Merge tag 'qcom-drivers-for-4.16' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/agross/linux into next/drivers

Pull "Qualcomm ARM Based Driver Updates for v4.16 - Redo" from Andy Gross:

* Fix error handling code in SMP2P probe
* Update SMP2P to use ACPS as mailbox client
* Add QMI support
* Fixups for Qualcomm SCM
* Fix licensing on rmtfs_mem
* Correct SMSM child node lookup
* Populate firmware nodes during platform init

* tag 'qcom-drivers-for-4.16' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/agross/linux:
  of: platform: populate /firmware/ node from of_platform_default_populate_init()
  soc: qcom: smp2p: Use common error handling code in qcom_smp2p_probe()
  soc: qcom: Introduce QMI helpers
  soc: qcom: Introduce QMI encoder/decoder
  firmware: qcom_scm: Add dependent headers to qcom_scm.h
  soc: qcom: smp2p: Access APCS as mailbox client
  soc: qcom: rmtfs_mem: add missing MODULE_DESCRIPTION/AUTHOR/LICENSE
  soc: qcom: smsm: fix child-node lookup
  firmware: qcom_scm: drop redandant of_platform_populate

Documentation/devicetree/bindings/soc/qcom/qcom,smp2p.txt

@@ -17,9 +17,15 @@ processor ID) and a string identifier.
 	Value type: <prop-encoded-array>
 	Definition: one entry specifying the smp2p notification interrupt
 
-- qcom,ipc:
+- mboxes:
 	Usage: required
 	Value type: <prop-encoded-array>
+	Definition: reference to the associated doorbell in APCS, as described
+		    in mailbox/mailbox.txt
+
+- qcom,ipc:
+	Usage: required, unless mboxes is specified
+	Value type: <prop-encoded-array>
 	Definition: three entries specifying the outgoing ipc bit used for
 		    signaling the remote end of the smp2p edge:
 		    - phandle to a syscon node representing the apcs registers

drivers/firmware/qcom_scm.c

@@ -622,30 +622,6 @@ static struct platform_driver qcom_scm_driver = {
 
 static int __init qcom_scm_init(void)
 {
-	struct device_node *np, *fw_np;
-	int ret;
-
-	fw_np = of_find_node_by_name(NULL, "firmware");
-
-	if (!fw_np)
-		return -ENODEV;
-
-	np = of_find_matching_node(fw_np, qcom_scm_dt_match);
-
-	if (!np) {
-		of_node_put(fw_np);
-		return -ENODEV;
-	}
-
-	of_node_put(np);
-
-	ret = of_platform_populate(fw_np, qcom_scm_dt_match, NULL, NULL);
-
-	of_node_put(fw_np);
-
-	if (ret)
-		return ret;
-
 	return platform_driver_register(&qcom_scm_driver);
 }
 subsys_initcall(qcom_scm_init);

drivers/of/platform.c

@@ -518,6 +518,10 @@ static int __init of_platform_default_populate_init(void)
 	for_each_matching_node(node, reserved_mem_matches)
 		of_platform_device_create(node, NULL, NULL);
 
+	node = of_find_node_by_path("/firmware");
+	if (node)
+		of_platform_populate(node, NULL, NULL, NULL);
+
 	/* Populate everything else. */
 	of_platform_default_populate(NULL, NULL, NULL);
 

drivers/soc/qcom/Kconfig

@@ -35,6 +35,15 @@ config QCOM_PM
 	  modes. It interface with various system drivers to put the cores in
 	  low power modes.
 
+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
+	  clients and this helpers provide the common functionality needed for
+	  doing this from a kernel driver.
+
 config QCOM_RMTFS_MEM
 	tristate "Qualcomm Remote Filesystem memory driver"
 	depends on ARCH_QCOM
@@ -75,6 +84,7 @@ config QCOM_SMEM_STATE
 
 config QCOM_SMP2P
 	tristate "Qualcomm Shared Memory Point to Point support"
+	depends on MAILBOX
 	depends on QCOM_SMEM
 	select QCOM_SMEM_STATE
 	help

drivers/soc/qcom/Makefile

@@ -3,6 +3,8 @@ 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-$(CONFIG_QCOM_QMI_HELPERS)	+= qmi_helpers.o
+qmi_helpers-y	+= qmi_encdec.o qmi_interface.o
 obj-$(CONFIG_QCOM_RMTFS_MEM)	+= rmtfs_mem.o
 obj-$(CONFIG_QCOM_SMD_RPM)	+= smd-rpm.o
 obj-$(CONFIG_QCOM_SMEM) +=	smem.o

