| /* Copyright (c) 2017, 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 |
| * only version 2 as published by the Free Software Foundation. |
| * |
| * 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. |
| */ |
| |
| #define pr_fmt(fmt) "%s:%d " fmt, __func__, __LINE__ |
| |
| #include <linux/slab.h> |
| #include <linux/spinlock.h> |
| #include <linux/interrupt.h> |
| #include <linux/list.h> |
| #include <linux/ratelimit.h> |
| #include "cam_tasklet_util.h" |
| #include "cam_irq_controller.h" |
| |
| #undef CDBG |
| #define CDBG(fmt, args...) pr_debug(fmt, ##args) |
| |
| #define CAM_TASKLETQ_SIZE 256 |
| |
| static void cam_tasklet_action(unsigned long data); |
| |
| /** |
| * struct cam_tasklet_queue_cmd: |
| * @Brief: Structure associated with each slot in the |
| * tasklet queue |
| * |
| * @list: list_head member for each entry in queue |
| * @payload: Payload structure for the event. This will be |
| * passed to the handler function |
| * @bottom_half_handler: Function pointer for event handler in bottom |
| * half context |
| * |
| */ |
| struct cam_tasklet_queue_cmd { |
| struct list_head list; |
| void *payload; |
| CAM_IRQ_HANDLER_BOTTOM_HALF bottom_half_handler; |
| }; |
| |
| /** |
| * struct cam_tasklet_info: |
| * @Brief: Tasklet private structure |
| * |
| * @list: list_head member for each tasklet |
| * @index: Instance id for the tasklet |
| * @tasklet_lock: Spin lock |
| * @tasklet_active: Atomic variable to control tasklet state |
| * @tasklet: Tasklet structure used to schedule bottom half |
| * @free_cmd_list: List of free tasklet queue cmd for use |
| * @used_cmd_list: List of used tasklet queue cmd |
| * @cmd_queue: Array of tasklet cmd for storage |
| * @ctx_priv: Private data passed to the handling function |
| * |
| */ |
| struct cam_tasklet_info { |
| struct list_head list; |
| uint32_t index; |
| spinlock_t tasklet_lock; |
| atomic_t tasklet_active; |
| struct tasklet_struct tasklet; |
| |
| struct list_head free_cmd_list; |
| struct list_head used_cmd_list; |
| struct cam_tasklet_queue_cmd cmd_queue[CAM_TASKLETQ_SIZE]; |
| |
| void *ctx_priv; |
| }; |
| |
| /** |
| * cam_tasklet_get_cmd() |
| * |
| * @brief: Get free cmd from tasklet |
| * |
| * @tasklet: Tasklet Info structure to get cmd from |
| * @tasklet_cmd: Return tasklet_cmd pointer if successful |
| * |
| * @return: 0: Success |
| * Negative: Failure |
| */ |
| static int cam_tasklet_get_cmd( |
| struct cam_tasklet_info *tasklet, |
| struct cam_tasklet_queue_cmd **tasklet_cmd) |
| { |
| int rc = 0; |
| unsigned long flags; |
| |
| *tasklet_cmd = NULL; |
| |
| if (!atomic_read(&tasklet->tasklet_active)) { |
| pr_err_ratelimited("Tasklet is not active!\n"); |
| rc = -EPIPE; |
| return rc; |
| } |
| |
| spin_lock_irqsave(&tasklet->tasklet_lock, flags); |
| if (list_empty(&tasklet->free_cmd_list)) { |
| pr_err_ratelimited("No more free tasklet cmd!\n"); |
| rc = -ENODEV; |
| goto spin_unlock; |
