Introduce support for enhanced I/O error handling.
Signed-off-by: Matthew R. Ochs <mrochs@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Manoj N. Kumar <manoj@xxxxxxxxxxxxxxxxxx>
---
drivers/scsi/cxlflash/Kconfig | 2 +-
drivers/scsi/cxlflash/common.h | 11 ++-
drivers/scsi/cxlflash/main.c | 166 ++++++++++++++++++++++++++++++++++++++---
drivers/scsi/cxlflash/main.h | 4 +
4 files changed, 170 insertions(+), 13 deletions(-)
diff --git a/drivers/scsi/cxlflash/Kconfig b/drivers/scsi/cxlflash/Kconfig
index c707508..c052104 100644
--- a/drivers/scsi/cxlflash/Kconfig
+++ b/drivers/scsi/cxlflash/Kconfig
@@ -4,7 +4,7 @@
config CXLFLASH
tristate "Support for IBM CAPI Flash"
- depends on PCI && SCSI && CXL
+ depends on PCI && SCSI && CXL && EEH
default m
help
Allows CAPI Accelerated IO to Flash
diff --git a/drivers/scsi/cxlflash/common.h b/drivers/scsi/cxlflash/common.h
index fe86bfe..7e663f4 100644
--- a/drivers/scsi/cxlflash/common.h
+++ b/drivers/scsi/cxlflash/common.h
@@ -76,6 +76,12 @@ enum cxlflash_init_state {
INIT_STATE_SCSI
};
+enum cxlflash_state {
+ STATE_NORMAL, /* Normal running state, everything good */
+ STATE_LIMBO, /* Limbo running state, trying to reset/recover */
+ STATE_FAILTERM /* Failed/terminating state, error out users/threads */
+};
+
/*
* Each context has its own set of resource handles that is visible
* only from that context.
@@ -91,8 +97,6 @@ struct cxlflash_cfg {
ulong cxlflash_regs_pci;
- wait_queue_head_t eeh_waitq;
-
struct work_struct work_q;
enum cxlflash_init_state init_state;
enum cxlflash_lr_state lr_state;
@@ -105,7 +109,8 @@ struct cxlflash_cfg {
wait_queue_head_t tmf_waitq;
bool tmf_active;
- u8 err_recovery_active:1;
+ wait_queue_head_t limbo_waitq;
+ enum cxlflash_state state;
};
struct afu_cmd {
diff --git a/drivers/scsi/cxlflash/main.c b/drivers/scsi/cxlflash/main.c
index 76a7286..18359d4 100644
--- a/drivers/scsi/cxlflash/main.c
+++ b/drivers/scsi/cxlflash/main.c
@@ -380,6 +380,18 @@ static int cxlflash_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scp)
}
spin_unlock_irqrestore(&cfg->tmf_waitq.lock, lock_flags);
+ switch (cfg->state) {
+ case STATE_LIMBO:
+ pr_debug_ratelimited("%s: device in limbo!\n", __func__);
+ rc = SCSI_MLQUEUE_HOST_BUSY;
+ goto out;
+ case STATE_FAILTERM:
+ pr_debug_ratelimited("%s: device has failed!\n", __func__);
+ goto error;
+ default:
+ break;
+ }
+
cmd = cxlflash_cmd_checkout(afu);
if (unlikely(!cmd)) {
pr_err("%s: could not get a free command\n", __func__);
@@ -428,6 +440,10 @@ static int cxlflash_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scp)
out:
return rc;
+error:
+ scp->result = (DID_NO_CONNECT << 16);
+ scp->scsi_done(scp);
+ return 0;
}
/**
@@ -455,9 +471,21 @@ static int cxlflash_eh_device_reset_handler(struct scsi_cmnd *scp)
get_unaligned_be32(&((u32 *)scp->cmnd)[2]),
get_unaligned_be32(&((u32 *)scp->cmnd)[3]));
- rcr = send_tmf(afu, scp, TMF_LUN_RESET);
- if (unlikely(rcr))
+ switch (cfg->state) {
+ case STATE_NORMAL:
+ rcr = send_tmf(afu, scp, TMF_LUN_RESET);
+ if (unlikely(rcr))
+ rc = FAILED;
+ break;
+ case STATE_LIMBO:
+ wait_event(cfg->limbo_waitq, cfg->state != STATE_LIMBO);
+ if (cfg->state == STATE_NORMAL)
+ break;
+ /* fall through */
+ default:
rc = FAILED;
+ break;
+ }
pr_debug("%s: returning rc=%d\n", __func__, rc);
