xref: /freebsd/sys/contrib/openzfs/config/kernel.m4 (revision 5ca8e32633c4ffbbcd6762e5888b6a4ba0708c6c) 
1dnl #
2dnl # Default ZFS kernel configuration
3dnl #
4AC_DEFUN([ZFS_AC_CONFIG_KERNEL], [
5	AM_COND_IF([BUILD_LINUX], [
6		dnl # Setup the kernel build environment.
7		ZFS_AC_KERNEL
8		ZFS_AC_QAT
9
10		dnl # Sanity checks for module building and CONFIG_* defines
11		ZFS_AC_KERNEL_CONFIG_DEFINED
12		ZFS_AC_MODULE_SYMVERS
13
14		dnl # Sequential ZFS_LINUX_TRY_COMPILE tests
15		ZFS_AC_KERNEL_FPU_HEADER
16		ZFS_AC_KERNEL_OBJTOOL_HEADER
17		ZFS_AC_KERNEL_WAIT_QUEUE_ENTRY_T
18		ZFS_AC_KERNEL_MISC_MINOR
19		ZFS_AC_KERNEL_DECLARE_EVENT_CLASS
20
21		dnl # Parallel ZFS_LINUX_TEST_SRC / ZFS_LINUX_TEST_RESULT tests
22		ZFS_AC_KERNEL_TEST_SRC
23		ZFS_AC_KERNEL_TEST_RESULT
24
25		AS_IF([test "$LINUX_OBJ" != "$LINUX"], [
26			KERNEL_MAKE="$KERNEL_MAKE O=$LINUX_OBJ"
27		])
28
29		AC_SUBST(KERNEL_MAKE)
30	])
31])
32
33dnl #
34dnl # Generate and compile all of the kernel API test cases to determine
35dnl # which interfaces are available.  By invoking the kernel build system
36dnl # only once the compilation can be done in parallel significantly
37dnl # speeding up the process.
38dnl #
39AC_DEFUN([ZFS_AC_KERNEL_TEST_SRC], [
40	ZFS_AC_KERNEL_SRC_OBJTOOL
41	ZFS_AC_KERNEL_SRC_GLOBAL_PAGE_STATE
42	ZFS_AC_KERNEL_SRC_ACCESS_OK_TYPE
43	ZFS_AC_KERNEL_SRC_PDE_DATA
44	ZFS_AC_KERNEL_SRC_FALLOCATE
45	ZFS_AC_KERNEL_SRC_FADVISE
46	ZFS_AC_KERNEL_SRC_GENERIC_FADVISE
47	ZFS_AC_KERNEL_SRC_2ARGS_ZLIB_DEFLATE_WORKSPACESIZE
48	ZFS_AC_KERNEL_SRC_RWSEM
49	ZFS_AC_KERNEL_SRC_SCHED
50	ZFS_AC_KERNEL_SRC_USLEEP_RANGE
51	ZFS_AC_KERNEL_SRC_KMEM_CACHE
52	ZFS_AC_KERNEL_SRC_KVMALLOC
53	ZFS_AC_KERNEL_SRC_VMALLOC_PAGE_KERNEL
54	ZFS_AC_KERNEL_SRC_WAIT
55	ZFS_AC_KERNEL_SRC_INODE_TIMES
56	ZFS_AC_KERNEL_SRC_INODE_LOCK
57	ZFS_AC_KERNEL_SRC_GROUP_INFO_GID
58	ZFS_AC_KERNEL_SRC_RW
59	ZFS_AC_KERNEL_SRC_TIMER_SETUP
60	ZFS_AC_KERNEL_SRC_SUPER_USER_NS
61	ZFS_AC_KERNEL_SRC_PROC_OPERATIONS
62	ZFS_AC_KERNEL_SRC_BLOCK_DEVICE_OPERATIONS
63	ZFS_AC_KERNEL_SRC_BIO
64	ZFS_AC_KERNEL_SRC_BLKDEV
65	ZFS_AC_KERNEL_SRC_BLK_QUEUE
66	ZFS_AC_KERNEL_SRC_GENHD_FLAGS
67	ZFS_AC_KERNEL_SRC_REVALIDATE_DISK
68	ZFS_AC_KERNEL_SRC_GET_DISK_RO
69	ZFS_AC_KERNEL_SRC_GENERIC_READLINK_GLOBAL
70	ZFS_AC_KERNEL_SRC_DISCARD_GRANULARITY
71	ZFS_AC_KERNEL_SRC_INODE_OWNER_OR_CAPABLE
72	ZFS_AC_KERNEL_SRC_XATTR
73	ZFS_AC_KERNEL_SRC_ACL
74	ZFS_AC_KERNEL_SRC_INODE_SETATTR
75	ZFS_AC_KERNEL_SRC_INODE_GETATTR
76	ZFS_AC_KERNEL_SRC_INODE_SET_FLAGS
77	ZFS_AC_KERNEL_SRC_INODE_SET_IVERSION
78	ZFS_AC_KERNEL_SRC_SHOW_OPTIONS
79	ZFS_AC_KERNEL_SRC_FILE_INODE
80	ZFS_AC_KERNEL_SRC_FILE_DENTRY
81	ZFS_AC_KERNEL_SRC_FSYNC
82	ZFS_AC_KERNEL_SRC_AIO_FSYNC
83	ZFS_AC_KERNEL_SRC_EVICT_INODE
84	ZFS_AC_KERNEL_SRC_DIRTY_INODE
85	ZFS_AC_KERNEL_SRC_SHRINKER
86	ZFS_AC_KERNEL_SRC_MKDIR
87	ZFS_AC_KERNEL_SRC_LOOKUP_FLAGS
88	ZFS_AC_KERNEL_SRC_CREATE
89	ZFS_AC_KERNEL_SRC_PERMISSION
90	ZFS_AC_KERNEL_SRC_GET_LINK
91	ZFS_AC_KERNEL_SRC_PUT_LINK
92	ZFS_AC_KERNEL_SRC_TMPFILE
93	ZFS_AC_KERNEL_SRC_AUTOMOUNT
94	ZFS_AC_KERNEL_SRC_ENCODE_FH_WITH_INODE
