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From:   "Alastair D'Silva" <alastair@au1.ibm.com>
To:     alastair@d-silva.org
Cc:     "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>,
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        linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
        linux-nvdimm@lists.01.org, linux-mm@kvack.org
Subject: [PATCH v3 19/27] powerpc/powernv/pmem: Add an IOCTL to report controller statistics
Date:   Fri, 21 Feb 2020 14:27:12 +1100
In-Reply-To: <20200221032720.33893-1-alastair@au1.ibm.com>
References: <20200221032720.33893-1-alastair@au1.ibm.com>
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From: Alastair D'Silva <alastair@d-silva.org>

The controller can report a number of statistics that are useful
in evaluating the performance and reliability of the card.

This patch exposes this information via an IOCTL.

Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
---
 arch/powerpc/platforms/powernv/pmem/ocxl.c | 185 +++++++++++++++++++++
 include/uapi/nvdimm/ocxl-pmem.h            |  17 ++
 2 files changed, 202 insertions(+)

diff --git a/arch/powerpc/platforms/powernv/pmem/ocxl.c b/arch/powerpc/platforms/powernv/pmem/ocxl.c
index 2cabafe1fc58..009d4fd29e7d 100644
--- a/arch/powerpc/platforms/powernv/pmem/ocxl.c
+++ b/arch/powerpc/platforms/powernv/pmem/ocxl.c
@@ -758,6 +758,186 @@ static int ioctl_controller_dump_complete(struct ocxlpmem *ocxlpmem)
 				    GLOBAL_MMIO_HCI_CONTROLLER_DUMP_COLLECTED);
 }
 
