diff mbox series

[v7,1/4] Bluetooth: Add support for hci devcoredump

Message ID 20230302151413.v7.1.I9b4e4818bab450657b19cda3497d363c9baa616e@changeid
State Superseded
Headers show
Series [v7,1/4] Bluetooth: Add support for hci devcoredump | expand

Commit Message

Manish Mandlik March 2, 2023, 11:15 p.m. UTC
From: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>

Add devcoredump APIs to hci core so that drivers only have to provide
the dump skbs instead of managing the synchronization and timeouts.

The devcoredump APIs should be used in the following manner:
 - hci_devcoredump_init is called to allocate the dump.
 - hci_devcoredump_append is called to append any skbs with dump data
   OR hci_devcoredump_append_pattern is called to insert a pattern.
 - hci_devcoredump_complete is called when all dump packets have been
   sent OR hci_devcoredump_abort is called to indicate an error and
   cancel an ongoing dump collection.

The high level APIs just prepare some skbs with the appropriate data and
queue it for the dump to process. Packets part of the crashdump can be
intercepted in the driver in interrupt context and forwarded directly to
the devcoredump APIs.

Internally, there are 5 states for the dump: idle, active, complete,
abort and timeout. A devcoredump will only be in active state after it
has been initialized. Once active, it accepts data to be appended,
patterns to be inserted (i.e. memset) and a completion event or an abort
event to generate a devcoredump. The timeout is initialized at the same
time the dump is initialized (defaulting to 10s) and will be cleared
either when the timeout occurs or the dump is complete or aborted.

Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
Signed-off-by: Manish Mandlik <mmandlik@google.com>
Reviewed-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
---

(no changes since v6)

Changes in v6:
- Remove #ifdef from .c and move to function in .h as per suggestion
- Remove coredump_enabled from hci_devcoredump struct since the sysfs
  flag related change has been abandoned

Changes in v4:
- Add .enabled() and .coredump() to hci_devcoredump struct

Changes in v3:
- Add attribute to enable/disable and set default state to disabled

Changes in v2:
- Move hci devcoredump implementation to new files
- Move dump queue and dump work to hci_devcoredump struct
- Add CONFIG_DEV_COREDUMP conditional compile

 include/net/bluetooth/coredump.h | 114 +++++++
 include/net/bluetooth/hci_core.h |  14 +
 net/bluetooth/Makefile           |   2 +
 net/bluetooth/coredump.c         | 515 +++++++++++++++++++++++++++++++
 net/bluetooth/hci_core.c         |   1 +
 net/bluetooth/hci_sync.c         |   2 +
 6 files changed, 648 insertions(+)
 create mode 100644 include/net/bluetooth/coredump.h
 create mode 100644 net/bluetooth/coredump.c

Comments

Luiz Augusto von Dentz March 3, 2023, 12:32 a.m. UTC | #1
Hi Manish,

On Thu, Mar 2, 2023 at 3:15 PM Manish Mandlik <mmandlik@google.com> wrote:
>
> Add devcoredump support for vhci that creates forcce_devcoredump debugfs
> entry. This is used for mgmt-tester tests.
>
> Signed-off-by: Manish Mandlik <mmandlik@google.com>
> ---
>
> Changes in v7:
> - New patch in the series
>
>  drivers/bluetooth/Kconfig    |  1 +
>  drivers/bluetooth/hci_vhci.c | 72 ++++++++++++++++++++++++++++++++++++
>  2 files changed, 73 insertions(+)
>
> diff --git a/drivers/bluetooth/Kconfig b/drivers/bluetooth/Kconfig
> index 5a1a7bec3c42..7bc7a765ad69 100644
> --- a/drivers/bluetooth/Kconfig
> +++ b/drivers/bluetooth/Kconfig
> @@ -363,6 +363,7 @@ config BT_HCIBLUECARD
>
>  config BT_HCIVHCI
>         tristate "HCI VHCI (Virtual HCI device) driver"
> +       select WANT_DEV_COREDUMP
>         help
>           Bluetooth Virtual HCI device driver.
>           This driver is required if you want to use HCI Emulation software.
> diff --git a/drivers/bluetooth/hci_vhci.c b/drivers/bluetooth/hci_vhci.c
> index c443c3b0a4da..8a74e66f8b8e 100644
> --- a/drivers/bluetooth/hci_vhci.c
> +++ b/drivers/bluetooth/hci_vhci.c
> @@ -278,6 +278,75 @@ static int vhci_setup(struct hci_dev *hdev)
>         return 0;
>  }
>
> +static void vhci_coredump(struct hci_dev *hdev)
> +{
> +       /* No need to do anything */
> +}
> +
> +static int vhci_coredump_hdr(struct hci_dev *hdev, char *buf, size_t size)
> +{
> +       char *ptr = buf;
> +       size_t rem = size;
> +       size_t read = 0;
> +
> +       read = snprintf(ptr, rem, "Controller Name: vhci_ctrl\n");
> +       rem -= read;
> +       ptr += read;

Don't really like these pointer operations, can't we pass the skb here
and then use the likes of skb_push?