drivers/soc/qcom/qmi_encdec.c

@@ -0,0 +1,816 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2012-2015, The Linux Foundation. All rights reserved.
+ * Copyright (C) 2017 Linaro Ltd.
+ */
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/errno.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++ = ((u8)((length) & 0xFF)); \
+	*p_dst++ = ((u8)(((length) >> 8) & 0xFF)); \
+} while (0)
+
+#define QMI_ENCDEC_DECODE_TLV(p_type, p_length, p_src) do { \
+	*p_type = (u8)*p_src++; \
+	*p_length = (u8)*p_src++; \
+	*p_length |= ((u8)*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 = (u8 *)p_dst + size; \
+	p_src = (u8 *)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 = (u8 *)p_dst + size; \
+	p_src = (u8 *)p_src + size; \
+} while (0)
+
+#define UPDATE_ENCODE_VARIABLES(temp_si, buf_dst, \
+				encoded_bytes, tlv_len, encode_tlv, rc) \
+do { \
+	buf_dst = (u8 *)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 = (u8 *)buf_src + rc; \
+	decoded_bytes += rc; \
+} while (0)
+
+#define TLV_LEN_SIZE sizeof(u16)
+#define TLV_TYPE_SIZE sizeof(u8)
+#define OPTIONAL_TLV_TYPE_START 0x10
+
+static int qmi_encode(struct qmi_elem_info *ei_array, void *out_buf,
+		      const void *in_c_struct, u32 out_buf_len,
+		      int enc_level);
+
+static int qmi_decode(struct qmi_elem_info *ei_array, void *out_c_struct,
+		      const void *in_buf, u32 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.
+ *
+ * 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.
+ *
+ * Return: struct info of the next element that can be encoded.
+ */
+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;
+	u8 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.
+ *
+ * Return: 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(u8) ?
+					sizeof(u8) : sizeof(u16));
+			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(u8) : sizeof(u16);
+			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.
+ *
+ * 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 u8 - u64 or similar. This
+ * function returns the number of bytes of encoded information.
+ *
+ * Return: The number of bytes of encoded information.
+ */
+static int qmi_encode_basic_elem(void *buf_dst, const void *buf_src,
+				 u32 elem_len, u32 elem_size)
+{
+	u32 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.
+ *
+ * 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.
+ *
+ * Return: The number of bytes of encoded information on success or negative
+ * errno on error.
+ */
+static int qmi_encode_struct_elem(struct qmi_elem_info *ei_array,
+				  void *buf_dst, const void *buf_src,
+				  u32 elem_len, u32 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.
+ *
+ * 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.
+ *
+ * Return: The number of bytes of encoded information on success or negative
+ * errno on error.
+ */
+static int qmi_encode_string_elem(struct qmi_elem_info *ei_array,
+				  void *buf_dst, const void *buf_src,
+				  u32 out_buf_len, int enc_level)
+{
+	int rc;
+	int encoded_bytes = 0;
+	struct qmi_elem_info *temp_ei = ei_array;
+	u32 string_len = 0;
+	u32 string_len_sz = 0;
+
+	string_len = strlen(buf_src);
+	string_len_sz = temp_ei->elem_len <= U8_MAX ?
+			sizeof(u8) : sizeof(u16);
+	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.
+ *
+ * Return: 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, u32 out_buf_len,
+		      int enc_level)
+{
+	struct qmi_elem_info *temp_ei = ei_array;
+	u8 opt_flag_value = 0;
+	u32 data_len_value = 0, data_len_sz;
+	u8 *buf_dst = (u8 *)out_buf;
+	u8 *tlv_pointer;
+	u32 tlv_len;
+	u8 tlv_type;
+	u32 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->array_type == NO_ARRAY) {
+			data_len_value = 1;
+		} else if (temp_ei->array_type == 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(u8));
+			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(u8) ?
+					sizeof(u8) : sizeof(u16);
+			/* 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.
+ *
+ * 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 u8 - u64 or similar. This
+ * function returns the number of bytes of decoded information.
+ *
+ * Return: The total size of the decoded data elements, in bytes.
+ */
+static int qmi_decode_basic_elem(void *buf_dst, const void *buf_src,
+				 u32 elem_len, u32 elem_size)
+{
+	u32 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.
+ *
+ * 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.
+ *
+ * Return: The total size of the decoded data elements on success, negative
+ * errno on error.
+ */
+static int qmi_decode_struct_elem(struct qmi_elem_info *ei_array,
+				  void *buf_dst, const void *buf_src,
+				  u32 elem_len, u32 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.
+ *
+ * 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.
+ *
+ * Return: The total size of the decoded data elements on success, negative
+ * errno on error.
+ */
+static int qmi_decode_string_elem(struct qmi_elem_info *ei_array,
+				  void *buf_dst, const void *buf_src,
+				  u32 tlv_len, int dec_level)
+{
+	int rc;
+	int decoded_bytes = 0;
+	u32 string_len = 0;
+	u32 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(u8) : sizeof(u16);
+		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.
+ *
+ * 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.
+ *
+ * Return: Pointer to struct info, if found
+ */
+static struct qmi_elem_info *find_ei(struct qmi_elem_info *ei_array,
+				     u32 type)
+{
+	struct qmi_elem_info *temp_ei = ei_array;
+
+	while (temp_ei->data_type != QMI_EOTI) {
+		if (temp_ei->tlv_type == (u8)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
+ *
+ * Return: 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, u32 in_buf_len,
+		      int dec_level)
+{
+	struct qmi_elem_info *temp_ei = ei_array;
+	u8 opt_flag_value = 1;
+	u32 data_len_value = 0, data_len_sz = 0;
+	u8 *buf_dst = out_c_struct;
+	const u8 *tlv_pointer;
+	u32 tlv_len = 0;
+	u32 tlv_type;
+	u32 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(u8));
+			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(u8) ?
+					sizeof(u8) : sizeof(u16);
+			rc = qmi_decode_basic_elem(&data_len_value, buf_src,
+						   1, data_len_sz);
+			memcpy(buf_dst, &data_len_value, sizeof(u32));
+			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->array_type == NO_ARRAY) {
+			data_len_value = 1;
+		} else if (temp_ei->array_type == 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
+ *
+ * Return: 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);
+		}
+	}
+
+	msg = kzalloc(sizeof(*hdr) + *len, GFP_KERNEL);
+	if (!msg)
+		return ERR_PTR(-ENOMEM);
+
+	/* Encode message, if we have a message */
+	if (c_struct) {
+		msglen = qmi_encode(ei, msg + sizeof(*hdr), c_struct, *len, 1);
+		if (msglen < 0) {
+			kfree(msg);
+			return ERR_PTR(msglen);
+		}
+	}
+
+	hdr = msg;
+	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
+ *
+ * Return: 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(u16),
+		.array_type	= 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(u16),
+		.array_type	= 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,
+		.array_type	= 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");

