RDMA/hns: Enable all CMDQ context

Fix error of cmd's context number calculation algorithm to enable all of
32 cmd entries and support 32 concurrent accesses.

Link: https://lore.kernel.org/r/1617262341-37571-2-git-send-email-liweihang@huawei.com
Signed-off-by: Lang Cheng <chenglang@huawei.com>
Signed-off-by: Weihang Li <liweihang@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/hw/hns/hns_roce_cmd.c

@@ -38,22 +38,14 @@
 
 #define CMD_POLL_TOKEN 0xffff
 #define CMD_MAX_NUM 32
-#define CMD_TOKEN_MASK 0x1f
 
 static int hns_roce_cmd_mbox_post_hw(struct hns_roce_dev *hr_dev, u64 in_param,
 				     u64 out_param, u32 in_modifier,
 				     u8 op_modifier, u16 op, u16 token,
 				     int event)
 {
-	struct hns_roce_cmdq *cmd = &hr_dev->cmd;
-	int ret;
-
-	mutex_lock(&cmd->hcr_mutex);
-	ret = hr_dev->hw->post_mbox(hr_dev, in_param, out_param, in_modifier,
-				    op_modifier, op, token, event);
-	mutex_unlock(&cmd->hcr_mutex);
-
-	return ret;
+	return hr_dev->hw->post_mbox(hr_dev, in_param, out_param, in_modifier,
+				     op_modifier, op, token, event);
 }
 
 /* this should be called with "poll_sem" */
@@ -96,15 +88,18 @@ void hns_roce_cmd_event(struct hns_roce_dev *hr_dev, u16 token, u8 status,
 	struct hns_roce_cmd_context *context =
 		&hr_dev->cmd.context[token % hr_dev->cmd.max_cmds];
 
-	if (token != context->token)
+	if (unlikely(token != context->token)) {
+		dev_err_ratelimited(hr_dev->dev,
+				    "[cmd] invalid ae token %x,context token is %x!\n",
+				    token, context->token);
 		return;
+	}
 
 	context->result = (status == HNS_ROCE_CMD_SUCCESS) ? 0 : (-EIO);
 	context->out_param = out_param;
 	complete(&context->done);
 }
 
-/* this should be called with "use_events" */
 static int __hns_roce_cmd_mbox_wait(struct hns_roce_dev *hr_dev, u64 in_param,
 				    u64 out_param, unsigned long in_modifier,
 				    u8 op_modifier, u16 op,
@@ -116,44 +111,38 @@ static int __hns_roce_cmd_mbox_wait(struct hns_roce_dev *hr_dev, u64 in_param,
 	int ret;
 
 	spin_lock(&cmd->context_lock);
-	WARN_ON(cmd->free_head < 0);
-	context = &cmd->context[cmd->free_head];
-	context->token += cmd->token_mask + 1;
-	cmd->free_head = context->next;
+
+	do {
+		context = &cmd->context[cmd->free_head];
+		cmd->free_head = context->next;
+	} while (context->busy);
+
+	context->busy = 1;
+	context->token += cmd->max_cmds;
+
 	spin_unlock(&cmd->context_lock);
 
-	init_completion(&context->done);
+	reinit_completion(&context->done);
 
 	ret = hns_roce_cmd_mbox_post_hw(hr_dev, in_param, out_param,
 					in_modifier, op_modifier, op,
 					context->token, 1);
 	if (ret)
 		goto out;
 
-	/*
-	 * It is timeout when wait_for_completion_timeout return 0
-	 * The return value is the time limit set in advance
-	 * how many seconds showing
-	 */
 	if (!wait_for_completion_timeout(&context->done,
 					 msecs_to_jiffies(timeout))) {
-		dev_err(dev, "[cmd]wait_for_completion_timeout timeout\n");
+		dev_err(dev, "[cmd] token %x timeout, drop.\n", context->token);
 		ret = -EBUSY;
 		goto out;
 	}
 
 	ret = context->result;
-	if (ret) {
-		dev_err(dev, "[cmd]event mod cmd process error!err=%d\n", ret);
-		goto out;
-	}
+	if (ret)
+		dev_err(dev, "[cmd] token %x error %d\n", context->token, ret);
 
 out:
-	spin_lock(&cmd->context_lock);
-	context->next = cmd->free_head;
-	cmd->free_head = context - cmd->context;
-	spin_unlock(&cmd->context_lock);
-
+	context->busy = 0;
 	return ret;
 }
 
@@ -195,7 +184,6 @@ int hns_roce_cmd_init(struct hns_roce_dev *hr_dev)
 {
 	struct device *dev = hr_dev->dev;
 
-	mutex_init(&hr_dev->cmd.hcr_mutex);
 	sema_init(&hr_dev->cmd.poll_sem, 1);
 	hr_dev->cmd.use_events = 0;
 	hr_dev->cmd.max_cmds = CMD_MAX_NUM;
@@ -226,16 +214,16 @@ int hns_roce_cmd_use_events(struct hns_roce_dev *hr_dev)
 	for (i = 0; i < hr_cmd->max_cmds; ++i) {
 		hr_cmd->context[i].token = i;
 		hr_cmd->context[i].next = i + 1;
+		init_completion(&hr_cmd->context[i].done);
 	}
-
-	hr_cmd->context[hr_cmd->max_cmds - 1].next = -1;
+	hr_cmd->context[hr_cmd->max_cmds - 1].next = 0;
 	hr_cmd->free_head = 0;
 
 	sema_init(&hr_cmd->event_sem, hr_cmd->max_cmds);
 	spin_lock_init(&hr_cmd->context_lock);
 
-	hr_cmd->token_mask = CMD_TOKEN_MASK;
 	hr_cmd->use_events = 1;
+	down(&hr_cmd->poll_sem);
 
 	return 0;
 }
@@ -246,6 +234,8 @@ void hns_roce_cmd_use_polling(struct hns_roce_dev *hr_dev)
 
 	kfree(hr_cmd->context);
 	hr_cmd->use_events = 0;
+
+	up(&hr_cmd->poll_sem);
 }
 
 struct hns_roce_cmd_mailbox *

drivers/infiniband/hw/hns/hns_roce_device.h

@@ -550,6 +550,7 @@ struct hns_roce_cmd_context {
 	int			next;
 	u64			out_param;
 	u16			token;
+	u16			busy;
 };
 
 struct hns_roce_cmdq {
@@ -565,11 +566,6 @@ struct hns_roce_cmdq {
 	spinlock_t		context_lock;
 	int			free_head;
 	struct hns_roce_cmd_context *context;
-	/*
-	 * Result of get integer part
-	 * which max_comds compute according a power of 2
-	 */
-	u16			token_mask;
 	/*
 	 * Process whether use event mode, init default non-zero
 	 * After the event queue of cmd event ready,