95	ZFS_AC_KERNEL_SRC_COMMIT_METADATA
96	ZFS_AC_KERNEL_SRC_CLEAR_INODE
97	ZFS_AC_KERNEL_SRC_SETATTR_PREPARE
98	ZFS_AC_KERNEL_SRC_INSERT_INODE_LOCKED
99	ZFS_AC_KERNEL_SRC_DENTRY
100	ZFS_AC_KERNEL_SRC_DENTRY_ALIAS_D_U
101	ZFS_AC_KERNEL_SRC_TRUNCATE_SETSIZE
102	ZFS_AC_KERNEL_SRC_SECURITY_INODE
103	ZFS_AC_KERNEL_SRC_FST_MOUNT
104	ZFS_AC_KERNEL_SRC_BDI
105	ZFS_AC_KERNEL_SRC_SET_NLINK
106	ZFS_AC_KERNEL_SRC_SGET
107	ZFS_AC_KERNEL_SRC_LSEEK_EXECUTE
108	ZFS_AC_KERNEL_SRC_VFS_FILEMAP_DIRTY_FOLIO
109	ZFS_AC_KERNEL_SRC_VFS_READ_FOLIO
110	ZFS_AC_KERNEL_SRC_VFS_GETATTR
111	ZFS_AC_KERNEL_SRC_VFS_FSYNC_2ARGS
112	ZFS_AC_KERNEL_SRC_VFS_ITERATE
113	ZFS_AC_KERNEL_SRC_VFS_DIRECT_IO
114	ZFS_AC_KERNEL_SRC_VFS_READPAGES
115	ZFS_AC_KERNEL_SRC_VFS_SET_PAGE_DIRTY_NOBUFFERS
116	ZFS_AC_KERNEL_SRC_VFS_RW_ITERATE
117	ZFS_AC_KERNEL_SRC_VFS_GENERIC_WRITE_CHECKS
118	ZFS_AC_KERNEL_SRC_VFS_IOV_ITER
119	ZFS_AC_KERNEL_SRC_VFS_COPY_FILE_RANGE
120	ZFS_AC_KERNEL_SRC_VFS_GENERIC_COPY_FILE_RANGE
121	ZFS_AC_KERNEL_SRC_VFS_REMAP_FILE_RANGE
122	ZFS_AC_KERNEL_SRC_VFS_CLONE_FILE_RANGE
123	ZFS_AC_KERNEL_SRC_VFS_DEDUPE_FILE_RANGE
124	ZFS_AC_KERNEL_SRC_VFS_FILE_OPERATIONS_EXTEND
125	ZFS_AC_KERNEL_SRC_KMAP_ATOMIC_ARGS
126	ZFS_AC_KERNEL_SRC_FOLLOW_DOWN_ONE
127	ZFS_AC_KERNEL_SRC_MAKE_REQUEST_FN
128	ZFS_AC_KERNEL_SRC_GENERIC_IO_ACCT
129	ZFS_AC_KERNEL_SRC_FPU
130	ZFS_AC_KERNEL_SRC_FMODE_T
131	ZFS_AC_KERNEL_SRC_KUIDGID_T
132	ZFS_AC_KERNEL_SRC_KUID_HELPERS
133	ZFS_AC_KERNEL_SRC_RENAME
134	ZFS_AC_KERNEL_SRC_CURRENT_TIME
135	ZFS_AC_KERNEL_SRC_USERNS_CAPABILITIES
136	ZFS_AC_KERNEL_SRC_IN_COMPAT_SYSCALL
137	ZFS_AC_KERNEL_SRC_KTIME
138	ZFS_AC_KERNEL_SRC_TOTALRAM_PAGES_FUNC
139	ZFS_AC_KERNEL_SRC_TOTALHIGH_PAGES
140	ZFS_AC_KERNEL_SRC_KSTRTOUL
141	ZFS_AC_KERNEL_SRC_PERCPU
142	ZFS_AC_KERNEL_SRC_CPU_HOTPLUG
143	ZFS_AC_KERNEL_SRC_GENERIC_FILLATTR
144	ZFS_AC_KERNEL_SRC_MKNOD
145	ZFS_AC_KERNEL_SRC_SYMLINK
146	ZFS_AC_KERNEL_SRC_BIO_MAX_SEGS
147	ZFS_AC_KERNEL_SRC_SIGNAL_STOP
148	ZFS_AC_KERNEL_SRC_SIGINFO
149	ZFS_AC_KERNEL_SRC_SYSFS
150	ZFS_AC_KERNEL_SRC_SET_SPECIAL_STATE
151	ZFS_AC_KERNEL_SRC_STANDALONE_LINUX_STDARG
152	ZFS_AC_KERNEL_SRC_STRLCPY
153	ZFS_AC_KERNEL_SRC_STRSCPY
154	ZFS_AC_KERNEL_SRC_PAGEMAP_FOLIO_WAIT_BIT
155	ZFS_AC_KERNEL_SRC_ADD_DISK
156	ZFS_AC_KERNEL_SRC_KTHREAD
157	ZFS_AC_KERNEL_SRC_ZERO_PAGE
158	ZFS_AC_KERNEL_SRC___COPY_FROM_USER_INATOMIC
159	ZFS_AC_KERNEL_SRC_USER_NS_COMMON_INUM
160	ZFS_AC_KERNEL_SRC_IDMAP_MNT_API
161	ZFS_AC_KERNEL_SRC_IDMAP_NO_USERNS
162	ZFS_AC_KERNEL_SRC_IATTR_VFSID
163	ZFS_AC_KERNEL_SRC_FILEMAP
164	ZFS_AC_KERNEL_SRC_WRITEPAGE_T
165	ZFS_AC_KERNEL_SRC_RECLAIMED
166	ZFS_AC_KERNEL_SRC_REGISTER_SYSCTL_TABLE
167	ZFS_AC_KERNEL_SRC_COPY_SPLICE_READ
168	ZFS_AC_KERNEL_SRC_SYNC_BDEV
169	case "$host_cpu" in
170		powerpc*)
171			ZFS_AC_KERNEL_SRC_CPU_HAS_FEATURE
172			ZFS_AC_KERNEL_SRC_FLUSH_DCACHE_PAGE
173			;;
174		riscv*)
175			ZFS_AC_KERNEL_SRC_FLUSH_DCACHE_PAGE
176			;;
177	esac
178
179	AC_MSG_CHECKING([for available kernel interfaces])
180	ZFS_LINUX_TEST_COMPILE_ALL([kabi])
181	AC_MSG_RESULT([done])
182])
183
184dnl #
185dnl # Check results of kernel interface tests.
