cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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smd-rpm.c (6920B)


      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * Copyright (c) 2015, Sony Mobile Communications AB.
      4 * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
      5 */
      6
      7#include <linux/module.h>
      8#include <linux/platform_device.h>
      9#include <linux/of_platform.h>
     10#include <linux/io.h>
     11#include <linux/interrupt.h>
     12#include <linux/slab.h>
     13
     14#include <linux/rpmsg.h>
     15#include <linux/soc/qcom/smd-rpm.h>
     16
     17#define RPM_REQUEST_TIMEOUT     (5 * HZ)
     18
     19/**
     20 * struct qcom_smd_rpm - state of the rpm device driver
     21 * @rpm_channel:	reference to the smd channel
     22 * @icc:		interconnect proxy device
     23 * @dev:		rpm device
     24 * @ack:		completion for acks
     25 * @lock:		mutual exclusion around the send/complete pair
     26 * @ack_status:		result of the rpm request
     27 */
     28struct qcom_smd_rpm {
     29	struct rpmsg_endpoint *rpm_channel;
     30	struct platform_device *icc;
     31	struct device *dev;
     32
     33	struct completion ack;
     34	struct mutex lock;
     35	int ack_status;
     36};
     37
     38/**
     39 * struct qcom_rpm_header - header for all rpm requests and responses
     40 * @service_type:	identifier of the service
     41 * @length:		length of the payload
     42 */
     43struct qcom_rpm_header {
     44	__le32 service_type;
     45	__le32 length;
     46};
     47
     48/**
     49 * struct qcom_rpm_request - request message to the rpm
     50 * @msg_id:	identifier of the outgoing message
     51 * @flags:	active/sleep state flags
     52 * @type:	resource type
     53 * @id:		resource id
     54 * @data_len:	length of the payload following this header
     55 */
     56struct qcom_rpm_request {
     57	__le32 msg_id;
     58	__le32 flags;
     59	__le32 type;
     60	__le32 id;
     61	__le32 data_len;
     62};
     63
     64/**
     65 * struct qcom_rpm_message - response message from the rpm
     66 * @msg_type:	indicator of the type of message
     67 * @length:	the size of this message, including the message header
     68 * @msg_id:	message id
     69 * @message:	textual message from the rpm
     70 *
     71 * Multiple of these messages can be stacked in an rpm message.
     72 */
     73struct qcom_rpm_message {
     74	__le32 msg_type;
     75	__le32 length;
     76	union {
     77		__le32 msg_id;
     78		u8 message[0];
     79	};
     80};
     81
     82#define RPM_SERVICE_TYPE_REQUEST	0x00716572 /* "req\0" */
     83
     84#define RPM_MSG_TYPE_ERR		0x00727265 /* "err\0" */
     85#define RPM_MSG_TYPE_MSG_ID		0x2367736d /* "msg#" */
     86
     87/**
     88 * qcom_rpm_smd_write - write @buf to @type:@id
     89 * @rpm:	rpm handle
     90 * @state:	active/sleep state flags
     91 * @type:	resource type
     92 * @id:		resource identifier
     93 * @buf:	the data to be written
     94 * @count:	number of bytes in @buf
     95 */
     96int qcom_rpm_smd_write(struct qcom_smd_rpm *rpm,
     97		       int state,
     98		       u32 type, u32 id,
     99		       void *buf,
    100		       size_t count)
    101{
    102	static unsigned msg_id = 1;
    103	int left;
    104	int ret;
    105	struct {
    106		struct qcom_rpm_header hdr;
    107		struct qcom_rpm_request req;
    108		u8 payload[];
    109	} *pkt;
    110	size_t size = sizeof(*pkt) + count;
    111
    112	/* SMD packets to the RPM may not exceed 256 bytes */
    113	if (WARN_ON(size >= 256))
    114		return -EINVAL;
    115
    116	pkt = kmalloc(size, GFP_KERNEL);
    117	if (!pkt)
    118		return -ENOMEM;
    119
    120	mutex_lock(&rpm->lock);
    121
    122	pkt->hdr.service_type = cpu_to_le32(RPM_SERVICE_TYPE_REQUEST);
    123	pkt->hdr.length = cpu_to_le32(sizeof(struct qcom_rpm_request) + count);
    124
    125	pkt->req.msg_id = cpu_to_le32(msg_id++);
    126	pkt->req.flags = cpu_to_le32(state);
    127	pkt->req.type = cpu_to_le32(type);
    128	pkt->req.id = cpu_to_le32(id);
    129	pkt->req.data_len = cpu_to_le32(count);
    130	memcpy(pkt->payload, buf, count);
    131
    132	ret = rpmsg_send(rpm->rpm_channel, pkt, size);
    133	if (ret)
    134		goto out;
    135
    136	left = wait_for_completion_timeout(&rpm->ack, RPM_REQUEST_TIMEOUT);
    137	if (!left)
    138		ret = -ETIMEDOUT;
    139	else
    140		ret = rpm->ack_status;
