Set spin locks for LOCK_TAIL flag (c9b13370) · Commits · Elphel / linux-elphel

src/drivers/ata/ahci_elphel.c

+40 −16

Original line number	Original line	Diff line number	Diff line
	@@ -34,7 +34,6 @@
	#include "ahci_elphel.h"		#include "ahci_elphel.h"
	#include "../elphel/exif393.h"		#include "../elphel/exif393.h"
	#include "../elphel/jpeghead.h"		#include "../elphel/jpeghead.h"
	#include "../elphel/x393_helpers.h"

	#define DRV_NAME "elphel-ahci"		#define DRV_NAME "elphel-ahci"
	/*		/*
	@@ -68,11 +67,13 @@ static int process_cmd(struct elphel_ahci_priv *dpriv);
	static inline size_t get_size_from(const struct fvec *vects, int index, size_t offset, int all);		static inline size_t get_size_from(const struct fvec *vects, int index, size_t offset, int all);
	static inline void vectmov(struct fvec *vec, size_t len);		static inline void vectmov(struct fvec *vec, size_t len);
	static inline void vectsplit(struct fvec vect, struct fvec parts, size_t *n_elem);		static inline void vectsplit(struct fvec vect, struct fvec parts, size_t *n_elem);
	int move_tail(struct elphel_ahci_priv *dpriv);		static int move_tail(struct elphel_ahci_priv *dpriv);
	int move_head(struct elphel_ahci_priv *dpriv);		static int move_head(struct elphel_ahci_priv *dpriv);
	size_t get_prev_slot(const struct elphel_ahci_priv *dpriv);		static size_t get_prev_slot(const struct elphel_ahci_priv *dpriv);
	int is_cmdq_empty(const struct elphel_ahci_priv *dpriv);		static int is_cmdq_empty(const struct elphel_ahci_priv *dpriv);
	void process_queue(unsigned long data);		void process_queue(unsigned long data);
			static void set_flag(struct elphel_ahci_priv *drpiv, uint32_t flag);
			static void reset_flag(struct elphel_ahci_priv *dpriv, uint32_t flag);
	/* debug functions */		/* debug functions */
	static int check_chunks(struct fvec *vects);		static int check_chunks(struct fvec *vects);
	static void dump_sg_list(const struct device dev, const struct fvec sgl, size_t elems);		static void dump_sg_list(const struct device dev, const struct fvec sgl, size_t elems);
	@@ -139,7 +140,7 @@ static irqreturn_t elphel_irq_handler(int irq, void * dev_instance)
	dpriv->flags &= ~IRQ_SIMPLE;		dpriv->flags &= ~IRQ_SIMPLE;
	irq_stat = readl(port_mmio + PORT_IRQ_STAT);		irq_stat = readl(port_mmio + PORT_IRQ_STAT);

	dev_dbg(host->dev, "irq_stat = 0x%x, host irq_stat = 0x%x, time stamp: %u\n", irq_stat, host_irq_stat, get_rtc_usec());		dev_dbg(host->dev, "irq_stat = 0x%x, host irq_stat = 0x%x\n", irq_stat, host_irq_stat);

	writel(irq_stat, port_mmio + PORT_IRQ_STAT);		writel(irq_stat, port_mmio + PORT_IRQ_STAT);
	writel(host_irq_stat, hpriv->mmio + HOST_IRQ_STAT);		writel(host_irq_stat, hpriv->mmio + HOST_IRQ_STAT);
	@@ -407,6 +408,26 @@ static void elphel_qc_prep(struct ata_queued_cmd *qc)
	AHCI_CMD_TBL_AR_SZ, DMA_TO_DEVICE);		AHCI_CMD_TBL_AR_SZ, DMA_TO_DEVICE);
	}		}

			/** Set flag @e flag in driver private structure. This function uses spin lock to access the flags variable. */
			static void set_flag(struct elphel_ahci_priv *dpriv, uint32_t flag)
			{
			unsigned long irq_flags;

			spin_lock_irqsave(&dpriv->flags_lock, irq_flags);
			dpriv->flags \|= flag;
			spin_unlock_irqrestore(&dpriv->flags_lock, irq_flags);
			}

			/** Reset flag @e flag in driver private structure. This function uses spin lock to access the flags variable. */
			static void reset_flag(struct elphel_ahci_priv *dpriv, uint32_t flag)
			{
			unsigned long irq_flags;

			spin_lock_irqsave(&dpriv->flags_lock, irq_flags);
			dpriv->flags &= ~flag;
			spin_unlock_irqrestore(&dpriv->flags_lock, irq_flags);
			}

	/** Map buffer vectors to S/G list and return the number of vectors mapped */		/** Map buffer vectors to S/G list and return the number of vectors mapped */
	static int map_vectors(struct elphel_ahci_priv *dpriv)		static int map_vectors(struct elphel_ahci_priv *dpriv)
	{		{
	@@ -976,13 +997,13 @@ static void finish_rec(struct elphel_ahci_priv *dpriv)
	process_cmd(dpriv);		process_cmd(dpriv);
	}		}

