFFERS_PER_Q;
memset(sbal[sbal_idx], 0, sizeof(struct qdio_buffer));
}
}
/* this needs to be called prior to updating the queue fill level */
static inline void zfcp_qdio_account(struct zfcp_qdio *qdio)
{
unsigned long long now, span;
int used;
now = get_clock_monotonic();
span = (now - qdio->req_q_time) >> 12;
used = QDIO_MAX_BUFFERS_PER_Q - atomic_read(&qdio->req_q_free);
qdio->req_q_util += used * span;
qdio->req_q_time = now;
}
static void zfcp_qdio_int_req(struct ccw_device *cdev, unsigned int qdio_err,
int queue_no, int idx, int count,
unsigned long parm)
{
struct zfcp_qdio *qdio = (struct zfcp_qdio *) parm;
if (unlikely(qdio_err)) {
zfcp_qdio_handler_error(qdio, "qdireq1", qdio_err);
return;
}
/* cleanup all SBALs being program-owned now */
zfcp_qdio_zero_sbals(qdio->req_q, idx, count);
spin_lock_irq(&qdio->stat_lock);
zfcp_qdio_account(qdio);
spin_unlock_irq(&qdio->stat_lock);
atomic_add(count, &qdio->req_q_free);
wake_up(&qdio->req_q_wq);
}
static void zfcp_qdio_int_resp(struct ccw_device *cdev, unsigned int qdio_err,
int queue_no, int idx, int count,
unsigned long parm)
{
struct zfcp_qdio *qdio = (struct zfcp_qdio *) parm;
int sbal_idx, sbal_no;
if (unlikely(qdio_err)) {
zfcp_qdio_handler_error(qdio, "qdires1", qdio_err);
return;
}
/*
* go through all SBALs from input queue currently
* returned by QDIO layer
*/
for (sbal_no = 0; sbal_no < count; sbal_no++) {
sbal_idx = (idx + sbal_no) % QDIO_MAX_BUFFERS_PER_Q;
/* go through all SBALEs of SBAL */
zfcp_fsf_reqid_check(qdio, sbal_idx);
}
/*
* put SBALs back to response queue
*/
if (do_QDIO(cdev, QDIO_FLAG_SYNC_INPUT, 0, idx, count))
zfcp_erp_adapter_reopen(qdio->adapter, 0, "qdires2");
}
static struct qdio_buffer_element *
zfcp_qdio_sbal_chain(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
{
struct qdio_buffer_element *sbale;
/* set last entry flag in current SBALE of current SBAL */
sbale = zfcp_qdio_sbale_curr(qdio, q_req);
sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
/* don't exceed last allowed SBAL */
if (q_req->sbal_last == q_req->sbal_limit)
return NULL;
/* set chaining flag in first SBALE of current SBAL */
sbale = zfcp_qdio_sbale_req(qdio, q_req);
sbale->flags |= SBAL_FLAGS0_MORE_SBALS;
/* calculate index of next SBAL */
q_req->sbal_last++;
q_req->sbal_last %= QDIO_MAX_BUFFERS_PER_Q;
/* keep this requests number of SBALs up-to-date */
q_req->sbal_number++;
BUG_ON(q_req->sbal_number > ZFCP_QDIO_MAX_SBALS_PER_REQ);
/* start at first SBALE of new SBAL */
q_req->sbale_curr = 0;
/* set storage-block type for new SBAL */
sbale = zfcp_qdio_sbale_curr(qdio, q_req);
sbale->flags |= q_req->sbtype;
return sbale;
}
static struct qdio_buffer_element *
zfcp_qdio_sbale_next(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
{
if (q_req->sbale_curr == ZFCP_QDIO_LAST_SBALE_PER_SBAL)
return zfcp_qdio_sbal_chain(qdio, q_req);
q_req->sbale_curr++;
return zfcp_qdio_sbale_curr(qdio, q_req);
}
/**
* zfcp_qdio_sbals_from_sg - fill SBALs from scatter-gather list
* @qdio: pointer to struct zfcp_qdio
* @q_req: pointer to struct zfcp_qdio_req
* @sg: scatter-gather list
* @max_sbals: upper bound for number of SBALs to be used
* Returns: number of bytes, or error (negativ)
*/
int zfcp_qdio_sbals_from_sg(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
struct scatterlist *sg)
{
struct qdio_buffer_element *sbale;
int bytes = 0;
/* set storage-block type for this request */
sbale = zfcp_qdio_sbale_req(qdio, q_req);
sbale->flags |= q_req->sbtype;
for (; sg; sg = sg_next(sg)) {
sbale = zfcp_qdio_sbale_next(qdio, q_req);
if (!sbale) {
atomic_inc(&qdio->req_q_full);
zfcp_qdio_zero_sbals(qdio->req_q, q_req->sbal_first,
q_req->sbal_number);
return -EINVAL;
}
sbale->addr = sg_virt(sg);
sbale->length = sg->length;
bytes += sg->length;
}
return bytes;
}
static int zfcp_qdio_sbal_check(struct zfcp_qdio *qdio)
{
spin_lock_irq(&qdio->req_q_lock);
if (atomic_read(&qdio->req_q_free) ||
!(atomic_read(&qdio->adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP))
return 1;
spin_unlock_irq(&qdio->req_q_lock);
return 0;
}
/**
* zfcp_qdio_sbal_get - get free sbal in request queue, wait if necessary
* @qdio: pointer to struct zfcp_qdio
*
* The req_q_lock must be held by the caller of this function, and
* this function may only be called from process context; it will
* sleep when waiting for a free sbal.
