// SPDX-License-Identifier: GPL-2.0
/*
* Copyright 2018-2020 Broadcom.
*/
#include <linux/delay.h>
#include <linux/fs.h>
#include <linux/hash.h>
#include <linux/interrupt.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/poll.h>
#include <linux/sizes.h>
#include <linux/spinlock.h>
#include <linux/timer.h>
#include "bcm_vk.h"
#include "bcm_vk_msg.h"
#include "bcm_vk_sg.h"
/* functions to manipulate the transport id in msg block */
#define BCM_VK_MSG_Q_SHIFT 4
#define BCM_VK_MSG_Q_MASK 0xF
#define BCM_VK_MSG_ID_MASK 0xFFF
#define BCM_VK_DMA_DRAIN_MAX_MS 2000
/* number x q_size will be the max number of msg processed per loop */
#define BCM_VK_MSG_PROC_MAX_LOOP 2
/* module parameter */
static bool hb_mon = true;
module_param(hb_mon, bool, 0444);
MODULE_PARM_DESC(hb_mon, "Monitoring heartbeat continuously.\n");
static int batch_log = 1;
module_param(batch_log, int, 0444);
MODULE_PARM_DESC(batch_log, "Max num of logs per batch operation.\n");
static bool hb_mon_is_on(void)
{
return hb_mon;
}
static u32 get_q_num(const struct vk_msg_blk *msg)
{
u32 q_num = msg->trans_id & BCM_VK_MSG_Q_MASK;
if (q_num >= VK_MSGQ_PER_CHAN_MAX)
q_num = VK_MSGQ_NUM_DEFAULT;
return q_num;
}
static void set_q_num(struct vk_msg_blk *msg, u32 q_num)
{
u32 trans_q;
if (q_num >= VK_MSGQ_PER_CHAN_MAX)
trans_q = VK_MSGQ_NUM_DEFAULT;
else
trans_q = q_num;
msg->trans_id = (msg->trans_id & ~BCM_VK_MSG_Q_MASK) | trans_q;
}
static u32 get_msg_id(const struct vk_msg_blk *msg)
{
return ((msg->trans_id >> BCM_VK_MSG_Q_SHIFT) & BCM_VK_MSG_ID_MASK);
}
static void set_msg_id(struct vk_msg_blk *msg, u32 val)
{
msg->trans_id = (val << BCM_VK_MSG_Q_SHIFT) | get_q_num(msg);
}
static u32 msgq_inc(const struct bcm_vk_sync_qinfo *qinfo, u32 idx, u32 inc)
{
return ((idx + inc) & qinfo->q_mask);
}
static
struct vk_msg_blk __iomem *msgq_blk_addr(const struct bcm_vk_sync_qinfo *qinfo,
u32 idx)
{
return qinfo->q_start + (VK_MSGQ_BLK_SIZE * idx);
}
static u32 msgq_occupied(const struct bcm_vk_msgq __iomem *msgq,
const struct bcm_vk_sync_qinfo *qinfo)
{
u32 wr_idx, rd_idx;
wr_idx = readl_relaxed(&msgq->wr_idx);
rd_idx = readl_relaxed(&msgq->rd_idx);
return ((wr_idx - rd_idx) & qinfo->q_mask);
}
static
u32 msgq_avail_space(const struct bcm_vk_msgq __iomem *msgq,
const struct bcm_vk_sync_qinfo *qinfo)
{
return (qinfo->q_size - msgq_occupied(msgq, qinfo) - 1);
}
/* number of retries when enqueue message fails before returning EAGAIN */
#define BCM_VK_H2VK_ENQ_RETRY 10
#define BCM_VK_H2VK_ENQ_RETRY_DELAY_MS 50
bool bcm_vk_drv_access_ok(struct bcm_vk *vk)
{
return (!!atomic_read(&vk->msgq_inited));
}
void bcm_vk_set_host_alert(struct bcm_vk *vk, u32 bit_mask)
{
struct bcm_vk_alert *alert = &vk->host_alert;
unsigned long flags;
/* use irqsave version as this maybe called inside timer interrupt */
spin_lock_irqsave(&vk->host_alert_lock, flags);
alert->notfs |= bit_mask;
spin_unlock_irqrestore(&vk->host_alert_lock, flags);
if (test_and_set_bit(BCM_VK_WQ_NOTF_PEND, vk->wq_offload) == 0)
queue_work(vk->wq_thread, &vk->wq_work);
}
/*
* Heartbeat related defines
* The heartbeat from host is a last resort. If stuck condition happens
* on the card, firmware is supposed to detect it. Therefore, the heartbeat
* values used will be more relaxed on the driver, which need to be bigger
* than the watchdog timeout on the card. The watchdog timeout on the card
* is 20s, with a jitter of 2s => 22s. We use a value of 27s here.
*/
#define BCM_VK_HB_TIMER_S 3
#define BCM_VK_HB_TIMER_VALUE (BCM_VK_HB_TIMER_S * HZ)
#define BCM_VK_HB_LOST_MAX (27 / BCM_VK_HB_TIMER_S)
static void bcm_vk_hb_poll(struct work_struct *work)
{
u32 uptime_s;
struct bcm_vk_hb_ctrl *hb = container_of(to_delayed_work(work), struct bcm_vk_hb_ctrl,
work);
struct bcm_vk *vk = container_of(hb, struct bcm_vk, hb_ctrl);
if (bcm_vk_drv_access_ok(vk) && hb_mon_is_on()) {
/* read uptime from register and compare */
uptime_s = vkread32(vk, BAR_0, BAR_OS_UPTIME);
if (uptime_s == hb->last_uptime)
hb->lost_cnt++;
else /* reset to avoid accumulation */
hb->lost_cnt = 0;
dev_dbg(&vk->pdev->dev, "Last uptime %d current %d, lost %d\n",
hb->last_uptime, uptime_s, hb->lost_cnt);
/*
* if the interface goes down without any activity, a value
* of 0xFFFFFFFF will be continuously read, and the detection
* will be happened eventually.
