// SPDX-License-Identifier: GPL-2.0
/*
* zfcp device driver
*
* Setup and helper functions to access QDIO.
*
* Copyright IBM Corp. 2002, 2020
*/
#define KMSG_COMPONENT "zfcp"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
#include <linux/lockdep.h>
#include <linux/slab.h>
#include <linux/module.h>
#include "zfcp_ext.h"
#include "zfcp_qdio.h"
static bool enable_multibuffer = true;
module_param_named(datarouter, enable_multibuffer, bool, 0400);
MODULE_PARM_DESC(datarouter, "Enable hardware data router support (default on)");
#define ZFCP_QDIO_REQUEST_RESCAN_MSECS (MSEC_PER_SEC * 10)
#define ZFCP_QDIO_REQUEST_SCAN_MSECS MSEC_PER_SEC
static void zfcp_qdio_handler_error(struct zfcp_qdio *qdio, char *dbftag,
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_shutdown(adapter, 0, dbftag);
return;
}
zfcp_erp_adapter_reopen(adapter,
ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED |
ZFCP_STATUS_COMMON_ERP_FAILED, dbftag);
}
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_tod_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;
zfcp_qdio_handler_error(qdio, "qdireq1", qdio_err);
}
static void zfcp_qdio_request_tasklet(struct tasklet_struct *tasklet)
{
struct zfcp_qdio *qdio = from_tasklet(qdio, tasklet, request_tasklet);
struct ccw_device *cdev = qdio->adapter->ccw_device;
unsigned int start, error;
int completed;
completed = qdio_inspect_output_queue(cdev, 0, &start, &error);
if (completed > 0) {
if (error) {
zfcp_qdio_handler_error(qdio, "qdreqt1", error);
} else {
/* cleanup all SBALs being program-owned now */
zfcp_qdio_zero_sbals(qdio->req_q, start, completed);
spin_lock_irq(&qdio->stat_lock);
zfcp_qdio_account(qdio);
spin_unlock_irq(&qdio->stat_lock);
atomic_add(completed, &qdio->req_q_free);
wake_up(&qdio->req_q_wq);
}
}
if (atomic_read(&qdio->req_q_free) < QDIO_MAX_BUFFERS_PER_Q)
timer_reduce(&qdio->request_timer,
jiffies + msecs_to_jiffies(ZFCP_QDIO_REQUEST_RESCAN_MSECS));
}
static void zfcp_qdio_request_timer(struct timer_list *timer)
{
struct zfcp_qdio *qdio = from_timer(qdio, timer, request_timer);
tasklet_schedule(&qdio->request_tasklet);
}
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;
struct zfcp_adapter *adapter = qdio->adapter;
int sbal_no, sbal_idx;
if (unlikely(qdio_err)) {
if (zfcp_adapter_multi_buffer_active(adapter)) {
void *pl[ZFCP_QDIO_MAX_SBALS_PER_REQ + 1];
struct qdio_buffer_element *sbale;
u64 req_id;
u8 scount;
memset(pl, 0,
ZFCP_QDIO_MAX_SBALS_PER_REQ * sizeof(void *));
sbale = qdio->res_q[idx]->element;
req_id = dma64_to_u64(sbale->addr);
scount = min(sbale->scount + 1,
ZFCP_QDIO_MAX_SBALS_PER_REQ + 1);
/* incl. signaling SBAL */
for (sbal_no = 0; sbal_no < scount; sbal_no++) {
sbal_idx = (idx + sbal_no) %
QDIO_MAX_BUFFERS_PER_Q;
pl[sbal_no] = qdio->res_q[sbal_idx];
}
zfcp_dbf_hba_def_err(adapter, req_id, scount, pl);
}
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 (qdio_add_bufs_to_input_queue(cdev, 0, idx, count))
zfcp_erp_adapter_reopen(qdio->adapter, 0, "qdires2");
}
static void zfcp_qdio_irq_tasklet(struct tasklet_struct *tasklet)
{
struct zfcp_qdio *qdio = from_tasklet(qdio, tasklet, irq_tasklet);
struct ccw_device *cdev = qdio->adapter->ccw_device;
unsigned int start, error;
int completed;
if (atomic_read(&qdio->req_q_free) < QDIO_MAX_BUFFERS_PER_Q)
tasklet_schedule(&qdio->request_tasklet);
/* Check the Response Queue: */
completed = qdio_inspect_input_queue(cdev, 0, &start, &error);
if (completed < 0)
return;
if (completed > 0)
zfcp_qdio_int_resp(cdev, error, 0, start, completed,
