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linux/drivers/net/wwan/t7xx/t7xx_state_monitor.c
Jinjian Song d785ed945d net: wwan: t7xx: PCIe reset rescan 
WWAN device is programmed to boot in normal mode or fastboot mode,
when triggering a device reset through ACPI call or fastboot switch
command. Maintain state machine synchronization and reprobe logic
after a device reset.

The PCIe device reset triggered by several ways.
E.g.:
 - fastboot: echo "fastboot_switching" > /sys/bus/pci/devices/${bdf}/t7xx_mode.
 - reset: echo "reset" > /sys/bus/pci/devices/${bdf}/t7xx_mode.
 - IRQ: PCIe device request driver to reset itself by an interrupt request.

Use pci_reset_function() as a generic way to reset device, save and
restore the PCIe configuration before and after reset device to ensure
the reprobe process.

Suggestion from Bjorn:
Link: https://lore.kernel.org/all/20230127133034.GA1364550@bhelgaas/

Signed-off-by: Jinjian Song <jinjian.song@fibocom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-08-21 12:57:24 +01:00

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2021, MediaTek Inc.
* Copyright (c) 2021-2022, Intel Corporation.
*
* Authors:
* Haijun Liu <haijun.liu@mediatek.com>
* Eliot Lee <eliot.lee@intel.com>
* Moises Veleta <moises.veleta@intel.com>
* Ricardo Martinez <ricardo.martinez@linux.intel.com>
*
* Contributors:
* Amir Hanania <amir.hanania@intel.com>
* Sreehari Kancharla <sreehari.kancharla@intel.com>
*/
#include <linux/bits.h>
#include <linux/bitfield.h>
#include <linux/completion.h>
#include <linux/device.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/gfp.h>
#include <linux/iopoll.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/kthread.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/wait.h>
#include "t7xx_hif_cldma.h"
#include "t7xx_mhccif.h"
#include "t7xx_modem_ops.h"
#include "t7xx_pci.h"
#include "t7xx_pcie_mac.h"
#include "t7xx_port_proxy.h"
#include "t7xx_reg.h"
#include "t7xx_state_monitor.h"
#define FSM_DRM_DISABLE_DELAY_MS 200
#define FSM_EVENT_POLL_INTERVAL_MS 20
#define FSM_MD_EX_REC_OK_TIMEOUT_MS 10000
#define FSM_MD_EX_PASS_TIMEOUT_MS 45000
#define FSM_CMD_TIMEOUT_MS 2000
#define wait_for_expected_dev_stage(status) \
read_poll_timeout(ioread32, status, \
((status & MISC_STAGE_MASK) == T7XX_DEV_STAGE_LINUX) || \
((status & MISC_STAGE_MASK) == T7XX_DEV_STAGE_LK), 100000, \
20000000, false, IREG_BASE(md->t7xx_dev) + \
T7XX_PCIE_MISC_DEV_STATUS)
void t7xx_fsm_notifier_register(struct t7xx_modem *md, struct t7xx_fsm_notifier *notifier)
{
struct t7xx_fsm_ctl *ctl = md->fsm_ctl;
unsigned long flags;
spin_lock_irqsave(&ctl->notifier_lock, flags);
list_add_tail(&notifier->entry, &ctl->notifier_list);
spin_unlock_irqrestore(&ctl->notifier_lock, flags);
}
void t7xx_fsm_notifier_unregister(struct t7xx_modem *md, struct t7xx_fsm_notifier *notifier)
