X-Git-Url: https://git.karo-electronics.de/?a=blobdiff_plain;f=Makefile;h=ce239fc28ebcdb83b49654022f53ac76e440c9ce;hb=ed9249764462a26633a43180ab30efe0fa65adfb;hp=54430f933b628ca99bdbc1e2bf5dd2570ca0354c;hpb=c25b87dcbaeb50fa0803a6a35fc55f3c00fefc7b;p=karo-tx-linux.git

diff --git a/Makefile b/Makefile
index 54430f933b62..ce239fc28ebc 100644
--- a/Makefile
+++ b/Makefile
@@ -10,9 +10,10 @@ NAME = Hurr durr I'ma sheep
 # Comments in this file are targeted only to the developer, do not
 # expect to learn how to build the kernel reading this file.
 
-# Do not use make's built-in rules and variables
-# (this increases performance and avoids hard-to-debug behaviour);
-MAKEFLAGS += -rR
+# o Do not use make's built-in rules and variables
+#   (this increases performance and avoids hard-to-debug behaviour);
+# o Look for make include files relative to root of kernel src
+MAKEFLAGS += -rR --include-dir=$(CURDIR)
 
 # Avoid funny character set dependencies
 unexport LC_ALL
@@ -344,19 +345,21 @@ endif
 export COMPILER
 endif
 
-# Look for make include files relative to root of kernel src
-MAKEFLAGS += --include-dir=$(srctree)
-
 # We need some generic definitions (do not try to remake the file).
-$(srctree)/scripts/Kbuild.include: ;
-include $(srctree)/scripts/Kbuild.include
+scripts/Kbuild.include: ;
+include scripts/Kbuild.include
 
 # Make variables (CC, etc...)
 AS		= $(CROSS_COMPILE)as
 LD		= $(CROSS_COMPILE)ld
+LDFINAL	= $(LD)
 CC		= $(CROSS_COMPILE)gcc
 CPP		= $(CC) -E
+ifdef CONFIG_LTO
+AR		= $(CROSS_COMPILE)gcc-ar
+else
 AR		= $(CROSS_COMPILE)ar
+endif
 NM		= $(CROSS_COMPILE)nm
 STRIP		= $(CROSS_COMPILE)strip
 OBJCOPY		= $(CROSS_COMPILE)objcopy
@@ -418,7 +421,7 @@ KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(S
 
 export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
 export ARCH SRCARCH CONFIG_SHELL HOSTCC HOSTCFLAGS CROSS_COMPILE AS LD CC
-export CPP AR NM STRIP OBJCOPY OBJDUMP
+export CPP AR NM STRIP OBJCOPY OBJDUMP LDFINAL
 export MAKE AWK GENKSYMS INSTALLKERNEL PERL PYTHON UTS_MACHINE
 export HOSTCXX HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS
 
@@ -429,6 +432,17 @@ export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
 export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
 export KBUILD_ARFLAGS
 
+ifdef CONFIG_LTO
+# LTO gcc creates a lot of files in TMPDIR, and with /tmp as tmpfs
+# it's easy to drive the machine OOM. Use the object directory
+# instead.
+ifndef TMPDIR
+TMPDIR ?= $(objtree)
+export TMPDIR
+$(info setting TMPDIR=$(objtree) for LTO build)
+endif
+endif
+
 # When compiling out-of-tree modules, put MODVERDIR in the module
 # tree rather than in the kernel tree. The kernel tree might
 # even be read-only.
@@ -533,7 +547,7 @@ ifeq ($(config-targets),1)
 # Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
 # KBUILD_DEFCONFIG may point out an alternative default configuration
 # used for 'make defconfig'
-include $(srctree)/arch/$(SRCARCH)/Makefile
+include arch/$(SRCARCH)/Makefile
 export KBUILD_DEFCONFIG KBUILD_KCONFIG
 
 config: scripts_basic outputmakefile FORCE
@@ -609,7 +623,7 @@ endif # $(dot-config)
 # Defaults to vmlinux, but the arch makefile usually adds further targets
 all: vmlinux
 
-include $(srctree)/arch/$(SRCARCH)/Makefile
+include arch/$(SRCARCH)/Makefile
 
 KBUILD_CFLAGS	+= $(call cc-option,-fno-delete-null-pointer-checks,)
 
@@ -781,8 +795,9 @@ ifeq ($(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-goto.sh $(CC)), y)
 	KBUILD_CFLAGS += -DCC_HAVE_ASM_GOTO
 endif
 
-include $(srctree)/scripts/Makefile.kasan
-include $(srctree)/scripts/Makefile.extrawarn
+include scripts/Makefile.kasan
+include scripts/Makefile.extrawarn
+include scripts/Makefile.lto
 
 # Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments
 KBUILD_CPPFLAGS += $(KCPPFLAGS)
@@ -1025,12 +1040,6 @@ headerdep:
 	$(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
 	$(srctree)/scripts/headerdep.pl -I$(srctree)/include
 
-# ---------------------------------------------------------------------------
-
-PHONY += depend dep
-depend dep:
-	@echo '*** Warning: make $@ is unnecessary now.'
-
 # ---------------------------------------------------------------------------
 # Firmware install
 INSTALL_FW_PATH=$(INSTALL_MOD_PATH)/lib/firmware