*/
hb->last_uptime = uptime_s;
} else {
/* reset heart beat lost cnt */
hb->lost_cnt = 0;
}
/* next, check if heartbeat exceeds limit */
if (hb->lost_cnt > BCM_VK_HB_LOST_MAX) {
dev_err(&vk->pdev->dev, "Heartbeat Misses %d times, %d s!\n",
BCM_VK_HB_LOST_MAX,
BCM_VK_HB_LOST_MAX * BCM_VK_HB_TIMER_S);
bcm_vk_blk_drv_access(vk);
bcm_vk_set_host_alert(vk, ERR_LOG_HOST_HB_FAIL);
}
/* re-arm timer */
schedule_delayed_work(&hb->work, BCM_VK_HB_TIMER_VALUE);
}
void bcm_vk_hb_init(struct bcm_vk *vk)
{
struct bcm_vk_hb_ctrl *hb = &vk->hb_ctrl;
INIT_DELAYED_WORK(&hb->work, bcm_vk_hb_poll);
schedule_delayed_work(&hb->work, BCM_VK_HB_TIMER_VALUE);
}
void bcm_vk_hb_deinit(struct bcm_vk *vk)
{
struct bcm_vk_hb_ctrl *hb = &vk->hb_ctrl;
cancel_delayed_work_sync(&hb->work);
}
static void bcm_vk_msgid_bitmap_clear(struct bcm_vk *vk,
unsigned int start,
unsigned int nbits)
{
spin_lock(&vk->msg_id_lock);
bitmap_clear(vk->bmap, start, nbits);
spin_unlock(&vk->msg_id_lock);
}
/*
* allocate a ctx per file struct
*/
static struct bcm_vk_ctx *bcm_vk_get_ctx(struct bcm_vk *vk, const pid_t pid)
{
u32 i;
struct bcm_vk_ctx *ctx = NULL;
u32 hash_idx = hash_32(pid, VK_PID_HT_SHIFT_BIT);
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;
ctx = &vk->ctx[i];
break;
}
}
if (!ctx) {
dev_err(&vk->pdev->dev, "All context in use\n");
goto all_in_use_exit;
}
/* set the pid and insert it to hash table */
ctx->pid = pid;
ctx->hash_idx = hash_idx;
list_add_tail(&ctx->node, &vk->pid_ht[hash_idx].head);
/* increase kref */
kref_get(&vk->kref);
/* clear counter */
atomic_set(&ctx->pend_cnt, 0);
atomic_set(&ctx->dma_cnt, 0);
init_waitqueue_head(&ctx->rd_wq);
all_in_use_exit:
in_reset_exit:
spin_unlock(&vk->ctx_lock);
return ctx;
}
static u16 bcm_vk_get_msg_id(struct bcm_vk *vk)
{
u16 rc = VK_MSG_ID_OVERFLOW;
u16 test_bit_count = 0;
spin_lock(&vk->msg_id_lock);
while (test_bit_count < (VK_MSG_ID_BITMAP_SIZE - 1)) {
/*
* first time come in this loop, msg_id will be 0
* and the first one tested will be 1. We skip
* VK_SIMPLEX_MSG_ID (0) for one way host2vk
* communication
*/
vk->msg_id++;
if (vk->msg_id == VK_MSG_ID_BITMAP_SIZE)
vk->msg_id = 1;
if (test_bit(vk->msg_id, vk->bmap)) {
test_bit_count++;
continue;
}
rc = vk->msg_id;
bitmap_set(vk->bmap, vk->msg_id, 1);
break;
}
spin_unlock(&vk->msg_id_lock);
return rc;
}
static int bcm_vk_free_ctx(struct bcm_vk *vk, struct bcm_vk_ctx *ctx)
{
u32 idx;
u32 hash_idx;
pid_t pid;
struct bcm_vk_ctx *entry;
int count = 0;
if (!ctx) {
dev_err(&vk->pdev->dev, "NULL context detected\n");
return -EINVAL;
}
idx = ctx->idx;
pid = ctx->pid;
spin_lock(&vk->ctx_lock);
if (!vk->ctx[idx].in_use) {
dev_err(&vk->pdev->dev, "context[%d] not in use!\n", idx);
} else {
vk->ctx[idx].in_use = false;
vk->ctx[idx].miscdev = NULL;
/* Remove it from hash list and see if it is the last one. */
list_del(&ctx->node);
hash_idx = ctx->hash_idx;
list_for_each_entry(entry, &vk->pid_ht[hash_idx].head, node) {
if (entry->pid == pid)
count++;
}
}
spin_unlock(&vk->ctx_lock);
return count;
}
static void bcm_vk_free_wkent(struct device *dev, struct bcm_vk_wkent *entry)
{
int proc_cnt;
bcm_vk_sg_free(dev, entry->dma, VK_DMA_MAX_ADDRS, &proc_cnt);
if (proc_cnt)
atomic_dec(&entry->ctx->dma_cnt);
kfree(entry->to_h_msg);
kfree(entry);
}
static void bcm_vk_drain_all_pend(struct device *dev,
struct bcm_vk_msg_chan *chan,
struct bcm_vk_ctx *ctx)
{
u32 num;
struct bcm_vk_wkent *entry, *tmp;
struct bcm_vk *vk;
struct list_head del_q;
if (ctx)
vk = container_of(ctx->miscdev, struct bcm_vk, miscdev);
INIT_LIST_HEAD(&del_q);
spin_lock(&chan->pendq_lock);
for (num = 0; num < chan->q_nr; num++) {
list_for_each_entry_safe(entry, tmp, &chan->pendq[num], node) {
if ((!ctx) || (entry->ctx->idx == ctx->idx)) {
list_move_tail(&entry->node, &del_q);
}
}
}
spin_unlock(&chan->pendq_lock);
/* batch clean up */