{
struct t7xx_fsm_notifier *notifier_cur, *notifier_next;
struct t7xx_fsm_ctl *ctl = md->fsm_ctl;
unsigned long flags;
spin_lock_irqsave(&ctl->notifier_lock, flags);
list_for_each_entry_safe(notifier_cur, notifier_next, &ctl->notifier_list, entry) {
if (notifier_cur == notifier)
list_del(&notifier->entry);
}
spin_unlock_irqrestore(&ctl->notifier_lock, flags);
}
static void fsm_state_notify(struct t7xx_modem *md, enum md_state state)
{
struct t7xx_fsm_ctl *ctl = md->fsm_ctl;
struct t7xx_fsm_notifier *notifier;
unsigned long flags;
spin_lock_irqsave(&ctl->notifier_lock, flags);
list_for_each_entry(notifier, &ctl->notifier_list, entry) {
spin_unlock_irqrestore(&ctl->notifier_lock, flags);
if (notifier->notifier_fn)
notifier->notifier_fn(state, notifier->data);
spin_lock_irqsave(&ctl->notifier_lock, flags);
}
spin_unlock_irqrestore(&ctl->notifier_lock, flags);
}
void t7xx_fsm_broadcast_state(struct t7xx_fsm_ctl *ctl, enum md_state state)
{
ctl->md_state = state;
/* Update to port first, otherwise sending message on HS2 may fail */
t7xx_port_proxy_md_status_notify(ctl->md->port_prox, state);
fsm_state_notify(ctl->md, state);
}
static void fsm_finish_command(struct t7xx_fsm_ctl *ctl, struct t7xx_fsm_command *cmd, int result)
{
if (cmd->flag & FSM_CMD_FLAG_WAIT_FOR_COMPLETION) {
*cmd->ret = result;
complete_all(cmd->done);
}
kfree(cmd);
}
static void fsm_del_kf_event(struct t7xx_fsm_event *event)
{
list_del(&event->entry);
kfree(event);
}
static void fsm_flush_event_cmd_qs(struct t7xx_fsm_ctl *ctl)
{
struct device *dev = &ctl->md->t7xx_dev->pdev->dev;
struct t7xx_fsm_event *event, *evt_next;
struct t7xx_fsm_command *cmd, *cmd_next;
unsigned long flags;
spin_lock_irqsave(&ctl->command_lock, flags);
list_for_each_entry_safe(cmd, cmd_next, &ctl->command_queue, entry) {
dev_warn(dev, "Unhandled command %d\n", cmd->cmd_id);
list_del(&cmd->entry);
fsm_finish_command(ctl, cmd, -EINVAL);
}
spin_unlock_irqrestore(&ctl->command_lock, flags);
spin_lock_irqsave(&ctl->event_lock, flags);
list_for_each_entry_safe(event, evt_next, &ctl->event_queue, entry) {
dev_warn(dev, "Unhandled event %d\n", event->event_id);
fsm_del_kf_event(event);
}
spin_unlock_irqrestore(&ctl->event_lock, flags);
}
static void fsm_wait_for_event(struct t7xx_fsm_ctl *ctl, enum t7xx_fsm_event_state event_expected,
enum t7xx_fsm_event_state event_ignore, int retries)
{
struct t7xx_fsm_event *event;
bool event_received = false;
unsigned long flags;
int cnt = 0;
while (cnt++ < retries && !event_received) {
bool sleep_required = true;
if (kthread_should_stop())
return;
spin_lock_irqsave(&ctl->event_lock, flags);
event = list_first_entry_or_null(&ctl->event_queue, struct t7xx_fsm_event, entry);
if (event) {
event_received = event->event_id == event_expected;
if (event_received || event->event_id == event_ignore) {
