diff mbox

[U-Boot,v5,2/5] arm: support Thumb-1 with CONFIG_SYS_THUMB_BUILD

Message ID 1437166249-17209-3-git-send-email-albert.u.boot@aribaud.net
State Superseded
Delegated to: Albert ARIBAUD
Headers show

Commit Message

Albert ARIBAUD July 17, 2015, 8:50 p.m. UTC 
When building a Thumb-1-only target with CONFIG_SYS_THUMB_BUILD,
some files fail to build, most of the time because they include
mcr instructions, which only exist for Thumb-2.

This patch introduces a Kconfig option CONFIG_THUMB2 and uses
it to select between Thumb-2 and ARM mode for the aforementioned
files.

Signed-off-by: Albert ARIBAUD <albert.u.boot@aribaud.net>
---
This patch has been build-tested and run-tested on ED Mini V2,
above the "edmini: switch to SPL" patch, and found to reduce
U-Boot size by 25% and SPL size by 14%... and to run fine. :)

This patch has also been tested against side effects on the
non-Thumb wireless_space target. The binaries produced with
and without this patch were found to differ only by their
version string.

Changes in v5: None
Changes in v4: None
Changes in v3:
- added arch/arm/lib/mem{set,cpy}.S to the list of modules
  which should always be built in ARM state.
- Selected HAS_THUMB2 for CPU_V7M.
- Fixed invalidate_l2_cache() when building for Thumb-1.

Changes in v2:
- fixed a typo in the commit message
- added file arch/arm/thumb1/include/asm/proc-armv/system.h,
  which overrides arch/arm/include/asm/proc-armv/system.h
  when building for Thumb-1 and provides non-functional but
  Thumb-compilable IRQ and FIQ related macros and functions.

 Makefile                                       |  2 +
 arch/arm/Kconfig                               |  5 ++
 arch/arm/cpu/arm926ejs/Makefile                | 11 ++++
 arch/arm/cpu/arm926ejs/cache.c                 |  5 ++
 arch/arm/include/asm/cache.h                   |  4 ++
 arch/arm/lib/Makefile                          | 24 +++++++++
 arch/arm/lib/cache.c                           | 11 ++++
 arch/arm/lib/memcpy.S                          |  4 +-
 arch/arm/lib/memset.S                          |  2 +-
 arch/arm/mach-orion5x/Makefile                 | 10 ++++
 arch/arm/thumb1/include/asm/proc-armv/system.h | 69 ++++++++++++++++++++++++++
 examples/standalone/Makefile                   | 10 ++++
 scripts/Makefile.lib                           |  3 +-
 13 files changed, 156 insertions(+), 4 deletions(-)
 create mode 100644 arch/arm/thumb1/include/asm/proc-armv/system.h

Comments

Stefan Roese Aug. 14, 2015, 7:23 a.m. UTC | #1 
Hi Albert,

On 17.07.2015 22:50, Albert ARIBAUD wrote:
> When building a Thumb-1-only target with CONFIG_SYS_THUMB_BUILD,
> some files fail to build, most of the time because they include
> mcr instructions, which only exist for Thumb-2.
>
> This patch introduces a Kconfig option CONFIG_THUMB2 and uses
> it to select between Thumb-2 and ARM mode for the aforementioned
> files.
>
> Signed-off-by: Albert ARIBAUD <albert.u.boot@aribaud.net>
> ---
> This patch has been build-tested and run-tested on ED Mini V2,
> above the "edmini: switch to SPL" patch, and found to reduce
> U-Boot size by 25% and SPL size by 14%... and to run fine. :)
>
> This patch has also been tested against side effects on the
> non-Thumb wireless_space target. The binaries produced with
> and without this patch were found to differ only by their
> version string.
>
> Changes in v5: None
> Changes in v4: None
> Changes in v3:
> - added arch/arm/lib/mem{set,cpy}.S to the list of modules
>    which should always be built in ARM state.
> - Selected HAS_THUMB2 for CPU_V7M.
> - Fixed invalidate_l2_cache() when building for Thumb-1.
>
> Changes in v2:
> - fixed a typo in the commit message
> - added file arch/arm/thumb1/include/asm/proc-armv/system.h,
>    which overrides arch/arm/include/asm/proc-armv/system.h
>    when building for Thumb-1 and provides non-functional but
>    Thumb-compilable IRQ and FIQ related macros and functions.

Whats the current status of this patch(set)? Do you plan to pull it in 
soon (when)? Or is something missing?

I'm asking since I have a ST SPEAr600 related patchset here which 
requires this THUMB1 support. And would like to commit this series soon 
as well.

