/*
* zfcp device driver
*
* Setup and helper functions to access QDIO.
*
* Copyright IBM Corporation 2002, 2008
*/
#define KMSG_COMPONENT "zfcp"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
#include "zfcp_ext.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 struct qdio_buffer_element *
zfcp_qdio_sbale(struct zfcp_qdio_queue *q, int sbal_idx, int sbale_idx)
{
return &q->sbal[sbal_idx]->element[sbale_idx];
}
/**
* zfcp_qdio_free - free memory used by request- and resposne queue
* @adapter: pointer to the zfcp_adapter structure
*/
void zfcp_qdio_free(struct zfcp_adapter *adapter)
{
struct qdio_buffer **sbal_req, **sbal_resp;
int p;
if (adapter->ccw_device)
qdio_free(adapter->ccw_device);
sbal_req = adapter->req_q.sbal;
sbal_resp = adapter->resp_q.sbal;
for (p = 0; p < QDIO_MAX_BUFFERS_PER_Q; p += QBUFF_PER_PAGE) {
free_page((unsigned long) sbal_req[p]);
free_page((unsigned long) sbal_resp[p]);
}
}
static void zfcp_qdio_handler_error(struct zfcp_adapter *adapter, char *id)
{
dev_warn(&adapter->ccw_device->dev, "A QDIO problem occurred\n");
zfcp_erp_adapter_reopen(adapter,
ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED |
ZFCP_STATUS_COMMON_ERP_FAILED, id, NULL);
}
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 void zfcp_qdio_account(struct zfcp_adapter *adapter)
{
ktime_t now;
s64 span;
int free, used;
spin_lock(&adapter->qdio_stat_lock);
now = ktime_get();
span = ktime_us_delta(now, adapter->req_q_time);
free = max(0, atomic_read(&adapter->req_q.count));
used = QDIO_MAX_BUFFERS_PER_Q - free;
adapter->req_q_util += used * span;
adapter->req_q_time = now;
spin_unlock(&adapter->qdio_stat_lock);
}
static void zfcp_qdio_int_req(struct ccw_device *cdev, unsigned int qdio_err,
int queue_no, int first, int count,
unsigned long parm)
{
struct zfcp_adapter *adapter = (struct zfcp_adapter *) parm;
struct zfcp_qdio_queue *queue = &adapter->req_q;
if (unlikely(qdio_err)) {
zfcp_hba_dbf_event_qdio(adapter, qdio_err, first, count);
zfcp_qdio_handler_error(adapter, "qdireq1");
return;
}
/* cleanup all SBALs being program-owned now */
zfcp_qdio_zero_sbals(queue->sbal, first, count);
zfcp_qdio_account(adapter);
atomic_add(count, &queue->count);
wake_up(&adapter->request_wq);
}
static void zfcp_qdio_reqid_check(struct zfcp_adapter *adapter,
unsigned long req_id, int sbal_idx)
{
struct zfcp_fsf_req *fsf_req;
unsigned long flags;
spin_lock_irqsave(&adapter->req_list_lock, flags);
fsf_req = zfcp_reqlist_find(adapter, req_id);
if (!fsf_req)
/*
* Unknown request means that we have potentially memory
* corruption and must stop the machine immediatly.
