2019-04-08 21:31:09

by Stefan Agner

[permalink] [raw]
Subject: [PATCH v2 1/3] ARM: use arch_extension directive instead of arch argument

The LLVM Target parser currently does not allow to specify the security
extension as part of -march (see also LLVM Bug 40186 [0]). When trying
to use Clang with LLVM's integrated assembler, this leads to build
errors such as this:
clang-8: error: the clang compiler does not support '-Wa,-march=armv7-a+sec'

Use ".arch_extension sec" to enable the security extension in a more
portable fasion. Also make sure to use ".arch armv7-a" in case a v6/v7
multi-platform kernel is being built.

Note that this is technically not exactly the same as the old code
checked for availabilty of the security extension by calling as-instr.
However, there are already other sites which use ".arch_extension sec"
unconditionally, hence de-facto we need an assembler capable of
".arch_extension sec" already today (arch/arm/mm/proc-v7.S). The
arch extension "sec" is available since binutils 2.21 according to
its documentation [1].

[0] https://bugs.llvm.org/show_bug.cgi?id=40186
[1] https://sourceware.org/binutils/docs-2.21/as/ARM-Options.html

Signed-off-by: Stefan Agner <[email protected]>
Acked-by: Mans Rullgard <[email protected]>
Acked-by: Arnd Bergmann <[email protected]>
Acked-by: Krzysztof Kozlowski <[email protected]>
---
Changes since v1:
- Explicitly specify assembler architecture as armv7-a to avoid
build issues when bulding v6/v7 multi arch kernel.

arch/arm/mach-bcm/Makefile | 3 ---
arch/arm/mach-bcm/bcm_kona_smc.c | 2 --
arch/arm/mach-exynos/Makefile | 4 ----
arch/arm/mach-exynos/exynos-smc.S | 3 ++-
arch/arm/mach-exynos/sleep.S | 3 ++-
arch/arm/mach-highbank/Makefile | 3 ---
arch/arm/mach-highbank/smc.S | 3 ++-
arch/arm/mach-keystone/Makefile | 3 ---
arch/arm/mach-keystone/smc.S | 1 +
arch/arm/mach-omap2/Makefile | 8 --------
arch/arm/mach-omap2/omap-headsmp.S | 2 ++
arch/arm/mach-omap2/omap-smc.S | 3 ++-
arch/arm/mach-omap2/sleep33xx.S | 1 +
arch/arm/mach-omap2/sleep34xx.S | 2 ++
arch/arm/mach-omap2/sleep43xx.S | 2 ++
arch/arm/mach-omap2/sleep44xx.S | 2 ++
arch/arm/mach-tango/Makefile | 3 ---
arch/arm/mach-tango/smc.S | 1 +
18 files changed, 19 insertions(+), 30 deletions(-)

diff --git a/arch/arm/mach-bcm/Makefile b/arch/arm/mach-bcm/Makefile
index 8fd23b263c60..b59c813b1af4 100644
--- a/arch/arm/mach-bcm/Makefile
+++ b/arch/arm/mach-bcm/Makefile
@@ -40,9 +40,6 @@ obj-$(CONFIG_ARCH_BCM_MOBILE_L2_CACHE) += kona_l2_cache.o

# Support for secure monitor traps
obj-$(CONFIG_ARCH_BCM_MOBILE_SMC) += bcm_kona_smc.o
-ifeq ($(call as-instr,.arch_extension sec,as_has_sec),as_has_sec)
-CFLAGS_bcm_kona_smc.o += -Wa,-march=armv7-a+sec -DREQUIRES_SEC
-endif

