Re: [PATCH 1/2] x86: Remove the prefetch() specific implementation on x86_64

[Youling Tang]

On 30/05/2024 04:03, kernel test robot wrote:

> Hi Youling,
>
> kernel test robot noticed the following build errors:
>
> [auto build test ERROR on tip/master]
> [also build test ERROR on linus/master v6.10-rc1 next-20240529]
> [cannot apply to tip/auto-latest tip/x86/core bp/for-next]
> [If your patch is applied to the wrong git tree, kindly drop us a note.
> And when submitting patch, we suggest to use '--base' as documented in
> https://git-scm.com/docs/git-format-patch#_base_tree_information]
>
> url:    https://github.com/intel-lab-lkp/linux/commits/Youling-Tang/prefetch-Add-ARCH_HAS_PREFETCH-definition-when-the-architecture-is-not-defined/20240529-112345
> base:   tip/master
> patch link:    https://lore.kernel.org/r/20240529032059.899347-1-youling.tang%40linux.dev
> patch subject: [PATCH 1/2] x86: Remove the prefetch() specific implementation on x86_64
> config: x86_64-buildonly-randconfig-006-20240530 (https://download.01.org/0day-ci/archive/20240530/202405300328.eZmSYZrP-lkp@xxxxxxxxx/config)
> compiler: gcc-13 (Ubuntu 13.2.0-4ubuntu3) 13.2.0
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240530/202405300328.eZmSYZrP-lkp@xxxxxxxxx/reproduce)
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@xxxxxxxxx>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202405300328.eZmSYZrP-lkp@xxxxxxxxx/
>
> All errors (new ones prefixed by >>):
>
>     drivers/soc/fsl/dpio/dpio-service.c: In function 'dpaa2_io_store_next':
> > > drivers/soc/fsl/dpio/dpio-service.c:745:17: error: implicit declaration of function 'prefetch'; did you mean 'prefetchw'? [-Werror=implicit-function-declaration]
>       745 |                 prefetch(&s->vaddr[s->idx]);
>           |                 ^~~~~~~~
>           |                 prefetchw
>     cc1: some warnings being treated as errors
> --
>     drivers/soc/fsl/dpio/qbman-portal.c: In function 'qbman_swp_dqrr_next_direct':
> > > drivers/soc/fsl/dpio/qbman-portal.c:1213:17: error: implicit declaration of function 'prefetch'; did you mean 'prefetchw'? [-Werror=implicit-function-declaration]
>      1213 |                 prefetch(qbman_get_cmd(s,
>           |                 ^~~~~~~~
>           |                 prefetchw
>     cc1: some warnings being treated as errors
This problem is caused by not including the linux/prefetch.h file. There 
were
no build errors earlier because the definitions in processor.h were used
indirectly. (For architectures that do not implement prefetch, this build
error can occur without the patch).

We can fix it in the following way:
diff --git a/drivers/soc/fsl/dpio/dpio-service.c 
b/drivers/soc/fsl/dpio/dpio-service.c
index b811446e0fa5..a4692b9ad8d7 100644
--- a/drivers/soc/fsl/dpio/dpio-service.c
+++ b/drivers/soc/fsl/dpio/dpio-service.c
@@ -9,6 +9,7 @@
 #include <soc/fsl/dpaa2-io.h>
 #include <linux/init.h>
 #include <linux/module.h>
+#include <linux/prefetch.h>
 #include <linux/platform_device.h>
 #include <linux/interrupt.h>
 #include <linux/dma-mapping.h>
diff --git a/drivers/soc/fsl/dpio/qbman-portal.c 
b/drivers/soc/fsl/dpio/qbman-portal.c
index 0a3fb6c115f4..1c0bf04b101c 100644
--- a/drivers/soc/fsl/dpio/qbman-portal.c
+++ b/drivers/soc/fsl/dpio/qbman-portal.c
@@ -7,6 +7,7 @@

 #include <asm/cacheflush.h>
 #include <linux/io.h>
+#include <linux/prefetch.h>
 #include <linux/slab.h>

Thanks,
Youling.