diff mbox series

kni: fix build on Linux < 3.14

Message ID 20181026214027.29465-1-thomas@monjalon.net (mailing list archive)
State Accepted, archived
Delegated to: Thomas Monjalon
Headers
Series kni: fix build on Linux < 3.14 |

Checks

Context Check Description
ci/checkpatch warning coding style issues
ci/Intel-compilation success Compilation OK

Commit Message

Thomas Monjalon Oct. 26, 2018, 9:40 p.m. UTC 
  The atomic functions smp_load_acquire() and smp_store_release()
were introduced in Linux 3.14. Older kernels miss the functions:

kni_fifo.h:19:2: error:
	implicit declaration of function ‘smp_load_acquire’
kni_fifo.h:30:2: error:
	implicit declaration of function ‘smp_store_release’

The fallback is to drop the atomic barrier, as it was before
the commit below.

Fixes: 711859cd0d07 ("kni: fix kernel FIFO synchronization")

Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
---
 kernel/linux/kni/kni_fifo.h | 7 +++++++
 1 file changed, 7 insertions(+)

Comments

Thomas Monjalon Oct. 26, 2018, 9:56 p.m. UTC | #1 
26/10/2018 23:40, Thomas Monjalon:
> The atomic functions smp_load_acquire() and smp_store_release()
> were introduced in Linux 3.14. Older kernels miss the functions:
> 
> kni_fifo.h:19:2: error:
> 	implicit declaration of function ‘smp_load_acquire’
> kni_fifo.h:30:2: error:
> 	implicit declaration of function ‘smp_store_release’
> 
> The fallback is to drop the atomic barrier, as it was before
> the commit below.
> 
> Fixes: 711859cd0d07 ("kni: fix kernel FIFO synchronization")
> 
> Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
> ---
>  kernel/linux/kni/kni_fifo.h | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> --- a/kernel/linux/kni/kni_fifo.h
> +++ b/kernel/linux/kni/kni_fifo.h

We could add a comment here:
/* Skip some memory barriers on Linux < 3.14 */

> +#ifndef smp_load_acquire
> +#define smp_load_acquire(a) (*(a))
> +#endif
> +#ifndef smp_store_release
> +#define smp_store_release(a, b) *(a) = (b)
> +#endif
Ferruh Yigit Oct. 26, 2018, 10:42 p.m. UTC | #2 
On 10/26/2018 10:56 PM, Thomas Monjalon wrote:
> 26/10/2018 23:40, Thomas Monjalon:
>> The atomic functions smp_load_acquire() and smp_store_release()
>> were introduced in Linux 3.14. Older kernels miss the functions:
>>
>> kni_fifo.h:19:2: error:
>> 	implicit declaration of function ‘smp_load_acquire’
>> kni_fifo.h:30:2: error:
>> 	implicit declaration of function ‘smp_store_release’
>>
>> The fallback is to drop the atomic barrier, as it was before
>> the commit below.
>>
>> Fixes: 711859cd0d07 ("kni: fix kernel FIFO synchronization")
>>
>> Signed-off-by: Thomas Monjalon <thomas@monjalon.net>

Tested-by: Ferruh Yigit <ferruh.yigit@intel.com>
Thomas Monjalon Oct. 26, 2018, 11:25 p.m. UTC | #3 
27/10/2018 00:42, Ferruh Yigit:
> On 10/26/2018 10:56 PM, Thomas Monjalon wrote:
> > 26/10/2018 23:40, Thomas Monjalon:
> >> The atomic functions smp_load_acquire() and smp_store_release()
> >> were introduced in Linux 3.14. Older kernels miss the functions:
> >>
> >> kni_fifo.h:19:2: error:
> >> 	implicit declaration of function ‘smp_load_acquire’
> >> kni_fifo.h:30:2: error:
> >> 	implicit declaration of function ‘smp_store_release’
> >>
> >> The fallback is to drop the atomic barrier, as it was before
> >> the commit below.
> >>
> >> Fixes: 711859cd0d07 ("kni: fix kernel FIFO synchronization")
> >>
> >> Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
> 
> Tested-by: Ferruh Yigit <ferruh.yigit@intel.com>

Applied
diff mbox series

Patch

diff --git a/kernel/linux/kni/kni_fifo.h b/kernel/linux/kni/kni_fifo.h
index 2cb3a4a7b..3c0be311f 100644
--- a/kernel/linux/kni/kni_fifo.h
+++ b/kernel/linux/kni/kni_fifo.h
@@ -8,6 +8,13 @@ 
 
 #include <exec-env/rte_kni_common.h>
 
+#ifndef smp_load_acquire
+#define smp_load_acquire(a) (*(a))
+#endif
+#ifndef smp_store_release
+#define smp_store_release(a, b) *(a) = (b)
+#endif
+
 /**
  * Adds num elements into the fifo. Return the number actually written
  */