[RFC v2 3/3] CMDQ: Mediatek CMDQ driver

[HS Liao]

This patch is first version of Mediatek Command Queue(CMDQ) driver. The
CMDQ is used to help read/write registers with critical time limitation,
such as updating display configuration during the vblank. It controls
Global Command Engine (GCE) hardware to achieve this requirement.
Currently, CMDQ only supports display related hardwares, but we expect
it can be extended to other hardwares for future requirements.

Signed-off-by: HS Liao <hs.liao@xxxxxxxxxxxx>
---
 drivers/soc/mediatek/Kconfig    |   10 +
 drivers/soc/mediatek/Makefile   |    1 +
 drivers/soc/mediatek/mtk-cmdq.c | 2788 +++++++++++++++++++++++++++++++++++++++
 include/soc/mediatek/cmdq.h     |  211 +++
 4 files changed, 3010 insertions(+)
 create mode 100644 drivers/soc/mediatek/mtk-cmdq.c
 create mode 100644 include/soc/mediatek/cmdq.h

diff --git a/drivers/soc/mediatek/Kconfig b/drivers/soc/mediatek/Kconfig
index 0a4ea80..c4ad75c 100644
--- a/drivers/soc/mediatek/Kconfig
+++ b/drivers/soc/mediatek/Kconfig
@@ -1,6 +1,16 @@
 #
 # MediaTek SoC drivers
 #
+config MTK_CMDQ
+	bool "MediaTek CMDQ Support"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	select MTK_INFRACFG
+	help
+	  Say yes here to add support for the MediaTek Command Queue (CMDQ)
+	  driver. The CMDQ is used to help read/write registers with critical
+	  time limitation, such as updating display configuration during the
+	  vblank.
+
 config MTK_INFRACFG
 	bool "MediaTek INFRACFG Support"
 	depends on ARCH_MEDIATEK || COMPILE_TEST
diff --git a/drivers/soc/mediatek/Makefile b/drivers/soc/mediatek/Makefile
index 12998b0..f7397ef 100644
--- a/drivers/soc/mediatek/Makefile
+++ b/drivers/soc/mediatek/Makefile
@@ -1,3 +1,4 @@
+obj-$(CONFIG_MTK_CMDQ) += mtk-cmdq.o
 obj-$(CONFIG_MTK_INFRACFG) += mtk-infracfg.o
 obj-$(CONFIG_MTK_PMIC_WRAP) += mtk-pmic-wrap.o
 obj-$(CONFIG_MTK_SCPSYS) += mtk-scpsys.o
diff --git a/drivers/soc/mediatek/mtk-cmdq.c b/drivers/soc/mediatek/mtk-cmdq.c
new file mode 100644
index 0000000..9f3e7af
--- /dev/null
+++ b/drivers/soc/mediatek/mtk-cmdq.c
@@ -0,0 +1,2788 @@
+/*
+ * Copyright (c) 2015 MediaTek Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License 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.
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/dma-mapping.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/iopoll.h>
+#include <linux/kernel.h>
+#include <linux/kthread.h>
+#include <linux/ktime.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/suspend.h>
+#include <linux/workqueue.h>
+#include <soc/mediatek/cmdq.h>
+
+#define CMDQ_MAX_THREAD_COUNT		3 /* general, main, sub */
+#define CMDQ_MAX_TASK_IN_THREAD		2
+
+#define CMDQ_INITIAL_CMD_BLOCK_SIZE	PAGE_SIZE
+#define CMDQ_CMD_BUF_POOL_BUF_SIZE	(128 * 1024)
+#define CMDQ_CMD_BUF_POOL_BUF_NUM	6 /* (general + main + sub) * 2 = 6 */
+#define CMDQ_INST_SIZE			8 /* instruction is 64-bit */
+
+/*
+ * cmdq_thread cookie value is from 0 to CMDQ_MAX_COOKIE_VALUE.
+ * And, this value also be used as MASK.
+ */
+#define CMDQ_MAX_COOKIE_VALUE		0xffff
+#define CMDQ_COOKIE_MASK		CMDQ_MAX_COOKIE_VALUE
+
+#define CMDQ_DEFAULT_TIMEOUT_MS		1000
+#define CMDQ_ACQUIRE_THREAD_TIMEOUT_MS	5000
+#define CMDQ_PREALARM_TIMEOUT_NS	200000000
+
+#define CMDQ_DRIVER_DEVICE_NAME		"mtk_cmdq"
+
+#define CMDQ_CLK_NAME			"gce"
+
+#define CMDQ_CURR_IRQ_STATUS_OFFSET	0x010
+#define CMDQ_CURR_LOADED_THR_OFFSET	0x018
+#define CMDQ_THR_SLOT_CYCLES_OFFSET	0x030
+#define CMDQ_THR_EXEC_CYCLES_OFFSET	0x034
+#define CMDQ_THR_TIMEOUT_TIMER_OFFSET	0x038
+#define CMDQ_BUS_CONTROL_TYPE_OFFSET	0x040
+
+#define CMDQ_SYNC_TOKEN_ID_OFFSET	0x060
+#define CMDQ_SYNC_TOKEN_VAL_OFFSET	0x064
+#define CMDQ_SYNC_TOKEN_UPD_OFFSET	0x068
+
+#define CMDQ_GPR_SHIFT			0x004
+#define CMDQ_GPR_OFFSET			0x080
+
+#define CMDQ_THR_BASE			0x100
+#define CMDQ_THR_SHIFT			0x080
+#define CMDQ_THR_WARM_RESET_OFFSET	0x00
+#define CMDQ_THR_ENABLE_TASK_OFFSET	0x04
+#define CMDQ_THR_SUSPEND_TASK_OFFSET	0x08
+#define CMDQ_THR_CURR_STATUS_OFFSET	0x0c
+#define CMDQ_THR_IRQ_STATUS_OFFSET	0x10
+#define CMDQ_THR_IRQ_ENABLE_OFFSET	0x14
+#define CMDQ_THR_CURR_ADDR_OFFSET	0x20
+#define CMDQ_THR_END_ADDR_OFFSET	0x24
+#define CMDQ_THR_EXEC_CNT_OFFSET	0x28
+#define CMDQ_THR_CFG_OFFSET		0x40
+#define CMDQ_THR_INST_CYCLES_OFFSET	0x50
+
+#define CMDQ_SYNC_TOKEN_SET		BIT(16)
+#define CMDQ_IRQ_MASK			0xffff
+
+#define CMDQ_THR_ENABLED		0x1
+#define CMDQ_THR_DISABLED		0x0
+#define CMDQ_THR_SUSPEND		0x1
+#define CMDQ_THR_RESUME			0x0
+#define CMDQ_THR_STATUS_SUSPENDED	BIT(1)
+#define CMDQ_THR_WARM_RESET		BIT(0)
+#define CMDQ_THR_SLOT_CYCLES		0x3200
+#define CMDQ_THR_NO_TIMEOUT		0x0
+#define CMDQ_THR_PRIORITY		3
+#define CMDQ_THR_IRQ_DONE		0x1
+#define CMDQ_THR_IRQ_ERROR		0x12
+#define CMDQ_THR_IRQ_EN			0x13 /* done + error */
+#define CMDQ_THR_IRQ_MASK		0x13
+#define CMDQ_THR_EXECUTING		BIT(31)
+
+#define CMDQ_ARG_A_MASK			0xffffff
+#define CMDQ_ARG_A_WRITE_MASK		0xffff
+#define CMDQ_ARG_A_SUBSYS_MASK		0x1f0000
+#define CMDQ_SUBSYS_MASK		0x1f
+
+#define CMDQ_OP_CODE_SHIFT		24
+#define CMDQ_SUBSYS_SHIFT		16
+
+#define CMDQ_JUMP_BY_OFFSET		0x10000000
+#define CMDQ_JUMP_BY_PA			0x10000001
+#define CMDQ_JUMP_TO_BEGIN		0x8
+
+#define CMDQ_WFE_UPDATE			BIT(31)
+#define CMDQ_WFE_WAIT			BIT(15)
+#define CMDQ_WFE_WAIT_VALUE		0x1
+
+#define CMDQ_MARK_NON_SUSPENDABLE	BIT(21) /* 53 - 32 = 21 */
+#define CMDQ_MARK_NOT_ADD_COUNTER	BIT(16) /* 48 - 32 = 16 */
+#define CMDQ_MARK_PREFETCH_MARKER	BIT(20)
+#define CMDQ_MARK_PREFETCH_MARKER_EN	BIT(17)
+#define CMDQ_MARK_PREFETCH_EN		BIT(16)
+
+#define CMDQ_EOC_IRQ_EN			BIT(0)
+
+#define CMDQ_ENABLE_MASK		BIT(0)
+
+struct cmdq_command {
+	struct cmdq	*cqctx;
+	u64		engine_flag;
+	void		*base; /* command buffer pointer */
+	size_t		size; /* command buffer size (bytes) */
+};
+
+enum cmdq_code {
+	/* These are actual HW op code. */
+	CMDQ_CODE_MOVE = 0x02,
+	CMDQ_CODE_WRITE = 0x04,
+	CMDQ_CODE_JUMP = 0x10,
+	CMDQ_CODE_WFE = 0x20,	/* wait for event (and clear) */
+	CMDQ_CODE_CLEAR_EVENT = 0x21,	/* clear event */
+	CMDQ_CODE_EOC = 0x40,	/* end of command */
+};
+
+enum cmdq_task_state {
+	TASK_STATE_IDLE,	/* free task */
+	TASK_STATE_BUSY,	/* task running on a thread */
+	TASK_STATE_KILLED,	/* task process being killed */
+	TASK_STATE_ERROR,	/* task execution error */
+	TASK_STATE_DONE,	/* task finished */
+	TASK_STATE_WAITING,	/* allocated but waiting for available thread */
+};
+
+struct cmdq_cmd_buf {
+	atomic_t		used;
+	void			*va;
+	dma_addr_t		pa;
+};
+
+struct cmdq_task_cb {
+	/* called by isr */
+	cmdq_async_flush_cb	isr_cb;
+	void			*isr_data;
+	/* called by releasing task */
+	cmdq_async_flush_cb	done_cb;
+	void			*done_data;
+};
+
+struct cmdq_thread;
+
+struct cmdq_task {
+	struct cmdq		*cqctx;
+	struct list_head	list_entry;
+
+	/* state for task life cycle */
+	enum cmdq_task_state	task_state;
+	/* virtual address of command buffer */
+	void			*va_base;
+	/* physical address of command buffer */
+	dma_addr_t		mva_base;
+	/* size of allocated command buffer */
+	size_t			buf_size;
+	/* It points to a cmdq_cmd_buf if this task use command buffer pool. */
+	struct cmdq_cmd_buf	*cmd_buf;
+
+	u64			engine_flag;
+	size_t			command_size;
+	u32			num_cmd;
+	int			reorder;
+	struct cmdq_thread	*thread;
+	/* flag of IRQ received */
+	int			irq_flag;
+	/* callback functions */
+	struct cmdq_task_cb	cb;
+	/* work item when auto release is used */
+	struct work_struct	auto_release_work;
+
+	ktime_t			submit; /* submit time */
+};
+
+struct cmdq_thread {
+	int			id;
+	void __iomem		*base;
+	u32			task_count;
+	u32			wait_cookie;
+	u32			next_cookie;
+	struct cmdq_task	*cur_task[CMDQ_MAX_TASK_IN_THREAD];
+};
+
+struct cmdq {
+	struct device		*dev;
+	struct notifier_block	pm_notifier;
+
+	void __iomem		*base;
+	u32			irq;
+
+	/*
+	 * task information
+	 * task_cache: struct cmdq_task object cache
+	 * task_free_list: unused free tasks
+	 * task_active_list: active tasks
+	 * task_consume_wait_queue_item: task consumption work item
+	 * task_auto_release_wq: auto-release workqueue
+	 * task_consume_wq: task consumption workqueue (for queued tasks)
+	 */
+	struct kmem_cache	*task_cache;
+	struct list_head	task_free_list;
+	struct list_head	task_active_list;
+	struct list_head	task_wait_list;
+	struct work_struct	task_consume_wait_queue_item;
+	struct workqueue_struct	*task_auto_release_wq;
+	struct workqueue_struct	*task_consume_wq;
+
+	struct cmdq_thread	thread[CMDQ_MAX_THREAD_COUNT];
+
+	/* mutex, spinlock, flag */
+	struct mutex		task_mutex;	/* for task list */
+	spinlock_t		thread_lock;	/* for cmdq hardware thread */
+	atomic_t		thread_usage;
+	spinlock_t		exec_lock;	/* for exec task */
+
+	/* suspend */
+	bool			suspended;
+
+	/* command buffer pool */
+	struct cmdq_cmd_buf	cmd_buf_pool[CMDQ_CMD_BUF_POOL_BUF_NUM];
+
+	/*
+	 * notification
+	 * wait_queue: for task done
+	 * thread_dispatch_queue: for thread acquiring
+	 */
+	wait_queue_head_t	wait_queue[CMDQ_MAX_THREAD_COUNT];
+	wait_queue_head_t	thread_dispatch_queue;
+
+	/* ccf */
+	struct clk		*clock;
+};
+
+struct cmdq_event_item {
+	enum cmdq_event	event;
+	const char	*name;
+};
+
+struct cmdq_subsys {
+	u32		base_addr;
+	int		id;
+	const char	*name;
+};
+
+static const struct cmdq_event_item cmdq_events[] = {
+	/* Display start of frame(SOF) events */
+	{CMDQ_EVENT_DISP_OVL0_SOF, "CMDQ_EVENT_DISP_OVL0_SOF"},
+	{CMDQ_EVENT_DISP_OVL1_SOF, "CMDQ_EVENT_DISP_OVL1_SOF"},
+	{CMDQ_EVENT_DISP_RDMA0_SOF, "CMDQ_EVENT_DISP_RDMA0_SOF"},
+	{CMDQ_EVENT_DISP_RDMA1_SOF, "CMDQ_EVENT_DISP_RDMA1_SOF"},
+	{CMDQ_EVENT_DISP_RDMA2_SOF, "CMDQ_EVENT_DISP_RDMA2_SOF"},
+	{CMDQ_EVENT_DISP_WDMA0_SOF, "CMDQ_EVENT_DISP_WDMA0_SOF"},
+	{CMDQ_EVENT_DISP_WDMA1_SOF, "CMDQ_EVENT_DISP_WDMA1_SOF"},
+	/* Display end of frame(EOF) events */
+	{CMDQ_EVENT_DISP_OVL0_EOF, "CMDQ_EVENT_DISP_OVL0_EOF"},
+	{CMDQ_EVENT_DISP_OVL1_EOF, "CMDQ_EVENT_DISP_OVL1_EOF"},
+	{CMDQ_EVENT_DISP_RDMA0_EOF, "CMDQ_EVENT_DISP_RDMA0_EOF"},
+	{CMDQ_EVENT_DISP_RDMA1_EOF, "CMDQ_EVENT_DISP_RDMA1_EOF"},
+	{CMDQ_EVENT_DISP_RDMA2_EOF, "CMDQ_EVENT_DISP_RDMA2_EOF"},
+	{CMDQ_EVENT_DISP_WDMA0_EOF, "CMDQ_EVENT_DISP_WDMA0_EOF"},
+	{CMDQ_EVENT_DISP_WDMA1_EOF, "CMDQ_EVENT_DISP_WDMA1_EOF"},
