Commit 770f75eb authored by zhangyuyang's avatar zhangyuyang
Browse files

drivers:misc:sdma-dae remove lock while pausing channels 

kunpeng inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/


CVE: NA

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

1. remove mutex lock to avoid software lockup problems.

Fixes: f8eeb398 ("drivers: misc: sdma-dae: support channel management")
Signed-off-by: default avatarzhangyuyang <zhangyuyang31@huawei.com>
parent d7de0e51

drivers/misc/sdma-dae/sdma_cdev.c

+24 −35
Original line number Diff line number Diff line
@@ -248,57 +248,49 @@ static bool sdma_wait_cq_writeback(struct hisi_sdma_channel *pchannel) 
	return (cnt <= SDMA_POLL_TIMEOUT);

}



static void sdma_pause_channel(struct hisi_sdma_device *psdma_dev)

static void sdma_pause_single_channel(struct hisi_sdma_channel *pchannel,

				      struct hisi_sdma_device *psdma_dev)

{

	struct hisi_sdma_channel *pchannel;

	bool flag;

	int i;

	u16 idx = pchannel->idx;



	for (i = 0; i < HISI_SDMA_DEFAULT_CHANNEL_NUM; i++) {

		pchannel = psdma_dev->channels + i;

		if (sdma_wait_hardware_done(pchannel) == false) {

			pr_warn("SDMA %u chn %d hardware not finish all sqes!\n",

				psdma_dev->idx, i);

			continue;

		}

	if (sdma_wait_hardware_done(pchannel) == false)

		pr_warn("SDMA %u chn %hu hardware not finish all sqes!\n",

			psdma_dev->idx, idx);



	sdma_channel_set_pause(pchannel);

		flag = sdma_wait_cq_writeback(pchannel);

		if (flag)

	if (sdma_wait_cq_writeback(pchannel))

		sdma_channel_reset_sq_cq(pchannel);

	else

			pr_warn("SDMA %u chn %d hardware not write back all cqes!\n",

				psdma_dev->idx, i);

	}

		pr_warn("SDMA %u chn %hu hardware not write back all cqes!\n",

			psdma_dev->idx, idx);



	return;

}



static void sdma_wait_channel_quiescent(struct hisi_sdma_device *psdma_dev)

static void sdma_pause_channels(struct hisi_sdma_device *psdma_dev)

{

	struct hisi_sdma_channel *pchannel;

	bool flag;

	int i;



	for (i = 0; i < HISI_SDMA_DEFAULT_CHANNEL_NUM; i++) {

		pchannel = psdma_dev->channels + i;

		if (sdma_channel_is_quiescent(pchannel))

			continue;

		sdma_pause_single_channel(pchannel, psdma_dev);

	}



		if (sdma_channel_is_paused(pchannel)) {

			sdma_channel_reset_sq_cq(pchannel);

			continue;

	return;

}



		if (sdma_wait_hardware_done(pchannel) == false) {

			pr_warn("SDMA %u chn %d hardware not finish all sqes!\n",

				psdma_dev->idx, i);

static void sdma_wait_channel_quiescent(struct hisi_sdma_device *psdma_dev)

{

	struct hisi_sdma_channel *pchannel;

	int i;



	for (i = 0; i < HISI_SDMA_DEFAULT_CHANNEL_NUM; i++) {

		pchannel = psdma_dev->channels + i;

		if (sdma_channel_is_quiescent(pchannel))

			continue;

		}



		sdma_channel_set_pause(pchannel);

		flag = sdma_wait_cq_writeback(pchannel);

		if (flag)

		if (sdma_wait_cq_writeback(pchannel))

			sdma_channel_reset_sq_cq(pchannel);

		else

			pr_warn("SDMA %u chn %d hardware not write back all cqes!\n",
@@ -338,13 +330,12 @@ static void sdma_mmu_release_pause(struct mmu_notifier *mn, struct mm_struct *mm 
	if (!sdma_mn->data)

		return;



	mutex_lock(g_info.mutex_lock);

	if (atomic_read(&exit_processes) == 0) {

		atomic_set(&exit_processes, 1);

		pr_warn("SDMA exit exceptionally, stop SDMA tasks before mm exit.\n");

		for (i = 0; i < g_info.core_dev->sdma_device_num; i++) {

			psdma_dev = g_info.core_dev->sdma_devices[i];

			sdma_pause_channel(psdma_dev);

			sdma_pause_channels(psdma_dev);

		}

	} else {

		for (i = 0; i < g_info.core_dev->sdma_device_num; i++) {
@@ -352,7 +343,6 @@ static void sdma_mmu_release_pause(struct mmu_notifier *mn, struct mm_struct *mm 
			sdma_wait_channel_quiescent(psdma_dev);

		}

	}

	mutex_unlock(g_info.mutex_lock);



	return;

}
@@ -578,9 +568,8 @@ static int __do_sdma_open(struct hisi_sdma_device *psdma_dev, struct file *file) 
	}



	ret = sdma_pause_mmu_handler(current->mm, data);

	if (ret != 0) {

	if (ret != 0)

		goto sva_unbind;

	}



	atomic_add(1, &ttl_processes);