Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   "Alastair D'Silva" <alastair@d-silva.org>
To:     alastair@d-silva.org
Cc:     "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>,
        "Oliver O'Halloran" <oohall@gmail.com>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Michael Ellerman <mpe@ellerman.id.au>,
        Frederic Barrat <fbarrat@linux.ibm.com>,
        Andrew Donnellan <ajd@linux.ibm.com>,
        Arnd Bergmann <arnd@arndb.de>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Dan Williams <dan.j.williams@intel.com>,
        Vishal Verma <vishal.l.verma@intel.com>,
        Dave Jiang <dave.jiang@intel.com>,
        Ira Weiny <ira.weiny@intel.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Mauro Carvalho Chehab <mchehab+samsung@kernel.org>,
        "David S. Miller" <davem@davemloft.net>,
        Rob Herring <robh@kernel.org>,
        Anton Blanchard <anton@ozlabs.org>,
        Krzysztof Kozlowski <krzk@kernel.org>,
        Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>,
        Madhavan Srinivasan <maddy@linux.vnet.ibm.com>,
        =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= <clg@kaod.org>,
        Anju T Sudhakar <anju@linux.vnet.ibm.com>,
        Hari Bathini <hbathini@linux.ibm.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Greg Kurz <groug@kaod.org>,
        Nicholas Piggin <npiggin@gmail.com>,
        Masahiro Yamada <yamada.masahiro@socionext.com>,
        Alexey Kardashevskiy <aik@ozlabs.ru>,
        linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
        linux-nvdimm@lists.01.org, linux-mm@kvack.org
Subject: [PATCH v4 21/25] nvdimm/ocxl: Implement the heartbeat command
Date:   Fri, 27 Mar 2020 18:11:58 +1100
Message-Id: <20200327071202.2159885-22-alastair@d-silva.org>
In-Reply-To: <20200327071202.2159885-1-alastair@d-silva.org>
References: <20200327071202.2159885-1-alastair@d-silva.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

The heartbeat admin command is a simple admin command that exercises
the communication mechanisms within the controller.

This patch issues a heartbeat command to the card during init to ensure
we can communicate with the card's controller.

Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
---
 drivers/nvdimm/ocxl/main.c | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/drivers/nvdimm/ocxl/main.c b/drivers/nvdimm/ocxl/main.c
index a4315472683c..2fbe3f2f77d9 100644
--- a/drivers/nvdimm/ocxl/main.c
+++ b/drivers/nvdimm/ocxl/main.c
@@ -272,6 +272,30 @@ static int setup_command_metadata(struct ocxlpmem *ocxlpmem)
 	return 0;
 }
 
+/**
+ * heartbeat() - Issue a heartbeat command to the controller
+ * @ocxlpmem: the device metadata
+ * Return: 0 if the controller responded correctly, negative on error
+ */
+static int heartbeat(struct ocxlpmem *ocxlpmem)
+{
+	int rc;
+
+	mutex_lock(&ocxlpmem->admin_command.lock);
+
+	rc = admin_command_execute(ocxlpmem, ADMIN_COMMAND_HEARTBEAT);
+	if (rc < 0)
+		goto out;
+	if (rc != STATUS_SUCCESS)
+		warn_status(ocxlpmem, "Unexpected status from heartbeat", rc);
+
+	(void)admin_response_handled(ocxlpmem);
+
+out:
+	mutex_unlock(&ocxlpmem->admin_command.lock);
+	return rc;
+}
+
 /**
  * allocate_minor() - Allocate a minor number to use for an OpenCAPI pmem device
  * @ocxlpmem: the device metadata
@@ -1460,6 +1484,12 @@ static int probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 		goto err;
 	}
 
+	rc = heartbeat(ocxlpmem);
+	if (rc) {
+		dev_err(&pdev->dev, "Heartbeat failed\n");
+		goto err;
+	}
+
 	elapsed = 0;
 	timeout = ocxlpmem->readiness_timeout +
 		  ocxlpmem->memory_available_timeout;
-- 
2.24.1