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misc: bcm-vk: reset_pid support
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Add reset support via ioctl.
Kill user processes that are open when VK card is reset.
If a particular PID has issued the reset request do not kill that process
as it issued the ioctl.

Co-developed-by: Desmond Yan <[email protected]>
Acked-by: Olof Johansson <[email protected]>
Signed-off-by: Desmond Yan <[email protected]>
Signed-off-by: Scott Branden <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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@sbranden @gregkh
sbranden authored and gregkh committed Jan 25, 2021
1 parent 111d746 commit d63d658
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Showing 3 changed files with 191 additions and 8 deletions.
1 change: 1 addition & 0 deletions drivers/misc/bcm-vk/bcm_vk.h
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Original file line number Diff line number Diff line change
Expand Up @@ -468,6 +468,7 @@ irqreturn_t bcm_vk_msgq_irqhandler(int irq, void *dev_id);
irqreturn_t bcm_vk_notf_irqhandler(int irq, void *dev_id);
int bcm_vk_msg_init(struct bcm_vk *vk);
void bcm_vk_msg_remove(struct bcm_vk *vk);
void bcm_vk_drain_msg_on_reset(struct bcm_vk *vk);
int bcm_vk_sync_msgq(struct bcm_vk *vk, bool force_sync);
void bcm_vk_blk_drv_access(struct bcm_vk *vk);
s32 bcm_to_h_msg_dequeue(struct bcm_vk *vk);
Expand Down
158 changes: 152 additions & 6 deletions drivers/misc/bcm-vk/bcm_vk_dev.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -504,7 +504,9 @@ void bcm_vk_blk_drv_access(struct bcm_vk *vk)
int i;

/*
* kill all the apps
* kill all the apps except for the process that is resetting.
* If not called during reset, reset_pid will be 0, and all will be
* killed.
*/
spin_lock(&vk->ctx_lock);

Expand All @@ -515,10 +517,12 @@ void bcm_vk_blk_drv_access(struct bcm_vk *vk)
struct bcm_vk_ctx *ctx;

list_for_each_entry(ctx, &vk->pid_ht[i].head, node) {
dev_dbg(&vk->pdev->dev,
"Send kill signal to pid %d\n",
ctx->pid);
kill_pid(find_vpid(ctx->pid), SIGKILL, 1);
if (ctx->pid != vk->reset_pid) {
dev_dbg(&vk->pdev->dev,
"Send kill signal to pid %d\n",
ctx->pid);
kill_pid(find_vpid(ctx->pid), SIGKILL, 1);
}
}
}
spin_unlock(&vk->ctx_lock);
Expand Down Expand Up @@ -1001,6 +1005,49 @@ static long bcm_vk_load_image(struct bcm_vk *vk,
return ret;
}

static int bcm_vk_reset_successful(struct bcm_vk *vk)
{
struct device *dev = &vk->pdev->dev;
u32 fw_status, reset_reason;
int ret = -EAGAIN;

/*
* Reset could be triggered when the card in several state:
* i) in bootROM
* ii) after boot1
* iii) boot2 running
*
* i) & ii) - no status bits will be updated. If vkboot1
* runs automatically after reset, it will update the reason
* to be unknown reason
* iii) - reboot reason match + deinit done.
*/
fw_status = vkread32(vk, BAR_0, VK_BAR_FWSTS);
/* immediate exit if interface goes down */
if (BCM_VK_INTF_IS_DOWN(fw_status)) {
dev_err(dev, "PCIe Intf Down!\n");
goto reset_exit;
}

reset_reason = (fw_status & VK_FWSTS_RESET_REASON_MASK);
if ((reset_reason == VK_FWSTS_RESET_MBOX_DB) ||
(reset_reason == VK_FWSTS_RESET_UNKNOWN))
ret = 0;

/*
* if some of the deinit bits are set, but done
* bit is not, this is a failure if triggered while boot2 is running
*/
if ((fw_status & VK_FWSTS_DEINIT_TRIGGERED) &&
!(fw_status & VK_FWSTS_RESET_DONE))
ret = -EAGAIN;

reset_exit:
dev_dbg(dev, "FW status = 0x%x ret %d\n", fw_status, ret);

return ret;
}

static void bcm_to_v_reset_doorbell(struct bcm_vk *vk, u32 db_val)
{
vkwrite32(vk, db_val, BAR_0, VK_BAR0_RESET_DB_BASE);
Expand All @@ -1010,12 +1057,16 @@ static int bcm_vk_trigger_reset(struct bcm_vk *vk)
{
u32 i;
u32 value, boot_status;
bool is_stdalone, is_boot2;
static const u32 bar0_reg_clr_list[] = { BAR_OS_UPTIME,
BAR_INTF_VER,
BAR_CARD_VOLTAGE,
BAR_CARD_TEMPERATURE,
BAR_CARD_PWR_AND_THRE };