num = 0;
list_for_each_entry_safe(entry, tmp, &del_q, node) {
list_del(&entry->node);
num++;
if (ctx) {
struct vk_msg_blk *msg;
int bit_set;
bool responded;
u32 msg_id;
/* if it is specific ctx, log for any stuck */
msg = entry->to_v_msg;
msg_id = get_msg_id(msg);
bit_set = test_bit(msg_id, vk->bmap);
responded = entry->to_h_msg ? true : false;
if (num <= batch_log)
dev_info(dev,
"Drained: fid %u size %u msg 0x%x(seq-%x) ctx 0x%x[fd-%d] args:[0x%x 0x%x] resp %s, bmap %d\n",
msg->function_id, msg->size,
msg_id, entry->seq_num,
msg->context_id, entry->ctx->idx,
msg->cmd, msg->arg,
responded ? "T" : "F", bit_set);
if (responded)
atomic_dec(&ctx->pend_cnt);
else if (bit_set)
bcm_vk_msgid_bitmap_clear(vk, msg_id, 1);
}
bcm_vk_free_wkent(dev, entry);
}
if (num && ctx)
dev_info(dev, "Total drained items %d [fd-%d]\n",
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
*/
int bcm_vk_sync_msgq(struct bcm_vk *vk, bool force_sync)
{
struct bcm_vk_msgq __iomem *msgq;
struct device *dev = &vk->pdev->dev;
u32 msgq_off;
u32 num_q;
struct bcm_vk_msg_chan *chan_list[] = {&vk->to_v_msg_chan,
&vk->to_h_msg_chan};
struct bcm_vk_msg_chan *chan;
int i, j;
int ret = 0;
/*
* If the driver is loaded at startup where vk OS is not up yet,
* the msgq-info may not be available until a later time. In
* this case, we skip and the sync function is supposed to be
* called again.
*/
if (!bcm_vk_msgq_marker_valid(vk)) {
dev_info(dev, "BAR1 msgq marker not initialized.\n");
return -EAGAIN;
}
msgq_off = vkread32(vk, BAR_1, VK_BAR1_MSGQ_CTRL_OFF);
/* each side is always half the total */
num_q = vkread32(vk, BAR_1, VK_BAR1_MSGQ_NR) / 2;
if (!num_q || (num_q > VK_MSGQ_PER_CHAN_MAX)) {
dev_err(dev,
"Advertised msgq %d error - max %d allowed\n",
num_q, VK_MSGQ_PER_CHAN_MAX);
return -EINVAL;
}
vk->to_v_msg_chan.q_nr = num_q;
vk->to_h_msg_chan.q_nr = num_q;
/* first msgq location */
msgq = vk->bar[BAR_1] + msgq_off;
/*
* if this function is called when it is already inited,
* something is wrong
*/
if (bcm_vk_drv_access_ok(vk) && !force_sync) {
dev_err(dev, "Msgq info already in sync\n");
return -EPERM;
}
for (i = 0; i < ARRAY_SIZE(chan_list); i++) {
chan = chan_list[i];
memset(chan->sync_qinfo, 0, sizeof(chan->sync_qinfo));
for (j = 0; j < num_q; j++) {
struct bcm_vk_sync_qinfo *qinfo;
u32 msgq_start;
u32 msgq_size;
u32 msgq_nxt;
u32 msgq_db_offset, q_db_offset;
chan->msgq[j] = msgq;
msgq_start = readl_relaxed(&msgq->start);
msgq_size = readl_relaxed(&msgq->size);
msgq_nxt = readl_relaxed(&msgq->nxt);
msgq_db_offset = readl_relaxed(&msgq->db_offset);
q_db_offset = (msgq_db_offset & ((1 << DB_SHIFT) - 1));
if (q_db_offset == (~msgq_db_offset >> DB_SHIFT))
msgq_db_offset = q_db_offset;
else
/* fall back to default */
msgq_db_offset = VK_BAR0_Q_DB_BASE(j);
dev_info(dev,
"MsgQ[%d] type %d num %d, @ 0x%x, db_offset 0x%x rd_idx %d wr_idx %d, size %d, nxt 0x%x\n",
j,
readw_relaxed(&msgq->type),
readw_relaxed(&msgq->num),
msgq_start,
msgq_db_offset,
readl_relaxed(&msgq->rd_idx),
readl_relaxed(&msgq->wr_idx),
msgq_size,
msgq_nxt);
qinfo = &chan->sync_qinfo[j];
/* formulate and record static info */
qinfo->q_start = vk->bar[BAR_1] + msgq_start;
qinfo->q_size = msgq_size;
/* set low threshold as 50% or 1/2 */
qinfo->q_low = qinfo->q_size >> 1;
qinfo->q_mask = qinfo->q_size - 1;
qinfo->q_db_offset = msgq_db_offset;
msgq++;
}
}
atomic_set(&vk->msgq_inited, 1);
return ret;
}
static int bcm_vk_msg_chan_init(struct bcm_vk_msg_chan *chan)
{
u32 i;
mutex_init(&chan->msgq_mutex);
spin_lock_init(&chan->pendq_lock);
for (i = 0; i < VK_MSGQ_MAX_NR; i++)
INIT_LIST_HEAD(&chan->pendq[i]);
return 0;
}
static void bcm_vk_append_pendq(struct bcm_vk_msg_chan *chan, u16 q_num,
struct bcm_vk_wkent *entry)
{
struct bcm_vk_ctx *ctx;
spin_lock(&chan->pendq_lock);
list_add_tail(&entry->node, &chan->pendq[q_num]);
if (entry->to_h_msg) {
ctx = entry->ctx;
atomic_inc(&ctx->pend_cnt);
wake_up_interruptible(&ctx->rd_wq);
}
spin_unlock(&chan->pendq_lock);
}
static u32 bcm_vk_append_ib_sgl(struct bcm_vk *vk,
struct bcm_vk_wkent *entry,
struct _vk_data *data,
unsigned int num_planes)
{
unsigned int i;
unsigned int item_cnt = 0;
struct device *dev = &vk->pdev->dev;
struct bcm_vk_msg_chan *chan = &vk->to_v_msg_chan;
struct vk_msg_blk *msg = &entry->to_v_msg[0];
struct bcm_vk_msgq __iomem *msgq;
struct bcm_vk_sync_qinfo *qinfo;
u32 ib_sgl_size = 0;
u8 *buf = (u8 *)&entry->to_v_msg[entry->to_v_blks];
u32 avail;
u32 q_num;
/* check if high watermark is hit, and if so, skip */
q_num = get_q_num(msg);
msgq = chan->msgq[q_num];
qinfo = &chan->sync_qinfo[q_num];
avail = msgq_avail_space(msgq, qinfo);
if (avail < qinfo->q_low) {
dev_dbg(dev, "Skip inserting inband SGL, [0x%x/0x%x]\n",
avail, qinfo->q_size);
return 0;
}
for (i = 0; i < num_planes; i++) {
if (data[i].address &&
(ib_sgl_size + data[i].size) <= vk->ib_sgl_size) {
item_cnt++;
memcpy(buf, entry->dma[i].sglist, data[i].size);
ib_sgl_size += data[i].size;
buf += data[i].size;
}
}
dev_dbg(dev, "Num %u sgl items appended, size 0x%x, room 0x%x\n",
item_cnt, ib_sgl_size, vk->ib_sgl_size);
/* round up size */
ib_sgl_size = (ib_sgl_size + VK_MSGQ_BLK_SIZE - 1)
>> VK_MSGQ_BLK_SZ_SHIFT;
return ib_sgl_size;
}
void bcm_to_v_q_doorbell(struct bcm_vk *vk, u32 q_num, u32 db_val)
{
struct bcm_vk_msg_chan *chan = &vk->to_v_msg_chan;
struct bcm_vk_sync_qinfo *qinfo = &chan->sync_qinfo[q_num];
vkwrite32(vk, db_val, BAR_0, qinfo->q_db_offset);
}
static int bcm_to_v_msg_enqueue(struct bcm_vk *vk, struct bcm_vk_wkent *entry)
{
static u32 seq_num;
struct bcm_vk_msg_chan *chan = &vk->to_v_msg_chan;
struct device *dev = &vk->pdev->dev;
struct vk_msg_blk *src = &entry->to_v_msg[0];
struct vk_msg_blk __iomem *dst;
struct bcm_vk_msgq __iomem *msgq;
struct bcm_vk_sync_qinfo *qinfo;
u32 q_num = get_q_num(src);
u32 wr_idx; /* local copy */
u32 i;
u32 avail;
u32 retry;
if (entry->to_v_blks != src->size + 1) {
dev_err(dev, "number of blks %d not matching %d MsgId[0x%x]: func %d ctx 0x%x\n",
entry->to_v_blks,
src->size + 1,
get_msg_id(src),
src->function_id,
src->context_id);
return -EMSGSIZE;
}
msgq = chan->msgq[q_num];
qinfo = &chan->sync_qinfo[q_num];
mutex_lock(&chan->msgq_mutex);
avail = msgq_avail_space(msgq, qinfo);
/* if not enough space, return EAGAIN and let app handles it */
retry = 0;
while ((avail < entry->to_v_blks) &&
(retry++ < BCM_VK_H2VK_ENQ_RETRY)) {
mutex_unlock(&chan->msgq_mutex);
msleep(BCM_VK_H2VK_ENQ_RETRY_DELAY_MS);
mutex_lock(&chan->msgq_mutex);
avail = msgq_avail_space(msgq, qinfo);
}
if (retry > BCM_VK_H2VK_ENQ_RETRY) {
mutex_unlock(&chan->msgq_mutex);
return -EAGAIN;
}
/* at this point, mutex is taken and there is enough space */
entry->seq_num = seq_num++; /* update debug seq number */
wr_idx = readl_relaxed(&msgq->wr_idx);
if (wr_idx >= qinfo->q_size) {
dev_crit(dev, "Invalid wr_idx 0x%x => max 0x%x!",
wr_idx, qinfo->q_size);
bcm_vk_blk_drv_access(vk);
bcm_vk_set_host_alert(vk, ERR_LOG_HOST_PCIE_DWN);
goto idx_err;
}
dst = msgq_blk_addr(qinfo, wr_idx);
for (i = 0; i < entry->to_v_blks; i++) {
memcpy_toio(dst, src, sizeof(*dst));
src++;
wr_idx = msgq_inc(qinfo, wr_idx, 1);
dst = msgq_blk_addr(qinfo, wr_idx);
}
/* flush the write pointer */
writel(wr_idx, &msgq->wr_idx);
/* log new info for debugging */
dev_dbg(dev,
"MsgQ[%d] [Rd Wr] = [%d %d] blks inserted %d - Q = [u-%d a-%d]/%d\n",
readl_relaxed(&msgq->num),
readl_relaxed(&msgq->rd_idx),
wr_idx,
entry->to_v_blks,
msgq_occupied(msgq, qinfo),
msgq_avail_space(msgq, qinfo),
readl_relaxed(&msgq->size));
/*
* press door bell based on queue number. 1 is added to the wr_idx
* to avoid the value of 0 appearing on the VK side to distinguish
* from initial value.
