Commit fec7fa0a authored by Sebastian Andrzej Siewior's avatar Sebastian Andrzej Siewior Committed by Jakub Kicinski
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chelsio: cxgb: Replace the workqueue with threaded interrupt 



The external interrupt (F_PL_INTR_EXT) needs to be handled in a process
context and this is accomplished by utilizing a workqueue.

The process context can also be provided by a threaded interrupt instead
of a workqueue. The threaded interrupt can be used later for other
interrupt related processing which require non-atomic context without
using yet another workqueue. free_irq() also ensures that the thread is
done which is currently missing (the worker could continue after the
module has been removed).

Save pending flags in pending_thread_intr. Use the same mechanism
to disable F_PL_INTR_EXT as interrupt source like it is used before the
worker is scheduled. Enable the interrupt again once
t1_elmer0_ext_intr_handler() is done.

Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 462e99a1

drivers/net/ethernet/chelsio/cxgb/common.h

+2 −3
Original line number Diff line number Diff line
@@ -238,7 +238,6 @@ struct adapter { 
	int msg_enable;

	u32 mmio_len;



	struct work_struct ext_intr_handler_task;

	struct adapter_params params;



	/* Terminator modules. */
@@ -257,6 +256,7 @@ struct adapter { 


	/* guards async operations */

	spinlock_t async_lock ____cacheline_aligned;

	u32 pending_thread_intr;

	u32 slow_intr_mask;

	int t1powersave;

};
@@ -334,8 +334,7 @@ void t1_interrupts_enable(adapter_t *adapter); 
void t1_interrupts_disable(adapter_t *adapter);

void t1_interrupts_clear(adapter_t *adapter);

int t1_elmer0_ext_intr_handler(adapter_t *adapter);

void t1_elmer0_ext_intr(adapter_t *adapter);

int t1_slow_intr_handler(adapter_t *adapter);

irqreturn_t t1_slow_intr_handler(adapter_t *adapter);



int t1_link_start(struct cphy *phy, struct cmac *mac, struct link_config *lc);

const struct board_info *t1_get_board_info(unsigned int board_id);

drivers/net/ethernet/chelsio/cxgb/cxgb2.c

+4 −40
Original line number Diff line number Diff line
@@ -211,7 +211,8 @@ static int cxgb_up(struct adapter *adapter) 
	t1_interrupts_clear(adapter);



	adapter->params.has_msi = !disable_msi && !pci_enable_msi(adapter->pdev);

	err = request_irq(adapter->pdev->irq, t1_interrupt,

	err = request_threaded_irq(adapter->pdev->irq, t1_interrupt,

				   t1_interrupt_thread,

				   adapter->params.has_msi ? 0 : IRQF_SHARED,

				   adapter->name, adapter);

	if (err) {
@@ -916,41 +917,6 @@ static void mac_stats_task(struct work_struct *work) 
	spin_unlock(&adapter->work_lock);

}



/*

 * Processes elmer0 external interrupts in process context.

 */

static void ext_intr_task(struct work_struct *work)

{

	struct adapter *adapter =

		container_of(work, struct adapter, ext_intr_handler_task);



	t1_elmer0_ext_intr_handler(adapter);



	/* Now reenable external interrupts */

	spin_lock_irq(&adapter->async_lock);

	adapter->slow_intr_mask |= F_PL_INTR_EXT;

	writel(F_PL_INTR_EXT, adapter->regs + A_PL_CAUSE);

	writel(adapter->slow_intr_mask | F_PL_INTR_SGE_DATA,

		   adapter->regs + A_PL_ENABLE);

	spin_unlock_irq(&adapter->async_lock);

}



/*

 * Interrupt-context handler for elmer0 external interrupts.

 */

void t1_elmer0_ext_intr(struct adapter *adapter)

{

	/*

	 * Schedule a task to handle external interrupts as we require

	 * a process context.  We disable EXT interrupts in the interim

	 * and let the task reenable them when it's done.

	 */

	adapter->slow_intr_mask &= ~F_PL_INTR_EXT;

	writel(adapter->slow_intr_mask | F_PL_INTR_SGE_DATA,

		   adapter->regs + A_PL_ENABLE);

	schedule_work(&adapter->ext_intr_handler_task);

}



void t1_fatal_err(struct adapter *adapter)

{

	if (adapter->flags & FULL_INIT_DONE) {
@@ -1062,8 +1028,6 @@ static int init_one(struct pci_dev *pdev, const struct pci_device_id *ent) 
			spin_lock_init(&adapter->async_lock);

			spin_lock_init(&adapter->mac_lock);



			INIT_WORK(&adapter->ext_intr_handler_task,

				  ext_intr_task);

			INIT_DELAYED_WORK(&adapter->stats_update_task,

					  mac_stats_task);

drivers/net/ethernet/chelsio/cxgb/sge.c

+30 −3
Original line number Diff line number Diff line
@@ -1619,11 +1619,38 @@ int t1_poll(struct napi_struct *napi, int budget) 
	return work_done;

}



irqreturn_t t1_interrupt_thread(int irq, void *data)

