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Subject[RFC PATCH v3] Bluetooth: hci_qca: Collect controller memory dump during SSR
Date
We will collect the ramdump of BT controller when hardware error event
received before rebooting the HCI layer. Before restarting a subsystem
or a process running on a subsystem, it is often required to request
either a subsystem or a process to perform proper cache dump and
software failure reason into a memory buffer which application
processor can retrieve afterwards. SW developers can often provide
initial investigation by looking into that debugging information.

Signed-off-by: Balakrishna Godavarthi <bgodavar@codeaurora.org>
---
changes v3:
* used wakeup helper instead of polling while collecting dump.
* directly coping the crash command to the skb instead of local buffer.
* update review comments.
---
drivers/bluetooth/hci_qca.c | 291 +++++++++++++++++++++++++++++++++++-
1 file changed, 287 insertions(+), 4 deletions(-)

diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
index 237aea34b69f..2b9bcf811776 100644
--- a/drivers/bluetooth/hci_qca.c
+++ b/drivers/bluetooth/hci_qca.c
@@ -32,6 +32,7 @@
#include <linux/clk.h>
#include <linux/debugfs.h>
#include <linux/delay.h>
+#include <linux/devcoredump.h>
#include <linux/device.h>
#include <linux/gpio/consumer.h>
#include <linux/mod_devicetable.h>
@@ -56,10 +57,12 @@

/* Controller states */
#define STATE_IN_BAND_SLEEP_ENABLED 1
+#define STATE_MEMDUMP_COLLECTION 2

#define IBS_WAKE_RETRANS_TIMEOUT_MS 100
#define IBS_TX_IDLE_TIMEOUT_MS 2000
#define CMD_TRANS_TIMEOUT_MS 100
+#define MEMDUMP_COLLECTION_TIMEOUT_MS 8000

/* susclk rate */
#define SUSCLK_RATE_32KHZ 32768
@@ -67,6 +70,13 @@
/* Controller debug log header */
#define QCA_DEBUG_HANDLE 0x2EDC

+/* Controller dump header */
+#define QCA_SSR_DUMP_HANDLE 0x0108
+#define QCA_DUMP_PACKET_SIZE 255
+#define QCA_LAST_SEQUENCE_NUM 0xFFFF
+#define QCA_CRASHBYTE_PACKET_LEN 1100
+#define QCA_MEMDUMP_BYTE 0xFB
+
/* HCI_IBS transmit side sleep protocol states */
enum tx_ibs_states {
HCI_IBS_TX_ASLEEP,
@@ -89,12 +99,41 @@ enum hci_ibs_clock_state_vote {
HCI_IBS_RX_VOTE_CLOCK_OFF,
};

+/* Controller memory dump states */
+enum qca_memdump_states {
+ QCA_MEMDUMP_IDLE,
+ QCA_MEMDUMP_COLLECTING,
+ QCA_MEMDUMP_COLLECTED,
+ QCA_MEMDUMP_TIMEOUT,
+};
+
+struct qca_memdump_data {
+ char *memdump_buf_head;
+ char *memdump_buf_tail;
+ u32 current_seq_no;
+ u32 received_dump;
+};
+
+struct qca_memdump_event_hdr {
+ __u8 evt;
+ __u8 plen;
+ __u16 opcode;
+ __u16 seq_no;
+ __u8 reserved;
+} __packed;
+
+
+struct qca_dump_size {
+ u32 dump_size;
+} __packed;
+
struct qca_data {
struct hci_uart *hu;
struct sk_buff *rx_skb;
struct sk_buff_head txq;
- struct sk_buff_head tx_wait_q; /* HCI_IBS wait queue */
- spinlock_t hci_ibs_lock; /* HCI_IBS state lock */
+ struct sk_buff_head tx_wait_q; /* HCI_IBS wait queue */
+ struct sk_buff_head rx_memdump_q; /* Memdump wait queue */
+ spinlock_t hci_ibs_lock; /* HCI_IBS state lock */
u8 tx_ibs_state; /* HCI_IBS transmit side power state*/
u8 rx_ibs_state; /* HCI_IBS receive side power state */
bool tx_vote; /* Clock must be on for TX */
@@ -103,12 +142,17 @@ struct qca_data {
u32 tx_idle_delay;
struct timer_list wake_retrans_timer;
u32 wake_retrans;
+ struct timer_list memdump_timer;
+ u32 memdump_delay;
struct workqueue_struct *workqueue;
struct work_struct ws_awake_rx;
struct work_struct ws_awake_device;
struct work_struct ws_rx_vote_off;
struct work_struct ws_tx_vote_off;
+ struct work_struct ctrl_memdump_evt;
+ struct qca_memdump_data *qca_memdump;
unsigned long flags;
+ enum qca_memdump_states memdump_state;