+	/* Mutex end of frame(EOF) events */
+	{CMDQ_EVENT_MUTEX0_STREAM_EOF, "CMDQ_EVENT_MUTEX0_STREAM_EOF"},
+	{CMDQ_EVENT_MUTEX1_STREAM_EOF, "CMDQ_EVENT_MUTEX1_STREAM_EOF"},
+	{CMDQ_EVENT_MUTEX2_STREAM_EOF, "CMDQ_EVENT_MUTEX2_STREAM_EOF"},
+	{CMDQ_EVENT_MUTEX3_STREAM_EOF, "CMDQ_EVENT_MUTEX3_STREAM_EOF"},
+	{CMDQ_EVENT_MUTEX4_STREAM_EOF, "CMDQ_EVENT_MUTEX4_STREAM_EOF"},
+	/* Display underrun events */
+	{CMDQ_EVENT_DISP_RDMA0_UNDERRUN, "CMDQ_EVENT_DISP_RDMA0_UNDERRUN"},
+	{CMDQ_EVENT_DISP_RDMA1_UNDERRUN, "CMDQ_EVENT_DISP_RDMA1_UNDERRUN"},
+	{CMDQ_EVENT_DISP_RDMA2_UNDERRUN, "CMDQ_EVENT_DISP_RDMA2_UNDERRUN"},
+	/* Keep this at the end of HW events */
+	{CMDQ_MAX_HW_EVENT_COUNT, "CMDQ_MAX_HW_EVENT_COUNT"},
+	/* This is max event and also can be used as mask. */
+	{CMDQ_SYNC_TOKEN_MAX, "CMDQ_SYNC_TOKEN_MAX"},
+	/* Invalid event */
+	{CMDQ_SYNC_TOKEN_INVALID, "CMDQ_SYNC_TOKEN_INVALID"},
+};
+
+static const struct cmdq_subsys g_subsys[] = {
+	{0x1400, 1, "DISP1"},
+	{0x1401, 2, "DISP2"},
+	{0x1402, 3, "DISP3"},
+};
+
+static int cmdq_clk_enable(struct cmdq *cqctx)
+{
+	struct device *dev = cqctx->dev;
+	int ret;
+
+	ret = clk_prepare_enable(cqctx->clock);
+	if (ret) {
+		dev_err(dev, "prepare and enable clk:%s fail\n",
+			CMDQ_CLK_NAME);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void cmdq_clk_disable(struct cmdq *cqctx)
+{
+	clk_disable_unprepare(cqctx->clock);
+}
+
+static const char *cmdq_event_get_name(enum cmdq_event event)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(cmdq_events); i++)
+		if (cmdq_events[i].event == event)
+			return cmdq_events[i].name;
+
+	return "CMDQ_EVENT_UNKNOWN";
+}
+
+static void cmdq_event_reset(struct cmdq *cqctx)
+{
+	int i;
+
+	cmdq_clk_enable(cqctx);
+
+	/* set all defined HW events to 0 */
+	for (i = 0; i < ARRAY_SIZE(cmdq_events); i++) {
+		if (cmdq_events[i].event >= CMDQ_MAX_HW_EVENT_COUNT)
+			break;
+		writel(cmdq_events[i].event,
+		       cqctx->base + CMDQ_SYNC_TOKEN_UPD_OFFSET);
+	}
+
+	cmdq_clk_disable(cqctx);
+}
+
+static int cmdq_subsys_base_addr_to_id(u32 base_addr)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(g_subsys); i++)
+		if (g_subsys[i].base_addr == base_addr)
+			return g_subsys[i].id;
+
+	return -EFAULT;
+}
+
+static u32 cmdq_subsys_id_to_base_addr(int id)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(g_subsys); i++)
+		if (g_subsys[i].id == id)
+			return g_subsys[i].base_addr;
+
+	return 0;
+}
+
+static const char *cmdq_subsys_base_addr_to_name(u32 base_addr)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(g_subsys); i++)
+		if (g_subsys[i].base_addr == base_addr)
+			return g_subsys[i].name;
+
+	return NULL;
+}
+
+static int cmdq_eng_get_thread(u64 flag)
+{
+	if (flag & BIT_ULL(CMDQ_ENG_DISP_DSI0))
+		return 0;
+	else if (flag & BIT_ULL(CMDQ_ENG_DISP_DPI0))
+		return 1;
+	else
+		return 2;
+}
+
+static const char *cmdq_event_get_module(enum cmdq_event event)
+{
+	const char *module;
+
+	switch (event) {
+	case CMDQ_EVENT_DISP_RDMA0_SOF:
+	case CMDQ_EVENT_DISP_RDMA1_SOF:
+	case CMDQ_EVENT_DISP_RDMA2_SOF:
+	case CMDQ_EVENT_DISP_RDMA0_EOF:
+	case CMDQ_EVENT_DISP_RDMA1_EOF:
+	case CMDQ_EVENT_DISP_RDMA2_EOF:
+	case CMDQ_EVENT_DISP_RDMA0_UNDERRUN:
+	case CMDQ_EVENT_DISP_RDMA1_UNDERRUN:
+	case CMDQ_EVENT_DISP_RDMA2_UNDERRUN:
+		module = "DISP_RDMA";
+		break;
+	case CMDQ_EVENT_DISP_WDMA0_SOF:
+	case CMDQ_EVENT_DISP_WDMA1_SOF:
+	case CMDQ_EVENT_DISP_WDMA0_EOF:
+	case CMDQ_EVENT_DISP_WDMA1_EOF:
+		module = "DISP_WDMA";
+		break;
+	case CMDQ_EVENT_DISP_OVL0_SOF:
+	case CMDQ_EVENT_DISP_OVL1_SOF:
+	case CMDQ_EVENT_DISP_OVL0_EOF:
+	case CMDQ_EVENT_DISP_OVL1_EOF:
+		module = "DISP_OVL";
+		break;
+	case CMDQ_EVENT_MUTEX0_STREAM_EOF ... CMDQ_EVENT_MUTEX4_STREAM_EOF:
+		module = "DISP";
+		break;
+	default:
+		module = "CMDQ";
+		break;
+	}
+
+	return module;
+}
+
+static int cmdq_cmd_buf_pool_init(struct cmdq *cqctx)
+{
+	struct device *dev = cqctx->dev;
+	int i;
+	int ret = 0;
+	struct cmdq_cmd_buf *buf;
+
+	for (i = 0; i < ARRAY_SIZE(cqctx->cmd_buf_pool); i++) {
+		buf = &cqctx->cmd_buf_pool[i];
+		buf->va = dma_alloc_coherent(dev, CMDQ_CMD_BUF_POOL_BUF_SIZE,
+					     &buf->pa, GFP_KERNEL);
+		if (!buf->va) {
+			dev_err(dev, "failed to alloc cmdq_cmd_buf\n");
+			ret = -ENOMEM;
+			goto fail_alloc;
+		}
+	}
+
+	return 0;
+
+fail_alloc:
+	for (i -= 1; i >= 0 ; i--) {
+		buf = &cqctx->cmd_buf_pool[i];
+		dma_free_coherent(dev, CMDQ_CMD_BUF_POOL_BUF_SIZE, buf->va,
+				  buf->pa);
+	}
+
+	return ret;
+}
+
+static void cmdq_cmd_buf_pool_uninit(struct cmdq *cqctx)
+{
+	struct device *dev = cqctx->dev;
+	int i;
+	struct cmdq_cmd_buf *buf;
+
+	for (i = 0; i < ARRAY_SIZE(cqctx->cmd_buf_pool); i++) {
+		buf = &cqctx->cmd_buf_pool[i];
+		dma_free_coherent(dev, CMDQ_CMD_BUF_POOL_BUF_SIZE, buf->va,
+				  buf->pa);
+		if (atomic_read(&buf->used))
+			dev_err(dev,
+				"cmdq_cmd_buf[%d] va:0x%p still in use\n",
+				i, buf->va);
+	}
+}
+
+static struct cmdq_cmd_buf *cmdq_cmd_buf_pool_get(struct cmdq *cqctx)
+{
+	int i;
+	struct cmdq_cmd_buf *buf;
+
+	for (i = 0; i < ARRAY_SIZE(cqctx->cmd_buf_pool); i++) {
+		buf = &cqctx->cmd_buf_pool[i];
+		if (!atomic_cmpxchg(&buf->used, 0, 1))
+			return buf;
+	}
+
+	return NULL;
+}
+
+static void cmdq_cmd_buf_pool_put(struct cmdq_cmd_buf *buf)
+{
+	atomic_set(&buf->used, 0);
+}
+
+static int cmdq_subsys_from_phys_addr(struct cmdq *cqctx, u32 cmdq_phys_addr)
+{
+	u32 base_addr = cmdq_phys_addr >> 16;
+	int subsys = cmdq_subsys_base_addr_to_id(base_addr);
+
+	if (subsys < 0)
+		dev_err(cqctx->dev,
+			"unknown subsys: error=%d, phys=0x%08x\n",
+			subsys, cmdq_phys_addr);
+
+	return subsys;
+}
+
+/*
+ * It's a kmemcache creator for cmdq_task to initialize variables
+ * without command buffer.
+ */
+static void cmdq_task_ctor(void *param)
+{
+	struct cmdq_task *task = param;
+
+	memset(task, 0, sizeof(*task));
+	INIT_LIST_HEAD(&task->list_entry);
+	task->task_state = TASK_STATE_IDLE;
+	task->thread = NULL;
+}
+
+static void cmdq_task_free_command_buffer(struct cmdq_task *task)
+{
+	struct cmdq *cqctx = task->cqctx;
+	struct device *dev = cqctx->dev;
+
+	if (!task->va_base)
+		return;
+
+	if (task->cmd_buf)
+		cmdq_cmd_buf_pool_put(task->cmd_buf);
+	else
+		dma_free_coherent(dev, task->buf_size, task->va_base,
+				  task->mva_base);
+
+	task->va_base = NULL;
+	task->mva_base = 0;
+	task->buf_size = 0;
+	task->command_size = 0;
+	task->num_cmd = 0;
+	task->cmd_buf = NULL;
+}
+
+/*
+ * Ensure size of command buffer in the given cmdq_task.
+ * Existing buffer data will be copied to new buffer.
+ * This buffer is guaranteed to be physically continuous.
+ * returns -ENOMEM if cannot allocate new buffer
+ */
+static int cmdq_task_realloc_command_buffer(struct cmdq_task *task, size_t size)
+{
+	struct cmdq *cqctx = task->cqctx;
+	struct device *dev = cqctx->dev;
+	void *new_buf = NULL;
+	dma_addr_t new_mva_base;
+	size_t cmd_size;
+	u32 num_cmd;
+	struct cmdq_cmd_buf *cmd_buf = NULL;
+
+	if (task->va_base && task->buf_size >= size)
+		return 0;
+
+	/* try command pool first */
+	if (size <= CMDQ_CMD_BUF_POOL_BUF_SIZE) {
+		cmd_buf = cmdq_cmd_buf_pool_get(cqctx);
+		if (cmd_buf) {
+			new_buf = cmd_buf->va;
+			new_mva_base = cmd_buf->pa;
+			memset(new_buf, 0, CMDQ_CMD_BUF_POOL_BUF_SIZE);
+		}
+	}
+
+	if (!new_buf) {
+		new_buf = dma_alloc_coherent(dev, size, &new_mva_base,
+					     GFP_KERNEL);
+		if (!new_buf) {
+			dev_err(dev, "realloc cmd buffer of size %zu failed\n",
+				size);
+			return -ENOMEM;
+		}
+	}
+
+	/* copy and release old buffer */
+	if (task->va_base)
+		memcpy(new_buf, task->va_base, task->buf_size);
+
+	/*
+	 * we should keep track of num_cmd and cmd_size
+	 * since they are cleared in free command buffer
+	 */
+	num_cmd = task->num_cmd;
+	cmd_size = task->command_size;
+	cmdq_task_free_command_buffer(task);
+
+	/* attach the new buffer */
+	task->va_base = new_buf;
+	task->mva_base = new_mva_base;
+	task->buf_size = cmd_buf ? CMDQ_CMD_BUF_POOL_BUF_SIZE : size;
+	task->num_cmd = num_cmd;
+	task->command_size = cmd_size;
+	task->cmd_buf = cmd_buf;
+
+	return 0;
+}
+
+/* allocate and initialize struct cmdq_task and its command buffer */
+static struct cmdq_task *cmdq_task_create(struct cmdq *cqctx)
+{
+	struct device *dev = cqctx->dev;
+	struct cmdq_task *task;
+	int status;
+
+	task = kmem_cache_alloc(cqctx->task_cache, GFP_KERNEL);
+	task->cqctx = cqctx;
+	status = cmdq_task_realloc_command_buffer(
+			task, CMDQ_INITIAL_CMD_BLOCK_SIZE);
+	if (status < 0) {
+		dev_err(dev, "allocate command buffer failed\n");
+		kmem_cache_free(cqctx->task_cache, task);
+		return NULL;
+	}
+	return task;
+}
+
+static int cmdq_dev_init(struct platform_device *pdev, struct cmdq *cqctx)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *node = dev->of_node;
+	struct resource *res;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	cqctx->base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(cqctx->base)) {
+		dev_err(dev, "failed to ioremap gce\n");
+		return PTR_ERR(cqctx->base);
+	}
+
+	cqctx->irq = irq_of_parse_and_map(node, 0);
+	if (!cqctx->irq) {
+		dev_err(dev, "failed to get irq\n");
+		return -EINVAL;
+	}
+
+	dev_dbg(dev, "cmdq device: addr:0x%p, va:0x%p, irq:%d\n",
+		dev, cqctx->base, cqctx->irq);
+	return 0;
+}
+
+static void cmdq_task_release_unlocked(struct cmdq_task *task)
+{
+	struct cmdq *cqctx = task->cqctx;
+
+	/* This func should be inside cqctx->task_mutex mutex */
+	lockdep_assert_held(&cqctx->task_mutex);
+
+	task->task_state = TASK_STATE_IDLE;
+	task->thread = NULL;
+
+	cmdq_task_free_command_buffer(task);
+
+	/*
+	 * move from active/waiting list to free list
+	 * todo: shrink free list
+	 */
+	list_move_tail(&task->list_entry, &cqctx->task_free_list);
+}
+
+static void cmdq_task_release_internal(struct cmdq_task *task)
+{
+	struct cmdq *cqctx = task->cqctx;
+
+	mutex_lock(&cqctx->task_mutex);
+	cmdq_task_release_unlocked(task);
+	mutex_unlock(&cqctx->task_mutex);
+}
+
+static struct cmdq_task *cmdq_core_find_free_task(struct cmdq *cqctx)
+{
+	struct cmdq_task *task;
+
+	mutex_lock(&cqctx->task_mutex);
+
+	/*
+	 * Pick from free list first;
+	 * create one if there is no free entry.