return rc;
@@ -487,11 +515,27 @@ static int cxlflash_eh_host_reset_handler(struct scsi_cmnd *scp)
get_unaligned_be32(&((u32 *)scp->cmnd)[2]),
get_unaligned_be32(&((u32 *)scp->cmnd)[3]));
- rcr = cxlflash_afu_reset(cfg);
- if (rcr == 0)
- rc = SUCCESS;
- else
+ switch (cfg->state) {
+ case STATE_NORMAL:
+ cfg->state = STATE_LIMBO;
+ scsi_block_requests(cfg->host);
+
+ rcr = cxlflash_afu_reset(cfg);
+ if (!rcr)
+ rc = FAILED;
+ cfg->state = STATE_NORMAL;
+ wake_up_all(&cfg->limbo_waitq);
+ scsi_unblock_requests(cfg->host);
+ break;
+ case STATE_LIMBO:
+ wait_event(cfg->limbo_waitq, cfg->state != STATE_LIMBO);
+ if (cfg->state == STATE_NORMAL)
+ break;
+ /* fall through */
+ default:
rc = FAILED;
+ break;
+ }
pr_debug("%s: returning rc=%d\n", __func__, rc);
return rc;
@@ -642,7 +686,7 @@ static void cxlflash_wait_for_pci_err_recovery(struct cxlflash_cfg *cfg)
struct pci_dev *pdev = cfg->dev;
if (pci_channel_offline(pdev))
- wait_event_timeout(cfg->eeh_waitq,
+ wait_event_timeout(cfg->limbo_waitq,
!pci_channel_offline(pdev),
CXLFLASH_PCI_ERROR_RECOVERY_TIMEOUT);
}
@@ -825,6 +869,8 @@ static void cxlflash_remove(struct pci_dev *pdev)
!cfg->tmf_active);
spin_unlock_irqrestore(&cfg->tmf_waitq.lock, lock_flags);
+ cfg->state = STATE_FAILTERM;
+
switch (cfg->init_state) {
case INIT_STATE_SCSI:
scsi_remove_host(cfg->host);
@@ -1879,6 +1925,8 @@ static int init_afu(struct cxlflash_cfg *cfg)
struct afu *afu = cfg->afu;
struct device *dev = &cfg->dev->dev;
+ cxl_perst_reloads_same_image(cfg->cxl_afu, true);
+
rc = init_mc(cfg);
if (rc) {
dev_err(dev, "%s: call to init_mc failed, rc=%d!\n",
@@ -2021,6 +2069,12 @@ void cxlflash_wait_resp(struct afu *afu, struct afu_cmd *cmd)
* the sync. This design point requires calling threads to not be on interrupt
* context due to the possibility of sleeping during concurrent sync 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).
+ *
* Return:
* 0 on success
* -1 on failure
@@ -2028,11 +2082,17 @@ void cxlflash_wait_resp(struct afu *afu, struct afu_cmd *cmd)
int cxlflash_afu_sync(struct afu *afu, ctx_hndl_t ctx_hndl_u,
res_hndl_t res_hndl_u, u8 mode)
{
+ struct cxlflash_cfg *cfg = afu->parent;
struct afu_cmd *cmd = NULL;
int rc = 0;
int retry_cnt = 0;
static DEFINE_MUTEX(sync_active);
+ if (cfg->state != STATE_NORMAL) {
+ pr_debug("%s: Sync not required! (%u)\n", __func__, cfg->state);
+ return 0;
+ }
+
mutex_lock(&sync_active);
retry:
cmd = cxlflash_cmd_checkout(afu);
@@ -2122,6 +2182,11 @@ static void cxlflash_worker_thread(struct work_struct *work)
int port;
ulong lock_flags;
+ /* Avoid MMIO if the device has failed */
+
+ if (cfg->state != STATE_NORMAL)
+ return;
+
spin_lock_irqsave(cfg->host->host_lock, lock_flags);
if (cfg->lr_state == LINK_RESET_REQUIRED) {
@@ -2200,10 +2265,9 @@ static int cxlflash_probe(struct pci_dev *pdev,
cfg->dev = pdev;
cfg->dev_id = (struct pci_device_id *)dev_id;
cfg->mcctx = NULL;
- cfg->err_recovery_active = 0;
init_waitqueue_head(&cfg->tmf_waitq);
- init_waitqueue_head(&cfg->eeh_waitq);
+ init_waitqueue_head(&cfg->limbo_waitq);
INIT_WORK(&cfg->work_q, cxlflash_worker_thread);
cfg->lr_state = LINK_RESET_INVALID;
@@ -2259,6 +2323,89 @@ out_remove:
goto out;
}
+/**
+ * cxlflash_pci_error_detected() - called when a PCI error is detected
+ * @pdev: PCI device struct.
