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Commit 6d74baa2 authored by Sujeev Dias's avatar Sujeev Dias
Browse files

mhi: devices: satellite: add option to defer initialization 



Add option to defer MHI satellite driver initialization due to
missing memory carve-outs in TZ as it can lead to access
control violations and crashes. Instead expose a debugfs entry
to initialize it.

CRs-Fixed: 2361053
Change-Id: I94c92a1f67d257481424ff9ed54bd3cba2f6c9bf
Acked-by: default avatarBhaumik Vasav Bhatt <bbhatt@qti.qualcomm.com>
Signed-off-by: default avatarTony Truong <truong@codeaurora.org>
Signed-off-by: default avatarSujeev Dias <sdias@codeaurora.org>
parent 4e5ff1ff

drivers/bus/mhi/devices/mhi_satellite.c

+58 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only

/* Copyright (c) 2019, The Linux Foundation. All rights reserved.*/



#include <linux/debugfs.h>

#include <linux/device.h>

#include <linux/dma-direction.h>

#include <linux/dma-mapping.h>
@@ -18,6 +19,8 @@ 


#define MHI_SAT_DRIVER_NAME "mhi_satellite"



static bool mhi_sat_defer_init = true; /* set by default */



/* logging macros */

#define IPC_LOG_PAGES (10)

#define IPC_LOG_LVL (MHI_MSG_LVL_INFO)
@@ -282,6 +285,9 @@ struct mhi_sat_driver { 


	struct mhi_sat_subsys *subsys; /* pointer to subsystem array */

	unsigned int num_subsys;



	struct dentry *dentry; /* debugfs directory */

	bool deferred_init_done; /* flag for deferred init protection */

};



static struct mhi_sat_driver mhi_sat_driver;
@@ -1041,6 +1047,44 @@ static struct mhi_driver mhi_sat_dev_driver = { 
	},

};



int mhi_sat_trigger_init(void *data, u64 val)

{

	struct mhi_sat_subsys *subsys;

	int i, ret;



	if (mhi_sat_driver.deferred_init_done)

		return -EIO;



	ret = register_rpmsg_driver(&mhi_sat_rpmsg_driver);

	if (ret)

		goto error_sat_trigger_init;



	ret = mhi_driver_register(&mhi_sat_dev_driver);

	if (ret)

		goto error_sat_trigger_register;



	mhi_sat_driver.deferred_init_done = true;



	return 0;



error_sat_trigger_register:

	unregister_rpmsg_driver(&mhi_sat_rpmsg_driver);



error_sat_trigger_init:

	subsys = mhi_sat_driver.subsys;

	for (i = 0; i < mhi_sat_driver.num_subsys; i++, subsys++) {

		ipc_log_context_destroy(subsys->ipc_log);

		mutex_destroy(&subsys->cntrl_mutex);

	}

	kfree(mhi_sat_driver.subsys);

	mhi_sat_driver.subsys = NULL;



	return ret;

}



DEFINE_SIMPLE_ATTRIBUTE(mhi_sat_debugfs_fops, NULL,

			mhi_sat_trigger_init, "%llu\n");



static int mhi_sat_init(void)

{

	struct mhi_sat_subsys *subsys;
@@ -1066,6 +1110,20 @@ static int mhi_sat_init(void) 
		subsys->ipc_log = ipc_log_context_create(IPC_LOG_PAGES, log, 0);

	}



	/* create debugfs entry if defer_init is enabled */

	if (mhi_sat_defer_init) {

		mhi_sat_driver.dentry = debugfs_create_dir("mhi_sat", NULL);

		if (IS_ERR_OR_NULL(mhi_sat_driver.dentry)) {

			ret = -ENODEV;

			goto error_sat_init;

		}



		debugfs_create_file("debug", 0444, mhi_sat_driver.dentry, NULL,

				    &mhi_sat_debugfs_fops);



		return 0;

	}



	ret = register_rpmsg_driver(&mhi_sat_rpmsg_driver);

	if (ret)

		goto error_sat_init;