> +       read = snprintf(ptr, rem, "Firmware Version: vhci_fw\n");
> +       rem -= read;
> +       ptr += read;
> +
> +       read = snprintf(ptr, rem, "Driver: vhci_drv\n");
> +       rem -= read;
> +       ptr += read;
> +
> +       read = snprintf(ptr, rem, "Vendor: vhci\n");
> +       rem -= read;
> +       ptr += read;
> +
> +       return size - rem;
> +}
> +
> +static ssize_t force_devcoredump_write(struct file *file,
> +                                      const char __user *user_buf,
> +                                      size_t count, loff_t *ppos)
> +{
> +       struct vhci_data *data = file->private_data;
> +       struct hci_dev *hdev = data->hdev;
> +       struct sk_buff *skb = NULL;
> +       char buf[512];
> +       int ret;
> +
> +       ret = simple_write_to_buffer(&buf, sizeof(buf), ppos, user_buf, count);
> +       if (ret < count)
> +               return ret;
> +
> +       skb = alloc_skb(count, GFP_ATOMIC);
> +       if (!skb)
> +               return -ENOMEM;
> +       skb_put_data(skb, &buf, count);
> +
> +       hci_devcoredump_register(hdev, vhci_coredump, vhci_coredump_hdr, NULL);
> +
> +       ret = hci_devcoredump_init(hdev, skb->len);
> +       if (ret) {
> +               BT_ERR("Failed to generate devcoredump");
> +               kfree_skb(skb);
> +               return ret;
> +       }
> +
> +       hci_devcoredump_append(hdev, skb);
> +       hci_devcoredump_complete(hdev);
> +
> +       return count;
> +}
> +
> +static const struct file_operations force_devcoredump_fops = {
> +       .open           = simple_open,
> +       .write          = force_devcoredump_write,
> +};
> +
>  static int __vhci_create_device(struct vhci_data *data, __u8 opcode)
>  {
>         struct hci_dev *hdev;
> @@ -355,6 +424,9 @@ static int __vhci_create_device(struct vhci_data *data, __u8 opcode)
>                 debugfs_create_file("aosp_capable", 0644, hdev->debugfs, data,
>                                     &aosp_capable_fops);
>
> +       debugfs_create_file("force_devcoredump", 0644, hdev->debugfs, data,
> +                           &force_devcoredump_fops);
> +
>         hci_skb_pkt_type(skb) = HCI_VENDOR_PKT;
>
>         skb_put_u8(skb, 0xff);
> --
> 2.40.0.rc0.216.gc4246ad0f0-goog
>
bluez.test.bot@gmail.com March 3, 2023, 2:39 a.m. UTC | #2
This is automated email and please do not reply to this email!

Dear submitter,

Thank you for submitting the patches to the linux bluetooth mailing list.
This is a CI test results with your patch series:
PW Link:https://patchwork.kernel.org/project/bluetooth/list/?series=726259

---Test result---

Test Summary:
CheckPatch                    FAIL      5.34 seconds
GitLint                       PASS      0.94 seconds
SubjectPrefix                 PASS      0.24 seconds
BuildKernel                   PASS      38.30 seconds
CheckAllWarning               PASS      41.72 seconds
CheckSparse                   PASS      47.01 seconds
CheckSmatch                   PASS      127.02 seconds
BuildKernel32                 PASS      36.80 seconds
TestRunnerSetup               PASS      520.01 seconds
TestRunner_l2cap-tester       PASS      18.28 seconds
TestRunner_iso-tester         PASS      20.23 seconds
TestRunner_bnep-tester        PASS      6.61 seconds
TestRunner_mgmt-tester        PASS      126.52 seconds
TestRunner_rfcomm-tester      PASS      10.49 seconds
TestRunner_sco-tester         PASS      9.64 seconds
TestRunner_ioctl-tester       PASS      11.37 seconds
TestRunner_mesh-tester        PASS      8.43 seconds
TestRunner_smp-tester         PASS      9.46 seconds
TestRunner_userchan-tester    PASS      6.96 seconds
IncrementalBuild              PASS      53.41 seconds

Details
##############################
Test: CheckPatch - FAIL
Desc: Run checkpatch.pl script
Output:
[v7,1/4] Bluetooth: Add support for hci devcoredump
WARNING: added, moved or deleted file(s), does MAINTAINERS need updating?
#145: 
new file mode 100644

WARNING: quoted string split across lines
#621: FILE: net/bluetooth/coredump.c:300:
+				    "Devcoredump complete with size %u "
+				    "(expect %zu)",