186dnl #
187AC_DEFUN([ZFS_AC_KERNEL_TEST_RESULT], [
188	ZFS_AC_KERNEL_ACCESS_OK_TYPE
189	ZFS_AC_KERNEL_GLOBAL_PAGE_STATE
190	ZFS_AC_KERNEL_OBJTOOL
191	ZFS_AC_KERNEL_PDE_DATA
192	ZFS_AC_KERNEL_FALLOCATE
193	ZFS_AC_KERNEL_FADVISE
194	ZFS_AC_KERNEL_GENERIC_FADVISE
195	ZFS_AC_KERNEL_2ARGS_ZLIB_DEFLATE_WORKSPACESIZE
196	ZFS_AC_KERNEL_RWSEM
197	ZFS_AC_KERNEL_SCHED
198	ZFS_AC_KERNEL_USLEEP_RANGE
199	ZFS_AC_KERNEL_KMEM_CACHE
200	ZFS_AC_KERNEL_KVMALLOC
201	ZFS_AC_KERNEL_VMALLOC_PAGE_KERNEL
202	ZFS_AC_KERNEL_WAIT
203	ZFS_AC_KERNEL_INODE_TIMES
204	ZFS_AC_KERNEL_INODE_LOCK
205	ZFS_AC_KERNEL_GROUP_INFO_GID
206	ZFS_AC_KERNEL_RW
207	ZFS_AC_KERNEL_TIMER_SETUP
208	ZFS_AC_KERNEL_SUPER_USER_NS
209	ZFS_AC_KERNEL_PROC_OPERATIONS
210	ZFS_AC_KERNEL_BLOCK_DEVICE_OPERATIONS
211	ZFS_AC_KERNEL_BIO
212	ZFS_AC_KERNEL_BLKDEV
213	ZFS_AC_KERNEL_BLK_QUEUE
214	ZFS_AC_KERNEL_GENHD_FLAGS
215	ZFS_AC_KERNEL_REVALIDATE_DISK
216	ZFS_AC_KERNEL_GET_DISK_RO
217	ZFS_AC_KERNEL_GENERIC_READLINK_GLOBAL
218	ZFS_AC_KERNEL_DISCARD_GRANULARITY
219	ZFS_AC_KERNEL_INODE_OWNER_OR_CAPABLE
220	ZFS_AC_KERNEL_XATTR
221	ZFS_AC_KERNEL_ACL
222	ZFS_AC_KERNEL_INODE_SETATTR
223	ZFS_AC_KERNEL_INODE_GETATTR
224	ZFS_AC_KERNEL_INODE_SET_FLAGS
225	ZFS_AC_KERNEL_INODE_SET_IVERSION
226	ZFS_AC_KERNEL_SHOW_OPTIONS
227	ZFS_AC_KERNEL_FILE_INODE
228	ZFS_AC_KERNEL_FILE_DENTRY
229	ZFS_AC_KERNEL_FSYNC
230	ZFS_AC_KERNEL_AIO_FSYNC
231	ZFS_AC_KERNEL_EVICT_INODE
232	ZFS_AC_KERNEL_DIRTY_INODE
233	ZFS_AC_KERNEL_SHRINKER
234	ZFS_AC_KERNEL_MKDIR
235	ZFS_AC_KERNEL_LOOKUP_FLAGS
236	ZFS_AC_KERNEL_CREATE
237	ZFS_AC_KERNEL_PERMISSION
238	ZFS_AC_KERNEL_GET_LINK
239	ZFS_AC_KERNEL_PUT_LINK
240	ZFS_AC_KERNEL_TMPFILE
241	ZFS_AC_KERNEL_AUTOMOUNT
242	ZFS_AC_KERNEL_ENCODE_FH_WITH_INODE
243	ZFS_AC_KERNEL_COMMIT_METADATA
244	ZFS_AC_KERNEL_CLEAR_INODE
245	ZFS_AC_KERNEL_SETATTR_PREPARE
246	ZFS_AC_KERNEL_INSERT_INODE_LOCKED
247	ZFS_AC_KERNEL_DENTRY
248	ZFS_AC_KERNEL_DENTRY_ALIAS_D_U
249	ZFS_AC_KERNEL_TRUNCATE_SETSIZE
250	ZFS_AC_KERNEL_SECURITY_INODE
251	ZFS_AC_KERNEL_FST_MOUNT
252	ZFS_AC_KERNEL_BDI
253	ZFS_AC_KERNEL_SET_NLINK
254	ZFS_AC_KERNEL_SGET
255	ZFS_AC_KERNEL_LSEEK_EXECUTE
256	ZFS_AC_KERNEL_VFS_FILEMAP_DIRTY_FOLIO
257	ZFS_AC_KERNEL_VFS_READ_FOLIO
258	ZFS_AC_KERNEL_VFS_GETATTR
259	ZFS_AC_KERNEL_VFS_FSYNC_2ARGS
260	ZFS_AC_KERNEL_VFS_ITERATE
261	ZFS_AC_KERNEL_VFS_DIRECT_IO
262	ZFS_AC_KERNEL_VFS_READPAGES
263	ZFS_AC_KERNEL_VFS_SET_PAGE_DIRTY_NOBUFFERS
264	ZFS_AC_KERNEL_VFS_RW_ITERATE
265	ZFS_AC_KERNEL_VFS_GENERIC_WRITE_CHECKS
266	ZFS_AC_KERNEL_VFS_IOV_ITER
267	ZFS_AC_KERNEL_VFS_COPY_FILE_RANGE
268	ZFS_AC_KERNEL_VFS_GENERIC_COPY_FILE_RANGE
269	ZFS_AC_KERNEL_VFS_REMAP_FILE_RANGE
270	ZFS_AC_KERNEL_VFS_CLONE_FILE_RANGE
271	ZFS_AC_KERNEL_VFS_DEDUPE_FILE_RANGE
272	ZFS_AC_KERNEL_VFS_FILE_OPERATIONS_EXTEND
273	ZFS_AC_KERNEL_KMAP_ATOMIC_ARGS
274	ZFS_AC_KERNEL_FOLLOW_DOWN_ONE
275	ZFS_AC_KERNEL_MAKE_REQUEST_FN
276	ZFS_AC_KERNEL_GENERIC_IO_ACCT
277	ZFS_AC_KERNEL_FPU
278	ZFS_AC_KERNEL_FMODE_T
279	ZFS_AC_KERNEL_KUIDGID_T
280	ZFS_AC_KERNEL_KUID_HELPERS
281	ZFS_AC_KERNEL_RENAME
282	ZFS_AC_KERNEL_CURRENT_TIME
283	ZFS_AC_KERNEL_USERNS_CAPABILITIES
284	ZFS_AC_KERNEL_IN_COMPAT_SYSCALL
285	ZFS_AC_KERNEL_KTIME
286	ZFS_AC_KERNEL_TOTALRAM_PAGES_FUNC
287	ZFS_AC_KERNEL_TOTALHIGH_PAGES
288	ZFS_AC_KERNEL_KSTRTOUL
289	ZFS_AC_KERNEL_PERCPU
290	ZFS_AC_KERNEL_CPU_HOTPLUG
291	ZFS_AC_KERNEL_GENERIC_FILLATTR
292	ZFS_AC_KERNEL_MKNOD
293	ZFS_AC_KERNEL_SYMLINK
