[dpdk-dev] [PATCH v3] eal/ppc64: improve rte_rdtsc() with __ppc_get_timebase()

[dpdk-dev] [PATCH v3] eal/ppc64: improve rte_rdtsc() with __ppc_get_timebase()

[Thinh Tran]

  __ppc_get_timebase() reads and returns the current value of the Time 
  Base Register. It's more efficient as it uses the processor’s time  
  base facility directly 

  the DPDK on FreeBSD currently is not supported on Powerpc64, it should
  be safe to include the sys/platform/ppc.h


Signed-off-by: Thinh Tran <thinhtr@linux.vnet.ibm.com>
---
 .../common/include/arch/ppc_64/rte_cycles.h   | 28 ++-----------------
 1 file changed, 2 insertions(+), 26 deletions(-)

diff --git a/lib/librte_eal/common/include/arch/ppc_64/rte_cycles.h b/lib/librte_eal/common/include/arch/ppc_64/rte_cycles.h
index 8f2e98642..871f9b6e4 100644
--- a/lib/librte_eal/common/include/arch/ppc_64/rte_cycles.h
+++ b/lib/librte_eal/common/include/arch/ppc_64/rte_cycles.h
@@ -14,6 +14,7 @@ extern "C" {
 
 #include <rte_byteorder.h>
 #include <rte_common.h>
+#include <sys/platform/ppc.h>
 
 /**
  * Read the time base register.
@@ -24,32 +25,7 @@ extern "C" {
 static inline uint64_t
 rte_rdtsc(void)
 {
-	union {
-		uint64_t tsc_64;
-		RTE_STD_C11
-		struct {
-#if RTE_BYTE_ORDER == RTE_BIG_ENDIAN
-			uint32_t hi_32;
-			uint32_t lo_32;
-#else
-			uint32_t lo_32;
-			uint32_t hi_32;
-#endif
-		};
-	} tsc;
-	uint32_t tmp;
-
-	asm volatile(
-			"0:\n"
-			"mftbu   %[hi32]\n"
-			"mftb    %[lo32]\n"
-			"mftbu   %[tmp]\n"
-			"cmpw    %[tmp],%[hi32]\n"
-			"bne     0b\n"
-			: [hi32] "=r"(tsc.hi_32), [lo32] "=r"(tsc.lo_32),
-			[tmp] "=r"(tmp)
-		    );
-	return tsc.tsc_64;
+	return __ppc_get_timebase();
 }
 
 static inline uint64_t
-- 
2.17.0

Re: [dpdk-dev] [PATCH v3] eal/ppc64: improve rte_rdtsc() with __ppc_get_timebase()

[Thomas Monjalon]

Any review please?

25/03/2020 01:13, Thinh Tran:
>   __ppc_get_timebase() reads and returns the current value of the Time 
>   Base Register. It's more efficient as it uses the processor’s time  
>   base facility directly 
> 
>   the DPDK on FreeBSD currently is not supported on Powerpc64, it should
>   be safe to include the sys/platform/ppc.h
> 
> 
> Signed-off-by: Thinh Tran <thinhtr@linux.vnet.ibm.com>
> ---
>  .../common/include/arch/ppc_64/rte_cycles.h   | 28 ++-----------------
>  1 file changed, 2 insertions(+), 26 deletions(-)
> 
> diff --git a/lib/librte_eal/common/include/arch/ppc_64/rte_cycles.h b/lib/librte_eal/common/include/arch/ppc_64/rte_cycles.h
> index 8f2e98642..871f9b6e4 100644
> --- a/lib/librte_eal/common/include/arch/ppc_64/rte_cycles.h
> +++ b/lib/librte_eal/common/include/arch/ppc_64/rte_cycles.h
> @@ -14,6 +14,7 @@ extern "C" {
>  
>  #include <rte_byteorder.h>
>  #include <rte_common.h>
> +#include <sys/platform/ppc.h>
>  
>  /**
>   * Read the time base register.
> @@ -24,32 +25,7 @@ extern "C" {
>  static inline uint64_t
>  rte_rdtsc(void)
>  {
> -	union {
> -		uint64_t tsc_64;
> -		RTE_STD_C11
> -		struct {
> -#if RTE_BYTE_ORDER == RTE_BIG_ENDIAN
> -			uint32_t hi_32;
> -			uint32_t lo_32;
> -#else
> -			uint32_t lo_32;
> -			uint32_t hi_32;
> -#endif
> -		};
> -	} tsc;
> -	uint32_t tmp;
> -
> -	asm volatile(
> -			"0:\n"
> -			"mftbu   %[hi32]\n"
> -			"mftb    %[lo32]\n"
> -			"mftbu   %[tmp]\n"
> -			"cmpw    %[tmp],%[hi32]\n"
> -			"bne     0b\n"
> -			: [hi32] "=r"(tsc.hi_32), [lo32] "=r"(tsc.lo_32),
> -			[tmp] "=r"(tmp)
> -		    );
> -	return tsc.tsc_64;
> +	return __ppc_get_timebase();
>  }
>  
>  static inline uint64_t

Re: [dpdk-dev] [PATCH v3] eal/ppc64: improve rte_rdtsc() with __ppc_get_timebase()

[David Christensen]

On 3/24/20 5:13 PM, Thinh Tran wrote:
>    __ppc_get_timebase() reads and returns the current value of the Time
>    Base Register. It's more efficient as it uses the processor’s time
>    base facility directly
> 
>    the DPDK on FreeBSD currently is not supported on Powerpc64, it should
>    be safe to include the sys/platform/ppc.h
> 
> 
> Signed-off-by: Thinh Tran <thinhtr@linux.vnet.ibm.com>
> ---
>   .../common/include/arch/ppc_64/rte_cycles.h   | 28 ++-----------------
>   1 file changed, 2 insertions(+), 26 deletions(-)
> 
> diff --git a/lib/librte_eal/common/include/arch/ppc_64/rte_cycles.h b/lib/librte_eal/common/include/arch/ppc_64/rte_cycles.h
> index 8f2e98642..871f9b6e4 100644
> --- a/lib/librte_eal/common/include/arch/ppc_64/rte_cycles.h
> +++ b/lib/librte_eal/common/include/arch/ppc_64/rte_cycles.h

Patched file location has moved, now lib/librte_eal/ppc/include/* as a 
result of commit a1b6cda16a07, otherwise it's good to go.

Reviewed-by: David Christensen (drc@linux.vnet.ibm.com)

Re: [dpdk-dev] [PATCH v3] eal/ppc64: improve rte_rdtsc() with __ppc_get_timebase()

[David Marchand]

On Wed, Mar 25, 2020 at 1:17 AM Thinh Tran <thinhtr@linux.vnet.ibm.com> wrote:
>
>   __ppc_get_timebase() reads and returns the current value of the Time
>   Base Register. It's more efficient as it uses the processor’s time
>   base facility directly
>
>   the DPDK on FreeBSD currently is not supported on Powerpc64, it should
>   be safe to include the sys/platform/ppc.h
>
>
> Signed-off-by: Thinh Tran <thinhtr@linux.vnet.ibm.com>

Reviewed-by: David Christensen <drc@linux.vnet.ibm.com>

Applied, thanks.

-- 
David Marchand