| } else { |
| *tasklet_cmd = list_first_entry(&tasklet->free_cmd_list, |
| struct cam_tasklet_queue_cmd, list); |
| list_del_init(&(*tasklet_cmd)->list); |
| } |
| |
| spin_unlock: |
| spin_unlock_irqrestore(&tasklet->tasklet_lock, flags); |
| return rc; |
| } |
| |
| /** |
| * cam_tasklet_put_cmd() |
| * |
| * @brief: Put back cmd to free list |
| * |
| * @tasklet: Tasklet Info structure to put cmd into |
| * @tasklet_cmd: tasklet_cmd pointer that needs to be put back |
| * |
| * @return: Void |
| */ |
| static void cam_tasklet_put_cmd( |
| struct cam_tasklet_info *tasklet, |
| struct cam_tasklet_queue_cmd **tasklet_cmd) |
| { |
| unsigned long flags; |
| |
| spin_lock_irqsave(&tasklet->tasklet_lock, flags); |
| list_add_tail(&(*tasklet_cmd)->list, |
| &tasklet->free_cmd_list); |
| spin_unlock_irqrestore(&tasklet->tasklet_lock, flags); |
| } |
| |
| /** |
| * cam_tasklet_dequeue_cmd() |
| * |
| * @brief: Initialize the tasklet info structure |
| * |
| * @hw_mgr_ctx: Private Ctx data that will be passed to the handler |
| * function |
| * @idx: Index of tasklet used as identity |
| * @tasklet_action: Tasklet callback function that will be called |
| * when tasklet runs on CPU |
| * |
| * @return: 0: Success |
| * Negative: Failure |
| */ |
| static int cam_tasklet_dequeue_cmd( |
| struct cam_tasklet_info *tasklet, |
| struct cam_tasklet_queue_cmd **tasklet_cmd) |
| { |
| int rc = 0; |
| unsigned long flags; |
| |
| *tasklet_cmd = NULL; |
| |
| if (!atomic_read(&tasklet->tasklet_active)) { |
| pr_err("Tasklet is not active!\n"); |
| rc = -EPIPE; |
| return rc; |
| } |
| |
| CDBG("Dequeue before lock.\n"); |
| spin_lock_irqsave(&tasklet->tasklet_lock, flags); |
| if (list_empty(&tasklet->used_cmd_list)) { |
| CDBG("End of list reached. Exit\n"); |
| rc = -ENODEV; |
| goto spin_unlock; |
| } else { |
| *tasklet_cmd = list_first_entry(&tasklet->used_cmd_list, |
| struct cam_tasklet_queue_cmd, list); |
| list_del_init(&(*tasklet_cmd)->list); |
| CDBG("Dequeue Successful\n"); |
| } |
| |
| spin_unlock: |
| spin_unlock_irqrestore(&tasklet->tasklet_lock, flags); |
| return rc; |
| } |
| |
| int cam_tasklet_enqueue_cmd( |
| void *bottom_half, |
| void *handler_priv, |
| void *evt_payload_priv, |
| CAM_IRQ_HANDLER_BOTTOM_HALF bottom_half_handler) |
| { |
| struct cam_tasklet_info *tasklet = bottom_half; |
| struct cam_tasklet_queue_cmd *tasklet_cmd = NULL; |
| unsigned long flags; |
| int rc; |
| |
| if (!bottom_half) { |
| pr_err("NULL bottom half\n"); |
| return -EINVAL; |
| } |
| |
| rc = cam_tasklet_get_cmd(tasklet, &tasklet_cmd); |
| |
| if (tasklet_cmd) { |
| CDBG("%s: Enqueue tasklet cmd\n", __func__); |
| tasklet_cmd->bottom_half_handler = bottom_half_handler; |
| tasklet_cmd->payload = evt_payload_priv; |
| spin_lock_irqsave(&tasklet->tasklet_lock, flags); |
| list_add_tail(&tasklet_cmd->list, |
| &tasklet->used_cmd_list); |
| spin_unlock_irqrestore(&tasklet->tasklet_lock, flags); |
