master FTBFS on a Linux/ppc64le system

[rincebrain]

System information

Type	Version/Name
Distribution Name	Debian
Distribution Version	bullseye
Kernel Version	5.15.41
Architecture	ppc64le
OpenZFS Version	b0657a59a

Describe the problem you're observing

master fails to build with:

/home/rich/zfs_vanilla/module/icp/algs/blake3/blake3_x86-64.c: In function ‘blake3_compress_in_place_sse2’:
/home/rich/zfs_vanilla/include/os/linux/kernel/linux/simd_powerpc.h:77:3: error: implicit declaration of function ‘enable_kernel_spe’; did you mean ‘enable_kernel_fp’? [-Werror=implicit-function-declaration]
   77 |   enable_kernel_spe();  \
      |   ^~~~~~~~~~~~~~~~~

It appears that needs to be guarded behind an #ifdef CONFIG_SPE or something to that effect.

Describe how to reproduce the problem

AFAICT, just try building it on a ppc64el system without CONFIG_SPE.

Include any warning/errors/backtraces from the system logs

N/A

[gyakovlev]

confirmed

This option is only useful if you have a processor that supports SPE (e500, otherwise known as 85xx series), but does not have any effect on a non-spe cpu (it does, however add code to the kernel).

The configuration item CONFIG_SPE:
    prompt: SPE Support
    type: bool
    depends on: CONFIG_E200 || CONFIG_E500

it's impossible to enable on ppc64le though.

so yeah, ifdef it is, testing a patch from @ryao right now.

diff --git a/include/os/linux/kernel/linux/simd_powerpc.h b/include/os/linux/kernel/linux/simd_powerpc.h
index 2a2f92bc4..f1de3ad01 100644
--- a/include/os/linux/kernel/linux/simd_powerpc.h
+++ b/include/os/linux/kernel/linux/simd_powerpc.h
@@ -69,6 +69,7 @@
 #define	kfpu_allowed()			1
 
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 5, 0)
+#ifdef CONFIG_SPE
 #define	kfpu_begin()				\
 	{					\
 		preempt_disable();		\
@@ -83,6 +84,20 @@
 		disable_kernel_altivec();	\
 		preempt_enable();		\
 	}
+#else /* CONFIG_SPE */
+#define	kfpu_begin()				\
+	{					\
+		preempt_disable();		\
+		enable_kernel_altivec();	\
+		enable_kernel_vsx();		\
+	}
+#define	kfpu_end()				\
+	{					\
+		disable_kernel_vsx();		\
+		disable_kernel_altivec();	\
+		preempt_enable();		\
+	}
+#endif
 #else
 /* seems that before 4.5 no-one bothered */
 #define	kfpu_begin()

[gyakovlev]

^ fix confirmed