Thanks,
Stefan
Stefan Roese Sept. 1, 2015, 12:48 p.m. UTC | #2 
Hi Albert,

On 14.08.2015 09:23, Stefan Roese wrote:
> On 17.07.2015 22:50, Albert ARIBAUD wrote:
>> When building a Thumb-1-only target with CONFIG_SYS_THUMB_BUILD,
>> some files fail to build, most of the time because they include
>> mcr instructions, which only exist for Thumb-2.
>>
>> This patch introduces a Kconfig option CONFIG_THUMB2 and uses
>> it to select between Thumb-2 and ARM mode for the aforementioned
>> files.
>>
>> Signed-off-by: Albert ARIBAUD <albert.u.boot@aribaud.net>
>> ---
>> This patch has been build-tested and run-tested on ED Mini V2,
>> above the "edmini: switch to SPL" patch, and found to reduce
>> U-Boot size by 25% and SPL size by 14%... and to run fine. :)
>>
>> This patch has also been tested against side effects on the
>> non-Thumb wireless_space target. The binaries produced with
>> and without this patch were found to differ only by their
>> version string.
>>
>> Changes in v5: None
>> Changes in v4: None
>> Changes in v3:
>> - added arch/arm/lib/mem{set,cpy}.S to the list of modules
>>    which should always be built in ARM state.
>> - Selected HAS_THUMB2 for CPU_V7M.
>> - Fixed invalidate_l2_cache() when building for Thumb-1.
>>
>> Changes in v2:
>> - fixed a typo in the commit message
>> - added file arch/arm/thumb1/include/asm/proc-armv/system.h,
>>    which overrides arch/arm/include/asm/proc-armv/system.h
>>    when building for Thumb-1 and provides non-functional but
>>    Thumb-compilable IRQ and FIQ related macros and functions.
>
> Whats the current status of this patch(set)? Do you plan to pull it in
> soon (when)? Or is something missing?
>
> I'm asking since I have a ST SPEAr600 related patchset here which
> requires this THUMB1 support. And would like to commit this series soon
> as well.

Sorry for bugging you again on this. Any updates? What are the plans?

Thanks,
Stefan
diff mbox

Patch

diff --git a/Makefile b/Makefile
index b6f83a5..739940c 100644
--- a/Makefile
+++ b/Makefile
@@ -607,6 +607,8 @@  KBUILD_CFLAGS += $(KCFLAGS)
 UBOOTINCLUDE    := \
 		-Iinclude \
 		$(if $(KBUILD_SRC), -I$(srctree)/include) \
+		$(if $(CONFIG_SYS_THUMB_BUILD), $(if $(CONFIG_HAS_THUMB2),, \
+			-I$(srctree)/arch/$(ARCH)/thumb1/include),) \
 		-I$(srctree)/arch/$(ARCH)/include \
 		-include $(srctree)/include/linux/kconfig.h
 
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 506463c..b29923c 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -10,6 +10,9 @@  config ARM64
 config HAS_VBAR
         bool
 
+config HAS_THUMB2
+        bool
+
 config CPU_ARM720T
         bool
 
@@ -32,9 +35,11 @@  config CPU_ARM1176
 config CPU_V7
         bool
         select HAS_VBAR
+        select HAS_THUMB2
 
 config CPU_V7M
 	bool
+        select HAS_THUMB2
 
 config CPU_PXA
         bool
diff --git a/arch/arm/cpu/arm926ejs/Makefile b/arch/arm/cpu/arm926ejs/Makefile
index 63fa159..fe78922 100644
--- a/arch/arm/cpu/arm926ejs/Makefile
+++ b/arch/arm/cpu/arm926ejs/Makefile
@@ -20,3 +20,14 @@  obj-$(CONFIG_MX25) += mx25/
 obj-$(CONFIG_MX27) += mx27/
 obj-$(if $(filter mxs,$(SOC)),y) += mxs/
 obj-$(if $(filter spear,$(SOC)),y) += spear/
+
+# some files can only build in ARM or THUMB2, not THUMB1
+
+ifdef CONFIG_SYS_THUMB_BUILD
+ifndef CONFIG_HAS_THUMB2
+
+CFLAGS_cpu.o := -marm
+CFLAGS_cache.o := -marm
+
+endif
+endif
diff --git a/arch/arm/cpu/arm926ejs/cache.c b/arch/arm/cpu/arm926ejs/cache.c
index 8d7873c..f12e365 100644
--- a/arch/arm/cpu/arm926ejs/cache.c
+++ b/arch/arm/cpu/arm926ejs/cache.c
@@ -99,4 +99,9 @@  void flush_cache(unsigned long start, unsigned long size)
 /*
  * Stub implementations for l2 cache operations
  */
+
 __weak void l2_cache_disable(void) {}
+
+#if defined CONFIG_SYS_THUMB_BUILD
+__weak void invalidate_l2_cache(void) {}
+#endif
diff --git a/arch/arm/include/asm/cache.h b/arch/arm/include/asm/cache.h
index a836e9f..1f63127 100644
--- a/arch/arm/include/asm/cache.h
+++ b/arch/arm/include/asm/cache.h
@@ -16,6 +16,9 @@ 
 /*
  * Invalidate L2 Cache using co-proc instruction
  */
+#ifdef CONFIG_SYS_THUMB_BUILD
+void invalidate_l2_cache(void);
+#else
 static inline void invalidate_l2_cache(void)
 {
 	unsigned int val=0;
@@ -24,6 +27,7 @@  static inline void invalidate_l2_cache(void)
 		: : "r" (val) : "cc");
 	isb();
 }
+#endif
 
