firmware: Simplify directory creation

When building the firmware blobs, use a simple loop to create
directories in $(objtree), like in Makefile.build. This simplifies the
rules and also makes it possible to set $(objtree) to '.' later. Before
this change, a dependency on $(objtree)/<dir> would be satisfied by
<dir> in $(srctree).

When installing the firmware blobs, call mkdir like in Makefile.modinst.

Cc: David Woodhouse <dwmw2@infradead.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
diff --git a/firmware/Makefile b/firmware/Makefile
index cbb09ce..6af62cf 100644
--- a/firmware/Makefile
+++ b/firmware/Makefile
@@ -138,12 +138,6 @@
 
 fw-shipped-all := $(fw-shipped-y) $(fw-shipped-m) $(fw-shipped-)
 
-# Directories which we _might_ need to create, so we have a rule for them.
-firmware-dirs := $(sort $(addprefix $(objtree)/$(obj)/,$(dir $(fw-external-y) $(fw-shipped-all))))
-
-quiet_cmd_mkdir = MKDIR   $(patsubst $(objtree)/%,%,$@)
-      cmd_mkdir = mkdir -p $@
-
 quiet_cmd_ihex  = IHEX    $@
       cmd_ihex  = $(OBJCOPY) -Iihex -Obinary $< $@
 
@@ -184,21 +178,10 @@
 		include/config/superh32.h include/config/superh64.h \
 		include/config/x86_32.h include/config/x86_64.h)
 
-# Workaround for make < 3.81, where .SECONDEXPANSION doesn't work.
-# It'll end up depending on these targets, so make them a PHONY rule which
-# depends on _all_ the directories in $(firmware-dirs), and it'll work out OK.
-PHONY += $(objtree)/$$(%) $(objtree)/$(obj)/$$(%)
-$(objtree)/$$(%) $(objtree)/$(obj)/$$(%): $(firmware-dirs)
-	@true
-
-# For the $$(dir %) trick, where we need % to be expanded first.
-.SECONDEXPANSION:
-
-$(patsubst %,$(obj)/%.gen.S, $(fw-shipped-y)): %: $(wordsize_deps) \
-		| $(objtree)/$$(dir %)
+$(patsubst %,$(obj)/%.gen.S, $(fw-shipped-y)): %: $(wordsize_deps)
 	$(call cmd,fwbin,$(patsubst %.gen.S,%,$@))
 $(patsubst %,$(obj)/%.gen.S, $(fw-external-y)): %: $(wordsize_deps) \
-		include/config/extra/firmware/dir.h | $(objtree)/$$(dir %)
+		include/config/extra/firmware/dir.h
 	$(call cmd,fwbin,$(fwabs)/$(patsubst $(obj)/%.gen.S,%,$@))
 
 # The .o files depend on the binaries directly; the .S files don't.
@@ -207,7 +190,7 @@
 
 # .ihex is used just as a simple way to hold binary files in a source tree
 # where binaries are frowned upon. They are directly converted with objcopy.
-$(obj)/%: $(obj)/%.ihex | $(objtree)/$(obj)/$$(dir %)
+$(obj)/%: $(obj)/%.ihex
 	$(call cmd,ihex)
 
 # Don't depend on ihex2fw if we're installing and it already exists.
@@ -226,16 +209,13 @@
 # is actually meaningful, because the firmware has to be loaded in a certain
 # order rather than as a single binary blob. Thus, we convert them into our
 # more compact binary representation of ihex records (<linux/ihex.h>)
-$(obj)/%.fw: $(obj)/%.HEX $(ihex2fw_dep) | $(objtree)/$(obj)/$$(dir %)
+$(obj)/%.fw: $(obj)/%.HEX $(ihex2fw_dep)
 	$(call cmd,ihex2fw)
 
 # .H16 is our own modified form of Intel HEX, with 16-bit length for records.
-$(obj)/%.fw: $(obj)/%.H16 $(ihex2fw_dep) | $(objtree)/$(obj)/$$(dir %)
+$(obj)/%.fw: $(obj)/%.H16 $(ihex2fw_dep)
 	$(call cmd,h16tofw)
 
-$(firmware-dirs):
-	$(call cmd,mkdir)
-
 obj-y				 += $(patsubst %,%.gen.o, $(fw-external-y))
 obj-$(CONFIG_FIRMWARE_IN_KERNEL) += $(patsubst %,%.gen.o, $(fw-shipped-y))