# BCM2835
obj-$(CONFIG_ARCH_BCM2835) += board_bcm2835.o
diff --git a/arch/arm/mach-bcm/bcm_kona_smc.c b/arch/arm/mach-bcm/bcm_kona_smc.c
index a55a7ecf146a..541e850a736c 100644
--- a/arch/arm/mach-bcm/bcm_kona_smc.c
+++ b/arch/arm/mach-bcm/bcm_kona_smc.c
@@ -125,9 +125,7 @@ static int bcm_kona_do_smc(u32 service_id, u32 buffer_phys)
__asmeq("%2", "r4")
__asmeq("%3", "r5")
__asmeq("%4", "r6")
-#ifdef REQUIRES_SEC
".arch_extension sec\n"
-#endif
" smc #0\n"
: "=r" (ip), "=r" (r0)
: "r" (r4), "r" (r5), "r" (r6)
diff --git a/arch/arm/mach-exynos/Makefile b/arch/arm/mach-exynos/Makefile
index cd00c82a1add..44de9f36fd1b 100644
--- a/arch/arm/mach-exynos/Makefile
+++ b/arch/arm/mach-exynos/Makefile
@@ -14,9 +14,5 @@ obj-$(CONFIG_PM_SLEEP) += suspend.o

obj-$(CONFIG_SMP) += platsmp.o headsmp.o

-plus_sec := $(call as-instr,.arch_extension sec,+sec)
-AFLAGS_exynos-smc.o :=-Wa,-march=armv7-a$(plus_sec)
-AFLAGS_sleep.o :=-Wa,-march=armv7-a$(plus_sec)
-
obj-$(CONFIG_EXYNOS5420_MCPM) += mcpm-exynos.o
CFLAGS_mcpm-exynos.o += -march=armv7-a
diff --git a/arch/arm/mach-exynos/exynos-smc.S b/arch/arm/mach-exynos/exynos-smc.S
index d259532ba937..6da31e6a7acb 100644
--- a/arch/arm/mach-exynos/exynos-smc.S
+++ b/arch/arm/mach-exynos/exynos-smc.S
@@ -10,7 +10,8 @@
/*
* Function signature: void exynos_smc(u32 cmd, u32 arg1, u32 arg2, u32 arg3)
*/
-
+ .arch armv7-a
+ .arch_extension sec
ENTRY(exynos_smc)
stmfd sp!, {r4-r11, lr}
dsb
diff --git a/arch/arm/mach-exynos/sleep.S b/arch/arm/mach-exynos/sleep.S
index 2783c3a0c06a..ed93f91853b8 100644
--- a/arch/arm/mach-exynos/sleep.S
+++ b/arch/arm/mach-exynos/sleep.S
@@ -44,7 +44,8 @@ ENTRY(exynos_cpu_resume)
ENDPROC(exynos_cpu_resume)

.align
-
+ .arch armv7-a
+ .arch_extension sec
ENTRY(exynos_cpu_resume_ns)
mrc p15, 0, r0, c0, c0, 0
ldr r1, =CPU_MASK
diff --git a/arch/arm/mach-highbank/Makefile b/arch/arm/mach-highbank/Makefile
index 55840f414d3e..e7741b883d13 100644
--- a/arch/arm/mach-highbank/Makefile
+++ b/arch/arm/mach-highbank/Makefile
@@ -1,6 +1,3 @@
obj-y := highbank.o system.o smc.o

-plus_sec := $(call as-instr,.arch_extension sec,+sec)
-AFLAGS_smc.o :=-Wa,-march=armv7-a$(plus_sec)
-
obj-$(CONFIG_PM_SLEEP) += pm.o
diff --git a/arch/arm/mach-highbank/smc.S b/arch/arm/mach-highbank/smc.S
index 407d17baaaa9..860a79135b7b 100644
--- a/arch/arm/mach-highbank/smc.S
+++ b/arch/arm/mach-highbank/smc.S
@@ -16,7 +16,8 @@
* the monitor API number.
* Function signature : void highbank_smc1(u32 fn, u32 arg)
*/
-
+ .arch armv7-a
+ .arch_extension sec
ENTRY(highbank_smc1)
stmfd sp!, {r4-r11, lr}
mov r12, r0
diff --git a/arch/arm/mach-keystone/Makefile b/arch/arm/mach-keystone/Makefile
index f8b0dccac8dc..739b38be5696 100644
--- a/arch/arm/mach-keystone/Makefile
+++ b/arch/arm/mach-keystone/Makefile
@@ -1,9 +1,6 @@
# SPDX-License-Identifier: GPL-2.0
obj-y := keystone.o smc.o