WARNING: quoted string split across lines
#640: FILE: net/bluetooth/coredump.c:319:
+				    "Devcoredump aborted with size %u "
+				    "(expect %zu)",

WARNING: Possible unnecessary 'out of memory' message
#734: FILE: net/bluetooth/coredump.c:413:
+	if (!skb) {
+		bt_dev_err(hdev, "Failed to allocate devcoredump init");

WARNING: Possible unnecessary 'out of memory' message
#777: FILE: net/bluetooth/coredump.c:456:
+	if (!skb) {
+		bt_dev_err(hdev, "Failed to allocate devcoredump pattern");

WARNING: Possible unnecessary 'out of memory' message
#803: FILE: net/bluetooth/coredump.c:482:
+	if (!skb) {
+		bt_dev_err(hdev, "Failed to allocate devcoredump complete");

WARNING: Possible unnecessary 'out of memory' message
#825: FILE: net/bluetooth/coredump.c:504:
+	if (!skb) {
+		bt_dev_err(hdev, "Failed to allocate devcoredump abort");

total: 0 errors, 7 warnings, 0 checks, 684 lines checked

NOTE: For some of the reported defects, checkpatch may be able to
      mechanically convert to the typical style using --fix or --fix-inplace.

/github/workspace/src/src/13158029.patch has style problems, please review.

NOTE: Ignored message types: UNKNOWN_COMMIT_ID

NOTE: If any of the errors are false positives, please report
      them to the maintainer, see CHECKPATCH in MAINTAINERS.




---
Regards,
Linux Bluetooth
diff mbox series

Patch

diff --git a/include/net/bluetooth/coredump.h b/include/net/bluetooth/coredump.h
new file mode 100644
index 000000000000..5da253527cfe
--- /dev/null
+++ b/include/net/bluetooth/coredump.h
@@ -0,0 +1,114 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2022 Google Corporation
+ */
+
+#ifndef __COREDUMP_H
+#define __COREDUMP_H
+
+#define DEVCOREDUMP_TIMEOUT	msecs_to_jiffies(10000)	/* 10 sec */
+
+typedef void (*coredump_t)(struct hci_dev *hdev);
+typedef int  (*dmp_hdr_t)(struct hci_dev *hdev, char *buf, size_t size);
+typedef void (*notify_change_t)(struct hci_dev *hdev, int state);
+
+/* struct hci_devcoredump - Devcoredump state
+ *
+ * @supported: Indicates if FW dump collection is supported by driver
+ * @state: Current state of dump collection
+ * @alloc_size: Total size of the dump
+ * @head: Start of the dump
+ * @tail: Pointer to current end of dump
+ * @end: head + alloc_size for easy comparisons
+ *
+ * @dump_q: Dump queue for state machine to process
+ * @dump_rx: Devcoredump state machine work
+ * @dump_timeout: Devcoredump timeout work
+ *
+ * @coredump: Called from the driver's .coredump() function.
+ * @dmp_hdr: Create a dump header to identify controller/fw/driver info
+ * @notify_change: Notify driver when devcoredump state has changed
+ */
+struct hci_devcoredump {
+	bool		supported;
+
+	enum devcoredump_state {
+		HCI_DEVCOREDUMP_IDLE,
+		HCI_DEVCOREDUMP_ACTIVE,
+		HCI_DEVCOREDUMP_DONE,
+		HCI_DEVCOREDUMP_ABORT,
+		HCI_DEVCOREDUMP_TIMEOUT
+	} state;
+
+	size_t		alloc_size;
+	char		*head;
+	char		*tail;
+	char		*end;
+
+	struct sk_buff_head	dump_q;
+	struct work_struct	dump_rx;
+	struct delayed_work	dump_timeout;
+
+	coredump_t		coredump;
+	dmp_hdr_t		dmp_hdr;
+	notify_change_t		notify_change;
+};
+
+#ifdef CONFIG_DEV_COREDUMP
+
+void hci_devcoredump_reset(struct hci_dev *hdev);
+void hci_devcoredump_rx(struct work_struct *work);
+void hci_devcoredump_timeout(struct work_struct *work);
+
+int hci_devcoredump_register(struct hci_dev *hdev, coredump_t coredump,
+			     dmp_hdr_t dmp_hdr, notify_change_t notify_change);
+int hci_devcoredump_init(struct hci_dev *hdev, u32 dmp_size);
+int hci_devcoredump_append(struct hci_dev *hdev, struct sk_buff *skb);
+int hci_devcoredump_append_pattern(struct hci_dev *hdev, u8 pattern, u32 len);
+int hci_devcoredump_complete(struct hci_dev *hdev);
+int hci_devcoredump_abort(struct hci_dev *hdev);
+
+#else
+
+static inline void hci_devcoredump_reset(struct hci_dev *hdev) {}
+static inline void hci_devcoredump_rx(struct work_struct *work) {}
+static inline void hci_devcoredump_timeout(struct work_struct *work) {}
+
+static inline int hci_devcoredump_register(struct hci_dev *hdev,
+					   coredump_t coredump,
+					   dmp_hdr_t dmp_hdr,
+					   notify_change_t notify_change)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int hci_devcoredump_init(struct hci_dev *hdev, u32 dmp_size)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int hci_devcoredump_append(struct hci_dev *hdev,
+					 struct sk_buff *skb)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int hci_devcoredump_append_pattern(struct hci_dev *hdev,
+						 u8 pattern, u32 len)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int hci_devcoredump_complete(struct hci_dev *hdev)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int hci_devcoredump_abort(struct hci_dev *hdev)
+{
+	return -EOPNOTSUPP;
+}
+
+#endif /* CONFIG_DEV_COREDUMP */
+
+#endif /* __COREDUMP_H */
diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 9488671c1219..e405fd4d25db 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -32,6 +32,7 @@ 
 #include <net/bluetooth/hci.h>
 #include <net/bluetooth/hci_sync.h>
 #include <net/bluetooth/hci_sock.h>
+#include <net/bluetooth/coredump.h>
 
