Patch "net: bcmasp: fix memory leak when bringing down interface" has been added to the 6.8-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    net: bcmasp: fix memory leak when bringing down interface

to the 6.8-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     net-bcmasp-fix-memory-leak-when-bringing-down-interf.patch
and it can be found in the queue-6.8 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 65deca92de124fb184efc5cfa711b26eac5704c6
Author: Justin Chen <justin.chen@xxxxxxxxxxxx>
Date:   Thu Apr 18 11:05:41 2024 -0700

    net: bcmasp: fix memory leak when bringing down interface
    
    [ Upstream commit 9f898fc2c31fbf0ac5ecd289f528a716464cb005 ]
    
    When bringing down the TX rings we flush the rings but forget to
    reclaimed the flushed packets. This leads to a memory leak since we
    do not free the dma mapped buffers. This also leads to tx control
    block corruption when bringing down the interface for power
    management.
    
    Fixes: 490cb412007d ("net: bcmasp: Add support for ASP2.0 Ethernet controller")
    Signed-off-by: Justin Chen <justin.chen@xxxxxxxxxxxx>
    Acked-by: Florian Fainelli <florian.fainelli@xxxxxxxxxxxx>
    Reviewed-by: Simon Horman <horms@xxxxxxxxxx>
    Link: https://lore.kernel.org/r/20240418180541.2271719-1-justin.chen@xxxxxxxxxxxx
    Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/net/ethernet/broadcom/asp2/bcmasp_intf.c b/drivers/net/ethernet/broadcom/asp2/bcmasp_intf.c
index 78901e2e73032..529172a87ae50 100644
--- a/drivers/net/ethernet/broadcom/asp2/bcmasp_intf.c
+++ b/drivers/net/ethernet/broadcom/asp2/bcmasp_intf.c
@@ -435,10 +435,8 @@ static void umac_init(struct bcmasp_intf *intf)
 	umac_wl(intf, 0x800, UMC_RX_MAX_PKT_SZ);
 }
 
-static int bcmasp_tx_poll(struct napi_struct *napi, int budget)
+static int bcmasp_tx_reclaim(struct bcmasp_intf *intf)
 {
-	struct bcmasp_intf *intf =
-		container_of(napi, struct bcmasp_intf, tx_napi);
 	struct bcmasp_intf_stats64 *stats = &intf->stats64;
 	struct device *kdev = &intf->parent->pdev->dev;
 	unsigned long read, released = 0;
@@ -481,10 +479,16 @@ static int bcmasp_tx_poll(struct napi_struct *napi, int budget)
 							DESC_RING_COUNT);
 	}
 
-	/* Ensure all descriptors have been written to DRAM for the hardware
-	 * to see updated contents.
-	 */
-	wmb();
+	return released;
+}
+
+static int bcmasp_tx_poll(struct napi_struct *napi, int budget)
+{
+	struct bcmasp_intf *intf =
+		container_of(napi, struct bcmasp_intf, tx_napi);
+	int released = 0;
+
+	released = bcmasp_tx_reclaim(intf);
 
 	napi_complete(&intf->tx_napi);
 
@@ -796,6 +800,7 @@ static int bcmasp_init_tx(struct bcmasp_intf *intf)
 
 	intf->tx_spb_index = 0;
 	intf->tx_spb_clean_index = 0;
+	memset(intf->tx_cbs, 0, sizeof(struct bcmasp_tx_cb) * DESC_RING_COUNT);
 
 	netif_napi_add_tx(intf->ndev, &intf->tx_napi, bcmasp_tx_poll);
 
@@ -906,6 +911,8 @@ static void bcmasp_netif_deinit(struct net_device *dev)
 	} while (timeout-- > 0);
 	tx_spb_dma_wl(intf, 0x0, TX_SPB_DMA_FIFO_CTRL);
 
+	bcmasp_tx_reclaim(intf);
+
 	umac_enable_set(intf, UMC_CMD_TX_EN, 0);
 
 	phy_stop(dev->phydev);