294	ZFS_AC_KERNEL_BIO_MAX_SEGS
295	ZFS_AC_KERNEL_SIGNAL_STOP
296	ZFS_AC_KERNEL_SIGINFO
297	ZFS_AC_KERNEL_SYSFS
298	ZFS_AC_KERNEL_SET_SPECIAL_STATE
299	ZFS_AC_KERNEL_STANDALONE_LINUX_STDARG
300	ZFS_AC_KERNEL_STRLCPY
301	ZFS_AC_KERNEL_STRSCPY
302	ZFS_AC_KERNEL_PAGEMAP_FOLIO_WAIT_BIT
303	ZFS_AC_KERNEL_ADD_DISK
304	ZFS_AC_KERNEL_KTHREAD
305	ZFS_AC_KERNEL_ZERO_PAGE
306	ZFS_AC_KERNEL___COPY_FROM_USER_INATOMIC
307	ZFS_AC_KERNEL_USER_NS_COMMON_INUM
308	ZFS_AC_KERNEL_IDMAP_MNT_API
309	ZFS_AC_KERNEL_IDMAP_NO_USERNS
310	ZFS_AC_KERNEL_IATTR_VFSID
311	ZFS_AC_KERNEL_FILEMAP
312	ZFS_AC_KERNEL_WRITEPAGE_T
313	ZFS_AC_KERNEL_RECLAIMED
314	ZFS_AC_KERNEL_REGISTER_SYSCTL_TABLE
315	ZFS_AC_KERNEL_COPY_SPLICE_READ
316	ZFS_AC_KERNEL_SYNC_BDEV
317	case "$host_cpu" in
318		powerpc*)
319			ZFS_AC_KERNEL_CPU_HAS_FEATURE
320			ZFS_AC_KERNEL_FLUSH_DCACHE_PAGE
321			;;
322		riscv*)
323			ZFS_AC_KERNEL_FLUSH_DCACHE_PAGE
324			;;
325	esac
326])
327
328dnl #
329dnl # Detect name used for Module.symvers file in kernel
330dnl #
331AC_DEFUN([ZFS_AC_MODULE_SYMVERS], [
332	modpost=$LINUX/scripts/Makefile.modpost
333	AC_MSG_CHECKING([kernel file name for module symbols])
334	AS_IF([test "x$enable_linux_builtin" != xyes -a -f "$modpost"], [
335		AS_IF([grep -q Modules.symvers $modpost], [
336			LINUX_SYMBOLS=Modules.symvers
337		], [
338			LINUX_SYMBOLS=Module.symvers
339		])
340
341		AS_IF([test ! -f "$LINUX_OBJ/$LINUX_SYMBOLS"], [
342			AC_MSG_ERROR([
343	*** Please make sure the kernel devel package for your distribution
344	*** is installed.  If you are building with a custom kernel, make sure
345	*** the kernel is configured, built, and the '--with-linux=PATH'
346	*** configure option refers to the location of the kernel source.
347			])
348		])
349	], [
350		LINUX_SYMBOLS=NONE
351	])
352	AC_MSG_RESULT($LINUX_SYMBOLS)
353	AC_SUBST(LINUX_SYMBOLS)
354])
355
356dnl #
357dnl # Detect the kernel to be built against
358dnl #
359dnl # Most modern Linux distributions have separate locations for bare
360dnl # source (source) and prebuilt (build) files. Additionally, there are
361dnl # `source` and `build` symlinks in `/lib/modules/$(KERNEL_VERSION)`
362dnl # pointing to them. The directory search order is now:
363dnl #
364dnl # - `configure` command line values if both `--with-linux` and
365dnl #   `--with-linux-obj` were defined
366dnl #
367dnl # - If only `--with-linux` was defined, `--with-linux-obj` is assumed
368dnl #   to have the same value as `--with-linux`
369dnl #
370dnl # - If neither `--with-linux` nor `--with-linux-obj` were defined
371dnl #   autodetection is used:
372dnl #
373dnl #   - `/lib/modules/$(uname -r)/{source,build}` respectively, if exist.
374dnl #
375dnl #   - If only `/lib/modules/$(uname -r)/build` exists, it is assumed
376dnl #     to be both source and build directory.
377dnl #
378dnl #   - The first directory in `/lib/modules` with the highest version
379dnl #     number according to `sort -V` which contains both `source` and
380dnl #     `build` symlinks/directories. If module directory contains only
381dnl #     `build` component, it is assumed to be both source and build
382dnl #     directory.
383dnl #
384dnl #   - Last resort: the first directory matching `/usr/src/kernels/*`
385dnl #     and `/usr/src/linux-*` with the highest version number according
386dnl #     to `sort -V` is assumed to be both source and build directory.
