1 files changed, 282 insertions, 165 deletions

diff --git a/drivers/ntb/test/ntb_pingpong.c b/drivers/ntb/test/ntb_pingpong.c
index e700873e03fb..65865e460ab8 100644
--- a/drivers/ntb/test/ntb_pingpong.c
+++ b/drivers/ntb/test/ntb_pingpong.c
@@ -1,10 +1,11 @@
 /*
- * This file is provided under a dual BSD/GPLv2 license.  When using or
+ *   This file is provided under a dual BSD/GPLv2 license.  When using or
  *   redistributing this file, you may do so under either license.
  *
  *   GPL LICENSE SUMMARY
  *
  *   Copyright (C) 2015 EMC Corporation. All Rights Reserved.
+ *   Copyright (C) 2017 T-Platforms. All Rights Reserved.
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of version 2 of the GNU General Public License as
@@ -18,6 +19,7 @@
  *   BSD LICENSE
  *
  *   Copyright (C) 2015 EMC Corporation. All Rights Reserved.
+ *   Copyright (C) 2017 T-Platforms. All Rights Reserved.
  *
  *   Redistribution and use in source and binary forms, with or without
  *   modification, are permitted provided that the following conditions
@@ -46,36 +48,45 @@
  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  * PCIe NTB Pingpong Linux driver
- *
- * Contact Information:
- * Allen Hubbe <Allen.Hubbe@emc.com>
  */
 
-/* Note: load this module with option 'dyndbg=+p' */
+/*
+ * How to use this tool, by example.
+ *
+ * Assuming $DBG_DIR is something like:
+ * '/sys/kernel/debug/ntb_perf/0000:00:03.0'
+ * Suppose aside from local device there is at least one remote device
+ * connected to NTB with index 0.
+ *-----------------------------------------------------------------------------
+ * Eg: install driver with specified delay between doorbell event and response
+ *
+ * root@self# insmod ntb_pingpong.ko delay_ms=1000
+ *-----------------------------------------------------------------------------
+ * Eg: get number of ping-pong cycles performed
+ *
+ * root@self# cat $DBG_DIR/count
+ */
 
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/device.h>
+#include <linux/bitops.h>
 
-#include <linux/dma-mapping.h>
 #include <linux/pci.h>
 #include <linux/slab.h>
-#include <linux/spinlock.h>
+#include <linux/hrtimer.h>
 #include <linux/debugfs.h>
 
 #include <linux/ntb.h>
 
-#define DRIVER_NAME			"ntb_pingpong"
-#define DRIVER_DESCRIPTION		"PCIe NTB Simple Pingpong Client"
-
-#define DRIVER_VERSION			"1.0"
-#define DRIVER_RELDATE			"24 March 2015"
-#define DRIVER_AUTHOR			"Allen Hubbe <Allen.Hubbe@emc.com>"
+#define DRIVER_NAME		"ntb_pingpong"
+#define DRIVER_VERSION		"2.0"
 
 MODULE_LICENSE("Dual BSD/GPL");
 MODULE_VERSION(DRIVER_VERSION);
-MODULE_AUTHOR(DRIVER_AUTHOR);
-MODULE_DESCRIPTION(DRIVER_DESCRIPTION);
+MODULE_AUTHOR("Allen Hubbe <Allen.Hubbe@emc.com>");
+MODULE_DESCRIPTION("PCIe NTB Simple Pingpong Client");
 
 static unsigned int unsafe;
 module_param(unsafe, uint, 0644);
@@ -85,237 +96,343 @@ static unsigned int delay_ms = 1000;
 module_param(delay_ms, uint, 0644);
 MODULE_PARM_DESC(delay_ms, "Milliseconds to delay the response to peer");
 
-static unsigned long db_init = 0x7;
-module_param(db_init, ulong, 0644);
-MODULE_PARM_DESC(db_init, "Initial doorbell bits to ring on the peer");
-
-/* Only two-ports NTB devices are supported */
-#define PIDX		NTB_DEF_PEER_IDX
-
 struct pp_ctx {
-	struct ntb_dev			*ntb;
-	u64				db_bits;
-	/* synchronize access to db_bits by ping and pong */
-	spinlock_t			db_lock;
-	struct timer_list		db_timer;
-	unsigned long			db_delay;
-	struct dentry			*debugfs_node_dir;
-	struct dentry			*debugfs_count;
-	atomic_t			count;
+	struct ntb_dev *ntb;
+	struct hrtimer timer;
+	u64 in_db;
+	u64 out_db;
+	int out_pidx;
+	u64 nmask;
+	u64 pmask;
+	atomic_t count;
+	spinlock_t lock;
+	struct dentry *dbgfs_dir;
 };
+#define to_pp_timer(__timer) \
+	container_of(__timer, struct pp_ctx, timer)
 