drivers/soc/qcom/qmi_interface.c

@@ -0,0 +1,848 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2017 Linaro Ltd.
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/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
+ * @service:	service id of the new server
+ * @instance:	instance id of the new server
+ * @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 = { };
+	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
+ * @version:	version number of the request
+ *
+ * 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.
+ *
+ * Return: 0 on success, negative errno on failure.
+ */
+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(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 = { };
+	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 = cpu_to_le32(qmi->sq.sq_node);
+	pkt.server.port = cpu_to_le32(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("send service registration failed: %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
+ * @version:	version of the service
+ *
+ * Register a new service with the name service. This allows clients to find
+ * and start sending messages to the client associated with @qmi.
+ *
+ * Return: 0 on success, negative errno on failure.
+ */
+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(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)
+ *
+ * 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.
+ *
+ * Return: Transaction id on success, negative errno on failure.
+ */
+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(qmi_txn_init);
+
+/**
+ * qmi_txn_wait() - wait for a response on a transaction
+ * @txn:	transaction handle
+ * @timeout:	timeout, in jiffies
+ *
+ * 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.
+ *
+ * Return: the transaction response on success, negative errno on failure.
+ */
+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(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(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)
+{
+	const 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);
+
+		/* Ignore unexpected responses */
+		if (!txn) {
+			mutex_unlock(&qmi->txn_lock);
+			return;
+		}
+
+		mutex_lock(&txn->lock);
+		mutex_unlock(&qmi->txn_lock);
+
+		if (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);
+		} else  {
+			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
+ * @recv_buf_size: maximum size of incoming message
+ * @ops:	reference to callbacks for QRTR notifications
+ * @handlers:	NULL-terminated list of QMI message handlers
+ *
+ * This initializes the QMI client handle to allow sending and receiving QMI
+ * messages. As messages are received the appropriate handler will be invoked.
+ *
+ * Return: 0 on success, negative errno on failure.
+ */
+int qmi_handle_init(struct qmi_handle *qmi, size_t recv_buf_size,
+		    const struct qmi_ops *ops,
+		    const 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(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(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
+ *
+ * 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.
+ *
+ * Return: 0 on success, negative errno on failure.
+ */
+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 = {};
+	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_request() - 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
+ *
+ * Return: 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(qmi_send_request);
+
+/**
+ * qmi_send_response() - 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
+ *
+ * Return: 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(qmi_send_response);
+
+/**
+ * qmi_send_indication() - send an indication QMI message
+ * @qmi:	QMI client handle
+ * @sq:		destination sockaddr
+ * @msg_id:	message id
+ * @len:	max length of the QMI message
+ * @ei:		QMI message description
+ * @c_struct:	object to be encoded
+ *
+ * Return: 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(qmi_send_indication);

