2021-10-24 06:55:47

by Christophe JAILLET

Subject: [PATCH] PCI: endpoint: Use 'bitmap_zalloc()' when applicable

'mem->bitmap' is a bitmap. So use 'bitmap_zalloc()' to simplify code,
improve the semantic and avoid some open-coded arithmetic in allocator
arguments.

Also change the corresponding 'kfree()' into 'bitmap_free()' to keep
consistency.

Finally, while at it, axe the useless 'bitmap' variable and use
'mem->bitmap' directly.

Signed-off-by: Christophe JAILLET <[email protected]>
---
drivers/pci/endpoint/pci-epc-mem.c | 12 ++++--------
1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/drivers/pci/endpoint/pci-epc-mem.c b/drivers/pci/endpoint/pci-epc-mem.c
index a97b56a6d2db..b15a264f19af 100644
--- a/drivers/pci/endpoint/pci-epc-mem.c
+++ b/drivers/pci/endpoint/pci-epc-mem.c
@@ -49,10 +49,8 @@ int pci_epc_multi_mem_init(struct pci_epc *epc,
unsigned int num_windows)
{
struct pci_epc_mem *mem = NULL;
- unsigned long *bitmap = NULL;
unsigned int page_shift;
size_t page_size;
- int bitmap_size;
int pages;
int ret;
int i;
@@ -72,7 +70,6 @@ int pci_epc_multi_mem_init(struct pci_epc *epc,
page_size = PAGE_SIZE;
page_shift = ilog2(page_size);
pages = windows[i].size >> page_shift;
- bitmap_size = BITS_TO_LONGS(pages) * sizeof(long);

mem = kzalloc(sizeof(*mem), GFP_KERNEL);
if (!mem) {
@@ -81,8 +78,8 @@ int pci_epc_multi_mem_init(struct pci_epc *epc,
goto err_mem;
}

- bitmap = kzalloc(bitmap_size, GFP_KERNEL);
- if (!bitmap) {
+ mem->bitmap = bitmap_zalloc(pages, GFP_KERNEL);
+ if (!mem->bitmap) {
ret = -ENOMEM;
kfree(mem);
i--;
@@ -92,7 +89,6 @@ int pci_epc_multi_mem_init(struct pci_epc *epc,
mem->window.phys_base = windows[i].phys_base;
mem->window.size = windows[i].size;
mem->window.page_size = page_size;
- mem->bitmap = bitmap;
mem->pages = pages;
mutex_init(&mem->lock);
epc->windows[i] = mem;
@@ -106,7 +102,7 @@ int pci_epc_multi_mem_init(struct pci_epc *epc,
err_mem:
for (; i >= 0; i--) {
mem = epc->windows[i];
- kfree(mem->bitmap);
+ bitmap_free(mem->bitmap);
kfree(mem);
}
kfree(epc->windows);
@@ -145,7 +141,7 @@ void pci_epc_mem_exit(struct pci_epc *epc)

for (i = 0; i < epc->num_windows; i++) {
mem = epc->windows[i];
- kfree(mem->bitmap);
+ bitmap_free(mem->bitmap);
kfree(mem);
}
kfree(epc->windows);
--
2.30.2

2021-11-07 11:09:30

by Krzysztof Wilczyński

Subject: Re: [PATCH] PCI: endpoint: Use 'bitmap_zalloc()' when applicable

Hi Christophe,

> 'mem->bitmap' is a bitmap. So use 'bitmap_zalloc()' to simplify code,
> improve the semantic and avoid some open-coded arithmetic in allocator
> arguments.
>
> Also change the corresponding 'kfree()' into 'bitmap_free()' to keep
> consistency.

Thank you!

> Finally, while at it, axe the useless 'bitmap' variable and use
> 'mem->bitmap' directly.

Personally, I would keep the bitmap variable - this might be what Bjorn
would also prefer, as I believe he prefers not to store what is a "failed"
state of sorts in a target variable directly, if memory serves me right.