387dnl #
388AC_DEFUN([ZFS_AC_KERNEL], [
389	AC_ARG_WITH([linux],
390		AS_HELP_STRING([--with-linux=PATH],
391		[Path to kernel source]),
392		[kernelsrc="$withval"])
393
394	AC_ARG_WITH(linux-obj,
395		AS_HELP_STRING([--with-linux-obj=PATH],
396		[Path to kernel build objects]),
397		[kernelbuild="$withval"])
398
399	AC_MSG_CHECKING([kernel source and build directories])
400	AS_IF([test -n "$kernelsrc" && test -z "$kernelbuild"], [
401		kernelbuild="$kernelsrc"
402	], [test -z "$kernelsrc"], [
403		AS_IF([test -e "/lib/modules/$(uname -r)/source" && \
404		       test -e "/lib/modules/$(uname -r)/build"], [
405			src="/lib/modules/$(uname -r)/source"
406			build="/lib/modules/$(uname -r)/build"
407		], [test -e "/lib/modules/$(uname -r)/build"], [
408			build="/lib/modules/$(uname -r)/build"
409			src="$build"
410		], [
411			src=
412
413			for d in $(ls -1d /lib/modules/* 2>/dev/null | sort -Vr); do
414				if test -e "$d/source" && test -e "$d/build"; then
415					src="$d/source"
416					build="$d/build"
417					break
418				fi
419
420				if test -e "$d/build"; then
421					src="$d/build"
422					build="$d/build"
423					break
424				fi
425			done
426
427			# the least reliable method
428			if test -z "$src"; then
429				src=$(ls -1d /usr/src/kernels/* /usr/src/linux-* \
430				      2>/dev/null | grep -v obj | sort -Vr | head -1)
431				build="$src"
432			fi
433		])
434
435		AS_IF([test -n "$src" && test -e "$src"], [
436			kernelsrc=$(readlink -e "$src")
437		], [
438			kernelsrc="[Not found]"
439		])
440		AS_IF([test -n "$build" && test -e "$build"], [
441			kernelbuild=$(readlink -e "$build")
442		], [
443			kernelbuild="[Not found]"
444		])
445	], [
446		AS_IF([test "$kernelsrc" = "NONE"], [
447			kernsrcver=NONE
448		])
449		withlinux=yes
450	])
451
452	AC_MSG_RESULT([done])
453	AC_MSG_CHECKING([kernel source directory])
454	AC_MSG_RESULT([$kernelsrc])
455	AC_MSG_CHECKING([kernel build directory])
456	AC_MSG_RESULT([$kernelbuild])
457	AS_IF([test ! -d "$kernelsrc" || test ! -d "$kernelbuild"], [
458		AC_MSG_ERROR([
459	*** Please make sure the kernel devel package for your distribution
460	*** is installed and then try again.  If that fails, you can specify the
461	*** location of the kernel source and build with the '--with-linux=PATH' and
462	*** '--with-linux-obj=PATH' options respectively.])
463	])
464
465	AC_MSG_CHECKING([kernel source version])
466	utsrelease1=$kernelbuild/include/linux/version.h
467	utsrelease2=$kernelbuild/include/linux/utsrelease.h
468	utsrelease3=$kernelbuild/include/generated/utsrelease.h
469	AS_IF([test -r $utsrelease1 && grep -qF UTS_RELEASE $utsrelease1], [
470		utsrelease=$utsrelease1
471	], [test -r $utsrelease2 && grep -qF UTS_RELEASE $utsrelease2], [
472		utsrelease=$utsrelease2
473	], [test -r $utsrelease3 && grep -qF UTS_RELEASE $utsrelease3], [
474		utsrelease=$utsrelease3
475	])
476
477	AS_IF([test -n "$utsrelease"], [
478		kernsrcver=$($AWK '/UTS_RELEASE/ { gsub(/"/, "", $[3]); print $[3] }' $utsrelease)
479		AS_IF([test -z "$kernsrcver"], [
480			AC_MSG_RESULT([Not found])
481			AC_MSG_ERROR([
482	*** Cannot determine kernel version.
483			])
484		])
485	], [
486		AC_MSG_RESULT([Not found])
487		if test "x$enable_linux_builtin" != xyes; then
488			AC_MSG_ERROR([
489	*** Cannot find UTS_RELEASE definition.
490			])
491		else
492			AC_MSG_ERROR([
493	*** Cannot find UTS_RELEASE definition.
494	*** Please run 'make prepare' inside the kernel source tree.])
495		fi
496	])
497
498	AC_MSG_RESULT([$kernsrcver])
499
500	AS_VERSION_COMPARE([$kernsrcver], [$ZFS_META_KVER_MIN], [
501		 AC_MSG_ERROR([
502	*** Cannot build against kernel version $kernsrcver.
503	*** The minimum supported kernel version is $ZFS_META_KVER_MIN.
504		])
505	])
506
507	LINUX=${kernelsrc}
508	LINUX_OBJ=${kernelbuild}
509	LINUX_VERSION=${kernsrcver}
510
511	AC_SUBST(LINUX)
512	AC_SUBST(LINUX_OBJ)
513	AC_SUBST(LINUX_VERSION)
514])
515
516dnl #
517dnl # Detect the QAT module to be built against, QAT provides hardware
518dnl # acceleration for data compression:
519dnl #
520dnl # https://01.org/intel-quickassist-technology
521dnl #
522dnl # 1) Download and install QAT driver from the above link
523dnl # 2) Start QAT driver in your system:
524dnl # 	 service qat_service start
525dnl # 3) Enable QAT in ZFS, e.g.:
526dnl # 	 ./configure --with-qat=<qat-driver-path>/QAT1.6
527dnl # 	 make
528dnl # 4) Set GZIP compression in ZFS dataset:
529dnl # 	 zfs set compression = gzip <dataset>
530dnl #
531dnl # Then the data written to this ZFS pool is compressed by QAT accelerator
532dnl # automatically, and de-compressed by QAT when read from the pool.
533dnl #
534dnl # 1) Get QAT hardware statistics with:
535dnl #	 cat /proc/icp_dh895xcc_dev/qat
536dnl # 2) To disable QAT:
537dnl # 	 insmod zfs.ko zfs_qat_disable=1
538dnl #
539AC_DEFUN([ZFS_AC_QAT], [
540	AC_ARG_WITH([qat],
541		AS_HELP_STRING([--with-qat=PATH],
542		[Path to qat source]),
543		AS_IF([test "$withval" = "yes"],
544			AC_MSG_ERROR([--with-qat=PATH requires a PATH]),
545			[qatsrc="$withval"]))
546
547	AC_ARG_WITH([qat-obj],
548		AS_HELP_STRING([--with-qat-obj=PATH],
549		[Path to qat build objects]),
550		[qatbuild="$withval"])
551
552	AS_IF([test ! -z "${qatsrc}"], [
553		AC_MSG_CHECKING([qat source directory])
554		AC_MSG_RESULT([$qatsrc])
555		QAT_SRC="${qatsrc}/quickassist"
556		AS_IF([ test ! -e "$QAT_SRC/include/cpa.h"], [
557			AC_MSG_ERROR([
558	*** Please make sure the qat driver package is installed
559	*** and specify the location of the qat source with the
560	*** '--with-qat=PATH' option then try again. Failed to
561	*** find cpa.h in:
562	${QAT_SRC}/include])
563		])
564	])
565
566	AS_IF([test ! -z "${qatsrc}"], [
567		AC_MSG_CHECKING([qat build directory])
568		AS_IF([test -z "$qatbuild"], [
569			qatbuild="${qatsrc}/build"
570		])
571
572		AC_MSG_RESULT([$qatbuild])
573		QAT_OBJ=${qatbuild}
574		AS_IF([ ! test -e "$QAT_OBJ/icp_qa_al.ko" && ! test -e "$QAT_OBJ/qat_api.ko"], [
575			AC_MSG_ERROR([
576	*** Please make sure the qat driver is installed then try again.