/* clean up before pressing the door bell */
bcm_vk_drain_msg_on_reset(vk);
vkwrite32(vk, 0, BAR_1, VK_BAR1_MSGQ_DEF_RDY);
/* make tag '\0' terminated */
vkwrite32(vk, 0, BAR_1, VK_BAR1_BOOT1_VER_TAG);

Expand All @@ -1026,6 +1077,11 @@ static int bcm_vk_trigger_reset(struct bcm_vk *vk)
for (i = 0; i < VK_BAR1_SOTP_REVID_MAX; i++)
vkwrite32(vk, 0, BAR_1, VK_BAR1_SOTP_REVID_ADDR(i));

memset(&vk->card_info, 0, sizeof(vk->card_info));
memset(&vk->peerlog_info, 0, sizeof(vk->peerlog_info));
memset(&vk->proc_mon_info, 0, sizeof(vk->proc_mon_info));
memset(&vk->alert_cnts, 0, sizeof(vk->alert_cnts));

/*
* When boot request fails, the CODE_PUSH_OFFSET stays persistent.
* Allowing us to debug the failure. When we call reset,
Expand All @@ -1046,17 +1102,103 @@ static int bcm_vk_trigger_reset(struct bcm_vk *vk)
}
vkwrite32(vk, value, BAR_0, BAR_CODEPUSH_SBL);

/* special reset handling */
is_stdalone = boot_status & BOOT_STDALONE_RUNNING;
is_boot2 = (boot_status & BOOT_STATE_MASK) == BOOT2_RUNNING;
if (vk->peer_alert.flags & ERR_LOG_RAMDUMP) {
/*
* if card is in ramdump mode, it is hitting an error. Don't
* reset the reboot reason as it will contain valid info that
* is important - simply use special reset
*/
vkwrite32(vk, VK_BAR0_RESET_RAMPDUMP, BAR_0, VK_BAR_FWSTS);
return VK_BAR0_RESET_RAMPDUMP;
} else if (is_stdalone && !is_boot2) {
dev_info(&vk->pdev->dev, "Hard reset on Standalone mode");
bcm_to_v_reset_doorbell(vk, VK_BAR0_RESET_DB_HARD);
return VK_BAR0_RESET_DB_HARD;
}

/* reset fw_status with proper reason, and press db */
vkwrite32(vk, VK_FWSTS_RESET_MBOX_DB, BAR_0, VK_BAR_FWSTS);
bcm_to_v_reset_doorbell(vk, VK_BAR0_RESET_DB_SOFT);

/* clear other necessary registers records */
/* clear other necessary registers and alert records */
for (i = 0; i < ARRAY_SIZE(bar0_reg_clr_list); i++)
vkwrite32(vk, 0, BAR_0, bar0_reg_clr_list[i]);
memset(&vk->host_alert, 0, sizeof(vk->host_alert));
memset(&vk->peer_alert, 0, sizeof(vk->peer_alert));
/* clear 4096 bits of bitmap */
bitmap_clear(vk->bmap, 0, VK_MSG_ID_BITMAP_SIZE);

return 0;
}

static long bcm_vk_reset(struct bcm_vk *vk, struct vk_reset __user *arg)
{
struct device *dev = &vk->pdev->dev;
struct vk_reset reset;
int ret = 0;
u32 ramdump_reset;
int special_reset;

if (copy_from_user(&reset, arg, sizeof(struct vk_reset)))
return -EFAULT;

/* check if any download is in-progress, if so return error */
if (test_and_set_bit(BCM_VK_WQ_DWNLD_PEND, vk->wq_offload) != 0) {
dev_err(dev, "Download operation pending - skip reset.\n");
return -EPERM;
}

ramdump_reset = vk->peer_alert.flags & ERR_LOG_RAMDUMP;
dev_info(dev, "Issue Reset %s\n",
ramdump_reset ? "in ramdump mode" : "");