/* For debugging purpose */
u64 ibs_sent_wacks;
@@ -173,6 +217,7 @@ struct qca_serdev {
static int qca_power_setup(struct hci_uart *hu, bool on);
static void qca_power_shutdown(struct hci_uart *hu);
static int qca_power_off(struct hci_dev *hdev);
+static void qca_controller_memdump(struct work_struct *work);

static void __serial_clock_on(struct tty_struct *tty)
{
@@ -446,6 +491,21 @@ static void hci_ibs_wake_retrans_timeout(struct timer_list *t)
hci_uart_tx_wakeup(hu);
}

+static void hci_memdump_timeout(struct timer_list *t)
+{
+ struct qca_data *qca = from_timer(qca, t, tx_idle_timer);
+ struct hci_uart *hu = qca->hu;
+ struct qca_memdump_data *qca_memdump = qca->qca_memdump;
+ char *memdump_buf = qca_memdump->memdump_buf_tail;
+
+ bt_dev_err(hu->hdev, "clearing allocated memory due to memdump timeout");
+ kfree(memdump_buf);
+ kfree(qca_memdump);
+ qca->memdump_state = QCA_MEMDUMP_TIMEOUT;
+ del_timer(&qca->memdump_timer);
+ cancel_work_sync(&qca->ctrl_memdump_evt);
+}
+
/* Initialize protocol */
static int qca_open(struct hci_uart *hu)
{
@@ -461,6 +521,7 @@ static int qca_open(struct hci_uart *hu)

skb_queue_head_init(&qca->txq);
skb_queue_head_init(&qca->tx_wait_q);
+ skb_queue_head_init(&qca->rx_memdump_q);
spin_lock_init(&qca->hci_ibs_lock);
qca->workqueue = alloc_ordered_workqueue("qca_wq", 0);
if (!qca->workqueue) {
@@ -473,6 +534,7 @@ static int qca_open(struct hci_uart *hu)
INIT_WORK(&qca->ws_awake_device, qca_wq_awake_device);
INIT_WORK(&qca->ws_rx_vote_off, qca_wq_serial_rx_clock_vote_off);
INIT_WORK(&qca->ws_tx_vote_off, qca_wq_serial_tx_clock_vote_off);
+ INIT_WORK(&qca->ctrl_memdump_evt, qca_controller_memdump);

qca->hu = hu;

@@ -500,7 +562,7 @@ static int qca_open(struct hci_uart *hu)
qca->tx_votes_off = 0;
qca->rx_votes_on = 0;
qca->rx_votes_off = 0;
-
+ qca->memdump_state = QCA_MEMDUMP_IDLE;
hu->priv = qca;

if (hu->serdev) {
@@ -528,6 +590,9 @@ static int qca_open(struct hci_uart *hu)
timer_setup(&qca->tx_idle_timer, hci_ibs_tx_idle_timeout, 0);
qca->tx_idle_delay = IBS_TX_IDLE_TIMEOUT_MS;

+ timer_setup(&qca->memdump_timer, hci_memdump_timeout, 0);
+ qca->memdump_delay = MEMDUMP_COLLECTION_TIMEOUT_MS;
+
BT_DBG("HCI_UART_QCA open, tx_idle_delay=%u, wake_retrans=%u",
qca->tx_idle_delay, qca->wake_retrans);

