MODULE_AUTHOR("Matthew R. Ochs <mrochs@linux.vnet.ibm.com>");
MODULE_LICENSE("GPL");
+static struct class *cxlflash_class;
+static u32 cxlflash_major;
+static DECLARE_BITMAP(cxlflash_minor, CXLFLASH_MAX_ADAPTERS);
+
/**
* process_cmd_err() - command error handler
* @cmd: AFU command that experienced the error.
struct afu *afu = cmd->parent;
struct cxlflash_cfg *cfg = afu->parent;
struct device *dev = &cfg->dev->dev;
+ struct hwq *hwq = get_hwq(afu, cmd->hwq_index);
bool cmd_is_tmf;
+ spin_lock_irqsave(&hwq->hsq_slock, lock_flags);
+ list_del(&cmd->list);
+ spin_unlock_irqrestore(&hwq->hsq_slock, lock_flags);
+
if (cmd->scp) {
scp = cmd->scp;
if (unlikely(cmd->sa.ioasc))
complete(&cmd->cevent);
}
+/**
+ * flush_pending_cmds() - flush all pending commands on this hardware queue
+ * @hwq: Hardware queue to flush.
+ *
+ * The hardware send queue lock associated with this hardware queue must be
+ * held when calling this routine.
+ */
+static void flush_pending_cmds(struct hwq *hwq)
+{
+ struct afu_cmd *cmd, *tmp;
+ struct scsi_cmnd *scp;
+
+ list_for_each_entry_safe(cmd, tmp, &hwq->pending_cmds, list) {
+ /* Bypass command when on a doneq, cmd_complete() will handle */
+ if (!list_empty(&cmd->queue))
+ continue;
+
+ list_del(&cmd->list);
+
+ if (cmd->scp) {
+ scp = cmd->scp;
+ scp->result = (DID_IMM_RETRY << 16);
+ scp->scsi_done(scp);
+ } else {
+ cmd->cmd_aborted = true;
+ complete(&cmd->cevent);
+ }
+ }
+}
+
/**
* context_reset() - reset context via specified register
* @hwq: Hardware queue owning the context to be reset.
* @reset_reg: MMIO register to perform reset.
*
+ * When the reset is successful, the SISLite specification guarantees that
+ * the AFU has aborted all currently pending I/O. Accordingly, these commands
+ * must be flushed.
+ *
* Return: 0 on success, -errno on failure
*/
static int context_reset(struct hwq *hwq, __be64 __iomem *reset_reg)
int rc = -ETIMEDOUT;
int nretry = 0;
u64 val = 0x1;
+ ulong lock_flags;
dev_dbg(dev, "%s: hwq=%p\n", __func__, hwq);
+ spin_lock_irqsave(&hwq->hsq_slock, lock_flags);
+
writeq_be(val, reset_reg);
do {
val = readq_be(reset_reg);
udelay(1 << nretry);
} while (nretry++ < MC_ROOM_RETRY_CNT);
+ if (!rc)
+ flush_pending_cmds(hwq);
+
+ spin_unlock_irqrestore(&hwq->hsq_slock, lock_flags);
+
dev_dbg(dev, "%s: returning rc=%d, val=%016llx nretry=%d\n",
__func__, rc, val, nretry);
return rc;
hwq->room = room - 1;
}
+ list_add(&cmd->list, &hwq->pending_cmds);
writeq_be((u64)&cmd->rcb, &hwq->host_map->ioarrin);
out:
spin_unlock_irqrestore(&hwq->hsq_slock, lock_flags);
hwq->hsq_curr++;
else
hwq->hsq_curr = hwq->hsq_start;
+
+ list_add(&cmd->list, &hwq->pending_cmds);
writeq_be((u64)hwq->hsq_curr, &hwq->host_map->sq_tail);
spin_unlock_irqrestore(&hwq->hsq_slock, lock_flags);
if (!timeout)
rc = -ETIMEDOUT;
+ if (cmd->cmd_aborted)
+ rc = -EAGAIN;
+
if (unlikely(cmd->sa.ioasc != 0)) {
dev_err(dev, "%s: cmd %02x failed, ioasc=%08x\n",
__func__, cmd->rcb.cdb[0], cmd->sa.ioasc);
struct afu *afu = cfg->afu;
struct device *dev = &cfg->dev->dev;
struct hwq *hwq;
+ ulong lock_flags;
if (!afu) {
dev_err(dev, "%s: returning with NULL afu\n", __func__);
if (index != PRIMARY_HWQ)
WARN_ON(cxl_release_context(hwq->ctx));
hwq->ctx = NULL;
+
+ spin_lock_irqsave(&hwq->hsq_slock, lock_flags);
+ flush_pending_cmds(hwq);
+ spin_unlock_irqrestore(&hwq->hsq_slock, lock_flags);
}
/**
}
}
+/**
+ * cxlflash_get_minor() - gets the first available minor number
+ *
+ * Return: Unique minor number that can be used to create the character device.