*
* Returns: 0 on success, -EIO if there is no free sbal after waiting.
*/
int zfcp_qdio_sbal_get(struct zfcp_qdio *qdio)
{
long ret;
spin_unlock_irq(&qdio->req_q_lock);
ret = wait_event_interruptible_timeout(qdio->req_q_wq,
zfcp_qdio_sbal_check(qdio), 5 * HZ);
if (!(atomic_read(&qdio->adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP))
return -EIO;
if (ret > 0)
return 0;
if (!ret) {
atomic_inc(&qdio->req_q_full);
/* assume hanging outbound queue, try queue recovery */
zfcp_erp_adapter_reopen(qdio->adapter, 0, "qdsbg_1");
}
spin_lock_irq(&qdio->req_q_lock);
return -EIO;
}
/**
* zfcp_qdio_send - set PCI flag in first SBALE and send req to QDIO
* @qdio: pointer to struct zfcp_qdio
* @q_req: pointer to struct zfcp_qdio_req
* Returns: 0 on success, error otherwise
*/
int zfcp_qdio_send(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
{
int retval;
u8 sbal_number = q_req->sbal_number;
spin_lock(&qdio->stat_lock);
zfcp_qdio_account(qdio);
spin_unlock(&qdio->stat_lock);
retval = do_QDIO(qdio->adapter->ccw_device, QDIO_FLAG_SYNC_OUTPUT, 0,
q_req->sbal_first, sbal_number);
if (unlikely(retval)) {
zfcp_qdio_zero_sbals(qdio->req_q, q_req->sbal_first,
sbal_number);
return retval;
}
/* account for transferred buffers */
atomic_sub(sbal_number, &qdio->req_q_free);
qdio->req_q_idx += sbal_number;
qdio->req_q_idx %= QDIO_MAX_BUFFERS_PER_Q;
return 0;
}
static void zfcp_qdio_setup_init_data(struct qdio_initialize *id,
struct zfcp_qdio *qdio)
{
memset(id, 0, sizeof(*id));
id->cdev = qdio->adapter->ccw_device;
id->q_format = QDIO_ZFCP_QFMT;
memcpy(id->adapter_name, dev_name(&id->cdev->dev), 8);
ASCEBC(id->adapter_name, 8);
id->qib_rflags = QIB_RFLAGS_ENABLE_DATA_DIV;
id->no_input_qs = 1;
id->no_output_qs = 1;
id->input_handler = zfcp_qdio_int_resp;
id->output_handler = zfcp_qdio_int_req;
id->int_parm = (unsigned long) qdio;
id->input_sbal_addr_array = (void **) (qdio->res_q);
id->output_sbal_addr_array = (void **) (qdio->req_q);
id->scan_threshold =
QDIO_MAX_BUFFERS_PER_Q - ZFCP_QDIO_MAX_SBALS_PER_REQ * 2;
}
/**
* zfcp_qdio_allocate - allocate queue memory and initialize QDIO data
* @adapter: pointer to struct zfcp_adapter
* Returns: -ENOMEM on memory allocation error or return value from
* qdio_allocate
*/
static int zfcp_qdio_allocate(struct zfcp_qdio *qdio)
{
struct qdio_initialize init_data;
if (zfcp_qdio_buffers_enqueue(qdio->req_q) ||
zfcp_qdio_buffers_enqueue(qdio->res_q))
return -ENOMEM;
zfcp_qdio_setup_init_data(&init_data, qdio);
init_waitqueue_head(&qdio->req_q_wq);
return qdio_allocate(&init_data);
}
/**
* zfcp_close_qdio - close qdio queues for an adapter
* @qdio: pointer to structure zfcp_qdio
*/
void zfcp_qdio_close(struct zfcp_qdio *qdio)
{
struct zfcp_adapter *adapter = qdio->adapter;
int idx, count;
if (!(atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP))
return;
/* clear QDIOUP flag, thus do_QDIO is not called during qdio_shutdown */
spin_lock_irq(&qdio->req_q_lock);
atomic_clear_mask(ZFCP_STATUS_ADAPTER_QDIOUP, &adapter->status);
spin_unlock_irq(&qdio->req_q_lock);
wake_up(&qdio->req_q_wq);
qdio_shutdown(adapter->ccw_device, QDIO_FLAG_CLEANUP_USING_CLEAR);
/* cleanup used outbound sbals */
