linux/drivers/mailbox/mtk-cmdq-mailbox.c

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// SPDX-License-Identifier: GPL-2.0
//
// Copyright (c) 2018 MediaTek Inc.
#include <linux/bitops.h>
#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/module.h>
#include <linux/platform_device.h>
#include <linux/mailbox_controller.h>
#include <linux/mailbox/mtk-cmdq-mailbox.h>
#include <linux/of_device.h>
#define CMDQ_OP_CODE_MASK (0xff << CMDQ_OP_CODE_SHIFT)
#define CMDQ_IRQ_MASK 0xffff
#define CMDQ_NUM_CMD(t) (t->cmd_buf_size / CMDQ_INST_SIZE)
#define CMDQ_CURR_IRQ_STATUS 0x10
#define CMDQ_THR_SLOT_CYCLES 0x30
#define CMDQ_THR_BASE 0x100
#define CMDQ_THR_SIZE 0x80
#define CMDQ_THR_WARM_RESET 0x00
#define CMDQ_THR_ENABLE_TASK 0x04
#define CMDQ_THR_SUSPEND_TASK 0x08
#define CMDQ_THR_CURR_STATUS 0x0c
#define CMDQ_THR_IRQ_STATUS 0x10
#define CMDQ_THR_IRQ_ENABLE 0x14
#define CMDQ_THR_CURR_ADDR 0x20
#define CMDQ_THR_END_ADDR 0x24
#define CMDQ_THR_WAIT_TOKEN 0x30
#define CMDQ_THR_PRIORITY 0x40
#define CMDQ_THR_ACTIVE_SLOT_CYCLES 0x3200
#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_DO_WARM_RESET BIT(0)
#define CMDQ_THR_IRQ_DONE 0x1
#define CMDQ_THR_IRQ_ERROR 0x12
#define CMDQ_THR_IRQ_EN (CMDQ_THR_IRQ_ERROR | CMDQ_THR_IRQ_DONE)
#define CMDQ_THR_IS_WAITING BIT(31)
#define CMDQ_JUMP_BY_OFFSET 0x10000000
#define CMDQ_JUMP_BY_PA 0x10000001
struct cmdq_thread {
struct mbox_chan *chan;
void __iomem *base;
struct list_head task_busy_list;
u32 priority;
bool atomic_exec;
};
struct cmdq_task {
struct cmdq *cmdq;
struct list_head list_entry;
dma_addr_t pa_base;
struct cmdq_thread *thread;
struct cmdq_pkt *pkt; /* the packet sent from mailbox client */
};
struct cmdq {
struct mbox_controller mbox;
void __iomem *base;
u32 irq;
u32 thread_nr;
struct cmdq_thread *thread;
struct clk *clock;
bool suspended;
};
static int cmdq_thread_suspend(struct cmdq *cmdq, struct cmdq_thread *thread)
{
u32 status;
writel(CMDQ_THR_SUSPEND, thread->base + CMDQ_THR_SUSPEND_TASK);
/* If already disabled, treat as suspended successful. */
if (!(readl(thread->base + CMDQ_THR_ENABLE_TASK) & CMDQ_THR_ENABLED))
return 0;
if (readl_poll_timeout_atomic(thread->base + CMDQ_THR_CURR_STATUS,
status, status & CMDQ_THR_STATUS_SUSPENDED, 0, 10)) {
dev_err(cmdq->mbox.dev, "suspend GCE thread 0x%x failed\n",
(u32)(thread->base - cmdq->base));
return -EFAULT;
}
return 0;
}
static void cmdq_thread_resume(struct cmdq_thread *thread)
{
writel(CMDQ_THR_RESUME, thread->base + CMDQ_THR_SUSPEND_TASK);
}
static void cmdq_init(struct cmdq *cmdq)
{
WARN_ON(clk_enable(cmdq->clock) < 0);
writel(CMDQ_THR_ACTIVE_SLOT_CYCLES, cmdq->base + CMDQ_THR_SLOT_CYCLES);
clk_disable(cmdq->clock);
}
static int cmdq_thread_reset(struct cmdq *cmdq, struct cmdq_thread *thread)
{
u32 warm_reset;
writel(CMDQ_THR_DO_WARM_RESET, thread->base + CMDQ_THR_WARM_RESET);