*/
bcm_to_v_q_doorbell(vk, q_num, wr_idx + 1);
idx_err:
mutex_unlock(&chan->msgq_mutex);
return 0;
}
int bcm_vk_send_shutdown_msg(struct bcm_vk *vk, u32 shut_type,
const pid_t pid, const u32 q_num)
{
int rc = 0;
struct bcm_vk_wkent *entry;
struct device *dev = &vk->pdev->dev;
/*
* check if the marker is still good. Sometimes, the PCIe interface may
* have gone done, and if so and we ship down thing based on broken
* values, kernel may panic.
*/
if (!bcm_vk_msgq_marker_valid(vk)) {
dev_info(dev, "PCIe comm chan - invalid marker (0x%x)!\n",
vkread32(vk, BAR_1, VK_BAR1_MSGQ_DEF_RDY));
return -EINVAL;
}
entry = kzalloc(struct_size(entry, to_v_msg, 1), GFP_KERNEL);
if (!entry)
return -ENOMEM;
entry->to_v_blks = 1; /* always 1 block */
/* fill up necessary data */
entry->to_v_msg[0].function_id = VK_FID_SHUTDOWN;
set_q_num(&entry->to_v_msg[0], q_num);
set_msg_id(&entry->to_v_msg[0], VK_SIMPLEX_MSG_ID);
entry->to_v_msg[0].cmd = shut_type;
entry->to_v_msg[0].arg = pid;
rc = bcm_to_v_msg_enqueue(vk, entry);
if (rc)
dev_err(dev,
"Sending shutdown message to q %d for pid %d fails.\n",
get_q_num(&entry->to_v_msg[0]), pid);
kfree(entry);
return rc;
}
static int bcm_vk_handle_last_sess(struct bcm_vk *vk, const pid_t pid,
const u32 q_num)
{
int rc = 0;
struct device *dev = &vk->pdev->dev;
/*
* 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 (vk->reset_pid == pid)
vk->reset_pid = 0;
return -EPERM;
}
dev_dbg(dev, "No more sessions, shut down pid %d\n", pid);
/* 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;
}
static struct bcm_vk_wkent *bcm_vk_dequeue_pending(struct bcm_vk *vk,
struct bcm_vk_msg_chan *chan,
u16 q_num,
u16 msg_id)
{
struct bcm_vk_wkent *entry = NULL, *iter;
spin_lock(&chan->pendq_lock);
list_for_each_entry(iter, &chan->pendq[q_num], node) {
if (get_msg_id(&iter->to_v_msg[0]) == msg_id) {
list_del(&iter->node);
entry = iter;
bcm_vk_msgid_bitmap_clear(vk, msg_id, 1);
break;
}
}
spin_unlock(&chan->pendq_lock);
return entry;
}
s32 bcm_to_h_msg_dequeue(struct bcm_vk *vk)
{
struct device *dev = &vk->pdev->dev;
struct bcm_vk_msg_chan *chan = &vk->to_h_msg_chan;
struct vk_msg_blk *data;
struct vk_msg_blk __iomem *src;
struct vk_msg_blk *dst;
struct bcm_vk_msgq __iomem *msgq;
struct bcm_vk_sync_qinfo *qinfo;
struct bcm_vk_wkent *entry;
u32 rd_idx, wr_idx;
u32 q_num, msg_id, j;
u32 num_blks;
s32 total = 0;
int cnt = 0;
int msg_processed = 0;
int max_msg_to_process;
bool exit_loop;
/*
* drain all the messages from the queues, and find its pending
* entry in the to_v queue, based on msg_id & q_num, and move the
* entry to the to_h pending queue, waiting for user space
* program to extract
*/
mutex_lock(&chan->msgq_mutex);
for (q_num = 0; q_num < chan->q_nr; q_num++) {
msgq = chan->msgq[q_num];
qinfo = &chan->sync_qinfo[q_num];
max_msg_to_process = BCM_VK_MSG_PROC_MAX_LOOP * qinfo->q_size;
rd_idx = readl_relaxed(&msgq->rd_idx);
wr_idx = readl_relaxed(&msgq->wr_idx);
msg_processed = 0;
exit_loop = false;
while ((rd_idx != wr_idx) && !exit_loop) {
u8 src_size;
/*
* Make a local copy and get pointer to src blk
* The rd_idx is masked before getting the pointer to
* avoid out of bound access in case the interface goes
* down. It will end up pointing to the last block in
* the buffer, but subsequent src->size check would be
* able to catch this.