 void l2_cache_enable(void);
 void l2_cache_disable(void);
diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile
index 31a5c8d..4c7e3f9 100644
--- a/arch/arm/lib/Makefile
+++ b/arch/arm/lib/Makefile
@@ -60,3 +60,27 @@  obj-$(CONFIG_DEBUG_LL)	+= debug.o
 ifneq (,$(findstring -mabi=aapcs-linux,$(PLATFORM_CPPFLAGS)))
 extra-y	+= eabi_compat.o
 endif
+
+# some files can only build in ARM or THUMB2, not THUMB1
+
+ifdef CONFIG_SYS_THUMB_BUILD
+ifndef CONFIG_HAS_THUMB2
+
+# for C files, just apend -marm, which will override previous -mthumb*
+
+CFLAGS_cache.o := -marm
+CFLAGS_cache-cp15.o := -marm
+
+# For .S, drop -mthumb* and other thumb-related options.
+# CFLAGS_REMOVE_* would not have an effet, so AFLAGS_REMOVE_*
+# was implemented and is used here.
+# Also, define ${target}_NO_THUMB_BUILD for these two targets
+# so that the code knows it should not use Thumb.
+
+AFLAGS_REMOVE_memset.o := -mthumb -mthumb-interwork
+AFLAGS_REMOVE_memcpy.o := -mthumb -mthumb-interwork
+AFLAGS_memset.o := -DMEMSET_NO_THUMB_BUILD
+AFLAGS_memcpy.o := -DMEMCPY_NO_THUMB_BUILD
+
+endif
+endif
diff --git a/arch/arm/lib/cache.c b/arch/arm/lib/cache.c
index 74cfde6..7c8878d 100644
--- a/arch/arm/lib/cache.c
+++ b/arch/arm/lib/cache.c
@@ -95,3 +95,14 @@  phys_addr_t noncached_alloc(size_t size, size_t align)
 	return next;
 }
 #endif /* CONFIG_SYS_NONCACHED_MEMORY */
+
+#if defined(CONFIG_SYS_THUMB_BUILD)
+void invalidate_l2_cache(void)
+{
+	unsigned int val = 0;
+
+	asm volatile("mcr p15, 1, %0, c15, c11, 0 @ invl l2 cache"
+		: : "r" (val) : "cc");
+	isb();
+}
+#endif
diff --git a/arch/arm/lib/memcpy.S b/arch/arm/lib/memcpy.S
index eeaf003..7d9fc0f 100644
--- a/arch/arm/lib/memcpy.S
+++ b/arch/arm/lib/memcpy.S
@@ -13,7 +13,7 @@ 
 #include <linux/linkage.h>
 #include <asm/assembler.h>
 
-#ifdef CONFIG_SYS_THUMB_BUILD
+#if defined(CONFIG_SYS_THUMB_BUILD) && !defined(MEMCPY_NO_THUMB_BUILD)
 #define W(instr)	instr.w
 #else
 #define W(instr)	instr
@@ -62,7 +62,7 @@ 
 
 /* Prototype: void *memcpy(void *dest, const void *src, size_t n); */
 	.syntax unified
-#ifdef CONFIG_SYS_THUMB_BUILD
+#if defined(CONFIG_SYS_THUMB_BUILD) && !defined(MEMCPY_NO_THUMB_BUILD)
 	.thumb
 	.thumb_func
 #endif
diff --git a/arch/arm/lib/memset.S b/arch/arm/lib/memset.S
index 7208f20..df053a3 100644
--- a/arch/arm/lib/memset.S
+++ b/arch/arm/lib/memset.S
@@ -16,7 +16,7 @@ 
 	.align	5
 