if (readl_poll_timeout_atomic(thread->base + CMDQ_THR_WARM_RESET,
warm_reset, !(warm_reset & CMDQ_THR_DO_WARM_RESET),
0, 10)) {
dev_err(cmdq->mbox.dev, "reset GCE thread 0x%x failed\n",
(u32)(thread->base - cmdq->base));
return -EFAULT;
}
return 0;
}
static void cmdq_thread_disable(struct cmdq *cmdq, struct cmdq_thread *thread)
{
cmdq_thread_reset(cmdq, thread);
writel(CMDQ_THR_DISABLED, thread->base + CMDQ_THR_ENABLE_TASK);
}
/* notify GCE to re-fetch commands by setting GCE thread PC */
static void cmdq_thread_invalidate_fetched_data(struct cmdq_thread *thread)
{
writel(readl(thread->base + CMDQ_THR_CURR_ADDR),
thread->base + CMDQ_THR_CURR_ADDR);
}
static void cmdq_task_insert_into_thread(struct cmdq_task *task)
{
struct device *dev = task->cmdq->mbox.dev;
struct cmdq_thread *thread = task->thread;
struct cmdq_task *prev_task = list_last_entry(
&thread->task_busy_list, typeof(*task), list_entry);
u64 *prev_task_base = prev_task->pkt->va_base;
/* let previous task jump to this task */
dma_sync_single_for_cpu(dev, prev_task->pa_base,
prev_task->pkt->cmd_buf_size, DMA_TO_DEVICE);
prev_task_base[CMDQ_NUM_CMD(prev_task->pkt) - 1] =
(u64)CMDQ_JUMP_BY_PA << 32 | task->pa_base;
dma_sync_single_for_device(dev, prev_task->pa_base,
prev_task->pkt->cmd_buf_size, DMA_TO_DEVICE);
cmdq_thread_invalidate_fetched_data(thread);
}
static bool cmdq_command_is_wfe(u64 cmd)
{
u64 wfe_option = CMDQ_WFE_UPDATE | CMDQ_WFE_WAIT | CMDQ_WFE_WAIT_VALUE;
u64 wfe_op = (u64)(CMDQ_CODE_WFE << CMDQ_OP_CODE_SHIFT) << 32;
u64 wfe_mask = (u64)CMDQ_OP_CODE_MASK << 32 | 0xffffffff;
return ((cmd & wfe_mask) == (wfe_op | wfe_option));
}
/* we assume tasks in the same display GCE thread are waiting the same event. */
static void cmdq_task_remove_wfe(struct cmdq_task *task)
{
struct device *dev = task->cmdq->mbox.dev;
u64 *base = task->pkt->va_base;
int i;
dma_sync_single_for_cpu(dev, task->pa_base, task->pkt->cmd_buf_size,
DMA_TO_DEVICE);
for (i = 0; i < CMDQ_NUM_CMD(task->pkt); i++)
if (cmdq_command_is_wfe(base[i]))
base[i] = (u64)CMDQ_JUMP_BY_OFFSET << 32 |
CMDQ_JUMP_PASS;
dma_sync_single_for_device(dev, task->pa_base, task->pkt->cmd_buf_size,
DMA_TO_DEVICE);
}
static bool cmdq_thread_is_in_wfe(struct cmdq_thread *thread)
{
return readl(thread->base + CMDQ_THR_WAIT_TOKEN) & CMDQ_THR_IS_WAITING;
}
static void cmdq_thread_wait_end(struct cmdq_thread *thread,
unsigned long end_pa)
{
struct device *dev = thread->chan->mbox->dev;
unsigned long curr_pa;
if (readl_poll_timeout_atomic(thread->base + CMDQ_THR_CURR_ADDR,
curr_pa, curr_pa == end_pa, 1, 20))
dev_err(dev, "GCE thread cannot run to end.\n");
}
static void cmdq_task_exec_done(struct cmdq_task *task, enum cmdq_cb_status sta)
{
struct cmdq_task_cb *cb = &task->pkt->async_cb;
struct cmdq_cb_data data;