@@ -605,8 +670,10 @@ static int qca_close(struct hci_uart *hu)

skb_queue_purge(&qca->tx_wait_q);
skb_queue_purge(&qca->txq);
+ skb_queue_purge(&qca->rx_memdump_q);
del_timer(&qca->tx_idle_timer);
del_timer(&qca->wake_retrans_timer);
+ del_timer(&qca->memdump_timer);
destroy_workqueue(qca->workqueue);
qca->hu = NULL;

@@ -867,6 +934,141 @@ static int qca_recv_acl_data(struct hci_dev *hdev, struct sk_buff *skb)
return hci_recv_frame(hdev, skb);
}

+static void qca_controller_memdump(struct work_struct *work)
+{
+ struct qca_data *qca = container_of(work, struct qca_data,
+ ctrl_memdump_evt);
+ struct hci_uart *hu = qca->hu;
+ struct sk_buff *skb;
+ struct qca_memdump_event_hdr *cmd_hdr;
+ struct qca_memdump_data *qca_memdump = qca->qca_memdump;
+ struct qca_dump_size *dump;
+ char *memdump_buf;
+ char nullBuff[QCA_DUMP_PACKET_SIZE] = { 0 };
+ u16 opcode, seq_no;
+ u32 dump_size;
+
+ while ((skb = skb_dequeue(&qca->rx_memdump_q))) {
+
+ if (!qca_memdump) {
+ qca_memdump = kzalloc(sizeof(struct qca_memdump_data),
+ GFP_ATOMIC);
+ if (!qca_memdump)
+ return;
+
+ qca->qca_memdump = qca_memdump;
+ }
+
+ qca->memdump_state = QCA_MEMDUMP_COLLECTING;
+ cmd_hdr = (void *) skb->data;
+ opcode = __le16_to_cpu(cmd_hdr->opcode);
+ seq_no = __le16_to_cpu(cmd_hdr->seq_no);
+ skb_pull(skb, sizeof(struct qca_memdump_event_hdr));
+
+ if (!seq_no) {
+
+ /* This is the first frame of memdump packet from
+ * the controller, Disable IBS to recevie dump
+ * with out any interruption, ideally time required for
+ * the controller to send the dump is 8 seconds. let us
+ * start timer to handle this asynchronous activity.
+ */
+ clear_bit(STATE_IN_BAND_SLEEP_ENABLED, &qca->flags);
+ set_bit(STATE_MEMDUMP_COLLECTION, &qca->flags);
+ dump = (void *) skb->data;
+ dump_size = __le32_to_cpu(dump->dump_size);
+ if (!(dump_size)) {
+ bt_dev_err(hu->hdev, "QCA invalid memdump size");
+ kfree_skb(skb);
+ return;
+ }
+
+ bt_dev_info(hu->hdev, "QCA collecting dump of size:%u",
+ dump_size);
+ mod_timer(&qca->memdump_timer, (jiffies +
+ msecs_to_jiffies(qca->memdump_delay)));
+
+ skb_pull(skb, sizeof(dump_size));
+ memdump_buf = vmalloc(dump_size);
+ qca_memdump->memdump_buf_head = memdump_buf;
+ qca_memdump->memdump_buf_tail = memdump_buf;
+ }
+
+ memdump_buf = qca_memdump->memdump_buf_tail;
+
+ /* If sequence no 0 is missed then there is no point in
+ * accepting the other sequences.
+ */
+ if (!memdump_buf) {
+ bt_dev_err(hu->hdev, "QCA: Discarding other packets");
+ kfree(qca_memdump);
+ kfree_skb(skb);
+ qca->qca_memdump = NULL;
+ return;
+ }
+
+ /* There could be chance of missing some packets from
+ * the controller. In such cases let us store the dummy