(unsigned long) qdio);
if (qdio_start_irq(cdev))
/* More work pending: */
tasklet_schedule(&qdio->irq_tasklet);
}
static void zfcp_qdio_poll(struct ccw_device *cdev, unsigned long data)
{
struct zfcp_qdio *qdio = (struct zfcp_qdio *) data;
tasklet_schedule(&qdio->irq_tasklet);
}
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->eflags |= SBAL_EFLAGS_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->sflags |= SBAL_SFLAGS0_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->sflags |= 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 == qdio->max_sbale_per_sbal - 1)
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
* Returns: zero or -EINVAL on error
*/
int zfcp_qdio_sbals_from_sg(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
struct scatterlist *sg)
{
struct qdio_buffer_element *sbale;
/* set storage-block type for this request */
sbale = zfcp_qdio_sbale_req(qdio, q_req);
sbale->sflags |= 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 = u64_to_dma64(sg_phys(sg));
sbale->length = sg->length;
}
return 0;
}
static int zfcp_qdio_sbal_check(struct zfcp_qdio *qdio)
{
if (atomic_read(&qdio->req_q_free) ||
!(atomic_read(&qdio->adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP))
return 1;
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;
ret = wait_event_interruptible_lock_irq_timeout(qdio->req_q_wq,
zfcp_qdio_sbal_check(qdio), qdio->req_q_lock, 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");
}
return -EIO;
}
/**
* zfcp_qdio_send - 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;
/*
* This should actually be a spin_lock_bh(stat_lock), to protect against
* Request Queue completion processing in tasklet context.
* But we can't do so (and are safe), as we always get called with IRQs
* disabled by spin_lock_irq[save](req_q_lock).
*/
lockdep_assert_irqs_disabled();
spin_lock(&qdio->stat_lock);
zfcp_qdio_account(qdio);
spin_unlock(&qdio->stat_lock);
atomic_sub(sbal_number, &qdio->req_q_free);
retval = qdio_add_bufs_to_output_queue(qdio->adapter->ccw_device, 0,
q_req->sbal_first, sbal_number,
NULL);
if (unlikely(retval)) {
/* Failed to submit the IO, roll back our modifications. */
atomic_add(sbal_number, &qdio->req_q_free);
zfcp_qdio_zero_sbals(qdio->req_q, q_req->sbal_first,
sbal_number);
return retval;
}
if (atomic_read(&qdio->req_q_free) <= 2 * ZFCP_QDIO_MAX_SBALS_PER_REQ)
tasklet_schedule(&qdio->request_tasklet);
else
timer_reduce(&qdio->request_timer,
jiffies + msecs_to_jiffies(ZFCP_QDIO_REQUEST_SCAN_MSECS));
/* account for transferred buffers */
qdio->req_q_idx += sbal_number;
qdio->req_q_idx %= QDIO_MAX_BUFFERS_PER_Q;
return 0;
}
/**
* zfcp_qdio_allocate - allocate queue memory and initialize QDIO data
* @qdio: pointer to struct zfcp_qdio
* Returns: -ENOMEM on memory allocation error or return value from
* qdio_allocate
*/
static int zfcp_qdio_allocate(struct zfcp_qdio *qdio)
{
int ret;
ret = qdio_alloc_buffers(qdio->req_q, QDIO_MAX_BUFFERS_PER_Q);
if (ret)
return -ENOMEM;
ret = qdio_alloc_buffers(qdio->res_q, QDIO_MAX_BUFFERS_PER_Q);
if (ret)
goto free_req_q;
init_waitqueue_head(&qdio->req_q_wq);
ret = qdio_allocate(qdio->adapter->ccw_device, 1, 1);
if (ret)
goto free_res_q;
return 0;
free_res_q:
qdio_free_buffers(qdio->res_q, QDIO_MAX_BUFFERS_PER_Q);
free_req_q:
qdio_free_buffers(qdio->req_q, QDIO_MAX_BUFFERS_PER_Q);
return ret;
}
/**
* zfcp_qdio_close - 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 qdio_add_bufs_to_output_queue() is not called
* during qdio_shutdown().