 /* HCI priority */
 #define HCI_PRIO_MAX	7
@@ -590,6 +591,10 @@  struct hci_dev {
 	const char		*fw_info;
 	struct dentry		*debugfs;
 
+#ifdef CONFIG_DEV_COREDUMP
+	struct hci_devcoredump	dump;
+#endif
+
 	struct device		dev;
 
 	struct rfkill		*rfkill;
@@ -1496,6 +1501,15 @@  static inline void hci_set_aosp_capable(struct hci_dev *hdev)
 #endif
 }
 
+static inline void hci_devcoredump_setup(struct hci_dev *hdev)
+{
+#ifdef CONFIG_DEV_COREDUMP
+	INIT_WORK(&hdev->dump.dump_rx, hci_devcoredump_rx);
+	INIT_DELAYED_WORK(&hdev->dump.dump_timeout, hci_devcoredump_timeout);
+	skb_queue_head_init(&hdev->dump.dump_q);
+#endif
+}
+
 int hci_dev_open(__u16 dev);
 int hci_dev_close(__u16 dev);
 int hci_dev_do_close(struct hci_dev *hdev);
diff --git a/net/bluetooth/Makefile b/net/bluetooth/Makefile
index 0e7b7db42750..141ac1fda0bf 100644
--- a/net/bluetooth/Makefile
+++ b/net/bluetooth/Makefile
@@ -17,6 +17,8 @@  bluetooth-y := af_bluetooth.o hci_core.o hci_conn.o hci_event.o mgmt.o \
 	ecdh_helper.o hci_request.o mgmt_util.o mgmt_config.o hci_codec.o \
 	eir.o hci_sync.o
 