drivers/soc/qcom/rmtfs_mem.c

@@ -267,3 +267,7 @@ static void qcom_rmtfs_mem_exit(void)
 	unregister_chrdev_region(qcom_rmtfs_mem_major, QCOM_RMTFS_MEM_DEV_MAX);
 }
 module_exit(qcom_rmtfs_mem_exit);
+
+MODULE_AUTHOR("Linaro Ltd");
+MODULE_DESCRIPTION("Qualcomm Remote Filesystem memory driver");
+MODULE_LICENSE("GPL v2");

drivers/soc/qcom/smp2p.c

@@ -18,6 +18,7 @@
 #include <linux/of.h>
 #include <linux/irq.h>
 #include <linux/irqdomain.h>
+#include <linux/mailbox_client.h>
 #include <linux/mfd/syscon.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
@@ -126,6 +127,8 @@ struct smp2p_entry {
  * @ipc_regmap:	regmap for the outbound ipc
  * @ipc_offset:	offset within the regmap
  * @ipc_bit:	bit in regmap@offset to kick to signal remote processor
+ * @mbox_client: mailbox client handle
+ * @mbox_chan:	apcs ipc mailbox channel handle
  * @inbound:	list of inbound entries
  * @outbound:	list of outbound entries
  */
@@ -146,6 +149,9 @@ struct qcom_smp2p {
 	int ipc_offset;
 	int ipc_bit;
 
+	struct mbox_client mbox_client;
+	struct mbox_chan *mbox_chan;
+
 	struct list_head inbound;
 	struct list_head outbound;
 };
@@ -154,7 +160,13 @@ static void qcom_smp2p_kick(struct qcom_smp2p *smp2p)
 {
 	/* Make sure any updated data is written before the kick */
 	wmb();
-	regmap_write(smp2p->ipc_regmap, smp2p->ipc_offset, BIT(smp2p->ipc_bit));
+
+	if (smp2p->mbox_chan) {
+		mbox_send_message(smp2p->mbox_chan, NULL);
+		mbox_client_txdone(smp2p->mbox_chan, 0);
+	} else {
+		regmap_write(smp2p->ipc_regmap, smp2p->ipc_offset, BIT(smp2p->ipc_bit));
+	}
 }
 
 /**
@@ -453,10 +465,6 @@ static int qcom_smp2p_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, smp2p);
 
-	ret = smp2p_parse_ipc(smp2p);
-	if (ret)
-		return ret;
-
 	key = "qcom,smem";
 	ret = of_property_read_u32_array(pdev->dev.of_node, key,
 					 smp2p->smem_items, 2);
@@ -465,17 +473,13 @@ static int qcom_smp2p_probe(struct platform_device *pdev)
 
 	key = "qcom,local-pid";
 	ret = of_property_read_u32(pdev->dev.of_node, key, &smp2p->local_pid);
-	if (ret < 0) {
-		dev_err(&pdev->dev, "failed to read %s\n", key);
-		return -EINVAL;
-	}
+	if (ret)
+		goto report_read_failure;
 
 	key = "qcom,remote-pid";
 	ret = of_property_read_u32(pdev->dev.of_node, key, &smp2p->remote_pid);
-	if (ret < 0) {
-		dev_err(&pdev->dev, "failed to read %s\n", key);
-		return -EINVAL;
-	}
+	if (ret)
+		goto report_read_failure;
 
