[PATCH v2 0/5] In-kernel QMI helpers and sysmon

[PATCH v2 0/5] In-kernel QMI helpers and sysmon

[Bjorn Andersson]

This series introduces a helper library for drivers that needs to implement
clients or services in the kernel for communicating with QMI encoded messages.

This is used by a set of drivers in order to implement control signaling that
needs to happen between a driver and a service on a remote processor, such as
the synchronization of states during a remoteproc shutdown/restart; as seen in
the sysmon implementation.

Finally a sample driver provides an implementation of the "test" protocol,
which is a service typically implemented by Qualcomm remoteproc firmware.

Changes since v1:
- Lot of modifications to QMI interface, from feedback and implementation and
  testing of sysmon.
- Added sysmon driver.
- Added patch for remoteproc to pass gracefulness on subdev remove.
- QRTR patches part of v1 was merged separately

Bjorn Andersson (5):
  soc: qcom: Introduce QMI encoder/decoder
  soc: qcom: Introduce QMI helpers
  remoteproc: Pass type of shutdown to subdev remove
  remoteproc: qcom: Introduce sysmon
  samples: Introduce Qualcomm QMI sample client

 drivers/remoteproc/Kconfig           |  17 +
 drivers/remoteproc/Makefile          |   1 +
 drivers/remoteproc/qcom_adsp_pil.c   |  12 +
 drivers/remoteproc/qcom_common.c     |   6 +-
 drivers/remoteproc/qcom_common.h     |  21 +
 drivers/remoteproc/qcom_q6v5_pil.c   |   3 +
 drivers/remoteproc/qcom_sysmon.c     | 585 ++++++++++++++++++++++++
 drivers/remoteproc/qcom_wcnss.c      |   4 +
 drivers/remoteproc/remoteproc_core.c |  18 +-
 drivers/soc/qcom/Kconfig             |   9 +
 drivers/soc/qcom/Makefile            |   3 +
 drivers/soc/qcom/qmi_encdec.c        | 812 +++++++++++++++++++++++++++++++++
 drivers/soc/qcom/qmi_interface.c     | 849 +++++++++++++++++++++++++++++++++++
 include/linux/remoteproc.h           |   4 +-
 include/linux/soc/qcom/qmi.h         | 273 +++++++++++
 samples/Kconfig                      |   9 +
 samples/Makefile                     |   2 +-
 samples/qmi/Makefile                 |   1 +
 samples/qmi/qmi_sample_client.c      | 631 ++++++++++++++++++++++++++
 19 files changed, 3245 insertions(+), 15 deletions(-)
 create mode 100644 drivers/remoteproc/qcom_sysmon.c
 create mode 100644 drivers/soc/qcom/qmi_encdec.c
 create mode 100644 drivers/soc/qcom/qmi_interface.c
 create mode 100644 include/linux/soc/qcom/qmi.h
 create mode 100644 samples/qmi/Makefile
 create mode 100644 samples/qmi/qmi_sample_client.c

-- 
2.15.0

[PATCH v2 1/5] soc: qcom: Introduce QMI encoder/decoder

[Bjorn Andersson]

Add the helper library for encoding and decoding QMI encoded messages.
The implementation is taken from lib/qmi_encdec.c of the Qualcomm kernel
(msm-3.18).

Modifications has been made to the public API, source buffers has been
made const and the debug-logging part was omitted, for now.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
---

Changes since v1:
- None 

 drivers/soc/qcom/Kconfig      |   8 +
 drivers/soc/qcom/Makefile     |   2 +
 drivers/soc/qcom/qmi_encdec.c | 812 ++++++++++++++++++++++++++++++++++++++++++
 include/linux/soc/qcom/qmi.h  | 116 ++++++
 4 files changed, 938 insertions(+)
 create mode 100644 drivers/soc/qcom/qmi_encdec.c
 create mode 100644 include/linux/soc/qcom/qmi.h

diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
index b00bccddcd3b..91b70b170a82 100644
--- a/drivers/soc/qcom/Kconfig
+++ b/drivers/soc/qcom/Kconfig
@@ -35,6 +35,14 @@ config QCOM_PM
 	  modes. It interface with various system drivers to put the cores in
 	  low power modes.
 
+config QCOM_QMI_HELPERS
+	tristate
+	help
+	  Helper library for handling QMI encoded messages.  QMI encoded
+	  messages are used in communication between the majority of QRTR
+	  clients and this helpers provide the common functionality needed for
+	  doing this from a kernel driver.
+
 config QCOM_SMEM
 	tristate "Qualcomm Shared Memory Manager (SMEM)"
 	depends on ARCH_QCOM
diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
index f151de41eb93..625750acfeef 100644
--- a/drivers/soc/qcom/Makefile
+++ b/drivers/soc/qcom/Makefile
@@ -2,6 +2,8 @@ obj-$(CONFIG_QCOM_GLINK_SSR) +=	glink_ssr.o
 obj-$(CONFIG_QCOM_GSBI)	+=	qcom_gsbi.o
 obj-$(CONFIG_QCOM_MDT_LOADER)	+= mdt_loader.o
 obj-$(CONFIG_QCOM_PM)	+=	spm.o
+obj-$(CONFIG_QCOM_QMI_HELPERS)	+= qmi_helpers.o
+qmi_helpers-y	+= qmi_encdec.o
 obj-$(CONFIG_QCOM_SMD_RPM)	+= smd-rpm.o
 obj-$(CONFIG_QCOM_SMEM) +=	smem.o
 obj-$(CONFIG_QCOM_SMEM_STATE) += smem_state.o
diff --git a/drivers/soc/qcom/qmi_encdec.c b/drivers/soc/qcom/qmi_encdec.c
new file mode 100644
index 000000000000..a3131f11a03c
--- /dev/null
+++ b/drivers/soc/qcom/qmi_encdec.c
@@ -0,0 +1,812 @@
+/*
+ * Copyright (c) 2012-2015, The Linux Foundation. All rights reserved.
+ * Copyright (C) 2017 Linaro Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/io.h>
+#include <linux/string.h>
+#include <linux/soc/qcom/qmi.h>
+
+#define QMI_ENCDEC_ENCODE_TLV(type, length, p_dst) do { \
+	*p_dst++ = type; \
+	*p_dst++ = ((uint8_t)((length) & 0xFF)); \
+	*p_dst++ = ((uint8_t)(((length) >> 8) & 0xFF)); \
+} while (0)
+
+#define QMI_ENCDEC_DECODE_TLV(p_type, p_length, p_src) do { \
+	*p_type = (uint8_t)*p_src++; \
+	*p_length = (uint8_t)*p_src++; \
+	*p_length |= ((uint8_t)*p_src) << 8; \
+} while (0)
+
+#define QMI_ENCDEC_ENCODE_N_BYTES(p_dst, p_src, size) \
+do { \
+	memcpy(p_dst, p_src, size); \
+	p_dst = (uint8_t *)p_dst + size; \
+	p_src = (uint8_t *)p_src + size; \
+} while (0)
+
+#define QMI_ENCDEC_DECODE_N_BYTES(p_dst, p_src, size) \
+do { \
+	memcpy(p_dst, p_src, size); \
+	p_dst = (uint8_t *)p_dst + size; \
+	p_src = (uint8_t *)p_src + size; \
+} while (0)
+
+#define UPDATE_ENCODE_VARIABLES(temp_si, buf_dst, \
+				encoded_bytes, tlv_len, encode_tlv, rc) \
+do { \
+	buf_dst = (uint8_t *)buf_dst + rc; \
+	encoded_bytes += rc; \
+	tlv_len += rc; \
+	temp_si = temp_si + 1; \
+	encode_tlv = 1; \
+} while (0)
+
+#define UPDATE_DECODE_VARIABLES(buf_src, decoded_bytes, rc) \
+do { \
+	buf_src = (uint8_t *)buf_src + rc; \
+	decoded_bytes += rc; \
+} while (0)
+
+#define TLV_LEN_SIZE sizeof(uint16_t)
+#define TLV_TYPE_SIZE sizeof(uint8_t)
+#define OPTIONAL_TLV_TYPE_START 0x10
+
+static int qmi_encode(struct qmi_elem_info *ei_array, void *out_buf,
+		      const void *in_c_struct, uint32_t out_buf_len,
+		      int enc_level);
+
+static int qmi_decode(struct qmi_elem_info *ei_array, void *out_c_struct,
+		      const void *in_buf, uint32_t in_buf_len, int dec_level);
+
+/**
+ * skip_to_next_elem() - Skip to next element in the structure to be encoded
+ * @ei_array: Struct info describing the element to be skipped.
+ * @level: Depth level of encoding/decoding to identify nested structures.
+ *
+ * Returns struct info of the next element that can be encoded.
+ *
+ * This function is used while encoding optional elements. If the flag
+ * corresponding to an optional element is not set, then encoding the
+ * optional element can be skipped. This function can be used to perform
+ * that operation.
+ */
+static struct qmi_elem_info *skip_to_next_elem(struct qmi_elem_info *ei_array,
+					   int level)
+{
+	struct qmi_elem_info *temp_ei = ei_array;
+	uint8_t tlv_type;
+
+	if (level > 1) {
+		temp_ei = temp_ei + 1;
+	} else {
+		do {
+			tlv_type = temp_ei->tlv_type;
+			temp_ei = temp_ei + 1;
+		} while (tlv_type == temp_ei->tlv_type);
+	}
+
+	return temp_ei;
+}
+
+/**
+ * qmi_calc_min_msg_len() - Calculate the minimum length of a QMI message
+ * @ei_array: Struct info array describing the structure.
+ * @level: Level to identify the depth of the nested structures.
+ *
+ * Returns expected minimum length of the QMI message or 0 on error.
+ */
+static int qmi_calc_min_msg_len(struct qmi_elem_info *ei_array,
+				int level)
+{
+	int min_msg_len = 0;
+	struct qmi_elem_info *temp_ei = ei_array;
+
+	if (!ei_array)
+		return min_msg_len;
+
+	while (temp_ei->data_type != QMI_EOTI) {
+		/* Optional elements do not count in minimum length */
+		if (temp_ei->data_type == QMI_OPT_FLAG) {
+			temp_ei = skip_to_next_elem(temp_ei, level);
+			continue;
+		}
+
+		if (temp_ei->data_type == QMI_DATA_LEN) {
+			min_msg_len += (temp_ei->elem_size == sizeof(uint8_t) ?
+					sizeof(uint8_t) : sizeof(uint16_t));
+			temp_ei++;
+			continue;
+		} else if (temp_ei->data_type == QMI_STRUCT) {
+			min_msg_len += qmi_calc_min_msg_len(temp_ei->ei_array,
+							    (level + 1));
+			temp_ei++;
+		} else if (temp_ei->data_type == QMI_STRING) {
+			if (level > 1)
+				min_msg_len += temp_ei->elem_len <= U8_MAX ?
+					sizeof(uint8_t) : sizeof(uint16_t);
+			min_msg_len += temp_ei->elem_len * temp_ei->elem_size;
+			temp_ei++;
+		} else {
+			min_msg_len += (temp_ei->elem_len * temp_ei->elem_size);
+			temp_ei++;
+		}
+
+		/*
+		 * Type & Length info. not prepended for elements in the
+		 * nested structure.
+		 */
+		if (level == 1)
+			min_msg_len += (TLV_TYPE_SIZE + TLV_LEN_SIZE);
+	}
+	return min_msg_len;
+}
+
+/**
+ * qmi_encode_basic_elem() - Encodes elements of basic/primary data type
+ * @buf_dst: Buffer to store the encoded information.
+ * @buf_src: Buffer containing the elements to be encoded.
+ * @elem_len: Number of elements, in the buf_src, to be encoded.
+ * @elem_size: Size of a single instance of the element to be encoded.
+ *
+ * Returns the number of bytes of encoded information.
+ *
+ * This function encodes the "elem_len" number of data elements, each of
+ * size "elem_size" bytes from the source buffer "buf_src" and stores the
+ * encoded information in the destination buffer "buf_dst". The elements are
+ * of primary data type which include uint8_t - uint64_t or similar. This
+ * function returns the number of bytes of encoded information.
+ */
+static int qmi_encode_basic_elem(void *buf_dst, const void *buf_src,
+				 uint32_t elem_len, uint32_t elem_size)
+{
+	uint32_t i, rc = 0;
+
+	for (i = 0; i < elem_len; i++) {
+		QMI_ENCDEC_ENCODE_N_BYTES(buf_dst, buf_src, elem_size);
+		rc += elem_size;
+	}
+
+	return rc;
+}
+
+/**
+ * qmi_encode_struct_elem() - Encodes elements of struct data type
+ * @ei_array: Struct info array descibing the struct element.
+ * @buf_dst: Buffer to store the encoded information.
+ * @buf_src: Buffer containing the elements to be encoded.
+ * @elem_len: Number of elements, in the buf_src, to be encoded.
+ * @out_buf_len: Available space in the encode buffer.
+ * @enc_level: Depth of the nested structure from the main structure.
+ *
+ * Returns the number of bytes of encoded information on success or negative
+ * errno on error.
+ *
+ * This function encodes the "elem_len" number of struct elements, each of
+ * size "ei_array->elem_size" bytes from the source buffer "buf_src" and
+ * stores the encoded information in the destination buffer "buf_dst". The
+ * elements are of struct data type which includes any C structure. This
+ * function returns the number of bytes of encoded information.
+ */
+static int qmi_encode_struct_elem(struct qmi_elem_info *ei_array,
+				  void *buf_dst, const void *buf_src,
+				  uint32_t elem_len, uint32_t out_buf_len,
+				  int enc_level)
+{
+	int i, rc, encoded_bytes = 0;
+	struct qmi_elem_info *temp_ei = ei_array;
+
+	for (i = 0; i < elem_len; i++) {
+		rc = qmi_encode(temp_ei->ei_array, buf_dst, buf_src,
+				out_buf_len - encoded_bytes, enc_level);
+		if (rc < 0) {
+			pr_err("%s: STRUCT Encode failure\n", __func__);
+			return rc;
+		}
+		buf_dst = buf_dst + rc;
+		buf_src = buf_src + temp_ei->elem_size;
+		encoded_bytes += rc;
+	}
+
+	return encoded_bytes;
+}
+
+/**
+ * qmi_encode_string_elem() - Encodes elements of string data type
+ * @ei_array: Struct info array descibing the string element.
+ * @buf_dst: Buffer to store the encoded information.
+ * @buf_src: Buffer containing the elements to be encoded.
+ * @out_buf_len: Available space in the encode buffer.
+ * @enc_level: Depth of the string element from the main structure.
+ *
+ * Returns the number of bytes of encoded information on success or negative
+ * errno on error.
+ *
+ * This function encodes a string element of maximum length "ei_array->elem_len"
+ * bytes from the source buffer "buf_src" and stores the encoded information in
+ * the destination buffer "buf_dst". This function returns the number of bytes
+ * of encoded information.
+ */
+static int qmi_encode_string_elem(struct qmi_elem_info *ei_array,
+				  void *buf_dst, const void *buf_src,
+				  uint32_t out_buf_len, int enc_level)
+{
+	int rc;
+	int encoded_bytes = 0;
+	struct qmi_elem_info *temp_ei = ei_array;
+	uint32_t string_len = 0;
+	uint32_t string_len_sz = 0;
+
+	string_len = strlen(buf_src);
+	string_len_sz = temp_ei->elem_len <= U8_MAX ?
+			sizeof(uint8_t) : sizeof(uint16_t);
+	if (string_len > temp_ei->elem_len) {
+		pr_err("%s: String to be encoded is longer - %d > %d\n",
+			__func__, string_len, temp_ei->elem_len);
+		return -EINVAL;
+	}
+
+	if (enc_level == 1) {
+		if (string_len + TLV_LEN_SIZE + TLV_TYPE_SIZE >
+		    out_buf_len) {
+			pr_err("%s: Output len %d > Out Buf len %d\n",
+				__func__, string_len, out_buf_len);
+			return -ETOOSMALL;
+		}
+	} else {
+		if (string_len + string_len_sz > out_buf_len) {
+			pr_err("%s: Output len %d > Out Buf len %d\n",
+				__func__, string_len, out_buf_len);
+			return -ETOOSMALL;
+		}
+		rc = qmi_encode_basic_elem(buf_dst, &string_len,
+					   1, string_len_sz);
+		encoded_bytes += rc;
+	}
+
+	rc = qmi_encode_basic_elem(buf_dst + encoded_bytes, buf_src,
+				   string_len, temp_ei->elem_size);
+	encoded_bytes += rc;
+	return encoded_bytes;
+}
+
+/**
+ * qmi_encode() - Core Encode Function
+ * @ei_array: Struct info array describing the structure to be encoded.
+ * @out_buf: Buffer to hold the encoded QMI message.
+ * @in_c_struct: Pointer to the C structure to be encoded.
+ * @out_buf_len: Available space in the encode buffer.
+ * @enc_level: Encode level to indicate the depth of the nested structure,
+ *             within the main structure, being encoded.
+ *
+ * Returns the number of bytes of encoded information on success or negative
+ * errno on error.
+ */
+static int qmi_encode(struct qmi_elem_info *ei_array, void *out_buf,
+		      const void *in_c_struct, uint32_t out_buf_len,
+		      int enc_level)
+{
+	struct qmi_elem_info *temp_ei = ei_array;
+	uint8_t opt_flag_value = 0;
+	uint32_t data_len_value = 0, data_len_sz;
+	uint8_t *buf_dst = (uint8_t *)out_buf;
+	uint8_t *tlv_pointer;
+	uint32_t tlv_len;
+	uint8_t tlv_type;
+	uint32_t encoded_bytes = 0;
+	const void *buf_src;
+	int encode_tlv = 0;
+	int rc;
+
+	if (!ei_array)
+		return 0;
+
+	tlv_pointer = buf_dst;
+	tlv_len = 0;
+	if (enc_level == 1)
+		buf_dst = buf_dst + (TLV_LEN_SIZE + TLV_TYPE_SIZE);
+
+	while (temp_ei->data_type != QMI_EOTI) {
+		buf_src = in_c_struct + temp_ei->offset;
+		tlv_type = temp_ei->tlv_type;
+
+		if (temp_ei->is_array == NO_ARRAY) {
+			data_len_value = 1;
+		} else if (temp_ei->is_array == STATIC_ARRAY) {
+			data_len_value = temp_ei->elem_len;
+		} else if (data_len_value <= 0 ||
+			    temp_ei->elem_len < data_len_value) {
+			pr_err("%s: Invalid data length\n", __func__);
+			return -EINVAL;
+		}
+
+		switch (temp_ei->data_type) {
+		case QMI_OPT_FLAG:
+			rc = qmi_encode_basic_elem(&opt_flag_value, buf_src,
+						   1, sizeof(uint8_t));
+			if (opt_flag_value)
+				temp_ei = temp_ei + 1;
+			else
+				temp_ei = skip_to_next_elem(temp_ei, enc_level);
+			break;
+
+		case QMI_DATA_LEN:
+			memcpy(&data_len_value, buf_src, temp_ei->elem_size);
+			data_len_sz = temp_ei->elem_size == sizeof(uint8_t) ?
+					sizeof(uint8_t) : sizeof(uint16_t);
+			/* Check to avoid out of range buffer access */
+			if ((data_len_sz + encoded_bytes + TLV_LEN_SIZE +
+			    TLV_TYPE_SIZE) > out_buf_len) {
+				pr_err("%s: Too Small Buffer @DATA_LEN\n",
+					__func__);
+				return -ETOOSMALL;
+			}
+			rc = qmi_encode_basic_elem(buf_dst, &data_len_value,
+						   1, data_len_sz);
+			UPDATE_ENCODE_VARIABLES(temp_ei, buf_dst,
+				encoded_bytes, tlv_len, encode_tlv, rc);
+			if (!data_len_value)
+				temp_ei = skip_to_next_elem(temp_ei, enc_level);
+			else
+				encode_tlv = 0;
+			break;
+
+		case QMI_UNSIGNED_1_BYTE:
+		case QMI_UNSIGNED_2_BYTE:
+		case QMI_UNSIGNED_4_BYTE:
+		case QMI_UNSIGNED_8_BYTE:
+		case QMI_SIGNED_2_BYTE_ENUM:
+		case QMI_SIGNED_4_BYTE_ENUM:
+			/* Check to avoid out of range buffer access */
+			if (((data_len_value * temp_ei->elem_size) +
+			    encoded_bytes + TLV_LEN_SIZE + TLV_TYPE_SIZE) >
+			    out_buf_len) {
+				pr_err("%s: Too Small Buffer @data_type:%d\n",
+					__func__, temp_ei->data_type);
+				return -ETOOSMALL;
+			}
+			rc = qmi_encode_basic_elem(buf_dst, buf_src,
+				data_len_value, temp_ei->elem_size);
+			UPDATE_ENCODE_VARIABLES(temp_ei, buf_dst,
+				encoded_bytes, tlv_len, encode_tlv, rc);
+			break;
+
+		case QMI_STRUCT:
+			rc = qmi_encode_struct_elem(temp_ei, buf_dst, buf_src,
+				data_len_value, (out_buf_len - encoded_bytes),
+				(enc_level + 1));
+			if (rc < 0)
+				return rc;
+			UPDATE_ENCODE_VARIABLES(temp_ei, buf_dst,
+				encoded_bytes, tlv_len, encode_tlv, rc);
+			break;
+
+		case QMI_STRING:
+			rc = qmi_encode_string_elem(temp_ei, buf_dst, buf_src,
+				out_buf_len - encoded_bytes, enc_level);
+			if (rc < 0)
+				return rc;
+			UPDATE_ENCODE_VARIABLES(temp_ei, buf_dst,
+				encoded_bytes, tlv_len, encode_tlv, rc);
+			break;
+		default:
+			pr_err("%s: Unrecognized data type\n", __func__);
+			return -EINVAL;
+
+		}
+
+		if (encode_tlv && enc_level == 1) {
+			QMI_ENCDEC_ENCODE_TLV(tlv_type, tlv_len, tlv_pointer);
+			encoded_bytes += (TLV_TYPE_SIZE + TLV_LEN_SIZE);
+			tlv_pointer = buf_dst;
+			tlv_len = 0;
+			buf_dst = buf_dst + TLV_LEN_SIZE + TLV_TYPE_SIZE;
+			encode_tlv = 0;
+		}
+	}
+	return encoded_bytes;
+}
+
+/**
+ * qmi_decode_basic_elem() - Decodes elements of basic/primary data type
+ * @buf_dst: Buffer to store the decoded element.
+ * @buf_src: Buffer containing the elements in QMI wire format.
+ * @elem_len: Number of elements to be decoded.
+ * @elem_size: Size of a single instance of the element to be decoded.
+ *
+ * Returns the total size of the decoded data elements, in bytes.
+ *
+ * This function decodes the "elem_len" number of elements in QMI wire format,
+ * each of size "elem_size" bytes from the source buffer "buf_src" and stores
+ * the decoded elements in the destination buffer "buf_dst". The elements are
+ * of primary data type which include uint8_t - uint64_t or similar. This
+ * function returns the number of bytes of decoded information.
+ */
+static int qmi_decode_basic_elem(void *buf_dst, const void *buf_src,
+				 uint32_t elem_len, uint32_t elem_size)
+{
+	uint32_t i, rc = 0;
+
+	for (i = 0; i < elem_len; i++) {
+		QMI_ENCDEC_DECODE_N_BYTES(buf_dst, buf_src, elem_size);
+		rc += elem_size;
+	}
+
+	return rc;
+}
+
+/**
+ * qmi_decode_struct_elem() - Decodes elements of struct data type
+ * @ei_array: Struct info array descibing the struct element.
+ * @buf_dst: Buffer to store the decoded element.
+ * @buf_src: Buffer containing the elements in QMI wire format.
+ * @elem_len: Number of elements to be decoded.
+ * @tlv_len: Total size of the encoded inforation corresponding to
+ *           this struct element.
+ * @dec_level: Depth of the nested structure from the main structure.
+ *
+ * Returns the total size of the decoded data elements on success, negative
+ * errno on error.
+ *
+ * This function decodes the "elem_len" number of elements in QMI wire format,
+ * each of size "(tlv_len/elem_len)" bytes from the source buffer "buf_src"
+ * and stores the decoded elements in the destination buffer "buf_dst". The
+ * elements are of struct data type which includes any C structure. This
+ * function returns the number of bytes of decoded information.
+ */
+static int qmi_decode_struct_elem(struct qmi_elem_info *ei_array,
+				  void *buf_dst, const void *buf_src,
+				  uint32_t elem_len, uint32_t tlv_len,
+				  int dec_level)
+{
+	int i, rc, decoded_bytes = 0;
+	struct qmi_elem_info *temp_ei = ei_array;
+
+	for (i = 0; i < elem_len && decoded_bytes < tlv_len; i++) {
+		rc = qmi_decode(temp_ei->ei_array, buf_dst, buf_src,
+				tlv_len - decoded_bytes, dec_level);
+		if (rc < 0)
+			return rc;
+		buf_src = buf_src + rc;
+		buf_dst = buf_dst + temp_ei->elem_size;
+		decoded_bytes += rc;
+	}
+
+	if ((dec_level <= 2 && decoded_bytes != tlv_len) ||
+	    (dec_level > 2 && (i < elem_len || decoded_bytes > tlv_len))) {
+		pr_err("%s: Fault in decoding: dl(%d), db(%d), tl(%d), i(%d), el(%d)\n",
+			__func__, dec_level, decoded_bytes, tlv_len,
+			i, elem_len);
+		return -EFAULT;
+	}
+	return decoded_bytes;
+}
+
+/**
+ * qmi_decode_string_elem() - Decodes elements of string data type
+ * @ei_array: Struct info array descibing the string element.
+ * @buf_dst: Buffer to store the decoded element.
+ * @buf_src: Buffer containing the elements in QMI wire format.
+ * @tlv_len: Total size of the encoded inforation corresponding to
+ *           this string element.
+ * @dec_level: Depth of the string element from the main structure.
+ *
+
+ * Returns the total size of the decoded data elements on success, negative
+ * errno on error.
+
+ *
+ * This function decodes the string element of maximum length
+ * "ei_array->elem_len" from the source buffer "buf_src" and puts it into
+ * the destination buffer "buf_dst". This function returns number of bytes
+ * decoded from the input buffer.
+ */
+static int qmi_decode_string_elem(struct qmi_elem_info *ei_array,
+				  void *buf_dst, const void *buf_src,
+				  uint32_t tlv_len, int dec_level)
+{
+	int rc;
+	int decoded_bytes = 0;
+	uint32_t string_len = 0;
+	uint32_t string_len_sz = 0;
+	struct qmi_elem_info *temp_ei = ei_array;
+
+	if (dec_level == 1) {
+		string_len = tlv_len;
+	} else {
+		string_len_sz = temp_ei->elem_len <= U8_MAX ?
+				sizeof(uint8_t) : sizeof(uint16_t);
+		rc = qmi_decode_basic_elem(&string_len, buf_src,
+					   1, string_len_sz);
+		decoded_bytes += rc;
+	}
+
+	if (string_len > temp_ei->elem_len) {
+		pr_err("%s: String len %d > Max Len %d\n",
+			__func__, string_len, temp_ei->elem_len);
+		return -ETOOSMALL;
+	} else if (string_len > tlv_len) {
+		pr_err("%s: String len %d > Input Buffer Len %d\n",
+			__func__, string_len, tlv_len);
+		return -EFAULT;
+	}
+
+	rc = qmi_decode_basic_elem(buf_dst, buf_src + decoded_bytes,
+				   string_len, temp_ei->elem_size);
+	*((char *)buf_dst + string_len) = '\0';
+	decoded_bytes += rc;
+	return decoded_bytes;
+}
+
+/**
+ * find_ei() - Find element info corresponding to TLV Type
+ * @ei_array: Struct info array of the message being decoded.
+ * @type: TLV Type of the element being searched.
+ *
+ * Returns pointer to struct info, if found
+ *
+ * Every element that got encoded in the QMI message will have a type
+ * information associated with it. While decoding the QMI message,
+ * this function is used to find the struct info regarding the element
+ * that corresponds to the type being decoded.
+ */
+static struct qmi_elem_info *find_ei(struct qmi_elem_info *ei_array,
+				   uint32_t type)
+{
+	struct qmi_elem_info *temp_ei = ei_array;
+	while (temp_ei->data_type != QMI_EOTI) {
+		if (temp_ei->tlv_type == (uint8_t)type)
+			return temp_ei;
+		temp_ei = temp_ei + 1;
+	}
+	return NULL;
+}
+
+/**
+ * qmi_decode() - Core Decode Function
+ * @ei_array: Struct info array describing the structure to be decoded.
+ * @out_c_struct: Buffer to hold the decoded C struct
+ * @in_buf: Buffer containing the QMI message to be decoded
+ * @in_buf_len: Length of the QMI message to be decoded
+ * @dec_level: Decode level to indicate the depth of the nested structure,
+ *             within the main structure, being decoded
+ *
+ * Returns the number of bytes of decoded information on success, negative
+ * errno on error.
+ */
+static int qmi_decode(struct qmi_elem_info *ei_array, void *out_c_struct,
+		      const void *in_buf, uint32_t in_buf_len,
+		      int dec_level)
+{
+	struct qmi_elem_info *temp_ei = ei_array;
+	uint8_t opt_flag_value = 1;
+	uint32_t data_len_value = 0, data_len_sz = 0;
+	uint8_t *buf_dst = out_c_struct;
+	const uint8_t *tlv_pointer;
+	uint32_t tlv_len = 0;
+	uint32_t tlv_type;
+	uint32_t decoded_bytes = 0;
+	const void *buf_src = in_buf;
+	int rc;
+
+	while (decoded_bytes < in_buf_len) {
+		if (dec_level >= 2 && temp_ei->data_type == QMI_EOTI)
+			return decoded_bytes;
+
+		if (dec_level == 1) {
+			tlv_pointer = buf_src;
+			QMI_ENCDEC_DECODE_TLV(&tlv_type,
+					      &tlv_len, tlv_pointer);
+			buf_src += (TLV_TYPE_SIZE + TLV_LEN_SIZE);
+			decoded_bytes += (TLV_TYPE_SIZE + TLV_LEN_SIZE);
+			temp_ei = find_ei(ei_array, tlv_type);
+			if (!temp_ei && (tlv_type < OPTIONAL_TLV_TYPE_START)) {
+				pr_err("%s: Inval element info\n", __func__);
+				return -EINVAL;
+			} else if (!temp_ei) {
+				UPDATE_DECODE_VARIABLES(buf_src,
+						decoded_bytes, tlv_len);
+				continue;
+			}
+		} else {
+			/*
+			 * No length information for elements in nested
+			 * structures. So use remaining decodable buffer space.
+			 */
+			tlv_len = in_buf_len - decoded_bytes;
+		}
+
+		buf_dst = out_c_struct + temp_ei->offset;
+		if (temp_ei->data_type == QMI_OPT_FLAG) {
+			memcpy(buf_dst, &opt_flag_value, sizeof(uint8_t));
+			temp_ei = temp_ei + 1;
+			buf_dst = out_c_struct + temp_ei->offset;
+		}
+
+		if (temp_ei->data_type == QMI_DATA_LEN) {
+			data_len_sz = temp_ei->elem_size == sizeof(uint8_t) ?
+					sizeof(uint8_t) : sizeof(uint16_t);
+			rc = qmi_decode_basic_elem(&data_len_value, buf_src,
+						   1, data_len_sz);
+			memcpy(buf_dst, &data_len_value, sizeof(uint32_t));
+			temp_ei = temp_ei + 1;
+			buf_dst = out_c_struct + temp_ei->offset;
+			tlv_len -= data_len_sz;
+			UPDATE_DECODE_VARIABLES(buf_src, decoded_bytes, rc);
+		}
+
+		if (temp_ei->is_array == NO_ARRAY) {
+			data_len_value = 1;
+		} else if (temp_ei->is_array == STATIC_ARRAY) {
+			data_len_value = temp_ei->elem_len;
+		} else if (data_len_value > temp_ei->elem_len) {
+			pr_err("%s: Data len %d > max spec %d\n",
+				__func__, data_len_value, temp_ei->elem_len);
+			return -ETOOSMALL;
+		}
+
+		switch (temp_ei->data_type) {
+		case QMI_UNSIGNED_1_BYTE:
+		case QMI_UNSIGNED_2_BYTE:
+		case QMI_UNSIGNED_4_BYTE:
+		case QMI_UNSIGNED_8_BYTE:
+		case QMI_SIGNED_2_BYTE_ENUM:
+		case QMI_SIGNED_4_BYTE_ENUM:
+			rc = qmi_decode_basic_elem(buf_dst, buf_src,
+				data_len_value, temp_ei->elem_size);
+			UPDATE_DECODE_VARIABLES(buf_src, decoded_bytes, rc);
+			break;
+
+		case QMI_STRUCT:
+			rc = qmi_decode_struct_elem(temp_ei, buf_dst, buf_src,
+				data_len_value, tlv_len, (dec_level + 1));
+			if (rc < 0)
+				return rc;
+			UPDATE_DECODE_VARIABLES(buf_src, decoded_bytes, rc);
+			break;
+
+		case QMI_STRING:
+			rc = qmi_decode_string_elem(temp_ei, buf_dst, buf_src,
+						     tlv_len, dec_level);
+			if (rc < 0)
+				return rc;
+			UPDATE_DECODE_VARIABLES(buf_src, decoded_bytes, rc);
+			break;
+
+		default:
+			pr_err("%s: Unrecognized data type\n", __func__);
+			return -EINVAL;
+		}
+		temp_ei = temp_ei + 1;
+	}
+	return decoded_bytes;
+}
+
+/**
+ * qmi_encode_message() - Encode C structure as QMI encoded message
+ * @type:	Type of QMI message
+ * @msg_id:	Message ID of the message
+ * @len:	Passed as max length of the message, updated to actual size
+ * @txn_id:	Transaction ID
+ * @ei:		QMI message descriptor
+ * @c_struct:	Reference to structure to encode
+ *
+ * Returns buffer with encoded message, or negative ERR_PTR() on error
+ */
+void *qmi_encode_message(int type, unsigned int msg_id, size_t *len,
+			 unsigned int txn_id, struct qmi_elem_info *ei,
+			 const void *c_struct)
+{
+	struct qmi_header *hdr;
+	ssize_t msglen = 0;
+	void *msg;
+	int ret;
+
+	/* Check the possibility of a zero length QMI message */
+	if (!c_struct) {
+		ret = qmi_calc_min_msg_len(ei, 1);
+		if (ret) {
+			pr_err("%s: Calc. len %d != 0, but NULL c_struct\n",
+				__func__, ret);
+			return ERR_PTR(-EINVAL);
+		}
+	}
+
+	hdr = msg = kzalloc(sizeof(*hdr) + *len, GFP_KERNEL);
+	if (!msg)
+		return ERR_PTR(-ENOMEM);
+
+	msglen = qmi_encode(ei, msg + sizeof(*hdr), c_struct, *len, 1);
+	if (msglen < 0) {
+		kfree(msg);
+		return ERR_PTR(msglen);
+	}
+
+	hdr->type = type;
+	hdr->txn_id = txn_id;
+	hdr->msg_id = msg_id;
+	hdr->msg_len = msglen;
+
+
+	*len = sizeof(*hdr) + msglen;
+
+	return msg;
+}
+EXPORT_SYMBOL(qmi_encode_message);
+
+/**
+ * qmi_decode_message() - Decode QMI encoded message to C structure
+ * @buf:	Buffer with encoded message
+ * @len:	Amount of data in @buf
+ * @ei:		QMI message descriptor
+ * @c_struct:	Reference to structure to decode into
+ *
+ * Returns the number of bytes of decoded information on success, negative
+ * errno on error.
+ */
+int qmi_decode_message(const void *buf, size_t len,
+		       struct qmi_elem_info *ei, void *c_struct)
+{
+	if (!ei)
+		return -EINVAL;
+
+	if (!c_struct || !buf || !len)
+		return -EINVAL;
+
+	return qmi_decode(ei, c_struct, buf + sizeof(struct qmi_header),
+			  len - sizeof(struct qmi_header), 1);
+}
+EXPORT_SYMBOL(qmi_decode_message);
+
+/* Common header in all QMI responses */
+struct qmi_elem_info qmi_response_type_v01_ei[] = {
+	{
+		.data_type	= QMI_SIGNED_2_BYTE_ENUM,
+		.elem_len	= 1,
+		.elem_size	= sizeof(uint16_t),
+		.is_array	= NO_ARRAY,
+		.tlv_type	= QMI_COMMON_TLV_TYPE,
+		.offset		= offsetof(struct qmi_response_type_v01,
+					   result),
+		.ei_array	= NULL,
+	},
+	{
+		.data_type      = QMI_SIGNED_2_BYTE_ENUM,
+		.elem_len       = 1,
+		.elem_size      = sizeof(uint16_t),
+		.is_array       = NO_ARRAY,
+		.tlv_type       = QMI_COMMON_TLV_TYPE,
+		.offset         = offsetof(struct qmi_response_type_v01,
+					   error),
+		.ei_array       = NULL,
+	},
+	{
+		.data_type	= QMI_EOTI,
+		.elem_len	= 0,
+		.elem_size	= 0,
+		.is_array	= NO_ARRAY,
+		.tlv_type	= QMI_COMMON_TLV_TYPE,
+		.offset		= 0,
+		.ei_array	= NULL,
+	},
+};
+EXPORT_SYMBOL(qmi_response_type_v01_ei);
+
+MODULE_DESCRIPTION("QMI encoder/decoder helper");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/soc/qcom/qmi.h b/include/linux/soc/qcom/qmi.h
new file mode 100644
index 000000000000..804d2232c55b
--- /dev/null
+++ b/include/linux/soc/qcom/qmi.h
@@ -0,0 +1,116 @@
+/*
+ * Copyright (c) 2012-2014, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2017, Linaro Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+#ifndef __QMI_HELPERS_H__
+#define __QMI_HELPERS_H__
+
+#include <linux/qrtr.h>
+#include <linux/types.h>
+
+/**
+ * qmi_header - wireformat header of QMI messages
+ * @type:	type of message
+ * @txn_id:	transaction id
+ * @msg_id:	message id
+ * @msg_len:	length of message payload following header
+ */
+struct qmi_header {
+	uint8_t type;
+	uint16_t txn_id;
+	uint16_t msg_id;
+	uint16_t msg_len;
+} __packed;
+
+#define QMI_REQUEST	0
+#define QMI_RESPONSE	2
+#define QMI_INDICATION	4
+
+#define QMI_COMMON_TLV_TYPE 0
+
+enum qmi_elem_type {
+	QMI_EOTI,
+	QMI_OPT_FLAG,
+	QMI_DATA_LEN,
+	QMI_UNSIGNED_1_BYTE,
+	QMI_UNSIGNED_2_BYTE,
+	QMI_UNSIGNED_4_BYTE,
+	QMI_UNSIGNED_8_BYTE,
+	QMI_SIGNED_2_BYTE_ENUM,
+	QMI_SIGNED_4_BYTE_ENUM,
+	QMI_STRUCT,
+	QMI_STRING,
+};
+
+enum qmi_array_type {
+	NO_ARRAY,
+	STATIC_ARRAY,
+	VAR_LEN_ARRAY,
+};
+
+/**
+ * struct qmi_elem_info - describes how to encode a single QMI element
+ * @data_type:	Data type of this element.
+ * @elem_len:	Array length of this element, if an array.
+ * @elem_size:	Size of a single instance of this data type.
+ * @is_array:	Array type of this element.
+ * @tlv_type:	QMI message specific type to identify which element
+ *		is present in an incoming message.
+ * @offset:	Specifies the offset of the first instance of this
+ *		element in the data structure.
+ * @ei_array:	Null-terminated array of @qmi_elem_info to describe nested
+ *		structures.
+ */
+struct qmi_elem_info {
+	enum qmi_elem_type data_type;
+	uint32_t elem_len;
+	uint32_t elem_size;
+	enum qmi_array_type is_array;
+	uint8_t tlv_type;
+	uint32_t offset;
+	struct qmi_elem_info *ei_array;
+};
+
+#define QMI_RESULT_SUCCESS_V01			0
+#define QMI_RESULT_FAILURE_V01			1
+
+#define QMI_ERR_NONE_V01			0
+#define QMI_ERR_MALFORMED_MSG_V01		1
+#define QMI_ERR_NO_MEMORY_V01			2
+#define QMI_ERR_INTERNAL_V01			3
+#define QMI_ERR_CLIENT_IDS_EXHAUSTED_V01	5
+#define QMI_ERR_INVALID_ID_V01			41
+#define QMI_ERR_ENCODING_V01			58
+#define QMI_ERR_INCOMPATIBLE_STATE_V01		90
+#define QMI_ERR_NOT_SUPPORTED_V01		94
+
+/**
+ * qmi_response_type_v01 - common response header (decoded)
+ * @result:	result of the transaction
+ * @error:	error value, when @result is QMI_RESULT_FAILURE_V01
+ */
+struct qmi_response_type_v01 {
+	u16 result;
+	u16 error;
+};
+
+extern struct qmi_elem_info qmi_response_type_v01_ei[];
+
+void *qmi_encode_message(int type, unsigned int msg_id, size_t *len,
+			 unsigned int txn_id, struct qmi_elem_info *ei,
+			 const void *c_struct);
+
+int qmi_decode_message(const void *buf, size_t len,
+		       struct qmi_elem_info *ei, void *c_struct);
+
+
+#endif
-- 
2.15.0