+bluetooth-$(CONFIG_DEV_COREDUMP) += coredump.o
+
 bluetooth-$(CONFIG_BT_BREDR) += sco.o
 bluetooth-$(CONFIG_BT_LE) += iso.o
 bluetooth-$(CONFIG_BT_HS) += a2mp.o amp.o
diff --git a/net/bluetooth/coredump.c b/net/bluetooth/coredump.c
new file mode 100644
index 000000000000..ce9e36f77323
--- /dev/null
+++ b/net/bluetooth/coredump.c
@@ -0,0 +1,515 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2022 Google Corporation
+ */
+
+#include <linux/devcoredump.h>
+
+#include <net/bluetooth/bluetooth.h>
+#include <net/bluetooth/hci_core.h>
+
+enum hci_devcoredump_pkt_type {
+	HCI_DEVCOREDUMP_PKT_INIT,
+	HCI_DEVCOREDUMP_PKT_SKB,
+	HCI_DEVCOREDUMP_PKT_PATTERN,
+	HCI_DEVCOREDUMP_PKT_COMPLETE,
+	HCI_DEVCOREDUMP_PKT_ABORT,
+};
+
+struct hci_devcoredump_skb_cb {
+	u16 pkt_type;
+};
+
+struct hci_devcoredump_skb_pattern {
+	u8 pattern;
+	u32 len;
+} __packed;
+
+#define hci_dmp_cb(skb)	((struct hci_devcoredump_skb_cb *)((skb)->cb))
+
+#define MAX_DEVCOREDUMP_HDR_SIZE	512	/* bytes */
+
+static int hci_devcoredump_update_hdr_state(char *buf, size_t size, int state)
+{
+	if (!buf)
+		return 0;
+
+	return snprintf(buf, size, "Bluetooth devcoredump\nState: %d\n", state);
+}
+
+/* Call with hci_dev_lock only. */
+static int hci_devcoredump_update_state(struct hci_dev *hdev, int state)
+{
+	hdev->dump.state = state;
+
+	return hci_devcoredump_update_hdr_state(hdev->dump.head,
+						hdev->dump.alloc_size, state);
+}
+
+static int hci_devcoredump_mkheader(struct hci_dev *hdev, char *buf,
+				    size_t buf_size)
+{
+	char *ptr = buf;
+	size_t rem = buf_size;
+	size_t read = 0;
+
+	read = hci_devcoredump_update_hdr_state(ptr, rem, HCI_DEVCOREDUMP_IDLE);
+	read += 1; /* update_hdr_state adds \0 at the end upon state rewrite */
+	rem -= read;
+	ptr += read;
+
+	if (hdev->dump.dmp_hdr) {
+		/* dmp_hdr() should return number of bytes written */
+		read = hdev->dump.dmp_hdr(hdev, ptr, rem);
+		rem -= read;
+		ptr += read;
+	}
+
+	read = snprintf(ptr, rem, "--- Start dump ---\n");
+	rem -= read;
+	ptr += read;
+
+	return buf_size - rem;
+}
+
+/* Do not call with hci_dev_lock since this calls driver code. */
+static void hci_devcoredump_notify(struct hci_dev *hdev, int state)
+{
+	if (hdev->dump.notify_change)
+		hdev->dump.notify_change(hdev, state);
+}
+
+/* Call with hci_dev_lock only. */
+void hci_devcoredump_reset(struct hci_dev *hdev)
+{
+	hdev->dump.head = NULL;
+	hdev->dump.tail = NULL;
+	hdev->dump.alloc_size = 0;
+
+	hci_devcoredump_update_state(hdev, HCI_DEVCOREDUMP_IDLE);
+
+	cancel_delayed_work(&hdev->dump.dump_timeout);
+	skb_queue_purge(&hdev->dump.dump_q);
+}
+
+/* Call with hci_dev_lock only. */
+static void hci_devcoredump_free(struct hci_dev *hdev)
+{
+	if (hdev->dump.head)
+		vfree(hdev->dump.head);
+
+	hci_devcoredump_reset(hdev);
+}
+
+/* Call with hci_dev_lock only. */
+static int hci_devcoredump_alloc(struct hci_dev *hdev, u32 size)
+{
+	hdev->dump.head = vmalloc(size);
+	if (!hdev->dump.head)
+		return -ENOMEM;
+
+	hdev->dump.alloc_size = size;
+	hdev->dump.tail = hdev->dump.head;
+	hdev->dump.end = hdev->dump.head + size;
+
+	hci_devcoredump_update_state(hdev, HCI_DEVCOREDUMP_IDLE);
+
+	return 0;
+}
+
+/* Call with hci_dev_lock only. */
+static bool hci_devcoredump_copy(struct hci_dev *hdev, char *buf, u32 size)
+{
+	if (hdev->dump.tail + size > hdev->dump.end)
+		return false;
+
+	memcpy(hdev->dump.tail, buf, size);
+	hdev->dump.tail += size;
+
+	return true;
+}
+
+/* Call with hci_dev_lock only. */
+static bool hci_devcoredump_memset(struct hci_dev *hdev, u8 pattern, u32 len)
+{
+	if (hdev->dump.tail + len > hdev->dump.end)
+		return false;
+
+	memset(hdev->dump.tail, pattern, len);
+	hdev->dump.tail += len;