+	 */
+	if (list_empty(&cqctx->task_free_list)) {
+		task = cmdq_task_create(cqctx);
+	} else {
+		task = list_first_entry(&cqctx->task_free_list,
+					struct cmdq_task, list_entry);
+		/* remove from free list */
+		list_del_init(&task->list_entry);
+	}
+
+	mutex_unlock(&cqctx->task_mutex);
+
+	return task;
+}
+
+/* After dropping error task, we have to reorder remaining valid tasks. */
+static void cmdq_thread_reorder_task_array(struct cmdq_thread *thread,
+					   int prev_id)
+{
+	int i, j;
+	int next_id, search_id;
+	int reorder_count = 0;
+	struct cmdq_task *task;
+	u32 *task_base;
+
+	next_id = prev_id + 1;
+	for (i = 1; i < (CMDQ_MAX_TASK_IN_THREAD - 1); i++, next_id++) {
+		if (next_id >= CMDQ_MAX_TASK_IN_THREAD)
+			next_id = 0;
+
+		if (thread->cur_task[next_id])
+			break;
+
+		search_id = next_id + 1;
+		for (j = (i + 1); j < CMDQ_MAX_TASK_IN_THREAD;
+		     j++, search_id++) {
+			if (search_id >= CMDQ_MAX_TASK_IN_THREAD)
+				search_id = 0;
+
+			if (thread->cur_task[search_id]) {
+				thread->cur_task[next_id] =
+					thread->cur_task[search_id];
+				thread->cur_task[search_id] = NULL;
+				if ((j - i) > reorder_count)
+					reorder_count = j - i;
+
+				break;
+			}
+		}
+
+		task = thread->cur_task[next_id];
+		task_base = task->va_base;
+		if ((task_base[task->num_cmd - 1] == CMDQ_JUMP_BY_OFFSET) &&
+		    (task_base[task->num_cmd - 2] == CMDQ_JUMP_TO_BEGIN)) {
+			/* We reached the last task */
+			break;
+		}
+	}
+
+	thread->next_cookie -= reorder_count;
+}
+
+static int cmdq_core_sync_command(struct cmdq_task *task,
+				  struct cmdq_command *cmd_desc)
+{
+	struct cmdq *cqctx = task->cqctx;
+	struct device *dev = cqctx->dev;
+	int status;
+	size_t size;
+
+	size = task->command_size + CMDQ_INST_SIZE;
+	status = cmdq_task_realloc_command_buffer(task, size);
+	if (status < 0) {
+		dev_err(dev, "failed to realloc command buffer\n");
+		dev_err(dev, "task=0x%p, request size=%zu\n", task, size);
+		return status;
+	}
+
+	/* copy the commands to our DMA buffer */
+	memcpy(task->va_base, cmd_desc->base, cmd_desc->size);
+
+	/* re-adjust num_cmd according to command_size */
+	task->num_cmd = task->command_size / sizeof(u32);
+
+	return 0;
+}
+
+static struct cmdq_task *cmdq_core_acquire_task(struct cmdq_command *cmd_desc,
+						struct cmdq_task_cb *cb)
+{
+	struct cmdq *cqctx = cmd_desc->cqctx;
+	struct device *dev = cqctx->dev;
+	struct cmdq_task *task;
+
+	task = cmdq_core_find_free_task(cqctx);
+	if (!task) {
+		dev_err(dev, "can't acquire task info\n");
+		return NULL;
+	}
+
+	/* initialize field values */
+	task->engine_flag = cmd_desc->engine_flag;
+	task->task_state = TASK_STATE_WAITING;
+	task->reorder = 0;
+	task->thread = NULL;
+	task->irq_flag = 0x0;
+	task->cb = *cb;
+	task->command_size = cmd_desc->size;
+
+	if (cmdq_core_sync_command(task, cmd_desc) < 0) {
+		dev_err(dev, "fail to sync command\n");
+		cmdq_task_release_internal(task);
+		return NULL;
+	}
+
+	/* insert into waiting list to process */
+	if (task) {
+		task->submit = ktime_get();
+		mutex_lock(&cqctx->task_mutex);
+		list_add_tail(&task->list_entry, &cqctx->task_wait_list);
+		mutex_unlock(&cqctx->task_mutex);
+	}
+
+	return task;
+}
+
+static void cmdq_thread_writel(struct cmdq_thread *thread, u32 value,
+			       u32 offset)
+{
+	writel(value, thread->base + offset);
+}
+
+static u32 cmdq_thread_readl(struct cmdq_thread *thread, u32 offset)
+{
+	return readl(thread->base + offset);
+}
+
+static u32 cmdq_thread_get_cookie(struct cmdq_thread *thread)
+{
+	return cmdq_thread_readl(thread, CMDQ_THR_EXEC_CNT_OFFSET) &
+			CMDQ_COOKIE_MASK;
+}
+
+static struct cmdq_thread *cmdq_thread_get(struct cmdq *cqctx, u64 flag)
+{
+	int tid = cmdq_eng_get_thread(flag);
+	struct cmdq_thread *thread = &cqctx->thread[tid];
+	u32 next_cookie;
+
+	/* make sure the found thread has enough space for the task */
+	if (thread->task_count >= CMDQ_MAX_TASK_IN_THREAD)
+		return NULL;
+
+	next_cookie = thread->next_cookie % CMDQ_MAX_TASK_IN_THREAD;
+	if (thread->cur_task[next_cookie])
+		return NULL;
+
+	cmdq_clk_enable(cqctx);
+	atomic_inc(&cqctx->thread_usage);
+	return thread;
+}
+
+static void cmdq_thread_put(struct cmdq *cqctx, struct cmdq_thread *thread)
+{
+	if (WARN_ON(thread == NULL))
+		return;
+
+	cmdq_clk_disable(cqctx);
+	atomic_dec(&cqctx->thread_usage);
+}
+
+static int cmdq_thread_suspend(struct cmdq *cqctx, struct cmdq_thread *thread)
+{
+	u32 enabled;
+	u32 status;
+
+	/* write suspend bit */
+	cmdq_thread_writel(thread, CMDQ_THR_SUSPEND,
+			   CMDQ_THR_SUSPEND_TASK_OFFSET);
+
+	/* If already disabled, treat as suspended successful. */
+	enabled = cmdq_thread_readl(thread, CMDQ_THR_ENABLE_TASK_OFFSET);
+	if (!(enabled & CMDQ_THR_ENABLED))
+		return 0;
+
+	/* poll suspended status */
+	if (readl_poll_timeout_atomic(thread->base +
+				      CMDQ_THR_CURR_STATUS_OFFSET,
+				      status,
+				      status & CMDQ_THR_STATUS_SUSPENDED,
+				      0, 10)) {
+		dev_err(cqctx->dev, "Suspend HW thread %d failed\n",
+			thread->id);
+		return -EFAULT;
+	}
+
+	return 0;
+}
+
+static void cmdq_thread_resume(struct cmdq_thread *thread)
+{
+	cmdq_thread_writel(thread, CMDQ_THR_RESUME,
+			   CMDQ_THR_SUSPEND_TASK_OFFSET);
+}
+
+static int cmdq_thread_reset(struct cmdq *cqctx, struct cmdq_thread *thread)
+{
+	void __iomem *gce_base = cqctx->base;
+	u32 warm_reset;
+
+	cmdq_thread_writel(thread, CMDQ_THR_WARM_RESET,
+			   CMDQ_THR_WARM_RESET_OFFSET);
+
+	if (readl_poll_timeout_atomic(thread->base + CMDQ_THR_WARM_RESET_OFFSET,
+				      warm_reset,
+				      !(warm_reset & CMDQ_THR_WARM_RESET),
+				      0, 10)) {
+		dev_err(cqctx->dev, "Reset HW thread %d failed\n", thread->id);
+		return -EFAULT;
+	}
+
+	writel(CMDQ_THR_SLOT_CYCLES, gce_base + CMDQ_THR_SLOT_CYCLES_OFFSET);
+	return 0;
+}
+
+static int cmdq_thread_disable(struct cmdq *cqctx, struct cmdq_thread *thread)
+{
+	cmdq_thread_reset(cqctx, thread);
+	cmdq_thread_writel(thread, CMDQ_THR_DISABLED,
+			   CMDQ_THR_ENABLE_TASK_OFFSET);
+	return 0;
+}
+
+static u32 *cmdq_task_get_pc_and_inst(const struct cmdq_task *task,
+				      u32 insts[2])
+{
+	struct cmdq *cqctx = task->cqctx;
+	struct cmdq_thread *thread = task->thread;
+	unsigned long pc_pa;
+	void *pc_va, *cmd_end;
+
+	memset(insts, 0, sizeof(u32) * 2);
+
+	if (!task->va_base) {
+		dev_err(cqctx->dev, "get pc failed since invalid param,\n");
+		dev_err(cqctx->dev, "task:0x%p, task->va_base:0x%p, thread:%d\n",
+			task, task->va_base, thread->id);
+		return NULL;
+	}
+
+	pc_pa = cmdq_thread_readl(thread, CMDQ_THR_CURR_ADDR_OFFSET);
+	pc_va = task->va_base + (pc_pa - task->mva_base);
+	cmd_end = task->va_base + task->command_size - sizeof(u32);
+
+	if (task->va_base <= pc_va && pc_va <= cmd_end) {
+		if (pc_va < cmd_end) {
+			/* get arg_a and arg_b */
+			insts[0] = readl(pc_va);
+			insts[1] = readl(pc_va + 4);
+		} else {
+			/* get arg_a and arg_b of previous cmd */
+			insts[0] = readl(pc_va - 8);
+			insts[1] = readl(pc_va - 4);
+		}
+	} else {
+		return NULL;
+	}
+
+	return (u32 *)pc_va;
+}
+
+static const char *cmdq_core_parse_module_from_subsys(u32 arg_a)
+{
+	int id = (arg_a & CMDQ_ARG_A_SUBSYS_MASK) >> CMDQ_SUBSYS_SHIFT;
+	u32 base_addr = cmdq_subsys_id_to_base_addr(id);
+	const char *module = cmdq_subsys_base_addr_to_name(base_addr);
+
+	return module ? module : "CMDQ";
+}
+
+static const char *cmdq_core_parse_op(u32 op_code)
+{
+	switch (op_code) {
+	case CMDQ_CODE_WRITE:
+		return "WRIT";
+	case CMDQ_CODE_WFE:
+		return "WFE ";
+	case CMDQ_CODE_MOVE:
+		return "MOVE";
+	case CMDQ_CODE_JUMP:
+		return "JUMP";
+	case CMDQ_CODE_EOC:
+		return "EOC ";
+	}
+	return NULL;
+}
+
+static void cmdq_core_parse_error(struct cmdq_task *task,
+				  const char **module_name, int *flag,
+				  u32 *inst_a, u32 *inst_b)
+{
+	int irq_flag = task->irq_flag;
+	u32 insts[2] = { 0 };
+	const char *module;
+
+	/*
+	 * other cases, use instruction to judge
+	 * because engine flag are not sufficient
+	 */
+	if (cmdq_task_get_pc_and_inst(task, insts)) {
+		u32 op, arg_a, arg_b;
+
+		op = insts[1] >> CMDQ_OP_CODE_SHIFT;
+		arg_a = insts[1] & CMDQ_ARG_A_MASK;
+		arg_b = insts[0];
+
+		switch (op) {
+		case CMDQ_CODE_WRITE:
+			module = cmdq_core_parse_module_from_subsys(arg_a);
+			break;
+		case CMDQ_CODE_WFE:
+			/* arg_a is the event id */
+			module = cmdq_event_get_module((enum cmdq_event)arg_a);
+			break;
+		case CMDQ_CODE_MOVE:
+		case CMDQ_CODE_JUMP:
+		case CMDQ_CODE_EOC:
+		default:
+			module = "CMDQ";
+			break;
+		}
+	} else {
+		module = "CMDQ";
+	}
+
+	/* fill output parameter */
+	*module_name = module;
+	*flag = irq_flag;
+	*inst_a = insts[1];
+	*inst_b = insts[0];
+}
+
+static void cmdq_thread_insert_task_by_cookie(struct cmdq_thread *thread,
+					      struct cmdq_task *task,
+					      int cookie)
+{
+	thread->wait_cookie = cookie;
+	thread->next_cookie = cookie + 1;
+	if (thread->next_cookie > CMDQ_MAX_COOKIE_VALUE)
+		thread->next_cookie = 0;
+
+	/* first task, so set to 1 */
+	thread->task_count = 1;
+
+	thread->cur_task[cookie % CMDQ_MAX_TASK_IN_THREAD] = task;
+}
+
+static int cmdq_thread_remove_task_by_index(struct cmdq_thread *thread,
+					    int index,
+					    enum cmdq_task_state new_state)
+{
+	struct cmdq_task *task;
+	struct device *dev;
+
+	task = thread->cur_task[index];
+	if (!task) {
+		pr_err("%s: remove fail, task:%d on thread:0x%p is NULL\n",
+		       __func__, index, thread);
+		return -EINVAL;
+	}
+	dev = task->cqctx->dev;
+
+	/*
+	 * note timing to switch a task to done_status(_ERROR, _KILLED, _DONE)
+	 * is aligned with thread's taskcount change