[PATCH v2 2/5] soc: qcom: Introduce QMI helpers

[Bjorn Andersson]

Drivers that needs to communicate with a remote QMI service all has to
perform the operations of discovering the service, encoding and decoding
the messages and operate the socket. This introduces an abstraction for
these common operations, reducing most of the duplication in such cases.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
---

Changes since v1:
- Squashed notion of qmi vs qrtr in interface, to simplify client code
- Lookup and service registration is cached and handled by core on ENETRESET
- Introduce callbacks for BYE and DEL_CLIENT control messages
- Revisited locking for socket and transaction objects, squashed a few races
  and made it possible to send "indication" messages from message handlers.
- kerneldoc updates
- Moved handling of net_reset from clients to this code, greatly simplifies
  typical drivers and reduces duplication
- Pass transaction id of QMI message to handlers even though it's not a
  response, allows sending a response with the txn id of an incoming request.
- Split qmi_send_message() in three, instead of passing type as parameter - to
  clean up handling of "indication" messages.

 drivers/soc/qcom/Kconfig         |   1 +
 drivers/soc/qcom/Makefile        |   1 +
 drivers/soc/qcom/qmi_interface.c | 849 +++++++++++++++++++++++++++++++++++++++
 include/linux/soc/qcom/qmi.h     | 157 ++++++++
 4 files changed, 1008 insertions(+)
 create mode 100644 drivers/soc/qcom/qmi_interface.c

diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
index 91b70b170a82..9718f1c41e3d 100644
--- a/drivers/soc/qcom/Kconfig
+++ b/drivers/soc/qcom/Kconfig
@@ -37,6 +37,7 @@ config QCOM_PM
 