577	*** Failed to find icp_qa_al.ko or qat_api.ko in:
578	$QAT_OBJ])
579		])
580
581		AC_SUBST(QAT_SRC)
582		AC_SUBST(QAT_OBJ)
583
584		AC_DEFINE(HAVE_QAT, 1,
585		[qat is enabled and existed])
586	])
587
588	dnl #
589	dnl # Detect the name used for the QAT Module.symvers file.
590	dnl #
591	AS_IF([test ! -z "${qatsrc}"], [
592		AC_MSG_CHECKING([qat file for module symbols])
593		QAT_SYMBOLS=$QAT_SRC/lookaside/access_layer/src/Module.symvers
594
595		AS_IF([test -r $QAT_SYMBOLS], [
596			AC_MSG_RESULT([$QAT_SYMBOLS])
597			AC_SUBST(QAT_SYMBOLS)
598		],[
599			AC_MSG_ERROR([
600	*** Please make sure the qat driver is installed then try again.
601	*** Failed to find Module.symvers in:
602	$QAT_SYMBOLS
603			])
604		])
605	])
606])
607
608dnl #
609dnl # ZFS_LINUX_CONFTEST_H
610dnl #
611AC_DEFUN([ZFS_LINUX_CONFTEST_H], [
612test -d build/$2 || mkdir -p build/$2
613cat - <<_ACEOF >build/$2/$2.h
614$1
615_ACEOF
616])
617
618dnl #
619dnl # ZFS_LINUX_CONFTEST_C
620dnl #
621AC_DEFUN([ZFS_LINUX_CONFTEST_C], [
622test -d build/$2 || mkdir -p build/$2
623cat confdefs.h - <<_ACEOF >build/$2/$2.c
624$1
625_ACEOF
626])
627
628dnl #
629dnl # ZFS_LINUX_CONFTEST_MAKEFILE
630dnl #
631dnl # $1 - test case name
632dnl # $2 - add to top-level Makefile
633dnl # $3 - additional build flags
634dnl #
635AC_DEFUN([ZFS_LINUX_CONFTEST_MAKEFILE], [
636	test -d build || mkdir -p build
637	test -d build/$1 || mkdir -p build/$1
638
639	file=build/$1/Makefile
640
641	dnl # Example command line to manually build source.
642	cat - <<_ACEOF >$file
643# Example command line to manually build source
644# make modules -C $LINUX_OBJ $ARCH_UM M=$PWD/build/$1
645
646ccflags-y := -Werror $FRAME_LARGER_THAN
647_ACEOF
648
649	dnl # Additional custom CFLAGS as requested.
650	m4_ifval($3, [echo "ccflags-y += $3" >>$file], [])
651
652	dnl # Test case source
653	echo "obj-m := $1.o" >>$file
654
655	AS_IF([test "x$2" = "xyes"], [echo "obj-m += $1/" >>build/Makefile], [])
656])
657
658dnl #
659dnl # ZFS_LINUX_TEST_PROGRAM(C)([PROLOGUE], [BODY])
660dnl #
661m4_define([ZFS_LINUX_TEST_PROGRAM], [
662#include <linux/module.h>
663$1
664
665int
666main (void)
667{
668$2
669	;
670	return 0;
671}
672
673MODULE_DESCRIPTION("conftest");
674MODULE_AUTHOR(ZFS_META_AUTHOR);
675MODULE_VERSION(ZFS_META_VERSION "-" ZFS_META_RELEASE);
676MODULE_LICENSE($3);
677])
678
679dnl #
680dnl # ZFS_LINUX_TEST_REMOVE
681dnl #
682dnl # Removes the specified test source and results.
683dnl #
684AC_DEFUN([ZFS_LINUX_TEST_REMOVE], [
685	test -d build/$1 && rm -Rf build/$1
686	test -f build/Makefile && sed '/$1/d' build/Makefile
687])
688
689dnl #
690dnl # ZFS_LINUX_COMPILE
691dnl #
692dnl # $1 - build dir
693dnl # $2 - test command
694dnl # $3 - pass command
695dnl # $4 - fail command
696dnl # $5 - set KBUILD_MODPOST_NOFINAL='yes'
697dnl # $6 - set KBUILD_MODPOST_WARN='yes'
698dnl #
699dnl # Used internally by ZFS_LINUX_TEST_{COMPILE,MODPOST}
700dnl #
701AC_DEFUN([ZFS_LINUX_COMPILE], [
702	AC_ARG_VAR([KERNEL_CC], [C compiler for
703		building kernel modules])
704	AC_ARG_VAR([KERNEL_LD], [Linker for
705		building kernel modules])
706	AC_ARG_VAR([KERNEL_LLVM], [Binary option to
707		build kernel modules with LLVM/CLANG toolchain])
708	AC_TRY_COMMAND([
709	    KBUILD_MODPOST_NOFINAL="$5" KBUILD_MODPOST_WARN="$6"
710	    make modules -k -j$TEST_JOBS ${KERNEL_CC:+CC=$KERNEL_CC}
711	    ${KERNEL_LD:+LD=$KERNEL_LD} ${KERNEL_LLVM:+LLVM=$KERNEL_LLVM}
712	    CONFIG_MODULES=y CFLAGS_MODULE=-DCONFIG_MODULES
713	    -C $LINUX_OBJ $ARCH_UM M=$PWD/$1 >$1/build.log 2>&1])
714	AS_IF([AC_TRY_COMMAND([$2])], [$3], [$4])
715])
716
717dnl #
718dnl # ZFS_LINUX_TEST_COMPILE
719dnl #
720dnl # Perform a full compile excluding the final modpost phase.
721dnl #
722AC_DEFUN([ZFS_LINUX_TEST_COMPILE], [
723	ZFS_LINUX_COMPILE([$2], [test -f $2/build.log], [
724		mv $2/Makefile $2/Makefile.compile.$1
725		mv $2/build.log $2/build.log.$1
726	],[
727	        AC_MSG_ERROR([
728        *** Unable to compile test source to determine kernel interfaces.])
729	], [yes], [])
730])
731
732dnl #
733dnl # ZFS_LINUX_TEST_MODPOST
734dnl #
735dnl # Perform a full compile including the modpost phase.  This may
736dnl # be an incremental build if the objects have already been built.