*/
spin_lock_irq(&qdio->req_q_lock);
atomic_andnot(ZFCP_STATUS_ADAPTER_QDIOUP, &adapter->status);
spin_unlock_irq(&qdio->req_q_lock);
wake_up(&qdio->req_q_wq);
tasklet_disable(&qdio->irq_tasklet);
tasklet_disable(&qdio->request_tasklet);
del_timer_sync(&qdio->request_timer);
qdio_stop_irq(adapter->ccw_device);
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);
}
void zfcp_qdio_shost_update(struct zfcp_adapter *const adapter,
const struct zfcp_qdio *const qdio)
{
struct Scsi_Host *const shost = adapter->scsi_host;
if (shost == NULL)
return;
shost->sg_tablesize = qdio->max_sbale_per_req;
shost->max_sectors = qdio->max_sbale_per_req * 8;
}
/**
* 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 **input_sbals[1] = {qdio->res_q};
struct qdio_buffer **output_sbals[1] = {qdio->req_q};
struct qdio_buffer_element *sbale;
struct qdio_initialize init_data = {0};
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_andnot(ZFCP_STATUS_ADAPTER_SIOSL_ISSUED,
&qdio->adapter->status);
init_data.q_format = QDIO_ZFCP_QFMT;
init_data.qib_rflags = QIB_RFLAGS_ENABLE_DATA_DIV;
if (enable_multibuffer)
init_data.qdr_ac |= QDR_AC_MULTI_BUFFER_ENABLE;
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.irq_poll = zfcp_qdio_poll;
init_data.int_parm = (unsigned long) qdio;
init_data.input_sbal_addr_array = input_sbals;
init_data.output_sbal_addr_array = output_sbals;
if (qdio_establish(cdev, &init_data))
goto failed_establish;
if (qdio_get_ssqd_desc(cdev, &ssqd))
goto failed_qdio;
if (ssqd.qdioac2 & CHSC_AC2_DATA_DIV_ENABLED)
atomic_or(ZFCP_STATUS_ADAPTER_DATA_DIV_ENABLED,
&qdio->adapter->status);
if (ssqd.qdioac2 & CHSC_AC2_MULTI_BUFFER_ENABLED) {
atomic_or(ZFCP_STATUS_ADAPTER_MB_ACT, &adapter->status);
qdio->max_sbale_per_sbal = QDIO_MAX_ELEMENTS_PER_BUFFER;
} else {
atomic_andnot(ZFCP_STATUS_ADAPTER_MB_ACT, &adapter->status);
qdio->max_sbale_per_sbal = QDIO_MAX_ELEMENTS_PER_BUFFER - 1;
}
qdio->max_sbale_per_req =
ZFCP_QDIO_MAX_SBALS_PER_REQ * qdio->max_sbale_per_sbal
- 2;
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->eflags = SBAL_EFLAGS_LAST_ENTRY;
sbale->sflags = 0;
sbale->addr = 0;
}
if (qdio_add_bufs_to_input_queue(cdev, 0, 0, QDIO_MAX_BUFFERS_PER_Q))
goto failed_qdio;
/* set index of first available SBALS / number of available SBALS */
qdio->req_q_idx = 0;
atomic_set(&qdio->req_q_free, QDIO_MAX_BUFFERS_PER_Q);
atomic_or(ZFCP_STATUS_ADAPTER_QDIOUP, &qdio->adapter->status);
/* Enable processing for Request Queue completions: */
tasklet_enable(&qdio->request_tasklet);
/* Enable processing for QDIO interrupts: */
tasklet_enable(&qdio->irq_tasklet);
/* This results in a qdio_start_irq(): */
tasklet_schedule(&qdio->irq_tasklet);
zfcp_qdio_shost_update(adapter, qdio);
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)
{
if (!qdio)
return;
tasklet_kill(&qdio->irq_tasklet);
tasklet_kill(&qdio->request_tasklet);
if (qdio->adapter->ccw_device)
qdio_free(qdio->adapter->ccw_device);
qdio_free_buffers(qdio->req_q, QDIO_MAX_BUFFERS_PER_Q);
qdio_free_buffers(qdio->res_q, QDIO_MAX_BUFFERS_PER_Q);
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)) {
kfree(qdio);
return -ENOMEM;
}
spin_lock_init(&qdio->req_q_lock);
spin_lock_init(&qdio->stat_lock);
timer_setup(&qdio->request_timer, zfcp_qdio_request_timer, 0);
tasklet_setup(&qdio->irq_tasklet, zfcp_qdio_irq_tasklet);
tasklet_setup(&qdio->request_tasklet, zfcp_qdio_request_tasklet);
tasklet_disable(&qdio->irq_tasklet);
tasklet_disable(&qdio->request_tasklet);
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_or(ZFCP_STATUS_ADAPTER_SIOSL_ISSUED,
&adapter->status);
}
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