diff mbox series

[net-next,v2,11/17] ethernet: ucc_geth: don't statically allocate eight ucc_geth_info

Message ID 20210119150802.19997-12-rasmus.villemoes@prevas.dk (mailing list archive)
State Accepted
Commit baff4311c40ddae7bfc144dc628d4b11c19f0366
Delegated to: Netdev Maintainers
Headers show
Series ucc_geth improvements | expand

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Context Check Description
netdev/cover_letter success Link
netdev/fixes_present success Link
netdev/patch_count fail Series longer than 15 patches
netdev/tree_selection success Clearly marked for net-next
netdev/subject_prefix success Link
netdev/cc_maintainers warning 1 maintainers not CCed: linuxppc-dev@lists.ozlabs.org
netdev/source_inline success Was 0 now: 0
netdev/verify_signedoff success Link
netdev/module_param success Was 0 now: 0
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/verify_fixes success Link
netdev/checkpatch warning CHECK: Comparison to NULL could be written "!ug_info"
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/header_inline success Link
netdev/stable success Stable not CCed

Commit Message

Rasmus Villemoes Jan. 19, 2021, 3:07 p.m. UTC
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@prevas.dk>
---
 drivers/net/ethernet/freescale/ucc_geth.c | 32 +++++++++--------------
 1 file changed, 12 insertions(+), 20 deletions(-)

Comments

Christophe Leroy Jan. 20, 2021, 7:02 a.m. UTC | #1
Le 19/01/2021 à 16:07, 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@prevas.dk>
> ---
>   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 65ef7ae38912..67b93d60243e 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)
>   {
> @@ -3715,25 +3713,23 @@ 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);

What about using devm_kmalloc() and avoid those kfree and associated goto ?


> +	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);
Rasmus Villemoes Jan. 20, 2021, 11:25 a.m. UTC | #2
On 20/01/2021 08.02, Christophe Leroy wrote:
>
>> @@ -3715,25 +3713,23 @@ 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);
> 
> What about using devm_kmalloc() and avoid those kfree and associated goto ?

I already replied to that: I'd rather not mix kmalloc() and
devm_kmalloc() as that makes it much harder to reason about the order in
which stuff gets deallocated. But sure, if you insist.

Rasmus
Christophe Leroy Jan. 20, 2021, 11:30 a.m. UTC | #3
Le 20/01/2021 à 12:25, Rasmus Villemoes a écrit :
> On 20/01/2021 08.02, Christophe Leroy wrote:
>>
>>> @@ -3715,25 +3713,23 @@ 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);
>>
>> What about using devm_kmalloc() and avoid those kfree and associated goto ?
> 
> I already replied to that: I'd rather not mix kmalloc() and
> devm_kmalloc() as that makes it much harder to reason about the order in
> which stuff gets deallocated. But sure, if you insist.
> 

I didn't remember I already did the same comment, sorry.

Christophe
diff mbox series

Patch

diff --git a/drivers/net/ethernet/freescale/ucc_geth.c b/drivers/net/ethernet/freescale/ucc_geth.c
index 65ef7ae38912..67b93d60243e 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)
 {
@@ -3715,25 +3713,23 @@  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);
+	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);
@@ -3746,7 +3742,7 @@  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);
 	}
 
@@ -3877,6 +3873,8 @@  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;
 }
@@ -3893,6 +3891,7 @@  static int ucc_geth_remove(struct platform_device* ofdev)
 		of_phy_deregister_fixed_link(np);
 	of_node_put(ugeth->ug_info->tbi_node);
 	of_node_put(ugeth->ug_info->phy_node);
+	kfree(ugeth->ug_info);
 	free_netdev(dev);
 
 	return 0;
@@ -3921,17 +3920,10 @@  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)