1dnl #
2dnl # Handle differences in kernel FPU code.
3dnl #
4dnl # Kernel
5dnl # 5.19:	The asm/fpu/internal.h header was removed, it has been
6dnl #		effectively empty since the 5.16 kernel.
7dnl #
8dnl # 5.11:	kernel_fpu_begin() is an inlined function now, so don't check
9dnl #		for it inside the kernel symbols.
10dnl #
11dnl # 5.0:	Wrappers have been introduced to save/restore the FPU state.
12dnl #		This change was made to the 4.19.38 and 4.14.120 LTS kernels.
13dnl #		HAVE_KERNEL_FPU_INTERNAL
14dnl #
15dnl # 4.2:	Use __kernel_fpu_{begin,end}()
16dnl #		HAVE_UNDERSCORE_KERNEL_FPU & KERNEL_EXPORTS_X86_FPU
17dnl #
18dnl # Pre-4.2:	Use kernel_fpu_{begin,end}()
19dnl #		HAVE_KERNEL_FPU & KERNEL_EXPORTS_X86_FPU
20dnl #
21dnl # N.B. The header check is performed before all other checks since it
22dnl # depends on HAVE_KERNEL_FPU_API_HEADER being set in confdefs.h.
23dnl #
24AC_DEFUN([ZFS_AC_KERNEL_FPU_HEADER], [
25	AC_MSG_CHECKING([whether fpu headers are available])
26	ZFS_LINUX_TRY_COMPILE([
27		#include <linux/module.h>
28		#include <asm/fpu/api.h>
29	],[
30	],[
31		AC_DEFINE(HAVE_KERNEL_FPU_API_HEADER, 1,
32		    [kernel has asm/fpu/api.h])
33
34		ZFS_LINUX_TRY_COMPILE([
35			#include <linux/module.h>
36			#include <asm/fpu/internal.h>
37		],[
38		],[
39			AC_DEFINE(HAVE_KERNEL_FPU_INTERNAL_HEADER, 1,
40			    [kernel has asm/fpu/internal.h])
41			AC_MSG_RESULT([asm/fpu/api.h asm/fpu/internal.h])
42		],[
43			AC_MSG_RESULT([asm/fpu/api.h])
44		])
45	],[
46		AC_MSG_RESULT([i387.h])
47	])
48
49])
50
51AC_DEFUN([ZFS_AC_KERNEL_SRC_FPU], [
52	ZFS_LINUX_TEST_SRC([kernel_fpu], [
53		#include <linux/types.h>
54		#ifdef HAVE_KERNEL_FPU_API_HEADER
55		#include <asm/fpu/api.h>
56		#ifdef HAVE_KERNEL_FPU_INTERNAL_HEADER
57		#include <asm/fpu/internal.h>
58		#endif
59		#else
60		#include <asm/i387.h>
61		#endif
62	], [
63		kernel_fpu_begin();
64		kernel_fpu_end();
65	], [], [ZFS_META_LICENSE])
66
67	ZFS_LINUX_TEST_SRC([__kernel_fpu], [
68		#include <linux/types.h>
69		#ifdef HAVE_KERNEL_FPU_API_HEADER
70		#include <asm/fpu/api.h>
71		#ifdef HAVE_KERNEL_FPU_INTERNAL_HEADER
72		#include <asm/fpu/internal.h>
73		#endif
74		#else
75		#include <asm/i387.h>
76		#endif
77	], [
78		__kernel_fpu_begin();
79		__kernel_fpu_end();
80	], [], [ZFS_META_LICENSE])
81
82	ZFS_LINUX_TEST_SRC([kernel_neon], [
83		#include <asm/neon.h>
84	], [
85		kernel_neon_begin();
86		kernel_neon_end();
87	], [], [ZFS_META_LICENSE])
88])
89
90AC_DEFUN([ZFS_AC_KERNEL_FPU], [
91	dnl #
92	dnl # Legacy kernel
93	dnl #
94	AC_MSG_CHECKING([whether kernel fpu is available])
95	ZFS_LINUX_TEST_RESULT([kernel_fpu_license], [
96		AC_MSG_RESULT(kernel_fpu_*)
97		AC_DEFINE(HAVE_KERNEL_FPU, 1,
98		    [kernel has kernel_fpu_* functions])
99		AC_DEFINE(KERNEL_EXPORTS_X86_FPU, 1,
100		    [kernel exports FPU functions])
101	],[
102		dnl #
103		dnl # Linux 4.2 kernel
104		dnl #
105		ZFS_LINUX_TEST_RESULT_SYMBOL([__kernel_fpu_license],
106		    [__kernel_fpu_begin],
107		    [arch/x86/kernel/fpu/core.c arch/x86/kernel/i387.c], [
108			AC_MSG_RESULT(__kernel_fpu_*)
109			AC_DEFINE(HAVE_UNDERSCORE_KERNEL_FPU, 1,
110			    [kernel has __kernel_fpu_* functions])
111			AC_DEFINE(KERNEL_EXPORTS_X86_FPU, 1,
112			    [kernel exports FPU functions])
113		],[
114			dnl #
115			dnl # ARM neon symbols (only on arm and arm64)
116			dnl # could be GPL-only on arm64 after Linux 6.2
117			dnl #
118			ZFS_LINUX_TEST_RESULT([kernel_neon_license],[
119				AC_MSG_RESULT(kernel_neon_*)
120				AC_DEFINE(HAVE_KERNEL_NEON, 1,
121				    [kernel has kernel_neon_* functions])
122			],[
123				# catch-all
124				AC_MSG_RESULT(internal)
125				AC_DEFINE(HAVE_KERNEL_FPU_INTERNAL, 1,
126				    [kernel fpu internal])
127			])
128		])
129	])
130])
131