mtip32xx: Add debugfs entry device_status

This patch adds a new debugfs entry 'device_status' in
/sys/kernel/debug/rssd. The value of this entry shows
devices online and those in the process of removing.
Signed-off-by: Sam Bradshaw <sbradshaw@micron.com>
Signed-off-by: Asai Thambi S P <asamymuthupa@micron.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/block/mtip32xx/mtip32xx.c

@@ -81,12 +81,17 @@
 /* Device instance number, incremented each time a device is probed. */
 static int instance;
 
+struct list_head online_list;
+struct list_head removing_list;
+spinlock_t dev_lock;
+
 /*
  * Global variable used to hold the major block device number
  * allocated in mtip_init().
  */
 static int mtip_major;
 static struct dentry *dfs_parent;
+static struct dentry *dfs_device_status;
 
 static u32 cpu_use[NR_CPUS];
 
@@ -2707,6 +2712,100 @@ static ssize_t mtip_hw_show_status(struct device *dev,
 
 static DEVICE_ATTR(status, S_IRUGO, mtip_hw_show_status, NULL);
 
+/* debugsfs entries */
+
+static ssize_t show_device_status(struct device_driver *drv, char *buf)
+{
+	int size = 0;
+	struct driver_data *dd, *tmp;
+	unsigned long flags;
+	char id_buf[42];
+	u16 status = 0;
+
+	spin_lock_irqsave(&dev_lock, flags);
+	size += sprintf(&buf[size], "Devices Present:\n");
+	list_for_each_entry_safe(dd, tmp, &online_list, online_list) {
+		if (dd && dd->pdev) {
+			if (dd->port &&
+			    dd->port->identify &&
+			    dd->port->identify_valid) {
+				strlcpy(id_buf,
+					(char *) (dd->port->identify + 10), 21);
+				status = *(dd->port->identify + 141);
+			} else {
+				memset(id_buf, 0, 42);
+				status = 0;
+			}
+
+			if (dd->port &&
+			    test_bit(MTIP_PF_REBUILD_BIT, &dd->port->flags)) {
+				size += sprintf(&buf[size],
+					" device %s %s (ftl rebuild %d %%)\n",
+					dev_name(&dd->pdev->dev),
+					id_buf,
+					status);
+			} else {
+				size += sprintf(&buf[size],
+					" device %s %s\n",
+					dev_name(&dd->pdev->dev),
+					id_buf);
+			}
+		}
+	}
+
+	size += sprintf(&buf[size], "Devices Being Removed:\n");
+	list_for_each_entry_safe(dd, tmp, &removing_list, remove_list) {
+		if (dd && dd->pdev) {
+			if (dd->port &&
+			    dd->port->identify &&
+			    dd->port->identify_valid) {
+				strlcpy(id_buf,
+					(char *) (dd->port->identify+10), 21);
+				status = *(dd->port->identify + 141);
+			} else {
+				memset(id_buf, 0, 42);
+				status = 0;
+			}
+
+			if (dd->port &&
+			    test_bit(MTIP_PF_REBUILD_BIT, &dd->port->flags)) {
+				size += sprintf(&buf[size],
+					" device %s %s (ftl rebuild %d %%)\n",
+					dev_name(&dd->pdev->dev),
+					id_buf,
+					status);
+			} else {
+				size += sprintf(&buf[size],
+					" device %s %s\n",
+					dev_name(&dd->pdev->dev),
+					id_buf);
+			}
+		}
+	}
+	spin_unlock_irqrestore(&dev_lock, flags);
+
+	return size;
+}
+
+static ssize_t mtip_hw_read_device_status(struct file *f, char __user *ubuf,
+						size_t len, loff_t *offset)
+{
+	int size = *offset;
+	char buf[MTIP_DFS_MAX_BUF_SIZE];
+
+	if (!len || *offset)
+		return 0;
+
+	size += show_device_status(NULL, buf);
+
+	*offset = size <= len ? size : len;
+	size = copy_to_user(ubuf, buf, *offset);
+	if (size)
+		return -EFAULT;
+
+	return *offset;
+}
+
 static ssize_t mtip_hw_read_registers(struct file *f, char __user *ubuf,
 				  size_t len, loff_t *offset)
 {
@@ -2801,6 +2900,13 @@ static ssize_t mtip_hw_read_flags(struct file *f, char __user *ubuf,
 	return *offset;
 }
 
+static const struct file_operations mtip_device_status_fops = {
+	.owner  = THIS_MODULE,
+	.open   = simple_open,
+	.read   = mtip_hw_read_device_status,
+	.llseek = no_llseek,
+};
+
 static const struct file_operations mtip_regs_fops = {
 	.owner  = THIS_MODULE,
 	.open   = simple_open,
@@ -4158,6 +4264,7 @@ static int mtip_pci_probe(struct pci_dev *pdev,
 	const struct cpumask *node_mask;
 	int cpu, i = 0, j = 0;
 	int my_node = NUMA_NO_NODE;
+	unsigned long flags;
 
 	/* Allocate memory for this devices private data. */
 	my_node = pcibus_to_node(pdev->bus);
@@ -4215,6 +4322,9 @@ static int mtip_pci_probe(struct pci_dev *pdev,
 	dd->pdev	= pdev;
 	dd->numa_node	= my_node;
 
+	INIT_LIST_HEAD(&dd->online_list);
+	INIT_LIST_HEAD(&dd->remove_list);
+
 	memset(dd->workq_name, 0, 32);
 	snprintf(dd->workq_name, 31, "mtipq%d", dd->instance);
 