737dnl #
738AC_DEFUN([ZFS_LINUX_TEST_MODPOST], [
739	ZFS_LINUX_COMPILE([$2], [test -f $2/build.log], [
740		mv $2/Makefile $2/Makefile.modpost.$1
741		cat $2/build.log >>build/build.log.$1
742	],[
743	        AC_MSG_ERROR([
744        *** Unable to modpost test source to determine kernel interfaces.])
745	], [], [yes])
746])
747
748dnl #
749dnl # Perform the compilation of the test cases in two phases.
750dnl #
751dnl # Phase 1) attempt to build the object files for all of the tests
752dnl #          defined by the ZFS_LINUX_TEST_SRC macro.  But do not
753dnl #          perform the final modpost stage.
754dnl #
755dnl # Phase 2) disable all tests which failed the initial compilation,
756dnl #          then invoke the final modpost step for the remaining tests.
757dnl #
758dnl # This allows us efficiently build the test cases in parallel while
759dnl # remaining resilient to build failures which are expected when
760dnl # detecting the available kernel interfaces.
761dnl #
762dnl # The maximum allowed parallelism can be controlled by setting the
763dnl # TEST_JOBS environment variable.  Otherwise, it default to $(nproc).
764dnl #
765AC_DEFUN([ZFS_LINUX_TEST_COMPILE_ALL], [
766	dnl # Phase 1 - Compilation only, final linking is skipped.
767	ZFS_LINUX_TEST_COMPILE([$1], [build])
768
769	dnl #
770	dnl # Phase 2 - When building external modules disable test cases
771	dnl # which failed to compile and invoke modpost to verify the
772	dnl # final linking.
773	dnl #
774	dnl # Test names suffixed with '_license' call modpost independently
775	dnl # to ensure that a single incompatibility does not result in the
776	dnl # modpost phase exiting early.  This check is not performed on
777	dnl # every symbol since the majority are compatible and doing so
778	dnl # would significantly slow down this phase.
779	dnl #
780	dnl # When configuring for builtin (--enable-linux-builtin)
781	dnl # fake the linking step artificially create the expected .ko
782	dnl # files for tests which did compile.  This is required for
783	dnl # kernels which do not have loadable module support or have
784	dnl # not yet been built.
785	dnl #
786	AS_IF([test "x$enable_linux_builtin" = "xno"], [
787		for dir in $(awk '/^obj-m/ { print [$]3 }' \
788		    build/Makefile.compile.$1); do
789			name=${dir%/}
790			AS_IF([test -f build/$name/$name.o], [
791				AS_IF([test "${name##*_}" = "license"], [
792					ZFS_LINUX_TEST_MODPOST([$1],
793					    [build/$name])
794					echo "obj-n += $dir" >>build/Makefile
795				], [
796					echo "obj-m += $dir" >>build/Makefile
797				])
798			], [
799				echo "obj-n += $dir" >>build/Makefile
800			])
801		done
802
803		ZFS_LINUX_TEST_MODPOST([$1], [build])
804	], [
805		for dir in $(awk '/^obj-m/ { print [$]3 }' \
806		    build/Makefile.compile.$1); do
807			name=${dir%/}
808			AS_IF([test -f build/$name/$name.o], [
809				touch build/$name/$name.ko
810			])
811		done
812	])
813])
814
815dnl #
816dnl # ZFS_LINUX_TEST_SRC
817dnl #
818dnl # $1 - name
819dnl # $2 - global
820dnl # $3 - source
821dnl # $4 - extra cflags
822dnl # $5 - check license-compatibility
823dnl #
824dnl # Check if the test source is buildable at all and then if it is
825dnl # license compatible.
826dnl #
827dnl # N.B because all of the test cases are compiled in parallel they
828dnl # must never depend on the results of previous tests.  Each test
829dnl # needs to be entirely independent.
830dnl #
831AC_DEFUN([ZFS_LINUX_TEST_SRC], [
832	ZFS_LINUX_CONFTEST_C([ZFS_LINUX_TEST_PROGRAM([[$2]], [[$3]],
833	    [["Dual BSD/GPL"]])], [$1])
834	ZFS_LINUX_CONFTEST_MAKEFILE([$1], [yes], [$4])
835
836	AS_IF([ test -n "$5" ], [
837		ZFS_LINUX_CONFTEST_C([ZFS_LINUX_TEST_PROGRAM(
838		    [[$2]], [[$3]], [[$5]])], [$1_license])
839		ZFS_LINUX_CONFTEST_MAKEFILE([$1_license], [yes], [$4])
840	])
841])
842
843dnl #
844dnl # ZFS_LINUX_TEST_RESULT
845dnl #
846dnl # $1 - name of a test source (ZFS_LINUX_TEST_SRC)
847dnl # $2 - run on success (valid .ko generated)
848dnl # $3 - run on failure (unable to compile)
849dnl #
850AC_DEFUN([ZFS_LINUX_TEST_RESULT], [
851	AS_IF([test -d build/$1], [
852		AS_IF([test -f build/$1/$1.ko], [$2], [$3])
853	], [
854		AC_MSG_ERROR([
855	*** No matching source for the "$1" test, check that
856	*** both the test source and result macros refer to the same name.
857		])
858	])
859])
860
861dnl #
862dnl # ZFS_LINUX_TEST_ERROR
863dnl #
864dnl # Generic error message which can be used when none of the expected
865dnl # kernel interfaces were detected.
866dnl #
867AC_DEFUN([ZFS_LINUX_TEST_ERROR], [
868	AC_MSG_ERROR([
869	*** None of the expected "$1" interfaces were detected.
870	*** This may be because your kernel version is newer than what is
871	*** supported, or you are using a patched custom kernel with
872	*** incompatible modifications.
873	***
874	*** ZFS Version: $ZFS_META_ALIAS
875	*** Compatible Kernels: $ZFS_META_KVER_MIN - $ZFS_META_KVER_MAX
876	])
877])
878
879dnl #
880dnl # ZFS_LINUX_TEST_RESULT_SYMBOL
881dnl #
882dnl # Like ZFS_LINUX_TEST_RESULT except ZFS_CHECK_SYMBOL_EXPORT is called to
883dnl # verify symbol exports, unless --enable-linux-builtin was provided to
884dnl # configure.