*/
panic("error: unknown request id (%lx) on adapter %s.\n",
req_id, dev_name(&adapter->ccw_device->dev));
zfcp_reqlist_remove(adapter, fsf_req);
spin_unlock_irqrestore(&adapter->req_list_lock, flags);
fsf_req->sbal_response = sbal_idx;
fsf_req->qdio_inb_usage = atomic_read(&adapter->resp_q.count);
zfcp_fsf_req_complete(fsf_req);
}
static void zfcp_qdio_resp_put_back(struct zfcp_adapter *adapter, int processed)
{
struct zfcp_qdio_queue *queue = &adapter->resp_q;
struct ccw_device *cdev = adapter->ccw_device;
u8 count, start = queue->first;
unsigned int retval;
count = atomic_read(&queue->count) + processed;
retval = do_QDIO(cdev, QDIO_FLAG_SYNC_INPUT, 0, start, count);
if (unlikely(retval)) {
atomic_set(&queue->count, count);
/* FIXME: Recover this with an adapter reopen? */
} else {
queue->first += count;
queue->first %= QDIO_MAX_BUFFERS_PER_Q;
atomic_set(&queue->count, 0);
}
}
static void zfcp_qdio_int_resp(struct ccw_device *cdev, unsigned int qdio_err,
int queue_no, int first, int count,
unsigned long parm)
{
struct zfcp_adapter *adapter = (struct zfcp_adapter *) parm;
struct zfcp_qdio_queue *queue = &adapter->resp_q;
struct qdio_buffer_element *sbale;
int sbal_idx, sbale_idx, sbal_no;
if (unlikely(qdio_err)) {
zfcp_hba_dbf_event_qdio(adapter, qdio_err, first, count);
zfcp_qdio_handler_error(adapter, "qdires1");
return;
}
/*
* go through all SBALs from input queue currently
* returned by QDIO layer
*/
for (sbal_no = 0; sbal_no < count; sbal_no++) {
sbal_idx = (first + sbal_no) % QDIO_MAX_BUFFERS_PER_Q;
/* go through all SBALEs of SBAL */
for (sbale_idx = 0; sbale_idx < QDIO_MAX_ELEMENTS_PER_BUFFER;
sbale_idx++) {
sbale = zfcp_qdio_sbale(queue, sbal_idx, sbale_idx);
zfcp_qdio_reqid_check(adapter,
(unsigned long) sbale->addr,
sbal_idx);
if (likely(sbale->flags & SBAL_FLAGS_LAST_ENTRY))
break;
};
if (unlikely(!(sbale->flags & SBAL_FLAGS_LAST_ENTRY)))
dev_warn(&adapter->ccw_device->dev,
"A QDIO protocol error occurred, "
"operations continue\n");
}
/*
* put range of SBALs back to response queue
* (including SBALs which have already been free before)
*/
zfcp_qdio_resp_put_back(adapter, count);
}
/**
* zfcp_qdio_sbale_req - return ptr to SBALE of req_q for a struct zfcp_fsf_req
* @fsf_req: pointer to struct fsf_req
* Returns: pointer to qdio_buffer_element (SBALE) structure
*/
struct qdio_buffer_element *zfcp_qdio_sbale_req(struct zfcp_fsf_req *req)
{
return zfcp_qdio_sbale(&req->adapter->req_q, req->sbal_last, 0);
}
/**
* zfcp_qdio_sbale_curr - return curr SBALE on req_q for a struct zfcp_fsf_req
* @fsf_req: pointer to struct fsf_req
* Returns: pointer to qdio_buffer_element (SBALE) structure
*/
struct qdio_buffer_element *zfcp_qdio_sbale_curr(struct zfcp_fsf_req *req)
{
return zfcp_qdio_sbale(&req->adapter->req_q, req->sbal_last,
req->sbale_curr);
}
static void zfcp_qdio_sbal_limit(struct zfcp_fsf_req *fsf_req, int max_sbals)
{
int count = atomic_read(&fsf_req->adapter->req_q.count);
count = min(count, max_sbals);
fsf_req->sbal_limit = (fsf_req->sbal_first + count - 1)
% QDIO_MAX_BUFFERS_PER_Q;
}
static struct qdio_buffer_element *
zfcp_qdio_sbal_chain(struct zfcp_fsf_req *fsf_req, unsigned long sbtype)
{
struct qdio_buffer_element *sbale;
/* set last entry flag in current SBALE of current SBAL */
sbale = zfcp_qdio_sbale_curr(fsf_req);
sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
/* don't exceed last allowed SBAL */
if (fsf_req->sbal_last == fsf_req->sbal_limit)
return NULL;
/* set chaining flag in first SBALE of current SBAL */
sbale = zfcp_qdio_sbale_req(fsf_req);
sbale->flags |= SBAL_FLAGS0_MORE_SBALS;
/* calculate index of next SBAL */
fsf_req->sbal_last++;
fsf_req->sbal_last %= QDIO_MAX_BUFFERS_PER_Q;
/* keep this requests number of SBALs up-to-date */
fsf_req->sbal_number++;
/* start at first SBALE of new SBAL */
fsf_req->sbale_curr = 0;
/* set storage-block type for new SBAL */
sbale = zfcp_qdio_sbale_curr(fsf_req);
sbale->flags |= sbtype;
return sbale;
}
static struct qdio_buffer_element *
zfcp_qdio_sbale_next(struct zfcp_fsf_req *fsf_req, unsigned long sbtype)
{
if (fsf_req->sbale_curr == ZFCP_LAST_SBALE_PER_SBAL)
return zfcp_qdio_sbal_chain(fsf_req, sbtype);
fsf_req->sbale_curr++;
return zfcp_qdio_sbale_curr(fsf_req);
}
static void zfcp_qdio_undo_sbals(struct zfcp_fsf_req *fsf_req)
{
struct qdio_buffer **sbal = fsf_req->adapter->req_q.sbal;
int first = fsf_req->sbal_first;
int last = fsf_req->sbal_last;
int count = (last - first + QDIO_MAX_BUFFERS_PER_Q) %
QDIO_MAX_BUFFERS_PER_Q + 1;
zfcp_qdio_zero_sbals(sbal, first, count);
}
static int zfcp_qdio_fill_sbals(struct zfcp_fsf_req *fsf_req,
unsigned int sbtype, void *start_addr,
unsigned int total_length)
{
struct qdio_buffer_element *sbale;
unsigned long remaining, length;
void *addr;
/* split segment up */
for (addr = start_addr, remaining = total_length; remaining > 0;
addr += length, remaining -= length) {
sbale = zfcp_qdio_sbale_next(fsf_req, sbtype);
if (!sbale) {
atomic_inc(&fsf_req->adapter->qdio_outb_full);
zfcp_qdio_undo_sbals(fsf_req);
return -EINVAL;
}
/* new piece must not exceed next page boundary */
length = min(remaining,
(PAGE_SIZE - ((unsigned long)addr &
(PAGE_SIZE - 1))));
sbale->addr = addr;
sbale->length = length;
}
return 0;
}
/**
* zfcp_qdio_sbals_from_sg - fill SBALs from scatter-gather list
* @fsf_req: request to be processed
* @sbtype: SBALE flags
* @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_fsf_req *fsf_req, unsigned long sbtype,
struct scatterlist *sg, int max_sbals)
{
struct qdio_buffer_element *sbale;
int retval, bytes = 0;
/* figure out last allowed SBAL */
zfcp_qdio_sbal_limit(fsf_req, max_sbals);
/* set storage-block type for this request */
sbale = zfcp_qdio_sbale_req(fsf_req);
sbale->flags |= sbtype;
for (; sg; sg = sg_next(sg)) {
retval = zfcp_qdio_fill_sbals(fsf_req, sbtype, sg_virt(sg),
sg->length);
if (retval < 0)
return retval;
bytes += sg->length;
}
/* assume that no other SBALEs are to follow in the same SBAL */
sbale = zfcp_qdio_sbale_curr(fsf_req);
sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
return bytes;
}
/**
* zfcp_qdio_send - set PCI flag in first SBALE and send req to QDIO
* @fsf_req: pointer to struct zfcp_fsf_req
* Returns: 0 on success, error otherwise
*/
int zfcp_qdio_send(struct zfcp_fsf_req *fsf_req)
{
struct zfcp_adapter *adapter = fsf_req->adapter;
struct zfcp_qdio_queue *req_q = &adapter->req_q;
int first = fsf_req->sbal_first;
int count = fsf_req->sbal_number;
int retval;
unsigned int qdio_flags = QDIO_FLAG_SYNC_OUTPUT;
zfcp_qdio_account(adapter);
retval = do_QDIO(adapter->ccw_device, qdio_flags, 0, first, count);
if (unlikely(retval)) {