+	 * check task status to prevent double clean-up thread's taskcount
+	 */
+	if (task->task_state != TASK_STATE_BUSY) {
+		dev_err(dev, "remove task failed\n");
+		dev_err(dev, "state:%d. thread:%d, task:%d, new_state:%d\n",
+			task->task_state, thread->id, index, new_state);
+		return -EINVAL;
+	}
+
+	if (thread->task_count == 0) {
+		dev_err(dev, "no task to remove\n");
+		dev_err(dev, "thread:%d, index:%d\n", thread->id, index);
+		return -EINVAL;
+	}
+
+	task->task_state = new_state;
+	thread->cur_task[index] = NULL;
+	thread->task_count--;
+
+	return 0;
+}
+
+static int cmdq_thread_force_remove_task(struct cmdq_task *task)
+{
+	struct cmdq *cqctx = task->cqctx;
+	struct cmdq_thread *thread = task->thread;
+	int status;
+	int cookie;
+	struct cmdq_task *exec_task;
+
+	status = cmdq_thread_suspend(cqctx, thread);
+
+	cmdq_thread_writel(thread, CMDQ_THR_NO_TIMEOUT,
+			   CMDQ_THR_INST_CYCLES_OFFSET);
+
+	/* The cookie of the task currently being processed */
+	cookie = cmdq_thread_get_cookie(thread) + 1;
+
+	exec_task = thread->cur_task[cookie % CMDQ_MAX_TASK_IN_THREAD];
+	if (exec_task == task) {
+		dma_addr_t eoc_pa = task->mva_base + task->command_size - 16;
+
+		/* The task is executed now, set the PC to EOC for bypass */
+		cmdq_thread_writel(thread, eoc_pa, CMDQ_THR_CURR_ADDR_OFFSET);
+
+		thread->cur_task[cookie % CMDQ_MAX_TASK_IN_THREAD] = NULL;
+		task->task_state = TASK_STATE_KILLED;
+	} else {
+		int i, j;
+		u32 *task_base, *exec_task_base;
+
+		j = thread->task_count;
+		for (i = cookie; j > 0; j--, i++) {
+			i %= CMDQ_MAX_TASK_IN_THREAD;
+
+			exec_task = thread->cur_task[i];
+			if (!exec_task)
+				continue;
+
+			task_base = task->va_base;
+			exec_task_base = exec_task->va_base;
+			if ((exec_task_base[exec_task->num_cmd - 1] ==
+			     CMDQ_JUMP_BY_OFFSET) &&
+			    (exec_task_base[exec_task->num_cmd - 2] ==
+			     CMDQ_JUMP_TO_BEGIN)) {
+				/* reached the last task */
+				break;
+			}
+
+			if (exec_task_base[exec_task->num_cmd - 2] ==
+			    task->mva_base) {
+				/* fake EOC command */
+				exec_task_base[exec_task->num_cmd - 2] =
+					CMDQ_EOC_IRQ_EN;
+				exec_task_base[exec_task->num_cmd - 1] =
+					CMDQ_CODE_EOC << CMDQ_OP_CODE_SHIFT;
+
+				/* bypass the task */
+				exec_task_base[exec_task->num_cmd] =
+					task_base[task->num_cmd - 2];
+				exec_task_base[exec_task->num_cmd + 1] =
+					task_base[task->num_cmd - 1];
+
+				i = (i + 1) % CMDQ_MAX_TASK_IN_THREAD;
+
+				thread->cur_task[i] = NULL;
+				task->task_state = TASK_STATE_KILLED;
+				status = 0;
+				break;
+			}
+		}
+	}
+
+	return status;
+}
+
+static struct cmdq_task *cmdq_thread_search_task_by_pc(
+		const struct cmdq_thread *thread, u32 pc)
+{
+	struct cmdq_task *task;
+	int i;
+
+	for (i = 0; i < CMDQ_MAX_TASK_IN_THREAD; i++) {
+		task = thread->cur_task[i];
+		if (task &&
+		    pc >= task->mva_base &&
+		    pc <= task->mva_base + task->command_size)
+			break;
+	}
+
+	return task;
+}
+
+/*
+ * Re-fetch thread's command buffer
+ * Use Case:
+ *     If SW modifies command buffer content after SW configed commands to GCE,
+ *     SW should notify GCE to re-fetch commands in order to
+ *     prevent inconsistent command buffer content between DRAM and GCE's SRAM.
+ */
+static void cmdq_core_invalidate_hw_fetched_buffer(struct cmdq *cqctx,
+						   struct cmdq_thread *thread)
+{
+	u32 pc;
+
+	/*
+	 * Setting HW thread PC will invoke that
+	 * GCE (CMDQ HW) gives up fetched command buffer,
+	 * and fetch command from DRAM to GCE's SRAM again.
+	 */
+	pc = cmdq_thread_readl(thread, CMDQ_THR_CURR_ADDR_OFFSET);
+	cmdq_thread_writel(thread, pc, CMDQ_THR_CURR_ADDR_OFFSET);
+}
+
+static int cmdq_task_insert_into_thread(struct cmdq_task *task, int loop)
+{
+	struct cmdq *cqctx = task->cqctx;
+	struct device *dev = cqctx->dev;
+	struct cmdq_thread *thread = task->thread;
+	struct cmdq_task *prev_task;
+	int index, prev;
+	u32 *prev_task_base;
+
+	/* find previous task and then link this task behind it */
+
+	index = thread->next_cookie % CMDQ_MAX_TASK_IN_THREAD;
+	prev = (index + CMDQ_MAX_TASK_IN_THREAD - 1) % CMDQ_MAX_TASK_IN_THREAD;
+
+	prev_task = thread->cur_task[prev];
+
+	/* maybe the job is killed, search a new one */
+	for (; !prev_task && loop > 1; loop--) {
+		dev_err(dev,
+			"prev_task is NULL, prev:%d, loop:%d, index:%d\n",
+			prev, loop, index);
+
+		prev--;
+		if (prev < 0)
+			prev = CMDQ_MAX_TASK_IN_THREAD - 1;
+
+		prev_task = thread->cur_task[prev];
+	}
+
+	if (!prev_task) {
+		dev_err(dev,
+			"invalid prev_task index:%d, loop:%d\n",
+			index, loop);
+		return -EFAULT;
+	}
+
+	/* insert this task */
+	thread->cur_task[index] = task;
+	/* let previous task jump to this new task */
+	prev_task_base = prev_task->va_base;
+	prev_task_base[prev_task->num_cmd - 1] = CMDQ_JUMP_BY_PA;
+	prev_task_base[prev_task->num_cmd - 2] = task->mva_base;
+
+	/* re-fetch command buffer again. */
+	cmdq_core_invalidate_hw_fetched_buffer(cqctx, thread);
+
+	return 0;
+}
+
+static int cmdq_task_exec_async_impl(struct cmdq_task *task,
+				     struct cmdq_thread *thread)
+{
+	struct cmdq *cqctx = task->cqctx;
+	struct device *dev = cqctx->dev;
+	int status;
+	unsigned long flags;
+	int loop;
+	int minimum;
+	int cookie;
+
+	status = 0;
+
+	spin_lock_irqsave(&cqctx->exec_lock, flags);
+
+	/* update task's thread info */
+	task->thread = thread;
+	task->irq_flag = 0;
+	task->task_state = TASK_STATE_BUSY;
+
+	if (thread->task_count <= 0) {
+		if (cmdq_thread_reset(cqctx, thread) < 0) {
+			spin_unlock_irqrestore(&cqctx->exec_lock, flags);
+			return -EFAULT;
+		}
+
+		cmdq_thread_writel(thread, CMDQ_THR_NO_TIMEOUT,
+				   CMDQ_THR_INST_CYCLES_OFFSET);
+		cmdq_thread_writel(thread, task->mva_base,
+				   CMDQ_THR_CURR_ADDR_OFFSET);
+		cmdq_thread_writel(thread, task->mva_base + task->command_size,
+				   CMDQ_THR_END_ADDR_OFFSET);
+		cmdq_thread_writel(thread, CMDQ_THR_PRIORITY,
+				   CMDQ_THR_CFG_OFFSET);
+		cmdq_thread_writel(thread, CMDQ_THR_IRQ_EN,
+				   CMDQ_THR_IRQ_ENABLE_OFFSET);
+
+		minimum = cmdq_thread_get_cookie(thread);
+		cmdq_thread_insert_task_by_cookie(
+				thread, task, (minimum + 1));
+
+		/* enable HW thread */
+		cmdq_thread_writel(thread, CMDQ_THR_ENABLED,
+				   CMDQ_THR_ENABLE_TASK_OFFSET);
+	} else {
+		unsigned long curr_pa, end_pa;
+
+		status = cmdq_thread_suspend(cqctx, thread);
+		if (status < 0) {
+			spin_unlock_irqrestore(&cqctx->exec_lock, flags);
+			return status;
+		}
+
+		cmdq_thread_writel(thread, CMDQ_THR_NO_TIMEOUT,
+				   CMDQ_THR_INST_CYCLES_OFFSET);
+
+		cookie = thread->next_cookie;
+
+		/*
+		 * Boundary case tested: EOC have been executed,
+		 *                       but JUMP is not executed
+		 * Thread PC: 0x9edc0dd8, End: 0x9edc0de0,
+		 * Curr Cookie: 1, Next Cookie: 2
+		 * PC = END - 8, EOC is executed
+		 * PC = END - 0, All CMDs are executed
+		 */
+
+		curr_pa = cmdq_thread_readl(thread, CMDQ_THR_CURR_ADDR_OFFSET);
+		end_pa = cmdq_thread_readl(thread, CMDQ_THR_END_ADDR_OFFSET);
+		if ((curr_pa == end_pa - 8) || (curr_pa == end_pa - 0)) {
+			/* set to task directly */
+			cmdq_thread_writel(thread, task->mva_base,
+					   CMDQ_THR_CURR_ADDR_OFFSET);
+			cmdq_thread_writel(thread,
+					   task->mva_base + task->command_size,
+					   CMDQ_THR_END_ADDR_OFFSET);
+			thread->cur_task[cookie % CMDQ_MAX_TASK_IN_THREAD] = task;
+			thread->task_count++;
+		} else {
+			/* Current task that shuld be processed */
+			minimum = cmdq_thread_get_cookie(thread) + 1;
+			if (minimum > CMDQ_MAX_COOKIE_VALUE)
+				minimum = 0;
+
+			/* Calculate loop count to adjust the tasks' order */
+			if (minimum <= cookie)
+				loop = cookie - minimum;
+			else
+				/* Counter wrapped */
+				loop = (CMDQ_MAX_COOKIE_VALUE - minimum + 1) +
+				       cookie;
+
+			if (loop < 0) {
+				dev_err(dev, "reorder fail:\n");
+				dev_err(dev, "  task count=%d\n", loop);
+				dev_err(dev, "  thread=%d\n", thread->id);
+				dev_err(dev, "  next cookie=%d\n",
+					thread->next_cookie);
+				dev_err(dev, "  (HW) next cookie=%d\n",
+					minimum);
+				dev_err(dev, "  task=0x%p\n", task);
+
+				spin_unlock_irqrestore(&cqctx->exec_lock,
+						       flags);
+				return -EFAULT;
+			}
+
+			if (loop > CMDQ_MAX_TASK_IN_THREAD)
+				loop %= CMDQ_MAX_TASK_IN_THREAD;
+
+			status = cmdq_task_insert_into_thread(task, loop);
+			if (status < 0) {
+				spin_unlock_irqrestore(
+						&cqctx->exec_lock, flags);
+				dev_err(dev,
+					"invalid task state for reorder.\n");
+				return status;
+			}
+
+			smp_mb(); /* modify jump before enable thread */
+
+			cmdq_thread_writel(thread,
+					   task->mva_base + task->command_size,
+					   CMDQ_THR_END_ADDR_OFFSET);
+			thread->task_count++;
+		}
+
+		thread->next_cookie++;
+		if (thread->next_cookie > CMDQ_MAX_COOKIE_VALUE)
+			thread->next_cookie = 0;
+
+		/* resume HW thread */
+		cmdq_thread_resume(thread);
+	}
+
+	spin_unlock_irqrestore(&cqctx->exec_lock, flags);
+
+	return status;
+}
+
+static void cmdq_core_handle_error(struct cmdq *cqctx,
+				   struct cmdq_thread *thread, int value)
+{
+	struct device *dev = cqctx->dev;
+	struct cmdq_task *task;
+	int cookie;
+	int count;
+	int inner;
+	int status;
+	u32 curr_pa, end_pa;
+
+	curr_pa = cmdq_thread_readl(thread, CMDQ_THR_CURR_ADDR_OFFSET);
+	end_pa = cmdq_thread_readl(thread, CMDQ_THR_END_ADDR_OFFSET);
+
+	dev_err(dev, "IRQ: error thread=%d, flag=0x%x\n", thread->id, value);
+	dev_err(dev, "IRQ: Thread PC: 0x%08x, End PC:0x%08x\n",
+		curr_pa, end_pa);
+
+	cookie = cmdq_thread_get_cookie(thread);
+
+	/*
+	 * we assume error happens BEFORE EOC
+	 * because it wouldn't be error if this interrupt is issue by EOC.