fsm_del_kf_event(event);
sleep_required = false;
}
}
spin_unlock_irqrestore(&ctl->event_lock, flags);
if (sleep_required)
msleep(FSM_EVENT_POLL_INTERVAL_MS);
}
}
static void fsm_routine_exception(struct t7xx_fsm_ctl *ctl, struct t7xx_fsm_command *cmd,
enum t7xx_ex_reason reason)
{
struct device *dev = &ctl->md->t7xx_dev->pdev->dev;
if (ctl->curr_state != FSM_STATE_READY && ctl->curr_state != FSM_STATE_STARTING) {
if (cmd)
fsm_finish_command(ctl, cmd, -EINVAL);
return;
}
ctl->curr_state = FSM_STATE_EXCEPTION;
switch (reason) {
case EXCEPTION_HS_TIMEOUT:
dev_err(dev, "Boot Handshake failure\n");
break;
case EXCEPTION_EVENT:
dev_err(dev, "Exception event\n");
t7xx_fsm_broadcast_state(ctl, MD_STATE_EXCEPTION);
t7xx_pci_pm_exp_detected(ctl->md->t7xx_dev);
t7xx_md_exception_handshake(ctl->md);
fsm_wait_for_event(ctl, FSM_EVENT_MD_EX_REC_OK, FSM_EVENT_MD_EX,
FSM_MD_EX_REC_OK_TIMEOUT_MS / FSM_EVENT_POLL_INTERVAL_MS);
fsm_wait_for_event(ctl, FSM_EVENT_MD_EX_PASS, FSM_EVENT_INVALID,
FSM_MD_EX_PASS_TIMEOUT_MS / FSM_EVENT_POLL_INTERVAL_MS);
break;
default:
dev_err(dev, "Exception %d\n", reason);
break;
}
if (cmd)
fsm_finish_command(ctl, cmd, 0);
}
static void t7xx_lk_stage_event_handling(struct t7xx_fsm_ctl *ctl, unsigned int status)
{
struct t7xx_modem *md = ctl->md;
struct cldma_ctrl *md_ctrl;
enum lk_event_id lk_event;
struct device *dev;
struct t7xx_port *port;
dev = &md->t7xx_dev->pdev->dev;
lk_event = FIELD_GET(MISC_LK_EVENT_MASK, status);
switch (lk_event) {
case LK_EVENT_NORMAL:
case LK_EVENT_RESET:
break;
case LK_EVENT_CREATE_PD_PORT:
case LK_EVENT_CREATE_POST_DL_PORT:
md_ctrl = md->md_ctrl[CLDMA_ID_AP];
t7xx_cldma_hif_hw_init(md_ctrl);
t7xx_cldma_stop(md_ctrl);
t7xx_cldma_switch_cfg(md_ctrl, CLDMA_DEDICATED_Q_CFG);
port = &ctl->md->port_prox->ports[0];
port->port_conf->ops->enable_chl(port);
t7xx_cldma_start(md_ctrl);
if (lk_event == LK_EVENT_CREATE_POST_DL_PORT)
t7xx_mode_update(md->t7xx_dev, T7XX_FASTBOOT_DOWNLOAD);
else
t7xx_mode_update(md->t7xx_dev, T7XX_FASTBOOT_DUMP);
break;
default:
dev_err(dev, "Invalid LK event %d\n", lk_event);
break;
}
}
static int fsm_stopped_handler(struct t7xx_fsm_ctl *ctl)
{
enum t7xx_mode mode;
ctl->curr_state = FSM_STATE_STOPPED;
mode = READ_ONCE(ctl->md->t7xx_dev->mode);
if (mode == T7XX_FASTBOOT_DOWNLOAD || mode == T7XX_FASTBOOT_DUMP)
return 0;
t7xx_fsm_broadcast_state(ctl, MD_STATE_STOPPED);
return t7xx_md_reset(ctl->md->t7xx_dev);
}
static void fsm_routine_stopped(struct t7xx_fsm_ctl *ctl, struct t7xx_fsm_command *cmd)
{
if (ctl->curr_state == FSM_STATE_STOPPED) {
fsm_finish_command(ctl, cmd, -EINVAL);
return;
}
fsm_finish_command(ctl, cmd, fsm_stopped_handler(ctl));
}
static void fsm_routine_stopping(struct t7xx_fsm_ctl *ctl, struct t7xx_fsm_command *cmd)
{
struct cldma_ctrl *md_ctrl = ctl->md->md_ctrl[CLDMA_ID_MD];