+/**
+ * controller_stats_header_parse() - Parse the first 64 bits of the controller stats admin command response
+ * @ocxlpmem: the device metadata
+ * @length: out, returns the number of bytes in the response (excluding the 64 bit header)
+ */
+static int controller_stats_header_parse(struct ocxlpmem *ocxlpmem,
+	u32 *length)
+{
+	int rc;
+	u64 val;
+
+	u16 data_identifier;
+	u32 data_length;
+
+	rc = ocxl_global_mmio_read64(ocxlpmem->ocxl_afu,
+				     ocxlpmem->admin_command.data_offset,
+				     OCXL_LITTLE_ENDIAN, &val);
+	if (rc)
+		return rc;
+
+	data_identifier = val >> 48;
+	data_length = val & 0xFFFFFFFF;
+
+	if (data_identifier != 0x4353) { // 'CS'
+		dev_err(&ocxlpmem->dev,
+			"Bad data identifier for controller stats, expected 'CS', got '%-.*s'\n",
+			2, (char *)&data_identifier);
+		return -EINVAL;
+	}
+
+	*length = data_length;
+	return 0;
+}
+
+static int ioctl_controller_stats(struct ocxlpmem *ocxlpmem,
+				  struct ioctl_ocxl_pmem_controller_stats __user *uarg)
+{
+	struct ioctl_ocxl_pmem_controller_stats args;
+	u32 length;
+	int rc;
+	u64 val;
+
+	memset(&args, '\0', sizeof(args));
+
+	mutex_lock(&ocxlpmem->admin_command.lock);
+
+	rc = admin_command_request(ocxlpmem, ADMIN_COMMAND_CONTROLLER_STATS);
+	if (rc)
+		goto out;
+
+	rc = ocxl_global_mmio_write64(ocxlpmem->ocxl_afu,
+				      ocxlpmem->admin_command.request_offset + 0x08,
+				      OCXL_LITTLE_ENDIAN, 0);
+	if (rc)
+		goto out;
+
+	rc = admin_command_execute(ocxlpmem);
+	if (rc)
+		goto out;
+
+
+	rc = admin_command_complete_timeout(ocxlpmem,
+					    ADMIN_COMMAND_CONTROLLER_STATS);
+	if (rc < 0) {
+		dev_warn(&ocxlpmem->dev, "Controller stats timed out\n");
+		goto out;
+	}
+
+	rc = admin_response(ocxlpmem);
+	if (rc < 0)
+		goto out;
+	if (rc != STATUS_SUCCESS) {
+		warn_status(ocxlpmem,
+			    "Unexpected status from controller stats", rc);
+		goto out;
+	}
+
+	rc = controller_stats_header_parse(ocxlpmem, &length);
+	if (rc)
+		goto out;
+
+	if (length != 0x140)
+		warn_status(ocxlpmem,
+			    "Unexpected length for controller stats data, expected 0x140, got 0x%x",
+			    length);
+
+	rc = ocxl_global_mmio_read64(ocxlpmem->ocxl_afu,
+				     ocxlpmem->admin_command.data_offset + 0x08 + 0x08,
+				     OCXL_LITTLE_ENDIAN, &val);
+	if (rc)
+		goto out;
+
+	args.reset_count = val >> 32;
+	args.reset_uptime = val & 0xFFFFFFFF;
+
+	rc = ocxl_global_mmio_read64(ocxlpmem->ocxl_afu,
+				     ocxlpmem->admin_command.data_offset + 0x08 + 0x10,
+				     OCXL_LITTLE_ENDIAN, &val);
+	if (rc)
+		goto out;
+
+	args.power_on_uptime = val >> 32;
+
+	rc = ocxl_global_mmio_read64(ocxlpmem->ocxl_afu,
+				     ocxlpmem->admin_command.data_offset + 0x08 + 0x40 + 0x08,
+				     OCXL_LITTLE_ENDIAN, &args.host_load_count);
+	if (rc)
+		goto out;
+
+	rc = ocxl_global_mmio_read64(ocxlpmem->ocxl_afu,
+				     ocxlpmem->admin_command.data_offset + 0x08 + 0x40 + 0x10,
+				     OCXL_LITTLE_ENDIAN, &args.host_store_count);
+	if (rc)
+		goto out;
+
+	rc = ocxl_global_mmio_read64(ocxlpmem->ocxl_afu,
+				     ocxlpmem->admin_command.data_offset + 0x08 + 0x40 + 0x18,
+				     OCXL_LITTLE_ENDIAN, &args.media_read_count);
+	if (rc)
+		goto out;
+
+	rc = ocxl_global_mmio_read64(ocxlpmem->ocxl_afu,
+				     ocxlpmem->admin_command.data_offset + 0x08 + 0x40 + 0x20,
+				     OCXL_LITTLE_ENDIAN, &args.media_write_count);
+	if (rc)
+		goto out;
+
+	rc = ocxl_global_mmio_read64(ocxlpmem->ocxl_afu,
+				     ocxlpmem->admin_command.data_offset + 0x08 + 0x40 + 0x28,
+				     OCXL_LITTLE_ENDIAN, &args.cache_hit_count);
+	if (rc)
+		goto out;
+
+	rc = ocxl_global_mmio_read64(ocxlpmem->ocxl_afu,
+				     ocxlpmem->admin_command.data_offset + 0x08 + 0x40 + 0x30,
+				     OCXL_LITTLE_ENDIAN, &args.cache_miss_count);
+	if (rc)
+		goto out;
+
+	rc = ocxl_global_mmio_read64(ocxlpmem->ocxl_afu,
+				     ocxlpmem->admin_command.data_offset + 0x08 + 0x40 + 0x38,
+				     OCXL_LITTLE_ENDIAN, &args.media_read_latency);
+	if (rc)
+		goto out;
+
+	rc = ocxl_global_mmio_read64(ocxlpmem->ocxl_afu,
+				     ocxlpmem->admin_command.data_offset + 0x08 + 0x40 + 0x40,
+				     OCXL_LITTLE_ENDIAN, &args.media_write_latency);
+	if (rc)
+		goto out;
+
+	rc = ocxl_global_mmio_read64(ocxlpmem->ocxl_afu,
+				     ocxlpmem->admin_command.data_offset + 0x08 + 0x40 + 0x48,
+				     OCXL_LITTLE_ENDIAN, &args.cache_read_latency);
+	if (rc)
+		goto out;
+
+	rc = ocxl_global_mmio_read64(ocxlpmem->ocxl_afu,
+				     ocxlpmem->admin_command.data_offset + 0x08 + 0x40 + 0x50,
+				     OCXL_LITTLE_ENDIAN, &args.cache_write_latency);
+	if (rc)
+		goto out;
+
+	if (copy_to_user(uarg, &args, sizeof(args))) {
+		rc = -EFAULT;
+		goto out;
+	}
+
+	rc = admin_response_handled(ocxlpmem);
+	if (rc)
+		goto out;
+
+	rc = 0;
+	goto out;
+
+out:
+	mutex_unlock(&ocxlpmem->admin_command.lock);
+	return rc;
+}
+
 static long file_ioctl(struct file *file, unsigned int cmd, unsigned long args)
 {
 	struct ocxlpmem *ocxlpmem = file->private_data;
@@ -781,6 +961,11 @@ static long file_ioctl(struct file *file, unsigned int cmd, unsigned long args)
 	case IOCTL_OCXL_PMEM_CONTROLLER_DUMP_COMPLETE:
 		rc = ioctl_controller_dump_complete(ocxlpmem);
 		break;
+
+	case IOCTL_OCXL_PMEM_CONTROLLER_STATS:
+		rc = ioctl_controller_stats(ocxlpmem,
+					    (struct ioctl_ocxl_pmem_controller_stats __user *)args);
+		break;
 	}
 