+ */
+static int cxlflash_get_minor(void)
+{
+ int minor;
+ long bit;
+
+ bit = find_first_zero_bit(cxlflash_minor, CXLFLASH_MAX_ADAPTERS);
+ if (bit >= CXLFLASH_MAX_ADAPTERS)
+ return -1;
+
+ minor = bit & MINORMASK;
+ set_bit(minor, cxlflash_minor);
+ return minor;
+}
+
+/**
+ * cxlflash_put_minor() - releases the minor number
+ * @minor: Minor number that is no longer needed.
+ */
+static void cxlflash_put_minor(int minor)
+{
+ clear_bit(minor, cxlflash_minor);
+}
+
+/**
+ * cxlflash_release_chrdev() - release the character device for the host
+ * @cfg: Internal structure associated with the host.
+ */
+static void cxlflash_release_chrdev(struct cxlflash_cfg *cfg)
+{
+ put_device(cfg->chardev);
+ device_unregister(cfg->chardev);
+ cfg->chardev = NULL;
+ cdev_del(&cfg->cdev);
+ cxlflash_put_minor(MINOR(cfg->cdev.dev));
+}
+
/**
* cxlflash_remove() - PCI entry point to tear down host
* @pdev: PCI device associated with the host.
cxlflash_stop_term_user_contexts(cfg);
switch (cfg->init_state) {
+ case INIT_STATE_CDEV:
+ cxlflash_release_chrdev(cfg);
case INIT_STATE_SCSI:
cxlflash_term_local_luns(cfg);
scsi_remove_host(cfg->host);
hwq->afu = cfg->afu;
hwq->index = index;
+ INIT_LIST_HEAD(&hwq->pending_cmds);
if (index == PRIMARY_HWQ)
ctx = cxl_get_context(cfg->dev);
}
/**
- * cxlflash_afu_sync() - builds and sends an AFU sync command
+ * send_afu_cmd() - builds and sends an internal AFU command
* @afu: AFU associated with the host.
- * @ctx_hndl_u: Identifies context requesting sync.
- * @res_hndl_u: Identifies resource requesting sync.
- * @mode: Type of sync to issue (lightweight, heavyweight, global).
+ * @rcb: Pre-populated IOARCB describing command to send.
*
- * The AFU can only take 1 sync command at a time. This routine enforces this
- * limitation by using a mutex to provide exclusive access to the AFU during
- * the sync. This design point requires calling threads to not be on interrupt
- * context due to the possibility of sleeping during concurrent sync operations.
+ * The AFU can only take one internal AFU command at a time. This limitation is
+ * enforced by using a mutex to provide exclusive access to the AFU during the
+ * operation. This design point requires calling threads to not be on interrupt
+ * context due to the possibility of sleeping during concurrent AFU operations.
*
- * AFU sync operations are only necessary and allowed when the device is
- * operating normally. When not operating normally, sync requests can occur as
- * part of cleaning up resources associated with an adapter prior to removal.
- * In this scenario, these requests are simply ignored (safe due to the AFU
- * going away).
+ * The command status is optionally passed back to the caller when the caller
+ * populates the IOASA field of the IOARCB with a pointer to an IOASA structure.