{

	struct adapter *adapter = data;

	u32 pending_thread_intr;



	spin_lock_irq(&adapter->async_lock);

	pending_thread_intr = adapter->pending_thread_intr;

	adapter->pending_thread_intr = 0;

	spin_unlock_irq(&adapter->async_lock);



	if (!pending_thread_intr)

		return IRQ_NONE;



	if (pending_thread_intr & F_PL_INTR_EXT)

		t1_elmer0_ext_intr_handler(adapter);



	spin_lock_irq(&adapter->async_lock);

	adapter->slow_intr_mask |= F_PL_INTR_EXT;



	writel(F_PL_INTR_EXT, adapter->regs + A_PL_CAUSE);

	writel(adapter->slow_intr_mask | F_PL_INTR_SGE_DATA,

	       adapter->regs + A_PL_ENABLE);

	spin_unlock_irq(&adapter->async_lock);



	return IRQ_HANDLED;

}



irqreturn_t t1_interrupt(int irq, void *data)

{

	struct adapter *adapter = data;

	struct sge *sge = adapter->sge;

	int handled;

	irqreturn_t handled;



	if (likely(responses_pending(adapter))) {

		writel(F_PL_INTR_SGE_DATA, adapter->regs + A_PL_CAUSE);
@@ -1645,10 +1672,10 @@ irqreturn_t t1_interrupt(int irq, void *data) 
	handled = t1_slow_intr_handler(adapter);

	spin_unlock(&adapter->async_lock);



	if (!handled)

	if (handled == IRQ_NONE)

		sge->stats.unhandled_irqs++;



	return IRQ_RETVAL(handled != 0);

	return handled;

}



/*

drivers/net/ethernet/chelsio/cxgb/sge.h

+1 −0
Original line number Diff line number Diff line
@@ -74,6 +74,7 @@ struct sge *t1_sge_create(struct adapter *, struct sge_params *); 
int t1_sge_configure(struct sge *, struct sge_params *);

int t1_sge_set_coalesce_params(struct sge *, struct sge_params *);

void t1_sge_destroy(struct sge *);

irqreturn_t t1_interrupt_thread(int irq, void *data);

irqreturn_t t1_interrupt(int irq, void *cookie);

int t1_poll(struct napi_struct *, int);

drivers/net/ethernet/chelsio/cxgb/subr.c

+18 −8
Original line number Diff line number Diff line
@@ -210,7 +210,7 @@ static int fpga_phy_intr_handler(adapter_t *adapter) 
/*

 * Slow path interrupt handler for FPGAs.

 */

static int fpga_slow_intr(adapter_t *adapter)

static irqreturn_t fpga_slow_intr(adapter_t *adapter)

{

	u32 cause = readl(adapter->regs + A_PL_CAUSE);
@@ -238,7 +238,7 @@ static int fpga_slow_intr(adapter_t *adapter) 
	if (cause)

		writel(cause, adapter->regs + A_PL_CAUSE);



	return cause != 0;

	return cause == 0 ? IRQ_NONE : IRQ_HANDLED;

}

#endif
@@ -842,13 +842,14 @@ void t1_interrupts_clear(adapter_t* adapter) 
/*

 * Slow path interrupt handler for ASICs.

 */

static int asic_slow_intr(adapter_t *adapter)

static irqreturn_t asic_slow_intr(adapter_t *adapter)

{

	u32 cause = readl(adapter->regs + A_PL_CAUSE);

	irqreturn_t ret = IRQ_HANDLED;



	cause &= adapter->slow_intr_mask;

	if (!cause)

		return 0;

		return IRQ_NONE;

	if (cause & F_PL_INTR_SGE_ERR)

		t1_sge_intr_error_handler(adapter->sge);

	if (cause & F_PL_INTR_TP)
@@ -857,16 +858,25 @@ static int asic_slow_intr(adapter_t *adapter) 
		t1_espi_intr_handler(adapter->espi);

	if (cause & F_PL_INTR_PCIX)

		t1_pci_intr_handler(adapter);

	if (cause & F_PL_INTR_EXT)

		t1_elmer0_ext_intr(adapter);

	if (cause & F_PL_INTR_EXT) {

		/* Wake the threaded interrupt to handle external interrupts as

		 * we require a process context. We disable EXT interrupts in

		 * the interim and let the thread reenable them when it's done.

		 */

		adapter->pending_thread_intr |= F_PL_INTR_EXT;

		adapter->slow_intr_mask &= ~F_PL_INTR_EXT;

		writel(adapter->slow_intr_mask | F_PL_INTR_SGE_DATA,

		       adapter->regs + A_PL_ENABLE);

		ret = IRQ_WAKE_THREAD;

	}



	/* Clear the interrupts just processed. */

	writel(cause, adapter->regs + A_PL_CAUSE);

	readl(adapter->regs + A_PL_CAUSE); /* flush writes */

	return 1;

	return ret;

}



int t1_slow_intr_handler(adapter_t *adapter)

irqreturn_t t1_slow_intr_handler(adapter_t *adapter)

{

#ifdef CONFIG_CHELSIO_T1_1G

	if (!t1_is_asic(adapter))