soc: qcom: add microdump collector

       obj-y += subsystem_notif.o

       obj-y += subsystem_restart.o

       obj-y += ramdump.o

       obj-y += microdump_collector.o

endif

obj-$(CONFIG_QCOM_EUD) += eud.o

obj-$(CONFIG_QSEE_IPC_IRQ) += qsee_ipc_irq.o

/* SPDX-License-Identifier: GPL-2.0

 * Copyright (c) 2018, The Linux Foundation. All rights reserved.

 */

#include <linux/init.h>

#include <linux/module.h>

#include <linux/slab.h>

#include <soc/qcom/subsystem_notif.h>

#include <soc/qcom/ramdump.h>

#include <linux/soc/qcom/smem.h>

#define SMEM_SSR_REASON_MSS0	421

#define SMEM_SSR_DATA_MSS0	611

#define SMEM_MODEM	1

/*

 * This program collects the data from SMEM regions whenever the modem crashes

 * and stores it in /dev/ramdump_microdump_modem so as to expose it to

 * user space.

 */

struct microdump_data {

	struct ramdump_device *microdump_dev;

	void *microdump_modem_notify_handler;

	struct notifier_block microdump_modem_ssr_nb;

};

static struct microdump_data *drv;

static int microdump_modem_notifier_nb(struct notifier_block *nb,

		unsigned long code, void *data)

{

	int ret = 0;

	size_t size_reason = 0, size_data = 0;

	char *crash_reason = NULL;

	char *crash_data = NULL;

	struct ramdump_segment segment[2];

	if (SUBSYS_RAMDUMP_NOTIFICATION != code && SUBSYS_SOC_RESET != code)

		return NOTIFY_OK;

	memset(segment, 0, sizeof(segment));

	crash_reason = qcom_smem_get(QCOM_SMEM_HOST_ANY

				, SMEM_SSR_REASON_MSS0, &size_reason);

	if (IS_ERR_OR_NULL(crash_reason)) {

		pr_info("%s: smem %d not available\n",

				__func__, SMEM_SSR_REASON_MSS0);

		goto out;

	}

	segment[0].v_address = crash_reason;

	segment[0].size = size_reason;

	crash_data = qcom_smem_get(SMEM_MODEM

				, SMEM_SSR_DATA_MSS0, &size_data);

	if (IS_ERR_OR_NULL(crash_data)) {

		pr_info("%s: smem %d not available\n",

				__func__, SMEM_SSR_DATA_MSS0);

		goto out;

	}

	segment[1].v_address = crash_data;

	segment[1].size = size_data;

	ret = do_ramdump(drv->microdump_dev, segment, 2);

	if (ret)

		pr_info("%s: do_ramdump() failed\n", __func__);

out:

	return NOTIFY_OK;

}

static int microdump_modem_ssr_register_notifier(struct microdump_data *drv)

{

	int ret = 0;

	drv->microdump_modem_ssr_nb.notifier_call = microdump_modem_notifier_nb;

	drv->microdump_modem_notify_handler =

		subsys_notif_register_notifier("modem",

			&drv->microdump_modem_ssr_nb);

	if (IS_ERR(drv->microdump_modem_notify_handler)) {

		pr_err("Modem register notifier failed: %ld\n",

			PTR_ERR(drv->microdump_modem_notify_handler));

		ret = -EINVAL;

	}

	return ret;

}

static void microdump_modem_ssr_unregister_notifier(struct microdump_data *drv)

{

	subsys_notif_unregister_notifier(drv->microdump_modem_notify_handler,

					&drv->microdump_modem_ssr_nb);

	drv->microdump_modem_notify_handler = NULL;

}

/*

 * microdump_init() - Registers kernel module for microdump collector

 *

 * Creates device file /dev/ramdump_microdump_modem and registers handler for

 * modem SSR events.

 *

 * Returns 0 on success and negative error code in case of errors

 */

static int __init microdump_init(void)

{

	int ret = -ENOMEM;

	drv = kzalloc(sizeof(struct microdump_data), GFP_KERNEL);

	if (!drv)

		goto out;

	drv->microdump_dev = create_ramdump_device("microdump_modem", NULL);

	if (!drv->microdump_dev) {

		pr_err("%s: Unable to create a microdump_modem ramdump device\n"

			, __func__);

		ret = -ENODEV;

		goto out_kfree;

	}

	ret = microdump_modem_ssr_register_notifier(drv);

	if (ret) {

		destroy_ramdump_device(drv->microdump_dev);

		goto out_kfree;

	}

	return ret;

out_kfree:

	pr_err("%s: Failed to register microdump collector\n", __func__);

	kfree(drv);

	drv = NULL;

out:

	return ret;

}

static void __exit microdump_exit(void)

{

	microdump_modem_ssr_unregister_notifier(drv);

	destroy_ramdump_device(drv->microdump_dev);

	kfree(drv);

}

module_init(microdump_init);

module_exit(microdump_exit);

MODULE_DESCRIPTION("Microdump Collector");

MODULE_LICENSE("GPL v2");