[PATCH] powerpc/ps3: Use cpu_relax() in ps3_create_spu()

[PATCH] powerpc/ps3: Use cpu_relax() in ps3_create_spu()

[Thorsten Blum]

Use cpu_relax() to wait for the execution status SPE_EX_STATE_EXECUTED.
Drop the comments while at it.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
---
 arch/powerpc/platforms/ps3/spu.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/platforms/ps3/spu.c b/arch/powerpc/platforms/ps3/spu.c
index e4e0b45e1b9d..8545c72385de 100644
--- a/arch/powerpc/platforms/ps3/spu.c
+++ b/arch/powerpc/platforms/ps3/spu.c
@@ -13,6 +13,7 @@
 #include <linux/export.h>
 #include <linux/io.h>
 #include <linux/mm.h>
+#include <linux/processor.h>
 
 #include <asm/spu.h>
 #include <asm/spu_priv1.h>
@@ -363,12 +364,9 @@ static int __init ps3_create_spu(struct spu *spu, void *data)
 	if (result)
 		goto fail_enable;
 
-	/* Make sure the spu is in SPE_EX_STATE_EXECUTED. */
-
-	/* need something better here!!! */
-	while (in_be64(&spu_pdata(spu)->shadow->spe_execution_status)
-		!= SPE_EX_STATE_EXECUTED)
-		(void)0;
+	while (in_be64(&spu_pdata(spu)->shadow->spe_execution_status) !=
+	       SPE_EX_STATE_EXECUTED)
+		cpu_relax();
 
 	return result;
 

Re: [PATCH] powerpc/ps3: Use cpu_relax() in ps3_create_spu()

[Christophe Leroy (CS GROUP)]

Le 21/07/2026 à 01:11, Thorsten Blum a écrit :
> Use cpu_relax() to wait for the execution status SPE_EX_STATE_EXECUTED.
> Drop the comments while at it.
> 
> Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>

Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>

> ---
>   arch/powerpc/platforms/ps3/spu.c | 10 ++++------
>   1 file changed, 4 insertions(+), 6 deletions(-)
> 
> diff --git a/arch/powerpc/platforms/ps3/spu.c b/arch/powerpc/platforms/ps3/spu.c
> index e4e0b45e1b9d..8545c72385de 100644
> --- a/arch/powerpc/platforms/ps3/spu.c
> +++ b/arch/powerpc/platforms/ps3/spu.c
> @@ -13,6 +13,7 @@
>   #include <linux/export.h>
>   #include <linux/io.h>
>   #include <linux/mm.h>
> +#include <linux/processor.h>
>   
>   #include <asm/spu.h>
>   #include <asm/spu_priv1.h>
> @@ -363,12 +364,9 @@ static int __init ps3_create_spu(struct spu *spu, void *data)
>   	if (result)
>   		goto fail_enable;
>   
> -	/* Make sure the spu is in SPE_EX_STATE_EXECUTED. */
> -
> -	/* need something better here!!! */
> -	while (in_be64(&spu_pdata(spu)->shadow->spe_execution_status)
> -		!= SPE_EX_STATE_EXECUTED)
> -		(void)0;
> +	while (in_be64(&spu_pdata(spu)->shadow->spe_execution_status) !=
> +	       SPE_EX_STATE_EXECUTED)
> +		cpu_relax();
>   
>   	return result;
>   

Re: [PATCH] powerpc/ps3: Use cpu_relax() in ps3_create_spu()

[Madhavan Srinivasan]

On Tue, 21 Jul 2026 01:11:53 +0200, Thorsten Blum wrote:
> Use cpu_relax() to wait for the execution status SPE_EX_STATE_EXECUTED.
> Drop the comments while at it.
> 
> 

Applied to powerpc/next.

[1/1] powerpc/ps3: Use cpu_relax() in ps3_create_spu()
      https://git.kernel.org/powerpc/c/6050e3196d97c679ea06c035dbb3c64264c01281

cheers

Re: [PATCH] powerpc/ps3: Use cpu_relax() in ps3_create_spu()

[Geert Uytterhoeven]

Hi Thorsten,

On Tue, 21 Jul 2026 at 01:12, Thorsten Blum <thorsten.blum@linux.dev> wrote:
> Use cpu_relax() to wait for the execution status SPE_EX_STATE_EXECUTED.
> Drop the comments while at it.
>
> Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>

Thanks for your patch!

> --- a/arch/powerpc/platforms/ps3/spu.c
> +++ b/arch/powerpc/platforms/ps3/spu.c
> @@ -13,6 +13,7 @@
>  #include <linux/export.h>
>  #include <linux/io.h>
>  #include <linux/mm.h>
> +#include <linux/processor.h>
>
>  #include <asm/spu.h>
>  #include <asm/spu_priv1.h>
> @@ -363,12 +364,9 @@ static int __init ps3_create_spu(struct spu *spu, void *data)
>         if (result)
>                 goto fail_enable;
>
> -       /* Make sure the spu is in SPE_EX_STATE_EXECUTED. */
> -
> -       /* need something better here!!! */
> -       while (in_be64(&spu_pdata(spu)->shadow->spe_execution_status)
> -               != SPE_EX_STATE_EXECUTED)
> -               (void)0;
> +       while (in_be64(&spu_pdata(spu)->shadow->spe_execution_status) !=
> +              SPE_EX_STATE_EXECUTED)
> +               cpu_relax();

I think we still need something better here, like proper timeout
handling using read_poll_timeout()?

>
>         return result;

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds