diff mbox series

hw/block/nvme: Simplify timestamp sum

Message ID 20201002075716.1657849-1-philmd@redhat.com
State New
Headers show
Series hw/block/nvme: Simplify timestamp sum | expand

Commit Message

Philippe Mathieu-Daudé Oct. 2, 2020, 7:57 a.m. UTC
As the 'timestamp' variable is declared as a 48-bit bitfield,
we do not need to wrap the sum result.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
 hw/block/nvme.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

Comments

Klaus Jensen Oct. 2, 2020, 8:01 a.m. UTC | #1
On Oct  2 09:57, Philippe Mathieu-Daudé wrote:
> As the 'timestamp' variable is declared as a 48-bit bitfield,

> we do not need to wrap the sum result.

> 

> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>


Reviewed-by: Klaus Jensen <k.jensen@samsung.com>


> ---

>  hw/block/nvme.c | 7 +------

>  1 file changed, 1 insertion(+), 6 deletions(-)

> 

> diff --git a/hw/block/nvme.c b/hw/block/nvme.c

> index 63078f6009..44fa5b9076 100644

> --- a/hw/block/nvme.c

> +++ b/hw/block/nvme.c

> @@ -1280,12 +1280,7 @@ static inline uint64_t nvme_get_timestamp(const NvmeCtrl *n)

>  

>      union nvme_timestamp ts;

>      ts.all = 0;

> -

> -    /*

> -     * If the sum of the Timestamp value set by the host and the elapsed

> -     * time exceeds 2^48, the value returned should be reduced modulo 2^48.

> -     */

> -    ts.timestamp = (n->host_timestamp + elapsed_time) & 0xffffffffffff;

> +    ts.timestamp = n->host_timestamp + elapsed_time;

>  

>      /* If the host timestamp is non-zero, set the timestamp origin */

>      ts.origin = n->host_timestamp ? 0x01 : 0x00;

> -- 

> 2.26.2

> 

> 


-- 
One of us - No more doubt, silence or taboo about mental illness.
Laurent Vivier Oct. 12, 2020, 12:24 p.m. UTC | #2
Le 02/10/2020 à 09:57, Philippe Mathieu-Daudé a écrit :
> As the 'timestamp' variable is declared as a 48-bit bitfield,

> we do not need to wrap the sum result.

> 

> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>

> ---

>  hw/block/nvme.c | 7 +------

>  1 file changed, 1 insertion(+), 6 deletions(-)

> 

> diff --git a/hw/block/nvme.c b/hw/block/nvme.c

> index 63078f6009..44fa5b9076 100644

> --- a/hw/block/nvme.c

> +++ b/hw/block/nvme.c

> @@ -1280,12 +1280,7 @@ static inline uint64_t nvme_get_timestamp(const NvmeCtrl *n)

>  

>      union nvme_timestamp ts;

>      ts.all = 0;

> -

> -    /*

> -     * If the sum of the Timestamp value set by the host and the elapsed

> -     * time exceeds 2^48, the value returned should be reduced modulo 2^48.

> -     */

> -    ts.timestamp = (n->host_timestamp + elapsed_time) & 0xffffffffffff;

> +    ts.timestamp = n->host_timestamp + elapsed_time;

>  

>      /* If the host timestamp is non-zero, set the timestamp origin */

>      ts.origin = n->host_timestamp ? 0x01 : 0x00;

> 


Applied to my trivial-patches branch.

Thanks,
Laurent
diff mbox series

Patch

diff --git a/hw/block/nvme.c b/hw/block/nvme.c
index 63078f6009..44fa5b9076 100644
--- a/hw/block/nvme.c
+++ b/hw/block/nvme.c
@@ -1280,12 +1280,7 @@  static inline uint64_t nvme_get_timestamp(const NvmeCtrl *n)
 
     union nvme_timestamp ts;
     ts.all = 0;
-
-    /*
-     * If the sum of the Timestamp value set by the host and the elapsed
-     * time exceeds 2^48, the value returned should be reduced modulo 2^48.
-     */
-    ts.timestamp = (n->host_timestamp + elapsed_time) & 0xffffffffffff;
+    ts.timestamp = n->host_timestamp + elapsed_time;
 
     /* If the host timestamp is non-zero, set the timestamp origin */
     ts.origin = n->host_timestamp ? 0x01 : 0x00;