| tasklet_schedule(&tasklet->tasklet); |
| } else { |
| pr_err("%s: tasklet cmd is NULL!\n", __func__); |
| } |
| |
| return rc; |
| } |
| |
| int cam_tasklet_init( |
| void **tasklet_info, |
| void *hw_mgr_ctx, |
| uint32_t idx) |
| { |
| int i; |
| struct cam_tasklet_info *tasklet = NULL; |
| |
| tasklet = kzalloc(sizeof(struct cam_tasklet_info), GFP_KERNEL); |
| if (!tasklet) { |
| CDBG("Error! Unable to allocate memory for tasklet"); |
| *tasklet_info = NULL; |
| return -ENOMEM; |
| } |
| |
| tasklet->ctx_priv = hw_mgr_ctx; |
| tasklet->index = idx; |
| spin_lock_init(&tasklet->tasklet_lock); |
| memset(tasklet->cmd_queue, 0, sizeof(tasklet->cmd_queue)); |
| INIT_LIST_HEAD(&tasklet->free_cmd_list); |
| INIT_LIST_HEAD(&tasklet->used_cmd_list); |
| for (i = 0; i < CAM_TASKLETQ_SIZE; i++) { |
| INIT_LIST_HEAD(&tasklet->cmd_queue[i].list); |
| list_add_tail(&tasklet->cmd_queue[i].list, |
| &tasklet->free_cmd_list); |
| } |
| tasklet_init(&tasklet->tasklet, cam_tasklet_action, |
| (unsigned long)tasklet); |
| cam_tasklet_stop(tasklet); |
| |
| *tasklet_info = tasklet; |
| |
| return 0; |
| } |
| |
| void cam_tasklet_deinit(void **tasklet_info) |
| { |
| struct cam_tasklet_info *tasklet = *tasklet_info; |
| |
| atomic_set(&tasklet->tasklet_active, 0); |
| tasklet_kill(&tasklet->tasklet); |
| kfree(tasklet); |
| *tasklet_info = NULL; |
| } |
| |
| int cam_tasklet_start(void *tasklet_info) |
| { |
| struct cam_tasklet_info *tasklet = tasklet_info; |
| struct cam_tasklet_queue_cmd *tasklet_cmd; |
| struct cam_tasklet_queue_cmd *tasklet_cmd_temp; |
| |
| if (atomic_read(&tasklet->tasklet_active)) { |
| pr_err("Tasklet already active. idx = %d\n", tasklet->index); |
| return -EBUSY; |
| } |
| atomic_set(&tasklet->tasklet_active, 1); |
| |
| /* flush the command queue first */ |
| list_for_each_entry_safe(tasklet_cmd, tasklet_cmd_temp, |
| &tasklet->used_cmd_list, list) { |
| list_del_init(&tasklet_cmd->list); |
| list_add_tail(&tasklet_cmd->list, &tasklet->free_cmd_list); |
| } |
| |
| tasklet_enable(&tasklet->tasklet); |
| |
| return 0; |
| } |
| |
| void cam_tasklet_stop(void *tasklet_info) |
| { |
| struct cam_tasklet_info *tasklet = tasklet_info; |
| |
| atomic_set(&tasklet->tasklet_active, 0); |
| tasklet_disable(&tasklet->tasklet); |
| } |
| |
| /* |
| * cam_tasklet_action() |
| * |
| * @brief: Process function that will be called when tasklet runs |
| * on CPU |
| * |
| * @data: Tasklet Info structure that is passed in tasklet_init |
| * |
| * @return: Void |
| */ |
| static void cam_tasklet_action(unsigned long data) |
| { |
| struct cam_tasklet_info *tasklet_info = NULL; |
| struct cam_tasklet_queue_cmd *tasklet_cmd = NULL; |
| |
| tasklet_info = (struct cam_tasklet_info *)data; |
| |
| while (!cam_tasklet_dequeue_cmd(tasklet_info, &tasklet_cmd)) { |
| tasklet_cmd->bottom_half_handler(tasklet_info->ctx_priv, |
| tasklet_cmd->payload); |
| cam_tasklet_put_cmd(tasklet_info, &tasklet_cmd); |
| } |
| } |
| |