From: Wang Qing <[email protected]>
do_div() does a 64-by-32 division.
When the divisor is u64, do_div() truncates it to 32 bits, this means it
can test non-zero and be truncated to zero for division.
fix do_div.cocci warning:
do_div() does a 64-by-32 division, please consider using div64_u64 instead.
Signed-off-by: Wang Qing <[email protected]>
---
drivers/net/ethernet/cavium/liquidio/lio_main.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/cavium/liquidio/lio_main.c b/drivers/net/ethernet/cavium/liquidio/lio_main.c
index ba28aa4..8e07192
--- a/drivers/net/ethernet/cavium/liquidio/lio_main.c
+++ b/drivers/net/ethernet/cavium/liquidio/lio_main.c
@@ -1539,7 +1539,7 @@ static int liquidio_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
* compute the delta in terms of coprocessor clocks.
*/
delta = (u64)ppb << 32;
- do_div(delta, oct->coproc_clock_rate);
+ div64_u64(delta, oct->coproc_clock_rate);
spin_lock_irqsave(&lio->ptp_lock, flags);
comp = lio_pci_readq(oct, CN6XXX_MIO_PTP_CLOCK_COMP);
@@ -1672,7 +1672,7 @@ static void liquidio_ptp_init(struct octeon_device *oct)
u64 clock_comp, cfg;
clock_comp = (u64)NSEC_PER_SEC << 32;
- do_div(clock_comp, oct->coproc_clock_rate);
+ div64_u64(clock_comp, oct->coproc_clock_rate);
lio_pci_writeq(oct, clock_comp, CN6XXX_MIO_PTP_CLOCK_COMP);
/* Enable */
--
2.7.4
Hello:
This patch was applied to netdev/net-next.git (master)
by David S. Miller <[email protected]>:
On Wed, 9 Feb 2022 00:39:19 -0800 you wrote:
> From: Wang Qing <[email protected]>
>
> do_div() does a 64-by-32 division.
> When the divisor is u64, do_div() truncates it to 32 bits, this means it
> can test non-zero and be truncated to zero for division.
>
> fix do_div.cocci warning:
> do_div() does a 64-by-32 division, please consider using div64_u64 instead.
>
> [...]
Here is the summary with links:
- net: ethernet: cavium: use div64_u64() instead of do_div()
https://git.kernel.org/netdev/net-next/c/038fcdaf0470
You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html
Le 09/02/2022 à 09:39, Qing Wang a écrit :
> From: Wang Qing <[email protected]>
>
> do_div() does a 64-by-32 division.
> When the divisor is u64, do_div() truncates it to 32 bits, this means it
> can test non-zero and be truncated to zero for division.
>
> fix do_div.cocci warning:
> do_div() does a 64-by-32 division, please consider using div64_u64 instead.
>
> Signed-off-by: Wang Qing <[email protected]>
> ---
> drivers/net/ethernet/cavium/liquidio/lio_main.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/ethernet/cavium/liquidio/lio_main.c b/drivers/net/ethernet/cavium/liquidio/lio_main.c
> index ba28aa4..8e07192
> --- a/drivers/net/ethernet/cavium/liquidio/lio_main.c
> +++ b/drivers/net/ethernet/cavium/liquidio/lio_main.c
> @@ -1539,7 +1539,7 @@ static int liquidio_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
> * compute the delta in terms of coprocessor clocks.
> */
> delta = (u64)ppb << 32;
> - do_div(delta, oct->coproc_clock_rate);
> + div64_u64(delta, oct->coproc_clock_rate);
>
> spin_lock_irqsave(&lio->ptp_lock, flags);
> comp = lio_pci_readq(oct, CN6XXX_MIO_PTP_CLOCK_COMP);
> @@ -1672,7 +1672,7 @@ static void liquidio_ptp_init(struct octeon_device *oct)
> u64 clock_comp, cfg;
>
> clock_comp = (u64)NSEC_PER_SEC << 32;
> - do_div(clock_comp, oct->coproc_clock_rate);
> + div64_u64(clock_comp, oct->coproc_clock_rate);
> lio_pci_writeq(oct, clock_comp, CN6XXX_MIO_PTP_CLOCK_COMP);
>
> /* Enable */
I think that all your recent patches about such conversions are broken.
See [1] were it was already reported that do_div() and div64_u64() don't
have the same calling convention.
Looks that div64_u64() and div64_ul() works the same way.
CJ
[1]:
https://lore.kernel.org/linux-kernel/[email protected]/
Le 09/02/2022 à 14:30, [email protected] a écrit :
> Hello:
>
> This patch was applied to netdev/net-next.git (master)
> by David S. Miller <[email protected]>:
>
> On Wed, 9 Feb 2022 00:39:19 -0800 you wrote:
>> From: Wang Qing <[email protected]>
>>
>> do_div() does a 64-by-32 division.
>> When the divisor is u64, do_div() truncates it to 32 bits, this means it
>> can test non-zero and be truncated to zero for division.
>>
>> fix do_div.cocci warning:
>> do_div() does a 64-by-32 division, please consider using div64_u64 instead.
>>
>> [...]
>
> Here is the summary with links:
> - net: ethernet: cavium: use div64_u64() instead of do_div()
> https://git.kernel.org/netdev/net-next/c/038fcdaf0470
>
> You are awesome, thank you!
Hi,
I think that this patch should be reverted because do_div() and
div64_u64() don't have the same calling convention.
See [1]
[1]:
https://lore.kernel.org/linux-kernel/[email protected]/
CJ
On Wed, 9 Feb 2022 21:01:35 +0100 Christophe JAILLET wrote:
> Le 09/02/2022 à 14:30, [email protected] a écrit :
> > Here is the summary with links:
> > - net: ethernet: cavium: use div64_u64() instead of do_div()
> > https://git.kernel.org/netdev/net-next/c/038fcdaf0470
> >
> > You are awesome, thank you!
>
> Hi,
>
> I think that this patch should be reverted because do_div() and
> div64_u64() don't have the same calling convention.
>
> See [1]
>
> [1]:
> https://lore.kernel.org/linux-kernel/[email protected]/
Would you mind sending a revert?
Le 10/02/2022 à 03:01, Jakub Kicinski a écrit :
> On Wed, 9 Feb 2022 21:01:35 +0100 Christophe JAILLET wrote:
>> Le 09/02/2022 à 14:30, [email protected] a écrit :
>>> Here is the summary with links:
>>> - net: ethernet: cavium: use div64_u64() instead of do_div()
>>> https://git.kernel.org/netdev/net-next/c/038fcdaf0470
>>>
>>> You are awesome, thank you!
>>
>> Hi,
>>
>> I think that this patch should be reverted because do_div() and
>> div64_u64() don't have the same calling convention.
>>
>> See [1]
>>
>> [1]:
>> https://lore.kernel.org/linux-kernel/[email protected]/
>
> Would you mind sending a revert?
>
I don't work on net-next, only linux-next.
I can send a revert once it reaches linux-next but I would be better if
it is fixed before that.
CJ