@@ -4304,6 +4414,12 @@ static int mtip_pci_probe(struct pci_dev *pdev,
 		set_bit(MTIP_DDF_INIT_DONE_BIT, &dd->dd_flag);
 	else
 		rv = 0; /* device in rebuild state, return 0 from probe */
+
+	/* Add to online list even if in ftl rebuild */
+	spin_lock_irqsave(&dev_lock, flags);
+	list_add(&dd->online_list, &online_list);
+	spin_unlock_irqrestore(&dev_lock, flags);
+
 	goto done;
 
 block_initialize_err:
@@ -4337,9 +4453,15 @@ static void mtip_pci_remove(struct pci_dev *pdev)
 {
 	struct driver_data *dd = pci_get_drvdata(pdev);
 	int counter = 0;
+	unsigned long flags;
 
 	set_bit(MTIP_DDF_REMOVE_PENDING_BIT, &dd->dd_flag);
 
+	spin_lock_irqsave(&dev_lock, flags);
+	list_del_init(&dd->online_list);
+	list_add(&dd->remove_list, &removing_list);
+	spin_unlock_irqrestore(&dev_lock, flags);
+
 	if (mtip_check_surprise_removal(pdev)) {
 		while (!test_bit(MTIP_DDF_CLEANUP_BIT, &dd->dd_flag)) {
 			counter++;
@@ -4365,6 +4487,10 @@ static void mtip_pci_remove(struct pci_dev *pdev)
 
 	pci_disable_msi(pdev);
 
+	spin_lock_irqsave(&dev_lock, flags);
+	list_del_init(&dd->remove_list);
+	spin_unlock_irqrestore(&dev_lock, flags);
+
 	kfree(dd);
 	pcim_iounmap_regions(pdev, 1 << MTIP_ABAR);
 }
@@ -4512,6 +4638,11 @@ static int __init mtip_init(void)
 
 	pr_info(MTIP_DRV_NAME " Version " MTIP_DRV_VERSION "\n");
 
+	spin_lock_init(&dev_lock);
+
+	INIT_LIST_HEAD(&online_list);
+	INIT_LIST_HEAD(&removing_list);
+
 	/* Allocate a major block device number to use with this driver. */
 	error = register_blkdev(0, MTIP_DRV_NAME);
 	if (error <= 0) {
@@ -4521,12 +4652,19 @@ static int __init mtip_init(void)
 	}
 	mtip_major = error;
 
-	if (!dfs_parent) {
 	dfs_parent = debugfs_create_dir("rssd", NULL);
 	if (IS_ERR_OR_NULL(dfs_parent)) {
 		pr_warn("Error creating debugfs parent\n");
 		dfs_parent = NULL;
 	}
+	if (dfs_parent) {
+		dfs_device_status = debugfs_create_file("device_status",
+					S_IRUGO, dfs_parent, NULL,
+					&mtip_device_status_fops);
+		if (IS_ERR_OR_NULL(dfs_device_status)) {
+			pr_err("Error creating device_status node\n");
+			dfs_device_status = NULL;
+		}
 	}
 
 	/* Register our PCI operations. */

drivers/block/mtip32xx/mtip32xx.h

@@ -129,9 +129,9 @@ enum {
 	MTIP_PF_EH_ACTIVE_BIT       = 1, /* error handling */
 	MTIP_PF_SE_ACTIVE_BIT       = 2, /* secure erase */
 	MTIP_PF_DM_ACTIVE_BIT       = 3, /* download microcde */
-	MTIP_PF_PAUSE_IO      =	((1 << MTIP_PF_IC_ACTIVE_BIT) | \
-				(1 << MTIP_PF_EH_ACTIVE_BIT) | \
-				(1 << MTIP_PF_SE_ACTIVE_BIT) | \
+	MTIP_PF_PAUSE_IO      =	((1 << MTIP_PF_IC_ACTIVE_BIT) |
+				(1 << MTIP_PF_EH_ACTIVE_BIT) |
+				(1 << MTIP_PF_SE_ACTIVE_BIT) |
 				(1 << MTIP_PF_DM_ACTIVE_BIT)),
 
 	MTIP_PF_SVC_THD_ACTIVE_BIT  = 4,
@@ -144,9 +144,9 @@ enum {
 	MTIP_DDF_REMOVE_PENDING_BIT = 1,
 	MTIP_DDF_OVER_TEMP_BIT      = 2,
 	MTIP_DDF_WRITE_PROTECT_BIT  = 3,
-	MTIP_DDF_STOP_IO      = ((1 << MTIP_DDF_REMOVE_PENDING_BIT) | \
-				(1 << MTIP_DDF_SEC_LOCK_BIT) | \
-				(1 << MTIP_DDF_OVER_TEMP_BIT) | \
+	MTIP_DDF_STOP_IO      = ((1 << MTIP_DDF_REMOVE_PENDING_BIT) |
+				(1 << MTIP_DDF_SEC_LOCK_BIT) |
+				(1 << MTIP_DDF_OVER_TEMP_BIT) |
 				(1 << MTIP_DDF_WRITE_PROTECT_BIT)),
 
 	MTIP_DDF_CLEANUP_BIT        = 5,
@@ -501,6 +501,10 @@ struct driver_data {
 	atomic_t irq_workers_active;
 
 	int isr_binding;
+
+	struct list_head online_list; /* linkage for online list */
+
+	struct list_head remove_list; /* linkage for removing list */
 };
 
 #endif