+	 * so we should inc by 1 to locate "current" task
+	 */
+	cookie++;
+
+	/* set the issued task to error state */
+	if (thread->cur_task[cookie % CMDQ_MAX_TASK_IN_THREAD]) {
+		task = thread->cur_task[cookie % CMDQ_MAX_TASK_IN_THREAD];
+		task->irq_flag = value;
+		cmdq_thread_remove_task_by_index(
+				thread, cookie % CMDQ_MAX_TASK_IN_THREAD,
+				TASK_STATE_ERROR);
+	} else {
+		dev_err(dev,
+			"IRQ: can not find task in %s, pc:0x%08x, end_pc:0x%08x\n",
+			__func__, curr_pa, end_pa);
+		if (thread->task_count <= 0) {
+			/*
+			 * suspend HW thread first,
+			 * so that we work in a consistent state
+			 * outer function should acquire spinlock:
+			 *   cqctx->exec_lock
+			 */
+			status = cmdq_thread_suspend(cqctx, thread);
+			if (status < 0)
+				dev_err(dev, "IRQ: suspend HW thread failed!");
+
+			cmdq_thread_disable(cqctx, thread);
+			dev_err(dev,
+				"IRQ: there is no task for thread (%d) %s\n",
+				thread->id, __func__);
+		}
+	}
+
+	/* set the remain tasks to done state */
+	if (thread->wait_cookie <= cookie) {
+		count = cookie - thread->wait_cookie + 1;
+	} else if ((cookie + 1) % CMDQ_MAX_COOKIE_VALUE ==
+			thread->wait_cookie) {
+		count = 0;
+	} else {
+		/* counter wrapped */
+		count = (CMDQ_MAX_COOKIE_VALUE - thread->wait_cookie + 1) +
+			(cookie + 1);
+		dev_err(dev,
+			"IRQ: counter wrapped: wait cookie:%d, hw cookie:%d, count=%d",
+			thread->wait_cookie, cookie, count);
+	}
+
+	for (inner = (thread->wait_cookie % CMDQ_MAX_TASK_IN_THREAD); count > 0;
+	     count--, inner++) {
+		if (inner >= CMDQ_MAX_TASK_IN_THREAD)
+			inner = 0;
+
+		if (thread->cur_task[inner]) {
+			task = thread->cur_task[inner];
+			task->irq_flag = 0;	/* don't know irq flag */
+			/* still call isr_cb to prevent lock */
+			if (task->cb.isr_cb)
+				task->cb.isr_cb(task->cb.isr_data);
+			cmdq_thread_remove_task_by_index(
+					thread, inner, TASK_STATE_DONE);
+		}
+	}
+
+	thread->wait_cookie = cookie + 1;
+	if (thread->wait_cookie > CMDQ_MAX_COOKIE_VALUE)
+		thread->wait_cookie -= (CMDQ_MAX_COOKIE_VALUE + 1);
+			/* min cookie value is 0 */
+
+	wake_up(&cqctx->wait_queue[thread->id]);
+}
+
+static void cmdq_core_handle_done(struct cmdq *cqctx,
+				  struct cmdq_thread *thread, int value)
+{
+	struct device *dev = cqctx->dev;
+	int cookie = cmdq_thread_get_cookie(thread);
+	int count;
+	int i;
+	struct cmdq_task *task;
+
+	if (thread->wait_cookie <= cookie) {
+		count = cookie - thread->wait_cookie + 1;
+	} else if ((cookie + 1) % CMDQ_MAX_COOKIE_VALUE ==
+			thread->wait_cookie) {
+		count = 0;
+	} else {
+		/* counter wrapped */
+		count = (CMDQ_MAX_COOKIE_VALUE - thread->wait_cookie + 1) +
+			(cookie + 1);
+		dev_err(dev,
+			"IRQ: counter wrapped: wait cookie:%d, hw cookie:%d, count=%d",
+			thread->wait_cookie, cookie, count);
+	}
+
+	for (i = (thread->wait_cookie % CMDQ_MAX_TASK_IN_THREAD); count > 0;
+	     count--, i++) {
+		if (i >= CMDQ_MAX_TASK_IN_THREAD)
+			i = 0;
+
+		if (thread->cur_task[i]) {
+			task = thread->cur_task[i];
+			task->irq_flag = value;
+			if (task->cb.isr_cb)
+				task->cb.isr_cb(task->cb.isr_data);
+			cmdq_thread_remove_task_by_index(
+					thread, i, TASK_STATE_DONE);
+		}
+	}
+
+	thread->wait_cookie = cookie + 1;
+	if (thread->wait_cookie > CMDQ_MAX_COOKIE_VALUE)
+		thread->wait_cookie -= (CMDQ_MAX_COOKIE_VALUE + 1);
+			/* min cookie value is 0 */
+
+	wake_up(&cqctx->wait_queue[thread->id]);
+}
+
+static void cmdq_core_handle_irq(struct cmdq *cqctx, int tid)
+{
+	struct device *dev = cqctx->dev;
+	struct cmdq_thread *thread = &cqctx->thread[tid];
+	unsigned long flags = 0L;
+	int value;
+	int enabled;
+
+	/*
+	 * normal execution, marks tasks done and remove from thread
+	 * also, handle "loop CB fail" case
+	 */
+	spin_lock_irqsave(&cqctx->exec_lock, flags);
+
+	/*
+	 * it is possible for another CPU core
+	 * to run "release task" right before we acquire the spin lock
+	 * and thus reset / disable this HW thread
+	 * so we check both the IRQ flag and the enable bit of this thread
+	 */
+	value = cmdq_thread_readl(thread, CMDQ_THR_IRQ_STATUS_OFFSET);
+	if (!(value & CMDQ_THR_IRQ_MASK)) {
+		dev_err(dev,
+			"IRQ: thread %d got interrupt but IRQ flag is 0x%08x\n",
+			thread->id, value);
+		spin_unlock_irqrestore(&cqctx->exec_lock, flags);
+		return;
+	}
+
+	enabled = cmdq_thread_readl(thread, CMDQ_THR_ENABLE_TASK_OFFSET);
+	if (!(enabled & CMDQ_THR_ENABLED)) {
+		dev_err(dev,
+			"IRQ: thread %d got interrupt already disabled 0x%08x\n",
+			thread->id, enabled);
+		spin_unlock_irqrestore(&cqctx->exec_lock, flags);
+		return;
+	}
+
+	/*
+	 * Move the reset IRQ before read HW cookie
+	 * to prevent race condition and save the cost of suspend
+	 */
+	cmdq_thread_writel(thread, ~value, CMDQ_THR_IRQ_STATUS_OFFSET);
+
+	if (value & CMDQ_THR_IRQ_ERROR)
+		cmdq_core_handle_error(cqctx, thread, value);
+	else if (value & CMDQ_THR_IRQ_DONE)
+		cmdq_core_handle_done(cqctx, thread, value);
+
+	spin_unlock_irqrestore(&cqctx->exec_lock, flags);
+}
+
+static int cmdq_core_resumed_notifier(struct cmdq *cqctx)
+{
+	unsigned long flags = 0L;
+
+	cmdq_event_reset(cqctx);
+
+	spin_lock_irqsave(&cqctx->thread_lock, flags);
+	cqctx->suspended = false;
+
+	/*
+	 * during suspending, there may be queued tasks.
+	 * we should process them if any.
+	 */
+	queue_work(cqctx->task_consume_wq,
+		   &cqctx->task_consume_wait_queue_item);
+
+	spin_unlock_irqrestore(&cqctx->thread_lock, flags);
+
+	return 0;
+}
+
+static int cmdq_task_exec_async(struct cmdq_task *task,
+				struct cmdq_thread *thread)
+{
+	struct device *dev = task->cqctx->dev;
+	int status;
+
+	status = cmdq_task_exec_async_impl(task, thread);
+	if (status >= 0)
+		return status;
+
+	if ((task->task_state == TASK_STATE_KILLED) ||
+	    (task->task_state == TASK_STATE_ERROR)) {
+		dev_err(dev, "cmdq_task_exec_async_impl fail\n");
+		return -EFAULT;
+	}
+
+	return 0;
+}
+
+static void cmdq_core_consume_waiting_list(struct work_struct *work)
+{
+	struct list_head *p, *n = NULL;
+	bool thread_acquired;
+	ktime_t consume_time;
+	s64 waiting_time_ns;
+	bool need_log;
+	struct cmdq *cqctx = container_of(work, struct cmdq,
+					  task_consume_wait_queue_item);
+	struct device *dev = cqctx->dev;
+
+	/*
+	 * when we're suspending,
+	 * do not execute any tasks. delay & hold them.
+	 */
+	if (cqctx->suspended)
+		return;
+
+	consume_time = ktime_get();
+
+	mutex_lock(&cqctx->task_mutex);
+
+	thread_acquired = false;
+
+	/* scan and remove (if executed) waiting tasks */
+	list_for_each_safe(p, n, &cqctx->task_wait_list) {
+		struct cmdq_task *task;
+		struct cmdq_thread *thread = NULL;
+		int status;
+
+		task = list_entry(p, struct cmdq_task, list_entry);
+
+		waiting_time_ns = ktime_to_ns(
+				ktime_sub(consume_time, task->submit));
+		need_log = waiting_time_ns >= CMDQ_PREALARM_TIMEOUT_NS;
+		/* acquire HW thread */
+		thread = cmdq_thread_get(cqctx, task->engine_flag);
+		if (!thread) {
+			/* have to wait, remain in wait list */
+			dev_warn(dev, "acquire thread fail, need to wait\n");
+			if (need_log) /* task wait too long */
+				dev_warn(dev, "waiting:%lldns, task:0x%p\n",
+					 waiting_time_ns, task);
+			continue;
+		}
+
+		/* some task is ready to run */
+		thread_acquired = true;
+
+		/*
+		 * start execution
+		 * remove from wait list and put into active list
+		 */
+		list_move_tail(&task->list_entry,
+			       &cqctx->task_active_list);
+
+		/* run task on thread */
+		status = cmdq_task_exec_async(task, thread);
+		if (status < 0) {
+			dev_err(dev, "%s fail, release task 0x%p\n",
+				__func__, task);
+			cmdq_thread_put(cqctx, thread);
+			task->thread = NULL;
+			cmdq_task_release_unlocked(task);
+			task = NULL;
+		}
+	}
+
+	if (thread_acquired) {
+		/*
+		 * notify some task's sw thread to change their waiting state.
+		 * (if they have already called cmdq_task_wait_and_release())
+		 */
+		wake_up_all(&cqctx->thread_dispatch_queue);
+	}
+
+	mutex_unlock(&cqctx->task_mutex);
+}
+
+static int cmdq_core_submit_task_async(struct cmdq_command *cmd_desc,
+				       struct cmdq_task **task_out,
+				       struct cmdq_task_cb *cb)
+{
+	struct cmdq *cqctx = cmd_desc->cqctx;
+
+	/* creates a new task and put into tail of waiting list */
+	*task_out = cmdq_core_acquire_task(cmd_desc, cb);
+
+	if (!(*task_out))
+		return -EFAULT;
+
+	/*
+	 * Consume the waiting list.
+	 * This may or may not execute the task, depending on available threads.
+	 */
+	cmdq_core_consume_waiting_list(&cqctx->task_consume_wait_queue_item);
+
+	return 0;
+}
+
+static int cmdq_core_release_task(struct cmdq_task *task)
+{
+	struct cmdq *cqctx = task->cqctx;
+	struct cmdq_thread *thread = task->thread;
+	unsigned long flags;
+	int status;
+
+	if (thread) {
+		/* this task is being executed (or queueed) on a hw thread */
+
+		/* get sw lock first to ensure atomic access hw */
+		spin_lock_irqsave(&cqctx->exec_lock, flags);
+		smp_mb();	/* make sure atomic access hw */
+
+		status = cmdq_thread_force_remove_task(task);
+		if (thread->task_count > 0)
+			cmdq_thread_resume(thread);
+
+		spin_unlock_irqrestore(&cqctx->exec_lock, flags);
+		wake_up(&cqctx->wait_queue[thread->id]);
+	}
+
+	cmdq_thread_put(cqctx, thread);
+	task->thread = NULL;
+	cmdq_task_release_internal(task);
+	return 0;
+}
+
+struct cmdq_task_error_report {
+	bool throw_err;
+	const char *module;
+	u32 inst_a;
+	u32 inst_b;
+	u32 irq_flag;
+};
+
+static int cmdq_task_handle_error_result(
+		struct cmdq_task *task, int wait_q,
+		struct cmdq_task_error_report *error_report)
+{
+	struct cmdq *cqctx = task->cqctx;
+	struct device *dev = cqctx->dev;
+	struct cmdq_thread *thread = task->thread;
+	int status = 0;
+	int i;
+	bool is_err = false;
+	struct cmdq_task *next_task;
+	struct cmdq_task *prev_task;
+	int cookie;
+	unsigned long thread_pc;
+	u32 *prev_va, *curr_va;
+
+	dev_err(dev,
+		"task(0x%p) state is not TASK_STATE_DONE, but %d.\n",
+		task, task->task_state);
+
+	/*
+	 * Oops, that task is not done.