+ * packets in the buffer.
+ */
+ while ((seq_no > qca_memdump->current_seq_no + 1) &&
+ seq_no != QCA_LAST_SEQUENCE_NUM) {
+ bt_dev_err(hu->hdev, "QCA controller missed packet:%d",
+ qca_memdump->current_seq_no);
+ memcpy(memdump_buf, nullBuff, QCA_DUMP_PACKET_SIZE);
+ memdump_buf = memdump_buf + QCA_DUMP_PACKET_SIZE;
+ qca_memdump->received_dump += QCA_DUMP_PACKET_SIZE;
+ qca_memdump->current_seq_no++;
+ }
+
+ memcpy(memdump_buf, (unsigned char *) skb->data, skb->len);
+ memdump_buf = memdump_buf + skb->len;
+ qca_memdump->memdump_buf_tail = memdump_buf;
+ qca_memdump->current_seq_no = seq_no + 1;
+ qca_memdump->received_dump += skb->len;
+ qca->qca_memdump = qca_memdump;
+ kfree_skb(skb);
+ if (seq_no == QCA_LAST_SEQUENCE_NUM) {
+ bt_dev_info(hu->hdev, "QCA writing crash dump of size %d bytes",
+ qca_memdump->received_dump);
+ memdump_buf = qca_memdump->memdump_buf_head;
+ dev_coredumpv(&hu->serdev->dev, memdump_buf,
+ qca_memdump->received_dump, GFP_KERNEL);
+ // Revisit for free(memdump) if needed.
+ del_timer(&qca->memdump_timer);
+ kfree(qca->qca_memdump);
+ qca->qca_memdump = NULL;
+ qca->memdump_state = QCA_MEMDUMP_COLLECTED;
+ }
+ }
+
+}
+
+int qca_controller_memdump_event(struct hci_dev *hdev, struct sk_buff *skb)
+{
+ struct hci_uart *hu = hci_get_drvdata(hdev);
+ struct qca_data *qca = hu->priv;
+
+ skb_queue_tail(&qca->rx_memdump_q, skb);
+ queue_work(qca->workqueue, &qca->ctrl_memdump_evt);
+
+ return 0;
+}
+
+static int qca_recv_event(struct hci_dev *hdev, struct sk_buff *skb)
+{
+ /* We receive chip memory dump as an event packet, With a dedicated
+ * handler followed by a hardware error event. When this event is
+ * received we store dump into a file before closing hci. This
+ * dump will help in triaging the issues.
+ */
+ if ((skb->data[0] == HCI_VENDOR_PKT) &&
+ (get_unaligned_be16(skb->data + 2) == QCA_SSR_DUMP_HANDLE))
+ return qca_controller_memdump_event(hdev, skb);
+
+ return hci_recv_frame(hdev, skb);
+}
+
#define QCA_IBS_SLEEP_IND_EVENT \
.type = HCI_IBS_SLEEP_IND, \
.hlen = 0, \
@@ -891,7 +1093,7 @@ static int qca_recv_acl_data(struct hci_dev *hdev, struct sk_buff *skb)
static const struct h4_recv_pkt qca_recv_pkts[] = {
{ H4_RECV_ACL, .recv = qca_recv_acl_data },
{ H4_RECV_SCO, .recv = hci_recv_frame },
- { H4_RECV_EVENT, .recv = hci_recv_frame },
+ { H4_RECV_EVENT, .recv = qca_recv_event },
{ QCA_IBS_WAKE_IND_EVENT, .recv = qca_ibs_wake_ind },
{ QCA_IBS_WAKE_ACK_EVENT, .recv = qca_ibs_wake_ack },
{ QCA_IBS_SLEEP_IND_EVENT, .recv = qca_ibs_sleep_ind },
@@ -1126,6 +1328,83 @@ static int qca_set_speed(struct hci_uart *hu, enum qca_speed_type speed_type)
return ret;
}

