scsi: megaraid_sas: Export RAID map through debugfs

Create a debugfs interface for megaraid_sas driver.  Provide interface to
dump driver RAID map in debugfs.

Signed-off-by: Sumit Saxena <sumit.saxena@broadcom.com>
Signed-off-by: Shivasharan S <shivasharan.srikanteshwara@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/megaraid/Makefile

@@ -3,4 +3,4 @@ obj-$(CONFIG_MEGARAID_MM)	+= megaraid_mm.o
 obj-$(CONFIG_MEGARAID_MAILBOX)	+= megaraid_mbox.o
 obj-$(CONFIG_MEGARAID_SAS)	+= megaraid_sas.o
 megaraid_sas-objs := megaraid_sas_base.o megaraid_sas_fusion.o \
-	megaraid_sas_fp.o
+	megaraid_sas_fp.o megaraid_sas_debugfs.o

drivers/scsi/megaraid/megaraid_sas.h

@@ -2390,6 +2390,10 @@ struct megasas_instance {
 	u8 task_abort_tmo;
 	u8 max_reset_tmo;
 	u8 snapdump_wait_time;
+#ifdef CONFIG_DEBUG_FS
+	struct dentry *debugfs_root;
+	struct dentry *raidmap_dump;
+#endif
 	u8 enable_fw_dev_list;
 };
 struct MR_LD_VF_MAP {

drivers/scsi/megaraid/megaraid_sas_base.c

@@ -188,6 +188,12 @@ static bool support_nvme_encapsulation;
 /* define lock for aen poll */
 spinlock_t poll_aen_lock;
 
+extern struct dentry *megasas_debugfs_root;
+extern void megasas_init_debugfs(void);
+extern void megasas_exit_debugfs(void);
+extern void megasas_setup_debugfs(struct megasas_instance *instance);
+extern void megasas_destroy_debugfs(struct megasas_instance *instance);
+
 void
 megasas_complete_cmd(struct megasas_instance *instance, struct megasas_cmd *cmd,
 		     u8 alt_status);
@@ -7139,6 +7145,8 @@ static int megasas_probe_one(struct pci_dev *pdev,
 		goto fail_start_aen;
 	}
 
+	megasas_setup_debugfs(instance);
+
 	/* Get current SR-IOV LD/VF affiliation */
 	if (instance->requestorId)
 		megasas_get_ld_vf_affiliation(instance, 1);
@@ -7609,6 +7617,8 @@ static void megasas_detach_one(struct pci_dev *pdev)
 
 	megasas_free_ctrl_mem(instance);
 
+	megasas_destroy_debugfs(instance);
+
 	scsi_host_put(host);
 
 	pci_disable_device(pdev);
@@ -8536,6 +8546,8 @@ static int __init megasas_init(void)
 
 	megasas_mgmt_majorno = rval;
 
+	megasas_init_debugfs();
+
 	/*
 	 * Register ourselves as PCI hotplug module
 	 */
@@ -8595,6 +8607,7 @@ static int __init megasas_init(void)
 err_dcf_attr_ver:
 	pci_unregister_driver(&megasas_pci_driver);
 err_pcidrv:
+	megasas_exit_debugfs();
 	unregister_chrdev(megasas_mgmt_majorno, "megaraid_sas_ioctl");
 	return rval;
 }
@@ -8617,6 +8630,7 @@ static void __exit megasas_exit(void)
 			   &driver_attr_support_nvme_encapsulation);
 
 	pci_unregister_driver(&megasas_pci_driver);
+	megasas_exit_debugfs();
 	unregister_chrdev(megasas_mgmt_majorno, "megaraid_sas_ioctl");
 }
 