-static struct dentry *pp_debugfs_dir;
+static struct dentry *pp_dbgfs_topdir;
 
-static void pp_ping(struct timer_list *t)
+static int pp_find_next_peer(struct pp_ctx *pp)
 {
-	struct pp_ctx *pp = from_timer(pp, t, db_timer);
-	unsigned long irqflags;
-	u64 db_bits, db_mask;
-	u32 spad_rd, spad_wr;
+	u64 link, out_db;
+	int pidx;
+
+	link = ntb_link_is_up(pp->ntb, NULL, NULL);
+
+	/* Find next available peer */
+	if (link & pp->nmask) {
+		pidx = __ffs64(link & pp->nmask);
+		out_db = BIT_ULL(pidx + 1);
+	} else if (link & pp->pmask) {
+		pidx = __ffs64(link & pp->pmask);
+		out_db = BIT_ULL(pidx);
+	} else {
+		return -ENODEV;
+	}
 
-	spin_lock_irqsave(&pp->db_lock, irqflags);
-	{
-		db_mask = ntb_db_valid_mask(pp->ntb);
-		db_bits = ntb_db_read(pp->ntb);
+	spin_lock(&pp->lock);
+	pp->out_pidx = pidx;
+	pp->out_db = out_db;
+	spin_unlock(&pp->lock);
 
-		if (db_bits) {
-			dev_dbg(&pp->ntb->dev,
-				"Masked pongs %#llx\n",
-				db_bits);
-			ntb_db_clear(pp->ntb, db_bits);
-		}
+	return 0;
+}
 
-		db_bits = ((pp->db_bits | db_bits) << 1) & db_mask;
+static void pp_setup(struct pp_ctx *pp)
+{
+	int ret;
 
-		if (!db_bits)
-			db_bits = db_init;
+	ntb_db_set_mask(pp->ntb, pp->in_db);
 
-		spad_rd = ntb_spad_read(pp->ntb, 0);
-		spad_wr = spad_rd + 1;
+	hrtimer_cancel(&pp->timer);
 
-		dev_dbg(&pp->ntb->dev,
-			"Ping bits %#llx read %#x write %#x\n",
-			db_bits, spad_rd, spad_wr);
+	ret = pp_find_next_peer(pp);
+	if (ret == -ENODEV) {
+		dev_dbg(&pp->ntb->dev, "Got no peers, so cancel\n");
+		return;
+	}
 
-		ntb_peer_spad_write(pp->ntb, PIDX, 0, spad_wr);
-		ntb_peer_db_set(pp->ntb, db_bits);
-		ntb_db_clear_mask(pp->ntb, db_mask);
+	dev_dbg(&pp->ntb->dev, "Ping-pong started with port %d, db %#llx\n",
+		ntb_peer_port_number(pp->ntb, pp->out_pidx), pp->out_db);
 
-		pp->db_bits = 0;
-	}
-	spin_unlock_irqrestore(&pp->db_lock, irqflags);
+	hrtimer_start(&pp->timer, ms_to_ktime(delay_ms), HRTIMER_MODE_REL);
 }
 
-static void pp_link_event(void *ctx)
+static void pp_clear(struct pp_ctx *pp)
 {
-	struct pp_ctx *pp = ctx;
+	hrtimer_cancel(&pp->timer);
 
-	if (ntb_link_is_up(pp->ntb, NULL, NULL) == 1) {
-		dev_dbg(&pp->ntb->dev, "link is up\n");
-		pp_ping(&pp->db_timer);
-	} else {
-		dev_dbg(&pp->ntb->dev, "link is down\n");
-		del_timer(&pp->db_timer);
-	}
+	ntb_db_set_mask(pp->ntb, pp->in_db);
+
+	dev_dbg(&pp->ntb->dev, "Ping-pong cancelled\n");
 }
 