WARN_ON(cb->cb == (cmdq_async_flush_cb)NULL);
data.sta = sta;
data.data = cb->data;
cb->cb(data);
list_del(&task->list_entry);
}
static void cmdq_task_handle_error(struct cmdq_task *task)
{
struct cmdq_thread *thread = task->thread;
struct cmdq_task *next_task;
dev_err(task->cmdq->mbox.dev, "task 0x%p error\n", task);
WARN_ON(cmdq_thread_suspend(task->cmdq, thread) < 0);
next_task = list_first_entry_or_null(&thread->task_busy_list,
struct cmdq_task, list_entry);
if (next_task)
writel(next_task->pa_base, thread->base + CMDQ_THR_CURR_ADDR);
cmdq_thread_resume(thread);
}
static void cmdq_thread_irq_handler(struct cmdq *cmdq,
struct cmdq_thread *thread)
{
struct cmdq_task *task, *tmp, *curr_task = NULL;
u32 curr_pa, irq_flag, task_end_pa;
bool err;
irq_flag = readl(thread->base + CMDQ_THR_IRQ_STATUS);
writel(~irq_flag, thread->base + CMDQ_THR_IRQ_STATUS);
/*
* When ISR call this function, another CPU core could run
* "release task" right before we acquire the spin lock, and thus
* reset / disable this GCE thread, so we need to check the enable
* bit of this GCE thread.
*/
if (!(readl(thread->base + CMDQ_THR_ENABLE_TASK) & CMDQ_THR_ENABLED))
return;
if (irq_flag & CMDQ_THR_IRQ_ERROR)
err = true;
else if (irq_flag & CMDQ_THR_IRQ_DONE)
err = false;
else
return;
curr_pa = readl(thread->base + CMDQ_THR_CURR_ADDR);
list_for_each_entry_safe(task, tmp, &thread->task_busy_list,
list_entry) {
task_end_pa = task->pa_base + task->pkt->cmd_buf_size;
if (curr_pa >= task->pa_base && curr_pa < task_end_pa)
curr_task = task;
if (!curr_task || curr_pa == task_end_pa - CMDQ_INST_SIZE) {
cmdq_task_exec_done(task, CMDQ_CB_NORMAL);
kfree(task);
} else if (err) {
cmdq_task_exec_done(task, CMDQ_CB_ERROR);
cmdq_task_handle_error(curr_task);
kfree(task);
}
if (curr_task)
break;
}
if (list_empty(&thread->task_busy_list)) {
cmdq_thread_disable(cmdq, thread);
clk_disable(cmdq->clock);
}
}
static irqreturn_t cmdq_irq_handler(int irq, void *dev)
{
struct cmdq *cmdq = dev;
unsigned long irq_status, flags = 0L;
int bit;
irq_status = readl(cmdq->base + CMDQ_CURR_IRQ_STATUS) & CMDQ_IRQ_MASK;
if (!(irq_status ^ CMDQ_IRQ_MASK))
return IRQ_NONE;
for_each_clear_bit(bit, &irq_status, fls(CMDQ_IRQ_MASK)) {
struct cmdq_thread *thread = &cmdq->thread[bit];
spin_lock_irqsave(&thread->chan->lock, flags);
cmdq_thread_irq_handler(cmdq, thread);
spin_unlock_irqrestore(&thread->chan->lock, flags);
}
return IRQ_HANDLED;
}
static int cmdq_suspend(struct device *dev)
{
struct cmdq *cmdq = dev_get_drvdata(dev);
struct cmdq_thread *thread;
int i;
bool task_running = false;
cmdq->suspended = true;
for (i = 0; i < cmdq->thread_nr; i++) {
thread = &cmdq->thread[i];
if (!list_empty(&thread->task_busy_list)) {
task_running = true;
break;
}
}
if (task_running)
dev_warn(dev, "exist running task(s) in suspend\n");
clk_unprepare(cmdq->clock);
