mirrors/linux
2
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-08-31 08:15:07 -04:00
Code Issues Packages Projects Releases Wiki Activity

net: macb: allocate tieoff descriptor once across device lifetime

Browse Source 
The tieoff descriptor is a RX DMA descriptor ring of size one. It gets
configured onto queues for Wake-on-LAN during system-wide suspend when
hardware does not support disabling individual queues
(MACB_CAPS_QUEUE_DISABLE).

MACB/GEM driver allocates it alongside the main RX ring
inside macb_alloc() at open. Free is done by macb_free() at close.

Change to allocate once at probe and free on probe failure or device
removal. This makes the tieoff descriptor lifetime much longer,
avoiding repeating coherent buffer allocation on each open/close cycle.

Main benefit: we dissociate its lifetime from the main ring's lifetime.
That way there is less work to be doing on resources (re)alloc. This
currently happens on close/open, but will soon also happen on context
swap operations (set_ringparam, change_mtu, set_channels, etc).

Reviewed-by: Nicolai Buchwitz <nb@tipi-net.de>
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Link: https://patch.msgid.link/20260812-macb-context-v9-6-7ddbf5f715e0@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Théo Lebrun
2026-08-12 10:03:20 +02:00
committed by Jakub Kicinski
parent 2cedfce238
commit 5262eab946
1 changed files with 41 additions and 34 deletions
Download Patch File Download Diff File Expand all files Collapse all files

75
drivers/net/ethernet/cadence/macb_main.c
View File

@@ -2655,12 +2655,6 @@ static void macb_free(struct macb *bp)
unsigned int q;
size_t size;
if (bp->rx_ring_tieoff) {
dma_free_coherent(dev, macb_dma_desc_get_size(bp),
bp->rx_ring_tieoff, bp->rx_ring_tieoff_dma);
bp->rx_ring_tieoff = NULL;
}
bp->macbgem_ops.mog_free_rx_buffers(bp);
size = bp->num_queues * macb_tx_ring_size_per_queue(bp);
@@ -2775,16 +2769,6 @@ static int macb_alloc(struct macb *bp)
if (bp->macbgem_ops.mog_alloc_rx_buffers(bp))
goto out_err;
/* Required for tie off descriptor for PM cases */
if (!(bp->caps & MACB_CAPS_QUEUE_DISABLE)) {
bp->rx_ring_tieoff = dma_alloc_coherent(&bp->pdev->dev,
macb_dma_desc_get_size(bp),
&bp->rx_ring_tieoff_dma,
GFP_KERNEL);
if (!bp->rx_ring_tieoff)
goto out_err;
}
return 0;
out_err:
@@ -2792,19 +2776,6 @@ static int macb_alloc(struct macb *bp)
return -ENOMEM;
}
static void macb_init_tieoff(struct macb *bp)
{
struct macb_dma_desc *desc = bp->rx_ring_tieoff;
if (bp->caps & MACB_CAPS_QUEUE_DISABLE)
return;
/* Setup a wrapping descriptor with no free slots
* (WRAP and USED) to tie off/disable unused RX queues.
*/
macb_set_addr(bp, desc, MACB_BIT(RX_WRAP) | MACB_BIT(RX_USED));
desc->ctrl = 0;
}
static void gem_init_rx_ring(struct macb_queue *queue)
{
queue->rx_tail = 0;
@@ -2832,8 +2803,6 @@ static void gem_init_rings(struct macb *bp)
gem_init_rx_ring(queue);
}
macb_init_tieoff(bp);
}
static void macb_init_rings(struct macb *bp)
@@ -2851,8 +2820,6 @@ static void macb_init_rings(struct macb *bp)
bp->queues[0].tx_head = 0;
bp->queues[0].tx_tail = 0;
desc->ctrl |= MACB_BIT(TX_WRAP);
macb_init_tieoff(bp);
}
static void macb_reset_hw(struct macb *bp)
@@ -5537,6 +5504,38 @@ static int eyeq5_init(struct platform_device *pdev)
return ret;
}
static int macb_alloc_tieoff(struct macb *bp)
{
/* Tieoff is a workaround in case HW cannot disable queues, for PM. */
if (bp->caps & MACB_CAPS_QUEUE_DISABLE)
return 0;
bp->rx_ring_tieoff = dma_alloc_coherent(&bp->pdev->dev,
macb_dma_desc_get_size(bp),
&bp->rx_ring_tieoff_dma,
GFP_KERNEL);
if (!bp->rx_ring_tieoff)
return -ENOMEM;
macb_set_addr(bp, bp->rx_ring_tieoff,
MACB_BIT(RX_WRAP) | MACB_BIT(RX_USED));
bp->rx_ring_tieoff->ctrl = 0;
return 0;
}
static void macb_free_tieoff(struct macb *bp)
{
if (!bp->rx_ring_tieoff)
return;
dma_free_coherent(&bp->pdev->dev, macb_dma_desc_get_size(bp),
bp->rx_ring_tieoff,
bp->rx_ring_tieoff_dma);
bp->rx_ring_tieoff = NULL;
}
static const struct macb_usrio_config mpfs_usrio = {
.tsu_source = 0,
};
@@ -5946,10 +5945,14 @@ static int macb_probe(struct platform_device *pdev)
netif_carrier_off(netdev);
err = macb_alloc_tieoff(bp);
if (err)
goto err_out_unregister_mdio;
err = register_netdev(netdev);
if (err) {
dev_err(&pdev->dev, "Cannot register net device, aborting.\n");
goto err_out_unregister_mdio;
goto err_out_free_tieoff;
}
INIT_WORK(&bp->hresp_err_bh_work, macb_hresp_error_task);
@@ -5963,6 +5966,9 @@ static int macb_probe(struct platform_device *pdev)
return 0;
err_out_free_tieoff:
macb_free_tieoff(bp);
err_out_unregister_mdio:
mdiobus_unregister(bp->mii_bus);
mdiobus_free(bp->mii_bus);
@@ -5992,6 +5998,7 @@ static void macb_remove(struct platform_device *pdev)
if (netdev) {
bp = netdev_priv(netdev);
unregister_netdev(netdev);
macb_free_tieoff(bp);
phy_exit(bp->phy);
mdiobus_unregister(bp->mii_bus);
mdiobus_free(bp->mii_bus);