struct t7xx_pci_dev *t7xx_dev = ctl->md->t7xx_dev;
if (ctl->curr_state == FSM_STATE_STOPPED || ctl->curr_state == FSM_STATE_STOPPING) {
fsm_finish_command(ctl, cmd, -EINVAL);
return;
}
ctl->curr_state = FSM_STATE_STOPPING;
t7xx_fsm_broadcast_state(ctl, MD_STATE_WAITING_TO_STOP);
t7xx_cldma_stop(md_ctrl);
t7xx_mhccif_h2d_swint_trigger(t7xx_dev, H2D_CH_DRM_DISABLE_AP);
/* Wait for the DRM disable to take effect */
msleep(FSM_DRM_DISABLE_DELAY_MS);
fsm_finish_command(ctl, cmd, fsm_stopped_handler(ctl));
}
static void t7xx_fsm_broadcast_ready_state(struct t7xx_fsm_ctl *ctl)
{
if (ctl->md_state != MD_STATE_WAITING_FOR_HS2)
return;
ctl->md_state = MD_STATE_READY;
fsm_state_notify(ctl->md, MD_STATE_READY);
t7xx_port_proxy_md_status_notify(ctl->md->port_prox, MD_STATE_READY);
}
static void fsm_routine_ready(struct t7xx_fsm_ctl *ctl)
{
struct t7xx_modem *md = ctl->md;
ctl->curr_state = FSM_STATE_READY;
t7xx_fsm_broadcast_ready_state(ctl);
t7xx_mode_update(md->t7xx_dev, T7XX_READY);
t7xx_md_event_notify(md, FSM_READY);
}
static int fsm_routine_starting(struct t7xx_fsm_ctl *ctl)
{
struct t7xx_modem *md = ctl->md;
struct device *dev;
ctl->curr_state = FSM_STATE_STARTING;
t7xx_fsm_broadcast_state(ctl, MD_STATE_WAITING_FOR_HS1);
t7xx_md_event_notify(md, FSM_START);
wait_event_interruptible_timeout(ctl->async_hk_wq,
(md->core_md.ready && md->core_ap.ready) ||
ctl->exp_flg, HZ * 60);
dev = &md->t7xx_dev->pdev->dev;
if (ctl->exp_flg)
dev_err(dev, "MD exception is captured during handshake\n");
if (!md->core_md.ready) {
dev_err(dev, "MD handshake timeout\n");
if (md->core_md.handshake_ongoing)
t7xx_fsm_append_event(ctl, FSM_EVENT_MD_HS2_EXIT, NULL, 0);
fsm_routine_exception(ctl, NULL, EXCEPTION_HS_TIMEOUT);
return -ETIMEDOUT;
} else if (!md->core_ap.ready) {
dev_err(dev, "AP handshake timeout\n");
if (md->core_ap.handshake_ongoing)
t7xx_fsm_append_event(ctl, FSM_EVENT_AP_HS2_EXIT, NULL, 0);
fsm_routine_exception(ctl, NULL, EXCEPTION_HS_TIMEOUT);
return -ETIMEDOUT;
}
t7xx_pci_pm_init_late(md->t7xx_dev);
fsm_routine_ready(ctl);
return 0;
}
static void fsm_routine_start(struct t7xx_fsm_ctl *ctl, struct t7xx_fsm_command *cmd)
{
struct t7xx_modem *md = ctl->md;
struct device *dev;
u32 status;
int ret;
if (!md)
return;
if (ctl->curr_state != FSM_STATE_INIT && ctl->curr_state != FSM_STATE_PRE_START &&
ctl->curr_state != FSM_STATE_STOPPED) {
fsm_finish_command(ctl, cmd, -EINVAL);
return;
}
dev = &md->t7xx_dev->pdev->dev;
ctl->curr_state = FSM_STATE_PRE_START;
t7xx_md_event_notify(md, FSM_PRE_START);
ret = wait_for_expected_dev_stage(status);
if (ret) {
dev_err(dev, "read poll timeout %d\n", ret);
goto finish_command;
}
if (status != ctl->status || cmd->flag != 0) {
u32 stage = FIELD_GET(MISC_STAGE_MASK, status);
switch (stage) {
case T7XX_DEV_STAGE_INIT:
case T7XX_DEV_STAGE_BROM_PRE:
case T7XX_DEV_STAGE_BROM_POST:
dev_dbg(dev, "BROM_STAGE Entered\n");
ret = t7xx_fsm_append_cmd(ctl, FSM_CMD_START, 0);
break;
case T7XX_DEV_STAGE_LK:
dev_dbg(dev, "LK_STAGE Entered\n");
t7xx_port_proxy_set_cfg(md, PORT_CFG_ID_EARLY);
t7xx_lk_stage_event_handling(ctl, status);
break;
case T7XX_DEV_STAGE_LINUX:
dev_dbg(dev, "LINUX_STAGE Entered\n");
t7xx_mhccif_mask_clr(md->t7xx_dev, D2H_INT_PORT_ENUM |
D2H_INT_ASYNC_MD_HK | D2H_INT_ASYNC_AP_HK);
if (cmd->flag == 0)
break;
t7xx_cldma_hif_hw_init(md->md_ctrl[CLDMA_ID_AP]);
t7xx_cldma_hif_hw_init(md->md_ctrl[CLDMA_ID_MD]);
t7xx_port_proxy_set_cfg(md, PORT_CFG_ID_NORMAL);
ret = fsm_routine_starting(ctl);
break;
default:
break;
}
ctl->status = status;
}
finish_command:
if (ret)
t7xx_mode_update(md->t7xx_dev, T7XX_UNKNOWN);
fsm_finish_command(ctl, cmd, ret);
}
static int fsm_main_thread(void *data)
{
struct t7xx_fsm_ctl *ctl = data;
struct t7xx_fsm_command *cmd;
unsigned long flags;
while (!kthread_should_stop()) {
if (wait_event_interruptible(ctl->command_wq, !list_empty(&ctl->command_queue) ||
kthread_should_stop()))
continue;
if (kthread_should_stop())
break;
spin_lock_irqsave(&ctl->command_lock, flags);
cmd = list_first_entry(&ctl->command_queue, struct t7xx_fsm_command, entry);
list_del(&cmd->entry);
spin_unlock_irqrestore(&ctl->command_lock, flags);
switch (cmd->cmd_id) {
case FSM_CMD_START:
fsm_routine_start(ctl, cmd);
break;
case FSM_CMD_EXCEPTION:
fsm_routine_exception(ctl, cmd, FIELD_GET(FSM_CMD_EX_REASON, cmd->flag));
break;
case FSM_CMD_PRE_STOP:
fsm_routine_stopping(ctl, cmd);
break;
case FSM_CMD_STOP:
fsm_routine_stopped(ctl, cmd);
break;
default:
fsm_finish_command(ctl, cmd, -EINVAL);
fsm_flush_event_cmd_qs(ctl);
break;
}
}
return 0;
}
int t7xx_fsm_append_cmd(struct t7xx_fsm_ctl *ctl, enum t7xx_fsm_cmd_state cmd_id, unsigned int flag)
{
DECLARE_COMPLETION_ONSTACK(done);
struct t7xx_fsm_command *cmd;
unsigned long flags;
int ret;
cmd = kzalloc(sizeof(*cmd), flag & FSM_CMD_FLAG_IN_INTERRUPT ? GFP_ATOMIC : GFP_KERNEL);
if (!cmd)
return -ENOMEM;
INIT_LIST_HEAD(&cmd->entry);
cmd->cmd_id = cmd_id;
cmd->flag = flag;
if (flag & FSM_CMD_FLAG_WAIT_FOR_COMPLETION) {
cmd->done = &done;
cmd->ret = &ret;
}
spin_lock_irqsave(&ctl->command_lock, flags);
list_add_tail(&cmd->entry, &ctl->command_queue);
spin_unlock_irqrestore(&ctl->command_lock, flags);
wake_up(&ctl->command_wq);
if (flag & FSM_CMD_FLAG_WAIT_FOR_COMPLETION) {
unsigned long wait_ret;
wait_ret = wait_for_completion_timeout(&done,
msecs_to_jiffies(FSM_CMD_TIMEOUT_MS));
if (!wait_ret)
return -ETIMEDOUT;
return ret;
}
return 0;
}
int t7xx_fsm_append_event(struct t7xx_fsm_ctl *ctl, enum t7xx_fsm_event_state event_id,
unsigned char *data, unsigned int length)
{
struct device *dev = &ctl->md->t7xx_dev->pdev->dev;
struct t7xx_fsm_event *event;
unsigned long flags;