885dnl #
886AC_DEFUN([ZFS_LINUX_TEST_RESULT_SYMBOL], [
887	AS_IF([ ! test -f build/$1/$1.ko], [
888		$5
889	], [
890		AS_IF([test "x$enable_linux_builtin" != "xyes"], [
891			ZFS_CHECK_SYMBOL_EXPORT([$2], [$3], [$4], [$5])
892		], [
893			$4
894		])
895	])
896])
897
898dnl #
899dnl # ZFS_LINUX_COMPILE_IFELSE
900dnl #
901AC_DEFUN([ZFS_LINUX_COMPILE_IFELSE], [
902	ZFS_LINUX_TEST_REMOVE([conftest])
903
904	m4_ifvaln([$1], [ZFS_LINUX_CONFTEST_C([$1], [conftest])])
905	m4_ifvaln([$5], [ZFS_LINUX_CONFTEST_H([$5], [conftest])],
906	    [ZFS_LINUX_CONFTEST_H([], [conftest])])
907
908	ZFS_LINUX_CONFTEST_MAKEFILE([conftest], [no],
909	    [m4_ifvaln([$5], [-I$PWD/build/conftest], [])])
910	ZFS_LINUX_COMPILE([build/conftest], [$2], [$3], [$4], [], [])
911])
912
913dnl #
914dnl # ZFS_LINUX_TRY_COMPILE
915dnl #
916dnl # $1 - global
917dnl # $2 - source
918dnl # $3 - run on success (valid .ko generated)
919dnl # $4 - run on failure (unable to compile)
920dnl #
921dnl # When configuring as builtin (--enable-linux-builtin) for kernels
922dnl # without loadable module support (CONFIG_MODULES=n) only the object
923dnl # file is created.  See ZFS_LINUX_TEST_COMPILE_ALL for details.
924dnl #
925AC_DEFUN([ZFS_LINUX_TRY_COMPILE], [
926	AS_IF([test "x$enable_linux_builtin" = "xyes"], [
927		ZFS_LINUX_COMPILE_IFELSE(
928		    [ZFS_LINUX_TEST_PROGRAM([[$1]], [[$2]],
929		    [[ZFS_META_LICENSE]])],
930		    [test -f build/conftest/conftest.o], [$3], [$4])
931	], [
932		ZFS_LINUX_COMPILE_IFELSE(
933		    [ZFS_LINUX_TEST_PROGRAM([[$1]], [[$2]],
934		    [[ZFS_META_LICENSE]])],
935		    [test -f build/conftest/conftest.ko], [$3], [$4])
936	])
937])
938
939dnl #
940dnl # ZFS_CHECK_SYMBOL_EXPORT
941dnl #
942dnl # Check if a symbol is exported on not by consulting the symbols
943dnl # file, or optionally the source code.
944dnl #
945AC_DEFUN([ZFS_CHECK_SYMBOL_EXPORT], [
946	grep -q -E '[[[:space:]]]$1[[[:space:]]]' \
947		$LINUX_OBJ/$LINUX_SYMBOLS 2>/dev/null
948	rc=$?
949	if test $rc -ne 0; then
950		export=0
951		for file in $2; do
952			grep -q -E "EXPORT_SYMBOL.*($1)" \
953				"$LINUX/$file" 2>/dev/null
954			rc=$?
955			if test $rc -eq 0; then
956				export=1
957				break;
958			fi
959		done
960		if test $export -eq 0; then :
961			$4
962		else :
963			$3
964		fi
965	else :
966		$3
967	fi
968])
969
970dnl #
971dnl # ZFS_LINUX_TRY_COMPILE_SYMBOL
972dnl #
973dnl # Like ZFS_LINUX_TRY_COMPILER except ZFS_CHECK_SYMBOL_EXPORT is called
974dnl # to verify symbol exports, unless --enable-linux-builtin was provided
975dnl # to configure.
976dnl #
977AC_DEFUN([ZFS_LINUX_TRY_COMPILE_SYMBOL], [
978	ZFS_LINUX_TRY_COMPILE([$1], [$2], [rc=0], [rc=1])
979	if test $rc -ne 0; then :
980		$6
981	else
982		if test "x$enable_linux_builtin" != xyes; then
983			ZFS_CHECK_SYMBOL_EXPORT([$3], [$4], [rc=0], [rc=1])
984		fi
985		if test $rc -ne 0; then :
986			$6
987		else :
988			$5
989		fi
990	fi
991])
992
993dnl #
994dnl # ZFS_LINUX_TRY_COMPILE_HEADER
995dnl # like ZFS_LINUX_TRY_COMPILE, except the contents conftest.h are
996dnl # provided via the fifth parameter
997dnl #
998AC_DEFUN([ZFS_LINUX_TRY_COMPILE_HEADER], [
999	AS_IF([test "x$enable_linux_builtin" = "xyes"], [
1000		ZFS_LINUX_COMPILE_IFELSE(
1001		    [ZFS_LINUX_TEST_PROGRAM([[$1]], [[$2]],
1002		    [[ZFS_META_LICENSE]])],
1003		    [test -f build/conftest/conftest.o], [$3], [$4], [$5])
1004	], [
1005		ZFS_LINUX_COMPILE_IFELSE(
1006		    [ZFS_LINUX_TEST_PROGRAM([[$1]], [[$2]],
1007		    [[ZFS_META_LICENSE]])],
1008		    [test -f build/conftest/conftest.ko], [$3], [$4], [$5])
1009	])
1010])
1011
1012dnl #
1013dnl # AS_VERSION_COMPARE_LE
1014dnl # like AS_VERSION_COMPARE_LE, but runs $3 if (and only if) $1 <= $2
1015dnl # AS_VERSION_COMPARE_LE (version-1, version-2, [action-if-less-or-equal], [action-if-greater])
1016dnl #
1017AC_DEFUN([AS_VERSION_COMPARE_LE], [
1018	AS_VERSION_COMPARE([$1], [$2], [$3], [$3], [$4])
1019])
1020
1021dnl #
1022dnl # ZFS_LINUX_REQUIRE_API
1023dnl # like ZFS_LINUX_TEST_ERROR, except only fails if the kernel is
1024dnl # at least some specified version.
1025dnl #
1026AC_DEFUN([ZFS_LINUX_REQUIRE_API], [
1027	AS_VERSION_COMPARE_LE([$2], [$kernsrcver], [
1028		AC_MSG_ERROR([
1029		*** None of the expected "$1" interfaces were detected. This
1030		*** interface is expected for kernels version "$2" and above.
1031		*** This may be because your kernel version is newer than what is
1032		*** supported, or you are using a patched custom kernel with
1033		*** incompatible modifications.  Newer kernels may have incompatible
1034		*** APIs.
1035		***
1036		*** ZFS Version: $ZFS_META_ALIAS
1037		*** Compatible Kernels: $ZFS_META_KVER_MIN - $ZFS_META_KVER_MAX
1038		])
1039	], [
1040		AC_MSG_RESULT(no)
1041	])
1042])
1043