 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0) {
@@ -483,9 +487,23 @@ static int qcom_smp2p_probe(struct platform_device *pdev)
 		return irq;
 	}
 
+	smp2p->mbox_client.dev = &pdev->dev;
+	smp2p->mbox_client.knows_txdone = true;
+	smp2p->mbox_chan = mbox_request_channel(&smp2p->mbox_client, 0);
+	if (IS_ERR(smp2p->mbox_chan)) {
+		if (PTR_ERR(smp2p->mbox_chan) != -ENODEV)
+			return PTR_ERR(smp2p->mbox_chan);
+
+		smp2p->mbox_chan = NULL;
+
+		ret = smp2p_parse_ipc(smp2p);
+		if (ret)
+			return ret;
+	}
+
 	ret = qcom_smp2p_alloc_outbound_item(smp2p);
 	if (ret < 0)
-		return ret;
+		goto release_mbox;
 
 	for_each_available_child_of_node(pdev->dev.of_node, node) {
 		entry = devm_kzalloc(&pdev->dev, sizeof(*entry), GFP_KERNEL);
@@ -540,7 +558,14 @@ unwind_interfaces:
 
 	smp2p->out->valid_entries = 0;
 
+release_mbox:
+	mbox_free_channel(smp2p->mbox_chan);
+
 	return ret;
+
+report_read_failure:
+	dev_err(&pdev->dev, "failed to read %s\n", key);
+	return -EINVAL;
 }
 
 static int qcom_smp2p_remove(struct platform_device *pdev)
@@ -554,6 +579,8 @@ static int qcom_smp2p_remove(struct platform_device *pdev)
 	list_for_each_entry(entry, &smp2p->outbound, node)
 		qcom_smem_state_unregister(entry->state);
 
+	mbox_free_channel(smp2p->mbox_chan);
+
 	smp2p->out->valid_entries = 0;
 
 	return 0;

drivers/soc/qcom/smsm.c

@@ -496,8 +496,10 @@ static int qcom_smsm_probe(struct platform_device *pdev)
 	if (!smsm->hosts)
 		return -ENOMEM;
 
-	local_node = of_find_node_with_property(of_node_get(pdev->dev.of_node),
-						"#qcom,smem-state-cells");
+	for_each_child_of_node(pdev->dev.of_node, local_node) {
+		if (of_find_property(local_node, "#qcom,smem-state-cells", NULL))
+			break;
+	}
 	if (!local_node) {
 		dev_err(&pdev->dev, "no state entry\n");
 		return -EINVAL;

include/linux/qcom_scm.h

@@ -13,6 +13,9 @@
 #ifndef __QCOM_SCM_H
 #define __QCOM_SCM_H
 
+#include <linux/types.h>
+#include <linux/cpumask.h>
+
 #define QCOM_SCM_VERSION(major, minor)	(((major) << 16) | ((minor) & 0xFF))
 #define QCOM_SCM_CPU_PWR_DOWN_L2_ON	0x0
 #define QCOM_SCM_CPU_PWR_DOWN_L2_OFF	0x1

include/linux/soc/qcom/qmi.h

@@ -0,0 +1,271 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2012-2014, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2017, Linaro Ltd.
+ */
+#ifndef __QMI_HELPERS_H__
+#define __QMI_HELPERS_H__
+
+#include <linux/completion.h>
+#include <linux/idr.h>
+#include <linux/list.h>
+#include <linux/qrtr.h>
+#include <linux/types.h>
+#include <linux/workqueue.h>
+
+struct socket;
+
+/**
+ * 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 {
+	u8 type;
+	u16 txn_id;
+	u16 msg_id;
+	u16 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.
+ * @array_type:	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;
+	u32 elem_len;
+	u32 elem_size;
+	enum qmi_array_type array_type;
+	u8 tlv_type;
+	u32 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[];
+
+/**
+ * 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;
+
+	const 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,
+		    const struct qmi_ops *ops,
+		    const 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);
+
+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