 config QCOM_QMI_HELPERS
 	tristate
+	depends on ARCH_QCOM
 	help
 	  Helper library for handling QMI encoded messages.  QMI encoded
 	  messages are used in communication between the majority of QRTR
diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
index 625750acfeef..b04b5044775f 100644
--- a/drivers/soc/qcom/Makefile
+++ b/drivers/soc/qcom/Makefile
@@ -4,6 +4,7 @@ obj-$(CONFIG_QCOM_MDT_LOADER)	+= mdt_loader.o
 obj-$(CONFIG_QCOM_PM)	+=	spm.o
 obj-$(CONFIG_QCOM_QMI_HELPERS)	+= qmi_helpers.o
 qmi_helpers-y	+= qmi_encdec.o
+qmi_helpers-y	+= qmi_interface.o
 obj-$(CONFIG_QCOM_SMD_RPM)	+= smd-rpm.o
 obj-$(CONFIG_QCOM_SMEM) +=	smem.o
 obj-$(CONFIG_QCOM_SMEM_STATE) += smem_state.o
diff --git a/drivers/soc/qcom/qmi_interface.c b/drivers/soc/qcom/qmi_interface.c
new file mode 100644
index 000000000000..d7885f9b072b
--- /dev/null
+++ b/drivers/soc/qcom/qmi_interface.c
@@ -0,0 +1,849 @@
+/*
+ * Copyright (C) 2017 Linaro Ltd.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/qrtr.h>
+#include <linux/net.h>
+#include <linux/completion.h>
+#include <linux/idr.h>
+#include <linux/string.h>
+#include <net/sock.h>
+#include <linux/workqueue.h>
+#include <linux/soc/qcom/qmi.h>
+
+static struct socket *qmi_sock_create(struct qmi_handle *qmi,
+				      struct sockaddr_qrtr *sq);
+
+/**
+ * qmi_recv_new_server() - handler of NEW_SERVER control message
+ * @qmi:	qmi handle
+ * @node:	node of the new server
+ * @port:	port of the new server
+ *
+ * Calls the new_server callback to inform the client about a newly registered
+ * server matching the currently registered service lookup.
+ */
+static void qmi_recv_new_server(struct qmi_handle *qmi,
+				   unsigned int service, unsigned int instance,
+				   unsigned int node, unsigned int port)
+{
+	struct qmi_ops *ops = &qmi->ops;
+	struct qmi_service *svc;
+	int ret;
+
+	if (!ops->new_server)
+		return;
+
+	/* Ignore EOF marker */
+	if (!node && !port)
+		return;
+
+	svc = kzalloc(sizeof(*svc), GFP_KERNEL);
+	if (!svc)
+		return;
+
+	svc->service = service;
+	svc->version = instance & 0xff;
+	svc->instance = instance >> 8;
+	svc->node = node;
+	svc->port = port;
+
+	ret = ops->new_server(qmi, svc);
+	if (ret < 0)
+		kfree(svc);
+	else
+		list_add(&svc->list_node, &qmi->lookup_results);
+}
+
+/**
+ * qmi_recv_del_server() - handler of DEL_SERVER control message
+ * @qmi:	qmi handle
+ * @node:	node of the dying server, a value of -1 matches all nodes
+ * @port:	port of the dying server, a value of -1 matches all ports
+ *
+ * Calls the del_server callback for each previously seen server, allowing the
+ * client to react to the disappearing server.
+ */
+static void qmi_recv_del_server(struct qmi_handle *qmi,
+				   unsigned int node, unsigned int port)
+{
+	struct qmi_ops *ops = &qmi->ops;
+	struct qmi_service *svc;
+	struct qmi_service *tmp;
+
+	list_for_each_entry_safe(svc, tmp, &qmi->lookup_results, list_node) {
+		if (node != -1 && svc->node != node)
+			continue;
+		if (port != -1 && svc->port != port)
+			continue;
+
+		if (ops->del_server)
+			ops->del_server(qmi, svc);
+
+		list_del(&svc->list_node);
+		kfree(svc);
+	}
+}
+
+/**
+ * qmi_recv_bye() - handler of BYE control message
+ * @qmi:	qmi handle
+ * @node:	id of the dying node
+ *
+ * Signals the client that all previously registered services on this node are
+ * now gone and then calls the bye callback to allow the client client further
+ * cleaning up resources associated with this remote.
+ */
+static void qmi_recv_bye(struct qmi_handle *qmi,
+			    unsigned int node)
+{
+	struct qmi_ops *ops = &qmi->ops;
+
+	qmi_recv_del_server(qmi, node, -1);
+
+	if (ops->bye)
+		ops->bye(qmi, node);
+}
+
+/**
+ * qmi_recv_del_client() - handler of DEL_CLIENT control message
+ * @qmi:	qmi handle
+ * @node:	node of the dying client
+ * @port:	port of the dying client
+ *
+ * Signals the client about a dying client, by calling the del_client callback.
+ */
+static void qmi_recv_del_client(struct qmi_handle *qmi,
+				   unsigned int node, unsigned int port)
+{
+	struct qmi_ops *ops = &qmi->ops;
+
+	if (ops->del_client)
+		ops->del_client(qmi, node, port);
+}
+
+static void qmi_recv_ctrl_pkt(struct qmi_handle *qmi,
+				 const void *buf, size_t len)
+{
+	const struct qrtr_ctrl_pkt *pkt = buf;
+
+	if (len < sizeof(struct qrtr_ctrl_pkt)) {
+		pr_debug("ignoring short control packet\n");
+		return;
+	}
+
+	switch (le32_to_cpu(pkt->cmd)) {
+	case QRTR_TYPE_BYE:
+		qmi_recv_bye(qmi, le32_to_cpu(pkt->client.node));
+		break;
+	case QRTR_TYPE_NEW_SERVER:
+		qmi_recv_new_server(qmi,
+				    le32_to_cpu(pkt->server.service),
+				    le32_to_cpu(pkt->server.instance),
+				    le32_to_cpu(pkt->server.node),
+				    le32_to_cpu(pkt->server.port));
+		break;
+	case QRTR_TYPE_DEL_SERVER:
+		qmi_recv_del_server(qmi,
+				    le32_to_cpu(pkt->server.node),
+				    le32_to_cpu(pkt->server.port));
+		break;
+	case QRTR_TYPE_DEL_CLIENT:
+		qmi_recv_del_client(qmi,
+				    le32_to_cpu(pkt->client.node),
+				    le32_to_cpu(pkt->client.port));
+		break;
+	}
+}
+
+static void qmi_send_new_lookup(struct qmi_handle *qmi, struct qmi_service *svc)
+{
+	struct qrtr_ctrl_pkt pkt;
+	struct sockaddr_qrtr sq;
+	struct msghdr msg = {0};
+	struct kvec iv = { &pkt, sizeof(pkt) };
+	int ret;
+
+	memset(&pkt, 0, sizeof(pkt));
+	pkt.cmd = cpu_to_le32(QRTR_TYPE_NEW_LOOKUP);
+	pkt.server.service = cpu_to_le32(svc->service);
+	pkt.server.instance = cpu_to_le32(svc->version | svc->instance << 8);
+
+	sq.sq_family = qmi->sq.sq_family;
+	sq.sq_node = qmi->sq.sq_node;
+	sq.sq_port = QRTR_PORT_CTRL;
+
+	msg.msg_name = &sq;
+	msg.msg_namelen = sizeof(sq);
+
+	mutex_lock(&qmi->sock_lock);
+	if (qmi->sock) {
+		ret = kernel_sendmsg(qmi->sock, &msg, &iv, 1, sizeof(pkt));
+		if (ret < 0)
+			pr_err("failed to send lookup registration: %d\n", ret);
+	}
+	mutex_unlock(&qmi->sock_lock);
+}
+
+/**
+ * qmi_add_lookup() - register a new lookup with the name service
+ * @qmi:	qmi handle
+ * @service:	service id of the request
+ * @instance:	instance id of the request
+ *
+ * Returns 0 on success, negative errno on failure.
+ *
+ * Registering a lookup query with the name server will cause the name server
+ * to send NEW_SERVER and DEL_SERVER control messages to this socket as
+ * matching services are registered.
+ */
+int qmi_add_lookup(struct qmi_handle *qmi, unsigned int service,
+		   unsigned int version, unsigned int instance)
+{
+	struct qmi_service *svc;
+
+	svc = kzalloc(sizeof(*svc), GFP_KERNEL);
+	if (!svc)
+		return -ENOMEM;
+
+	svc->service = service;
+	svc->version = version;
+	svc->instance = instance;
+
+	list_add(&svc->list_node, &qmi->lookups);
+
+	qmi_send_new_lookup(qmi, svc);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(qmi_add_lookup);
+
+static void qmi_send_new_server(struct qmi_handle *qmi, struct qmi_service *svc)
+{
+	struct qrtr_ctrl_pkt pkt;
+	struct sockaddr_qrtr sq;
+	struct msghdr msg = {0};
+	struct kvec iv = { &pkt, sizeof(pkt) };
+	int ret;
+
+	memset(&pkt, 0, sizeof(pkt));
+	pkt.cmd = cpu_to_le32(QRTR_TYPE_NEW_SERVER);
+	pkt.server.service = cpu_to_le32(svc->service);
+	pkt.server.instance = cpu_to_le32(svc->version | svc->instance << 8);
+	pkt.server.node = qmi->sq.sq_node;
+	pkt.server.port = qmi->sq.sq_port;
+
+	sq.sq_family = qmi->sq.sq_family;
+	sq.sq_node = qmi->sq.sq_node;
+	sq.sq_port = QRTR_PORT_CTRL;
+
+	msg.msg_name = &sq;
+	msg.msg_namelen = sizeof(sq);
+
+	mutex_lock(&qmi->sock_lock);
+	if (qmi->sock) {
+		ret = kernel_sendmsg(qmi->sock, &msg, &iv, 1, sizeof(pkt));
+		if (ret < 0)
+			pr_err("failed to send service registration: %d\n", ret);
+	}
+	mutex_unlock(&qmi->sock_lock);
+}
+
+/**
+ * qmi_add_server() - register a service with the name service
+ * @qmi:	qmi handle
+ * @service:	type of the service
+ * @instance:	instance of the service
+ *
+ * Returns 0 on success, negative errno on failure.
+ *
+ * Register a new service with the name service. This allows clients to find
+ * and start sending messages to the client associated with @qmi.
+ */
+int qmi_add_server(struct qmi_handle *qmi, unsigned int service,
+		   unsigned int version, unsigned int instance)
+{
+	struct qmi_service *svc;
+
+	svc = kzalloc(sizeof(*svc), GFP_KERNEL);
+	if (!svc)
+		return -ENOMEM;
+
+	svc->service = service;
+	svc->version = version;
+	svc->instance = instance;
+
+	list_add(&svc->list_node, &qmi->services);
+
+	qmi_send_new_server(qmi, svc);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(qmi_add_server);
+
+/**
+ * qmi_txn_init() - allocate transaction id within the given QMI handle
+ * @qmi:	QMI handle
+ * @txn:	transaction context
+ * @ei:		description of how to decode a matching response (optional)
+ * @c_struct:	pointer to the object to decode the response into (optional)
+ *
+ * Returns transaction id on success, negative errno on failure.
+ *
+ * This allocates a transaction id within the QMI handle. If @ei and @c_struct
+ * are specified any responses to this transaction will be decoded as described
+ * by @ei into @c_struct.
+ *
+ * A client calling qmi_txn_init() must call either qmi_txn_wait() or
+ * qmi_txn_cancel() to free up the allocated resources.
+ */
+int qmi_txn_init(struct qmi_handle *qmi, struct qmi_txn *txn,
+		 struct qmi_elem_info *ei, void *c_struct)
+{
+	int ret;
+
+	memset(txn, 0, sizeof(*txn));
+
+	mutex_init(&txn->lock);
+	init_completion(&txn->completion);
+	txn->qmi = qmi;
+	txn->ei = ei;
+	txn->dest = c_struct;
+
+	mutex_lock(&qmi->txn_lock);
+	ret = idr_alloc_cyclic(&qmi->txns, txn, 0, INT_MAX, GFP_KERNEL);
+	if (ret < 0)
+		pr_err("failed to allocate transaction id\n");
+
+	txn->id = ret;
+	mutex_unlock(&qmi->txn_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(qmi_txn_init);
+
+/**
+ * qmi_txn_wait() - wait for a response on a transaction
+ * @txn:	transaction handle
+ * @timeout:	timeout, in jiffies
+ *
+ * Returns the transaction response on success, negative errno on failure.
+ *
+ * If the transaction is decoded by the means of @ei and @c_struct the return
+ * value will be the returned value of qmi_decode_message(), otherwise it's up
+ * to the specified message handler to fill out the result.
+ */
+int qmi_txn_wait(struct qmi_txn *txn, unsigned long timeout)
+{
+	struct qmi_handle *qmi = txn->qmi;
+	int ret;
+
+	ret = wait_for_completion_interruptible_timeout(&txn->completion,
+							timeout);
+
+	mutex_lock(&qmi->txn_lock);
+	mutex_lock(&txn->lock);
+	idr_remove(&qmi->txns, txn->id);
+	mutex_unlock(&txn->lock);
+	mutex_unlock(&qmi->txn_lock);
+
+	if (ret < 0)
+		return ret;
+	else if (ret == 0)
+		return -ETIMEDOUT;
+	else
+		return txn->result;
+}
+EXPORT_SYMBOL_GPL(qmi_txn_wait);
+
+/**
+ * qmi_txn_cancel() - cancel an ongoing transaction
+ * @txn:	transaction id
+ */
+void qmi_txn_cancel(struct qmi_txn *txn)
+{
+	struct qmi_handle *qmi = txn->qmi;
+
+	mutex_lock(&qmi->txn_lock);
+	mutex_lock(&txn->lock);
+	idr_remove(&qmi->txns, txn->id);
+	mutex_unlock(&txn->lock);
+	mutex_unlock(&qmi->txn_lock);
+}
+EXPORT_SYMBOL_GPL(qmi_txn_cancel);
+
+/**
+ * qmi_invoke_handler() - find and invoke a handler for a message
+ * @qmi:	qmi handle
+ * @sq:		sockaddr of the sender
+ * @txn:	transaction object for the message
+ * @buf:	buffer containing the message
+ * @len:	length of @buf
+ *
+ * Find handler and invoke handler for the incoming message.
+ */
+static void qmi_invoke_handler(struct qmi_handle *qmi, struct sockaddr_qrtr *sq,
+			       struct qmi_txn *txn, const void *buf, size_t len)
+{
+	struct qmi_msg_handler *handler;
+	const struct qmi_header *hdr = buf;
+	void *dest;
+	int ret;
+
+	if (!qmi->handlers)
+		return;
+
+	for (handler = qmi->handlers; handler->fn; handler++) {
+		if (handler->type == hdr->type &&
+		    handler->msg_id == hdr->msg_id)
+			break;
+	}
+
+	if (!handler->fn)
+		return;
+
+	dest = kzalloc(handler->decoded_size, GFP_KERNEL);
+	if (!dest)
+		return;
+
+	ret = qmi_decode_message(buf, len, handler->ei, dest);
+	if (ret < 0)
+		pr_err("failed to decode incoming message\n");
+	else
+		handler->fn(qmi, sq, txn, dest);
+
+	kfree(dest);
+}
+
+/**
+ * qmi_handle_net_reset() - invoked to handle ENETRESET on a QMI handle
+ * @qmi:	the QMI context
+ *
+ * As a result of registering a name service with the QRTR all open sockets are
+ * flagged with ENETRESET and this function will be called. The typical case is
+ * the initial boot, where this signals that the local node id has been
+ * configured and as such any bound sockets needs to be rebound. So close the
+ * socket, inform the client and re-initialize the socket.
+ *
+ * For clients it's generally sufficient to react to the del_server callbacks,
+ * but server code is expected to treat the net_reset callback as a "bye" from
+ * all nodes.
+ *
+ * Finally the QMI handle will send out registration requests for any lookups
+ * and services.
+ */
+static void qmi_handle_net_reset(struct qmi_handle *qmi)
+{
+	struct sockaddr_qrtr sq;
+	struct qmi_service *svc;
+	struct socket *sock;
+
+	sock = qmi_sock_create(qmi, &sq);
+	if (IS_ERR(sock))
+		return;
+
+	mutex_lock(&qmi->sock_lock);
+	sock_release(qmi->sock);
+	qmi->sock = NULL;
+	mutex_unlock(&qmi->sock_lock);
+
+	qmi_recv_del_server(qmi, -1, -1);
+
+	if (qmi->ops.net_reset)
+		qmi->ops.net_reset(qmi);
+
+	mutex_lock(&qmi->sock_lock);
+	qmi->sock = sock;
+	qmi->sq = sq;
+	mutex_unlock(&qmi->sock_lock);
+
+	list_for_each_entry(svc, &qmi->lookups, list_node)
+		qmi_send_new_lookup(qmi, svc);
+
+	list_for_each_entry(svc, &qmi->services, list_node)
+		qmi_send_new_server(qmi, svc);
+}
+
+static void qmi_handle_message(struct qmi_handle *qmi,
+			       struct sockaddr_qrtr *sq,
+			       const void *buf, size_t len)
+{
+	const struct qmi_header *hdr;
+	struct qmi_txn tmp_txn;
+	struct qmi_txn *txn = NULL;
+	int ret;
+
+	if (len < sizeof(*hdr)) {
+		pr_err("ignoring short QMI packet\n");
+		return;
+	}
+
+	hdr = buf;
+
+	/* If this is a response, find the matching transaction handle */
+	if (hdr->type == QMI_RESPONSE) {
+		mutex_lock(&qmi->txn_lock);
+		txn = idr_find(&qmi->txns, hdr->txn_id);
+		if (txn)
+			mutex_lock(&txn->lock);
+		mutex_unlock(&qmi->txn_lock);
+	}
+
+	if (txn && txn->dest && txn->ei) {
+		ret = qmi_decode_message(buf, len, txn->ei, txn->dest);
+		if (ret < 0)
+			pr_err("failed to decode incoming message\n");
+
+		txn->result = ret;
+		complete(&txn->completion);
+
+		mutex_unlock(&txn->lock);
+	} else if (txn) {
+		qmi_invoke_handler(qmi, sq, txn, buf, len);
+
+		mutex_unlock(&txn->lock);
+	} else {
+		/* Create a txn based on the txn_id of the incoming message */
+		memset(&tmp_txn, 0, sizeof(tmp_txn));
+		tmp_txn.id = hdr->txn_id;
+
+		qmi_invoke_handler(qmi, sq, &tmp_txn, buf, len);
+	}
+}
+
+static void qmi_data_ready_work(struct work_struct *work)
+{
+	struct qmi_handle *qmi = container_of(work, struct qmi_handle, work);
+	struct qmi_ops *ops = &qmi->ops;
+	struct sockaddr_qrtr sq;
+	struct msghdr msg = { .msg_name = &sq, .msg_namelen = sizeof(sq) };
+	struct kvec iv;
+	ssize_t msglen;
+
+	for (;;) {
+		iv.iov_base = qmi->recv_buf;
+		iv.iov_len = qmi->recv_buf_size;
+
+		mutex_lock(&qmi->sock_lock);
+		if (qmi->sock)
+			msglen = kernel_recvmsg(qmi->sock, &msg, &iv, 1,
+						iv.iov_len, MSG_DONTWAIT);
+		else
+			msglen = -EPIPE;
+		mutex_unlock(&qmi->sock_lock);
+		if (msglen == -EAGAIN)
+			break;
+
+		if (msglen == -ENETRESET) {
+			qmi_handle_net_reset(qmi);
+
+			/* The old qmi->sock is gone, our work is done */
+			break;
+		}
+
+		if (msglen < 0) {
+			pr_err("qmi recvmsg failed: %zd\n", msglen);
+			break;
+		}
+
+		if (sq.sq_node == qmi->sq.sq_node &&
+		    sq.sq_port == QRTR_PORT_CTRL) {
+			qmi_recv_ctrl_pkt(qmi, qmi->recv_buf, msglen);
+		} else if (ops->msg_handler) {
+			ops->msg_handler(qmi, &sq, qmi->recv_buf, msglen);
+		} else {
+			qmi_handle_message(qmi, &sq, qmi->recv_buf, msglen);
+		}
+	}
+}
+
+static void qmi_data_ready(struct sock *sk)
+{
+	struct qmi_handle *qmi = sk->sk_user_data;
+
+	/*
+	 * This will be NULL if we receive data while being in
+	 * qmi_handle_release()
+	 */
+	if (!qmi)
+		return;
+
+	queue_work(qmi->wq, &qmi->work);
+}
+
+static struct socket *qmi_sock_create(struct qmi_handle *qmi,
+				      struct sockaddr_qrtr *sq)
+{
+	struct socket *sock;
+	int sl = sizeof(*sq);
+	int ret;
+
+	ret = sock_create_kern(&init_net, AF_QIPCRTR, SOCK_DGRAM,
+			       PF_QIPCRTR, &sock);
+	if (ret < 0)
+		return ERR_PTR(ret);
+
+	ret = kernel_getsockname(sock, (struct sockaddr *)sq, &sl);
+	if (ret < 0) {
+		sock_release(sock);
+		return ERR_PTR(ret);
+	}
+
+	sock->sk->sk_user_data = qmi;
+	sock->sk->sk_data_ready = qmi_data_ready;
+	sock->sk->sk_error_report = qmi_data_ready;
+
+	return sock;
+}
+
+/**
+ * qmi_handle_init() - initialize a QMI client handle
+ * @qmi:	QMI handle to initialize
+ * @max_msg_len: maximum size of incoming message
+ * @handlers:	NULL-terminated list of QMI message handlers
+ *
+ * Returns 0 on success, negative errno on failure.
+ *
+ * This initializes the QMI client handle to allow sending and receiving QMI
+ * messages. As messages are received the appropriate handler will be invoked.
+ */
+int qmi_handle_init(struct qmi_handle *qmi, size_t recv_buf_size,
+		    struct qmi_ops *ops, struct qmi_msg_handler *handlers)
+{
+	int ret;
+
+	mutex_init(&qmi->txn_lock);
+	mutex_init(&qmi->sock_lock);
+
+	idr_init(&qmi->txns);
+
+	INIT_LIST_HEAD(&qmi->lookups);
+	INIT_LIST_HEAD(&qmi->lookup_results);
+	INIT_LIST_HEAD(&qmi->services);
+
+	INIT_WORK(&qmi->work, qmi_data_ready_work);
+
+	qmi->handlers = handlers;
+	if (ops)
+		qmi->ops = *ops;
+
+	if (recv_buf_size < sizeof(struct qrtr_ctrl_pkt))
+		recv_buf_size = sizeof(struct qrtr_ctrl_pkt);
+	else
+		recv_buf_size += sizeof(struct qmi_header);
+
+	qmi->recv_buf_size = recv_buf_size;
+	qmi->recv_buf = kzalloc(recv_buf_size, GFP_KERNEL);
+	if (!qmi->recv_buf)
+		return -ENOMEM;
+
+	qmi->wq = alloc_workqueue("qmi_msg_handler", WQ_UNBOUND, 1);
+	if (!qmi->wq) {
+		ret = -ENOMEM;
+		goto err_free_recv_buf;
+	}
+
+	qmi->sock = qmi_sock_create(qmi, &qmi->sq);
+	if (IS_ERR(qmi->sock)) {
+		pr_err("failed to create QMI socket\n");
+		ret = PTR_ERR(qmi->sock);
+		goto err_destroy_wq;
+	}
+
+	return 0;
+
+err_destroy_wq:
+	destroy_workqueue(qmi->wq);
+err_free_recv_buf:
+	kfree(qmi->recv_buf);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(qmi_handle_init);
+
+/**
+ * qmi_handle_release() - release the QMI client handle
+ * @qmi:	QMI client handle
+ *
+ * This closes the underlying socket and stops any handling of QMI messages.
+ */
+void qmi_handle_release(struct qmi_handle *qmi)
+{
+	struct socket *sock = qmi->sock;
+	struct qmi_service *svc, *tmp;
+
+	sock->sk->sk_user_data = NULL;
+	cancel_work_sync(&qmi->work);
+
+	qmi_recv_del_server(qmi, -1, -1);
+
+	mutex_lock(&qmi->sock_lock);
+	sock_release(sock);
+	qmi->sock = NULL;
+	mutex_unlock(&qmi->sock_lock);
+
+	destroy_workqueue(qmi->wq);
+
+	idr_destroy(&qmi->txns);
+
+	kfree(qmi->recv_buf);
+
+	/* Free registered lookup requests */
+	list_for_each_entry_safe(svc, tmp, &qmi->lookups, list_node) {
+		list_del(&svc->list_node);
+		kfree(svc);
+	}
+
+	/* Free registered service information */
+	list_for_each_entry_safe(svc, tmp, &qmi->services, list_node) {
+		list_del(&svc->list_node);
+		kfree(svc);
+	}
+}
+EXPORT_SYMBOL_GPL(qmi_handle_release);
+
+/**
+ * qmi_send_message() - send a QMI message
+ * @qmi:	QMI client handle
+ * @sq:		destination sockaddr
+ * @txn:	transaction object to use for the message
+ * @type:	type of message to send
+ * @msg_id:	message id
+ * @len:	max length of the QMI message
+ * @ei:		QMI message description
+ * @c_struct:	object to be encoded
+ *
+ * Returns 0 on success, negative errno on failure.
+ *
+ * This function encodes @c_struct using @ei into a message of type @type,
+ * with @msg_id and @txn into a buffer of maximum size @len, and sends this to
+ * @sq.
+ */
+static ssize_t qmi_send_message(struct qmi_handle *qmi,
+				struct sockaddr_qrtr *sq, struct qmi_txn *txn,
+				int type, int msg_id, size_t len,
+				struct qmi_elem_info *ei, const void *c_struct)
+{
+	struct msghdr msghdr = {0};
+	struct kvec iv;
+	void *msg;
+	int ret;
+
+	msg = qmi_encode_message(type,
+				 msg_id, &len,
+				 txn->id, ei,
+				 c_struct);
+	if (IS_ERR(msg))
+		return PTR_ERR(msg);
+
+	iv.iov_base = msg;
+	iv.iov_len = len;
+
+	if (sq) {
+		msghdr.msg_name = sq;
+		msghdr.msg_namelen = sizeof(*sq);
+	}
+
+	mutex_lock(&qmi->sock_lock);
+	if (qmi->sock) {
+		ret = kernel_sendmsg(qmi->sock, &msghdr, &iv, 1, len);
+		if (ret < 0)
+			pr_err("failed to send QMI message\n");
+	} else {
+		ret = -EPIPE;
+	}
+	mutex_unlock(&qmi->sock_lock);
+
+	kfree(msg);
+
+	return ret < 0 ? ret : 0;
+}
+
+/**
+ * qmi_send_indication() - send a request QMI message
+ * @qmi:	QMI client handle
+ * @sq:		destination sockaddr
+ * @txn:	transaction object to use for the message
+ * @msg_id:	message id
+ * @len:	max length of the QMI message
+ * @ei:		QMI message description
+ * @c_struct:	object to be encoded
+ *
+ * Returns 0 on success, negative errno on failure.
+ */
+ssize_t qmi_send_request(struct qmi_handle *qmi, struct sockaddr_qrtr *sq,
+			 struct qmi_txn *txn, int msg_id, size_t len,
+			 struct qmi_elem_info *ei, const void *c_struct)
+{
+	return qmi_send_message(qmi, sq, txn, QMI_REQUEST, msg_id, len, ei,
+				c_struct);
+}
+EXPORT_SYMBOL_GPL(qmi_send_request);
+
+/**
+ * qmi_send_indication() - send a response QMI message
+ * @qmi:	QMI client handle
+ * @sq:		destination sockaddr
+ * @txn:	transaction object to use for the message
+ * @msg_id:	message id
+ * @len:	max length of the QMI message
+ * @ei:		QMI message description
+ * @c_struct:	object to be encoded
+ *
+ * Returns 0 on success, negative errno on failure.
+ */
+ssize_t qmi_send_response(struct qmi_handle *qmi, struct sockaddr_qrtr *sq,
+			  struct qmi_txn *txn, int msg_id, size_t len,
+			  struct qmi_elem_info *ei, const void *c_struct)
+{
+	return qmi_send_message(qmi, sq, txn, QMI_RESPONSE, msg_id, len, ei,
+				c_struct);
+}
+EXPORT_SYMBOL_GPL(qmi_send_response);
+
+/**
+ * qmi_send_indication() - send an indication QMI message
+ * @qmi:	QMI client handle
+ * @sq:		destination sockaddr
+ * @txn:	transaction object to use for the message
+ * @msg_id:	message id
+ * @len:	max length of the QMI message
+ * @ei:		QMI message description
+ * @c_struct:	object to be encoded
+ *
+ * Returns 0 on success, negative errno on failure.
+ */
+ssize_t qmi_send_indication(struct qmi_handle *qmi, struct sockaddr_qrtr *sq,
+			    int msg_id, size_t len, struct qmi_elem_info *ei,
+			    const void *c_struct)
+{
+	struct qmi_txn txn;
+	ssize_t rval;
+	int ret;
+
+	ret = qmi_txn_init(qmi, &txn, NULL, NULL);
+	if (ret < 0)
+		return ret;;
+
+	rval = qmi_send_message(qmi, sq, &txn, QMI_INDICATION, msg_id, len, ei,
+				c_struct);
+
+	/* We don't care about future messages on this txn */
+	qmi_txn_cancel(&txn);
+
+	return rval;
+}
+EXPORT_SYMBOL_GPL(qmi_send_indication);
diff --git a/include/linux/soc/qcom/qmi.h b/include/linux/soc/qcom/qmi.h
index 804d2232c55b..1aedc8f14ec2 100644
--- a/include/linux/soc/qcom/qmi.h
+++ b/include/linux/soc/qcom/qmi.h
@@ -105,6 +105,159 @@ struct qmi_response_type_v01 {
 
 extern struct qmi_elem_info qmi_response_type_v01_ei[];
 
