diag: Remove hdlc status dependeny on session_info

The patch removes the hdlc status dependency on session_info
protected by md_session_lock inserting delay in processing data
off peripheral.

CRs-Fixed: 2193991
Change-Id: Ia79c0efe82803c15ccae42b00d95258f52242eee
Signed-off-by: Manoj Prabhu B <bmanoj@codeaurora.org>

4 files changed, 218 insertions, 54 deletions

diff --git a/drivers/char/diag/diagchar.h b/drivers/char/diag/diagchar.h
index 75080f0d4c39..afea5f40bfee 100644
--- a/drivers/char/diag/diagchar.h
+++ b/drivers/char/diag/diagchar.h
@@ -1,4 +1,4 @@
-/* Copyright (c) 2008-2017, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2008-2018, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -580,6 +580,7 @@ struct diagchar_dev {
 	/* buffer for updating mask to peripherals */
 	unsigned char *buf_feature_mask_update;
 	uint8_t hdlc_disabled;
+	uint8_t p_hdlc_disabled[NUM_MD_SESSIONS];
 	struct mutex hdlc_disable_mutex;
 	struct mutex hdlc_recovery_mutex;
 	struct timer_list hdlc_reset_timer;
@@ -604,6 +605,7 @@ struct diagchar_dev {
 	struct work_struct diag_drain_work;
 	struct work_struct update_user_clients;
 	struct work_struct update_md_clients;
+	struct work_struct diag_hdlc_reset_work;
 	struct workqueue_struct *diag_cntl_wq;
 	uint8_t log_on_demand_support;
 	uint8_t *apps_req_buf;
@@ -683,5 +685,6 @@ void diag_record_stats(int type, int flag);
 
 struct diag_md_session_t *diag_md_session_get_pid(int pid);
 struct diag_md_session_t *diag_md_session_get_peripheral(uint8_t peripheral);
+int diag_md_session_match_pid_peripheral(int pid, uint8_t peripheral);
 
 #endif
diff --git a/drivers/char/diag/diagchar_core.c b/drivers/char/diag/diagchar_core.c
index ed982f426923..be7a565ca04e 100644
--- a/drivers/char/diag/diagchar_core.c
+++ b/drivers/char/diag/diagchar_core.c
@@ -252,18 +252,13 @@ static void diag_update_md_client_work_fn(struct work_struct *work)
 
 void diag_drain_work_fn(struct work_struct *work)
 {
-	struct diag_md_session_t *session_info = NULL;
 	uint8_t hdlc_disabled = 0;
 
 	timer_in_progress = 0;
 	mutex_lock(&apps_data_mutex);
-	mutex_lock(&driver->md_session_lock);
-	session_info = diag_md_session_get_peripheral(APPS_DATA);
-	if (session_info)
-		hdlc_disabled = session_info->hdlc_disabled;
-	else
-		hdlc_disabled = driver->hdlc_disabled;
-	mutex_unlock(&driver->md_session_lock);
+	mutex_lock(&driver->hdlc_disable_mutex);
+	hdlc_disabled = driver->p_hdlc_disabled[APPS_DATA];
+	mutex_unlock(&driver->hdlc_disable_mutex);
 	if (!hdlc_disabled)
 		diag_drain_apps_data(&hdlc_data);
 	else
@@ -1029,7 +1024,6 @@ static int diag_send_raw_data_remote(int proc, void *buf, int len,
 	struct diag_send_desc_type send = { NULL, NULL, DIAG_STATE_START, 0 };
 	struct diag_hdlc_dest_type enc = { NULL, NULL, 0 };
 	int bridge_index = proc - 1;
-	struct diag_md_session_t *session_info = NULL;
 	uint8_t hdlc_disabled = 0;
 
 	if (!buf)
@@ -1055,13 +1049,9 @@ static int diag_send_raw_data_remote(int proc, void *buf, int len,
 
 	if (driver->hdlc_encode_buf_len != 0)
 		return -EAGAIN;
-	mutex_lock(&driver->md_session_lock);
-	session_info = diag_md_session_get_peripheral(APPS_DATA);
-	if (session_info)
-		hdlc_disabled = session_info->hdlc_disabled;
-	else
-		hdlc_disabled = driver->hdlc_disabled;
-	mutex_unlock(&driver->md_session_lock);
+	mutex_lock(&driver->hdlc_disable_mutex);
+	hdlc_disabled = driver->p_hdlc_disabled[APPS_DATA];
+	mutex_unlock(&driver->hdlc_disable_mutex);
 	if (hdlc_disabled) {
 		if (len < 4) {
 			pr_err("diag: In %s, invalid len: %d of non_hdlc pkt",
@@ -1483,6 +1473,43 @@ struct diag_md_session_t *diag_md_session_get_peripheral(uint8_t peripheral)
 	return driver->md_session_map[peripheral];
 }
 