 	.syntax unified
-#ifdef CONFIG_SYS_THUMB_BUILD
+#if defined(CONFIG_SYS_THUMB_BUILD) && !defined(MEMSET_NO_THUMB_BUILD)
 	.thumb
 	.thumb_func
 #endif
diff --git a/arch/arm/mach-orion5x/Makefile b/arch/arm/mach-orion5x/Makefile
index 546ebcb..33dcad4 100644
--- a/arch/arm/mach-orion5x/Makefile
+++ b/arch/arm/mach-orion5x/Makefile
@@ -16,3 +16,13 @@  obj-y	+= timer.o
 ifndef CONFIG_SKIP_LOWLEVEL_INIT
 obj-y	+= lowlevel_init.o
 endif
+
+# some files can only build in ARM or THUMB2, not THUMB1
+
+ifdef CONFIG_SYS_THUMB_BUILD
+ifndef CONFIG_HAS_THUMB2
+
+CFLAGS_cpu.o := -marm
+
+endif
+endif
diff --git a/arch/arm/thumb1/include/asm/proc-armv/system.h b/arch/arm/thumb1/include/asm/proc-armv/system.h
new file mode 100644
index 0000000..7dfbf3d
--- /dev/null
+++ b/arch/arm/thumb1/include/asm/proc-armv/system.h
@@ -0,0 +1,69 @@ 
+/*
+ *  Thumb-1 drop-in for the linux/include/asm-arm/proc-armv/system.h
+ *
+ *  (C) Copyright 2015
+ *  Albert ARIBAUD <albert.u.boot@aribaud.net>
+ *
+ * The original file does not build in Thumb mode. However, in U-Boot
+ * we don't use interrupt context, so we can redefine these as empty
+ * memory barriers, which makes Thumb-1 compiler happy.
+ *
+ *  SPDX-License-Identifier:	GPL-2.0+
+ */
+
+/*
+ * Use the same macro name as linux/include/asm-arm/proc-armv/system.h
+ * here, so that if the original ever gets included after us, it won't
+ * try to re-redefine anything.
+ */
+
+#ifndef __ASM_PROC_SYSTEM_H
+#define __ASM_PROC_SYSTEM_H
+
+/*
+ * Redefine all original macros with static inline functions containing
+ * a simple memory barrier, so that they produce the same instruction
+ * ordering constraints as their original counterparts.
+ * We use static inline functions rather than macros so that we can tell
+ * the compiler to not complain about unused arguments.
+ */
+
+static inline void local_irq_save(
+	unsigned long flags __attribute__((unused)))
+{
+	__asm__ __volatile__ ("" : : : "memory");
+}
+
+static inline void local_irq_enable(void)
+{
+	__asm__ __volatile__ ("" : : : "memory");
+}
+
+static inline void local_irq_disable(void)
+{
+	__asm__ __volatile__ ("" : : : "memory");
+}
+
+static inline void __stf(void)
+{
+	__asm__ __volatile__ ("" : : : "memory");
+}
+
+static inline void __clf(void)
+{
+	__asm__ __volatile__ ("" : : : "memory");
+}
+
+static inline void local_save_flags(
+	unsigned long flags __attribute__((unused)))
+{
+	__asm__ __volatile__ ("" : : : "memory");
+}
+
+static inline void local_irq_restore(
+	unsigned long flags __attribute__((unused)))
+{
+	__asm__ __volatile__ ("" : : : "memory");
+}
+
+#endif /*  __ASM_PROC_SYSTEM_H */
diff --git a/examples/standalone/Makefile b/examples/standalone/Makefile
index 0863a8c..5a6ae00 100644
--- a/examples/standalone/Makefile
+++ b/examples/standalone/Makefile
@@ -73,3 +73,13 @@  $(obj)/%.srec: $(obj)/% FORCE
 $(obj)/%.bin: OBJCOPYFLAGS := -O binary
 $(obj)/%.bin: $(obj)/% FORCE
 	$(call if_changed,objcopy)
+
+# some files can only build in ARM or THUMB2, not THUMB1
+
+ifdef CONFIG_SYS_THUMB_BUILD
+ifndef CONFIG_HAS_THUMB2
+
+CFLAGS_stubs.o := -marm
+
+endif
+endif
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 8731fc6..3d5c872 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -104,8 +104,9 @@  modname_flags  = $(if $(filter 1,$(words $(modname))),\
 orig_c_flags   = $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(KBUILD_SUBDIR_CCFLAGS) \
                  $(ccflags-y) $(CFLAGS_$(basetarget).o)
 _c_flags       = $(filter-out $(CFLAGS_REMOVE_$(basetarget).o), $(orig_c_flags))
-_a_flags       = $(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS) $(KBUILD_SUBDIR_ASFLAGS) \
+orig_a_flags   = $(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS) $(KBUILD_SUBDIR_ASFLAGS) \
                  $(asflags-y) $(AFLAGS_$(basetarget).o)
+_a_flags       = $(filter-out $(AFLAGS_REMOVE_$(basetarget).o), $(orig_a_flags))
 _cpp_flags     = $(KBUILD_CPPFLAGS) $(cppflags-y) $(CPPFLAGS_$(@F))
 
 #