+/**
+ * struct qmi_service - context to track lookup-results
+ * @service:	service type
+ * @version:	version of the @service
+ * @instance:	instance id of the @service
+ * @node:	node of the service
+ * @port:	port of the service
+ * @priv:	handle for client's use
+ * @list_node:	list_head for house keeping
+ */
+struct qmi_service {
+	unsigned int service;
+	unsigned int version;
+	unsigned int instance;
+
+	unsigned int node;
+	unsigned int port;
+
+	void *priv;
+	struct list_head list_node;
+};
+
+struct qmi_handle;
+
+/**
+ * struct qmi_ops - callbacks for qmi_handle
+ * @new_server:		inform client of a new_server lookup-result, returning
+ *                      successfully from this call causes the library to call
+ *                      @del_server as the service is removed from the
+ *                      lookup-result. @priv of the qmi_service can be used by
+ *                      the client
+ * @del_server:		inform client of a del_server lookup-result
+ * @net_reset:		inform client that the name service was restarted and
+ *                      that and any state needs to be released
+ * @msg_handler:	invoked for incoming messages, allows a client to
+ *                      override the usual QMI message handler
+ * @bye:                inform a client that all clients from a node are gone
+ * @del_client:         inform a client that a particular client is gone
+ */
+struct qmi_ops {
+	int (*new_server)(struct qmi_handle *qmi, struct qmi_service *svc);
+	void (*del_server)(struct qmi_handle *qmi, struct qmi_service *svc);
+	void (*net_reset)(struct qmi_handle *qmi);
+	void (*msg_handler)(struct qmi_handle *qmi, struct sockaddr_qrtr *sq,
+			    const void *data, size_t count);
+	void (*bye)(struct qmi_handle *qmi, unsigned int node);
+	void (*del_client)(struct qmi_handle *qmi,
+			   unsigned int node, unsigned int port);
+};
+
+
+/**
+ * struct qmi_txn - transaction context
+ * @qmi:	QMI handle this transaction is associated with
+ * @id:		transaction id
+ * @lock:	for synchronization between handler and waiter of messages
+ * @completion:	completion object as the transaction receives a response
+ * @result:	result code for the completed transaction
+ * @ei:		description of the QMI encoded response (optional)
+ * @dest:	destination buffer to decode message into (optional)
+ */
+struct qmi_txn {
+	struct qmi_handle *qmi;
+
+	int id;
+
+	struct mutex lock;
+	struct completion completion;
+	int result;
+
+	struct qmi_elem_info *ei;
+	void *dest;
+};
+
+/**
+ * struct qmi_msg_handler - description of QMI message handler
+ * @type:	type of message
+ * @msg_id:	message id
+ * @ei:		description of the QMI encoded message
+ * @decoded_size:	size of the decoded object
+ * @fn:		function to invoke as the message is decoded
+ */
+struct qmi_msg_handler {
+	unsigned int type;
+	unsigned int msg_id;
+
+	struct qmi_elem_info *ei;
+
+	size_t decoded_size;
+	void (*fn)(struct qmi_handle *qmi, struct sockaddr_qrtr *sq,
+		   struct qmi_txn *txn, const void *decoded);
+};
+
+/**
+ * struct qmi_handle - QMI context
+ * @sock:	socket handle
+ * @sock_lock:	synchronization of @sock modifications
+ * @sq:		sockaddr of @sock
+ * @work:	work for handling incoming messages
+ * @wq:		workqueue to post @work on
+ * @recv_buf:	scratch buffer for handling incoming messages
+ * @recv_buf_size:	size of @recv_buf
+ * @lookups:		list of registered lookup requests
+ * @lookup_results:	list of lookup-results advertised to the client
+ * @services:		list of registered services (by this client)
+ * @ops:	reference to callbacks
+ * @txns:	outstanding transactions
+ * @txn_lock:	lock for modifications of @txns
+ * @handlers:	list of handlers for incoming messages
+ */
+struct qmi_handle {
+	struct socket *sock;
+	struct mutex sock_lock;
+
+	struct sockaddr_qrtr sq;
+
+	struct work_struct work;
+	struct workqueue_struct *wq;
+
+	void *recv_buf;
+	size_t recv_buf_size;
+
+	struct list_head lookups;
+	struct list_head lookup_results;
+	struct list_head services;
+
+	struct qmi_ops ops;
+
+	struct idr txns;
+	struct mutex txn_lock;
+
+	struct qmi_msg_handler *handlers;
+};
+
+int qmi_add_lookup(struct qmi_handle *qmi, unsigned int service,
+		   unsigned int version, unsigned int instance);
+int qmi_add_server(struct qmi_handle *qmi, unsigned int service,
+		   unsigned int version, unsigned int instance);
+
+int qmi_handle_init(struct qmi_handle *qmi, size_t max_msg_len,
+		    struct qmi_ops *ops, struct qmi_msg_handler *handlers);
+void qmi_handle_release(struct qmi_handle *qmi);
+
+ssize_t qmi_send_request(struct qmi_handle *qmi, struct sockaddr_qrtr *sq,
+			 struct qmi_txn *txn, int msg_id, size_t len,
+			 struct qmi_elem_info *ei, const void *c_struct);
+ssize_t qmi_send_response(struct qmi_handle *qmi, struct sockaddr_qrtr *sq,
+			  struct qmi_txn *txn, int msg_id, size_t len,
+			  struct qmi_elem_info *ei, const void *c_struct);
+ssize_t qmi_send_indication(struct qmi_handle *qmi, struct sockaddr_qrtr *sq,
+			    int msg_id, size_t len, struct qmi_elem_info *ei,
+			    const void *c_struct);
+
 void *qmi_encode_message(int type, unsigned int msg_id, size_t *len,
 			 unsigned int txn_id, struct qmi_elem_info *ei,
 			 const void *c_struct);
@@ -112,5 +265,9 @@ void *qmi_encode_message(int type, unsigned int msg_id, size_t *len,
 int qmi_decode_message(const void *buf, size_t len,
 		       struct qmi_elem_info *ei, void *c_struct);
 
+int qmi_txn_init(struct qmi_handle *qmi, struct qmi_txn *txn,
+		 struct qmi_elem_info *ei, void *c_struct);
+int qmi_txn_wait(struct qmi_txn *txn, unsigned long timeout);
+void qmi_txn_cancel(struct qmi_txn *txn);
 
 #endif
-- 
2.15.0

[PATCH v2 3/5] remoteproc: Pass type of shutdown to subdev remove

[Bjorn Andersson]

remoteproc instances can be stopped either by invoking shutdown or by an
attempt to recover from a crash. For some subdev types it's expected to
clean up gracefully during a shutdown, but are unable to do so during a
crash - so pass this information to the subdev remove functions.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
---

Changes since v1:
- New patch

 drivers/remoteproc/qcom_common.c     |  6 +++---
 drivers/remoteproc/remoteproc_core.c | 18 +++++++++---------
 include/linux/remoteproc.h           |  4 ++--
 3 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/drivers/remoteproc/qcom_common.c b/drivers/remoteproc/qcom_common.c
index d487040b528b..7a862d41503e 100644
--- a/drivers/remoteproc/qcom_common.c
+++ b/drivers/remoteproc/qcom_common.c
@@ -60,7 +60,7 @@ static int glink_subdev_probe(struct rproc_subdev *subdev)
 	return IS_ERR(glink->edge) ? PTR_ERR(glink->edge) : 0;
 }
 
-static void glink_subdev_remove(struct rproc_subdev *subdev)
+static void glink_subdev_remove(struct rproc_subdev *subdev, bool graceful)
 {
 	struct qcom_rproc_glink *glink = to_glink_subdev(subdev);
 
@@ -107,7 +107,7 @@ static int smd_subdev_probe(struct rproc_subdev *subdev)
 	return PTR_ERR_OR_ZERO(smd->edge);
 }
 
-static void smd_subdev_remove(struct rproc_subdev *subdev)
+static void smd_subdev_remove(struct rproc_subdev *subdev, bool graceful)
 {
 	struct qcom_rproc_subdev *smd = to_smd_subdev(subdev);
 
@@ -176,7 +176,7 @@ static int ssr_notify_start(struct rproc_subdev *subdev)
 	return  0;
 }
 
-static void ssr_notify_stop(struct rproc_subdev *subdev)
+static void ssr_notify_stop(struct rproc_subdev *subdev, bool graceful)
 {
 	struct qcom_rproc_ssr *ssr = to_ssr_subdev(subdev);
 
diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index eab14b414bf0..3146e965ca47 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -307,7 +307,7 @@ static int rproc_vdev_do_probe(struct rproc_subdev *subdev)
 	return rproc_add_virtio_dev(rvdev, rvdev->id);
 }
 
-static void rproc_vdev_do_remove(struct rproc_subdev *subdev)
+static void rproc_vdev_do_remove(struct rproc_subdev *subdev, bool graceful)
 {
 	struct rproc_vdev *rvdev = container_of(subdev, struct rproc_vdev, subdev);
 
@@ -785,17 +785,17 @@ static int rproc_probe_subdevices(struct rproc *rproc)
 
 unroll_registration:
 	list_for_each_entry_continue_reverse(subdev, &rproc->subdevs, node)
-		subdev->remove(subdev);
+		subdev->remove(subdev, false);
 
 	return ret;
 }
 
-static void rproc_remove_subdevices(struct rproc *rproc)
+static void rproc_remove_subdevices(struct rproc *rproc, bool graceful)
 {
 	struct rproc_subdev *subdev;
 
 	list_for_each_entry_reverse(subdev, &rproc->subdevs, node)
-		subdev->remove(subdev);
+		subdev->remove(subdev, graceful);
 }
 
 /**
@@ -1013,13 +1013,13 @@ static int rproc_trigger_auto_boot(struct rproc *rproc)
 	return ret;
 }
 
-static int rproc_stop(struct rproc *rproc)
+static int rproc_stop(struct rproc *rproc, bool graceful)
 {
 	struct device *dev = &rproc->dev;
 	int ret;
 
 	/* remove any subdevices for the remote processor */
-	rproc_remove_subdevices(rproc);
+	rproc_remove_subdevices(rproc, graceful);
 
 	/* power off the remote processor */
 	ret = rproc->ops->stop(rproc);
@@ -1063,7 +1063,7 @@ int rproc_trigger_recovery(struct rproc *rproc)
 	if (ret)
 		return ret;
 
-	ret = rproc_stop(rproc);
+	ret = rproc_stop(rproc, false);
 	if (ret)
 		goto unlock_mutex;
 
@@ -1216,7 +1216,7 @@ void rproc_shutdown(struct rproc *rproc)
 	if (!atomic_dec_and_test(&rproc->power))
 		goto out;
 
-	ret = rproc_stop(rproc);
+	ret = rproc_stop(rproc, true);
 	if (ret) {
 		atomic_inc(&rproc->power);
 		goto out;
@@ -1550,7 +1550,7 @@ EXPORT_SYMBOL(rproc_del);
 void rproc_add_subdev(struct rproc *rproc,
 		      struct rproc_subdev *subdev,
 		      int (*probe)(struct rproc_subdev *subdev),
-		      void (*remove)(struct rproc_subdev *subdev))
+		      void (*remove)(struct rproc_subdev *subdev, bool graceful))
 {
 	subdev->probe = probe;
 	subdev->remove = remove;
diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
index 44e630eb3d94..20a9467744ea 100644
--- a/include/linux/remoteproc.h
+++ b/include/linux/remoteproc.h
@@ -456,7 +456,7 @@ struct rproc_subdev {
 	struct list_head node;
 
 	int (*probe)(struct rproc_subdev *subdev);
-	void (*remove)(struct rproc_subdev *subdev);
+	void (*remove)(struct rproc_subdev *subdev, bool graceful);
 };
 
 /* we currently support only two vrings per rvdev */
@@ -539,7 +539,7 @@ static inline struct rproc *vdev_to_rproc(struct virtio_device *vdev)
 void rproc_add_subdev(struct rproc *rproc,
 		      struct rproc_subdev *subdev,
 		      int (*probe)(struct rproc_subdev *subdev),
-		      void (*remove)(struct rproc_subdev *subdev));
+		      void (*remove)(struct rproc_subdev *subdev, bool graceful));
 
 void rproc_remove_subdev(struct rproc *rproc, struct rproc_subdev *subdev);
 
-- 
2.15.0

[PATCH v2 4/5] remoteproc: qcom: Introduce sysmon

[Bjorn Andersson]

The sysmon client communicates either via a dedicated SMD/GLINK channel
or via QMI encoded messages over IPCROUTER with remote processors in
order to perform graceful shutdown and inform about other remote
processors shutting down.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
---

Changes since v1:
- New patch

 drivers/remoteproc/Kconfig         |  17 ++
 drivers/remoteproc/Makefile        |   1 +
 drivers/remoteproc/qcom_adsp_pil.c |  12 +
 drivers/remoteproc/qcom_common.h   |  21 ++
 drivers/remoteproc/qcom_q6v5_pil.c |   3 +
 drivers/remoteproc/qcom_sysmon.c   | 585 +++++++++++++++++++++++++++++++++++++
 drivers/remoteproc/qcom_wcnss.c    |   4 +
 7 files changed, 643 insertions(+)
 create mode 100644 drivers/remoteproc/qcom_sysmon.c

diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig
index df63e44526ac..41a6c0b90e2c 100644
--- a/drivers/remoteproc/Kconfig
+++ b/drivers/remoteproc/Kconfig
@@ -93,6 +93,7 @@ config QCOM_ADSP_PIL
 	depends on QCOM_SMEM
 	depends on RPMSG_QCOM_SMD || (COMPILE_TEST && RPMSG_QCOM_SMD=n)
 	depends on RPMSG_QCOM_GLINK_SMEM || RPMSG_QCOM_GLINK_SMEM=n
+	depends on QCOM_SYSMON || QCOM_SYSMON=n
 	select MFD_SYSCON
 	select QCOM_MDT_LOADER
 	select QCOM_RPROC_COMMON
@@ -109,6 +110,7 @@ config QCOM_Q6V5_PIL
 	depends on OF && ARCH_QCOM
 	depends on QCOM_SMEM
 	depends on RPMSG_QCOM_SMD || (COMPILE_TEST && RPMSG_QCOM_SMD=n)
+	depends on QCOM_SYSMON || QCOM_SYSMON=n
 	select MFD_SYSCON
 	select QCOM_RPROC_COMMON
 	select QCOM_SCM
@@ -116,11 +118,26 @@ config QCOM_Q6V5_PIL
 	  Say y here to support the Qualcomm Peripherial Image Loader for the
 	  Hexagon V5 based remote processors.
 
+config QCOM_SYSMON
+	tristate "Qualcomm sysmon driver"
+	depends on RPMSG
+	depends on ARCH_QCOM
+	select QCOM_QMI_HELPERS
+	help
+	  The sysmon driver implements a sysmon QMI client and a handler for
+	  the sys_mon SMD and GLINK channel, which are used for graceful
+	  shutdown, retrieving failure information and propagating information
+	  about other subsystems being shut down.
+
+	  Say y here if your system runs firmware on any other subsystems, e.g.
+	  modem or DSP.
+
 config QCOM_WCNSS_PIL
 	tristate "Qualcomm WCNSS Peripheral Image Loader"
 	depends on OF && ARCH_QCOM
 	depends on RPMSG_QCOM_SMD || (COMPILE_TEST && RPMSG_QCOM_SMD=n)
 	depends on QCOM_SMEM
+	depends on QCOM_SYSMON || QCOM_SYSMON=n
 	select QCOM_MDT_LOADER
 	select QCOM_RPROC_COMMON
 	select QCOM_SCM
diff --git a/drivers/remoteproc/Makefile b/drivers/remoteproc/Makefile
index 1a0b3dd44b8c..6ca1014154ef 100644
--- a/drivers/remoteproc/Makefile
+++ b/drivers/remoteproc/Makefile
@@ -16,6 +16,7 @@ obj-$(CONFIG_KEYSTONE_REMOTEPROC)	+= keystone_remoteproc.o
 obj-$(CONFIG_QCOM_ADSP_PIL)		+= qcom_adsp_pil.o
 obj-$(CONFIG_QCOM_RPROC_COMMON)		+= qcom_common.o
 obj-$(CONFIG_QCOM_Q6V5_PIL)		+= qcom_q6v5_pil.o
+obj-$(CONFIG_QCOM_SYSMON)		+= qcom_sysmon.o
 obj-$(CONFIG_QCOM_WCNSS_PIL)		+= qcom_wcnss_pil.o
 qcom_wcnss_pil-y			+= qcom_wcnss.o
 qcom_wcnss_pil-y			+= qcom_wcnss_iris.o
diff --git a/drivers/remoteproc/qcom_adsp_pil.c b/drivers/remoteproc/qcom_adsp_pil.c
index 3f6af54dbc96..45e7e66604d4 100644
--- a/drivers/remoteproc/qcom_adsp_pil.c
+++ b/drivers/remoteproc/qcom_adsp_pil.c
@@ -38,7 +38,10 @@ struct adsp_data {
 	const char *firmware_name;
 	int pas_id;
 	bool has_aggre2_clk;
+
 	const char *ssr_name;
+	const char *sysmon_name;
+	int ssctl_id;
 };
 
 struct qcom_adsp {
@@ -75,6 +78,7 @@ struct qcom_adsp {
 	struct qcom_rproc_glink glink_subdev;
 	struct qcom_rproc_subdev smd_subdev;
 	struct qcom_rproc_ssr ssr_subdev;
+	struct qcom_sysmon *sysmon;
 };
 
 static int adsp_load(struct rproc *rproc, const struct firmware *fw)
@@ -404,6 +408,9 @@ static int adsp_probe(struct platform_device *pdev)
 	qcom_add_glink_subdev(rproc, &adsp->glink_subdev);
 	qcom_add_smd_subdev(rproc, &adsp->smd_subdev);
 	qcom_add_ssr_subdev(rproc, &adsp->ssr_subdev, desc->ssr_name);
+	adsp->sysmon = qcom_add_sysmon_subdev(rproc,
+					      desc->sysmon_name,
+					      desc->ssctl_id);
 
 	ret = rproc_add(rproc);
 	if (ret)
@@ -425,6 +432,7 @@ static int adsp_remove(struct platform_device *pdev)
 	rproc_del(adsp->rproc);
 
 	qcom_remove_glink_subdev(adsp->rproc, &adsp->glink_subdev);
+	qcom_remove_sysmon_subdev(adsp->sysmon);
 	qcom_remove_smd_subdev(adsp->rproc, &adsp->smd_subdev);
 	qcom_remove_ssr_subdev(adsp->rproc, &adsp->ssr_subdev);
 	rproc_free(adsp->rproc);
@@ -438,6 +446,8 @@ static const struct adsp_data adsp_resource_init = {
 		.pas_id = 1,
 		.has_aggre2_clk = false,
 		.ssr_name = "lpass",
+		.sysmon_name = "adsp",
+		.ssctl_id = 0x14,
 };
 
 static const struct adsp_data slpi_resource_init = {
@@ -446,6 +456,8 @@ static const struct adsp_data slpi_resource_init = {
 		.pas_id = 12,
 		.has_aggre2_clk = true,
 		.ssr_name = "dsps",
+		.sysmon_name = "slpi",
+		.ssctl_id = 0x16,
 };
 
 static const struct of_device_id adsp_of_match[] = {
diff --git a/drivers/remoteproc/qcom_common.h b/drivers/remoteproc/qcom_common.h
index 4f8bc168473c..7def34bf8f39 100644
--- a/drivers/remoteproc/qcom_common.h
+++ b/drivers/remoteproc/qcom_common.h
@@ -3,6 +3,9 @@
 
 #include <linux/remoteproc.h>
 #include "remoteproc_internal.h"
+#include <linux/soc/qcom/qmi.h>
+
+struct qcom_sysmon;
 
 struct qcom_rproc_glink {
 	struct rproc_subdev subdev;
@@ -40,4 +43,22 @@ void qcom_add_ssr_subdev(struct rproc *rproc, struct qcom_rproc_ssr *ssr,
 			 const char *ssr_name);
 void qcom_remove_ssr_subdev(struct rproc *rproc, struct qcom_rproc_ssr *ssr);
 
+#if IS_ENABLED(CONFIG_QCOM_SYSMON)
+struct qcom_sysmon *qcom_add_sysmon_subdev(struct rproc *rproc,
+					   const char *name,
+					   int ssctl_instance);
+void qcom_remove_sysmon_subdev(struct qcom_sysmon *sysmon);
+#else
+static inline struct qcom_sysmon *qcom_add_sysmon_subdev(struct rproc *rproc,
+							 const char *name,
+							 int ssctl_instance)
+{
+	return NULL;
+}
+
+static inline void qcom_remove_sysmon_subdev(struct qcom_sysmon *sysmon)
+{
+}
+#endif
+
 #endif
diff --git a/drivers/remoteproc/qcom_q6v5_pil.c b/drivers/remoteproc/qcom_q6v5_pil.c
index 2d3d5ac92c06..714395d700ec 100644
--- a/drivers/remoteproc/qcom_q6v5_pil.c
+++ b/drivers/remoteproc/qcom_q6v5_pil.c
@@ -154,6 +154,7 @@ struct q6v5 {
 
 	struct qcom_rproc_subdev smd_subdev;
 	struct qcom_rproc_ssr ssr_subdev;
+	struct qcom_sysmon *sysmon;
 };
 
 static int q6v5_regulator_init(struct device *dev, struct reg_info *regs,
@@ -1041,6 +1042,7 @@ static int q6v5_probe(struct platform_device *pdev)
 
 	qcom_add_smd_subdev(rproc, &qproc->smd_subdev);
 	qcom_add_ssr_subdev(rproc, &qproc->ssr_subdev, "mpss");
+	qproc->sysmon = qcom_add_sysmon_subdev(rproc, "modem", 0x12);
 
 	ret = rproc_add(rproc);
 	if (ret)
@@ -1060,6 +1062,7 @@ static int q6v5_remove(struct platform_device *pdev)
 
 	rproc_del(qproc->rproc);
 