+/*
+ * diag_md_session_match_pid_peripheral
+ *
+ *	1. Pass valid PID and get all the peripherals in logging session
+ *		for that PID
+ *	2. Pass valid Peipheral and get the pid logging for that peripheral
+ *
+ */
+
+int diag_md_session_match_pid_peripheral(int pid,
+	uint8_t peripheral)
+{
+	int i, flag = 0;
+
+	if (pid <= 0 || peripheral >= NUM_MD_SESSIONS)
+		return -EINVAL;
+
+	if (!peripheral) {
+		for (i = 0; i < NUM_MD_SESSIONS; i++) {
+			if (driver->md_session_map[i] &&
+			    driver->md_session_map[i]->pid == pid) {
+				peripheral |= 1 << i;
+				flag = 1;
+			}
+		}
+		if (flag)
+			return peripheral;
+	}
+
+	if (!pid) {
+		if (driver->md_session_map[peripheral])
+			return driver->md_session_map[peripheral]->pid;
+	}
+
+	return -EINVAL;
+}
+
 static int diag_md_peripheral_switch(int pid,
 				int peripheral_mask, int req_mode) {
 	int i, bit = 0;
@@ -1637,6 +1664,13 @@ static int diag_md_session_check(int curr_mode, int req_mode,
 			}
 			err = diag_md_session_create(DIAG_MD_PERIPHERAL,
 				param->peripheral_mask, DIAG_LOCAL_PROC);
+			mutex_lock(&driver->hdlc_disable_mutex);
+			for (i = 0; i < NUM_MD_SESSIONS; i++) {
+				if ((param->peripheral_mask > 0) &&
+					(param->peripheral_mask & (1 << i)))
+					driver->p_hdlc_disabled[i] = 0;
+			}
+			mutex_unlock(&driver->hdlc_disable_mutex);
 		}
 		*change_mode = 1;
 		return err;
@@ -2085,11 +2119,14 @@ static int diag_ioctl_dci_support(unsigned long ioarg)
 
 static int diag_ioctl_hdlc_toggle(unsigned long ioarg)
 {
-	uint8_t hdlc_support;
+	uint8_t hdlc_support, i;
+	int peripheral = -EINVAL;
 	struct diag_md_session_t *session_info = NULL;
+
 	if (copy_from_user(&hdlc_support, (void __user *)ioarg,
 				sizeof(uint8_t)))
 		return -EFAULT;
+
 	mutex_lock(&driver->hdlc_disable_mutex);
 	mutex_lock(&driver->md_session_lock);
 	session_info = diag_md_session_get_pid(current->tgid);
@@ -2097,6 +2134,25 @@ static int diag_ioctl_hdlc_toggle(unsigned long ioarg)
 		session_info->hdlc_disabled = hdlc_support;
 	else
 		driver->hdlc_disabled = hdlc_support;
+
+	peripheral =
+		diag_md_session_match_pid_peripheral(current->tgid,
+		0);
+	for (i = 0; i < NUM_MD_SESSIONS; i++) {
+		if (peripheral > 0 && session_info) {
+			if (peripheral & (1 << i))
+				driver->p_hdlc_disabled[i] =
+				session_info->hdlc_disabled;
+			else if (!diag_md_session_get_peripheral(i))
+				driver->p_hdlc_disabled[i] =
+				driver->hdlc_disabled;
+		} else {
+			if (!diag_md_session_get_peripheral(i))
+				driver->p_hdlc_disabled[i] =
+				driver->hdlc_disabled;
+		}
+	}
+
 	mutex_unlock(&driver->md_session_lock);
 	mutex_unlock(&driver->hdlc_disable_mutex);
 	diag_update_md_clients(HDLC_SUPPORT_TYPE);
@@ -2970,7 +3026,6 @@ static int diag_user_process_apps_data(const char __user *buf, int len,
 	int stm_size = 0;
 	const int mempool = POOL_TYPE_COPY;
 	unsigned char *user_space_data = NULL;
-	struct diag_md_session_t *session_info = NULL;
 	uint8_t hdlc_disabled;
 
 	if (!buf || len <= 0 || len > DIAG_MAX_RSP_SIZE) {
@@ -3024,13 +3079,7 @@ static int diag_user_process_apps_data(const char __user *buf, int len,
 
