From 4ab4725757d2def1b450f165730eae3dd2e2010d Mon Sep 17 00:00:00 2001 From: Uma Krishnan Date: Fri, 7 Jul 2017 13:05:46 -0300 Subject: [PATCH] scsi: cxlflash: Add scsi command abort handler BugLink: http://bugs.launchpad.net/bugs/1702521 To date, CXL flash devices do not support a single command abort operation. Instead, the SISLite specification provides a context reset operation to cleanup all pending commands for a given context. When a context reset is successful, it is guaranteed that the AFU has aborted all currently pending I/O. This sequence is less invasive than a device or host reset and can be executed to support scsi command abort requests. Add eh_abort_handler callback support to process command timeouts and abort requests. Signed-off-by: Uma Krishnan Acked-by: Matthew R. Ochs Signed-off-by: Martin K. Petersen (cherry picked from commit 7c4c41f172b6d5dda1119ce5f59151bef732a058) Signed-off-by: Victor Aoqui Acked-by: Stefan Bader Acked-by: Seth Forshee Signed-off-by: Thadeu Lima de Souza Cascardo --- drivers/scsi/cxlflash/main.c | 61 ++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) diff --git a/drivers/scsi/cxlflash/main.c b/drivers/scsi/cxlflash/main.c index 0a3de42310ec..ceb247b5d1f2 100644 --- a/drivers/scsi/cxlflash/main.c +++ b/drivers/scsi/cxlflash/main.c @@ -228,6 +228,10 @@ static void flush_pending_cmds(struct hwq *hwq) * @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) @@ -237,9 +241,12 @@ 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); @@ -252,6 +259,11 @@ static int context_reset(struct hwq *hwq, __be64 __iomem *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; @@ -2255,6 +2267,54 @@ out: return rc; } +/** + * 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. @@ -2969,6 +3029,7 @@ static struct scsi_host_template driver_template = { .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, -- 2.39.2