*
* Return:
* 0 on success, -errno on failure
*/
-int cxlflash_afu_sync(struct afu *afu, ctx_hndl_t ctx_hndl_u,
- res_hndl_t res_hndl_u, u8 mode)
+static int send_afu_cmd(struct afu *afu, struct sisl_ioarcb *rcb)
{
struct cxlflash_cfg *cfg = afu->parent;
struct device *dev = &cfg->dev->dev;
mutex_lock(&sync_active);
atomic_inc(&afu->cmds_active);
- buf = kzalloc(sizeof(*cmd) + __alignof__(*cmd) - 1, GFP_KERNEL);
+ buf = kmalloc(sizeof(*cmd) + __alignof__(*cmd) - 1, GFP_KERNEL);
if (unlikely(!buf)) {
dev_err(dev, "%s: no memory for command\n", __func__);
rc = -ENOMEM;
cmd = (struct afu_cmd *)PTR_ALIGN(buf, __alignof__(*cmd));
retry:
+ memset(cmd, 0, sizeof(*cmd));
+ memcpy(&cmd->rcb, rcb, sizeof(*rcb));
+ INIT_LIST_HEAD(&cmd->queue);
init_completion(&cmd->cevent);
cmd->parent = afu;
cmd->hwq_index = hwq->index;
-
- dev_dbg(dev, "%s: afu=%p cmd=%p ctx=%d nretry=%d\n",
- __func__, afu, cmd, ctx_hndl_u, nretry);
-
- cmd->rcb.req_flags = SISL_REQ_FLAGS_AFU_CMD;
cmd->rcb.ctx_id = hwq->ctx_hndl;
- cmd->rcb.msi = SISL_MSI_RRQ_UPDATED;
- cmd->rcb.timeout = MC_AFU_SYNC_TIMEOUT;
-
- cmd->rcb.cdb[0] = 0xC0; /* AFU Sync */
- cmd->rcb.cdb[1] = mode;
- /* The cdb is aligned, no unaligned accessors required */
- *((__be16 *)&cmd->rcb.cdb[2]) = cpu_to_be16(ctx_hndl_u);
- *((__be32 *)&cmd->rcb.cdb[4]) = cpu_to_be32(res_hndl_u);
+ dev_dbg(dev, "%s: afu=%p cmd=%p type=%02x nretry=%d\n",
+ __func__, afu, cmd, cmd->rcb.cdb[0], nretry);
rc = afu->send_cmd(afu, cmd);
if (unlikely(rc)) {
}
rc = wait_resp(afu, cmd);
- if (rc == -ETIMEDOUT) {
+ switch (rc) {
+ case -ETIMEDOUT:
rc = afu->context_reset(hwq);
- if (!rc && ++nretry < 2)
+ if (rc) {
+ cxlflash_schedule_async_reset(cfg);
+ break;
+ }
+ /* fall through to retry */
+ case -EAGAIN:
+ if (++nretry < 2)
goto retry;
- cxlflash_schedule_async_reset(cfg);
+ /* fall through to exit */
+ default:
+ break;
}
+ if (rcb->ioasa)
+ *rcb->ioasa = cmd->sa;
out:
atomic_dec(&afu->cmds_active);
mutex_unlock(&sync_active);
return rc;
}
+/**
+ * cxlflash_afu_sync() - builds and sends an AFU sync command
+ * @afu: AFU associated with the host.
+ * @ctx: Identifies context requesting sync.
+ * @res: Identifies resource requesting sync.
+ * @mode: Type of sync to issue (lightweight, heavyweight, global).
+ *
+ * AFU sync operations are only necessary and allowed when the device is
+ * operating normally. When not operating normally, sync requests can occur as
+ * part of cleaning up resources associated with an adapter prior to removal.
+ * In this scenario, these requests are simply ignored (safe due to the AFU
+ * going away).
+ *
+ * Return:
+ * 0 on success, -errno on failure
+ */
+int cxlflash_afu_sync(struct afu *afu, ctx_hndl_t ctx, res_hndl_t res, u8 mode)
+{
+ struct cxlflash_cfg *cfg = afu->parent;
+ struct device *dev = &cfg->dev->dev;
+ struct sisl_ioarcb rcb = { 0 };
+
+ dev_dbg(dev, "%s: afu=%p ctx=%u res=%u mode=%u\n",
+ __func__, afu, ctx, res, mode);
+
+ rcb.req_flags = SISL_REQ_FLAGS_AFU_CMD;
+ rcb.msi = SISL_MSI_RRQ_UPDATED;
+ rcb.timeout = MC_AFU_SYNC_TIMEOUT;
+
+ rcb.cdb[0] = SISL_AFU_CMD_SYNC;
+ rcb.cdb[1] = mode;
+ put_unaligned_be16(ctx, &rcb.cdb[2]);
+ put_unaligned_be32(res, &rcb.cdb[4]);
+
+ return send_afu_cmd(afu, &rcb);
+}
+
+/**
+ * cxlflash_eh_abort_handler() - abort a SCSI command
+ * @scp: SCSI command to abort.