 	mutex_lock(&apps_data_mutex);
 	mutex_lock(&driver->hdlc_disable_mutex);
-	mutex_lock(&driver->md_session_lock);
-	session_info = diag_md_session_get_peripheral(APPS_DATA);
-	if (session_info)
-		hdlc_disabled = session_info->hdlc_disabled;
-	else
-		hdlc_disabled = driver->hdlc_disabled;
-	mutex_unlock(&driver->md_session_lock);
+	hdlc_disabled = driver->p_hdlc_disabled[APPS_DATA];
 	if (hdlc_disabled)
 		ret = diag_process_apps_data_non_hdlc(user_space_data, len,
 						      pkt_type);
diff --git a/drivers/char/diag/diagfwd.c b/drivers/char/diag/diagfwd.c
index f6027ae96833..c7b46304dc84 100644
--- a/drivers/char/diag/diagfwd.c
+++ b/drivers/char/diag/diagfwd.c
@@ -49,6 +49,11 @@
 #define STM_RSP_STATUS_INDEX		8
 #define STM_RSP_NUM_BYTES		9
 
+struct diag_md_hdlc_reset_work {
+	int pid;
+	struct work_struct work;
+};
+
 static int timestamp_switch;
 module_param(timestamp_switch, int, 0644);
 
@@ -436,6 +441,7 @@ static void diag_send_rsp(unsigned char *buf, int len, int pid)
 {
 	struct diag_md_session_t *session_info = NULL, *info = NULL;
 	uint8_t hdlc_disabled;
+
 	mutex_lock(&driver->md_session_lock);
 	info = diag_md_session_get_pid(pid);
 	session_info = (info) ? info :
@@ -445,6 +451,7 @@ static void diag_send_rsp(unsigned char *buf, int len, int pid)
 	else
 		hdlc_disabled = driver->hdlc_disabled;
 	mutex_unlock(&driver->md_session_lock);
+
 	if (hdlc_disabled)
 		pack_rsp_and_send(buf, len, pid);
 	else
@@ -948,7 +955,7 @@ void diag_send_error_rsp(unsigned char *buf, int len,
 int diag_process_apps_pkt(unsigned char *buf, int len, int pid)
 {
 	int i, p_mask = 0;
-	int mask_ret;
+	int mask_ret, peripheral = -EINVAL;
 	int write_len = 0;
 	unsigned char *temp = NULL;
 	struct diag_cmd_reg_entry_t entry;
@@ -1175,6 +1182,22 @@ int diag_process_apps_pkt(unsigned char *buf, int len, int pid)
 			info->hdlc_disabled = 1;
 		else
 			driver->hdlc_disabled = 1;
+		peripheral =
+			diag_md_session_match_pid_peripheral(pid, 0);
+		for (i = 0; i < NUM_MD_SESSIONS; i++) {
+			if (peripheral > 0 && info) {
+				if (peripheral & (1 << i))
+					driver->p_hdlc_disabled[i] =
+					info->hdlc_disabled;
+				else if (!diag_md_session_get_peripheral(i))
+					driver->p_hdlc_disabled[i] =
+					driver->hdlc_disabled;
+			} else {
+				if (!diag_md_session_get_peripheral(i))
+					driver->p_hdlc_disabled[i] =
+					driver->hdlc_disabled;
+			}
+		}
 		mutex_unlock(&driver->md_session_lock);
 		diag_update_md_clients(HDLC_SUPPORT_TYPE);
 		mutex_unlock(&driver->hdlc_disable_mutex);
@@ -1350,8 +1373,17 @@ static int diagfwd_mux_close(int id, int mode)
 		pr_debug("diag: In %s, re-enabling HDLC encoding\n",
 		       __func__);
 		mutex_lock(&driver->hdlc_disable_mutex);
-		if (driver->md_session_mode == DIAG_MD_NONE)
+		if (driver->md_session_mode == DIAG_MD_NONE) {
 			driver->hdlc_disabled = 0;
+			/*
+			 * HDLC encoding is re-enabled when
+			 * there is logical/physical disconnection of diag
+			 * to USB.
+			 */
+			for (i = 0; i < NUM_MD_SESSIONS; i++)
+				driver->p_hdlc_disabled[i] =
+				driver->hdlc_disabled;
+		}
 		mutex_unlock(&driver->hdlc_disable_mutex);
 		queue_work(driver->diag_wq,
 			&(driver->update_user_clients));
@@ -1366,6 +1398,7 @@ static uint8_t hdlc_reset;
 static void hdlc_reset_timer_start(int pid)
 {
 	struct diag_md_session_t *info = NULL;
+
 	mutex_lock(&driver->md_session_lock);
 	info = diag_md_session_get_pid(pid);
 	if (!hdlc_timer_in_progress) {
@@ -1380,30 +1413,99 @@ static void hdlc_reset_timer_start(int pid)
 	mutex_unlock(&driver->md_session_lock);
 }
 