 	return rc;
diff --git a/include/uapi/nvdimm/ocxl-pmem.h b/include/uapi/nvdimm/ocxl-pmem.h
index d4d8512d03f7..add223aa2fdb 100644
--- a/include/uapi/nvdimm/ocxl-pmem.h
+++ b/include/uapi/nvdimm/ocxl-pmem.h
@@ -50,6 +50,22 @@ struct ioctl_ocxl_pmem_controller_dump_data {
 	__u64 reserved[8];
 };
 
+struct ioctl_ocxl_pmem_controller_stats {
+	__u32 reset_count;
+	__u32 reset_uptime; /* seconds */
+	__u32 power_on_uptime; /* seconds */
+	__u64 host_load_count;
+	__u64 host_store_count;
+	__u64 media_read_count;
+	__u64 media_write_count;
+	__u64 cache_hit_count;
+	__u64 cache_miss_count;
+	__u64 media_read_latency; /* nanoseconds */
+	__u64 media_write_latency; /* nanoseconds */
+	__u64 cache_read_latency; /* nanoseconds */
+	__u64 cache_write_latency; /* nanoseconds */
+};
+
 /* ioctl numbers */
 #define OCXL_PMEM_MAGIC 0x5C
 /* SCM devices */
@@ -57,5 +73,6 @@ struct ioctl_ocxl_pmem_controller_dump_data {
 #define IOCTL_OCXL_PMEM_CONTROLLER_DUMP			_IO(OCXL_PMEM_MAGIC, 0x02)
 #define IOCTL_OCXL_PMEM_CONTROLLER_DUMP_DATA		_IOWR(OCXL_PMEM_MAGIC, 0x03, struct ioctl_ocxl_pmem_controller_dump_data)
 #define IOCTL_OCXL_PMEM_CONTROLLER_DUMP_COMPLETE	_IO(OCXL_PMEM_MAGIC, 0x04)
+#define IOCTL_OCXL_PMEM_CONTROLLER_STATS		_IO(OCXL_PMEM_MAGIC, 0x05)
 
 #endif /* _UAPI_OCXL_SCM_H */
-- 
2.24.1