return 0;
}
static int cmdq_resume(struct device *dev)
{
struct cmdq *cmdq = dev_get_drvdata(dev);
WARN_ON(clk_prepare(cmdq->clock) < 0);
cmdq->suspended = false;
return 0;
}
static int cmdq_remove(struct platform_device *pdev)
{
struct cmdq *cmdq = platform_get_drvdata(pdev);
clk_unprepare(cmdq->clock);
return 0;
}
static int cmdq_mbox_send_data(struct mbox_chan *chan, void *data)
{
struct cmdq_pkt *pkt = (struct cmdq_pkt *)data;
struct cmdq_thread *thread = (struct cmdq_thread *)chan->con_priv;
struct cmdq *cmdq = dev_get_drvdata(chan->mbox->dev);
struct cmdq_task *task;
unsigned long curr_pa, end_pa;
/* Client should not flush new tasks if suspended. */
WARN_ON(cmdq->suspended);
task = kzalloc(sizeof(*task), GFP_ATOMIC);
if (!task)
return -ENOMEM;
task->cmdq = cmdq;
INIT_LIST_HEAD(&task->list_entry);
task->pa_base = pkt->pa_base;
task->thread = thread;
task->pkt = pkt;
if (list_empty(&thread->task_busy_list)) {
WARN_ON(clk_enable(cmdq->clock) < 0);
WARN_ON(cmdq_thread_reset(cmdq, thread) < 0);
writel(task->pa_base, thread->base + CMDQ_THR_CURR_ADDR);
writel(task->pa_base + pkt->cmd_buf_size,
thread->base + CMDQ_THR_END_ADDR);
writel(thread->priority, thread->base + CMDQ_THR_PRIORITY);
writel(CMDQ_THR_IRQ_EN, thread->base + CMDQ_THR_IRQ_ENABLE);
writel(CMDQ_THR_ENABLED, thread->base + CMDQ_THR_ENABLE_TASK);
} else {
WARN_ON(cmdq_thread_suspend(cmdq, thread) < 0);
curr_pa = readl(thread->base + CMDQ_THR_CURR_ADDR);
end_pa = readl(thread->base + CMDQ_THR_END_ADDR);
/*
* Atomic execution should remove the following wfe, i.e. only
* wait event at first task, and prevent to pause when running.
*/
if (thread->atomic_exec) {
/* GCE is executing if command is not WFE */
if (!cmdq_thread_is_in_wfe(thread)) {
cmdq_thread_resume(thread);
cmdq_thread_wait_end(thread, end_pa);
WARN_ON(cmdq_thread_suspend(cmdq, thread) < 0);
/* set to this task directly */
writel(task->pa_base,
thread->base + CMDQ_THR_CURR_ADDR);
} else {
cmdq_task_insert_into_thread(task);
cmdq_task_remove_wfe(task);
smp_mb(); /* modify jump before enable thread */
}
} else {
/* check boundary */
if (curr_pa == end_pa - CMDQ_INST_SIZE ||
curr_pa == end_pa) {
/* set to this task directly */
writel(task->pa_base,
thread->base + CMDQ_THR_CURR_ADDR);
} else {
cmdq_task_insert_into_thread(task);
smp_mb(); /* modify jump before enable thread */
}
}
writel(task->pa_base + pkt->cmd_buf_size,
thread->base + CMDQ_THR_END_ADDR);
cmdq_thread_resume(thread);
}
list_move_tail(&task->list_entry, &thread->task_busy_list);
return 0;
}
static int cmdq_mbox_startup(struct mbox_chan *chan)
{
return 0;
}
static void cmdq_mbox_shutdown(struct mbox_chan *chan)
{
}
static const struct mbox_chan_ops cmdq_mbox_chan_ops = {
.send_data = cmdq_mbox_send_data,
.startup = cmdq_mbox_startup,
.shutdown = cmdq_mbox_shutdown,