+	qcom_remove_sysmon_subdev(qproc->sysmon);
 	qcom_remove_smd_subdev(qproc->rproc, &qproc->smd_subdev);
 	qcom_remove_ssr_subdev(qproc->rproc, &qproc->ssr_subdev);
 	rproc_free(qproc->rproc);
diff --git a/drivers/remoteproc/qcom_sysmon.c b/drivers/remoteproc/qcom_sysmon.c
new file mode 100644
index 000000000000..e46634413075
--- /dev/null
+++ b/drivers/remoteproc/qcom_sysmon.c
@@ -0,0 +1,585 @@
+/*
+ * Copyright (c) 2017, Linaro Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+#include <linux/firmware.h>
+#include <linux/module.h>
+#include <linux/notifier.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/notifier.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/remoteproc/qcom_rproc.h>
+#include <linux/rpmsg.h>
+
+#include "qcom_common.h"
+
+static BLOCKING_NOTIFIER_HEAD(sysmon_notifiers);
+
+struct qcom_sysmon {
+	struct rproc_subdev subdev;
+	struct rproc *rproc;
+
+	struct list_head node;
+
+	const char *name;
+
+	int ssctl_version;
+	int ssctl_instance;
+
+	struct notifier_block nb;
+
+	struct device *dev;
+
+	struct rpmsg_endpoint *ept;
+	struct completion comp;
+	struct mutex lock;
+
+	bool ssr_ack;
+
+	struct qmi_handle qmi;
+	struct sockaddr_qrtr ssctl;
+};
+
+static DEFINE_MUTEX(sysmon_lock);
+static LIST_HEAD(sysmon_list);
+
+/**
+ * sysmon_send_event() - send notification of other remote's SSR event
+ * @sysmon:	sysmon context
+ * @name:	other remote's name
+ */
+static void sysmon_send_event(struct qcom_sysmon *sysmon, const char *name)
+{
+	char req[50];
+	int len;
+	int ret;
+
+	len = snprintf(req, sizeof(req), "ssr:%s:before_shutdown", name);
+	if (len >= sizeof(req))
+		return;
+
+	mutex_lock(&sysmon->lock);
+	reinit_completion(&sysmon->comp);
+	sysmon->ssr_ack = false;
+
+	ret = rpmsg_send(sysmon->ept, req, len);
+	if (ret < 0) {
+		dev_err(sysmon->dev, "failed to send sysmon event\n");
+		goto out_unlock;
+	}
+
+	ret = wait_for_completion_timeout(&sysmon->comp,
+					  msecs_to_jiffies(5000));
+	if (!ret) {
+		dev_err(sysmon->dev, "timeout waiting for sysmon ack\n");
+		goto out_unlock;
+	}
+
+	if (!sysmon->ssr_ack)
+		dev_err(sysmon->dev, "unexpected response to sysmon event\n");
+
+out_unlock:
+	mutex_unlock(&sysmon->lock);
+}
+
+/**
+ * sysmon_request_shutdown() - request graceful shutdown of remote
+ * @sysmon:	sysmon context
+ */
+static void sysmon_request_shutdown(struct qcom_sysmon *sysmon)
+{
+	char *req = "ssr:shutdown";
+	int ret;
+
+	mutex_lock(&sysmon->lock);
+	reinit_completion(&sysmon->comp);
+	sysmon->ssr_ack = false;
+
+	ret = rpmsg_send(sysmon->ept, req, strlen(req) + 1);
+	if (ret < 0) {
+		dev_err(sysmon->dev, "send sysmon shutdown request failed\n");
+		goto out_unlock;
+	}
+
+	ret = wait_for_completion_timeout(&sysmon->comp,
+					  msecs_to_jiffies(5000));
+	if (!ret) {
+		dev_err(sysmon->dev, "timeout waiting for sysmon ack\n");
+		goto out_unlock;
+	}
+
+	if (!sysmon->ssr_ack)
+		dev_err(sysmon->dev,
+			"unexpected response to sysmon shutdown request\n");
+
+out_unlock:
+	mutex_unlock(&sysmon->lock);
+}
+
+static int sysmon_callback(struct rpmsg_device *rpdev, void *data, int count,
+			   void *priv, u32 addr)
+{
+	struct qcom_sysmon *sysmon = priv;
+	const char *ssr_ack = "ssr:ack";
+	const int ssr_ack_len = strlen(ssr_ack) + 1;
+
+	if (!sysmon)
+		return -EINVAL;
+
+	if (count >= ssr_ack_len && !memcmp(data, ssr_ack, ssr_ack_len))
+		sysmon->ssr_ack = true;
+
+	complete(&sysmon->comp);
+
+	return 0;
+}
+
+#define SSCTL_SHUTDOWN_REQ		0x21
+#define SSCTL_SUBSYS_EVENT_REQ		0x23
+
+#define SSCTL_MAX_MSG_LEN		7
+
+#define SSCTL_SUBSYS_NAME_LENGTH	15
+
+enum {
+	SSCTL_SSR_EVENT_BEFORE_POWERUP,
+	SSCTL_SSR_EVENT_AFTER_POWERUP,
+	SSCTL_SSR_EVENT_BEFORE_SHUTDOWN,
+	SSCTL_SSR_EVENT_AFTER_SHUTDOWN,
+};
+
+enum {
+	SSCTL_SSR_EVENT_FORCED,
+	SSCTL_SSR_EVENT_GRACEFUL,
+};
+
+struct ssctl_shutdown_resp {
+	struct qmi_response_type_v01 resp;
+};
+
+static struct qmi_elem_info ssctl_shutdown_resp_ei[] = {
+	{
+		.data_type = QMI_STRUCT,
+		.elem_len  = 1,
+		.elem_size = sizeof(struct qmi_response_type_v01),
+		.is_array  = NO_ARRAY,
+		.tlv_type  = 0x02,
+		.offset    = offsetof(struct ssctl_shutdown_resp, resp),
+		.ei_array  = qmi_response_type_v01_ei,
+	},
+	{}
+};
+
+struct ssctl_subsys_event_req {
+	uint8_t subsys_name_len;
+	char subsys_name[SSCTL_SUBSYS_NAME_LENGTH];
+	u32 event;
+	uint8_t evt_driven_valid;
+	u32 evt_driven;
+};
+
+static struct qmi_elem_info ssctl_subsys_event_req_ei[] = {
+	{
+		.data_type = QMI_DATA_LEN,
+		.elem_len  = 1,
+		.elem_size = sizeof(uint8_t),
+		.is_array  = NO_ARRAY,
+		.tlv_type  = 0x01,
+		.offset    = offsetof(struct ssctl_subsys_event_req,
+				subsys_name_len),
+		.ei_array  = NULL,
+	},
+	{
+		.data_type = QMI_UNSIGNED_1_BYTE,
+		.elem_len  = SSCTL_SUBSYS_NAME_LENGTH,
+		.elem_size = sizeof(char),
+		.is_array  = VAR_LEN_ARRAY,
+		.tlv_type  = 0x01,
+		.offset    = offsetof(struct ssctl_subsys_event_req,
+				subsys_name),
+		.ei_array  = NULL,
+	},
+	{
+		.data_type = QMI_SIGNED_4_BYTE_ENUM,
+		.elem_len  = 1,
+		.elem_size = sizeof(uint32_t),
+		.is_array  = NO_ARRAY,
+		.tlv_type  = 0x02,
+		.offset    = offsetof(struct ssctl_subsys_event_req, event),
+		.ei_array  = NULL,
+	},
+	{
+		.data_type = QMI_OPT_FLAG,
+		.elem_len  = 1,
+		.elem_size = sizeof(uint8_t),
+		.is_array  = NO_ARRAY,
+		.tlv_type  = 0x10,
+		.offset    = offsetof(struct ssctl_subsys_event_req,
+				evt_driven_valid),
+		.ei_array  = NULL,
+	},
+	{
+		.data_type = QMI_SIGNED_4_BYTE_ENUM,
+		.elem_len  = 1,
+		.elem_size = sizeof(uint32_t),
+		.is_array  = NO_ARRAY,
+		.tlv_type  = 0x10,
+		.offset    = offsetof(struct ssctl_subsys_event_req,
+				evt_driven),
+		.ei_array  = NULL,
+	},
+	{}
+};
+
+struct ssctl_subsys_event_resp {
+	struct qmi_response_type_v01 resp;
+};
+
+static struct qmi_elem_info ssctl_subsys_event_resp_ei[] = {
+	{
+		.data_type = QMI_STRUCT,
+		.elem_len  = 1,
+		.elem_size = sizeof(struct qmi_response_type_v01),
+		.is_array  = NO_ARRAY,
+		.tlv_type  = 0x02,
+		.offset    = offsetof(struct ssctl_subsys_event_resp, resp),
+		.ei_array  = qmi_response_type_v01_ei,
+	},
+	{}
+};
+
+/**
+ * ssctl_request_shutdown() - request shutdown via SSCTL QMI service
+ * @sysmon:	sysmon context
+ */
+static void ssctl_request_shutdown(struct qcom_sysmon *sysmon)
+{
+	struct ssctl_shutdown_resp resp;
+	struct qmi_txn txn;
+	int ret;
+
+	ret = qmi_txn_init(&sysmon->qmi, &txn, ssctl_shutdown_resp_ei, &resp);
+	if (ret < 0) {
+		dev_err(sysmon->dev, "failed to allocate QMI txn\n");
+		return;
+	}
+
+	ret = qmi_send_request(&sysmon->qmi, &sysmon->ssctl, &txn,
+			       SSCTL_SHUTDOWN_REQ, 0, NULL, NULL);
+	if (ret < 0) {
+		dev_err(sysmon->dev, "failed to send shutdown request\n");
+		qmi_txn_cancel(&txn);
+		return;
+	}
+
+	ret = qmi_txn_wait(&txn, 5 * HZ);
+	if (ret < 0)
+		dev_err(sysmon->dev, "failed receiving QMI response\n");
+	else if (resp.resp.result)
+		dev_err(sysmon->dev, "shutdown request failed\n");
+	else
+		dev_dbg(sysmon->dev, "shutdown request completed\n");
+}
+
+/**
+ * ssctl_send_event() - send notification of other remote's SSR event
+ * @sysmon:	sysmon context
+ * @name:	other remote's name
+ */
+static void ssctl_send_event(struct qcom_sysmon *sysmon, const char *name)
+{
+	struct ssctl_subsys_event_resp resp;
+	struct ssctl_subsys_event_req req;
+	struct qmi_txn txn;
+	int ret;
+
+	memset(&resp, 0, sizeof(resp));
+	ret = qmi_txn_init(&sysmon->qmi, &txn, ssctl_subsys_event_resp_ei, &resp);
+	if (ret < 0) {
+		dev_err(sysmon->dev, "failed to allocate QMI txn\n");
+		return;
+	}
+
+	memset(&req, 0, sizeof(req));
+	strlcpy(req.subsys_name, name, sizeof(req.subsys_name));
+	req.subsys_name_len = strlen(req.subsys_name);
+	req.event = SSCTL_SSR_EVENT_BEFORE_SHUTDOWN;
+	req.evt_driven_valid = true;
+	req.evt_driven = SSCTL_SSR_EVENT_FORCED;
+
+	ret = qmi_send_request(&sysmon->qmi, &sysmon->ssctl, &txn,
+			       SSCTL_SUBSYS_EVENT_REQ, 40,
+			       ssctl_subsys_event_req_ei, &req);
+	if (ret < 0) {
+		dev_err(sysmon->dev, "failed to send shutdown request\n");
+		qmi_txn_cancel(&txn);
+		return;
+	}
+
+	ret = qmi_txn_wait(&txn, 5 * HZ);
+	if (ret < 0)
+		dev_err(sysmon->dev, "failed receiving QMI response\n");
+	else if (resp.resp.result)
+		dev_err(sysmon->dev, "ssr event send failed\n");
+	else
+		dev_dbg(sysmon->dev, "ssr event send completed\n");
+}
+
+/**
+ * ssctl_new_server() - QMI callback indicating a new service
+ * @qmi:	QMI handle
+ * @svc:	service information
+ *
+ * Returns 0 if we're interested in this service, -EINVAL otherwise.
+ */
+static int ssctl_new_server(struct qmi_handle *qmi, struct qmi_service *svc)
+{
+	struct qcom_sysmon *sysmon = container_of(qmi, struct qcom_sysmon, qmi);
+
+	switch (svc->version) {
+	case 1:
+		if (svc->instance != 0)
+			return -EINVAL;
+		if (strcmp(sysmon->name, "modem"))
+			return -EINVAL;
+		break;
+	case 2:
+		if (svc->instance != sysmon->ssctl_instance)
+			return -EINVAL;
+		break;
+	default:
+		return -EINVAL;
+	};
+
+	sysmon->ssctl_version = svc->version;
+
+	sysmon->ssctl.sq_family = AF_QIPCRTR;
+	sysmon->ssctl.sq_node = svc->node;
+	sysmon->ssctl.sq_port = svc->port;
+
+	svc->priv = sysmon;
+
+	return 0;
+}
+
+/**
+ * ssctl_del_server() - QMI callback indicating that @svc is removed
+ * @qmi:	QMI handle
+ * @svc:	service information
+ */
+static void ssctl_del_server(struct qmi_handle *qmi, struct qmi_service *svc)
+{
+	struct qcom_sysmon *sysmon = svc->priv;
+
+	sysmon->ssctl_version = 0;
+}
+
+struct qmi_ops ssctl_ops = {
+	.new_server = ssctl_new_server,
+	.del_server = ssctl_del_server,
+};
+
+static int sysmon_start(struct rproc_subdev *subdev)
+{
+	return  0;
+}
+
+static void sysmon_stop(struct rproc_subdev *subdev, bool graceful)
+{
+	struct qcom_sysmon *sysmon = container_of(subdev, struct qcom_sysmon, subdev);
+
+	blocking_notifier_call_chain(&sysmon_notifiers, 0, (void *)sysmon->name);
+
+	/* Don't request graceful shutdown if we've crashed */
+	if (!graceful)
+		return;
+
+	if (sysmon->ssctl_version)
+		ssctl_request_shutdown(sysmon);
+	else if (sysmon->ept)
+		sysmon_request_shutdown(sysmon);
+}
+
+/**
+ * sysmon_notify() - notify sysmon target of another's SSR
+ * @nb:		notifier_block associated with sysmon instance
+ * @event:	unused
+ * @data:	SSR identifier of the remote that is going down
+ */
+static int sysmon_notify(struct notifier_block *nb, unsigned long event,
+			 void *data)
+{
+	struct qcom_sysmon *sysmon = container_of(nb, struct qcom_sysmon, nb);
+	struct rproc *rproc = sysmon->rproc;
+	const char *ssr_name = data;
+
+	/* Skip non-running rprocs and the originating instance */
+	if (rproc->state != RPROC_RUNNING || !strcmp(data, sysmon->name)) {
+		dev_dbg(sysmon->dev, "not notifying %s\n", sysmon->name);
+		return NOTIFY_DONE;
+	}
+
+	/* Only SSCTL version 2 supports SSR events */
+	if (sysmon->ssctl_version == 2)
+		ssctl_send_event(sysmon, ssr_name);
+	else if (sysmon->ept)
+		sysmon_send_event(sysmon, ssr_name);
+
+	return NOTIFY_DONE;
+}
+
+/**
+ * qcom_add_sysmon_subdev() - create a sysmon subdev for the given remoteproc
+ * @rproc:	rproc context to associate the subdev with
+ * @name:	name of this subdev, to use in SSR
+ * @ssctl_instance: instance id of the ssctl QMI service
+ *
+ * Returns a new qcom_sysmon object, or NULL on failure
+ */
+struct qcom_sysmon *qcom_add_sysmon_subdev(struct rproc *rproc,
+					   const char *name,
+					   int ssctl_instance)
+{
+	struct qcom_sysmon *sysmon;
+	int ret;
+
+	sysmon = kzalloc(sizeof(*sysmon), GFP_KERNEL);
+	if (!sysmon)
+		return NULL;
+
+	sysmon->dev = rproc->dev.parent;
+	sysmon->rproc = rproc;
+
+	sysmon->name = name;
+	sysmon->ssctl_instance = ssctl_instance;
+
+	init_completion(&sysmon->comp);
+	mutex_init(&sysmon->lock);
+
+	ret = qmi_handle_init(&sysmon->qmi, SSCTL_MAX_MSG_LEN, &ssctl_ops, NULL);
+	if (ret < 0) {
+		dev_err(sysmon->dev, "failed to initialize qmi handle\n");
+		kfree(sysmon);
+		return NULL;
+	}
+
+	qmi_add_lookup(&sysmon->qmi, 43, 0, 0);
+
+	rproc_add_subdev(rproc, &sysmon->subdev, sysmon_start, sysmon_stop);
+
+	sysmon->nb.notifier_call = sysmon_notify;
+	blocking_notifier_chain_register(&sysmon_notifiers, &sysmon->nb);
+
+	mutex_lock(&sysmon_lock);
+	list_add(&sysmon->node, &sysmon_list);
+	mutex_unlock(&sysmon_lock);
+
+	return sysmon;
+}
+EXPORT_SYMBOL_GPL(qcom_add_sysmon_subdev);
+
+/**
+ * qcom_remove_sysmon_subdev() - release a qcom_sysmon
+ * @sysmon:	sysmon context, as retrieved by qcom_add_sysmon_subdev()
+ */
+void qcom_remove_sysmon_subdev(struct qcom_sysmon *sysmon)
+{
+	if (!sysmon)
+		return;
+
+	mutex_lock(&sysmon_lock);
+	list_del(&sysmon->node);
+	mutex_unlock(&sysmon_lock);
+
+	blocking_notifier_chain_unregister(&sysmon_notifiers, &sysmon->nb);
+
+	rproc_remove_subdev(sysmon->rproc, &sysmon->subdev);
+
+	qmi_handle_release(&sysmon->qmi);
+
+	kfree(sysmon);
+}
+EXPORT_SYMBOL_GPL(qcom_remove_sysmon_subdev);
+
+/**
+ * sysmon_probe() - probe sys_mon channel
+ * @rpdev:	rpmsg device handle
+ *
+ * Returns 0 on success, negative errno on failure.
+ *
+ * Find the sysmon context associated with the ancestor remoteproc and assign
+ * this rpmsg device with said sysmon context.
+ */
+static int sysmon_probe(struct rpmsg_device *rpdev)
+{
+	struct qcom_sysmon *sysmon;
+	struct rproc *rproc;
+
+	rproc = rproc_get_by_child(&rpdev->dev);
+	if (!rproc) {
+		dev_err(&rpdev->dev, "sysmon device not child of rproc\n");
+		return -EINVAL;
+	}
+
+	mutex_lock(&sysmon_lock);
+	list_for_each_entry(sysmon, &sysmon_list, node) {
+		if (sysmon->rproc == rproc)
+			goto found;
+	}
+	mutex_unlock(&sysmon_lock);
+
+	dev_err(&rpdev->dev, "no sysmon associated with parent rproc\n");
+
+	return -EINVAL;
+
+found:
+	mutex_unlock(&sysmon_lock);
+
+	rpdev->ept->priv = sysmon;
+	sysmon->ept = rpdev->ept;
+
+	return 0;
+}
+
+/**
+ * sysmon_remove() - sys_mon channel remove handler
+ * @rpdev:	rpmsg device handle
+ *
+ * Disassociate the rpmsg device with the sysmon instance.
+ */
+static void sysmon_remove(struct rpmsg_device *rpdev)
+{
+	struct qcom_sysmon *sysmon = rpdev->ept->priv;
+
+	sysmon->ept = NULL;
+}
+
+static const struct rpmsg_device_id sysmon_match[] = {
+	{ "sys_mon" },
+	{}
+};
+
+static struct rpmsg_driver sysmon_driver = {
+	.probe = sysmon_probe,
+	.remove = sysmon_remove,
+	.callback = sysmon_callback,
+	.id_table = sysmon_match,
+	.drv  = {
+		.name  = "qcom_sysmon",
+	},
+};
+
+module_rpmsg_driver(sysmon_driver);
+
+MODULE_DESCRIPTION("Qualcomm sysmon driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/remoteproc/qcom_wcnss.c b/drivers/remoteproc/qcom_wcnss.c
index c7686393d505..dc79239c43f9 100644
--- a/drivers/remoteproc/qcom_wcnss.c
+++ b/drivers/remoteproc/qcom_wcnss.c
@@ -40,6 +40,7 @@
 #define WCNSS_CRASH_REASON_SMEM		422
 #define WCNSS_FIRMWARE_NAME		"wcnss.mdt"
 #define WCNSS_PAS_ID			6
+#define WCNSS_SSCTL_ID			0x13
 
 #define WCNSS_SPARE_NVBIN_DLND		BIT(25)
 
@@ -98,6 +99,7 @@ struct qcom_wcnss {
 	size_t mem_size;
 
 	struct qcom_rproc_subdev smd_subdev;
+	struct qcom_sysmon *sysmon;
 };
 
 static const struct wcnss_data riva_data = {
@@ -557,6 +559,7 @@ static int wcnss_probe(struct platform_device *pdev)
 	}
 
 	qcom_add_smd_subdev(rproc, &wcnss->smd_subdev);
+	wcnss->sysmon = qcom_add_sysmon_subdev(rproc, "wcnss", WCNSS_SSCTL_ID);
 
 	ret = rproc_add(rproc);
 	if (ret)
@@ -579,6 +582,7 @@ static int wcnss_remove(struct platform_device *pdev)
 	qcom_smem_state_put(wcnss->state);
 	rproc_del(wcnss->rproc);
 
+	qcom_remove_sysmon_subdev(wcnss->sysmon);
 	qcom_remove_smd_subdev(wcnss->rproc, &wcnss->smd_subdev);
 	rproc_free(wcnss->rproc);
 
-- 
2.15.0

[PATCH v2 5/5] samples: Introduce Qualcomm QMI sample client

[Bjorn Andersson]

Introduce a sample driver that register for server notifications and
spawn clients for each available test service (service 15). The spawned
clients implements the interface for encoding "ping" and "data" requests
and decode the responses from the remote.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
---

Changes since v1:
- Adapted to updated QMI helper interface
- Moved user space interface to debugfs

 samples/Kconfig                 |   9 +
 samples/Makefile                |   2 +-
 samples/qmi/Makefile            |   1 +
 samples/qmi/qmi_sample_client.c | 631 ++++++++++++++++++++++++++++++++++++++++
 4 files changed, 642 insertions(+), 1 deletion(-)
 create mode 100644 samples/qmi/Makefile
 create mode 100644 samples/qmi/qmi_sample_client.c

diff --git a/samples/Kconfig b/samples/Kconfig
index 9cb63188d3ef..8b20210b1eee 100644
--- a/samples/Kconfig
+++ b/samples/Kconfig
@@ -62,6 +62,15 @@ config SAMPLE_KDB
 	  Build an example of how to dynamically add the hello
 	  command to the kdb shell.
 