+/*
+ * diag_timer_work_fn
+ * Queued in workqueue to protect md_session_info structure
+ *
+ * Update hdlc_disabled for each peripheral
+ * which are not in any md_session_info.
+ *
+ */
+static void diag_timer_work_fn(struct work_struct *work)
+{
+	int i = 0;
+	struct diag_md_session_t *session_info = NULL;
+
+	mutex_lock(&driver->hdlc_disable_mutex);
+	driver->hdlc_disabled = 0;
+	mutex_lock(&driver->md_session_lock);
+	for (i = 0; i < NUM_MD_SESSIONS; i++) {
+		session_info = diag_md_session_get_peripheral(i);
+		if (!session_info)
+			driver->p_hdlc_disabled[i] =
+			driver->hdlc_disabled;
+	}
+	mutex_unlock(&driver->md_session_lock);
+	mutex_unlock(&driver->hdlc_disable_mutex);
+}
+
+/*
+ * diag_md_timer_work_fn
+ * Queued in workqueue to protect md_session_info structure
+ *
+ * Update hdlc_disabled for each peripheral
+ * which are in any md_session_info
+ *
+ */
+static void diag_md_timer_work_fn(struct work_struct *work)
+{
+	int peripheral = -EINVAL, i = 0;
+	struct diag_md_session_t *session_info = NULL;
+	struct diag_md_hdlc_reset_work *hdlc_work = container_of(work,
+			struct diag_md_hdlc_reset_work, work);
+
+	if (!hdlc_work)
+		return;
+
+	mutex_lock(&driver->hdlc_disable_mutex);
+	mutex_lock(&driver->md_session_lock);
+	session_info = diag_md_session_get_pid(hdlc_work->pid);
+	if (session_info)
+		session_info->hdlc_disabled = 0;
+	peripheral =
+		diag_md_session_match_pid_peripheral(hdlc_work->pid, 0);
+	if (peripheral > 0 && session_info) {
+		for (i = 0; i < NUM_MD_SESSIONS; i++) {
+			if (peripheral & (1 << i))
+				driver->p_hdlc_disabled[i] =
+				session_info->hdlc_disabled;
+		}
+	}
+	kfree(hdlc_work);
+	mutex_unlock(&driver->md_session_lock);
+	mutex_unlock(&driver->hdlc_disable_mutex);
+}
+
 static void hdlc_reset_timer_func(unsigned long data)
 {
 	pr_debug("diag: In %s, re-enabling HDLC encoding\n",
 		       __func__);
+
 	if (hdlc_reset) {
-		driver->hdlc_disabled = 0;
-		queue_work(driver->diag_wq,
-			&(driver->update_user_clients));
+		queue_work(driver->diag_wq, &(driver->diag_hdlc_reset_work));
+		queue_work(driver->diag_wq, &(driver->update_user_clients));
 	}
 	hdlc_timer_in_progress = 0;
 }
 
 void diag_md_hdlc_reset_timer_func(unsigned long pid)
 {
-	struct diag_md_session_t *session_info = NULL;
+	struct diag_md_hdlc_reset_work *hdlc_reset_work = NULL;
 