drivers/scsi/megaraid/megaraid_sas_debugfs.c

@@ -0,0 +1,180 @@
+/*
+ *  Linux MegaRAID driver for SAS based RAID controllers
+ *
+ *  Copyright (c) 2003-2018  LSI Corporation.
+ *  Copyright (c) 2003-2018  Avago Technologies.
+ *  Copyright (c) 2003-2018  Broadcom Inc.
+ *
+ *  This program is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU General Public License
+ *  as published by the Free Software Foundation; either version 2
+ *  of the License, or (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ *  Authors: Broadcom Inc.
+ *           Kashyap Desai <kashyap.desai@broadcom.com>
+ *           Sumit Saxena <sumit.saxena@broadcom.com>
+ *           Shivasharan S <shivasharan.srikanteshwara@broadcom.com>
+ *
+ *  Send feedback to: megaraidlinux.pdl@broadcom.com
+ */
+#include <linux/version.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/pci.h>
+#include <linux/interrupt.h>
+#include <linux/compat.h>
+#include <linux/irq_poll.h>
+
+#include <scsi/scsi.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_host.h>
+
+#include "megaraid_sas_fusion.h"
+#include "megaraid_sas.h"
+
+#ifdef CONFIG_DEBUG_FS
+#include <linux/debugfs.h>
+
+struct dentry *megasas_debugfs_root;
+
+static ssize_t
+megasas_debugfs_read(struct file *filp, char __user *ubuf, size_t cnt,
+		      loff_t *ppos)
+{
+	struct megasas_debugfs_buffer *debug = filp->private_data;
+
+	if (!debug || !debug->buf)
+		return 0;
+
+	return simple_read_from_buffer(ubuf, cnt, ppos, debug->buf, debug->len);
+}
+
+static int
+megasas_debugfs_raidmap_open(struct inode *inode, struct file *file)
+{
+	struct megasas_instance *instance = inode->i_private;
+	struct megasas_debugfs_buffer *debug;
+	struct fusion_context *fusion;
+
+	fusion = instance->ctrl_context;
+
+	debug = kzalloc(sizeof(struct megasas_debugfs_buffer), GFP_KERNEL);
+	if (!debug)
+		return -ENOMEM;
+
+	debug->buf = (void *)fusion->ld_drv_map[(instance->map_id & 1)];
+	debug->len = fusion->drv_map_sz;
+	file->private_data = debug;
+
+	return 0;
+}
+
+static int
+megasas_debugfs_release(struct inode *inode, struct file *file)
+{
+	struct megasas_debug_buffer *debug = file->private_data;
+
+	if (!debug)
+		return 0;
+
+	file->private_data = NULL;
+	kfree(debug);
+	return 0;
+}
+
+static const struct file_operations megasas_debugfs_raidmap_fops = {
+	.owner		= THIS_MODULE,
+	.open           = megasas_debugfs_raidmap_open,
+	.read           = megasas_debugfs_read,
+	.release        = megasas_debugfs_release,
+};
+
+/*
+ * megasas_init_debugfs :	Create debugfs root for megaraid_sas driver
+ */
+void megasas_init_debugfs(void)
+{
+	megasas_debugfs_root = debugfs_create_dir("megaraid_sas", NULL);
+	if (!megasas_debugfs_root)
+		pr_info("Cannot create debugfs root\n");
+}
+
+/*
+ * megasas_exit_debugfs :	Remove debugfs root for megaraid_sas driver
+ */
+void megasas_exit_debugfs(void)
+{
+	debugfs_remove_recursive(megasas_debugfs_root);
+}
+
+/*
+ * megasas_setup_debugfs :	Setup debugfs per Fusion adapter
+ * instance:				Soft instance of adapter
+ */
+void
+megasas_setup_debugfs(struct megasas_instance *instance)
+{
+	char name[64];
+	struct fusion_context *fusion;
+
+	fusion = instance->ctrl_context;
+
+	if (fusion) {
+		snprintf(name, sizeof(name),
+			 "scsi_host%d", instance->host->host_no);
+		if (!instance->debugfs_root) {
+			instance->debugfs_root =
+				debugfs_create_dir(name, megasas_debugfs_root);
+			if (!instance->debugfs_root) {
+				dev_err(&instance->pdev->dev,
+					"Cannot create per adapter debugfs directory\n");
+				return;
+			}
+		}
+
+		snprintf(name, sizeof(name), "raidmap_dump");
+		instance->raidmap_dump =
+			debugfs_create_file(name, S_IRUGO,
+					    instance->debugfs_root, instance,
+					    &megasas_debugfs_raidmap_fops);
+		if (!instance->raidmap_dump) {
+			dev_err(&instance->pdev->dev,
+				"Cannot create raidmap debugfs file\n");
+			debugfs_remove(instance->debugfs_root);
+			return;
+		}
+	}
+
+}
+
+/*
+ * megasas_destroy_debugfs :	Destroy debugfs per Fusion adapter
+ * instance:					Soft instance of adapter
+ */
+void megasas_destroy_debugfs(struct megasas_instance *instance)
+{
+	debugfs_remove_recursive(instance->debugfs_root);
+}
+
+#else
+void megasas_init_debugfs(void)
+{
+}
+void megasas_exit_debugfs(void)
+{
+}
+void megasas_setup_debugfs(struct megasas_instance *instance)
+{
+}
+void megasas_destroy_debugfs(struct megasas_instance *instance)
+{
+}
+#endif /*CONFIG_DEBUG_FS*/

drivers/scsi/megaraid/megaraid_sas_fusion.h

@@ -1360,6 +1360,11 @@ struct  MR_SNAPDUMP_PROPERTIES {
 	u8       reserved[12];
 };
 
+struct megasas_debugfs_buffer {
+	void *buf;
+	u32 len;
+};
+
 void megasas_free_cmds_fusion(struct megasas_instance *instance);
 int megasas_ioc_init_fusion(struct megasas_instance *instance);
 u8 megasas_get_map_info(struct megasas_instance *instance);