Unify target_cpu handling

Over the years several slightly different approaches were used
in the Makefiles to determine the target architecture.  This
change updates both the build system and Makefile to handle
this in a consistent fashion.

TARGET_CPU is set to i386, x86_64, powerpc, aarch6 or sparc64
and made available in the Makefiles to be used as appropriate.

Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #9848

lib/libicp/Makefile.am

@@ -9,7 +9,7 @@ AM_CFLAGS += $(FRAME_LARGER_THAN)
 
 noinst_LTLIBRARIES = libicp.la
 
-if TARGET_ASM_X86_64
+if TARGET_CPU_X86_64
 ASM_SOURCES_C = asm-x86_64/aes/aeskey.c
 ASM_SOURCES_AS = \
 	asm-x86_64/aes/aes_amd64.S \
@@ -18,22 +18,11 @@ ASM_SOURCES_AS = \
 	asm-x86_64/sha1/sha1-x86_64.S \
 	asm-x86_64/sha2/sha256_impl.S \
 	asm-x86_64/sha2/sha512_impl.S
-endif
-
-if TARGET_ASM_I386
+else
 ASM_SOURCES_C =
 ASM_SOURCES_AS =
 endif
 
-if TARGET_ASM_GENERIC
-ASM_SOURCES_C =
-ASM_SOURCES_AS =
-endif
-
-USER_C =
-
-USER_ASM =
-
 KERNEL_C = \
 	spi/kcf_spi.c \
 	api/kcf_ctxops.c \
@@ -78,8 +67,6 @@ KERNEL_C = \
 KERNEL_ASM = $(ASM_SOURCES_AS)
 
 nodist_libicp_la_SOURCES = \
-	$(USER_C) \
-	$(USER_ASM) \
 	$(KERNEL_C) \
 	$(KERNEL_ASM)
 

lib/libspl/Makefile.am

@@ -1,10 +1,20 @@
 include $(top_srcdir)/config/Rules.am
 
+if TARGET_CPU_I386
+TARGET_CPU_DIR = asm-i386
+else
+if TARGET_CPU_X86_64
+TARGET_CPU_DIR = asm-x86_64
+else
+TARGET_CPU_DIR = asm-generic
+endif
+endif
+
 VPATH = \
 	$(top_srcdir)/lib/libspl \
-	$(top_srcdir)/lib/libspl/$(TARGET_ASM_DIR)
+	$(top_srcdir)/lib/libspl/$(TARGET_CPU_DIR)
 
-SUBDIRS = include $(TARGET_ASM_DIR)
+SUBDIRS = include $(TARGET_CPU_DIR)
 DIST_SUBDIRS = include asm-generic asm-i386 asm-x86_64
 
 AM_CFLAGS += $(LIBTIRPC_CFLAGS)

lib/libspl/asm-generic/.gitignore

@@ -0,0 +1 @@
+/atomic.S