+ *
+ * CXL Flash devices do not support a single command abort. Reset the context
+ * as per SISLite specification. Flush any pending commands in the hardware
+ * queue before the reset.
+ *
+ * Return: SUCCESS/FAILED as defined in scsi/scsi.h
+ */
+static int cxlflash_eh_abort_handler(struct scsi_cmnd *scp)
+{
+ int rc = FAILED;
+ struct Scsi_Host *host = scp->device->host;
+ struct cxlflash_cfg *cfg = shost_priv(host);
+ struct afu_cmd *cmd = sc_to_afuc(scp);
+ struct device *dev = &cfg->dev->dev;
+ struct afu *afu = cfg->afu;
+ struct hwq *hwq = get_hwq(afu, cmd->hwq_index);
+
+ dev_dbg(dev, "%s: (scp=%p) %d/%d/%d/%llu "
+ "cdb=(%08x-%08x-%08x-%08x)\n", __func__, scp, host->host_no,
+ scp->device->channel, scp->device->id, scp->device->lun,
+ get_unaligned_be32(&((u32 *)scp->cmnd)[0]),
+ get_unaligned_be32(&((u32 *)scp->cmnd)[1]),
+ get_unaligned_be32(&((u32 *)scp->cmnd)[2]),
+ get_unaligned_be32(&((u32 *)scp->cmnd)[3]));
+
+ /* When the state is not normal, another reset/reload is in progress.
+ * Return failed and the mid-layer will invoke host reset handler.
+ */
+ if (cfg->state != STATE_NORMAL) {
+ dev_dbg(dev, "%s: Invalid state for abort, state=%d\n",
+ __func__, cfg->state);
+ goto out;
+ }
+
+ rc = afu->context_reset(hwq);
+ if (unlikely(rc))
+ goto out;
+
+ rc = SUCCESS;
+
+out:
+ dev_dbg(dev, "%s: returning rc=%d\n", __func__, rc);
+ return rc;
+}
+
/**
* cxlflash_eh_device_reset_handler() - reset a single LUN
* @scp: SCSI command to send.
.ioctl = cxlflash_ioctl,
.proc_name = CXLFLASH_NAME,
.queuecommand = cxlflash_queuecommand,
+ .eh_abort_handler = cxlflash_eh_abort_handler,
.eh_device_reset_handler = cxlflash_eh_device_reset_handler,
.eh_host_reset_handler = cxlflash_eh_host_reset_handler,
.change_queue_depth = cxlflash_change_queue_depth,
scsi_scan_host(cfg->host);
}
+/**
+ * cxlflash_chr_open() - character device open handler
+ * @inode: Device inode associated with this character device.
+ * @file: File pointer for this device.
+ *
+ * Only users with admin privileges are allowed to open the character device.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+static int cxlflash_chr_open(struct inode *inode, struct file *file)
+{
+ struct cxlflash_cfg *cfg;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EACCES;
+
+ cfg = container_of(inode->i_cdev, struct cxlflash_cfg, cdev);
+ file->private_data = cfg;
+
+ return 0;
+}
+
+/*
+ * Character device file operations
+ */
+static const struct file_operations cxlflash_chr_fops = {
+ .owner = THIS_MODULE,
+ .open = cxlflash_chr_open,
+};
+
+/**
+ * init_chrdev() - initialize the character device for the host
+ * @cfg: Internal structure associated with the host.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+static int init_chrdev(struct cxlflash_cfg *cfg)
+{
+ struct device *dev = &cfg->dev->dev;
+ struct device *char_dev;
+ dev_t devno;
+ int minor;
+ int rc = 0;
+
+ minor = cxlflash_get_minor();
+ if (unlikely(minor < 0)) {
+ dev_err(dev, "%s: Exhausted allowed adapters\n", __func__);
+ rc = -ENOSPC;
+ goto out;
+ }
+
+ devno = MKDEV(cxlflash_major, minor);
+ cdev_init(&cfg->cdev, &cxlflash_chr_fops);
+
+ rc = cdev_add(&cfg->cdev, devno, 1);
+ if (rc) {
+ dev_err(dev, "%s: cdev_add failed rc=%d\n", __func__, rc);
+ goto err1;
+ }
+
+ char_dev = device_create(cxlflash_class, NULL, devno,
+ NULL, "cxlflash%d", minor);
+ if (IS_ERR(char_dev)) {
+ rc = PTR_ERR(char_dev);
+ dev_err(dev, "%s: device_create failed rc=%d\n",
+ __func__, rc);
+ goto err2;
+ }
+
+ cfg->chardev = char_dev;
+out:
+ dev_dbg(dev, "%s: returning rc=%d\n", __func__, rc);
+ return rc;
+err2:
+ cdev_del(&cfg->cdev);
+err1:
+ cxlflash_put_minor(minor);
+ goto out;
+}
+
/**
* cxlflash_probe() - PCI entry point to add host
* @pdev: PCI device associated with the host.