+
+	return true;
+}
+
+/* Call with hci_dev_lock only. */
+static int hci_devcoredump_prepare(struct hci_dev *hdev, u32 dump_size)
+{
+	char *dump_hdr;
+	int dump_hdr_size;
+	u32 size;
+	int err = 0;
+
+	dump_hdr = vmalloc(MAX_DEVCOREDUMP_HDR_SIZE);
+	if (!dump_hdr) {
+		err = -ENOMEM;
+		goto hdr_free;
+	}
+
+	dump_hdr_size = hci_devcoredump_mkheader(hdev, dump_hdr,
+						 MAX_DEVCOREDUMP_HDR_SIZE);
+	size = dump_hdr_size + dump_size;
+
+	if (hci_devcoredump_alloc(hdev, size)) {
+		err = -ENOMEM;
+		goto hdr_free;
+	}
+
+	/* Insert the device header */
+	if (!hci_devcoredump_copy(hdev, dump_hdr, dump_hdr_size)) {
+		bt_dev_err(hdev, "Failed to insert header");
+		hci_devcoredump_free(hdev);
+
+		err = -ENOMEM;
+		goto hdr_free;
+	}
+
+hdr_free:
+	if (dump_hdr)
+		vfree(dump_hdr);
+
+	return err;
+}
+
+/* Bluetooth devcoredump state machine.
+ *
+ * Devcoredump states:
+ *
+ *      HCI_DEVCOREDUMP_IDLE: The default state.
+ *
+ *      HCI_DEVCOREDUMP_ACTIVE: A devcoredump will be in this state once it has
+ *              been initialized using hci_devcoredump_init(). Once active, the
+ *              driver can append data using hci_devcoredump_append() or insert
+ *              a pattern using hci_devcoredump_append_pattern().
+ *
+ *      HCI_DEVCOREDUMP_DONE: Once the dump collection is complete, the drive
+ *              can signal the completion using hci_devcoredump_complete(). A
+ *              devcoredump is generated indicating the completion event and
+ *              then the state machine is reset to the default state.
+ *
+ *      HCI_DEVCOREDUMP_ABORT: The driver can cancel ongoing dump collection in
+ *              case of any error using hci_devcoredump_abort(). A devcoredump
+ *              is still generated with the available data indicating the abort
+ *              event and then the state machine is reset to the default state.
+ *
+ *      HCI_DEVCOREDUMP_TIMEOUT: A timeout timer for HCI_DEVCOREDUMP_TIMEOUT sec
+ *              is started during devcoredump initialization. Once the timeout
+ *              occurs, the driver is notified, a devcoredump is generated with
+ *              the available data indicating the timeout event and then the
+ *              state machine is reset to the default state.
+ *
+ * The driver must register using hci_devcoredump_register() before using the
+ * hci devcoredump APIs.
+ */
+void hci_devcoredump_rx(struct work_struct *work)
+{
+	struct hci_dev *hdev = container_of(work, struct hci_dev, dump.dump_rx);
+	struct sk_buff *skb;
+	struct hci_devcoredump_skb_pattern *pattern;
+	u32 dump_size;
+	int start_state;
+
+#define DBG_UNEXPECTED_STATE() \
+		bt_dev_dbg(hdev, \
+			   "Unexpected packet (%d) for state (%d). ", \
+			   hci_dmp_cb(skb)->pkt_type, hdev->dump.state)
+
+	while ((skb = skb_dequeue(&hdev->dump.dump_q))) {
+		hci_dev_lock(hdev);
+		start_state = hdev->dump.state;
+
+		switch (hci_dmp_cb(skb)->pkt_type) {
+		case HCI_DEVCOREDUMP_PKT_INIT:
+			if (hdev->dump.state != HCI_DEVCOREDUMP_IDLE) {
+				DBG_UNEXPECTED_STATE();
+				goto loop_continue;
+			}
+
+			if (skb->len != sizeof(dump_size)) {
+				bt_dev_dbg(hdev, "Invalid dump init pkt");
+				goto loop_continue;
+			}
+
+			dump_size = *((u32 *)skb->data);
+			if (!dump_size) {
+				bt_dev_err(hdev, "Zero size dump init pkt");
+				goto loop_continue;
+			}
+
+			if (hci_devcoredump_prepare(hdev, dump_size)) {
+				bt_dev_err(hdev, "Failed to prepare for dump");
+				goto loop_continue;
+			}
+
+			hci_devcoredump_update_state(hdev,
+						     HCI_DEVCOREDUMP_ACTIVE);
+			queue_delayed_work(hdev->workqueue,
+					   &hdev->dump.dump_timeout,
+					   DEVCOREDUMP_TIMEOUT);