+	 * We have several possible error cases:
+	 * 1. task still running (hang / timeout)
+	 * 2. IRQ pending (done or error/timeout IRQ)
+	 * 3. task's SW thread has been signaled (e.g. SIGKILL)
+	 */
+
+	/*
+	 * suspend HW thread first,
+	 * so that we work in a consistent state
+	 */
+	status = cmdq_thread_suspend(cqctx, thread);
+	if (status < 0)
+		error_report->throw_err = true;
+
+	/* The cookie of the task currently being processed */
+	cookie = cmdq_thread_get_cookie(thread) + 1;
+	thread_pc = cmdq_thread_readl(thread, CMDQ_THR_CURR_ADDR_OFFSET);
+
+	/* process any pending IRQ */
+	error_report->irq_flag = cmdq_thread_readl(thread,
+			CMDQ_THR_IRQ_STATUS_OFFSET);
+	if (error_report->irq_flag & CMDQ_THR_IRQ_ERROR)
+		cmdq_core_handle_error(cqctx, thread, error_report->irq_flag);
+	else if (error_report->irq_flag & CMDQ_THR_IRQ_DONE)
+		cmdq_core_handle_done(cqctx, thread, error_report->irq_flag);
+
+	cmdq_thread_writel(thread, ~error_report->irq_flag,
+			   CMDQ_THR_IRQ_STATUS_OFFSET);
+
+	/* check if this task has finished after handling pending IRQ */
+	if (task->task_state == TASK_STATE_DONE)
+		return 0;
+
+	/* Then decide we are SW timeout or SIGNALed (not an error) */
+	if (!wait_q) {
+		/* SW timeout and no IRQ received */
+		is_err = true;
+		dev_err(dev, "SW timeout of task 0x%p on thread %d\n",
+			task, thread->id);
+		error_report->throw_err = true;
+		cmdq_core_parse_error(task,
+				      &error_report->module,
+				      &error_report->irq_flag,
+				      &error_report->inst_a,
+				      &error_report->inst_b);
+		status = -ETIMEDOUT;
+	} else if (wait_q < 0) {
+		/*
+		 * Task is killed.
+		 * Not an error, but still need to remove.
+		 */
+		is_err = false;
+
+		if (wait_q == -ERESTARTSYS)
+			dev_err(dev,
+				"Task 0x%p KILLED by wait_q = -ERESTARTSYS\n",
+				task);
+		else if (wait_q == -EINTR)
+			dev_err(dev,
+				"Task 0x%p KILLED by wait_q = -EINTR\n",
+				task);
+		else
+			dev_err(dev,
+				"Task 0x%p KILLED by wait_q = %d\n",
+				task, wait_q);
+
+		status = wait_q;
+	}
+
+	if (task->task_state == TASK_STATE_BUSY) {
+		/*
+		 * if task_state is BUSY,
+		 * this means we did not reach EOC,
+		 * did not have error IRQ.
+		 * - remove the task from thread.cur_task[]
+		 * - and decrease thread.task_count
+		 * NOTE: after this,
+		 * the cur_task will not contain link to task anymore.
+		 * and task should become TASK_STATE_ERROR
+		 */
+
+		/* we find our place in thread->cur_task[]. */
+		for (i = 0; i < CMDQ_MAX_TASK_IN_THREAD; i++) {
+			if (thread->cur_task[i] == task) {
+				/* update task_count and cur_task[] */
+				cmdq_thread_remove_task_by_index(
+						thread, i, is_err ?
+						TASK_STATE_ERROR :
+						TASK_STATE_KILLED);
+				break;
+			}
+		}
+	}
+
+	next_task = NULL;
+
+	/* find task's jump destination or no next task*/
+	curr_va = task->va_base;
+	if (curr_va[task->num_cmd - 1] == CMDQ_JUMP_BY_PA)
+		next_task = cmdq_thread_search_task_by_pc(
+				thread,
+				curr_va[task->num_cmd - 2]);
+
+	/*
+	 * Then, we try remove task from the chain of thread->cur_task.
+	 * . if HW PC falls in task range
+	 * . HW EXEC_CNT += 1
+	 * . thread.wait_cookie += 1
+	 * . set HW PC to next task head
+	 * . if not, find previous task
+	 *                (whose jump address is task->mva_base)
+	 * . check if HW PC points is not at the EOC/JUMP end
+	 * . change jump to fake EOC(no IRQ)
+	 * . insert jump to next task head and increase cmd buffer size
+	 * . if there is no next task, set HW End Address
+	 */
+	if (task->num_cmd && thread_pc >= task->mva_base &&
+	    thread_pc <= (task->mva_base + task->command_size)) {
+		if (next_task) {
+			/* cookie already +1 */
+			cmdq_thread_writel(thread, cookie,
+					   CMDQ_THR_EXEC_CNT_OFFSET);
+			thread->wait_cookie = cookie + 1;
+			cmdq_thread_writel(thread, next_task->mva_base,
+					   CMDQ_THR_CURR_ADDR_OFFSET);
+		}
+	} else {
+		prev_task = NULL;
+		for (i = 0; i < CMDQ_MAX_TASK_IN_THREAD; i++) {
+			u32 prev_num, curr_num;
+
+			prev_task = thread->cur_task[i];
+			if (!prev_task)
+				continue;
+
+			prev_va = prev_task->va_base;
+			prev_num = prev_task->num_cmd;
+			if (!prev_num)
+				continue;
+
+			curr_va = task->va_base;
+			curr_num = task->num_cmd;
+
+			/* find which task JUMP into task */
+			if (prev_va[prev_num - 2] == task->mva_base &&
+			    prev_va[prev_num - 1] == CMDQ_JUMP_BY_PA) {
+				/* Copy Jump instruction */
+				prev_va[prev_num - 2] =
+					curr_va[curr_num - 2];
+				prev_va[prev_num - 1] =
+					curr_va[curr_num - 1];
+
+				if (next_task)
+					cmdq_thread_reorder_task_array(
+							thread, i);
+
+				/*
+				 * Give up fetched command,
+				 * invoke CMDQ HW to re-fetch command.
+				 */
+				cmdq_core_invalidate_hw_fetched_buffer(
+						cqctx, thread);
+
+				break;
+			}
+		}
+	}
+
+	return status;
+}
+
+static int cmdq_task_wait_result(struct cmdq_task *task, int wait_q)
+{
+	struct cmdq *cqctx = task->cqctx;
+	struct cmdq_thread *thread = task->thread;
+	int status = 0;
+	unsigned long flags;
+	struct cmdq_task_error_report error_report = { 0 };
+
+	/*
+	 * Note that although we disable IRQ, HW continues to execute
+	 * so it's possible to have pending IRQ
+	 */
+	spin_lock_irqsave(&cqctx->exec_lock, flags);
+
+	if (task->task_state != TASK_STATE_DONE)
+		status = cmdq_task_handle_error_result(
+				task, wait_q, &error_report);
+
+	if (thread->task_count <= 0)
+		cmdq_thread_disable(cqctx, thread);
+	else
+		cmdq_thread_resume(thread);
+
+	spin_unlock_irqrestore(&cqctx->exec_lock, flags);
+
+	if (error_report.throw_err) {
+		u32 op = error_report.inst_a >> CMDQ_OP_CODE_SHIFT;
+
+		switch (op) {
+		case CMDQ_CODE_WFE:
+			dev_err(cqctx->dev,
+				"%s in CMDQ IRQ:0x%02x, INST:(0x%08x, 0x%08x), OP:WAIT EVENT:%s\n",
+				error_report.module, error_report.irq_flag,
+				error_report.inst_a, error_report.inst_b,
+				cmdq_event_get_name(error_report.inst_a &
+						    CMDQ_ARG_A_MASK));
+			break;
+		default:
+			dev_err(cqctx->dev,
+				"%s in CMDQ IRQ:0x%02x, INST:(0x%08x, 0x%08x), OP:%s\n",
+				error_report.module, error_report.irq_flag,
+				error_report.inst_a, error_report.inst_b,
+				cmdq_core_parse_op(op));
+			break;
+		}
+	}
+
+	return status;
+}
+
+static int cmdq_task_wait_done(struct cmdq_task *task)
+{
+	struct cmdq *cqctx = task->cqctx;
+	struct device *dev = cqctx->dev;
+	int wait_q;
+	unsigned long timeout = msecs_to_jiffies(
+			CMDQ_ACQUIRE_THREAD_TIMEOUT_MS);
+
+	/*
+	 * wait for acquire thread
+	 * (this is done by cmdq_core_consume_waiting_list);
+	 */
+	wait_q = wait_event_timeout(
+			cqctx->thread_dispatch_queue,
+			task->thread, timeout);
+
+	if (!wait_q) {
+		mutex_lock(&cqctx->task_mutex);
+
+		/*
+		 * it's possible that the task was just consumed now.
+		 * so check again.
+		 */
+		if (!task->thread) {
+			/*
+			 * Task may have released,
+			 * or starved to death.
+			 */
+			dev_err(dev,
+				"task(0x%p) timeout with invalid thread\n",
+				task);
+
+			/*
+			 * remove from waiting list,
+			 * so that it won't be consumed in the future
+			 */
+			list_del_init(&task->list_entry);
+
+			mutex_unlock(&cqctx->task_mutex);
+			return -EINVAL;
+		}
+
+		/* valid thread, so we keep going */
+		mutex_unlock(&cqctx->task_mutex);
+	}
+
+	/* start to wait */
+	wait_q = wait_event_timeout(cqctx->wait_queue[task->thread->id],
+				    (task->task_state != TASK_STATE_BUSY &&
+				     task->task_state != TASK_STATE_WAITING),
+				    msecs_to_jiffies(CMDQ_DEFAULT_TIMEOUT_MS));
+	if (!wait_q)
+		dev_dbg(dev, "timeout!\n");
+
+	/* wake up and continue */
+	return cmdq_task_wait_result(task, wait_q);
+}
+
+static int cmdq_task_wait_and_release(struct cmdq_task *task)
+{
+	struct cmdq *cqctx;
+	int status;
+	struct cmdq_thread *thread;
+
+	if (!task) {
+		pr_err("%s err ptr=0x%p\n", __func__, task);
+		return -EFAULT;
+	}
+
+	if (task->task_state == TASK_STATE_IDLE) {
+		pr_err("%s task=0x%p is IDLE\n", __func__, task);
+		return -EFAULT;
+	}
+
+	cqctx = task->cqctx;
+	thread = task->thread;
+
+	/* wait for task finish */
+	status = cmdq_task_wait_done(task);
+
+	/* release */
+	cmdq_thread_put(cqctx, thread);
+	task->thread = NULL;
+	cmdq_task_release_internal(task);
+
+	return status;
+}
+
+static void cmdq_core_auto_release_work(struct work_struct *work_item)
+{
+	struct cmdq_task *task;
+	int status;
+	struct cmdq_task_cb cb;
+
+	task = container_of(work_item, struct cmdq_task, auto_release_work);
+	cb = task->cb;
+	status = cmdq_task_wait_and_release(task);
+
+	/* isr fail, so call isr_cb here to prevent lock */
+	if (status && cb.isr_cb)
+		cb.isr_cb(cb.isr_data);
+
+	if (cb.done_cb)
+		cb.done_cb(cb.done_data);
+}
+
+static int cmdq_core_auto_release_task(struct cmdq_task *task)
+{
+	struct cmdq *cqctx = task->cqctx;
+
+	/*
+	 * the work item is embeded in task already
+	 * but we need to initialized it
+	 */
+	INIT_WORK(&task->auto_release_work, cmdq_core_auto_release_work);
+	queue_work(cqctx->task_auto_release_wq, &task->auto_release_work);
+	return 0;
+}
+
+static int cmdq_core_submit_task(struct cmdq_command *cmd_desc)
+{
+	struct device *dev = cmd_desc->cqctx->dev;
+	int status;
+	struct cmdq_task *task;
+
+	status = cmdq_core_submit_task_async(cmd_desc, &task, NULL);
+	if (status < 0) {
+		dev_err(dev, "cmdq_core_submit_task_async failed=%d\n", status);
+		return status;
+	}
+
+	status = cmdq_task_wait_and_release(task);
+	if (status < 0)
+		dev_err(dev, "task(0x%p) wait fail\n", task);
+
+	return status;
+}
+
+static void cmdq_core_deinitialize(struct platform_device *pdev)
+{
+	struct cmdq *cqctx = platform_get_drvdata(pdev);
+	struct list_head *p;
+	int i;
+	struct list_head *lists[] = {
+		&cqctx->task_free_list,
+		&cqctx->task_active_list,
+		&cqctx->task_wait_list
+	};
+
+	/*
+	 * Directly destroy the auto release WQ
+	 * since we're going to release tasks anyway.
+	 */
+	destroy_workqueue(cqctx->task_auto_release_wq);
+	cqctx->task_auto_release_wq = NULL;
+
+	destroy_workqueue(cqctx->task_consume_wq);
+	cqctx->task_consume_wq = NULL;
+
+	/* release all tasks in both list */
+	for (i = 0; i < ARRAY_SIZE(lists); i++) {
+		list_for_each(p, lists[i]) {
+			struct cmdq_task *task;
+
+			mutex_lock(&cqctx->task_mutex);
+
+			task = list_entry(p, struct cmdq_task, list_entry);
+
+			/* free allocated DMA buffer */
+			cmdq_task_free_command_buffer(task);
+			kmem_cache_free(cqctx->task_cache, task);
+			list_del(p);
+
+			mutex_unlock(&cqctx->task_mutex);
+		}
+	}
+
+	kmem_cache_destroy(cqctx->task_cache);
+	cqctx->task_cache = NULL;
+
+	/* release command buffer pool */
+	cmdq_cmd_buf_pool_uninit(cqctx);
+}
+
+static irqreturn_t cmdq_irq_handler(int irq, void *dev)
+{
+	struct cmdq *cqctx = dev;
+	int i;
+	u32 irq_status;
+	bool handled = false;
+
+	irq_status = readl(cqctx->base + CMDQ_CURR_IRQ_STATUS_OFFSET);
+	irq_status &= CMDQ_IRQ_MASK;
+	for (i = 0;
+	     irq_status != CMDQ_IRQ_MASK && i < CMDQ_MAX_THREAD_COUNT;
+	     i++) {
+		/* STATUS bit set to 0 means IRQ asserted */
+		if (irq_status & BIT(i))
+			continue;
+
+		/*
+		 * We mark irq_status to 1 to denote finished
+		 * processing, and we can early-exit if no more
+		 * threads being asserted.