*/
src = msgq_blk_addr(qinfo, rd_idx & qinfo->q_mask);
src_size = readb(&src->size);
if ((rd_idx >= qinfo->q_size) ||
(src_size > (qinfo->q_size - 1))) {
dev_crit(dev,
"Invalid rd_idx 0x%x or size 0x%x => max 0x%x!",
rd_idx, src_size, qinfo->q_size);
bcm_vk_blk_drv_access(vk);
bcm_vk_set_host_alert(vk,
ERR_LOG_HOST_PCIE_DWN);
goto idx_err;
}
num_blks = src_size + 1;
data = kzalloc(num_blks * VK_MSGQ_BLK_SIZE, GFP_KERNEL);
if (data) {
/* copy messages and linearize it */
dst = data;
for (j = 0; j < num_blks; j++) {
memcpy_fromio(dst, src, sizeof(*dst));
dst++;
rd_idx = msgq_inc(qinfo, rd_idx, 1);
src = msgq_blk_addr(qinfo, rd_idx);
}
total++;
} else {
/*
* if we could not allocate memory in kernel,
* that is fatal.
*/
dev_crit(dev, "Kernel mem allocation failure.\n");
total = -ENOMEM;
goto idx_err;
}
/* flush rd pointer after a message is dequeued */
writel(rd_idx, &msgq->rd_idx);
/* log new info for debugging */
dev_dbg(dev,
"MsgQ[%d] [Rd Wr] = [%d %d] blks extracted %d - Q = [u-%d a-%d]/%d\n",
readl_relaxed(&msgq->num),
rd_idx,
wr_idx,
num_blks,
msgq_occupied(msgq, qinfo),
msgq_avail_space(msgq, qinfo),
readl_relaxed(&msgq->size));
/*
* No need to search if it is an autonomous one-way
* message from driver, as these messages do not bear
* a to_v pending item. Currently, only the shutdown
* message falls into this category.
*/
if (data->function_id == VK_FID_SHUTDOWN) {
kfree(data);
continue;
}
msg_id = get_msg_id(data);
/* lookup original message in to_v direction */
entry = bcm_vk_dequeue_pending(vk,
&vk->to_v_msg_chan,
q_num,
msg_id);
/*
* if there is message to does not have prior send,
* this is the location to add here
*/
if (entry) {
entry->to_h_blks = num_blks;
entry->to_h_msg = data;
bcm_vk_append_pendq(&vk->to_h_msg_chan,
q_num, entry);
} else {
if (cnt++ < batch_log)
dev_info(dev,
"Could not find MsgId[0x%x] for resp func %d bmap %d\n",
msg_id, data->function_id,
test_bit(msg_id, vk->bmap));
kfree(data);
}
/* Fetch wr_idx to handle more back-to-back events */
wr_idx = readl(&msgq->wr_idx);
/*
* cap the max so that even we try to handle more back-to-back events,
* so that it won't hold CPU too long or in case rd/wr idexes are
* corrupted which triggers infinite looping.
*/
if (++msg_processed >= max_msg_to_process) {
dev_warn(dev, "Q[%d] Per loop processing exceeds %d\n",
q_num, max_msg_to_process);
exit_loop = true;
}
}
}
idx_err:
mutex_unlock(&chan->msgq_mutex);
dev_dbg(dev, "total %d drained from queues\n", total);
return total;
}
/*
* init routine for all required data structures
*/
static int bcm_vk_data_init(struct bcm_vk *vk)
{
int i;
spin_lock_init(&vk->ctx_lock);
for (i = 0; i < ARRAY_SIZE(vk->ctx); i++) {
vk->ctx[i].in_use = false;
vk->ctx[i].idx = i; /* self identity */
vk->ctx[i].miscdev = NULL;
}
spin_lock_init(&vk->msg_id_lock);
spin_lock_init(&vk->host_alert_lock);
vk->msg_id = 0;
/* initialize hash table */
for (i = 0; i < VK_PID_HT_SZ; i++)
INIT_LIST_HEAD(&vk->pid_ht[i].head);
return 0;
}
irqreturn_t bcm_vk_msgq_irqhandler(int irq, void *dev_id)
{
struct bcm_vk *vk = dev_id;
if (!bcm_vk_drv_access_ok(vk)) {
dev_err(&vk->pdev->dev,
"Interrupt %d received when msgq not inited\n", irq);
goto skip_schedule_work;
}
queue_work(vk->wq_thread, &vk->wq_work);
skip_schedule_work:
return IRQ_HANDLED;
}
int bcm_vk_open(struct inode *inode, struct file *p_file)
{
struct bcm_vk_ctx *ctx;
struct miscdevice *miscdev = (struct miscdevice *)p_file->private_data;
struct bcm_vk *vk = container_of(miscdev, struct bcm_vk, miscdev);
struct device *dev = &vk->pdev->dev;
int rc = 0;
/* get a context and set it up for file */
ctx = bcm_vk_get_ctx(vk, task_tgid_nr(current));
if (!ctx) {
dev_err(dev, "Error allocating context\n");
rc = -ENOMEM;
} else {
/*
* set up context and replace private data with context for
* other methods to use. Reason for the context is because
* it is allowed for multiple sessions to open the sysfs, and
* for each file open, when upper layer query the response,
* only those that are tied to a specific open should be
* returned. The context->idx will be used for such binding
*/
ctx->miscdev = miscdev;
p_file->private_data = ctx;
dev_dbg(dev, "ctx_returned with idx %d, pid %d\n",
ctx->idx, ctx->pid);
}
return rc;
}
ssize_t bcm_vk_read(struct file *p_file,
char __user *buf,
size_t count,
loff_t *f_pos)
{
ssize_t rc = -ENOMSG;
struct bcm_vk_ctx *ctx = p_file->private_data;
struct bcm_vk *vk = container_of(ctx->miscdev, struct bcm_vk,
miscdev);
struct device *dev = &vk->pdev->dev;
struct bcm_vk_msg_chan *chan = &vk->to_h_msg_chan;
struct bcm_vk_wkent *entry = NULL, *iter;
u32 q_num;
u32 rsp_length;
if (!bcm_vk_drv_access_ok(vk))
return -EPERM;
dev_dbg(dev, "Buf count %zu\n", count);
/*
* search through the pendq on the to_h chan, and return only those
* that belongs to the same context. Search is always from the high to
* the low priority queues
*/
spin_lock(&chan->pendq_lock);
for (q_num = 0; q_num < chan->q_nr; q_num++) {
list_for_each_entry(iter, &chan->pendq[q_num], node) {
if (iter->ctx->idx == ctx->idx) {
if (count >=
(iter->to_h_blks * VK_MSGQ_BLK_SIZE)) {
list_del(&iter->node);
atomic_dec(&ctx->pend_cnt);
entry = iter;
} else {
/* buffer not big enough */
rc = -EMSGSIZE;
}
goto read_loop_exit;
}
}
}
read_loop_exit:
spin_unlock(&chan->pendq_lock);
if (entry) {
/* retrieve the passed down msg_id */
set_msg_id(&entry->to_h_msg[0], entry->usr_msg_id);
rsp_length = entry->to_h_blks * VK_MSGQ_BLK_SIZE;
if (copy_to_user(buf, entry->to_h_msg, rsp_length) == 0)
rc = rsp_length;
bcm_vk_free_wkent(dev, entry);
} else if (rc == -EMSGSIZE) {
struct vk_msg_blk tmp_msg = entry->to_h_msg[0];
/*
* in this case, return just the first block, so
* that app knows what size it is looking for.