+static int qca_send_crashbuffer(struct hci_uart *hu)
+{
+ struct qca_data *qca = hu->priv;
+ struct sk_buff *skb;
+
+ bt_dev_info(hu->hdev, "sending soc crash buffer to controller");
+ skb = bt_skb_alloc(QCA_CRASHBYTE_PACKET_LEN, GFP_KERNEL);
+ if (!skb) {
+ bt_dev_err(hu->hdev, "Failed to allocate memory for skb packet");
+ return -ENOMEM;
+ }
+
+ /* We forcefully crash the controller, by sending 0xfb byte for
+ * 1024 times. We also might have chance of losing data, To be
+ * on safer side we send 1100 bytes to the SoC.
+ */
+ memset(skb_push(skb, QCA_CRASHBYTE_PACKET_LEN), QCA_MEMDUMP_BYTE,
+ QCA_CRASHBYTE_PACKET_LEN);
+ hci_skb_pkt_type(skb) = HCI_COMMAND_PKT;
+ skb_queue_tail(&qca->txq, skb);
+ hci_uart_tx_wakeup(hu);
+
+ return 0;
+}
+
+static void qca_wait_for_dump_collection(struct hci_dev *hdev)
+{
+ struct hci_uart *hu = hci_get_drvdata(hdev);
+ struct qca_data *qca = hu->priv;
+ struct qca_memdump_data *qca_memdump = qca->qca_memdump;
+ char *memdump_buf = qca_memdump->memdump_buf_tail;
+ int err;
+
+ wait_on_bit_timeout(&qca->flags, STATE_MEMDUMP_COLLECTION,
+ TASK_UNINTERRUPTIBLE, qca->memdump_delay);
+
+ clear_bit(STATE_MEMDUMP_COLLECTION, &qca->flags);
+ if (err || qca->memdump_state == QCA_MEMDUMP_IDLE) {
+ bt_dev_err(hu->hdev, "Clearing the buffers due to timeout");
+ if (qca_memdump)
+ memdump_buf = qca_memdump->memdump_buf_tail;
+ kfree(memdump_buf);
+ kfree(qca_memdump);
+ qca->memdump_state = QCA_MEMDUMP_TIMEOUT;
+ del_timer(&qca->memdump_timer);
+ cancel_work_sync(&qca->ctrl_memdump_evt);
+ }
+}
+
+static void qca_hw_error(struct hci_dev *hdev, u8 code)
+{
+ struct hci_uart *hu = hci_get_drvdata(hdev);
+ struct qca_data *qca = hu->priv;
+
+ bt_dev_info(hdev, "mem_dump_status: %d", qca->memdump_state);
+
+ if (qca->memdump_state == QCA_MEMDUMP_IDLE) {
+ /* If hardware error event received for other than QCA
+ * soc memory dump event, then we need to crash the SOC
+ * and wait here for 8 seconds to get the dump packets.
+ * This will block main thread to be on hold until we
+ * collect dump.
+ */
+ set_bit(STATE_MEMDUMP_COLLECTION, &qca->flags);
+ qca_send_crashbuffer(hu);
+ qca_wait_for_dump_collection(hdev);
+ } else if (qca->memdump_state == QCA_MEMDUMP_COLLECTING) {
+ /* Let us wait here until memory dump collected or
+ * memory dump timer expired.
+ */
+ bt_dev_info(hdev, "waiting for dump to complete");
+ qca_wait_for_dump_collection(hdev);
+ }
+
+ qca->memdump_state = QCA_MEMDUMP_IDLE;
+}
+
static int qca_wcn3990_init(struct hci_uart *hu)
{
struct qca_serdev *qcadev;
@@ -1238,6 +1517,10 @@ static int qca_setup(struct hci_uart *hu)
if (!ret) {
set_bit(STATE_IN_BAND_SLEEP_ENABLED, &qca->flags);
qca_debugfs_init(hdev);
+ /* We only get controller dump when fw download is
+ * successful.
+ */
+ hu->hdev->hw_error = qca_hw_error;
} else if (ret == -ENOENT) {
/* No patch/nvm-config found, run with original fw/config */
ret = 0;
--
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