}
cfg->init_state = INIT_STATE_SCSI;
+ rc = init_chrdev(cfg);
+ if (rc) {
+ dev_err(dev, "%s: init_chrdev failed rc=%d\n", __func__, rc);
+ goto out_remove;
+ }
+ cfg->init_state = INIT_STATE_CDEV;
+
if (wq_has_sleeper(&cfg->reset_waitq)) {
cfg->state = STATE_PROBED;
wake_up_all(&cfg->reset_waitq);
scsi_unblock_requests(cfg->host);
}
+/**
+ * cxlflash_devnode() - provides devtmpfs for devices in the cxlflash class
+ * @dev: Character device.
+ * @mode: Mode that can be used to verify access.
+ *
+ * Return: Allocated string describing the devtmpfs structure.
+ */
+static char *cxlflash_devnode(struct device *dev, umode_t *mode)
+{
+ return kasprintf(GFP_KERNEL, "cxlflash/%s", dev_name(dev));
+}
+
+/**
+ * cxlflash_class_init() - create character device class
+ *
+ * Return: 0 on success, -errno on failure
+ */
+static int cxlflash_class_init(void)
+{
+ dev_t devno;
+ int rc = 0;
+
+ rc = alloc_chrdev_region(&devno, 0, CXLFLASH_MAX_ADAPTERS, "cxlflash");
+ if (unlikely(rc)) {
+ pr_err("%s: alloc_chrdev_region failed rc=%d\n", __func__, rc);
+ goto out;
+ }
+
+ cxlflash_major = MAJOR(devno);
+
+ cxlflash_class = class_create(THIS_MODULE, "cxlflash");
+ if (IS_ERR(cxlflash_class)) {
+ rc = PTR_ERR(cxlflash_class);
+ pr_err("%s: class_create failed rc=%d\n", __func__, rc);
+ goto err;
+ }
+
+ cxlflash_class->devnode = cxlflash_devnode;
+out:
+ pr_debug("%s: returning rc=%d\n", __func__, rc);
+ return rc;
+err:
+ unregister_chrdev_region(devno, CXLFLASH_MAX_ADAPTERS);
+ goto out;
+}
+
+/**
+ * cxlflash_class_exit() - destroy character device class
+ */
+static void cxlflash_class_exit(void)
+{
+ dev_t devno = MKDEV(cxlflash_major, 0);
+
+ class_destroy(cxlflash_class);
+ unregister_chrdev_region(devno, CXLFLASH_MAX_ADAPTERS);
+}
+
static const struct pci_error_handlers cxlflash_err_handler = {
.error_detected = cxlflash_pci_error_detected,
.slot_reset = cxlflash_pci_slot_reset,
*/
static int __init init_cxlflash(void)
{
+ int rc;
+
check_sizes();
cxlflash_list_init();
+ rc = cxlflash_class_init();
+ if (unlikely(rc))
+ goto out;
- return pci_register_driver(&cxlflash_driver);
+ rc = pci_register_driver(&cxlflash_driver);
+ if (unlikely(rc))
+ goto err;
+out:
+ pr_debug("%s: returning rc=%d\n", __func__, rc);
+ return rc;
+err:
+ cxlflash_class_exit();
+ goto out;
}
/**
cxlflash_free_errpage();
pci_unregister_driver(&cxlflash_driver);
+ cxlflash_class_exit();
}
module_init(init_cxlflash);
projects / mirror_ubuntu-zesty-kernel.git / blobdiff