if (event_id <= FSM_EVENT_INVALID || event_id >= FSM_EVENT_MAX) {
dev_err(dev, "Invalid event %d\n", event_id);
return -EINVAL;
}
event = kmalloc(struct_size(event, data, length),
in_interrupt() ? GFP_ATOMIC : GFP_KERNEL);
if (!event)
return -ENOMEM;
INIT_LIST_HEAD(&event->entry);
event->event_id = event_id;
event->length = length;
if (data && length)
memcpy(event->data, data, length);
spin_lock_irqsave(&ctl->event_lock, flags);
list_add_tail(&event->entry, &ctl->event_queue);
spin_unlock_irqrestore(&ctl->event_lock, flags);
wake_up_all(&ctl->event_wq);
return 0;
}
void t7xx_fsm_clr_event(struct t7xx_fsm_ctl *ctl, enum t7xx_fsm_event_state event_id)
{
struct t7xx_fsm_event *event, *evt_next;
unsigned long flags;
spin_lock_irqsave(&ctl->event_lock, flags);
list_for_each_entry_safe(event, evt_next, &ctl->event_queue, entry) {
if (event->event_id == event_id)
fsm_del_kf_event(event);
}
spin_unlock_irqrestore(&ctl->event_lock, flags);
}
enum md_state t7xx_fsm_get_md_state(struct t7xx_fsm_ctl *ctl)
{
if (ctl)
return ctl->md_state;
return MD_STATE_INVALID;
}
unsigned int t7xx_fsm_get_ctl_state(struct t7xx_fsm_ctl *ctl)
{
if (ctl)
return ctl->curr_state;
return FSM_STATE_STOPPED;
}
int t7xx_fsm_recv_md_intr(struct t7xx_fsm_ctl *ctl, enum t7xx_md_irq_type type)
{
unsigned int cmd_flags = FSM_CMD_FLAG_IN_INTERRUPT;
if (type == MD_IRQ_PORT_ENUM) {
return t7xx_fsm_append_cmd(ctl, FSM_CMD_START, cmd_flags);
} else if (type == MD_IRQ_CCIF_EX) {
ctl->exp_flg = true;
wake_up(&ctl->async_hk_wq);
cmd_flags |= FIELD_PREP(FSM_CMD_EX_REASON, EXCEPTION_EVENT);
return t7xx_fsm_append_cmd(ctl, FSM_CMD_EXCEPTION, cmd_flags);
}
return -EINVAL;
}
void t7xx_fsm_reset(struct t7xx_modem *md)
{
struct t7xx_fsm_ctl *ctl = md->fsm_ctl;
fsm_flush_event_cmd_qs(ctl);
ctl->curr_state = FSM_STATE_STOPPED;
ctl->exp_flg = false;
ctl->status = T7XX_DEV_STAGE_INIT;
}
int t7xx_fsm_init(struct t7xx_modem *md)
{
struct device *dev = &md->t7xx_dev->pdev->dev;
struct t7xx_fsm_ctl *ctl;
ctl = devm_kzalloc(dev, sizeof(*ctl), GFP_KERNEL);
if (!ctl)
return -ENOMEM;
md->fsm_ctl = ctl;
ctl->md = md;
ctl->curr_state = FSM_STATE_INIT;
INIT_LIST_HEAD(&ctl->command_queue);
INIT_LIST_HEAD(&ctl->event_queue);
init_waitqueue_head(&ctl->async_hk_wq);
init_waitqueue_head(&ctl->event_wq);
INIT_LIST_HEAD(&ctl->notifier_list);
init_waitqueue_head(&ctl->command_wq);
spin_lock_init(&ctl->event_lock);
spin_lock_init(&ctl->command_lock);
ctl->exp_flg = false;
spin_lock_init(&ctl->notifier_lock);
ctl->fsm_thread = kthread_run(fsm_main_thread, ctl, "t7xx_fsm");
return PTR_ERR_OR_ZERO(ctl->fsm_thread);
}
void t7xx_fsm_uninit(struct t7xx_modem *md)
{
struct t7xx_fsm_ctl *ctl = md->fsm_ctl;
if (!ctl)
return;
if (ctl->fsm_thread)
kthread_stop(ctl->fsm_thread);
fsm_flush_event_cmd_qs(ctl);
}
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