net: macb: Convert tasklet API to new bottom half workqueue mechanism

Migrate tasklet APIs to the new bottom half workqueue mechanism. It
replaces all occurrences of tasklet usage with the appropriate workqueue
APIs throughout the macb driver. This transition ensures compatibility
with the latest design and enhances performance.

Signed-off-by: Allen Pais <allen.lkml@gmail.com>
Link: https://patch.msgid.link/20240730183403.4176544-5-allen.lkml@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/cadence/macb.h

@@ -13,6 +13,7 @@
 #include <linux/net_tstamp.h>
 #include <linux/interrupt.h>
 #include <linux/phy/phy.h>
+#include <linux/workqueue.h>
 
 #if defined(CONFIG_ARCH_DMA_ADDR_T_64BIT) || defined(CONFIG_MACB_USE_HWSTAMP)
 #define MACB_EXT_DESC
@@ -1330,7 +1331,7 @@ struct macb {
 	spinlock_t rx_fs_lock;
 	unsigned int max_tuples;
 
-	struct tasklet_struct	hresp_err_tasklet;
+	struct work_struct	hresp_err_bh_work;
 
 	int	rx_bd_rd_prefetch;
 	int	tx_bd_rd_prefetch;

drivers/net/ethernet/cadence/macb_main.c

@@ -1792,9 +1792,9 @@ static int macb_tx_poll(struct napi_struct *napi, int budget)
 	return work_done;
 }
 
-static void macb_hresp_error_task(struct tasklet_struct *t)
+static void macb_hresp_error_task(struct work_struct *work)
 {
-	struct macb *bp = from_tasklet(bp, t, hresp_err_tasklet);
+	struct macb *bp = from_work(bp, work, hresp_err_bh_work);
 	struct net_device *dev = bp->dev;
 	struct macb_queue *queue;
 	unsigned int q;
@@ -1994,7 +1994,7 @@ static irqreturn_t macb_interrupt(int irq, void *dev_id)
 		}
 
 		if (status & MACB_BIT(HRESP)) {
-			tasklet_schedule(&bp->hresp_err_tasklet);
+			queue_work(system_bh_wq, &bp->hresp_err_bh_work);
 			netdev_err(dev, "DMA bus error: HRESP not OK\n");
 
 			if (bp->caps & MACB_CAPS_ISR_CLEAR_ON_WRITE)
@@ -5172,7 +5172,7 @@ static int macb_probe(struct platform_device *pdev)
 		goto err_out_unregister_mdio;
 	}
 
-	tasklet_setup(&bp->hresp_err_tasklet, macb_hresp_error_task);
+	INIT_WORK(&bp->hresp_err_bh_work, macb_hresp_error_task);
 
 	netdev_info(dev, "Cadence %s rev 0x%08x at 0x%08lx irq %d (%pM)\n",
 		    macb_is_gem(bp) ? "GEM" : "MACB", macb_readl(bp, MID),
@@ -5216,7 +5216,7 @@ static void macb_remove(struct platform_device *pdev)
 		mdiobus_free(bp->mii_bus);
 
 		unregister_netdev(dev);
-		tasklet_kill(&bp->hresp_err_tasklet);
+		cancel_work_sync(&bp->hresp_err_bh_work);
 		pm_runtime_disable(&pdev->dev);
 		pm_runtime_dont_use_autosuspend(&pdev->dev);
 		if (!pm_runtime_suspended(&pdev->dev)) {