	/** Move a pointer to free command slot one step forward */		/** Move a pointer to free command slot one step forward. This function holds spin lock #elphel_ahci_priv::flags_lock */
	int move_tail(struct elphel_ahci_priv *dpriv)		static int move_tail(struct elphel_ahci_priv *dpriv)
	{		{
	size_t slot = (dpriv->tail_ptr + 1) % MAX_CMD_SLOTS;		size_t slot = (dpriv->tail_ptr + 1) % MAX_CMD_SLOTS;

	if (slot != dpriv->head_ptr) {		if (slot != dpriv->head_ptr) {
	dpriv->flags \|= LOCK_TAIL;		set_flag(dpriv, LOCK_TAIL);
	dpriv->tail_ptr = slot;		dpriv->tail_ptr = slot;
	dev_dbg(dpriv->dev, "move tail pointer to slot: %u\n", slot);		dev_dbg(dpriv->dev, "move tail pointer to slot: %u\n", slot);
	return 0;		return 0;
	@@ -992,18 +1013,21 @@ int move_tail(struct elphel_ahci_priv *dpriv)
	}		}
	}		}

	/** Move a pointer to next ready command */		/** Move a pointer to next ready command. This function holds spin lock #elphel_ahci_priv::flags_lock*/
	int move_head(struct elphel_ahci_priv *dpriv)		static int move_head(struct elphel_ahci_priv *dpriv)
	{		{
	size_t use_tail;		size_t use_tail;
			unsigned long irq_flags;
	size_t slot = (dpriv->head_ptr + 1) % MAX_CMD_SLOTS;		size_t slot = (dpriv->head_ptr + 1) % MAX_CMD_SLOTS;

			spin_lock_irqsave(&dpriv->flags_lock, irq_flags);
	if (dpriv->flags & LOCK_TAIL) {		if (dpriv->flags & LOCK_TAIL) {
	/* current command slot is not ready yet, use previous */		/* current command slot is not ready yet, use previous */
	use_tail = get_prev_slot(dpriv);		use_tail = get_prev_slot(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;
	@@ -1017,7 +1041,7 @@ int move_head(struct elphel_ahci_priv *dpriv)
	}		}

	/** Check if command queue is empty */		/** Check if command queue is empty */
	int is_cmdq_empty(const struct elphel_ahci_priv *dpriv)		static int is_cmdq_empty(const struct elphel_ahci_priv *dpriv)
	{		{
	size_t use_tail;		size_t use_tail;

	@@ -1034,7 +1058,7 @@ int is_cmdq_empty(const struct elphel_ahci_priv *dpriv)
	}		}

	/** Get command slot before the last one filled in */		/** Get command slot before the last one filled in */
	size_t get_prev_slot(const struct elphel_ahci_priv *dpriv)		static size_t get_prev_slot(const struct elphel_ahci_priv *dpriv)
	{		{
	size_t slot;		size_t slot;

	@@ -1089,13 +1113,13 @@ static ssize_t rawdev_write(struct device *dev, ///< device structure associate

	if (move_tail(dpriv) == -1) {		if (move_tail(dpriv) == -1) {
	/* we are not ready yet because command queue is full */		/* we are not ready yet because command queue is full */
	printk_ratelimited(KERN_DEBUG "command queue is full\n");		printk_ratelimited(KERN_DEBUG "command queue is full, flags = %u, proceed = %d\n", dpriv->flags, proceed);
	return -EAGAIN;		return -EAGAIN;
	}		}
	chunks = dpriv->data_chunks[dpriv->tail_ptr];		chunks = dpriv->data_chunks[dpriv->tail_ptr];
	buffs = &dpriv->fbuffs[dpriv->tail_ptr];		buffs = &dpriv->fbuffs[dpriv->tail_ptr];

	dev_dbg(dev, "process frame from sensor port: %u, command = %d\n", fdata.sensor_port, fdata.cmd);		dev_dbg(dev, "process frame from sensor port: %u, command = %d, flags = %u\n", fdata.sensor_port, fdata.cmd, dpriv->flags);
	if (fdata.cmd & DRV_CMD_EXIF) {		if (fdata.cmd & DRV_CMD_EXIF) {
	rcvd = exif_get_data(fdata.sensor_port, fdata.meta_index, buffs->exif_buff.iov_base, buffs->exif_buff.iov_len);		rcvd = exif_get_data(fdata.sensor_port, fdata.meta_index, buffs->exif_buff.iov_base, buffs->exif_buff.iov_len);
	chunks[CHUNK_EXIF].iov_len = rcvd;		chunks[CHUNK_EXIF].iov_len = rcvd;
	@@ -1135,7 +1159,7 @@ static ssize_t rawdev_write(struct device *dev, ///< device structure associate
	}		}
	align_frame(dpriv);		align_frame(dpriv);
	/* new command slot is ready now and can be unlocked */		/* new command slot is ready now and can be unlocked */
	dpriv->flags &= ~LOCK_TAIL;		reset_flag(dpriv, LOCK_TAIL);

	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 */

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