+config SAMPLE_QMI_CLIENT
+	tristate "Build qmi client sample -- loadable modules only"
+	depends on m
+	depends on ARCH_QCOM
+	select QCOM_QMI_HELPERS
+	help
+	  Build an QMI client sample driver, which demonstrates how to
+	  communicate with a remote QRTR service, using QMI encoded messages.
+
 config SAMPLE_RPMSG_CLIENT
 	tristate "Build rpmsg client sample -- loadable modules only"
 	depends on RPMSG && m
diff --git a/samples/Makefile b/samples/Makefile
index db54e766ddb1..a30833a2a19e 100644
--- a/samples/Makefile
+++ b/samples/Makefile
@@ -3,4 +3,4 @@
 obj-$(CONFIG_SAMPLES)	+= kobject/ kprobes/ trace_events/ livepatch/ \
 			   hw_breakpoint/ kfifo/ kdb/ hidraw/ rpmsg/ seccomp/ \
 			   configfs/ connector/ v4l/ trace_printk/ blackfin/ \
-			   vfio-mdev/ statx/
+			   vfio-mdev/ statx/ qmi/
diff --git a/samples/qmi/Makefile b/samples/qmi/Makefile
new file mode 100644
index 000000000000..2b111d2769df
--- /dev/null
+++ b/samples/qmi/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_SAMPLE_QMI_CLIENT) += qmi_sample_client.o
diff --git a/samples/qmi/qmi_sample_client.c b/samples/qmi/qmi_sample_client.c
new file mode 100644
index 000000000000..4d90e8b71691
--- /dev/null
+++ b/samples/qmi/qmi_sample_client.c
@@ -0,0 +1,631 @@
+/*
+ * Sample in-kernel QMI client driver
+ *
+ * Copyright (c) 2013-2014, The Linux Foundation. All rights reserved.
+ * Copyright (C) 2017 Linaro Ltd.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/debugfs.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/qrtr.h>
+#include <linux/net.h>
+#include <linux/completion.h>
+#include <linux/idr.h>
+#include <linux/string.h>
+#include <net/sock.h>
+#include <linux/soc/qcom/qmi.h>
+
+#define PING_REQ1_TLV_TYPE		0x1
+#define PING_RESP1_TLV_TYPE		0x2
+#define PING_OPT1_TLV_TYPE		0x10
+#define PING_OPT2_TLV_TYPE		0x11
+
+#define DATA_REQ1_TLV_TYPE		0x1
+#define DATA_RESP1_TLV_TYPE		0x2
+#define DATA_OPT1_TLV_TYPE		0x10
+#define DATA_OPT2_TLV_TYPE		0x11
+
+#define TEST_MED_DATA_SIZE_V01		8192
+#define TEST_MAX_NAME_SIZE_V01		255
+
+#define TEST_PING_REQ_MSG_ID_V01	0x20
+#define TEST_DATA_REQ_MSG_ID_V01	0x21
+
+#define TEST_PING_REQ_MAX_MSG_LEN_V01	266
+#define TEST_DATA_REQ_MAX_MSG_LEN_V01	8456
+
+struct test_name_type_v01 {
+	uint32_t name_len;
+	char name[TEST_MAX_NAME_SIZE_V01];
+};
+
+static struct qmi_elem_info test_name_type_v01_ei[] = {
+	{
+		.data_type      = QMI_DATA_LEN,
+		.elem_len	= 1,
+		.elem_size      = sizeof(uint8_t),
+		.is_array	= NO_ARRAY,
+		.tlv_type	= QMI_COMMON_TLV_TYPE,
+		.offset		= offsetof(struct test_name_type_v01,
+					   name_len),
+	},
+	{
+		.data_type      = QMI_UNSIGNED_1_BYTE,
+		.elem_len       = TEST_MAX_NAME_SIZE_V01,
+		.elem_size      = sizeof(char),
+		.is_array       = VAR_LEN_ARRAY,
+		.tlv_type       = QMI_COMMON_TLV_TYPE,
+		.offset         = offsetof(struct test_name_type_v01,
+					   name),
+	},
+	{}
+};
+
+struct test_ping_req_msg_v01 {
+	char ping[4];
+
+	uint8_t client_name_valid;
+	struct test_name_type_v01 client_name;
+};
+
+struct qmi_elem_info test_ping_req_msg_v01_ei[] = {
+	{
+		.data_type      = QMI_UNSIGNED_1_BYTE,
+		.elem_len       = 4,
+		.elem_size      = sizeof(char),
+		.is_array       = STATIC_ARRAY,
+		.tlv_type       = PING_REQ1_TLV_TYPE,
+		.offset         = offsetof(struct test_ping_req_msg_v01,
+					   ping),
+	},
+	{
+		.data_type      = QMI_OPT_FLAG,
+		.elem_len       = 1,
+		.elem_size      = sizeof(uint8_t),
+		.is_array       = NO_ARRAY,
+		.tlv_type       = PING_OPT1_TLV_TYPE,
+		.offset         = offsetof(struct test_ping_req_msg_v01,
+					   client_name_valid),
+	},
+	{
+		.data_type      = QMI_STRUCT,
+		.elem_len       = 1,
+		.elem_size      = sizeof(struct test_name_type_v01),
+		.is_array       = NO_ARRAY,
+		.tlv_type       = PING_OPT1_TLV_TYPE,
+		.offset         = offsetof(struct test_ping_req_msg_v01,
+					   client_name),
+		.ei_array       = test_name_type_v01_ei,
+	},
+	{}
+};
+
+struct test_ping_resp_msg_v01 {
+	struct qmi_response_type_v01 resp;
+
+	uint8_t pong_valid;
+	char pong[4];
+
+	uint8_t service_name_valid;
+	struct test_name_type_v01 service_name;
+};
+
+struct qmi_elem_info test_ping_resp_msg_v01_ei[] = {
+	{
+		.data_type      = QMI_STRUCT,
+		.elem_len       = 1,
+		.elem_size      = sizeof(struct qmi_response_type_v01),
+		.is_array       = NO_ARRAY,
+		.tlv_type       = PING_RESP1_TLV_TYPE,
+		.offset         = offsetof(struct test_ping_resp_msg_v01,
+					   resp),
+		.ei_array       = qmi_response_type_v01_ei,
+	},
+	{
+		.data_type      = QMI_OPT_FLAG,
+		.elem_len       = 1,
+		.elem_size      = sizeof(uint8_t),
+		.is_array       = NO_ARRAY,
+		.tlv_type       = PING_OPT1_TLV_TYPE,
+		.offset         = offsetof(struct test_ping_resp_msg_v01,
+					   pong_valid),
+	},
+	{
+		.data_type      = QMI_UNSIGNED_1_BYTE,
+		.elem_len       = 4,
+		.elem_size      = sizeof(char),
+		.is_array       = STATIC_ARRAY,
+		.tlv_type       = PING_OPT1_TLV_TYPE,
+		.offset         = offsetof(struct test_ping_resp_msg_v01,
+					   pong),
+	},
+	{
+		.data_type      = QMI_OPT_FLAG,
+		.elem_len       = 1,
+		.elem_size      = sizeof(uint8_t),
+		.is_array       = NO_ARRAY,
+		.tlv_type       = PING_OPT2_TLV_TYPE,
+		.offset         = offsetof(struct test_ping_resp_msg_v01,
+					   service_name_valid),
+	},
+	{
+		.data_type      = QMI_STRUCT,
+		.elem_len       = 1,
+		.elem_size      = sizeof(struct test_name_type_v01),
+		.is_array       = NO_ARRAY,
+		.tlv_type       = PING_OPT2_TLV_TYPE,
+		.offset         = offsetof(struct test_ping_resp_msg_v01,
+					   service_name),
+		.ei_array       = test_name_type_v01_ei,
+	},
+	{}
+};
+
+struct test_data_req_msg_v01 {
+	uint32_t data_len;
+	uint8_t data[TEST_MED_DATA_SIZE_V01];
+
+	uint8_t client_name_valid;
+	struct test_name_type_v01 client_name;
+};
+
+struct qmi_elem_info test_data_req_msg_v01_ei[] = {
+	{
+		.data_type      = QMI_DATA_LEN,
+		.elem_len       = 1,
+		.elem_size      = sizeof(uint32_t),
+		.is_array       = NO_ARRAY,
+		.tlv_type       = DATA_REQ1_TLV_TYPE,
+		.offset         = offsetof(struct test_data_req_msg_v01,
+					   data_len),
+	},
+	{
+		.data_type      = QMI_UNSIGNED_1_BYTE,
+		.elem_len       = TEST_MED_DATA_SIZE_V01,
+		.elem_size      = sizeof(uint8_t),
+		.is_array       = VAR_LEN_ARRAY,
+		.tlv_type       = DATA_REQ1_TLV_TYPE,
+		.offset         = offsetof(struct test_data_req_msg_v01,
+					   data),
+	},
+	{
+		.data_type      = QMI_OPT_FLAG,
+		.elem_len       = 1,
+		.elem_size      = sizeof(uint8_t),
+		.is_array       = NO_ARRAY,
+		.tlv_type       = DATA_OPT1_TLV_TYPE,
+		.offset         = offsetof(struct test_data_req_msg_v01,
+					   client_name_valid),
+	},
+	{
+		.data_type      = QMI_STRUCT,
+		.elem_len       = 1,
+		.elem_size      = sizeof(struct test_name_type_v01),
+		.is_array       = NO_ARRAY,
+		.tlv_type       = DATA_OPT1_TLV_TYPE,
+		.offset         = offsetof(struct test_data_req_msg_v01,
+					   client_name),
+		.ei_array       = test_name_type_v01_ei,
+	},
+	{}
+};
+
+struct test_data_resp_msg_v01 {
+	struct qmi_response_type_v01 resp;
+
+	uint8_t data_valid;
+	uint32_t data_len;
+	uint8_t data[TEST_MED_DATA_SIZE_V01];
+
+	uint8_t service_name_valid;
+	struct test_name_type_v01 service_name;
+};
+
+struct qmi_elem_info test_data_resp_msg_v01_ei[] = {
+	{
+		.data_type      = QMI_STRUCT,
+		.elem_len       = 1,
+		.elem_size      = sizeof(struct qmi_response_type_v01),
+		.is_array       = NO_ARRAY,
+		.tlv_type       = DATA_RESP1_TLV_TYPE,
+		.offset         = offsetof(struct test_data_resp_msg_v01,
+					   resp),
+		.ei_array       = qmi_response_type_v01_ei,
+	},
+	{
+		.data_type      = QMI_OPT_FLAG,
+		.elem_len       = 1,
+		.elem_size      = sizeof(uint8_t),
+		.is_array       = NO_ARRAY,
+		.tlv_type       = DATA_OPT1_TLV_TYPE,
+		.offset         = offsetof(struct test_data_resp_msg_v01,
+					   data_valid),
+	},
+	{
+		.data_type      = QMI_DATA_LEN,
+		.elem_len       = 1,
+		.elem_size      = sizeof(uint32_t),
+		.is_array       = NO_ARRAY,
+		.tlv_type       = DATA_OPT1_TLV_TYPE,
+		.offset         = offsetof(struct test_data_resp_msg_v01,
+					   data_len),
+	},
+	{
+		.data_type      = QMI_UNSIGNED_1_BYTE,
+		.elem_len       = TEST_MED_DATA_SIZE_V01,
+		.elem_size      = sizeof(uint8_t),
+		.is_array       = VAR_LEN_ARRAY,
+		.tlv_type       = DATA_OPT1_TLV_TYPE,
+		.offset         = offsetof(struct test_data_resp_msg_v01,
+					   data),
+	},
+	{
+		.data_type      = QMI_OPT_FLAG,
+		.elem_len       = 1,
+		.elem_size      = sizeof(uint8_t),
+		.is_array       = NO_ARRAY,
+		.tlv_type       = DATA_OPT2_TLV_TYPE,
+		.offset         = offsetof(struct test_data_resp_msg_v01,
+					   service_name_valid),
+	},
+	{
+		.data_type      = QMI_STRUCT,
+		.elem_len       = 1,
+		.elem_size      = sizeof(struct test_name_type_v01),
+		.is_array       = NO_ARRAY,
+		.tlv_type       = DATA_OPT2_TLV_TYPE,
+		.offset         = offsetof(struct test_data_resp_msg_v01,
+					   service_name),
+		.ei_array       = test_name_type_v01_ei,
+	},
+	{}
+};
+
+/*
+ * ping_pong_store() - ping_pong debugfs file write handler
+ * @file:	debugfs file context
+ * @user_buf:	reference to the user data
+ * @count:	number of bytes in @user_buf
+ * @ppos:	offset in @file to write
+ *
+ * Returns @count, or negative errno on failure.
+ *
+ * This function allows user space to send out a ping_pong QMI encoded message
+ * to the associated remote test service and will return with the result of the
+ * transaction. It serves as an example of how to provide a custom response
+ * handler.
+ */
+static ssize_t ping_write(struct file *file, const char __user *user_buf,
+			  size_t count, loff_t *ppos)
+{
+	struct qmi_handle *qmi = file->private_data;
+	struct test_ping_req_msg_v01 req = {0};
+	struct qmi_txn txn;
+	int ret;
+
+	memcpy(req.ping, "ping", sizeof(req.ping));
+
+	ret = qmi_txn_init(qmi, &txn, NULL, NULL);
+	if (ret < 0)
+		return ret;
+
+	ret = qmi_send_request(qmi, NULL, &txn,
+			       TEST_PING_REQ_MSG_ID_V01,
+			       TEST_PING_REQ_MAX_MSG_LEN_V01,
+			       test_ping_req_msg_v01_ei, &req);
+	if (ret < 0) {
+		qmi_txn_cancel(&txn);
+		return ret;
+	}
+
+	ret = qmi_txn_wait(&txn, 5 * HZ);
+	if (ret < 0)
+		count = ret;
+
+	return count;
+}
+
+static const struct file_operations ping_fops = {
+	.open = simple_open,
+	.write = ping_write,
+};
+
+static void ping_pong_cb(struct qmi_handle *qmi, struct sockaddr_qrtr *sq,
+			 struct qmi_txn *txn, const void *data)
+{
+	const struct test_ping_resp_msg_v01 *resp = data;
+
+	if (!txn) {
+		pr_err("spurious ping response\n");
+		return;
+	}
+
+	if (resp->resp.result == QMI_RESULT_FAILURE_V01)
+		txn->result = -ENXIO;
+	else if (!resp->pong_valid || memcmp(resp->pong, "pong", 4))
+		txn->result = -EINVAL;
+
+	complete(&txn->completion);
+}
+
+/*
+ * data_store() - data debugfs file write handler
+ * @file:	debugfs file context
+ * @user_buf:	reference to the user data
+ * @count:	number of bytes in @user_buf
+ * @ppos:	offset in @file to write
+ *
+ * Returns @count, or negative errno on failure.
+ *
+ * This function allows user space to send out a data QMI encoded message to
+ * the associated remote test service and will return with the result of the
+ * transaction. It serves as an example of how to have the QMI helpers decode a
+ * transaction response into a provided object automatically.
+ */
+static ssize_t data_write(struct file *file, const char __user *user_buf,
+			  size_t count, loff_t *ppos)
+
+{
+	struct qmi_handle *qmi = file->private_data;
+	struct test_data_resp_msg_v01 *resp;
+	struct test_data_req_msg_v01 *req;
+	struct qmi_txn txn;
+	int ret;
+
+	req = kzalloc(sizeof(*req), GFP_KERNEL);
+	if (!req)
+		return -ENOMEM;
+
+	resp = kzalloc(sizeof(*resp), GFP_KERNEL);
+	if (!resp) {
+		kfree(req);
+		return -ENOMEM;
+	}
+
+	req->data_len = min_t(size_t, sizeof(req->data), count);
+	if (copy_from_user(req->data, user_buf, req->data_len)) {
+		ret = -EFAULT;
+		goto out;
+	}
+
+	ret = qmi_txn_init(qmi, &txn, test_data_resp_msg_v01_ei, resp);
+	if (ret < 0)
+		goto out;
+
+	ret = qmi_send_request(qmi, NULL, &txn,
+			       TEST_DATA_REQ_MSG_ID_V01,
+			       TEST_DATA_REQ_MAX_MSG_LEN_V01,
+			       test_data_req_msg_v01_ei, req);
+	if (ret < 0) {
+		qmi_txn_cancel(&txn);
+		goto out;
+	}
+
+	ret = qmi_txn_wait(&txn, 5 * HZ);
+	if (ret < 0) {
+		goto out;
+	} else if (!resp->data_valid ||
+		   resp->data_len != req->data_len ||
+		   memcmp(resp->data, req->data, req->data_len)) {
+		pr_err("response data doesn't match expectation\n");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	ret = count;
+
+out:
+	kfree(resp);
+	kfree(req);
+
+	return ret;
+}
+
+static const struct file_operations data_fops = {
+	.open = simple_open,
+	.write = data_write,
+};
+
+static struct qmi_msg_handler qmi_sample_handlers[] = {
+	{
+		.type = QMI_RESPONSE,
+		.msg_id = TEST_PING_REQ_MSG_ID_V01,
+		.ei = test_ping_resp_msg_v01_ei,
+		.decoded_size = sizeof(struct test_ping_req_msg_v01),
+		.fn = ping_pong_cb
+	},
+	{}
+};
+
+struct qmi_sample {
+	struct qmi_handle qmi;
+
+	struct dentry *de_dir;
+	struct dentry *de_data;
+	struct dentry *de_ping;
+};
+
+static struct dentry *qmi_debug_dir;
+
+static int qmi_sample_probe(struct platform_device *pdev)
+{
+	struct sockaddr_qrtr *sq;
+	struct qmi_sample *sample;
+	char path[20];
+	int ret;
+
+	sample = devm_kzalloc(&pdev->dev, sizeof(*sample), GFP_KERNEL);
+	if (!sample)
+		return -ENOMEM;
+
+	ret = qmi_handle_init(&sample->qmi, TEST_DATA_REQ_MAX_MSG_LEN_V01,
+			      NULL,
+			      qmi_sample_handlers);
+	if (ret < 0)
+		return ret;
+
+	sq = dev_get_platdata(&pdev->dev);
+	ret = kernel_connect(sample->qmi.sock, (struct sockaddr *)sq,
+			     sizeof(*sq), 0);
+	if (ret < 0) {
+		pr_err("failed to connect to remote service port\n");
+		goto err_release_qmi_handle;
+	}
+
+	snprintf(path, sizeof(path), "%d:%d", sq->sq_node, sq->sq_port);
+
+	sample->de_dir = debugfs_create_dir(path, qmi_debug_dir);
+	if (IS_ERR(sample->de_dir)) {
+		ret = PTR_ERR(sample->de_dir);
+		goto err_release_qmi_handle;
+	}
+
+	sample->de_data = debugfs_create_file("data", 0600, sample->de_dir,
+					      sample, &data_fops);
+	if (IS_ERR(sample->de_data)) {
+		ret = PTR_ERR(sample->de_data);
+		goto err_remove_de_dir;
+	}
+
+	sample->de_ping = debugfs_create_file("ping", 0600, sample->de_dir,
+					      sample, &ping_fops);
+	if (IS_ERR(sample->de_ping)) {
+		ret = PTR_ERR(sample->de_ping);
+		goto err_remove_de_data;
+	}
+
+	platform_set_drvdata(pdev, sample);
+
+	return 0;
+
+err_remove_de_data:
+	debugfs_remove(sample->de_data);
+err_remove_de_dir:
+	debugfs_remove(sample->de_dir);
+err_release_qmi_handle:
+	qmi_handle_release(&sample->qmi);
+
+	return ret;
+}
+
+static int qmi_sample_remove(struct platform_device *pdev)
+{
+	struct qmi_sample *sample = platform_get_drvdata(pdev);
+
+	debugfs_remove(sample->de_ping);
+	debugfs_remove(sample->de_data);
+	debugfs_remove(sample->de_dir);
+
+	qmi_handle_release(&sample->qmi);
+
+	return 0;
+}
+
+static struct platform_driver qmi_sample_driver = {
+	.probe = qmi_sample_probe,
+	.remove = qmi_sample_remove,
+	.driver = {
+		.name = "qmi_sample_client",
+	},
+};
+
+static int qmi_sample_new_server(struct qmi_handle *qmi,
+				  struct qmi_service *service)
+{
+	struct platform_device *pdev;
+	struct sockaddr_qrtr sq = { AF_QIPCRTR, service->node, service->port };
+	int ret;
+
+	pdev = platform_device_alloc("qmi_sample_client", PLATFORM_DEVID_AUTO);
+	if (!pdev)
+		return -ENOMEM;
+
+	ret = platform_device_add_data(pdev, &sq, sizeof(sq));
+	if (ret)
+		goto err_put_device;
+
+	ret = platform_device_add(pdev);
+	if (ret)
+		goto err_put_device;
+
+	service->priv = pdev;
+
+	return 0;
+
+err_put_device:
+	platform_device_put(pdev);
+
+	return ret;
+}
+
+static void qmi_sample_del_server(struct qmi_handle *qmi,
+				   struct qmi_service *service)
+{
+	struct platform_device *pdev = service->priv;
+
+	platform_device_unregister(pdev);
+}
+
+static struct qmi_handle lookup_client;
+
+static struct qmi_ops lookup_ops = {
+	.new_server = qmi_sample_new_server,
+	.del_server = qmi_sample_del_server,
+};
+
+static int qmi_sample_init(void)
+{
+	int ret;
+
+	qmi_debug_dir = debugfs_create_dir("qmi_sample", NULL);
+	if (IS_ERR(qmi_debug_dir)) {
+		pr_err("failed to create qmi_sample dir\n");
+		return PTR_ERR(qmi_debug_dir);
+	}
+
+	ret = platform_driver_register(&qmi_sample_driver);
+	if (ret)
+		goto err_remove_debug_dir;
+
+	ret = qmi_handle_init(&lookup_client, 0, &lookup_ops, NULL);
+	if (ret < 0)
+		goto err_unregister_driver;
+
+	qmi_add_lookup(&lookup_client, 15, 0, 0);
+
+	return 0;
+
+err_unregister_driver:
+	platform_driver_unregister(&qmi_sample_driver);
+err_remove_debug_dir:
+	debugfs_remove(qmi_debug_dir);
+
+	return ret;
+}
+
+static void qmi_sample_exit(void)
+{
+	qmi_handle_release(&lookup_client);
+
+	platform_driver_unregister(&qmi_sample_driver);
+
+	debugfs_remove(qmi_debug_dir);
+}
+
+module_init(qmi_sample_init);
+module_exit(qmi_sample_exit);
+
+MODULE_DESCRIPTION("Sample QMI client driver");
+MODULE_LICENSE("GPL v2");
-- 
2.15.0

Re: [PATCH v2 2/5] soc: qcom: Introduce QMI helpers

[Arun Kumar Neelakantam]

