Commit 65b5b0e1 authored by Mikhail Karpenko's avatar Mikhail Karpenko
Browse files

Update locking for queue pointers

parent 0564ebaf

src/drivers/ata/ahci_elphel.c

+23 −9
Original line number Original line Diff line number Diff line
@@ -1185,22 +1185,31 @@ static void finish_rec(struct elphel_ahci_priv *dpriv) 
/** Move a pointer to free command slot one step forward. This function holds spin lock #elphel_ahci_priv::flags_lock */

/** Move a pointer to free command slot one step forward. This function holds spin lock #elphel_ahci_priv::flags_lock */

static int move_tail(struct elphel_ahci_priv *dpriv)

static int move_tail(struct elphel_ahci_priv *dpriv)

{

{

	int ret;

	unsigned long irq_flags;

	size_t slot = (dpriv->tail_ptr + 1) % MAX_CMD_SLOTS;

	size_t slot = (dpriv->tail_ptr + 1) % MAX_CMD_SLOTS;





	spin_lock_irqsave(&dpriv->flags_lock, irq_flags);

	if (slot != dpriv->head_ptr) {

	if (slot != dpriv->head_ptr) {

		set_flag(dpriv, LOCK_TAIL);

		dpriv->flags |= LOCK_TAIL;

		dpriv->tail_ptr = slot;

		dpriv->tail_ptr = slot;

		dev_dbg(dpriv->dev, "move tail pointer to slot: %u\n", slot);

		ret = 0;

		return 0;

	} else {

	} else {

		/* no more free command slots */

		/* no more free command slots */

		return -1;

		ret = -1;

	}

	}

	spin_unlock_irqrestore(&dpriv->flags_lock, irq_flags);



	if (ret == 0)

		dev_dbg(dpriv->dev, "move tail pointer to slot: %u\n", slot);



	return ret;

}

}





/** Move a pointer to next ready command. This function holds spin lock #elphel_ahci_priv::flags_lock*/

/** Move a pointer to next ready command. This function holds spin lock #elphel_ahci_priv::flags_lock*/

static int move_head(struct elphel_ahci_priv *dpriv)

static int move_head(struct elphel_ahci_priv *dpriv)

{

{

	int ret;

	size_t use_tail;

	size_t use_tail;

	unsigned long irq_flags;

	unsigned long irq_flags;

	size_t slot = (dpriv->head_ptr + 1) % MAX_CMD_SLOTS;

	size_t slot = (dpriv->head_ptr + 1) % MAX_CMD_SLOTS;
@@ -1212,17 +1221,19 @@ static int move_head(struct elphel_ahci_priv *dpriv) 
	} else {

	} else {

		use_tail = dpriv->tail_ptr;

		use_tail = dpriv->tail_ptr;

	}

	}

	spin_unlock_irqrestore(&dpriv->flags_lock, irq_flags);



	if (dpriv->head_ptr != use_tail) {

	if (dpriv->head_ptr != use_tail) {

		dpriv->head_ptr = slot;

		dpriv->head_ptr = slot;

		dev_dbg(dpriv->dev, "move head pointer to slot: %u\n", slot);

		ret = 0;

		return 0;

	} else {

	} else {

		/* no more commands in queue */

		/* no more commands in queue */

		return -1;

		ret = -1;

	}

	}

	spin_unlock_irqrestore(&dpriv->flags_lock, irq_flags);



	if (ret == 0)

		dev_dbg(dpriv->dev, "move head pointer to slot: %u\n", slot);





	return ret;

}

}





/** Check if command queue is empty */

/** Check if command queue is empty */
@@ -1382,6 +1393,7 @@ static ssize_t rawdev_write(struct device *dev, ///< device structure associate 
		} else {

		} else {

			dpriv->flags |= DELAYED_FINISH;

			dpriv->flags |= DELAYED_FINISH;

		}

		}

		dpriv->datascope.reg_stat[CMD_RCVD] = dpriv->datascope.reg_stat[CMD_RCVD] + 1;

		return buff_sz;

		return buff_sz;

	}

	}
@@ -1440,6 +1452,8 @@ static ssize_t rawdev_write(struct device *dev, ///< device structure associate 
	/* new command slot is ready now and can be unlocked */

	/* new command slot is ready now and can be unlocked */

	reset_flag(dpriv, LOCK_TAIL);

	reset_flag(dpriv, LOCK_TAIL);





	dpriv->datascope.reg_stat[CMD_RCVD] = dpriv->datascope.reg_stat[CMD_RCVD] + 1;



	if (!proceed) {

	if (!proceed) {

		/* disk may be free by the moment, try to grab it */

		/* disk may be free by the moment, try to grab it */

		spin_lock_irqsave(&dpriv->flags_lock, irq_flags);

		spin_lock_irqsave(&dpriv->flags_lock, irq_flags);

src/drivers/ata/ahci_elphel.h

+2 −1
Original line number Original line Diff line number Diff line
@@ -83,7 +83,8 @@ enum { 
	REG_PxSERR,                                  ///< value of PxSERR in data buffer

	REG_PxSERR,                                  ///< value of PxSERR in data buffer

	IRQ_COUNTER,                                 ///< interrupts counter for internal commands

	IRQ_COUNTER,                                 ///< interrupts counter for internal commands

	IRQ_COUNTER_SYS,                             ///< interrupts counter for system commands

	IRQ_COUNTER_SYS,                             ///< interrupts counter for system commands

	CMD_SENT                                     ///< number of commands sent

	CMD_SENT,                                    ///< number of commands sent

	CMD_RCVD                                     ///< number of commands received

};

};

struct datascope {

struct datascope {

    void __iomem *timestamp_reg;                 ///< register in vendor specific address range (PxVS) where timestamp can be written

    void __iomem *timestamp_reg;                 ///< register in vendor specific address range (PxVS) where timestamp can be written