-static void pp_db_event(void *ctx, int vec)
+static void pp_ping(struct pp_ctx *pp)
 {
-	struct pp_ctx *pp = ctx;
-	u64 db_bits, db_mask;
-	unsigned long irqflags;
+	u32 count;
 
-	spin_lock_irqsave(&pp->db_lock, irqflags);
-	{
-		db_mask = ntb_db_vector_mask(pp->ntb, vec);
-		db_bits = db_mask & ntb_db_read(pp->ntb);
-		ntb_db_set_mask(pp->ntb, db_mask);
-		ntb_db_clear(pp->ntb, db_bits);
+	count = atomic_read(&pp->count);
 
-		pp->db_bits |= db_bits;
+	spin_lock(&pp->lock);
+	ntb_peer_spad_write(pp->ntb, pp->out_pidx, 0, count);
+	ntb_peer_msg_write(pp->ntb, pp->out_pidx, 0, count);
 
-		mod_timer(&pp->db_timer, jiffies + pp->db_delay);
+	dev_dbg(&pp->ntb->dev, "Ping port %d spad %#x, msg %#x\n",
+		ntb_peer_port_number(pp->ntb, pp->out_pidx), count, count);
 
-		dev_dbg(&pp->ntb->dev,
-			"Pong vec %d bits %#llx\n",
-			vec, db_bits);
-		atomic_inc(&pp->count);
-	}
-	spin_unlock_irqrestore(&pp->db_lock, irqflags);
+	ntb_peer_db_set(pp->ntb, pp->out_db);
+	ntb_db_clear_mask(pp->ntb, pp->in_db);
+	spin_unlock(&pp->lock);
 }
 
-static int pp_debugfs_setup(struct pp_ctx *pp)
+static void pp_pong(struct pp_ctx *pp)
 {
-	struct pci_dev *pdev = pp->ntb->pdev;
+	u32 msg_data = -1, spad_data = -1;
+	int pidx = 0;
 
-	if (!pp_debugfs_dir)
-		return -ENODEV;
+	/* Read pong data */
+	spad_data = ntb_spad_read(pp->ntb, 0);
+	msg_data = ntb_msg_read(pp->ntb, &pidx, 0);
+	ntb_msg_clear_sts(pp->ntb, -1);
 
-	pp->debugfs_node_dir = debugfs_create_dir(pci_name(pdev),
-						  pp_debugfs_dir);
-	if (!pp->debugfs_node_dir)
-		return -ENODEV;
+	/*
+	 * Scratchpad and message data may differ, since message register can't
+	 * be rewritten unless status is cleared. Additionally either of them
+	 * might be unsupported
+	 */
+	dev_dbg(&pp->ntb->dev, "Pong spad %#x, msg %#x (port %d)\n",
+		spad_data, msg_data, ntb_peer_port_number(pp->ntb, pidx));
 
-	pp->debugfs_count = debugfs_create_atomic_t("count", S_IRUSR | S_IWUSR,
-						    pp->debugfs_node_dir,
-						    &pp->count);
-	if (!pp->debugfs_count)
-		return -ENODEV;
+	atomic_inc(&pp->count);
 
-	return 0;
+	ntb_db_set_mask(pp->ntb, pp->in_db);
+	ntb_db_clear(pp->ntb, pp->in_db);
+
+	hrtimer_start(&pp->timer, ms_to_ktime(delay_ms), HRTIMER_MODE_REL);
+}
+
+static enum hrtimer_restart pp_timer_func(struct hrtimer *t)
+{
+	struct pp_ctx *pp = to_pp_timer(t);
+
+	pp_ping(pp);
+
+	return HRTIMER_NORESTART;
+}
+
+static void pp_link_event(void *ctx)
+{
+	struct pp_ctx *pp = ctx;
+
+	pp_setup(pp);
+}
+
+static void pp_db_event(void *ctx, int vec)
+{
+	struct pp_ctx *pp = ctx;
+
+	pp_pong(pp);
 }
 
 static const struct ntb_ctx_ops pp_ops = {
 	.link_event = pp_link_event,
-	.db_event = pp_db_event,
+	.db_event = pp_db_event
 };
 