On 11/7/2017 10:50 AM, Bjorn Andersson wrote:
> Drivers that needs to communicate with a remote QMI service all has to
> perform the operations of discovering the service, encoding and decoding
> the messages and operate the socket. This introduces an abstraction for
> these common operations, reducing most of the duplication in such cases.
>
> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> ---
>
> Changes since v1:
> - Squashed notion of qmi vs qrtr in interface, to simplify client code
> - Lookup and service registration is cached and handled by core on ENETRESET
> - Introduce callbacks for BYE and DEL_CLIENT control messages
> - Revisited locking for socket and transaction objects, squashed a few races
>    and made it possible to send "indication" messages from message handlers.
> - kerneldoc updates
> - Moved handling of net_reset from clients to this code, greatly simplifies
>    typical drivers and reduces duplication
> - Pass transaction id of QMI message to handlers even though it's not a
>    response, allows sending a response with the txn id of an incoming request.
> - Split qmi_send_message() in three, instead of passing type as parameter - to
>    clean up handling of "indication" messages.
>
>   drivers/soc/qcom/Kconfig         |   1 +
>   drivers/soc/qcom/Makefile        |   1 +
>   drivers/soc/qcom/qmi_interface.c | 849 +++++++++++++++++++++++++++++++++++++++
>   include/linux/soc/qcom/qmi.h     | 157 ++++++++
>   4 files changed, 1008 insertions(+)
>   create mode 100644 drivers/soc/qcom/qmi_interface.c
>
> diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
> index 91b70b170a82..9718f1c41e3d 100644
> --- a/drivers/soc/qcom/Kconfig
> +++ b/drivers/soc/qcom/Kconfig
> @@ -37,6 +37,7 @@ config QCOM_PM
>   
>   config QCOM_QMI_HELPERS
>   	tristate
> +	depends on ARCH_QCOM
I feel It should depend on QRTR instead of ARCH_QCOM
>   	help
>   	  Helper library for handling QMI encoded messages.  QMI encoded
>   	  messages are used in communication between the majority of QRTR
> diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
> index 625750acfeef..b04b5044775f 100644
> --- a/drivers/soc/qcom/Makefile
> +++ b/drivers/soc/qcom/Makefile
> @@ -4,6 +4,7 @@ obj-$(CONFIG_QCOM_MDT_LOADER)	+= mdt_loader.o
>   obj-$(CONFIG_QCOM_PM)	+=	spm.o
>   obj-$(CONFIG_QCOM_QMI_HELPERS)	+= qmi_helpers.o
>   qmi_helpers-y	+= qmi_encdec.o
> +qmi_helpers-y	+= qmi_interface.o
>   obj-$(CONFIG_QCOM_SMD_RPM)	+= smd-rpm.o
>   obj-$(CONFIG_QCOM_SMEM) +=	smem.o
>   obj-$(CONFIG_QCOM_SMEM_STATE) += smem_state.o
> diff --git a/drivers/soc/qcom/qmi_interface.c b/drivers/soc/qcom/qmi_interface.c
> new file mode 100644
> index 000000000000..d7885f9b072b
> --- /dev/null
> +++ b/drivers/soc/qcom/qmi_interface.c
> @@ -0,0 +1,849 @@
> +/*
> + * Copyright (C) 2017 Linaro Ltd.
> + *
> + * This software is licensed under the terms of the GNU General Public
> + * License version 2, as published by the Free Software Foundation, and
> + * may be copied, distributed, and modified under those terms.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/device.h>
> +#include <linux/platform_device.h>
> +#include <linux/qrtr.h>
> +#include <linux/net.h>
> +#include <linux/completion.h>
> +#include <linux/idr.h>
> +#include <linux/string.h>
> +#include <net/sock.h>
> +#include <linux/workqueue.h>
> +#include <linux/soc/qcom/qmi.h>
> +
> +static struct socket *qmi_sock_create(struct qmi_handle *qmi,
> +				      struct sockaddr_qrtr *sq);
> +
> +/**
> + * qmi_recv_new_server() - handler of NEW_SERVER control message
> + * @qmi:	qmi handle
> + * @node:	node of the new server
> + * @port:	port of the new server
> + *
> + * Calls the new_server callback to inform the client about a newly registered
> + * server matching the currently registered service lookup.
> + */
> +static void qmi_recv_new_server(struct qmi_handle *qmi,
> +				   unsigned int service, unsigned int instance,
> +				   unsigned int node, unsigned int port)
> +{
> +	struct qmi_ops *ops = &qmi->ops;
> +	struct qmi_service *svc;
> +	int ret;
> +
> +	if (!ops->new_server)
> +		return;
> +
> +	/* Ignore EOF marker */
> +	if (!node && !port)
> +		return;
> +
> +	svc = kzalloc(sizeof(*svc), GFP_KERNEL);
> +	if (!svc)
> +		return;
> +
> +	svc->service = service;
> +	svc->version = instance & 0xff;
> +	svc->instance = instance >> 8;
> +	svc->node = node;
> +	svc->port = port;
> +
> +	ret = ops->new_server(qmi, svc);
> +	if (ret < 0)
> +		kfree(svc);
> +	else
> +		list_add(&svc->list_node, &qmi->lookup_results);
> +}
> +
> +/**
> + * qmi_recv_del_server() - handler of DEL_SERVER control message
> + * @qmi:	qmi handle
> + * @node:	node of the dying server, a value of -1 matches all nodes
> + * @port:	port of the dying server, a value of -1 matches all ports
> + *
> + * Calls the del_server callback for each previously seen server, allowing the
> + * client to react to the disappearing server.
> + */
> +static void qmi_recv_del_server(struct qmi_handle *qmi,
> +				   unsigned int node, unsigned int port)
> +{
> +	struct qmi_ops *ops = &qmi->ops;
> +	struct qmi_service *svc;
> +	struct qmi_service *tmp;
> +
> +	list_for_each_entry_safe(svc, tmp, &qmi->lookup_results, list_node) {
> +		if (node != -1 && svc->node != node)
> +			continue;
> +		if (port != -1 && svc->port != port)
> +			continue;
> +
> +		if (ops->del_server)
> +			ops->del_server(qmi, svc);
> +
> +		list_del(&svc->list_node);
> +		kfree(svc);
> +	}
> +}
> +
> +/**
> + * qmi_recv_bye() - handler of BYE control message
> + * @qmi:	qmi handle
> + * @node:	id of the dying node
> + *
> + * Signals the client that all previously registered services on this node are
> + * now gone and then calls the bye callback to allow the client client further
> + * cleaning up resources associated with this remote.
> + */
> +static void qmi_recv_bye(struct qmi_handle *qmi,
> +			    unsigned int node)
> +{
> +	struct qmi_ops *ops = &qmi->ops;
> +
> +	qmi_recv_del_server(qmi, node, -1);
> +
> +	if (ops->bye)
> +		ops->bye(qmi, node);
> +}
> +
> +/**
> + * qmi_recv_del_client() - handler of DEL_CLIENT control message
> + * @qmi:	qmi handle
> + * @node:	node of the dying client
> + * @port:	port of the dying client
> + *
> + * Signals the client about a dying client, by calling the del_client callback.
> + */
> +static void qmi_recv_del_client(struct qmi_handle *qmi,
> +				   unsigned int node, unsigned int port)
> +{
> +	struct qmi_ops *ops = &qmi->ops;
> +
> +	if (ops->del_client)
> +		ops->del_client(qmi, node, port);
> +}
> +
> +static void qmi_recv_ctrl_pkt(struct qmi_handle *qmi,
> +				 const void *buf, size_t len)
> +{
> +	const struct qrtr_ctrl_pkt *pkt = buf;
> +
> +	if (len < sizeof(struct qrtr_ctrl_pkt)) {
> +		pr_debug("ignoring short control packet\n");
> +		return;
> +	}
> +
> +	switch (le32_to_cpu(pkt->cmd)) {
> +	case QRTR_TYPE_BYE:
> +		qmi_recv_bye(qmi, le32_to_cpu(pkt->client.node));
> +		break;
> +	case QRTR_TYPE_NEW_SERVER:
> +		qmi_recv_new_server(qmi,
> +				    le32_to_cpu(pkt->server.service),
> +				    le32_to_cpu(pkt->server.instance),
> +				    le32_to_cpu(pkt->server.node),
> +				    le32_to_cpu(pkt->server.port));
> +		break;
> +	case QRTR_TYPE_DEL_SERVER:
> +		qmi_recv_del_server(qmi,
> +				    le32_to_cpu(pkt->server.node),
> +				    le32_to_cpu(pkt->server.port));
> +		break;
> +	case QRTR_TYPE_DEL_CLIENT:
> +		qmi_recv_del_client(qmi,
> +				    le32_to_cpu(pkt->client.node),
> +				    le32_to_cpu(pkt->client.port));
> +		break;
> +	}
> +}
> +
> +static void qmi_send_new_lookup(struct qmi_handle *qmi, struct qmi_service *svc)
> +{
> +	struct qrtr_ctrl_pkt pkt;
> +	struct sockaddr_qrtr sq;
> +	struct msghdr msg = {0};
> +	struct kvec iv = { &pkt, sizeof(pkt) };
> +	int ret;
> +
> +	memset(&pkt, 0, sizeof(pkt));
> +	pkt.cmd = cpu_to_le32(QRTR_TYPE_NEW_LOOKUP);
> +	pkt.server.service = cpu_to_le32(svc->service);
> +	pkt.server.instance = cpu_to_le32(svc->version | svc->instance << 8);
> +
> +	sq.sq_family = qmi->sq.sq_family;
> +	sq.sq_node = qmi->sq.sq_node;
> +	sq.sq_port = QRTR_PORT_CTRL;
> +
> +	msg.msg_name = &sq;
> +	msg.msg_namelen = sizeof(sq);
> +
> +	mutex_lock(&qmi->sock_lock);
> +	if (qmi->sock) {
> +		ret = kernel_sendmsg(qmi->sock, &msg, &iv, 1, sizeof(pkt));
> +		if (ret < 0)
> +			pr_err("failed to send lookup registration: %d\n", ret);
> +	}
> +	mutex_unlock(&qmi->sock_lock);
> +}
> +
> +/**
> + * qmi_add_lookup() - register a new lookup with the name service
> + * @qmi:	qmi handle
> + * @service:	service id of the request
> + * @instance:	instance id of the request
> + *
> + * Returns 0 on success, negative errno on failure.
> + *
> + * Registering a lookup query with the name server will cause the name server
> + * to send NEW_SERVER and DEL_SERVER control messages to this socket as
> + * matching services are registered.
> + */
> +int qmi_add_lookup(struct qmi_handle *qmi, unsigned int service,
> +		   unsigned int version, unsigned int instance)
> +{
> +	struct qmi_service *svc;
> +
> +	svc = kzalloc(sizeof(*svc), GFP_KERNEL);
> +	if (!svc)
> +		return -ENOMEM;
> +
> +	svc->service = service;
> +	svc->version = version;
> +	svc->instance = instance;
> +
> +	list_add(&svc->list_node, &qmi->lookups);
> +
> +	qmi_send_new_lookup(qmi, svc);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(qmi_add_lookup);
> +
> +static void qmi_send_new_server(struct qmi_handle *qmi, struct qmi_service *svc)
> +{
> +	struct qrtr_ctrl_pkt pkt;
> +	struct sockaddr_qrtr sq;
> +	struct msghdr msg = {0};
> +	struct kvec iv = { &pkt, sizeof(pkt) };
> +	int ret;
> +
> +	memset(&pkt, 0, sizeof(pkt));
> +	pkt.cmd = cpu_to_le32(QRTR_TYPE_NEW_SERVER);
> +	pkt.server.service = cpu_to_le32(svc->service);
> +	pkt.server.instance = cpu_to_le32(svc->version | svc->instance << 8);
> +	pkt.server.node = qmi->sq.sq_node;
> +	pkt.server.port = qmi->sq.sq_port;
> +
> +	sq.sq_family = qmi->sq.sq_family;
> +	sq.sq_node = qmi->sq.sq_node;
> +	sq.sq_port = QRTR_PORT_CTRL;
> +
> +	msg.msg_name = &sq;
> +	msg.msg_namelen = sizeof(sq);
> +
> +	mutex_lock(&qmi->sock_lock);
> +	if (qmi->sock) {
> +		ret = kernel_sendmsg(qmi->sock, &msg, &iv, 1, sizeof(pkt));
This NEW_SERVER message is send to name server then it will be 
broadcasted to all nodes in network by name server right.
> +		if (ret < 0)
> +			pr_err("failed to send service registration: %d\n", ret);
> +	}
> +	mutex_unlock(&qmi->sock_lock);
> +}
> +
> +/**
> + * qmi_add_server() - register a service with the name service
> + * @qmi:	qmi handle
> + * @service:	type of the service
> + * @instance:	instance of the service
> + *
> + * Returns 0 on success, negative errno on failure.
> + *
> + * Register a new service with the name service. This allows clients to find
> + * and start sending messages to the client associated with @qmi.
> + */
> +int qmi_add_server(struct qmi_handle *qmi, unsigned int service,
> +		   unsigned int version, unsigned int instance)
> +{
> +	struct qmi_service *svc;
> +
> +	svc = kzalloc(sizeof(*svc), GFP_KERNEL);
> +	if (!svc)
> +		return -ENOMEM;
> +
> +	svc->service = service;
> +	svc->version = version;
> +	svc->instance = instance;
> +
> +	list_add(&svc->list_node, &qmi->services);
> +
> +	qmi_send_new_server(qmi, svc);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(qmi_add_server);
> +
> +/**
> + * qmi_txn_init() - allocate transaction id within the given QMI handle
> + * @qmi:	QMI handle
> + * @txn:	transaction context
> + * @ei:		description of how to decode a matching response (optional)
> + * @c_struct:	pointer to the object to decode the response into (optional)
> + *
> + * Returns transaction id on success, negative errno on failure.
> + *
> + * This allocates a transaction id within the QMI handle. If @ei and @c_struct
> + * are specified any responses to this transaction will be decoded as described
> + * by @ei into @c_struct.
> + *
> + * A client calling qmi_txn_init() must call either qmi_txn_wait() or
> + * qmi_txn_cancel() to free up the allocated resources.
> + */
> +int qmi_txn_init(struct qmi_handle *qmi, struct qmi_txn *txn,
> +		 struct qmi_elem_info *ei, void *c_struct)
> +{
> +	int ret;
> +
> +	memset(txn, 0, sizeof(*txn));
> +
> +	mutex_init(&txn->lock);
> +	init_completion(&txn->completion);
> +	txn->qmi = qmi;
> +	txn->ei = ei;
> +	txn->dest = c_struct;
> +
> +	mutex_lock(&qmi->txn_lock);
> +	ret = idr_alloc_cyclic(&qmi->txns, txn, 0, INT_MAX, GFP_KERNEL);
> +	if (ret < 0)
> +		pr_err("failed to allocate transaction id\n");
> +
> +	txn->id = ret;
> +	mutex_unlock(&qmi->txn_lock);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(qmi_txn_init);
> +
> +/**
> + * qmi_txn_wait() - wait for a response on a transaction
> + * @txn:	transaction handle
> + * @timeout:	timeout, in jiffies
> + *
> + * Returns the transaction response on success, negative errno on failure.
> + *
> + * If the transaction is decoded by the means of @ei and @c_struct the return
> + * value will be the returned value of qmi_decode_message(), otherwise it's up
> + * to the specified message handler to fill out the result.
> + */
> +int qmi_txn_wait(struct qmi_txn *txn, unsigned long timeout)
> +{
> +	struct qmi_handle *qmi = txn->qmi;
> +	int ret;
> +
> +	ret = wait_for_completion_interruptible_timeout(&txn->completion,
> +							timeout);
> +
> +	mutex_lock(&qmi->txn_lock);
> +	mutex_lock(&txn->lock);
> +	idr_remove(&qmi->txns, txn->id);
> +	mutex_unlock(&txn->lock);
> +	mutex_unlock(&qmi->txn_lock);
> +
> +	if (ret < 0)
> +		return ret;
> +	else if (ret == 0)
> +		return -ETIMEDOUT;
> +	else
> +		return txn->result;
> +}
> +EXPORT_SYMBOL_GPL(qmi_txn_wait);
> +
> +/**
> + * qmi_txn_cancel() - cancel an ongoing transaction
> + * @txn:	transaction id
> + */
> +void qmi_txn_cancel(struct qmi_txn *txn)
> +{
> +	struct qmi_handle *qmi = txn->qmi;
> +
> +	mutex_lock(&qmi->txn_lock);
> +	mutex_lock(&txn->lock);
> +	idr_remove(&qmi->txns, txn->id);
> +	mutex_unlock(&txn->lock);
> +	mutex_unlock(&qmi->txn_lock);
> +}
> +EXPORT_SYMBOL_GPL(qmi_txn_cancel);
> +
> +/**
> + * qmi_invoke_handler() - find and invoke a handler for a message
> + * @qmi:	qmi handle
> + * @sq:		sockaddr of the sender
> + * @txn:	transaction object for the message
> + * @buf:	buffer containing the message
> + * @len:	length of @buf
> + *
> + * Find handler and invoke handler for the incoming message.
> + */
> +static void qmi_invoke_handler(struct qmi_handle *qmi, struct sockaddr_qrtr *sq,
> +			       struct qmi_txn *txn, const void *buf, size_t len)
> +{
> +	struct qmi_msg_handler *handler;
> +	const struct qmi_header *hdr = buf;
> +	void *dest;
> +	int ret;
> +
> +	if (!qmi->handlers)
> +		return;
> +
> +	for (handler = qmi->handlers; handler->fn; handler++) {
> +		if (handler->type == hdr->type &&
> +		    handler->msg_id == hdr->msg_id)
> +			break;
> +	}
> +
> +	if (!handler->fn)
> +		return;
> +
> +	dest = kzalloc(handler->decoded_size, GFP_KERNEL);
> +	if (!dest)
> +		return;
> +
> +	ret = qmi_decode_message(buf, len, handler->ei, dest);
> +	if (ret < 0)
> +		pr_err("failed to decode incoming message\n");
> +	else
> +		handler->fn(qmi, sq, txn, dest);
> +
> +	kfree(dest);
> +}
> +
> +/**
> + * qmi_handle_net_reset() - invoked to handle ENETRESET on a QMI handle
> + * @qmi:	the QMI context
> + *
> + * As a result of registering a name service with the QRTR all open sockets are
> + * flagged with ENETRESET and this function will be called. The typical case is
> + * the initial boot, where this signals that the local node id has been
> + * configured and as such any bound sockets needs to be rebound. So close the
> + * socket, inform the client and re-initialize the socket.
> + *
> + * For clients it's generally sufficient to react to the del_server callbacks,
> + * but server code is expected to treat the net_reset callback as a "bye" from
> + * all nodes.
> + *
> + * Finally the QMI handle will send out registration requests for any lookups
> + * and services.
> + */
> +static void qmi_handle_net_reset(struct qmi_handle *qmi)
> +{
> +	struct sockaddr_qrtr sq;
> +	struct qmi_service *svc;
> +	struct socket *sock;
> +
> +	sock = qmi_sock_create(qmi, &sq);
> +	if (IS_ERR(sock))
> +		return;
> +
> +	mutex_lock(&qmi->sock_lock);
> +	sock_release(qmi->sock);
> +	qmi->sock = NULL;
> +	mutex_unlock(&qmi->sock_lock);
> +
> +	qmi_recv_del_server(qmi, -1, -1);
> +
> +	if (qmi->ops.net_reset)
> +		qmi->ops.net_reset(qmi);
> +
> +	mutex_lock(&qmi->sock_lock);
> +	qmi->sock = sock;
> +	qmi->sq = sq;
> +	mutex_unlock(&qmi->sock_lock);
> +
> +	list_for_each_entry(svc, &qmi->lookups, list_node)
> +		qmi_send_new_lookup(qmi, svc);
> +
> +	list_for_each_entry(svc, &qmi->services, list_node)
> +		qmi_send_new_server(qmi, svc);
> +}
> +
> +static void qmi_handle_message(struct qmi_handle *qmi,
> +			       struct sockaddr_qrtr *sq,
> +			       const void *buf, size_t len)
> +{
> +	const struct qmi_header *hdr;
> +	struct qmi_txn tmp_txn;
> +	struct qmi_txn *txn = NULL;
> +	int ret;
> +
> +	if (len < sizeof(*hdr)) {
> +		pr_err("ignoring short QMI packet\n");
> +		return;
> +	}
> +
> +	hdr = buf;
> +
> +	/* If this is a response, find the matching transaction handle */
> +	if (hdr->type == QMI_RESPONSE) {
> +		mutex_lock(&qmi->txn_lock);
> +		txn = idr_find(&qmi->txns, hdr->txn_id);
> +		if (txn)
> +			mutex_lock(&txn->lock);
> +		mutex_unlock(&qmi->txn_lock);
> +	}
> +
> +	if (txn && txn->dest && txn->ei) {
> +		ret = qmi_decode_message(buf, len, txn->ei, txn->dest);
> +		if (ret < 0)
> +			pr_err("failed to decode incoming message\n");
> +
> +		txn->result = ret;
> +		complete(&txn->completion);
> +
> +		mutex_unlock(&txn->lock);
> +	} else if (txn) {
> +		qmi_invoke_handler(qmi, sq, txn, buf, len);
> +
> +		mutex_unlock(&txn->lock);
> +	} else {
> +		/* Create a txn based on the txn_id of the incoming message */
> +		memset(&tmp_txn, 0, sizeof(tmp_txn));
> +		tmp_txn.id = hdr->txn_id;
> +
> +		qmi_invoke_handler(qmi, sq, &tmp_txn, buf, len);
> +	}
> +}
> +
> +static void qmi_data_ready_work(struct work_struct *work)
> +{
> +	struct qmi_handle *qmi = container_of(work, struct qmi_handle, work);
> +	struct qmi_ops *ops = &qmi->ops;
> +	struct sockaddr_qrtr sq;
> +	struct msghdr msg = { .msg_name = &sq, .msg_namelen = sizeof(sq) };
> +	struct kvec iv;
> +	ssize_t msglen;
> +
> +	for (;;) {
> +		iv.iov_base = qmi->recv_buf;
> +		iv.iov_len = qmi->recv_buf_size;
> +
> +		mutex_lock(&qmi->sock_lock);
> +		if (qmi->sock)
> +			msglen = kernel_recvmsg(qmi->sock, &msg, &iv, 1,
> +						iv.iov_len, MSG_DONTWAIT);
> +		else
> +			msglen = -EPIPE;
> +		mutex_unlock(&qmi->sock_lock);
> +		if (msglen == -EAGAIN)
> +			break;
> +
> +		if (msglen == -ENETRESET) {
> +			qmi_handle_net_reset(qmi);
> +
> +			/* The old qmi->sock is gone, our work is done */
> +			break;
> +		}
> +
> +		if (msglen < 0) {
> +			pr_err("qmi recvmsg failed: %zd\n", msglen);
> +			break;
> +		}
> +
> +		if (sq.sq_node == qmi->sq.sq_node &&
> +		    sq.sq_port == QRTR_PORT_CTRL) {
> +			qmi_recv_ctrl_pkt(qmi, qmi->recv_buf, msglen);
> +		} else if (ops->msg_handler) {
> +			ops->msg_handler(qmi, &sq, qmi->recv_buf, msglen);
> +		} else {
> +			qmi_handle_message(qmi, &sq, qmi->recv_buf, msglen);
> +		}
> +	}
> +}
> +
> +static void qmi_data_ready(struct sock *sk)
> +{
> +	struct qmi_handle *qmi = sk->sk_user_data;
> +
> +	/*
> +	 * This will be NULL if we receive data while being in
> +	 * qmi_handle_release()
> +	 */
> +	if (!qmi)
> +		return;
> +
> +	queue_work(qmi->wq, &qmi->work);
> +}
> +
> +static struct socket *qmi_sock_create(struct qmi_handle *qmi,
> +				      struct sockaddr_qrtr *sq)
> +{
> +	struct socket *sock;
> +	int sl = sizeof(*sq);
> +	int ret;
> +
> +	ret = sock_create_kern(&init_net, AF_QIPCRTR, SOCK_DGRAM,
> +			       PF_QIPCRTR, &sock);
> +	if (ret < 0)
> +		return ERR_PTR(ret);
> +
> +	ret = kernel_getsockname(sock, (struct sockaddr *)sq, &sl);
> +	if (ret < 0) {
> +		sock_release(sock);
> +		return ERR_PTR(ret);
> +	}
> +
> +	sock->sk->sk_user_data = qmi;
> +	sock->sk->sk_data_ready = qmi_data_ready;
> +	sock->sk->sk_error_report = qmi_data_ready;
> +
> +	return sock;
> +}
> +
> +/**
> + * qmi_handle_init() - initialize a QMI client handle
> + * @qmi:	QMI handle to initialize
> + * @max_msg_len: maximum size of incoming message
> + * @handlers:	NULL-terminated list of QMI message handlers
> + *
> + * Returns 0 on success, negative errno on failure.
> + *
> + * This initializes the QMI client handle to allow sending and receiving QMI
> + * messages. As messages are received the appropriate handler will be invoked.
> + */
> +int qmi_handle_init(struct qmi_handle *qmi, size_t recv_buf_size,
> +		    struct qmi_ops *ops, struct qmi_msg_handler *handlers)
> +{
> +	int ret;
> +
> +	mutex_init(&qmi->txn_lock);
> +	mutex_init(&qmi->sock_lock);
> +
> +	idr_init(&qmi->txns);
> +
> +	INIT_LIST_HEAD(&qmi->lookups);
> +	INIT_LIST_HEAD(&qmi->lookup_results);
> +	INIT_LIST_HEAD(&qmi->services);
> +
> +	INIT_WORK(&qmi->work, qmi_data_ready_work);
> +
> +	qmi->handlers = handlers;
> +	if (ops)
> +		qmi->ops = *ops;
> +
> +	if (recv_buf_size < sizeof(struct qrtr_ctrl_pkt))
> +		recv_buf_size = sizeof(struct qrtr_ctrl_pkt);
> +	else
> +		recv_buf_size += sizeof(struct qmi_header);
> +
> +	qmi->recv_buf_size = recv_buf_size;
> +	qmi->recv_buf = kzalloc(recv_buf_size, GFP_KERNEL);
> +	if (!qmi->recv_buf)
> +		return -ENOMEM;
> +
> +	qmi->wq = alloc_workqueue("qmi_msg_handler", WQ_UNBOUND, 1);
> +	if (!qmi->wq) {
> +		ret = -ENOMEM;
> +		goto err_free_recv_buf;
> +	}
> +
> +	qmi->sock = qmi_sock_create(qmi, &qmi->sq);
> +	if (IS_ERR(qmi->sock)) {
> +		pr_err("failed to create QMI socket\n");
> +		ret = PTR_ERR(qmi->sock);
> +		goto err_destroy_wq;
> +	}
> +
> +	return 0;
> +
> +err_destroy_wq:
> +	destroy_workqueue(qmi->wq);
> +err_free_recv_buf:
> +	kfree(qmi->recv_buf);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(qmi_handle_init);
> +
> +/**
> + * qmi_handle_release() - release the QMI client handle
> + * @qmi:	QMI client handle
> + *
> + * This closes the underlying socket and stops any handling of QMI messages.
> + */
> +void qmi_handle_release(struct qmi_handle *qmi)
> +{
> +	struct socket *sock = qmi->sock;
> +	struct qmi_service *svc, *tmp;
> +
> +	sock->sk->sk_user_data = NULL;
> +	cancel_work_sync(&qmi->work);
> +
> +	qmi_recv_del_server(qmi, -1, -1);
> +
> +	mutex_lock(&qmi->sock_lock);
> +	sock_release(sock);
> +	qmi->sock = NULL;
> +	mutex_unlock(&qmi->sock_lock);
> +
> +	destroy_workqueue(qmi->wq);
> +
> +	idr_destroy(&qmi->txns);
> +
> +	kfree(qmi->recv_buf);
> +
> +	/* Free registered lookup requests */
> +	list_for_each_entry_safe(svc, tmp, &qmi->lookups, list_node) {
> +		list_del(&svc->list_node);
> +		kfree(svc);
> +	}
> +
> +	/* Free registered service information */
> +	list_for_each_entry_safe(svc, tmp, &qmi->services, list_node) {
> +		list_del(&svc->list_node);
> +		kfree(svc);
> +	}
> +}
> +EXPORT_SYMBOL_GPL(qmi_handle_release);
> +
> +/**
> + * qmi_send_message() - send a QMI message
> + * @qmi:	QMI client handle
> + * @sq:		destination sockaddr
> + * @txn:	transaction object to use for the message
> + * @type:	type of message to send
> + * @msg_id:	message id
> + * @len:	max length of the QMI message
> + * @ei:		QMI message description
> + * @c_struct:	object to be encoded
> + *
> + * Returns 0 on success, negative errno on failure.
> + *
> + * This function encodes @c_struct using @ei into a message of type @type,
> + * with @msg_id and @txn into a buffer of maximum size @len, and sends this to
> + * @sq.
> + */
> +static ssize_t qmi_send_message(struct qmi_handle *qmi,
> +				struct sockaddr_qrtr *sq, struct qmi_txn *txn,
> +				int type, int msg_id, size_t len,
> +				struct qmi_elem_info *ei, const void *c_struct)
> +{
> +	struct msghdr msghdr = {0};
> +	struct kvec iv;
> +	void *msg;
> +	int ret;
> +
> +	msg = qmi_encode_message(type,
> +				 msg_id, &len,
> +				 txn->id, ei,
> +				 c_struct);
> +	if (IS_ERR(msg))
> +		return PTR_ERR(msg);
> +
> +	iv.iov_base = msg;
> +	iv.iov_len = len;
> +
> +	if (sq) {
> +		msghdr.msg_name = sq;
> +		msghdr.msg_namelen = sizeof(*sq);
> +	}
> +
> +	mutex_lock(&qmi->sock_lock);
> +	if (qmi->sock) {
> +		ret = kernel_sendmsg(qmi->sock, &msghdr, &iv, 1, len);
> +		if (ret < 0)
> +			pr_err("failed to send QMI message\n");
> +	} else {
> +		ret = -EPIPE;
> +	}
> +	mutex_unlock(&qmi->sock_lock);
> +
> +	kfree(msg);
> +
> +	return ret < 0 ? ret : 0;
> +}
> +
> +/**
> + * qmi_send_indication() - send a request QMI message
Look incorrect function name is used
> + * @qmi:	QMI client handle
> + * @sq:		destination sockaddr
> + * @txn:	transaction object to use for the message
> + * @msg_id:	message id
> + * @len:	max length of the QMI message
> + * @ei:		QMI message description
> + * @c_struct:	object to be encoded
> + *
> + * Returns 0 on success, negative errno on failure.
> + */
> +ssize_t qmi_send_request(struct qmi_handle *qmi, struct sockaddr_qrtr *sq,
> +			 struct qmi_txn *txn, int msg_id, size_t len,
> +			 struct qmi_elem_info *ei, const void *c_struct)
> +{
> +	return qmi_send_message(qmi, sq, txn, QMI_REQUEST, msg_id, len, ei,
> +				c_struct);
> +}
> +EXPORT_SYMBOL_GPL(qmi_send_request);
> +
> +/**
> + * qmi_send_indication() - send a response QMI message
Look incorrect function name is used
> + * @qmi:	QMI client handle
> + * @sq:		destination sockaddr
> + * @txn:	transaction object to use for the message
> + * @msg_id:	message id
> + * @len:	max length of the QMI message
> + * @ei:		QMI message description
> + * @c_struct:	object to be encoded
> + *
> + * Returns 0 on success, negative errno on failure.
> + */
> +ssize_t qmi_send_response(struct qmi_handle *qmi, struct sockaddr_qrtr *sq,
> +			  struct qmi_txn *txn, int msg_id, size_t len,
> +			  struct qmi_elem_info *ei, const void *c_struct)
> +{
> +	return qmi_send_message(qmi, sq, txn, QMI_RESPONSE, msg_id, len, ei,
> +				c_struct);
> +}
> +EXPORT_SYMBOL_GPL(qmi_send_response);
> +
> +/**
> + * qmi_send_indication() - send an indication QMI message
> + * @qmi:	QMI client handle
> + * @sq:		destination sockaddr
> + * @txn:	transaction object to use for the message
> + * @msg_id:	message id
> + * @len:	max length of the QMI message
> + * @ei:		QMI message description
> + * @c_struct:	object to be encoded
> + *
> + * Returns 0 on success, negative errno on failure.
> + */
> +ssize_t qmi_send_indication(struct qmi_handle *qmi, struct sockaddr_qrtr *sq,
> +			    int msg_id, size_t len, struct qmi_elem_info *ei,
> +			    const void *c_struct)
> +{
> +	struct qmi_txn txn;
> +	ssize_t rval;
> +	int ret;
> +
> +	ret = qmi_txn_init(qmi, &txn, NULL, NULL);
> +	if (ret < 0)
> +		return ret;;
> +
> +	rval = qmi_send_message(qmi, sq, &txn, QMI_INDICATION, msg_id, len, ei,
> +				c_struct);
> +
> +	/* We don't care about future messages on this txn */
> +	qmi_txn_cancel(&txn);
> +
> +	return rval;
> +}
> +EXPORT_SYMBOL_GPL(qmi_send_indication);
> diff --git a/include/linux/soc/qcom/qmi.h b/include/linux/soc/qcom/qmi.h
> index 804d2232c55b..1aedc8f14ec2 100644
> --- a/include/linux/soc/qcom/qmi.h
> +++ b/include/linux/soc/qcom/qmi.h
> @@ -105,6 +105,159 @@ struct qmi_response_type_v01 {
>   
>   extern struct qmi_elem_info qmi_response_type_v01_ei[];
>   
> +/**
> + * struct qmi_service - context to track lookup-results
> + * @service:	service type
> + * @version:	version of the @service
> + * @instance:	instance id of the @service
> + * @node:	node of the service
> + * @port:	port of the service
> + * @priv:	handle for client's use
> + * @list_node:	list_head for house keeping
> + */
> +struct qmi_service {
> +	unsigned int service;
> +	unsigned int version;
> +	unsigned int instance;
> +
> +	unsigned int node;
> +	unsigned int port;
> +
> +	void *priv;
> +	struct list_head list_node;
> +};
> +
> +struct qmi_handle;
> +
> +/**
> + * struct qmi_ops - callbacks for qmi_handle
> + * @new_server:		inform client of a new_server lookup-result, returning
> + *                      successfully from this call causes the library to call
> + *                      @del_server as the service is removed from the
> + *                      lookup-result. @priv of the qmi_service can be used by
> + *                      the client
> + * @del_server:		inform client of a del_server lookup-result
> + * @net_reset:		inform client that the name service was restarted and
> + *                      that and any state needs to be released
> + * @msg_handler:	invoked for incoming messages, allows a client to
> + *                      override the usual QMI message handler
> + * @bye:                inform a client that all clients from a node are gone
> + * @del_client:         inform a client that a particular client is gone
> + */
> +struct qmi_ops {
> +	int (*new_server)(struct qmi_handle *qmi, struct qmi_service *svc);
> +	void (*del_server)(struct qmi_handle *qmi, struct qmi_service *svc);
> +	void (*net_reset)(struct qmi_handle *qmi);
> +	void (*msg_handler)(struct qmi_handle *qmi, struct sockaddr_qrtr *sq,
> +			    const void *data, size_t count);
> +	void (*bye)(struct qmi_handle *qmi, unsigned int node);
> +	void (*del_client)(struct qmi_handle *qmi,
> +			   unsigned int node, unsigned int port);
> +};
> +
> +
> +/**
> + * struct qmi_txn - transaction context
> + * @qmi:	QMI handle this transaction is associated with
> + * @id:		transaction id
> + * @lock:	for synchronization between handler and waiter of messages
> + * @completion:	completion object as the transaction receives a response
> + * @result:	result code for the completed transaction
> + * @ei:		description of the QMI encoded response (optional)
> + * @dest:	destination buffer to decode message into (optional)
> + */
> +struct qmi_txn {
> +	struct qmi_handle *qmi;
> +
> +	int id;
> +
> +	struct mutex lock;
> +	struct completion completion;
> +	int result;
> +
> +	struct qmi_elem_info *ei;
> +	void *dest;
> +};
> +
> +/**
> + * struct qmi_msg_handler - description of QMI message handler
> + * @type:	type of message
> + * @msg_id:	message id
> + * @ei:		description of the QMI encoded message
> + * @decoded_size:	size of the decoded object
> + * @fn:		function to invoke as the message is decoded
> + */
> +struct qmi_msg_handler {
> +	unsigned int type;
> +	unsigned int msg_id;
> +
> +	struct qmi_elem_info *ei;
> +
> +	size_t decoded_size;
> +	void (*fn)(struct qmi_handle *qmi, struct sockaddr_qrtr *sq,
> +		   struct qmi_txn *txn, const void *decoded);
> +};
> +
> +/**
> + * struct qmi_handle - QMI context
> + * @sock:	socket handle
> + * @sock_lock:	synchronization of @sock modifications
> + * @sq:		sockaddr of @sock
> + * @work:	work for handling incoming messages
> + * @wq:		workqueue to post @work on
> + * @recv_buf:	scratch buffer for handling incoming messages
> + * @recv_buf_size:	size of @recv_buf
> + * @lookups:		list of registered lookup requests
> + * @lookup_results:	list of lookup-results advertised to the client
> + * @services:		list of registered services (by this client)
> + * @ops:	reference to callbacks
> + * @txns:	outstanding transactions
> + * @txn_lock:	lock for modifications of @txns
> + * @handlers:	list of handlers for incoming messages
> + */
> +struct qmi_handle {
> +	struct socket *sock;
> +	struct mutex sock_lock;
> +
> +	struct sockaddr_qrtr sq;
> +
> +	struct work_struct work;
> +	struct workqueue_struct *wq;
> +
> +	void *recv_buf;
> +	size_t recv_buf_size;
> +
> +	struct list_head lookups;
> +	struct list_head lookup_results;
> +	struct list_head services;
> +
> +	struct qmi_ops ops;
> +
> +	struct idr txns;
> +	struct mutex txn_lock;
> +
> +	struct qmi_msg_handler *handlers;
> +};
> +
> +int qmi_add_lookup(struct qmi_handle *qmi, unsigned int service,
> +		   unsigned int version, unsigned int instance);
> +int qmi_add_server(struct qmi_handle *qmi, unsigned int service,
> +		   unsigned int version, unsigned int instance);
> +
> +int qmi_handle_init(struct qmi_handle *qmi, size_t max_msg_len,
> +		    struct qmi_ops *ops, struct qmi_msg_handler *handlers);
> +void qmi_handle_release(struct qmi_handle *qmi);
> +
> +ssize_t qmi_send_request(struct qmi_handle *qmi, struct sockaddr_qrtr *sq,
> +			 struct qmi_txn *txn, int msg_id, size_t len,
> +			 struct qmi_elem_info *ei, const void *c_struct);
> +ssize_t qmi_send_response(struct qmi_handle *qmi, struct sockaddr_qrtr *sq,
> +			  struct qmi_txn *txn, int msg_id, size_t len,
> +			  struct qmi_elem_info *ei, const void *c_struct);
> +ssize_t qmi_send_indication(struct qmi_handle *qmi, struct sockaddr_qrtr *sq,
> +			    int msg_id, size_t len, struct qmi_elem_info *ei,
> +			    const void *c_struct);
> +
>   void *qmi_encode_message(int type, unsigned int msg_id, size_t *len,
>   			 unsigned int txn_id, struct qmi_elem_info *ei,
>   			 const void *c_struct);
> @@ -112,5 +265,9 @@ void *qmi_encode_message(int type, unsigned int msg_id, size_t *len,
>   int qmi_decode_message(const void *buf, size_t len,
>   		       struct qmi_elem_info *ei, void *c_struct);
>   
> +int qmi_txn_init(struct qmi_handle *qmi, struct qmi_txn *txn,
> +		 struct qmi_elem_info *ei, void *c_struct);
> +int qmi_txn_wait(struct qmi_txn *txn, unsigned long timeout);
> +void qmi_txn_cancel(struct qmi_txn *txn);
>   
>   #endif

