[RFC PATCH 04/14] nvmet: Implement CCR logpage

[Mohamed Khalfella <mkhalfella@purestorage.com>]

Defined by TP8028 Rapid Path Failure Recovery, CCR (Cross-Controller
Reset) log page contains an entry for each CCR request submitted to
source controller. Implement CCR logpage for nvme linux target.

Signed-off-by: Mohamed Khalfella <mkhalfella@purestorage.com>
---
 drivers/nvme/target/admin-cmd.c | 42 +++++++++++++++++++++++++++++++++
 include/linux/nvme.h            | 16 +++++++++++++
 2 files changed, 58 insertions(+)

diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c
index a55ca010d34f..d2892354bf81 100644
--- a/drivers/nvme/target/admin-cmd.c
+++ b/drivers/nvme/target/admin-cmd.c
@@ -220,6 +220,7 @@ static void nvmet_execute_get_supported_log_pages(struct nvmet_req *req)
 	logs->lids[NVME_LOG_FEATURES] = cpu_to_le32(NVME_LIDS_LSUPP);
 	logs->lids[NVME_LOG_RMI] = cpu_to_le32(NVME_LIDS_LSUPP);
 	logs->lids[NVME_LOG_RESERVATION] = cpu_to_le32(NVME_LIDS_LSUPP);
+	logs->lids[NVME_LOG_CCR] = cpu_to_le32(NVME_LIDS_LSUPP);
 
 	status = nvmet_copy_to_sgl(req, 0, logs, sizeof(*logs));
 	kfree(logs);
@@ -608,6 +609,45 @@ static void nvmet_execute_get_log_page_features(struct nvmet_req *req)
 	nvmet_req_complete(req, status);
 }
 
+static void nvmet_execute_get_log_page_ccr(struct nvmet_req *req)
+{
+	struct nvmet_ctrl *ctrl = req->sq->ctrl;
+	struct nvmet_ccr *ccr;
+	struct nvme_ccr_log *log;
+	int index = 0;
+	u16 status;
+
+	log = kzalloc(sizeof(*log), GFP_KERNEL);
+	if (!log) {
+		status = NVME_SC_INTERNAL;
+		goto out;
+	}
+
+	mutex_lock(&ctrl->lock);
+	list_for_each_entry(ccr, &ctrl->ccrs, entry) {
+		log->entries[index].icid = cpu_to_le16(ccr->icid);
+		log->entries[index].ciu = ccr->ciu;
+		log->entries[index].acid = cpu_to_le16(0xffff);
+
+		/* If ccr->ctrl is NULL then we know reset succeeded */
+		log->entries[index].ccrs = ccr->ctrl ? 0x00 : 0x01;
+		log->entries[index].ccrf = 0x03; /* Validated and Initiated */
+		index++;
+	}
+
+	/* Cleanup completed CCRs if requested */
+	if (req->cmd->get_log_page.lsp & 0x1)
+		nvmet_ctrl_cleanup_ccrs(ctrl, false);
+	mutex_unlock(&ctrl->lock);
+
+	log->ne = cpu_to_le16(index);
+	nvmet_clear_aen_bit(req, NVME_AEN_BIT_CCR_COMPLETE);
+	status = nvmet_copy_to_sgl(req, 0, log, sizeof(*log));
+	kfree(log);
+out:
+	nvmet_req_complete(req, status);
+}
+
 static void nvmet_execute_get_log_page(struct nvmet_req *req)
 {
 	if (!nvmet_check_transfer_len(req, nvmet_get_log_page_len(req->cmd)))
@@ -641,6 +681,8 @@ static void nvmet_execute_get_log_page(struct nvmet_req *req)
 		return nvmet_execute_get_log_page_rmi(req);
 	case NVME_LOG_RESERVATION:
 		return nvmet_execute_get_log_page_resv(req);
+	case NVME_LOG_CCR:
+		return nvmet_execute_get_log_page_ccr(req);
 	}
 	pr_debug("unhandled lid %d on qid %d\n",
 	       req->cmd->get_log_page.lid, req->sq->qid);
diff --git a/include/linux/nvme.h b/include/linux/nvme.h
index 0f305b317aa3..d51883122d65 100644
--- a/include/linux/nvme.h
+++ b/include/linux/nvme.h
@@ -1435,6 +1435,7 @@ enum {
 	NVME_LOG_FDP_CONFIGS	= 0x20,
 	NVME_LOG_DISC		= 0x70,
 	NVME_LOG_RESERVATION	= 0x80,
+	NVME_LOG_CCR		= 0x1E,
 	NVME_FWACT_REPL		= (0 << 3),
 	NVME_FWACT_REPL_ACTV	= (1 << 3),
 	NVME_FWACT_ACTV		= (2 << 3),
@@ -1458,6 +1459,21 @@ enum {
 	NVME_FIS_CSCPE	= 1 << 21,
 };
 
+struct nvme_ccr_log_entry {
+	__le16			icid;
+	__u8			ciu;
+	__u8			rsvd3;
+	__le16			acid;
+	__u8			ccrs;
+	__u8			ccrf;
+};
+
+struct nvme_ccr_log {
+	__le16				ne;
+	__u8				rsvd2[6];
+	struct nvme_ccr_log_entry	entries[NVMF_CCR_PER_PAGE];
+};
+
 /* NVMe Namespace Write Protect State */
 enum {
 	NVME_NS_NO_WRITE_PROTECT = 0,
-- 
2.51.2