    141
    142out:
    143	kfree(pkt);
    144	mutex_unlock(&rpm->lock);
    145	return ret;
    146}
    147EXPORT_SYMBOL(qcom_rpm_smd_write);
    148
    149static int qcom_smd_rpm_callback(struct rpmsg_device *rpdev,
    150				 void *data,
    151				 int count,
    152				 void *priv,
    153				 u32 addr)
    154{
    155	const struct qcom_rpm_header *hdr = data;
    156	size_t hdr_length = le32_to_cpu(hdr->length);
    157	const struct qcom_rpm_message *msg;
    158	struct qcom_smd_rpm *rpm = dev_get_drvdata(&rpdev->dev);
    159	const u8 *buf = data + sizeof(struct qcom_rpm_header);
    160	const u8 *end = buf + hdr_length;
    161	char msgbuf[32];
    162	int status = 0;
    163	u32 len, msg_length;
    164
    165	if (le32_to_cpu(hdr->service_type) != RPM_SERVICE_TYPE_REQUEST ||
    166	    hdr_length < sizeof(struct qcom_rpm_message)) {
    167		dev_err(rpm->dev, "invalid request\n");
    168		return 0;
    169	}
    170
    171	while (buf < end) {
    172		msg = (struct qcom_rpm_message *)buf;
    173		msg_length = le32_to_cpu(msg->length);
    174		switch (le32_to_cpu(msg->msg_type)) {
    175		case RPM_MSG_TYPE_MSG_ID:
    176			break;
    177		case RPM_MSG_TYPE_ERR:
    178			len = min_t(u32, ALIGN(msg_length, 4), sizeof(msgbuf));
    179			memcpy_fromio(msgbuf, msg->message, len);
    180			msgbuf[len - 1] = 0;
    181
    182			if (!strcmp(msgbuf, "resource does not exist"))
    183				status = -ENXIO;
    184			else
    185				status = -EINVAL;
    186			break;
    187		}
    188
    189		buf = PTR_ALIGN(buf + 2 * sizeof(u32) + msg_length, 4);
    190	}
    191
    192	rpm->ack_status = status;
    193	complete(&rpm->ack);
    194	return 0;
    195}
    196
    197static int qcom_smd_rpm_probe(struct rpmsg_device *rpdev)
    198{
    199	struct qcom_smd_rpm *rpm;
    200	int ret;
    201
    202	rpm = devm_kzalloc(&rpdev->dev, sizeof(*rpm), GFP_KERNEL);
    203	if (!rpm)
    204		return -ENOMEM;
    205
    206	mutex_init(&rpm->lock);
    207	init_completion(&rpm->ack);
    208
    209	rpm->dev = &rpdev->dev;
    210	rpm->rpm_channel = rpdev->ept;
    211	dev_set_drvdata(&rpdev->dev, rpm);
    212
    213	rpm->icc = platform_device_register_data(&rpdev->dev, "icc_smd_rpm", -1,
    214						 NULL, 0);
    215	if (IS_ERR(rpm->icc))
    216		return PTR_ERR(rpm->icc);
    217
    218	ret = of_platform_populate(rpdev->dev.of_node, NULL, NULL, &rpdev->dev);
    219	if (ret)
    220		platform_device_unregister(rpm->icc);
    221
    222	return ret;
    223}
    224
    225static void qcom_smd_rpm_remove(struct rpmsg_device *rpdev)
    226{
    227	struct qcom_smd_rpm *rpm = dev_get_drvdata(&rpdev->dev);
    228
    229	platform_device_unregister(rpm->icc);
    230	of_platform_depopulate(&rpdev->dev);
    231}
    232
    233static const struct of_device_id qcom_smd_rpm_of_match[] = {
    234	{ .compatible = "qcom,rpm-apq8084" },
    235	{ .compatible = "qcom,rpm-ipq6018" },
    236	{ .compatible = "qcom,rpm-msm8226" },
    237	{ .compatible = "qcom,rpm-msm8916" },
    238	{ .compatible = "qcom,rpm-msm8936" },
    239	{ .compatible = "qcom,rpm-msm8953" },
    240	{ .compatible = "qcom,rpm-msm8974" },
    241	{ .compatible = "qcom,rpm-msm8976" },
    242	{ .compatible = "qcom,rpm-msm8994" },
    243	{ .compatible = "qcom,rpm-msm8996" },
    244	{ .compatible = "qcom,rpm-msm8998" },
    245	{ .compatible = "qcom,rpm-sdm660" },
    246	{ .compatible = "qcom,rpm-sm6115" },
    247	{ .compatible = "qcom,rpm-sm6125" },
    248	{ .compatible = "qcom,rpm-qcm2290" },
    249	{ .compatible = "qcom,rpm-qcs404" },
    250	{}
    251};
    252MODULE_DEVICE_TABLE(of, qcom_smd_rpm_of_match);
    253
    254static struct rpmsg_driver qcom_smd_rpm_driver = {
    255	.probe = qcom_smd_rpm_probe,
    256	.remove = qcom_smd_rpm_remove,
    257	.callback = qcom_smd_rpm_callback,
    258	.drv  = {
    259		.name  = "qcom_smd_rpm",
    260		.of_match_table = qcom_smd_rpm_of_match,
    261	},
    262};
    263
    264static int __init qcom_smd_rpm_init(void)
    265{
    266	return register_rpmsg_driver(&qcom_smd_rpm_driver);
    267}
    268arch_initcall(qcom_smd_rpm_init);
    269
    270static void __exit qcom_smd_rpm_exit(void)
    271{
    272	unregister_rpmsg_driver(&qcom_smd_rpm_driver);
    273}
    274module_exit(qcom_smd_rpm_exit);
    275
    276MODULE_AUTHOR("Bjorn Andersson <bjorn.andersson@sonymobile.com>");
    277MODULE_DESCRIPTION("Qualcomm SMD backed RPM driver");
    278MODULE_LICENSE("GPL v2");