+		 */
+		irq_status |= BIT(i);
+
+		cmdq_core_handle_irq(cqctx, i);
+		handled = true;
+	}
+
+	if (!handled)
+		return IRQ_NONE;
+
+	queue_work(cqctx->task_consume_wq,
+		   &cqctx->task_consume_wait_queue_item);
+	return IRQ_HANDLED;
+}
+
+static int cmdq_core_initialize(struct platform_device *pdev,
+				struct cmdq **cqctx)
+{
+	struct cmdq *lcqctx; /* local cmdq context */
+	int i;
+	int ret = 0;
+
+	lcqctx = devm_kzalloc(&pdev->dev, sizeof(*lcqctx), GFP_KERNEL);
+
+	/* save dev */
+	lcqctx->dev = &pdev->dev;
+
+	/* initial cmdq device related data */
+	ret = cmdq_dev_init(pdev, lcqctx);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to init cmdq device\n");
+		goto fail_dev;
+	}
+
+	/* initial mutex, spinlock */
+	mutex_init(&lcqctx->task_mutex);
+	spin_lock_init(&lcqctx->thread_lock);
+	spin_lock_init(&lcqctx->exec_lock);
+
+	/* initial wait queue for notification */
+	for (i = 0; i < ARRAY_SIZE(lcqctx->wait_queue); i++)
+		init_waitqueue_head(&lcqctx->wait_queue[i]);
+	init_waitqueue_head(&lcqctx->thread_dispatch_queue);
+
+	/* create task pool */
+	lcqctx->task_cache = kmem_cache_create(
+			CMDQ_DRIVER_DEVICE_NAME "_task",
+			sizeof(struct cmdq_task),
+			__alignof__(struct cmdq_task),
+			SLAB_POISON | SLAB_HWCACHE_ALIGN | SLAB_RED_ZONE,
+			&cmdq_task_ctor);
+
+	/* initialize task lists */
+	INIT_LIST_HEAD(&lcqctx->task_free_list);
+	INIT_LIST_HEAD(&lcqctx->task_active_list);
+	INIT_LIST_HEAD(&lcqctx->task_wait_list);
+	INIT_WORK(&lcqctx->task_consume_wait_queue_item,
+		  cmdq_core_consume_waiting_list);
+
+	/* initialize command buffer pool */
+	ret = cmdq_cmd_buf_pool_init(lcqctx);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to init command buffer pool\n");
+		goto fail_cmd_buf_pool;
+	}
+
+	lcqctx->task_auto_release_wq = alloc_ordered_workqueue(
+			"%s", WQ_MEM_RECLAIM | WQ_HIGHPRI, "cmdq_auto_release");
+	lcqctx->task_consume_wq = alloc_ordered_workqueue(
+			"%s", WQ_MEM_RECLAIM | WQ_HIGHPRI, "cmdq_task");
+
+	/* initialize cmdq thread */
+	for (i = 0; i < CMDQ_MAX_THREAD_COUNT ; i++) {
+		lcqctx->thread[i].id = i;
+		lcqctx->thread[i].base = lcqctx->base + CMDQ_THR_BASE +
+					 CMDQ_THR_SHIFT * i;
+	}
+
+	*cqctx = lcqctx;
+	return ret;
+
+fail_cmd_buf_pool:
+	destroy_workqueue(lcqctx->task_auto_release_wq);
+	destroy_workqueue(lcqctx->task_consume_wq);
+	kmem_cache_destroy(lcqctx->task_cache);
+
+fail_dev:
+	return ret;
+}
+
+static int cmdq_rec_realloc_cmd_buffer(struct cmdq_rec *handle, size_t size)
+{
+	void *new_buf;
+
+	new_buf = krealloc(handle->buf, size, GFP_KERNEL | __GFP_ZERO);
+	if (!new_buf)
+		return -ENOMEM;
+	handle->buf = new_buf;
+	handle->buf_size = size;
+	return 0;
+}
+
+static int cmdq_rec_stop_running_task(struct cmdq_rec *handle)
+{
+	int status;
+
+	status = cmdq_core_release_task(handle->running_task);
+	handle->running_task = NULL;
+	return status;
+}
+
+int cmdq_rec_create(struct device *dev, u64 engine_flag,
+		    struct cmdq_rec **handle_ptr)
+{
+	struct cmdq_rec *handle;
+	int ret;
+
+	handle = kzalloc(sizeof(*handle), GFP_KERNEL);
+	if (!handle)
+		return -ENOMEM;
+
+	handle->cqctx = dev_get_drvdata(dev);
+	handle->engine_flag = engine_flag;
+
+	ret = cmdq_rec_realloc_cmd_buffer(handle, CMDQ_INITIAL_CMD_BLOCK_SIZE);
+	if (ret) {
+		kfree(handle);
+		return ret;
+	}
+
+	*handle_ptr = handle;
+
+	return 0;
+}
+EXPORT_SYMBOL(cmdq_rec_create);
+
+static int cmdq_rec_append_command(struct cmdq_rec *handle,
+				   enum cmdq_code code,
+				   u32 arg_a, u32 arg_b)
+{
+	struct cmdq *cqctx;
+	struct device *dev;
+	int subsys;
+	u32 *cmd_ptr;
+	int ret;
+
+	cqctx = handle->cqctx;
+	dev = cqctx->dev;
+	cmd_ptr = (u32 *)(handle->buf + handle->command_size);
+
+	if (handle->finalized) {
+		dev_err(dev,
+			"already finalized record(cannot add more command)");
+		dev_err(dev, "handle=0x%p, pid=%d\n", handle, current->pid);
+		return -EBUSY;
+	}
+
+	/* check if we have sufficient buffer size */
+	if (unlikely(handle->command_size + CMDQ_INST_SIZE > handle->buf_size)) {
+		ret = cmdq_rec_realloc_cmd_buffer(handle, handle->buf_size * 2);
+		if (ret)
+			return ret;
+	}
+
+	/*
+	 * we must re-calculate current PC
+	 * because we may already insert MARKER inst.
+	 */
+	cmd_ptr = (u32 *)(handle->buf + handle->command_size);
+
+	switch (code) {
+	case CMDQ_CODE_MOVE:
+		cmd_ptr[0] = arg_b;
+		cmd_ptr[1] = (CMDQ_CODE_MOVE << CMDQ_OP_CODE_SHIFT) |
+			     (arg_a & CMDQ_ARG_A_MASK);
+		break;
+	case CMDQ_CODE_WRITE:
+		subsys = cmdq_subsys_from_phys_addr(cqctx, arg_a);
+		if (subsys < 0) {
+			dev_err(dev,
+				"unsupported memory base address 0x%08x\n",
+				arg_a);
+			return -EFAULT;
+		}
+
+		cmd_ptr[0] = arg_b;
+		cmd_ptr[1] = (CMDQ_CODE_WRITE << CMDQ_OP_CODE_SHIFT) |
+			     (arg_a & CMDQ_ARG_A_WRITE_MASK) |
+			     ((subsys & CMDQ_SUBSYS_MASK) << CMDQ_SUBSYS_SHIFT);
+		break;
+	case CMDQ_CODE_JUMP:
+		cmd_ptr[0] = arg_b;
+		cmd_ptr[1] = (CMDQ_CODE_JUMP << CMDQ_OP_CODE_SHIFT) |
+			     (arg_a & CMDQ_ARG_A_MASK);
+		break;
+	case CMDQ_CODE_WFE:
+		/*
+		 * bit 0-11: wait_value, 1
+		 * bit 15: to_wait, true
+		 * bit 16-27: update_value, 0
+		 * bit 31: to_update, true
+		 */
+		cmd_ptr[0] = CMDQ_WFE_UPDATE | CMDQ_WFE_WAIT |
+			     CMDQ_WFE_WAIT_VALUE;
+		cmd_ptr[1] = (CMDQ_CODE_WFE << CMDQ_OP_CODE_SHIFT) | arg_a;
+		break;
+	case CMDQ_CODE_CLEAR_EVENT:
+		/*
+		 * bit 0-11: wait_value, 0
+		 * bit 15: to_wait, false
+		 * bit 16-27: update_value, 0
+		 * bit 31: to_update, true
+		 */
+		cmd_ptr[0] = CMDQ_WFE_UPDATE;
+		cmd_ptr[1] = (CMDQ_CODE_WFE << CMDQ_OP_CODE_SHIFT) | arg_a;
+		break;
+	case CMDQ_CODE_EOC:
+		cmd_ptr[0] = arg_b;
+		cmd_ptr[1] = (CMDQ_CODE_EOC << CMDQ_OP_CODE_SHIFT) |
+			     (arg_a & CMDQ_ARG_A_MASK);
+		break;
+	default:
+		return -EFAULT;
+	}
+
+	handle->command_size += CMDQ_INST_SIZE;
+
+	return 0;
+}
+
+int cmdq_rec_reset(struct cmdq_rec *handle)
+{
+	if (handle->running_task)
+		cmdq_rec_stop_running_task(handle);
+
+	handle->command_size = 0;
+	handle->finalized = false;
+
+	return 0;
+}
+EXPORT_SYMBOL(cmdq_rec_reset);
+
+int cmdq_rec_write(struct cmdq_rec *handle, u32 value, u32 addr)
+{
+	return cmdq_rec_append_command(handle, CMDQ_CODE_WRITE, addr, value);
+}
+EXPORT_SYMBOL(cmdq_rec_write);
+
+int cmdq_rec_write_mask(struct cmdq_rec *handle, u32 value,
+			u32 addr, u32 mask)
+{
+	int ret;
+
+	if (mask != 0xffffffff) {
+		ret = cmdq_rec_append_command(handle, CMDQ_CODE_MOVE, 0, ~mask);
+		if (ret)
+			return ret;
+
+		addr = addr | CMDQ_ENABLE_MASK;
+	}
+
+	return cmdq_rec_append_command(handle, CMDQ_CODE_WRITE, addr, value);
+}
+EXPORT_SYMBOL(cmdq_rec_write_mask);
+
+int cmdq_rec_wait(struct cmdq_rec *handle, enum cmdq_event event)
+{
+	if (event == CMDQ_SYNC_TOKEN_INVALID || event >= CMDQ_SYNC_TOKEN_MAX ||
+	    event < 0)
+		return -EINVAL;
+
+	return cmdq_rec_append_command(handle, CMDQ_CODE_WFE, event, 0);
+}
+EXPORT_SYMBOL(cmdq_rec_wait);
+
+int cmdq_rec_clear_event(struct cmdq_rec *handle, enum cmdq_event event)
+{
+	if (event == CMDQ_SYNC_TOKEN_INVALID || event >= CMDQ_SYNC_TOKEN_MAX ||
+	    event < 0)
+		return -EINVAL;
+
+	return cmdq_rec_append_command(handle, CMDQ_CODE_CLEAR_EVENT, event, 0);
+}
+EXPORT_SYMBOL(cmdq_rec_clear_event);
+
+static int cmdq_rec_finalize_command(struct cmdq_rec *handle)
+{
+	int status;
+
+	if (handle->finalized)
+		return 0;
+
+	/* insert EOC and generate IRQ for each command iteration */
+	status = cmdq_rec_append_command(handle, CMDQ_CODE_EOC,
+					 0, CMDQ_EOC_IRQ_EN);
+	if (status)
+		return status;
+
+	status = cmdq_rec_append_command(handle, CMDQ_CODE_JUMP, 0,
+			CMDQ_INST_SIZE); /* JUMP to begin */
+	if (status)
+		return status;
+
+	handle->finalized = true;
+
+	return 0;
+}
+
+static int cmdq_rec_fill_cmd_desc(struct cmdq_rec *handle,
+				  struct cmdq_command *desc)
+{
+	int ret;
+
+	ret = cmdq_rec_finalize_command(handle);
+	if (ret)
+		return ret;
+
+	desc->cqctx = handle->cqctx;
+	desc->engine_flag = handle->engine_flag;
+	desc->base = handle->buf;
+	desc->size = handle->command_size;
+
+	return ret;
+}
+
+int cmdq_rec_flush(struct cmdq_rec *handle)
+{
+	int ret;
+	struct cmdq_command desc;
+
+	ret = cmdq_rec_fill_cmd_desc(handle, &desc);
+	if (ret)
+		return ret;
+
+	return cmdq_core_submit_task(&desc);
+}
+EXPORT_SYMBOL(cmdq_rec_flush);
+
+static int cmdq_rec_flush_async_cb(struct cmdq_rec *handle,
+				   cmdq_async_flush_cb isr_cb,
+				   void *isr_data,
+				   cmdq_async_flush_cb done_cb,
+				   void *done_data)
+{
+	int ret;
+	struct cmdq_command desc;
+	struct cmdq_task *task;
+	struct cmdq_task_cb cb;
+
+	ret = cmdq_rec_fill_cmd_desc(handle, &desc);
+	if (ret)
+		return ret;
+
+	cb.isr_cb = isr_cb;
+	cb.isr_data = isr_data;
+	cb.done_cb = done_cb;
+	cb.done_data = done_data;
+
+	ret = cmdq_core_submit_task_async(&desc, &task, &cb);
+	if (ret)
+		return ret;
+
+	ret = cmdq_core_auto_release_task(task);
+
+	return ret;
+}
+
+int cmdq_rec_flush_async(struct cmdq_rec *handle)
+{
+	return cmdq_rec_flush_async_cb(handle, NULL, NULL, NULL, NULL);
+}
+EXPORT_SYMBOL(cmdq_rec_flush_async);
+
+int cmdq_rec_flush_async_callback(struct cmdq_rec *handle,
+				  cmdq_async_flush_cb isr_cb,
+				  void *isr_data,
+				  cmdq_async_flush_cb done_cb,
+				  void *done_data)
+{
+	return cmdq_rec_flush_async_cb(handle, isr_cb, isr_data,
+				       done_cb, done_data);
+}
+EXPORT_SYMBOL(cmdq_rec_flush_async_callback);
+
+void cmdq_rec_destroy(struct cmdq_rec *handle)
+{
+	if (handle->running_task)
+		cmdq_rec_stop_running_task(handle);
+
+	kfree(handle->buf);
+	kfree(handle);
+}
+EXPORT_SYMBOL(cmdq_rec_destroy);
+
+static int cmdq_pm_notifier_cb(struct notifier_block *nb, unsigned long event,
+			       void *ptr)
+{
+	struct cmdq *cqctx = container_of(nb, struct cmdq, pm_notifier);
+
+	switch (event) {
+	case PM_SUSPEND_PREPARE:
+		/*
+		 * Going to suspend the system
+		 * The next stage is freeze process.
+		 * We will queue all request in suspend callback,
+		 * so don't care this stage
+		 */
+		return NOTIFY_DONE;
+	case PM_POST_SUSPEND:
+		/*
+		 * processes had resumed in previous stage
+		 * (system resume callback)
+		 * resume CMDQ driver to execute.
+		 */
+		cmdq_core_resumed_notifier(cqctx);
+		return NOTIFY_OK;
+	default:
+		return NOTIFY_DONE;
+	}
+	return NOTIFY_DONE;
+}
+
+static int cmdq_suspend(struct device *dev)
+{
+	struct cmdq *cqctx;
+	unsigned long flags;
+	u32 exec_threads;
+	int ref_count;
+	struct cmdq_task *task;
+	struct list_head *p;
+	int i;
+
+	cqctx = dev_get_drvdata(dev);
+	exec_threads = readl(cqctx->base + CMDQ_CURR_LOADED_THR_OFFSET);
+	ref_count = atomic_read(&cqctx->thread_usage);
+
+	if (ref_count > 0 || exec_threads & CMDQ_THR_EXECUTING) {
+		dev_err(dev,
+			"[SUSPEND] other running, kill tasks. threads:0x%08x, ref:%d\n",
+			exec_threads, ref_count);
+
+		/*
+		 * We need to ensure the system is ready to suspend,
+		 * so kill all running CMDQ tasks and release HW engines.
+		 */
+
+		/* remove all active task from thread */
+		dev_err(dev, "[SUSPEND] remove all active tasks\n");
+		list_for_each(p, &cqctx->task_active_list) {
+			task = list_entry(p, struct cmdq_task, list_entry);
+
+			if (!task->thread)
+				continue;
+
+			spin_lock_irqsave(&cqctx->exec_lock, flags);
+			cmdq_thread_force_remove_task(task);
+			task->task_state = TASK_STATE_KILLED;
+			spin_unlock_irqrestore(&cqctx->exec_lock, flags);
+
+			/*
+			 * release all thread and
+			 * mark all active tasks as "KILLED"
+			 * (so that thread won't release again)
+			 */
+			dev_err(dev,
+				"[SUSPEND] release all threads and HW clocks\n");
+			cmdq_thread_put(cqctx, task->thread);
+			task->thread = NULL;
+
+			/* release cmdq_task resources */
+			cmdq_task_release_internal(task);
+		}
+
+		/* disable all HW thread */
+		dev_err(dev, "[SUSPEND] disable all HW threads\n");
+		for (i = 0; i < CMDQ_MAX_THREAD_COUNT; i++)
+			cmdq_thread_disable(cqctx, &cqctx->thread[i]);
+
+		/* reset all cmdq_thread */
+		memset(&cqctx->thread[0], 0, sizeof(cqctx->thread));
+	}
+
+	spin_lock_irqsave(&cqctx->thread_lock, flags);
+	cqctx->suspended = true;
+	spin_unlock_irqrestore(&cqctx->thread_lock, flags);
+
+	/* ALWAYS allow suspend */
+	return 0;
+}
+
+static int cmdq_resume(struct device *dev)
+{
+	return 0;
+}
+
+static int cmdq_probe(struct platform_device *pdev)
+{
+	struct cmdq *cqctx;
+	int ret;
+
+	/* init cmdq context, and save it */
+	ret = cmdq_core_initialize(pdev, &cqctx);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to init cmdq context\n");
+		return ret;
+	}
+	platform_set_drvdata(pdev, cqctx);
+
+	ret = devm_request_irq(&pdev->dev, cqctx->irq, cmdq_irq_handler,
+			       IRQF_TRIGGER_LOW | IRQF_SHARED,
+			       CMDQ_DRIVER_DEVICE_NAME, cqctx);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register ISR (%d)\n", ret);
+		goto fail;
+	}
+
+	cqctx->clock = devm_clk_get(&pdev->dev, CMDQ_CLK_NAME);
+	if (IS_ERR(cqctx->clock)) {
+		dev_err(&pdev->dev, "failed to get clk:%s\n", CMDQ_CLK_NAME);
+		ret = PTR_ERR(cqctx->clock);
+		goto fail;
+	}
+
+	/* hibernation and suspend events */
+	cqctx->pm_notifier.notifier_call = cmdq_pm_notifier_cb;
+	cqctx->pm_notifier.priority = 5;
+	ret = register_pm_notifier(&cqctx->pm_notifier);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register cmdq pm notifier\n");
+		goto fail;
+	}
+
+	cmdq_event_reset(cqctx);
+
+	return ret;
+
+fail:
+	cmdq_core_deinitialize(pdev);
+	return ret;
+}
+
+static int cmdq_remove(struct platform_device *pdev)
+{
+	struct cmdq *cqctx = platform_get_drvdata(pdev);
+	int status;
+
+	status = unregister_pm_notifier(&cqctx->pm_notifier);
+	if (status)
+		dev_err(&pdev->dev, "unregister pm notifier failed\n");
+
+	cmdq_core_deinitialize(pdev);
+	return 0;
+}
+
+static const struct dev_pm_ops cmdq_pm_ops = {
+	.suspend = cmdq_suspend,
+	.resume = cmdq_resume,
+};
+
+static const struct of_device_id cmdq_of_ids[] = {
+	{.compatible = "mediatek,mt8173-gce",},
+	{}
+};
+
+static struct platform_driver cmdq_drv = {
+	.probe = cmdq_probe,
+	.remove = cmdq_remove,
+	.driver = {
+		.name = CMDQ_DRIVER_DEVICE_NAME,
+		.owner = THIS_MODULE,
+		.pm = &cmdq_pm_ops,
+		.of_match_table = cmdq_of_ids,
+	}
+};
+
+builtin_platform_driver(cmdq_drv);
diff --git a/include/soc/mediatek/cmdq.h b/include/soc/mediatek/cmdq.h
new file mode 100644
index 0000000..0e80d07
--- /dev/null
+++ b/include/soc/mediatek/cmdq.h
@@ -0,0 +1,211 @@
+/*
+ * Copyright (c) 2015 MediaTek Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License 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.
+ */
+
+#ifndef __MTK_CMDQ_H__
+#define __MTK_CMDQ_H__
+
+#include <linux/platform_device.h>
+#include <linux/types.h>
+
+enum cmdq_eng {
+	CMDQ_ENG_DISP_AAL,
+	CMDQ_ENG_DISP_COLOR0,
+	CMDQ_ENG_DISP_COLOR1,
+	CMDQ_ENG_DISP_DPI0,
+	CMDQ_ENG_DISP_DSI0,
+	CMDQ_ENG_DISP_DSI1,
+	CMDQ_ENG_DISP_GAMMA,
+	CMDQ_ENG_DISP_OD,
+	CMDQ_ENG_DISP_OVL0,
+	CMDQ_ENG_DISP_OVL1,
+	CMDQ_ENG_DISP_PWM0,
+	CMDQ_ENG_DISP_PWM1,
+	CMDQ_ENG_DISP_RDMA0,
+	CMDQ_ENG_DISP_RDMA1,
+	CMDQ_ENG_DISP_RDMA2,
+	CMDQ_ENG_DISP_UFOE,
+	CMDQ_ENG_DISP_WDMA0,
+	CMDQ_ENG_DISP_WDMA1,
+	CMDQ_ENG_MAX,
+};
+
+/* events for CMDQ and display */
+enum cmdq_event {
+	/* Display start of frame(SOF) events */
+	CMDQ_EVENT_DISP_OVL0_SOF = 11,
+	CMDQ_EVENT_DISP_OVL1_SOF = 12,
+	CMDQ_EVENT_DISP_RDMA0_SOF = 13,
+	CMDQ_EVENT_DISP_RDMA1_SOF = 14,
+	CMDQ_EVENT_DISP_RDMA2_SOF = 15,
+	CMDQ_EVENT_DISP_WDMA0_SOF = 16,
+	CMDQ_EVENT_DISP_WDMA1_SOF = 17,
+	/* Display end of frame(EOF) events */
+	CMDQ_EVENT_DISP_OVL0_EOF = 39,
+	CMDQ_EVENT_DISP_OVL1_EOF = 40,
+	CMDQ_EVENT_DISP_RDMA0_EOF = 41,
+	CMDQ_EVENT_DISP_RDMA1_EOF = 42,
+	CMDQ_EVENT_DISP_RDMA2_EOF = 43,
+	CMDQ_EVENT_DISP_WDMA0_EOF = 44,
+	CMDQ_EVENT_DISP_WDMA1_EOF = 45,
+	/* Mutex end of frame(EOF) events */
+	CMDQ_EVENT_MUTEX0_STREAM_EOF = 53,
+	CMDQ_EVENT_MUTEX1_STREAM_EOF = 54,
+	CMDQ_EVENT_MUTEX2_STREAM_EOF = 55,
+	CMDQ_EVENT_MUTEX3_STREAM_EOF = 56,
+	CMDQ_EVENT_MUTEX4_STREAM_EOF = 57,
+	/* Display underrun events */
+	CMDQ_EVENT_DISP_RDMA0_UNDERRUN = 63,
+	CMDQ_EVENT_DISP_RDMA1_UNDERRUN = 64,
+	CMDQ_EVENT_DISP_RDMA2_UNDERRUN = 65,
+	/* Keep this at the end of HW events */
+	CMDQ_MAX_HW_EVENT_COUNT = 260,
+	/* This is max event and also can be used as mask. */
+	CMDQ_SYNC_TOKEN_MAX = 0x1ff,
+	/* Invalid event */
+	CMDQ_SYNC_TOKEN_INVALID = -1,
+};
+
+/* called after isr done or task done */
+typedef int (*cmdq_async_flush_cb)(void *data);
+
+struct cmdq_task;
+struct cmdq;
+
+struct cmdq_rec {
+	struct cmdq		*cqctx;
+	u64			engine_flag;
+	size_t			command_size;
+	void			*buf;
+	size_t			buf_size;
+	/* running task after flush */
+	struct cmdq_task	*running_task;
+	bool			finalized;
+};
+
+/**
+ * cmdq_rec_create() - create command queue record handle
+ * @dev:		device
+ * @engine_flag:	command queue engine flag
+ * @handle_ptr:		command queue record handle pointer to retrieve cmdq_rec
+ *
+ * Return: 0 for success; else the error code is returned
+ */
+int cmdq_rec_create(struct device *dev, u64 engine_flag,
+		    struct cmdq_rec **handle_ptr);
+
+/**
+ * cmdq_rec_reset() - reset command queue record commands
+ * @handle:	the command queue record handle
+ *
+ * Return: 0 for success; else the error code is returned
+ */
+int cmdq_rec_reset(struct cmdq_rec *handle);
+
+/**
+ * cmdq_rec_write() - append write command to the command queue record
+ * @handle:	the command queue record handle
+ * @value:	the specified target register value
+ * @addr:	the specified target register physical address
+ *
+ * Return: 0 for success; else the error code is returned
+ */
+int cmdq_rec_write(struct cmdq_rec *handle, u32 value, u32 addr);
+
+/**
+ * cmdq_rec_write_mask() - append write command with mask to the command queue
+ *			   record
+ * @handle:	the command queue record handle
+ * @value:	the specified target register value
+ * @addr:	the specified target register physical address
+ * @mask:	the specified target register mask
+ *
+ * Return: 0 for success; else the error code is returned
+ */
+int cmdq_rec_write_mask(struct cmdq_rec *handle, u32 value,
+			u32 addr, u32 mask);
+
+/**
+ * cmdq_rec_wait() - append wait command to the command queue record
+ * @handle:	the command queue record handle
+ * @event:	the desired event type to "wait and CLEAR"
+ *
+ * Return: 0 for success; else the error code is returned
+ */
+int cmdq_rec_wait(struct cmdq_rec *handle, enum cmdq_event event);
+
+/**
+ * cmdq_rec_clear_event() - append clear event command to the command queue
+ *			    record
+ * @handle:	the command queue record handle
+ * @event:	the desired event to be cleared
+ *
+ * Return: 0 for success; else the error code is returned
+ */
+int cmdq_rec_clear_event(struct cmdq_rec *handle, enum cmdq_event event);
+
+/**
+ * cmdq_rec_flush() - trigger CMDQ to execute the recorded commands
+ * @handle:	the command queue record handle
+ *
+ * Return: 0 for success; else the error code is returned
+ *
+ * Trigger CMDQ to execute the recorded commands. Note that this is a
+ * synchronous flush function. When the function returned, the recorded
+ * commands have been done.
+ */
+int cmdq_rec_flush(struct cmdq_rec *handle);
+
+/**
+ * cmdq_rec_flush_async() - trigger CMDQ to asynchronously execute the
+ *			    recorded commands
+ * @handle:	the command queue record handle
+ *
+ * Return: 0 for successfully start execution; else the error code is returned
+ *
+ * Trigger CMDQ to asynchronously execute the recorded commands. Note that this
+ * is an ASYNC function. When the function returned, it may or may not be
+ * finished. There is no way to retrieve the result.
+ */
+int cmdq_rec_flush_async(struct cmdq_rec *handle);
+
+/**
+ * cmdq_rec_flush_async_callback() - trigger CMDQ to asynchronously execute
+ *				     the recorded commands and call back after
+ *				     ISR is finished and this flush is finished
+ * @handle:	the command queue record handle
+ * @isr_cb:	called by ISR in the end of CMDQ ISR
+ * @isr_data:	this data will pass back to isr_cb
+ * @done_cb:	called after flush is done
+ * @done_data:	this data will pass back to done_cb
+ *
+ * Return: 0 for success; else the error code is returned
+ *
+ * Trigger CMDQ to asynchronously execute the recorded commands and call back
+ * after ISR is finished and this flush is finished. Note that this is an ASYNC
+ * function. When the function returned, it may or may not be finished. The ISR
+ * callback function is called in the end of ISR, and  the done callback
+ * function is called after all commands are done.
+ */
+int cmdq_rec_flush_async_callback(struct cmdq_rec *handle,
+				  cmdq_async_flush_cb isr_cb,
+				  void *isr_data,
+				  cmdq_async_flush_cb done_cb,
+				  void *done_data);
+
+/**
+ * cmdq_rec_destroy() - destroy command queue record handle
+ * @handle:	the command queue record handle
+ */
+void cmdq_rec_destroy(struct cmdq_rec *handle);
+
+#endif	/* __MTK_CMDQ_H__ */
-- 
1.7.9.5