+			break;
+
+		case HCI_DEVCOREDUMP_PKT_SKB:
+			if (hdev->dump.state != HCI_DEVCOREDUMP_ACTIVE) {
+				DBG_UNEXPECTED_STATE();
+				goto loop_continue;
+			}
+
+			if (!hci_devcoredump_copy(hdev, skb->data, skb->len))
+				bt_dev_dbg(hdev, "Failed to insert skb");
+			break;
+
+		case HCI_DEVCOREDUMP_PKT_PATTERN:
+			if (hdev->dump.state != HCI_DEVCOREDUMP_ACTIVE) {
+				DBG_UNEXPECTED_STATE();
+				goto loop_continue;
+			}
+
+			if (skb->len != sizeof(*pattern)) {
+				bt_dev_dbg(hdev, "Invalid pattern skb");
+				goto loop_continue;
+			}
+
+			pattern = (void *)skb->data;
+
+			if (!hci_devcoredump_memset(hdev, pattern->pattern,
+						    pattern->len))
+				bt_dev_dbg(hdev, "Failed to set pattern");
+			break;
+
+		case HCI_DEVCOREDUMP_PKT_COMPLETE:
+			if (hdev->dump.state != HCI_DEVCOREDUMP_ACTIVE) {
+				DBG_UNEXPECTED_STATE();
+				goto loop_continue;
+			}
+
+			hci_devcoredump_update_state(hdev,
+						     HCI_DEVCOREDUMP_DONE);
+			dump_size = hdev->dump.tail - hdev->dump.head;
+
+			bt_dev_info(hdev,
+				    "Devcoredump complete with size %u "
+				    "(expect %zu)",
+				    dump_size, hdev->dump.alloc_size);
+
+			dev_coredumpv(&hdev->dev, hdev->dump.head, dump_size,
+				      GFP_KERNEL);
+			break;
+
+		case HCI_DEVCOREDUMP_PKT_ABORT:
+			if (hdev->dump.state != HCI_DEVCOREDUMP_ACTIVE) {
+				DBG_UNEXPECTED_STATE();
+				goto loop_continue;
+			}
+
+			hci_devcoredump_update_state(hdev,
+						     HCI_DEVCOREDUMP_ABORT);
+			dump_size = hdev->dump.tail - hdev->dump.head;
+
+			bt_dev_info(hdev,
+				    "Devcoredump aborted with size %u "
+				    "(expect %zu)",
+				    dump_size, hdev->dump.alloc_size);
+
+			/* Emit a devcoredump with the available data */
+			dev_coredumpv(&hdev->dev, hdev->dump.head, dump_size,
+				      GFP_KERNEL);
+			break;
+
+		default:
+			bt_dev_dbg(hdev,
+				   "Unknown packet (%d) for state (%d). ",
+				   hci_dmp_cb(skb)->pkt_type, hdev->dump.state);
+			break;
+		}
+
+loop_continue:
+		kfree_skb(skb);
+		hci_dev_unlock(hdev);
+
+		if (start_state != hdev->dump.state)
+			hci_devcoredump_notify(hdev, hdev->dump.state);
+
+		hci_dev_lock(hdev);
+		if (hdev->dump.state == HCI_DEVCOREDUMP_DONE ||
+		    hdev->dump.state == HCI_DEVCOREDUMP_ABORT)
+			hci_devcoredump_reset(hdev);
+		hci_dev_unlock(hdev);
+	}
+}
+EXPORT_SYMBOL(hci_devcoredump_rx);
+
+void hci_devcoredump_timeout(struct work_struct *work)
+{
+	struct hci_dev *hdev = container_of(work, struct hci_dev,
+					    dump.dump_timeout.work);
+	u32 dump_size;
+
+	hci_devcoredump_notify(hdev, HCI_DEVCOREDUMP_TIMEOUT);
+
+	hci_dev_lock(hdev);
+
+	cancel_work_sync(&hdev->dump.dump_rx);
+
+	hci_devcoredump_update_state(hdev, HCI_DEVCOREDUMP_TIMEOUT);
+	dump_size = hdev->dump.tail - hdev->dump.head;
+	bt_dev_info(hdev, "Devcoredump timeout with size %u (expect %zu)",
+		    dump_size, hdev->dump.alloc_size);
+
+	/* Emit a devcoredump with the available data */
+	dev_coredumpv(&hdev->dev, hdev->dump.head, dump_size, GFP_KERNEL);
+
+	hci_devcoredump_reset(hdev);
+
+	hci_dev_unlock(hdev);
+}
+EXPORT_SYMBOL(hci_devcoredump_timeout);
+
+int hci_devcoredump_register(struct hci_dev *hdev, coredump_t coredump,
+			     dmp_hdr_t dmp_hdr, notify_change_t notify_change)
+{
+	/* Driver must implement coredump() and dmp_hdr() functions for
+	 * bluetooth devcoredump. The coredump() should trigger a coredump
+	 * event on the controller when the device's coredump sysfs entry is
+	 * written to. The dmp_hdr() should create a dump header to identify
+	 * the controller/fw/driver info.
+	 */
+	if (!coredump || !dmp_hdr)
+		return -EINVAL;
+
+	hci_dev_lock(hdev);
+	hdev->dump.coredump = coredump;
+	hdev->dump.dmp_hdr = dmp_hdr;
