Commit c9834d84 authored by Allen Pais's avatar Allen Pais Committed by Jassi Brar
Browse files

mailbox: Convert from tasklet to BH workqueue 

The only generic interface to execute asynchronously in the BH context is
tasklet; however, it's marked deprecated and has some design flaws. To
replace tasklets, BH workqueue support was recently added. A BH workqueue
behaves similarly to regular workqueues except that the queued work items
are executed in the BH context.

Based on the work done by Tejun Heo <tj@kernel.org>
Branch: https://git.kernel.org/pub/scm/linux/kernel/git/tj/wq.git

 for-6.10

Signed-off-by: default avatarAllen Pais <allen.lkml@gmail.com>
Signed-off-by: default avatarJassi Brar <jassisinghbrar@gmail.com>
parent 747a69a1

drivers/mailbox/bcm-pdc-mailbox.c

+11 −10
Original line number Diff line number Diff line
@@ -43,6 +43,7 @@ 
#include <linux/dma-direction.h>

#include <linux/dma-mapping.h>

#include <linux/dmapool.h>

#include <linux/workqueue.h>



#define PDC_SUCCESS  0
@@ -293,8 +294,8 @@ struct pdc_state { 


	unsigned int pdc_irq;



	/* tasklet for deferred processing after DMA rx interrupt */

	struct tasklet_struct rx_tasklet;

	/* work for deferred processing after DMA rx interrupt */

	struct work_struct rx_work;



	/* Number of bytes of receive status prior to each rx frame */

	u32 rx_status_len;
@@ -952,18 +953,18 @@ static irqreturn_t pdc_irq_handler(int irq, void *data) 
	iowrite32(intstatus, pdcs->pdc_reg_vbase + PDC_INTSTATUS_OFFSET);



	/* Wakeup IRQ thread */

	tasklet_schedule(&pdcs->rx_tasklet);

	queue_work(system_bh_wq, &pdcs->rx_work);

	return IRQ_HANDLED;

}



/**

 * pdc_tasklet_cb() - Tasklet callback that runs the deferred processing after

 * pdc_work_cb() - Work callback that runs the deferred processing after

 * a DMA receive interrupt. Reenables the receive interrupt.

 * @t: Pointer to the Altera sSGDMA channel structure

 */

static void pdc_tasklet_cb(struct tasklet_struct *t)

static void pdc_work_cb(struct work_struct *t)

{

	struct pdc_state *pdcs = from_tasklet(pdcs, t, rx_tasklet);

	struct pdc_state *pdcs = from_work(pdcs, t, rx_work);



	pdc_receive(pdcs);
@@ -1577,8 +1578,8 @@ static int pdc_probe(struct platform_device *pdev) 


	pdc_hw_init(pdcs);



	/* Init tasklet for deferred DMA rx processing */

	tasklet_setup(&pdcs->rx_tasklet, pdc_tasklet_cb);

	/* Init work for deferred DMA rx processing */

	INIT_WORK(&pdcs->rx_work, pdc_work_cb);



	err = pdc_interrupts_init(pdcs);

	if (err)
@@ -1595,7 +1596,7 @@ static int pdc_probe(struct platform_device *pdev) 
	return PDC_SUCCESS;



cleanup_buf_pool:

	tasklet_kill(&pdcs->rx_tasklet);

	cancel_work_sync(&pdcs->rx_work);

	dma_pool_destroy(pdcs->rx_buf_pool);



cleanup_ring_pool:
@@ -1611,7 +1612,7 @@ static void pdc_remove(struct platform_device *pdev) 


	pdc_free_debugfs();



	tasklet_kill(&pdcs->rx_tasklet);

	cancel_work_sync(&pdcs->rx_work);



	pdc_hw_disable(pdcs);

drivers/mailbox/imx-mailbox.c

+8 −8
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ 
#include <linux/pm_runtime.h>

#include <linux/suspend.h>

#include <linux/slab.h>

#include <linux/workqueue.h>



#include "mailbox.h"
@@ -80,7 +81,7 @@ struct imx_mu_con_priv { 
	char			irq_desc[IMX_MU_CHAN_NAME_SIZE];

	enum imx_mu_chan_type	type;

	struct mbox_chan	*chan;

	struct tasklet_struct	txdb_tasklet;

	struct work_struct 	txdb_work;

};



struct imx_mu_priv {
@@ -232,7 +233,7 @@ static int imx_mu_generic_tx(struct imx_mu_priv *priv, 
		break;

	case IMX_MU_TYPE_TXDB:

		imx_mu_xcr_rmw(priv, IMX_MU_GCR, IMX_MU_xCR_GIRn(priv->dcfg->type, cp->idx), 0);

		tasklet_schedule(&cp->txdb_tasklet);

		queue_work(system_bh_wq, &cp->txdb_work);

		break;

	case IMX_MU_TYPE_TXDB_V2:

		imx_mu_xcr_rmw(priv, IMX_MU_GCR, IMX_MU_xCR_GIRn(priv->dcfg->type, cp->idx), 0);
@@ -420,7 +421,7 @@ static int imx_mu_seco_tx(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp, 
		}



		/* Simulate hack for mbox framework */

		tasklet_schedule(&cp->txdb_tasklet);

		queue_work(system_bh_wq, &cp->txdb_work);



		break;

	default:
@@ -484,9 +485,9 @@ static int imx_mu_seco_rxdb(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp 
	return err;

}



static void imx_mu_txdb_tasklet(unsigned long data)

static void imx_mu_txdb_work(struct work_struct *t)

{

	struct imx_mu_con_priv *cp = (struct imx_mu_con_priv *)data;

	struct imx_mu_con_priv *cp = from_work(cp, t, txdb_work);



	mbox_chan_txdone(cp->chan, 0);

}
@@ -570,8 +571,7 @@ static int imx_mu_startup(struct mbox_chan *chan) 


	if (cp->type == IMX_MU_TYPE_TXDB) {

		/* Tx doorbell don't have ACK support */

		tasklet_init(&cp->txdb_tasklet, imx_mu_txdb_tasklet,

			     (unsigned long)cp);

		INIT_WORK(&cp->txdb_work, imx_mu_txdb_work);

		return 0;

	}
@@ -615,7 +615,7 @@ static void imx_mu_shutdown(struct mbox_chan *chan) 
	}



	if (cp->type == IMX_MU_TYPE_TXDB) {

		tasklet_kill(&cp->txdb_tasklet);

		cancel_work_sync(&cp->txdb_work);

		pm_runtime_put_sync(priv->dev);

		return;

	}