zfcp_qdio_zero_sbals(req_q->sbal, first, count);
return retval;
}
/* account for transferred buffers */
atomic_sub(count, &req_q->count);
req_q->first += count;
req_q->first %= QDIO_MAX_BUFFERS_PER_Q;
return 0;
}
/**
* 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
*/
int zfcp_qdio_allocate(struct zfcp_adapter *adapter)
{
struct qdio_initialize *init_data;
if (zfcp_qdio_buffers_enqueue(adapter->req_q.sbal) ||
zfcp_qdio_buffers_enqueue(adapter->resp_q.sbal))
return -ENOMEM;
init_data = &adapter->qdio_init_data;
init_data->cdev = adapter->ccw_device;
init_data->q_format = QDIO_ZFCP_QFMT;
memcpy(init_data->adapter_name, dev_name(&adapter->ccw_device->dev), 8);
ASCEBC(init_data->adapter_name, 8);
init_data->qib_param_field_format = 0;
init_data->qib_param_field = NULL;
init_data->input_slib_elements = NULL;
init_data->output_slib_elements = NULL;
init_data->no_input_qs = 1;
init_data->no_output_qs = 1;
init_data->input_handler = zfcp_qdio_int_resp;
init_data->output_handler = zfcp_qdio_int_req;
init_data->int_parm = (unsigned long) adapter;
init_data->flags = QDIO_INBOUND_0COPY_SBALS |
QDIO_OUTBOUND_0COPY_SBALS | QDIO_USE_OUTBOUND_PCIS;
init_data->input_sbal_addr_array =
(void **) (adapter->resp_q.sbal);
init_data->output_sbal_addr_array =
(void **) (adapter->req_q.sbal);
return qdio_allocate(init_data);
}
/**
* zfcp_close_qdio - close qdio queues for an adapter
*/
void zfcp_qdio_close(struct zfcp_adapter *adapter)
{
struct zfcp_qdio_queue *req_q;
int first, count;
if (!(atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP))
return;
/* clear QDIOUP flag, thus do_QDIO is not called during qdio_shutdown */
req_q = &adapter->req_q;
spin_lock_bh(&adapter->req_q_lock);
atomic_clear_mask(ZFCP_STATUS_ADAPTER_QDIOUP, &adapter->status);
spin_unlock_bh(&adapter->req_q_lock);
qdio_shutdown(adapter->ccw_device, QDIO_FLAG_CLEANUP_USING_CLEAR);
/* cleanup used outbound sbals */
count = atomic_read(&req_q->count);
if (count < QDIO_MAX_BUFFERS_PER_Q) {
first = (req_q->first + count) % QDIO_MAX_BUFFERS_PER_Q;
count = QDIO_MAX_BUFFERS_PER_Q - count;
zfcp_qdio_zero_sbals(req_q->sbal, first, count);
}
req_q->first = 0;
atomic_set(&req_q->count, 0);
adapter->resp_q.first = 0;
atomic_set(&adapter->resp_q.count, 0);
}
/**
* zfcp_qdio_open - prepare and initialize response queue
* @adapter: pointer to struct zfcp_adapter
* Returns: 0 on success, otherwise -EIO
*/
int zfcp_qdio_open(struct zfcp_adapter *adapter)
{
struct qdio_buffer_element *sbale;
int cc;
if (atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP)
return -EIO;
if (qdio_establish(&adapter->qdio_init_data))
goto failed_establish;
if (qdio_activate(adapter->ccw_device))
goto failed_qdio;
for (cc = 0; cc < QDIO_MAX_BUFFERS_PER_Q; cc++) {
sbale = &(adapter->resp_q.sbal[cc]->element[0]);
sbale->length = 0;
sbale->flags = SBAL_FLAGS_LAST_ENTRY;
sbale->addr = NULL;
}
if (do_QDIO(adapter->ccw_device, QDIO_FLAG_SYNC_INPUT, 0, 0,
QDIO_MAX_BUFFERS_PER_Q))
goto failed_qdio;
/* set index of first avalable SBALS / number of available SBALS */
adapter->req_q.first = 0;
atomic_set(&adapter->req_q.count, QDIO_MAX_BUFFERS_PER_Q);
return 0;
failed_qdio:
qdio_shutdown(adapter->ccw_device, QDIO_FLAG_CLEANUP_USING_CLEAR);
failed_establish:
dev_err(&adapter->ccw_device->dev,
"Setting up the QDIO connection to the FCP adapter failed\n");
return -EIO;
}
