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Commit ac825992 authored by Lloyd Atkinson's avatar Lloyd Atkinson
Browse files

drm/msm: protect register dumps and debugfs with mutex 



Add a mutex to serialize sde debug register dumps for
back-to-back dumps, as well as any debugfs access.

Change-Id: I7f6186575df021ce48e18ea980f9c2108b756283
Signed-off-by: default avatarLloyd Atkinson <latkinso@codeaurora.org>
parent 5b93813a

drivers/gpu/drm/msm/sde_dbg.c

+42 −7
Original line number Diff line number Diff line
@@ -168,6 +168,7 @@ struct sde_dbg_vbif_debug_bus { 
 * @evtlog: event log instance

 * @reg_base_list: list of register dumping regions

 * @dev: device pointer

 * @mutex: mutex to serialize access to serialze dumps, debugfs access

 * @power_ctrl: callback structure for enabling power for reading hw registers

 * @req_dump_blks: list of blocks requested for dumping

 * @panic_on_err: whether to kernel panic after triggering dump via debugfs
@@ -183,6 +184,7 @@ static struct sde_dbg_base { 
	struct sde_dbg_evtlog *evtlog;

	struct list_head reg_base_list;

	struct device *dev;

	struct mutex mutex;

	struct sde_dbg_power_ctrl power_ctrl;



	struct sde_dbg_reg_base *req_dump_blks[SDE_DBG_BASE_MAX];
@@ -2554,6 +2556,8 @@ static void _sde_dump_array(struct sde_dbg_reg_base *blk_arr[], 
{

	int i;



	mutex_lock(&sde_dbg_base.mutex);



	sde_evtlog_dump_all(sde_dbg_base.evtlog);



	if (dump_all || !blk_arr || !len) {
@@ -2577,6 +2581,8 @@ static void _sde_dump_array(struct sde_dbg_reg_base *blk_arr[], 


	if (do_panic && sde_dbg_base.panic_on_err)

		panic(name);



	mutex_unlock(&sde_dbg_base.mutex);

}



/**
@@ -2814,11 +2820,14 @@ static int sde_dbg_reg_base_release(struct inode *inode, struct file *file) 
{

	struct sde_dbg_reg_base *dbg = file->private_data;



	mutex_lock(&sde_dbg_base.mutex);

	if (dbg && dbg->buf) {

		kfree(dbg->buf);

		dbg->buf_len = 0;

		dbg->buf = NULL;

	}

	mutex_unlock(&sde_dbg_base.mutex);



	return 0;

}
@@ -2861,8 +2870,10 @@ static ssize_t sde_dbg_reg_base_offset_write(struct file *file, 
	if (cnt > (dbg->max_offset - off))

		cnt = dbg->max_offset - off;



	mutex_lock(&sde_dbg_base.mutex);

	dbg->off = off;

	dbg->cnt = cnt;

	mutex_unlock(&sde_dbg_base.mutex);



	pr_debug("offset=%x cnt=%x\n", off, cnt);
@@ -2889,17 +2900,25 @@ static ssize_t sde_dbg_reg_base_offset_read(struct file *file, 
	if (*ppos)

		return 0;	/* the end */



	if (dbg->off % sizeof(u32))

	mutex_lock(&sde_dbg_base.mutex);

	if (dbg->off % sizeof(u32)) {

		mutex_unlock(&sde_dbg_base.mutex);

		return -EFAULT;

	}



	len = snprintf(buf, sizeof(buf), "0x%08zx %zx\n", dbg->off, dbg->cnt);

	if (len < 0 || len >= sizeof(buf))

	if (len < 0 || len >= sizeof(buf)) {

		mutex_unlock(&sde_dbg_base.mutex);

		return 0;

	}



	if ((count < sizeof(buf)) || copy_to_user(buff, buf, len))

	if ((count < sizeof(buf)) || copy_to_user(buff, buf, len)) {

		mutex_unlock(&sde_dbg_base.mutex);

		return -EFAULT;

	}



	*ppos += len;	/* increase offset */

	mutex_unlock(&sde_dbg_base.mutex);



	return len;

}
@@ -2938,8 +2957,11 @@ static ssize_t sde_dbg_reg_base_reg_write(struct file *file, 
	if (off % sizeof(u32))

		return -EFAULT;



	if (off >= dbg->max_offset)

	mutex_lock(&sde_dbg_base.mutex);

	if (off >= dbg->max_offset) {

		mutex_unlock(&sde_dbg_base.mutex);

		return -EFAULT;

	}



	_sde_dbg_enable_power(true);
@@ -2947,6 +2969,8 @@ static ssize_t sde_dbg_reg_base_reg_write(struct file *file, 


	_sde_dbg_enable_power(false);



	mutex_unlock(&sde_dbg_base.mutex);



	pr_debug("addr=%zx data=%x\n", off, data);



	return count;
@@ -2970,6 +2994,7 @@ static ssize_t sde_dbg_reg_base_reg_read(struct file *file, 
		return -ENODEV;

	}



	mutex_lock(&sde_dbg_base.mutex);

	if (!dbg->buf) {

		char dump_buf[64];

		char *ptr;
@@ -2979,11 +3004,15 @@ static ssize_t sde_dbg_reg_base_reg_read(struct file *file, 
			DIV_ROUND_UP(dbg->cnt, ROW_BYTES);

		dbg->buf = kzalloc(dbg->buf_len, GFP_KERNEL);



		if (!dbg->buf)

		if (!dbg->buf) {

			mutex_unlock(&sde_dbg_base.mutex);

			return -ENOMEM;

		}



		if (dbg->off % sizeof(u32))

		if (dbg->off % sizeof(u32)) {

			mutex_unlock(&sde_dbg_base.mutex);

			return -EFAULT;

		}



		ptr = dbg->base + dbg->off;

		tot = 0;
@@ -3011,16 +3040,20 @@ static ssize_t sde_dbg_reg_base_reg_read(struct file *file, 
		dbg->buf_len = tot;

	}



	if (*ppos >= dbg->buf_len)

	if (*ppos >= dbg->buf_len) {

		mutex_unlock(&sde_dbg_base.mutex);

		return 0; /* done reading */

	}



	len = min(count, dbg->buf_len - (size_t) *ppos);

	if (copy_to_user(user_buf, dbg->buf + *ppos, len)) {

		mutex_unlock(&sde_dbg_base.mutex);

		pr_err("failed to copy to user\n");

		return -EFAULT;

	}



	*ppos += len; /* increase offset */

	mutex_unlock(&sde_dbg_base.mutex);



	return len;

}
@@ -3134,6 +3167,7 @@ int sde_dbg_init(struct device *dev, struct sde_dbg_power_ctrl *power_ctrl) 
		return -EINVAL;

	}



	mutex_init(&sde_dbg_base.mutex);

	INIT_LIST_HEAD(&sde_dbg_base.reg_base_list);

	sde_dbg_base.dev = dev;

	sde_dbg_base.power_ctrl = *power_ctrl;
@@ -3186,6 +3220,7 @@ void sde_dbg_destroy(void) 
	sde_evtlog_destroy(sde_dbg_base.evtlog);

	sde_dbg_base.evtlog = NULL;

	sde_dbg_reg_base_destroy();

	mutex_destroy(&sde_dbg_base.mutex);

}



int sde_dbg_reg_register_base(const char *name, void __iomem *base,