};
static struct mbox_chan *cmdq_xlate(struct mbox_controller *mbox,
const struct of_phandle_args *sp)
{
int ind = sp->args[0];
struct cmdq_thread *thread;
if (ind >= mbox->num_chans)
return ERR_PTR(-EINVAL);
thread = (struct cmdq_thread *)mbox->chans[ind].con_priv;
thread->priority = sp->args[1];
thread->atomic_exec = (sp->args[2] != 0);
thread->chan = &mbox->chans[ind];
return &mbox->chans[ind];
}
static int cmdq_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct resource *res;
struct cmdq *cmdq;
int err, i;
cmdq = devm_kzalloc(dev, sizeof(*cmdq), GFP_KERNEL);
if (!cmdq)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
cmdq->base = devm_ioremap_resource(dev, res);
if (IS_ERR(cmdq->base)) {
dev_err(dev, "failed to ioremap gce\n");
return PTR_ERR(cmdq->base);
}
cmdq->irq = platform_get_irq(pdev, 0);
if (!cmdq->irq) {
dev_err(dev, "failed to get irq\n");
return -EINVAL;
}
err = devm_request_irq(dev, cmdq->irq, cmdq_irq_handler, IRQF_SHARED,
"mtk_cmdq", cmdq);
if (err < 0) {
dev_err(dev, "failed to register ISR (%d)\n", err);
return err;
}
dev_dbg(dev, "cmdq device: addr:0x%p, va:0x%p, irq:%d\n",
dev, cmdq->base, cmdq->irq);
cmdq->clock = devm_clk_get(dev, "gce");
if (IS_ERR(cmdq->clock)) {
dev_err(dev, "failed to get gce clk\n");
return PTR_ERR(cmdq->clock);
}
cmdq->thread_nr = (u32)(unsigned long)of_device_get_match_data(dev);
cmdq->mbox.dev = dev;
cmdq->mbox.chans = devm_kcalloc(dev, cmdq->thread_nr,
sizeof(*cmdq->mbox.chans), GFP_KERNEL);
if (!cmdq->mbox.chans)
return -ENOMEM;
cmdq->mbox.num_chans = cmdq->thread_nr;
cmdq->mbox.ops = &cmdq_mbox_chan_ops;
cmdq->mbox.of_xlate = cmdq_xlate;
/* make use of TXDONE_BY_ACK */
cmdq->mbox.txdone_irq = false;
cmdq->mbox.txdone_poll = false;
cmdq->thread = devm_kcalloc(dev, cmdq->thread_nr,
sizeof(*cmdq->thread), GFP_KERNEL);
if (!cmdq->thread)
return -ENOMEM;
for (i = 0; i < cmdq->thread_nr; i++) {
cmdq->thread[i].base = cmdq->base + CMDQ_THR_BASE +
CMDQ_THR_SIZE * i;
INIT_LIST_HEAD(&cmdq->thread[i].task_busy_list);
cmdq->mbox.chans[i].con_priv = (void *)&cmdq->thread[i];
}
err = devm_mbox_controller_register(dev, &cmdq->mbox);
if (err < 0) {
dev_err(dev, "failed to register mailbox: %d\n", err);
return err;
}
platform_set_drvdata(pdev, cmdq);
WARN_ON(clk_prepare(cmdq->clock) < 0);
cmdq_init(cmdq);
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", .data = (void *)16},
{}
};
static struct platform_driver cmdq_drv = {
.probe = cmdq_probe,
.remove = cmdq_remove,
.driver = {
.name = "mtk_cmdq",
.pm = &cmdq_pm_ops,
.of_match_table = cmdq_of_ids,
}
};
static int __init cmdq_drv_init(void)
{
return platform_driver_register(&cmdq_drv);
}
static void __exit cmdq_drv_exit(void)
{
platform_driver_unregister(&cmdq_drv);
}
subsys_initcall(cmdq_drv_init);
module_exit(cmdq_drv_exit);
MODULE_LICENSE("GPL v2");