*/
set_msg_id(&tmp_msg, entry->usr_msg_id);
tmp_msg.size = entry->to_h_blks - 1;
if (copy_to_user(buf, &tmp_msg, VK_MSGQ_BLK_SIZE) != 0) {
dev_err(dev, "Error return 1st block in -EMSGSIZE\n");
rc = -EFAULT;
}
}
return rc;
}
ssize_t bcm_vk_write(struct file *p_file,
const char __user *buf,
size_t count,
loff_t *f_pos)
{
ssize_t rc;
struct bcm_vk_ctx *ctx = p_file->private_data;
struct bcm_vk *vk = container_of(ctx->miscdev, struct bcm_vk,
miscdev);
struct bcm_vk_msgq __iomem *msgq;
struct device *dev = &vk->pdev->dev;
struct bcm_vk_wkent *entry;
u32 sgl_extra_blks;
u32 q_num;
u32 msg_size;
u32 msgq_size;
if (!bcm_vk_drv_access_ok(vk))
return -EPERM;
dev_dbg(dev, "Msg count %zu\n", count);
/* first, do sanity check where count should be multiple of basic blk */
if (count & (VK_MSGQ_BLK_SIZE - 1)) {
dev_err(dev, "Failure with size %zu not multiple of %zu\n",
count, VK_MSGQ_BLK_SIZE);
rc = -EINVAL;
goto write_err;
}
/* allocate the work entry + buffer for size count and inband sgl */
entry = kzalloc(sizeof(*entry) + count + vk->ib_sgl_size,
GFP_KERNEL);
if (!entry) {
rc = -ENOMEM;
goto write_err;
}
/* now copy msg from user space, and then formulate the work entry */
if (copy_from_user(&entry->to_v_msg[0], buf, count)) {
rc = -EFAULT;
goto write_free_ent;
}
entry->to_v_blks = count >> VK_MSGQ_BLK_SZ_SHIFT;
entry->ctx = ctx;
/* do a check on the blk size which could not exceed queue space */
q_num = get_q_num(&entry->to_v_msg[0]);
msgq = vk->to_v_msg_chan.msgq[q_num];
msgq_size = readl_relaxed(&msgq->size);
if (entry->to_v_blks + (vk->ib_sgl_size >> VK_MSGQ_BLK_SZ_SHIFT)
> (msgq_size - 1)) {
dev_err(dev, "Blk size %d exceed max queue size allowed %d\n",
entry->to_v_blks, msgq_size - 1);
rc = -EINVAL;
goto write_free_ent;
}
/* Use internal message id */
entry->usr_msg_id = get_msg_id(&entry->to_v_msg[0]);
rc = bcm_vk_get_msg_id(vk);
if (rc == VK_MSG_ID_OVERFLOW) {
dev_err(dev, "msg_id overflow\n");
rc = -EOVERFLOW;
goto write_free_ent;
}
set_msg_id(&entry->to_v_msg[0], rc);
ctx->q_num = q_num;
dev_dbg(dev,
"[Q-%d]Message ctx id %d, usr_msg_id 0x%x sent msg_id 0x%x\n",
ctx->q_num, ctx->idx, entry->usr_msg_id,
get_msg_id(&entry->to_v_msg[0]));
if (entry->to_v_msg[0].function_id == VK_FID_TRANS_BUF) {
/* Convert any pointers to sg list */
unsigned int num_planes;
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;
else
dir = DMA_TO_DEVICE;
/* Calculate vk_data location */
/* Go to end of the message */
msg_size = entry->to_v_msg[0].size;
if (msg_size > entry->to_v_blks) {
rc = -EMSGSIZE;
goto write_free_msgid;
}
data = (struct _vk_data *)&entry->to_v_msg[msg_size + 1];
/* Now back up to the start of the pointers */
data -= num_planes;
/* Convert user addresses to DMA SG List */
rc = bcm_vk_sg_alloc(dev, entry->dma, dir, data, num_planes);
if (rc)
goto write_free_msgid;
atomic_inc(&ctx->dma_cnt);
/* try to embed inband sgl */
sgl_extra_blks = bcm_vk_append_ib_sgl(vk, entry, data,
num_planes);
entry->to_v_blks += sgl_extra_blks;
entry->to_v_msg[0].size += sgl_extra_blks;
} else if (entry->to_v_msg[0].function_id == VK_FID_INIT &&
entry->to_v_msg[0].context_id == VK_NEW_CTX) {
/*
* Init happens in 2 stages, only the first stage contains the
* pid that needs translating.
