Commit 0ca4da24 authored by Srinivas Pandruvada's avatar Srinivas Pandruvada Committed by Jia, Yingbao
Browse files

platform/x86: ISST: Simplify isst_misc_reg() and isst_misc_unreg() 

mainline inclusion
from mainline-v6.11
commit 440814caedb0e33c56f0478d7fa5b54479013904
category: bugfix
bugzilla: https://gitee.com/openeuler/intel-kernel/issues/IB6QD3
CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=440814caedb0e33c56f0478d7fa5b54479013904



-------------------------------------------------

Intel-SIG: commit 440814caedb0 platform/x86: ISST: Simplify isst_misc_reg() and isst_misc_unreg().
Backport Intel speed select ISST driver bugfix from upstream 6.11.

After commit '1630dc626c87 ("platform/x86: ISST: Add model specific
loading for common module")' isst_misc_reg() and isst_misc_unreg() can be
simplified. Since these functions are only called during module_init()
and module_exit() respectively, there is no contention while calling
misc_register()/misc_deregister or isst_if_cpu_info_init()/
isst_if_cpu_info_exit().

Hence remove mutex and reference counting.

Signed-off-by: default avatarSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Reviewed-by: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20240731184256.1852840-1-srinivas.pandruvada@linux.intel.com


Reviewed-by: default avatarHans de Goede <hdegoede@redhat.com>
Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
[ yingbao jia: amend commit log ]
Signed-off-by: default avataryingbao jia <yingbao.jia@intel.com>
parent 3771612b

drivers/platform/x86/intel_speed_select_if/isst_if_common.c

+11 −31
Original line number Diff line number Diff line
@@ -653,10 +653,6 @@ static long isst_if_def_ioctl(struct file *file, unsigned int cmd, 


/* Lock to prevent module registration when already opened by user space */

static DEFINE_MUTEX(punit_misc_dev_open_lock);

/* Lock to allow one share misc device for all ISST interace */

static DEFINE_MUTEX(punit_misc_dev_reg_lock);

static int misc_usage_count;

static int misc_device_ret;

static int misc_device_open;



static int isst_if_open(struct inode *inode, struct file *file)
@@ -722,40 +718,24 @@ static struct miscdevice isst_if_char_driver = { 


static int isst_misc_reg(void)

{

	mutex_lock(&punit_misc_dev_reg_lock);

	if (misc_device_ret)

		goto unlock_exit;

	int ret;



	if (!misc_usage_count) {

		misc_device_ret = isst_if_cpu_info_init();

		if (misc_device_ret)

			goto unlock_exit;

	ret = isst_if_cpu_info_init();

	if (ret)

		return ret;



		misc_device_ret = misc_register(&isst_if_char_driver);

		if (misc_device_ret) {

	ret = misc_register(&isst_if_char_driver);

	if (ret)

		isst_if_cpu_info_exit();

			goto unlock_exit;

		}

	}

	misc_usage_count++;



unlock_exit:

	mutex_unlock(&punit_misc_dev_reg_lock);



	return misc_device_ret;

	return ret;

}



static void isst_misc_unreg(void)

{

	mutex_lock(&punit_misc_dev_reg_lock);

	if (misc_usage_count)

		misc_usage_count--;

	if (!misc_usage_count && !misc_device_ret) {

	misc_deregister(&isst_if_char_driver);

	isst_if_cpu_info_exit();

}

	mutex_unlock(&punit_misc_dev_reg_lock);

}



/**

 * isst_if_cdev_register() - Register callback for IOCTL