/*
* The following is the sequence of reset:
* - send card level graceful shut down
* - wait enough time for VK to handle its business, stopping DMA etc
* - kill host apps
* - Trigger interrupt with DB
*/
bcm_vk_send_shutdown_msg(vk, VK_SHUTDOWN_GRACEFUL, 0, 0);

spin_lock(&vk->ctx_lock);
if (!vk->reset_pid) {
vk->reset_pid = task_pid_nr(current);
} else {
dev_err(dev, "Reset already launched by process pid %d\n",
vk->reset_pid);
ret = -EACCES;
}
spin_unlock(&vk->ctx_lock);
if (ret)
goto err_exit;

bcm_vk_blk_drv_access(vk);
special_reset = bcm_vk_trigger_reset(vk);

/*
* Wait enough time for card os to deinit
* and populate the reset reason.
*/
msleep(BCM_VK_DEINIT_TIME_MS);

if (special_reset) {
/* if it is special ramdump reset, return the type to user */
reset.arg2 = special_reset;
if (copy_to_user(arg, &reset, sizeof(reset)))
ret = -EFAULT;
} else {
ret = bcm_vk_reset_successful(vk);
}

err_exit:
clear_bit(BCM_VK_WQ_DWNLD_PEND, vk->wq_offload);
return ret;
}

static long bcm_vk_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
long ret = -EINVAL;
Expand All @@ -1075,6 +1217,10 @@ static long bcm_vk_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
ret = bcm_vk_load_image(vk, argp);
break;

case VK_IOCTL_RESET:
ret = bcm_vk_reset(vk, argp);
break;

default:
break;
}
Expand Down
40 changes: 38 additions & 2 deletions drivers/misc/bcm-vk/bcm_vk_msg.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -209,6 +209,15 @@ static struct bcm_vk_ctx *bcm_vk_get_ctx(struct bcm_vk *vk, const pid_t pid)

spin_lock(&vk->ctx_lock);

/* check if it is in reset, if so, don't allow */
if (vk->reset_pid) {
dev_err(&vk->pdev->dev,
"No context allowed during reset by pid %d\n",
vk->reset_pid);

goto in_reset_exit;
}

for (i = 0; i < ARRAY_SIZE(vk->ctx); i++) {
if (!vk->ctx[i].in_use) {
vk->ctx[i].in_use = true;
Expand Down Expand Up @@ -237,6 +246,7 @@ static struct bcm_vk_ctx *bcm_vk_get_ctx(struct bcm_vk *vk, const pid_t pid)
init_waitqueue_head(&ctx->rd_wq);

all_in_use_exit:
in_reset_exit:
spin_unlock(&vk->ctx_lock);

return ctx;
Expand Down Expand Up @@ -381,6 +391,12 @@ static void bcm_vk_drain_all_pend(struct device *dev,
num, ctx->idx);
}

void bcm_vk_drain_msg_on_reset(struct bcm_vk *vk)
{
bcm_vk_drain_all_pend(&vk->pdev->dev, &vk->to_v_msg_chan, NULL);
bcm_vk_drain_all_pend(&vk->pdev->dev, &vk->to_h_msg_chan, NULL);
}

/*
* Function to sync up the messages queue info that is provided by BAR1
*/
Expand Down Expand Up @@ -712,13 +728,22 @@ static int bcm_vk_handle_last_sess(struct bcm_vk *vk, const pid_t pid,

/*
* don't send down or do anything if message queue is not initialized
* and if it is the reset session, clear it.
*/
if (!bcm_vk_drv_access_ok(vk))
if (!bcm_vk_drv_access_ok(vk)) {
if (vk->reset_pid == pid)
vk->reset_pid = 0;
return -EPERM;
}

dev_dbg(dev, "No more sessions, shut down pid %d\n", pid);

rc = bcm_vk_send_shutdown_msg(vk, VK_SHUTDOWN_PID, pid, q_num);
/* only need to do it if it is not the reset process */
if (vk->reset_pid != pid)
rc = bcm_vk_send_shutdown_msg(vk, VK_SHUTDOWN_PID, pid, q_num);
else
/* put reset_pid to 0 if it is exiting last session */
vk->reset_pid = 0;

return rc;
}
Expand Down Expand Up @@ -1122,6 +1147,17 @@ ssize_t bcm_vk_write(struct file *p_file,
int dir;
struct _vk_data *data;

/*
* check if we are in reset, if so, no buffer transfer is
* allowed and return error.
*/
if (vk->reset_pid) {
dev_dbg(dev, "No Transfer allowed during reset, pid %d.\n",
ctx->pid);
rc = -EACCES;
goto write_free_msgid;
}

num_planes = entry->to_v_msg[0].cmd & VK_CMD_PLANES_MASK;
if ((entry->to_v_msg[0].cmd & VK_CMD_MASK) == VK_CMD_DOWNLOAD)
dir = DMA_FROM_DEVICE;
Expand Down

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