+	hdev->dump.notify_change = notify_change;
+	hdev->dump.supported = true;
+	hci_dev_unlock(hdev);
+
+	return 0;
+}
+EXPORT_SYMBOL(hci_devcoredump_register);
+
+static inline bool hci_devcoredump_enabled(struct hci_dev *hdev)
+{
+	return hdev->dump.supported;
+}
+
+int hci_devcoredump_init(struct hci_dev *hdev, u32 dmp_size)
+{
+	struct sk_buff *skb = NULL;
+
+	if (!hci_devcoredump_enabled(hdev))
+		return -EOPNOTSUPP;
+
+	skb = alloc_skb(sizeof(dmp_size), GFP_ATOMIC);
+	if (!skb) {
+		bt_dev_err(hdev, "Failed to allocate devcoredump init");
+		return -ENOMEM;
+	}
+
+	hci_dmp_cb(skb)->pkt_type = HCI_DEVCOREDUMP_PKT_INIT;
+	skb_put_data(skb, &dmp_size, sizeof(dmp_size));
+
+	skb_queue_tail(&hdev->dump.dump_q, skb);
+	queue_work(hdev->workqueue, &hdev->dump.dump_rx);
+
+	return 0;
+}
+EXPORT_SYMBOL(hci_devcoredump_init);
+
+int hci_devcoredump_append(struct hci_dev *hdev, struct sk_buff *skb)
+{
+	if (!skb)
+		return -ENOMEM;
+
+	if (!hci_devcoredump_enabled(hdev)) {
+		kfree_skb(skb);
+		return -EOPNOTSUPP;
+	}
+
+	hci_dmp_cb(skb)->pkt_type = HCI_DEVCOREDUMP_PKT_SKB;
+
+	skb_queue_tail(&hdev->dump.dump_q, skb);
+	queue_work(hdev->workqueue, &hdev->dump.dump_rx);
+
+	return 0;
+}
+EXPORT_SYMBOL(hci_devcoredump_append);
+
+int hci_devcoredump_append_pattern(struct hci_dev *hdev, u8 pattern, u32 len)
+{
+	struct hci_devcoredump_skb_pattern p;
+	struct sk_buff *skb = NULL;
+
+	if (!hci_devcoredump_enabled(hdev))
+		return -EOPNOTSUPP;
+
+	skb = alloc_skb(sizeof(p), GFP_ATOMIC);
+	if (!skb) {
+		bt_dev_err(hdev, "Failed to allocate devcoredump pattern");
+		return -ENOMEM;
+	}
+
+	p.pattern = pattern;
+	p.len = len;
+
+	hci_dmp_cb(skb)->pkt_type = HCI_DEVCOREDUMP_PKT_PATTERN;
+	skb_put_data(skb, &p, sizeof(p));
+
+	skb_queue_tail(&hdev->dump.dump_q, skb);
+	queue_work(hdev->workqueue, &hdev->dump.dump_rx);
+
+	return 0;
+}
+EXPORT_SYMBOL(hci_devcoredump_append_pattern);
+
+int hci_devcoredump_complete(struct hci_dev *hdev)
+{
+	struct sk_buff *skb = NULL;
+
+	if (!hci_devcoredump_enabled(hdev))
+		return -EOPNOTSUPP;
+
+	skb = alloc_skb(0, GFP_ATOMIC);
+	if (!skb) {
+		bt_dev_err(hdev, "Failed to allocate devcoredump complete");
+		return -ENOMEM;
+	}
+
+	hci_dmp_cb(skb)->pkt_type = HCI_DEVCOREDUMP_PKT_COMPLETE;
+
+	skb_queue_tail(&hdev->dump.dump_q, skb);
+	queue_work(hdev->workqueue, &hdev->dump.dump_rx);
+
+	return 0;
+}
+EXPORT_SYMBOL(hci_devcoredump_complete);
+
+int hci_devcoredump_abort(struct hci_dev *hdev)
+{
+	struct sk_buff *skb = NULL;
+
+	if (!hci_devcoredump_enabled(hdev))
+		return -EOPNOTSUPP;
+
+	skb = alloc_skb(0, GFP_ATOMIC);
+	if (!skb) {
+		bt_dev_err(hdev, "Failed to allocate devcoredump abort");
+		return -ENOMEM;
+	}
+
+	hci_dmp_cb(skb)->pkt_type = HCI_DEVCOREDUMP_PKT_ABORT;
+
+	skb_queue_tail(&hdev->dump.dump_q, skb);
+	queue_work(hdev->workqueue, &hdev->dump.dump_rx);
+
+	return 0;
+}
+EXPORT_SYMBOL(hci_devcoredump_abort);
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 334e308451f5..37aa70192ccb 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -2544,6 +2544,7 @@  struct hci_dev *hci_alloc_dev_priv(int sizeof_priv)
 	INIT_DELAYED_WORK(&hdev->cmd_timer, hci_cmd_timeout);
 	INIT_DELAYED_WORK(&hdev->ncmd_timer, hci_ncmd_timeout);
 
+	hci_devcoredump_setup(hdev);
 	hci_request_setup(hdev);
 
 	hci_init_sysfs(hdev);
diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
index 561a519a11bd..e0423867ff19 100644
--- a/net/bluetooth/hci_sync.c
+++ b/net/bluetooth/hci_sync.c
@@ -4722,6 +4722,8 @@  int hci_dev_open_sync(struct hci_dev *hdev)
 		goto done;
 	}
 
+	hci_devcoredump_reset(hdev);
+
 	set_bit(HCI_RUNNING, &hdev->flags);
 	hci_sock_dev_event(hdev, HCI_DEV_OPEN);