Re: [PATCH 14/20] ethernet: ucc_geth: don't statically allocate eight ucc_geth_info

From: Christophe Leroy
Date: Tue Dec 08 2020 - 10:14:05 EST




Le 05/12/2020 à 20:17, Rasmus Villemoes a écrit :
struct ucc_geth_info is somewhat large, and on systems with only one
or two UCC instances, that just wastes a few KB of memory. So
allocate and populate a chunk of memory at probe time instead of
initializing them all during driver init.

Note that the existing "ug_info == NULL" check was dead code, as the
address of some static array element can obviously never be NULL.

Signed-off-by: Rasmus Villemoes <rasmus.villemoes@xxxxxxxxx>
---
drivers/net/ethernet/freescale/ucc_geth.c | 32 +++++++++--------------
1 file changed, 12 insertions(+), 20 deletions(-)

diff --git a/drivers/net/ethernet/freescale/ucc_geth.c b/drivers/net/ethernet/freescale/ucc_geth.c
index a06744d8b4af..273342233bba 100644
--- a/drivers/net/ethernet/freescale/ucc_geth.c
+++ b/drivers/net/ethernet/freescale/ucc_geth.c
@@ -157,8 +157,6 @@ static const struct ucc_geth_info ugeth_primary_info = {
.riscRx = QE_RISC_ALLOCATION_RISC1_AND_RISC2,
};
-static struct ucc_geth_info ugeth_info[8];
-
#ifdef DEBUG
static void mem_disp(u8 *addr, int size)
{
@@ -3714,25 +3712,23 @@ static int ucc_geth_probe(struct platform_device* ofdev)
if ((ucc_num < 0) || (ucc_num > 7))
return -ENODEV;
- ug_info = &ugeth_info[ucc_num];
- if (ug_info == NULL) {
- if (netif_msg_probe(&debug))
- pr_err("[%d] Missing additional data!\n", ucc_num);
- return -ENODEV;
- }
+ ug_info = kmalloc(sizeof(*ug_info), GFP_KERNEL);

Could we use dev_kmalloc() instead, to avoid the freeing on the wait out and the err_free_info: path ?

+ if (ug_info == NULL)
+ return -ENOMEM;
+ memcpy(ug_info, &ugeth_primary_info, sizeof(*ug_info));
ug_info->uf_info.ucc_num = ucc_num;
err = ucc_geth_parse_clock(np, "rx", &ug_info->uf_info.rx_clock);
if (err)
- return err;
+ goto err_free_info;
err = ucc_geth_parse_clock(np, "tx", &ug_info->uf_info.tx_clock);
if (err)
- return err;
+ goto err_free_info;
err = of_address_to_resource(np, 0, &res);
if (err)
- return -EINVAL;
+ goto err_free_info;
ug_info->uf_info.regs = res.start;
ug_info->uf_info.irq = irq_of_parse_and_map(np, 0);
@@ -3745,7 +3741,7 @@ static int ucc_geth_probe(struct platform_device* ofdev)
*/
err = of_phy_register_fixed_link(np);
if (err)
- return err;
+ goto err_free_info;
ug_info->phy_node = of_node_get(np);
}
@@ -3876,6 +3872,8 @@ static int ucc_geth_probe(struct platform_device* ofdev)
of_phy_deregister_fixed_link(np);
of_node_put(ug_info->tbi_node);
of_node_put(ug_info->phy_node);
+err_free_info:
+ kfree(ug_info);
return err;
}
@@ -3886,6 +3884,7 @@ static int ucc_geth_remove(struct platform_device* ofdev)
struct ucc_geth_private *ugeth = netdev_priv(dev);
struct device_node *np = ofdev->dev.of_node;
+ kfree(ugeth->ug_info);
ucc_geth_memclean(ugeth);
if (of_phy_is_fixed_link(np))
of_phy_deregister_fixed_link(np);
@@ -3920,17 +3919,10 @@ static struct platform_driver ucc_geth_driver = {
static int __init ucc_geth_init(void)
{
- int i, ret;
-
if (netif_msg_drv(&debug))
pr_info(DRV_DESC "\n");
- for (i = 0; i < 8; i++)
- memcpy(&(ugeth_info[i]), &ugeth_primary_info,
- sizeof(ugeth_primary_info));
-
- ret = platform_driver_register(&ucc_geth_driver);
- return ret;
+ return platform_driver_register(&ucc_geth_driver);
}
static void __exit ucc_geth_exit(void)