+ * @state: PCI channel state.
+ *
+ * Return: PCI_ERS_RESULT_NEED_RESET or PCI_ERS_RESULT_DISCONNECT
+ */
+static pci_ers_result_t cxlflash_pci_error_detected(struct pci_dev *pdev,
+ pci_channel_state_t state)
+{
+ struct cxlflash_cfg *cfg = pci_get_drvdata(pdev);
+
+ pr_debug("%s: pdev=%p state=%u\n", __func__, pdev, state);
+
+ switch (state) {
+ case pci_channel_io_frozen:
+ cfg->state = STATE_LIMBO;
+
+ /* Turn off legacy I/O */
+ scsi_block_requests(cfg->host);
+
+ term_mc(cfg, UNDO_START);
+ stop_afu(cfg);
+
+ return PCI_ERS_RESULT_NEED_RESET;
+ case pci_channel_io_perm_failure:
+ cfg->state = STATE_FAILTERM;
+ wake_up_all(&cfg->limbo_waitq);
+ scsi_unblock_requests(cfg->host);
+ return PCI_ERS_RESULT_DISCONNECT;
+ default:
+ break;
+ }
+ return PCI_ERS_RESULT_NEED_RESET;
+}
+
+/**
+ * cxlflash_pci_slot_reset() - called when PCI slot has been reset
+ * @pdev: PCI device struct.
+ *
+ * This routine is called by the pci error recovery code after the PCI
+ * slot has been reset, just before we should resume normal operations.
+ *
+ * Return: PCI_ERS_RESULT_RECOVERED or PCI_ERS_RESULT_DISCONNECT
+ */
+static pci_ers_result_t cxlflash_pci_slot_reset(struct pci_dev *pdev)
+{
+ int rc = 0;
+ struct cxlflash_cfg *cfg = pci_get_drvdata(pdev);
+ struct device *dev = &cfg->dev->dev;
+
+ pr_debug("%s: pdev=%p\n", __func__, pdev);
+
+ rc = init_afu(cfg);
+ if (unlikely(rc)) {
+ dev_err(dev, "%s: EEH recovery failed! (%d)\n", __func__, rc);
+ return PCI_ERS_RESULT_DISCONNECT;
+ }
+
+ return PCI_ERS_RESULT_RECOVERED;
+}
+
+/**
+ * cxlflash_pci_resume() - called when normal operation can resume
+ * @pdev: PCI device struct
+ */
+static void cxlflash_pci_resume(struct pci_dev *pdev)
+{
+ struct cxlflash_cfg *cfg = pci_get_drvdata(pdev);
+
+ pr_debug("%s: pdev=%p\n", __func__, pdev);
+
+ cfg->state = STATE_NORMAL;
+ wake_up_all(&cfg->limbo_waitq);
+ scsi_unblock_requests(cfg->host);
+}
+
+static const struct pci_error_handlers cxlflash_err_handler = {
+ .error_detected = cxlflash_pci_error_detected,
+ .slot_reset = cxlflash_pci_slot_reset,
+ .resume = cxlflash_pci_resume,
+};
+
/*
* PCI device structure
*/
@@ -2267,6 +2414,7 @@ static struct pci_driver cxlflash_driver = {
.id_table = cxlflash_pci_table,
.probe = cxlflash_probe,
.remove = cxlflash_remove,
+ .err_handler = &cxlflash_err_handler,
};
/**
diff --git a/drivers/scsi/cxlflash/main.h b/drivers/scsi/cxlflash/main.h
index 7f890cc..7232536 100644
--- a/drivers/scsi/cxlflash/main.h
+++ b/drivers/scsi/cxlflash/main.h
@@ -101,4 +101,8 @@ struct asyc_intr_info {
#define LINK_RESET 0x02
};
+#ifndef CONFIG_CXL_EEH
+#define cxl_perst_reloads_same_image(_a, _b) do { } while (0)
+#endif
+
#endif /* _CXLFLASH_MAIN_H */
--
2.1.0
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