[...]
> @@ -49,10 +49,8 @@ int pci_epc_multi_mem_init(struct pci_epc *epc,
> unsigned int num_windows)
> {
> struct pci_epc_mem *mem = NULL;
> - unsigned long *bitmap = NULL;
> unsigned int page_shift;
> size_t page_size;
> - int bitmap_size;
> int pages;
> int ret;
> int i;
> @@ -72,7 +70,6 @@ int pci_epc_multi_mem_init(struct pci_epc *epc,
> page_size = PAGE_SIZE;
> page_shift = ilog2(page_size);
> pages = windows[i].size >> page_shift;
> - bitmap_size = BITS_TO_LONGS(pages) * sizeof(long);
>
> mem = kzalloc(sizeof(*mem), GFP_KERNEL);
> if (!mem) {
> @@ -81,8 +78,8 @@ int pci_epc_multi_mem_init(struct pci_epc *epc,
> goto err_mem;
> }
>
> - bitmap = kzalloc(bitmap_size, GFP_KERNEL);
> - if (!bitmap) {
> + mem->bitmap = bitmap_zalloc(pages, GFP_KERNEL);
> + if (!mem->bitmap) {
> ret = -ENOMEM;
> kfree(mem);
> i--;
> @@ -92,7 +89,6 @@ int pci_epc_multi_mem_init(struct pci_epc *epc,
> mem->window.phys_base = windows[i].phys_base;
> mem->window.size = windows[i].size;
> mem->window.page_size = page_size;
> - mem->bitmap = bitmap;
> mem->pages = pages;
> mutex_init(&mem->lock);
> epc->windows[i] = mem;
> @@ -106,7 +102,7 @@ int pci_epc_multi_mem_init(struct pci_epc *epc,
> err_mem:
> for (; i >= 0; i--) {
> mem = epc->windows[i];
> - kfree(mem->bitmap);
> + bitmap_free(mem->bitmap);
> kfree(mem);
> }
> kfree(epc->windows);
> @@ -145,7 +141,7 @@ void pci_epc_mem_exit(struct pci_epc *epc)
>
> for (i = 0; i < epc->num_windows; i++) {
> mem = epc->windows[i];
> - kfree(mem->bitmap);
> + bitmap_free(mem->bitmap);
> kfree(mem);
> }
> kfree(epc->windows);

Thank you!

Reviewed-by: Krzysztof Wilczyński <[email protected]>

Krzysztof

2021-11-07 16:10:42

by Christophe JAILLET

Subject: Re: [PATCH] PCI: endpoint: Use 'bitmap_zalloc()' when applicable

Le 06/11/2021 à 23:01, Krzysztof Wilczyński a écrit :
> Hi Christophe,
>
>> 'mem->bitmap' is a bitmap. So use 'bitmap_zalloc()' to simplify code,
>> improve the semantic and avoid some open-coded arithmetic in allocator
>> arguments.
>>
>> Also change the corresponding 'kfree()' into 'bitmap_free()' to keep
>> consistency.
>
> Thank you!
>
>> Finally, while at it, axe the useless 'bitmap' variable and use
>> 'mem->bitmap' directly.
>
> Personally, I would keep the bitmap variable - this might be what Bjorn
> would also prefer, as I believe he prefers not to store what is a "failed"
> state of sorts in a target variable directly, if memory serves me right.

Hi,

mostly a mater of taste.
On another similar patch I got the answer in [1] :).

'mem' is kzalloc'ed, so in case of failure, here we are just replacing
NULL by NULL.

Let me know the preferred style here and if I should send a V2.

CJ

[1]; https://lore.kernel.org/kernel-janitors/20211028164437.GA4045120@p14s/

>
> [...]
>> @@ -49,10 +49,8 @@ int pci_epc_multi_mem_init(struct pci_epc *epc,
>> unsigned int num_windows)
>> {
>> struct pci_epc_mem *mem = NULL;
>> - unsigned long *bitmap = NULL;
>> unsigned int page_shift;
>> size_t page_size;
>> - int bitmap_size;
>> int pages;
>> int ret;
>> int i;
>> @@ -72,7 +70,6 @@ int pci_epc_multi_mem_init(struct pci_epc *epc,
>> page_size = PAGE_SIZE;
>> page_shift = ilog2(page_size);
>> pages = windows[i].size >> page_shift;
>> - bitmap_size = BITS_TO_LONGS(pages) * sizeof(long);
>>
>> mem = kzalloc(sizeof(*mem), GFP_KERNEL);
>> if (!mem) {
>> @@ -81,8 +78,8 @@ int pci_epc_multi_mem_init(struct pci_epc *epc,
>> goto err_mem;
>> }
>>
>> - bitmap = kzalloc(bitmap_size, GFP_KERNEL);
>> - if (!bitmap) {
>> + mem->bitmap = bitmap_zalloc(pages, GFP_KERNEL);
>> + if (!mem->bitmap) {
>> ret = -ENOMEM;
>> kfree(mem);
>> i--;
>> @@ -92,7 +89,6 @@ int pci_epc_multi_mem_init(struct pci_epc *epc,
>> mem->window.phys_base = windows[i].phys_base;
>> mem->window.size = windows[i].size;
>> mem->window.page_size = page_size;
>> - mem->bitmap = bitmap;
>> mem->pages = pages;
>> mutex_init(&mem->lock);
>> epc->windows[i] = mem;
>> @@ -106,7 +102,7 @@ int pci_epc_multi_mem_init(struct pci_epc *epc,
>> err_mem:
>> for (; i >= 0; i--) {
>> mem = epc->windows[i];
>> - kfree(mem->bitmap);
>> + bitmap_free(mem->bitmap);
>> kfree(mem);
>> }
>> kfree(epc->windows);
>> @@ -145,7 +141,7 @@ void pci_epc_mem_exit(struct pci_epc *epc)
>>
>> for (i = 0; i < epc->num_windows; i++) {
>> mem = epc->windows[i];
>> - kfree(mem->bitmap);
>> + bitmap_free(mem->bitmap);
>> kfree(mem);
>> }
>> kfree(epc->windows);
>
> Thank you!
>
> Reviewed-by: Krzysztof Wilczyński <[email protected]>
>
> Krzysztof
>