Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / s390 / scsi / zfcp_qdio.c
diff --git a/kernel/drivers/s390/scsi/zfcp_qdio.c b/kernel/drivers/s390/scsi/zfcp_qdio.c
new file mode 100644 (file)
index 0000000..495e1cb
--- /dev/null
@@ -0,0 +1,504 @@
+/*
+ * zfcp device driver
+ *
+ * Setup and helper functions to access QDIO.
+ *
+ * Copyright IBM Corp. 2002, 2010
+ */
+
+#define KMSG_COMPONENT "zfcp"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <linux/slab.h>
+#include <linux/module.h>
+#include "zfcp_ext.h"
+#include "zfcp_qdio.h"
+
+static bool enable_multibuffer = 1;
+module_param_named(datarouter, enable_multibuffer, bool, 0400);
+MODULE_PARM_DESC(datarouter, "Enable hardware data router support (default on)");
+
+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_shutdown(adapter, 0, id);
+               return;
+       }
+       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_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;
+
+       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;
+       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 = (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 (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->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
+ * @max_sbals: upper bound for number of SBALs to be used
+ * 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 = sg_virt(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 - 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;
+       if (enable_multibuffer)
+               id->qdr_ac |= QDR_AC_MULTI_BUFFER_ENABLE;
+       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;
+       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;
+
+       zfcp_qdio_setup_init_data(&init_data, qdio);
+       init_waitqueue_head(&qdio->req_q_wq);
+
+       ret = qdio_allocate(&init_data);
+       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_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 (ssqd.qdioac2 & CHSC_AC2_MULTI_BUFFER_ENABLED) {
+               atomic_set_mask(ZFCP_STATUS_ADAPTER_MB_ACT, &adapter->status);
+               qdio->max_sbale_per_sbal = QDIO_MAX_ELEMENTS_PER_BUFFER;
+       } else {
+               atomic_clear_mask(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 = NULL;
+       }
+
+       if (do_QDIO(cdev, QDIO_FLAG_SYNC_INPUT, 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_set_mask(ZFCP_STATUS_ADAPTER_QDIOUP, &qdio->adapter->status);
+
+       if (adapter->scsi_host) {
+               adapter->scsi_host->sg_tablesize = qdio->max_sbale_per_req;
+               adapter->scsi_host->max_sectors = qdio->max_sbale_per_req * 8;
+       }
+
+       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;
+
+       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);
+
+       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);
+}