From 3223c01aa1cec60d59bd218aca5e202b558d225a Mon Sep 17 00:00:00 2001 From: "Matthew R. Ochs" Date: Wed, 21 Jun 2017 21:16:33 -0500 Subject: [PATCH] scsi: cxlflash: Support WS16 unmap The cxlflash driver supports performing a write-same16 to scrub virtual luns when they are released by a user. To date, AFUs for adapters that are supported by cxlflash do not have the capability to unmap as part of the WS operation. This can lead to fragmented flash devices which results in performance degradation. Future AFUs can optionally support unmap write-same commands and reflects this support via the context control register. This provides userspace applications with direct visibility such that they need not depend on a host API. Detect unmap support during cxlflash initialization by reading the context control register associated with the primary hardware queue. Update the existing write_same16() routine to set the unmap bit in the CDB when unmap is supported by the host. Signed-off-by: Matthew R. Ochs Signed-off-by: Uma Krishnan Signed-off-by: Martin K. Petersen --- drivers/scsi/cxlflash/common.h | 1 + drivers/scsi/cxlflash/main.c | 12 ++++++++++++ drivers/scsi/cxlflash/sislite.h | 1 + drivers/scsi/cxlflash/vlun.c | 1 + 4 files changed, 15 insertions(+) diff --git a/drivers/scsi/cxlflash/common.h b/drivers/scsi/cxlflash/common.h index a91151c4a4fc..e95e5a516b5e 100644 --- a/drivers/scsi/cxlflash/common.h +++ b/drivers/scsi/cxlflash/common.h @@ -147,6 +147,7 @@ struct cxlflash_cfg { wait_queue_head_t tmf_waitq; spinlock_t tmf_slock; bool tmf_active; + bool ws_unmap; /* Write-same unmap supported */ wait_queue_head_t reset_waitq; enum cxlflash_state state; async_cookie_t async_reset_cookie; diff --git a/drivers/scsi/cxlflash/main.c b/drivers/scsi/cxlflash/main.c index d3ad52ec5314..0cce442c260a 100644 --- a/drivers/scsi/cxlflash/main.c +++ b/drivers/scsi/cxlflash/main.c @@ -1812,6 +1812,18 @@ static int init_global(struct cxlflash_cfg *cfg) SISL_CTX_CAP_AFU_CMD | SISL_CTX_CAP_GSCSI_CMD), &hwq->ctrl_map->ctx_cap); } + + /* + * Determine write-same unmap support for host by evaluating the unmap + * sector support bit of the context control register associated with + * the primary hardware queue. Note that while this status is reflected + * in a context register, the outcome can be assumed to be host-wide. + */ + hwq = get_hwq(afu, PRIMARY_HWQ); + reg = readq_be(&hwq->host_map->ctx_ctrl); + if (reg & SISL_CTX_CTRL_UNMAP_SECTOR) + cfg->ws_unmap = true; + /* Initialize heartbeat */ afu->hb = readq_be(&afu->afu_map->global.regs.afu_hb); out: diff --git a/drivers/scsi/cxlflash/sislite.h b/drivers/scsi/cxlflash/sislite.h index d671fae19697..09daa86670fc 100644 --- a/drivers/scsi/cxlflash/sislite.h +++ b/drivers/scsi/cxlflash/sislite.h @@ -283,6 +283,7 @@ struct sisl_host_map { __be64 rrq_end; /* write sequence: start followed by end */ __be64 cmd_room; __be64 ctx_ctrl; /* least significant byte or b56:63 is LISN# */ +#define SISL_CTX_CTRL_UNMAP_SECTOR 0x8000000000000000ULL /* b0 */ __be64 mbox_w; /* restricted use */ __be64 sq_start; /* Submission Queue (R/W): write sequence and */ __be64 sq_end; /* inclusion semantics are the same as RRQ */ diff --git a/drivers/scsi/cxlflash/vlun.c b/drivers/scsi/cxlflash/vlun.c index 0800bcba5a00..bdfb93061460 100644 --- a/drivers/scsi/cxlflash/vlun.c +++ b/drivers/scsi/cxlflash/vlun.c @@ -446,6 +446,7 @@ static int write_same16(struct scsi_device *sdev, while (left > 0) { scsi_cmd[0] = WRITE_SAME_16; + scsi_cmd[1] = cfg->ws_unmap ? 0x8 : 0; put_unaligned_be64(offset, &scsi_cmd[2]); put_unaligned_be32(ws_limit < left ? ws_limit : left, &scsi_cmd[10]); -- 2.20.1