Re: [PATCH v2 5/5] samples: Introduce Qualcomm QMI sample client

[Jonathan Neuschäfer]

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Hi, some small comments below.

On Mon, Nov 06, 2017 at 09:20:42PM -0800, Bjorn Andersson wrote:
> Introduce a sample driver that register for server notifications and
> spawn clients for each available test service (service 15). The spawned
> clients implements the interface for encoding "ping" and "data" requests
> and decode the responses from the remote.
> 
> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> ---
[...]
> +/*
> + * ping_pong_store() - ping_pong debugfs file write handler

The function name is ping_write now.

> + * @file:	debugfs file context
> + * @user_buf:	reference to the user data
> + * @count:	number of bytes in @user_buf
> + * @ppos:	offset in @file to write
> + *
> + * Returns @count, or negative errno on failure.
> + *
> + * This function allows user space to send out a ping_pong QMI encoded message
> + * to the associated remote test service and will return with the result of the
> + * transaction. It serves as an example of how to provide a custom response
> + * handler.
> + */
> +static ssize_t ping_write(struct file *file, const char __user *user_buf,
> +			  size_t count, loff_t *ppos)

The data in user_buf is completely ignored, right? Perhaps that's worth
mentioning in the doc comment.

> +{
> +	struct qmi_handle *qmi = file->private_data;
> +	struct test_ping_req_msg_v01 req = {0};
> +	struct qmi_txn txn;
> +	int ret;
> +
> +	memcpy(req.ping, "ping", sizeof(req.ping));
> +
> +	ret = qmi_txn_init(qmi, &txn, NULL, NULL);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = qmi_send_request(qmi, NULL, &txn,
> +			       TEST_PING_REQ_MSG_ID_V01,
> +			       TEST_PING_REQ_MAX_MSG_LEN_V01,
> +			       test_ping_req_msg_v01_ei, &req);
> +	if (ret < 0) {
> +		qmi_txn_cancel(&txn);
> +		return ret;
> +	}
> +
> +	ret = qmi_txn_wait(&txn, 5 * HZ);
> +	if (ret < 0)
> +		count = ret;
> +
> +	return count;
> +}
[...]
> +
> +/*
> + * data_store() - data debugfs file write handler

data_write

> + * @file:	debugfs file context
> + * @user_buf:	reference to the user data
> + * @count:	number of bytes in @user_buf
> + * @ppos:	offset in @file to write
> + *
> + * Returns @count, or negative errno on failure.
> + *
> + * This function allows user space to send out a data QMI encoded message to
> + * the associated remote test service and will return with the result of the
> + * transaction. It serves as an example of how to have the QMI helpers decode a
> + * transaction response into a provided object automatically.
> + */
> +static ssize_t data_write(struct file *file, const char __user *user_buf,
> +			  size_t count, loff_t *ppos)



Jonathan Neuschäfer

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Re: [PATCH v2 5/5] samples: Introduce Qualcomm QMI sample client

[Bjorn Andersson]

On Tue 07 Nov 10:40 PST 2017, Jonathan Neusch?fer wrote:

> Hi, some small comments below.
> 

Hi Jonathan,

Thanks for proof reading, I will correct these things.

Regards,
Bjorn

Re: [PATCH v2 2/5] soc: qcom: Introduce QMI helpers

[Bjorn Andersson]

On Tue 07 Nov 08:27 PST 2017, Arun Kumar Neelakantam wrote:
> On 11/7/2017 10:50 AM, Bjorn Andersson wrote:
> > diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
> > index 91b70b170a82..9718f1c41e3d 100644
> > --- a/drivers/soc/qcom/Kconfig
> > +++ b/drivers/soc/qcom/Kconfig
> > @@ -37,6 +37,7 @@ config QCOM_PM
> >   config QCOM_QMI_HELPERS
> >   	tristate
> > +	depends on ARCH_QCOM
> I feel It should depend on QRTR instead of ARCH_QCOM

make currently skips drivers/soc/qcom when ARCH_QCOM is not set (Kbuild
doesn't), so this "depends on" ensures that anyone selecting this will
get a "unmet dependency" warning from Kbuild if they don't also depends
on ARCH_QCOM.

Not specifying a dependency on QRTR does increase build test coverage
somewhat, but as we're still limited by ARCH_QCOM it's not that big of a
gain. So I'll add this, as you suggest.

[..]
> > diff --git a/drivers/soc/qcom/qmi_interface.c b/drivers/soc/qcom/qmi_interface.c
[..]
> > +static void qmi_send_new_server(struct qmi_handle *qmi, struct qmi_service *svc)
> > +{
> > +	struct qrtr_ctrl_pkt pkt;
> > +	struct sockaddr_qrtr sq;
> > +	struct msghdr msg = {0};
> > +	struct kvec iv = { &pkt, sizeof(pkt) };
> > +	int ret;
> > +
> > +	memset(&pkt, 0, sizeof(pkt));
> > +	pkt.cmd = cpu_to_le32(QRTR_TYPE_NEW_SERVER);
> > +	pkt.server.service = cpu_to_le32(svc->service);
> > +	pkt.server.instance = cpu_to_le32(svc->version | svc->instance << 8);
> > +	pkt.server.node = qmi->sq.sq_node;
> > +	pkt.server.port = qmi->sq.sq_port;
> > +
> > +	sq.sq_family = qmi->sq.sq_family;
> > +	sq.sq_node = qmi->sq.sq_node;
> > +	sq.sq_port = QRTR_PORT_CTRL;
> > +
> > +	msg.msg_name = &sq;
> > +	msg.msg_namelen = sizeof(sq);
> > +
> > +	mutex_lock(&qmi->sock_lock);
> > +	if (qmi->sock) {
> > +		ret = kernel_sendmsg(qmi->sock, &msg, &iv, 1, sizeof(pkt));
> This NEW_SERVER message is send to name server then it will be broadcasted
> to all nodes in network by name server right.

Correct, above you can see that I use the sq_node of our socket as
destination node and QRTR_PORT_CTRL.

The name service will forward the information about the new service to
any registered nodes and will keep track of it and advertise it to
future appearing nodes.

[..]
> > +/**
> > + * qmi_send_indication() - send a request QMI message
> Look incorrect function name is used

Yes, a copy-paste error of mine. Will fix.

> > + * @qmi:	QMI client handle
> > + * @sq:		destination sockaddr
> > + * @txn:	transaction object to use for the message
> > + * @msg_id:	message id
> > + * @len:	max length of the QMI message
> > + * @ei:		QMI message description
> > + * @c_struct:	object to be encoded
> > + *
> > + * Returns 0 on success, negative errno on failure.
> > + */
> > +ssize_t qmi_send_request(struct qmi_handle *qmi, struct sockaddr_qrtr *sq,
> > +			 struct qmi_txn *txn, int msg_id, size_t len,
> > +			 struct qmi_elem_info *ei, const void *c_struct)
> > +{
> > +	return qmi_send_message(qmi, sq, txn, QMI_REQUEST, msg_id, len, ei,
> > +				c_struct);
> > +}
> > +EXPORT_SYMBOL_GPL(qmi_send_request);
> > +
> > +/**
> > + * qmi_send_indication() - send a response QMI message
> Look incorrect function name is used

Dito.

Thank you,
Bjorn

Re: [PATCH v2 2/5] soc: qcom: Introduce QMI helpers

[Chris Lew]

Hi Bjorn,

Found a minor typo.

On 11/6/2017 9:20 PM, Bjorn Andersson wrote:

[..]
> +ssize_t qmi_send_indication(struct qmi_handle *qmi, struct sockaddr_qrtr *sq,
> +			    int msg_id, size_t len, struct qmi_elem_info *ei,
> +			    const void *c_struct)
> +{
> +	struct qmi_txn txn;
> +	ssize_t rval;
> +	int ret;
> +
> +	ret = qmi_txn_init(qmi, &txn, NULL, NULL);
> +	if (ret < 0)
> +		return ret;;

Double semi colon on ret.

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