 	pr_debug("diag: In %s, re-enabling HDLC encoding\n",
 		       __func__);
+	hdlc_reset_work = kmalloc(sizeof(*hdlc_reset_work), GFP_ATOMIC);
+	if (!hdlc_reset_work) {
+		DIAG_LOG(DIAG_DEBUG_PERIPHERALS,
+			"diag: Could not allocate hdlc_reset_work\n");
+		hdlc_timer_in_progress = 0;
+		return;
+	}
 	if (hdlc_reset) {
-		session_info = diag_md_session_get_pid(pid);
-		if (session_info)
-			session_info->hdlc_disabled = 0;
-		queue_work(driver->diag_wq,
-			&(driver->update_md_clients));
+		hdlc_reset_work->pid = pid;
+		INIT_WORK(&hdlc_reset_work->work, diag_md_timer_work_fn);
+		queue_work(driver->diag_wq, &(hdlc_reset_work->work));
+		queue_work(driver->diag_wq, &(driver->update_md_clients));
 	}
 	hdlc_timer_in_progress = 0;
 }
@@ -1411,7 +1513,7 @@ void diag_md_hdlc_reset_timer_func(unsigned long pid)
 static void diag_hdlc_start_recovery(unsigned char *buf, int len,
 				     int pid)
 {
-	int i;
+	int i, peripheral = -EINVAL;
 	static uint32_t bad_byte_counter;
 	unsigned char *start_ptr = NULL;
 	struct diag_pkt_frame_t *actual_pkt = NULL;
@@ -1443,6 +1545,24 @@ static void diag_hdlc_start_recovery(unsigned char *buf, int len,
 				info->hdlc_disabled = 0;
 			else
 				driver->hdlc_disabled = 0;
+
+			peripheral =
+				diag_md_session_match_pid_peripheral(pid, 0);
+			for (i = 0; i < NUM_MD_SESSIONS; i++) {
+				if (peripheral > 0 && info) {
+					if (peripheral & (1 << i))
+						driver->p_hdlc_disabled[i] =
+						info->hdlc_disabled;
+					else if (
+					!diag_md_session_get_peripheral(i))
+						driver->p_hdlc_disabled[i] =
+						driver->hdlc_disabled;
+				} else {
+					if (!diag_md_session_get_peripheral(i))
+						driver->p_hdlc_disabled[i] =
+						driver->hdlc_disabled;
+				}
+			}
 			mutex_unlock(&driver->md_session_lock);
 			mutex_unlock(&driver->hdlc_disable_mutex);
 			diag_update_md_clients(HDLC_SUPPORT_TYPE);
@@ -1700,6 +1820,8 @@ int diagfwd_init(void)
 	INIT_LIST_HEAD(&driver->cmd_reg_list);
 	driver->cmd_reg_count = 0;
 	mutex_init(&driver->cmd_reg_mutex);
+	INIT_WORK(&(driver->diag_hdlc_reset_work),
+			diag_timer_work_fn);
 
 	for (i = 0; i < NUM_PERIPHERALS; i++) {
 		driver->feature[i].separate_cmd_rsp = 0;
diff --git a/drivers/char/diag/diagfwd_peripheral.c b/drivers/char/diag/diagfwd_peripheral.c
index a7abe3dafb69..6b74c0056d1b 100644
--- a/drivers/char/diag/diagfwd_peripheral.c
+++ b/drivers/char/diag/diagfwd_peripheral.c
@@ -284,7 +284,6 @@ static void diagfwd_data_process_done(struct diagfwd_info *fwd_info,
 	int err = 0;
 	int write_len = 0, peripheral = 0;
 	unsigned char *write_buf = NULL;
-	struct diag_md_session_t *session_info = NULL;
 	uint8_t hdlc_disabled = 0;
 
 	if (!fwd_info || !buf || len <= 0) {
@@ -316,13 +315,9 @@ static void diagfwd_data_process_done(struct diagfwd_info *fwd_info,
 		diag_ws_release();
 		return;
 	}
-	mutex_lock(&driver->md_session_lock);
-	session_info = diag_md_session_get_peripheral(peripheral);
-	if (session_info)
-		hdlc_disabled = session_info->hdlc_disabled;
-	else
-		hdlc_disabled = driver->hdlc_disabled;
-	mutex_unlock(&driver->md_session_lock);
+
+	hdlc_disabled = driver->p_hdlc_disabled[peripheral];
+
 	if (hdlc_disabled) {
 		/* The data is raw and and on APPS side HDLC is disabled */
 		if (!buf) {
@@ -615,7 +610,6 @@ static void diagfwd_data_read_done(struct diagfwd_info *fwd_info,
 	int write_len = 0;
 	unsigned char *write_buf = NULL;
 	struct diagfwd_buf_t *temp_buf = NULL;
-	struct diag_md_session_t *session_info = NULL;
 	uint8_t hdlc_disabled = 0;
 
 	if (!fwd_info || !buf || len <= 0) {
@@ -637,13 +631,9 @@ static void diagfwd_data_read_done(struct diagfwd_info *fwd_info,
 
 	mutex_lock(&driver->hdlc_disable_mutex);
 	mutex_lock(&fwd_info->data_mutex);
-	mutex_lock(&driver->md_session_lock);
-	session_info = diag_md_session_get_peripheral(fwd_info->peripheral);
-	if (session_info)
-		hdlc_disabled = session_info->hdlc_disabled;
-	else
-		hdlc_disabled = driver->hdlc_disabled;
-	mutex_unlock(&driver->md_session_lock);
+
+	hdlc_disabled = driver->p_hdlc_disabled[fwd_info->peripheral];
+
 	if (!driver->feature[fwd_info->peripheral].encode_hdlc) {
 		if (fwd_info->buf_1 && fwd_info->buf_1->data == buf) {
 			temp_buf = fwd_info->buf_1;