count = atomic_read(&qdio->req_q_free);
if (count < QDIO_MAX_BUFFERS_PER_Q) {
idx = (qdio->req_q_idx + count) % QDIO_MAX_BUFFERS_PER_Q;
count = QDIO_MAX_BUFFERS_PER_Q - count;
zfcp_qdio_zero_sbals(qdio->req_q, idx, count);
}
qdio->req_q_idx = 0;
atomic_set(&qdio->req_q_free, 0);
}
/**
* zfcp_qdio_open - prepare and initialize response queue
* @qdio: pointer to struct zfcp_qdio
* Returns: 0 on success, otherwise -EIO
*/
int zfcp_qdio_open(struct zfcp_qdio *qdio)
{
struct qdio_buffer_element *sbale;
struct qdio_initialize init_data;
struct zfcp_adapter *adapter = qdio->adapter;
struct ccw_device *cdev = adapter->ccw_device;
struct qdio_ssqd_desc ssqd;
int cc;
if (atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP)
return -EIO;
atomic_clear_mask(ZFCP_STATUS_ADAPTER_SIOSL_ISSUED,
&qdio->adapter->status);
zfcp_qdio_setup_init_data(&init_data, qdio);
if (qdio_establish(&init_data))
goto failed_establish;
if (qdio_get_ssqd_desc(init_data.cdev, &ssqd))
goto failed_qdio;
if (ssqd.qdioac2 & CHSC_AC2_DATA_DIV_ENABLED)
atomic_set_mask(ZFCP_STATUS_ADAPTER_DATA_DIV_ENABLED,
&qdio->adapter->status);
if (qdio_activate(cdev))
goto failed_qdio;
for (cc = 0; cc < QDIO_MAX_BUFFERS_PER_Q; cc++) {
sbale = &(qdio->res_q[cc]->element[0]);
sbale->length = 0;
sbale->flags = SBAL_FLAGS_LAST_ENTRY;
sbale->addr = NULL;
}
if (do_QDIO(cdev, QDIO_FLAG_SYNC_INPUT, 0, 0, QDIO_MAX_BUFFERS_PER_Q))
goto failed_qdio;
/* set index of first avalable SBALS / number of available SBALS */
qdio->req_q_idx = 0;
atomic_set(&qdio->req_q_free, QDIO_MAX_BUFFERS_PER_Q);
atomic_set_mask(ZFCP_STATUS_ADAPTER_QDIOUP, &qdio->adapter->status);
return 0;
failed_qdio:
qdio_shutdown(cdev, QDIO_FLAG_CLEANUP_USING_CLEAR);
failed_establish:
dev_err(&cdev->dev,
"Setting up the QDIO connection to the FCP adapter failed\n");
return -EIO;
}
void zfcp_qdio_destroy(struct zfcp_qdio *qdio)
{
int p;
if (!qdio)
return;
if (qdio->adapter->ccw_device)
qdio_free(qdio->adapter->ccw_device);
for (p = 0; p < QDIO_MAX_BUFFERS_PER_Q; p += QBUFF_PER_PAGE) {
free_page((unsigned long) qdio->req_q[p]);
free_page((unsigned long) qdio->res_q[p]);
}
kfree(qdio);
}
int zfcp_qdio_setup(struct zfcp_adapter *adapter)
{
struct zfcp_qdio *qdio;
qdio = kzalloc(sizeof(struct zfcp_qdio), GFP_KERNEL);
if (!qdio)
return -ENOMEM;
qdio->adapter = adapter;
if (zfcp_qdio_allocate(qdio)) {
zfcp_qdio_destroy(qdio);
return -ENOMEM;
}
spin_lock_init(&qdio->req_q_lock);
spin_lock_init(&qdio->stat_lock);
adapter->qdio = qdio;
return 0;
}
/**
* zfcp_qdio_siosl - Trigger logging in FCP channel
* @adapter: The zfcp_adapter where to trigger logging
*
* Call the cio siosl function to trigger hardware logging. This
* wrapper function sets a flag to ensure hardware logging is only
* triggered once before going through qdio shutdown.
*
* The triggers are always run from qdio tasklet context, so no
* additional synchronization is necessary.
*/
void zfcp_qdio_siosl(struct zfcp_adapter *adapter)
{
int rc;
if (atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_SIOSL_ISSUED)
return;
rc = ccw_device_siosl(adapter->ccw_device);
if (!rc)
atomic_set_mask(ZFCP_STATUS_ADAPTER_SIOSL_ISSUED,
&adapter->status);
}