*/
pid_t org_pid, pid;
/*
* translate the pid into the unique host space as user
* may run sessions inside containers or process
* namespaces.
*/
#define VK_MSG_PID_MASK 0xffffff00
#define VK_MSG_PID_SH 8
org_pid = (entry->to_v_msg[0].arg & VK_MSG_PID_MASK)
>> VK_MSG_PID_SH;
pid = task_tgid_nr(current);
entry->to_v_msg[0].arg =
(entry->to_v_msg[0].arg & ~VK_MSG_PID_MASK) |
(pid << VK_MSG_PID_SH);
if (org_pid != pid)
dev_dbg(dev, "In PID 0x%x(%d), converted PID 0x%x(%d)\n",
org_pid, org_pid, pid, pid);
}
/*
* store work entry to pending queue until a response is received.
* This needs to be done before enqueuing the message
*/
bcm_vk_append_pendq(&vk->to_v_msg_chan, q_num, entry);
rc = bcm_to_v_msg_enqueue(vk, entry);
if (rc) {
dev_err(dev, "Fail to enqueue msg to to_v queue\n");
/* remove message from pending list */
entry = bcm_vk_dequeue_pending
(vk,
&vk->to_v_msg_chan,
q_num,
get_msg_id(&entry->to_v_msg[0]));
goto write_free_ent;
}
return count;
write_free_msgid:
bcm_vk_msgid_bitmap_clear(vk, get_msg_id(&entry->to_v_msg[0]), 1);
write_free_ent:
kfree(entry);
write_err:
return rc;
}
__poll_t bcm_vk_poll(struct file *p_file, struct poll_table_struct *wait)
{
__poll_t ret = 0;
int cnt;
struct bcm_vk_ctx *ctx = p_file->private_data;
struct bcm_vk *vk = container_of(ctx->miscdev, struct bcm_vk, miscdev);
struct device *dev = &vk->pdev->dev;
poll_wait(p_file, &ctx->rd_wq, wait);
cnt = atomic_read(&ctx->pend_cnt);
if (cnt) {
ret = (__force __poll_t)(POLLIN | POLLRDNORM);
if (cnt < 0) {
dev_err(dev, "Error cnt %d, setting back to 0", cnt);
atomic_set(&ctx->pend_cnt, 0);
}
}
return ret;
}
int bcm_vk_release(struct inode *inode, struct file *p_file)
{
int ret;
struct bcm_vk_ctx *ctx = p_file->private_data;
struct bcm_vk *vk = container_of(ctx->miscdev, struct bcm_vk, miscdev);
struct device *dev = &vk->pdev->dev;
pid_t pid = ctx->pid;
int dma_cnt;
unsigned long timeout, start_time;
/*
* if there are outstanding DMA transactions, need to delay long enough
* to ensure that the card side would have stopped touching the host buffer
* and its SGL list. A race condition could happen if the host app is killed
* abruptly, eg kill -9, while some DMA transfer orders are still inflight.
* Nothing could be done except for a delay as host side is running in a
* completely async fashion.
*/
start_time = jiffies;
timeout = start_time + msecs_to_jiffies(BCM_VK_DMA_DRAIN_MAX_MS);
do {
if (time_after(jiffies, timeout)) {
dev_warn(dev, "%d dma still pending for [fd-%d] pid %d\n",
dma_cnt, ctx->idx, pid);
break;
}
dma_cnt = atomic_read(&ctx->dma_cnt);
cpu_relax();
cond_resched();
} while (dma_cnt);
dev_dbg(dev, "Draining for [fd-%d] pid %d - delay %d ms\n",
ctx->idx, pid, jiffies_to_msecs(jiffies - start_time));
bcm_vk_drain_all_pend(&vk->pdev->dev, &vk->to_v_msg_chan, ctx);
bcm_vk_drain_all_pend(&vk->pdev->dev, &vk->to_h_msg_chan, ctx);
ret = bcm_vk_free_ctx(vk, ctx);
if (ret == 0)
ret = bcm_vk_handle_last_sess(vk, pid, ctx->q_num);
else
ret = 0;
kref_put(&vk->kref, bcm_vk_release_data);
return ret;
}
int bcm_vk_msg_init(struct bcm_vk *vk)
{
struct device *dev = &vk->pdev->dev;
int ret;
if (bcm_vk_data_init(vk)) {
dev_err(dev, "Error initializing internal data structures\n");
return -EINVAL;
}
if (bcm_vk_msg_chan_init(&vk->to_v_msg_chan) ||
bcm_vk_msg_chan_init(&vk->to_h_msg_chan)) {
dev_err(dev, "Error initializing communication channel\n");
return -EIO;
}
/* read msgq info if ready */
ret = bcm_vk_sync_msgq(vk, false);
if (ret && (ret != -EAGAIN)) {
dev_err(dev, "Error reading comm msg Q info\n");
return -EIO;
}
return 0;
}
void bcm_vk_msg_remove(struct bcm_vk *vk)
{
bcm_vk_blk_drv_access(vk);
/* drain all pending items */
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);
}
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