mirror_zfs/config/kernel-fpu.m4
Tony Hutter 0c593296e9 Linux 5.0 compat: Disable vector instructions on 5.0+ kernels
The 5.0 kernel no longer exports the functions we need to do vector
(SSE/SSE2/SSE3/AVX...) instructions.  Disable vector-based checksum
algorithms when building against those kernels.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes #8259
2019-01-28 10:11:45 -08:00

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dnl #
dnl # Handle differences in kernel FPU code.
dnl #
dnl # Kernel
dnl # 5.0: All kernel fpu functions are GPL only, so we can't use them.
dnl # (nothing defined)
dnl #
dnl # 4.2: Use __kernel_fpu_{begin,end}()
dnl # HAVE_UNDERSCORE_KERNEL_FPU & KERNEL_EXPORTS_X86_FPU
dnl #
dnl # Pre-4.2: Use kernel_fpu_{begin,end}()
dnl # HAVE_KERNEL_FPU & KERNEL_EXPORTS_X86_FPU
dnl #
AC_DEFUN([ZFS_AC_KERNEL_FPU], [
AC_MSG_CHECKING([which kernel_fpu function to use])
ZFS_LINUX_TRY_COMPILE([
#include <asm/i387.h>
#include <asm/xcr.h>
],[
kernel_fpu_begin();
kernel_fpu_end();
],[
AC_MSG_RESULT(kernel_fpu_*)
AC_DEFINE(HAVE_KERNEL_FPU, 1, [kernel has kernel_fpu_* functions])
AC_DEFINE(KERNEL_EXPORTS_X86_FPU, 1, [kernel exports FPU functions])
],[
ZFS_LINUX_TRY_COMPILE([
#include <linux/kernel.h>
#include <asm/fpu/api.h>
],[
__kernel_fpu_begin();
__kernel_fpu_end();
],[
AC_MSG_RESULT(__kernel_fpu_*)
AC_DEFINE(HAVE_UNDERSCORE_KERNEL_FPU, 1, [kernel has __kernel_fpu_* functions])
AC_DEFINE(KERNEL_EXPORTS_X86_FPU, 1, [kernel exports FPU functions])
],[
AC_MSG_RESULT(not exported)
])
])
])