-static int pp_probe(struct ntb_client *client,
-		    struct ntb_dev *ntb)
+static int pp_check_ntb(struct ntb_dev *ntb)
 {
-	struct pp_ctx *pp;
-	int rc;
+	u64 pmask;
 
 	if (ntb_db_is_unsafe(ntb)) {
-		dev_dbg(&ntb->dev, "doorbell is unsafe\n");
-		if (!unsafe) {
-			rc = -EINVAL;
-			goto err_pp;
-		}
-	}
-
-	if (ntb_spad_count(ntb) < 1) {
-		dev_dbg(&ntb->dev, "no enough scratchpads\n");
-		rc = -EINVAL;
-		goto err_pp;
+		dev_dbg(&ntb->dev, "Doorbell is unsafe\n");
+		if (!unsafe)
+			return -EINVAL;
 	}
 
 	if (ntb_spad_is_unsafe(ntb)) {
-		dev_dbg(&ntb->dev, "scratchpad is unsafe\n");
-		if (!unsafe) {
-			rc = -EINVAL;
-			goto err_pp;
-		}
+		dev_dbg(&ntb->dev, "Scratchpad is unsafe\n");
+		if (!unsafe)
+			return -EINVAL;
 	}
 
-	if (ntb_peer_port_count(ntb) != NTB_DEF_PEER_CNT)
-		dev_warn(&ntb->dev, "multi-port NTB is unsupported\n");
+	pmask = GENMASK_ULL(ntb_peer_port_count(ntb), 0);
+	if ((ntb_db_valid_mask(ntb) & pmask) != pmask) {
+		dev_err(&ntb->dev, "Unsupported DB configuration\n");
+		return -EINVAL;
+	}
 
-	pp = kmalloc(sizeof(*pp), GFP_KERNEL);
-	if (!pp) {
-		rc = -ENOMEM;
-		goto err_pp;
+	if (ntb_spad_count(ntb) < 1 && ntb_msg_count(ntb) < 1) {
+		dev_err(&ntb->dev, "Scratchpads and messages unsupported\n");
+		return -EINVAL;
+	} else if (ntb_spad_count(ntb) < 1) {
+		dev_dbg(&ntb->dev, "Scratchpads unsupported\n");
+	} else if (ntb_msg_count(ntb) < 1) {
+		dev_dbg(&ntb->dev, "Messages unsupported\n");
 	}
 
+	return 0;
+}
+
+static struct pp_ctx *pp_create_data(struct ntb_dev *ntb)
+{
+	struct pp_ctx *pp;
+
+	pp = devm_kzalloc(&ntb->dev, sizeof(*pp), GFP_KERNEL);
+	if (!pp)
+		return ERR_PTR(-ENOMEM);
+
 	pp->ntb = ntb;
-	pp->db_bits = 0;
 	atomic_set(&pp->count, 0);
-	spin_lock_init(&pp->db_lock);
-	timer_setup(&pp->db_timer, pp_ping, 0);
-	pp->db_delay = msecs_to_jiffies(delay_ms);
+	spin_lock_init(&pp->lock);
+	hrtimer_init(&pp->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	pp->timer.function = pp_timer_func;
+
+	return pp;
+}
+
+static void pp_init_flds(struct pp_ctx *pp)
+{
+	int pidx, lport, pcnt;
+
+	/* Find global port index */
+	lport = ntb_port_number(pp->ntb);
+	pcnt = ntb_peer_port_count(pp->ntb);
+	for (pidx = 0; pidx < pcnt; pidx++) {
+		if (lport < ntb_peer_port_number(pp->ntb, pidx))
+			break;
+	}
 
-	rc = ntb_set_ctx(ntb, pp, &pp_ops);
-	if (rc)
-		goto err_ctx;
+	pp->in_db = BIT_ULL(pidx);
+	pp->pmask = GENMASK_ULL(pidx, 0) >> 1;
+	pp->nmask = GENMASK_ULL(pcnt - 1, pidx);
 
-	rc = pp_debugfs_setup(pp);
-	if (rc)
-		goto err_ctx;
+	dev_dbg(&pp->ntb->dev, "Inbound db %#llx, prev %#llx, next %#llx\n",
+		pp->in_db, pp->pmask, pp->nmask);
+}
+
+static int pp_mask_events(struct pp_ctx *pp)
+{
+	u64 db_mask, msg_mask;
+	int ret;
+
+	db_mask = ntb_db_valid_mask(pp->ntb);
+	ret = ntb_db_set_mask(pp->ntb, db_mask);
+	if (ret)
+		return ret;
 
-	ntb_link_enable(ntb, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
-	ntb_link_event(ntb);
+	/* Skip message events masking if unsupported */
+	if (ntb_msg_count(pp->ntb) < 1)
+		return 0;
+
+	msg_mask = ntb_msg_outbits(pp->ntb) | ntb_msg_inbits(pp->ntb);
+	return ntb_msg_set_mask(pp->ntb, msg_mask);
+}
+
+static int pp_setup_ctx(struct pp_ctx *pp)
+{
+	int ret;
+
+	ret = ntb_set_ctx(pp->ntb, pp, &pp_ops);
+	if (ret)
+		return ret;
+
+	ntb_link_enable(pp->ntb, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
+	/* Might be not necessary */
+	ntb_link_event(pp->ntb);
 
 	return 0;
+}
+
+static void pp_clear_ctx(struct pp_ctx *pp)
+{
+	ntb_link_disable(pp->ntb);
 
-err_ctx:
-	kfree(pp);
-err_pp:
-	return rc;
+	ntb_clear_ctx(pp->ntb);
 }
 
-static void pp_remove(struct ntb_client *client,
-		      struct ntb_dev *ntb)
+static void pp_setup_dbgfs(struct pp_ctx *pp)
+{
+	struct pci_dev *pdev = pp->ntb->pdev;
+	void *ret;
+
+	pp->dbgfs_dir = debugfs_create_dir(pci_name(pdev), pp_dbgfs_topdir);
+
+	ret = debugfs_create_atomic_t("count", 0600, pp->dbgfs_dir, &pp->count);
+	if (!ret)
+		dev_warn(&pp->ntb->dev, "DebugFS unsupported\n");
+}
+
+static void pp_clear_dbgfs(struct pp_ctx *pp)
+{
+	debugfs_remove_recursive(pp->dbgfs_dir);
+}
+
+static int pp_probe(struct ntb_client *client, struct ntb_dev *ntb)
+{
+	struct pp_ctx *pp;
+	int ret;
+
+	ret = pp_check_ntb(ntb);
+	if (ret)
+		return ret;
+
+	pp = pp_create_data(ntb);
+	if (IS_ERR(pp))
+		return PTR_ERR(pp);
+
+	pp_init_flds(pp);
+
+	ret = pp_mask_events(pp);
+	if (ret)
+		return ret;
+
+	ret = pp_setup_ctx(pp);
+	if (ret)
+		return ret;
+
+	pp_setup_dbgfs(pp);
+
+	return 0;
+}
+
+static void pp_remove(struct ntb_client *client, struct ntb_dev *ntb)
 {
 	struct pp_ctx *pp = ntb->ctx;
 
-	debugfs_remove_recursive(pp->debugfs_node_dir);
+	pp_clear_dbgfs(pp);
 
-	ntb_clear_ctx(ntb);
-	del_timer_sync(&pp->db_timer);
-	ntb_link_disable(ntb);
+	pp_clear_ctx(pp);
 
-	kfree(pp);
+	pp_clear(pp);
 }
 
 static struct ntb_client pp_client = {
 	.ops = {
 		.probe = pp_probe,
-		.remove = pp_remove,
-	},
+		.remove = pp_remove
+	}
 };
 
 static int __init pp_init(void)
 {
-	int rc;
+	int ret;
 
 	if (debugfs_initialized())
-		pp_debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
+		pp_dbgfs_topdir = debugfs_create_dir(KBUILD_MODNAME, NULL);
 
-	rc = ntb_register_client(&pp_client);
-	if (rc)
-		goto err_client;
+	ret = ntb_register_client(&pp_client);
+	if (ret)
+		debugfs_remove_recursive(pp_dbgfs_topdir);
 
-	return 0;
-
-err_client:
-	debugfs_remove_recursive(pp_debugfs_dir);
-	return rc;
+	return ret;
 }
 module_init(pp_init);
 
 static void __exit pp_exit(void)
 {
 	ntb_unregister_client(&pp_client);
-	debugfs_remove_recursive(pp_debugfs_dir);
+	debugfs_remove_recursive(pp_dbgfs_topdir);
 }
 module_exit(pp_exit);
+