-plus_sec := $(call as-instr,.arch_extension sec,+sec)
-AFLAGS_smc.o :=-Wa,-march=armv7-a$(plus_sec)
-
obj-$(CONFIG_SMP) += platsmp.o

# PM domain driver for Keystone SOCs
diff --git a/arch/arm/mach-keystone/smc.S b/arch/arm/mach-keystone/smc.S
index d15de8179fab..ec03dc499270 100644
--- a/arch/arm/mach-keystone/smc.S
+++ b/arch/arm/mach-keystone/smc.S
@@ -21,6 +21,7 @@
*
* Return: Non zero value on failure
*/
+ .arch_extension sec
ENTRY(keystone_cpu_smc)
stmfd sp!, {r4-r11, lr}
smc #0
diff --git a/arch/arm/mach-omap2/Makefile b/arch/arm/mach-omap2/Makefile
index 85d1b13c9215..f1d283995b31 100644
--- a/arch/arm/mach-omap2/Makefile
+++ b/arch/arm/mach-omap2/Makefile
@@ -41,11 +41,6 @@ obj-$(CONFIG_SOC_OMAP5) += $(omap-4-5-common) $(smp-y) sleep44xx.o
obj-$(CONFIG_SOC_AM43XX) += $(omap-4-5-common)
obj-$(CONFIG_SOC_DRA7XX) += $(omap-4-5-common) $(smp-y) sleep44xx.o

-plus_sec := $(call as-instr,.arch_extension sec,+sec)
-AFLAGS_omap-headsmp.o :=-Wa,-march=armv7-a$(plus_sec)
-AFLAGS_omap-smc.o :=-Wa,-march=armv7-a$(plus_sec)
-AFLAGS_sleep44xx.o :=-Wa,-march=armv7-a$(plus_sec)
-
# Functions loaded to SRAM
obj-$(CONFIG_SOC_OMAP2420) += sram242x.o
obj-$(CONFIG_SOC_OMAP2430) += sram243x.o
@@ -95,9 +90,6 @@ obj-$(CONFIG_POWER_AVS_OMAP) += sr_device.o
obj-$(CONFIG_POWER_AVS_OMAP_CLASS3) += smartreflex-class3.o

AFLAGS_sleep24xx.o :=-Wa,-march=armv6
-AFLAGS_sleep34xx.o :=-Wa,-march=armv7-a$(plus_sec)
-AFLAGS_sleep33xx.o :=-Wa,-march=armv7-a$(plus_sec)
-AFLAGS_sleep43xx.o :=-Wa,-march=armv7-a$(plus_sec)

endif

diff --git a/arch/arm/mach-omap2/omap-headsmp.S b/arch/arm/mach-omap2/omap-headsmp.S
index 4c6f14cf92a8..b26c0daaa3c1 100644
--- a/arch/arm/mach-omap2/omap-headsmp.S
+++ b/arch/arm/mach-omap2/omap-headsmp.S
@@ -58,6 +58,8 @@ ENDPROC(omap5_secondary_startup)
* omap5_secondary_startup if the primary CPU was put into HYP mode by
* the boot loader.
*/
+ .arch armv7-a
+ .arch_extension sec
ENTRY(omap5_secondary_hyp_startup)
wait_2: ldr r2, =AUX_CORE_BOOT0_PA @ read from AuxCoreBoot0
ldr r0, [r2]
diff --git a/arch/arm/mach-omap2/omap-smc.S b/arch/arm/mach-omap2/omap-smc.S
index 72506e6cf9e7..a14aee5e81d1 100644
--- a/arch/arm/mach-omap2/omap-smc.S
+++ b/arch/arm/mach-omap2/omap-smc.S
@@ -23,7 +23,8 @@
* link register "lr".
* Function signature : void omap_smc1(u32 fn, u32 arg)
*/
-
+ .arch armv7-a
+ .arch_extension sec
ENTRY(omap_smc1)
stmfd sp!, {r2-r12, lr}
mov r12, r0
diff --git a/arch/arm/mach-omap2/sleep33xx.S b/arch/arm/mach-omap2/sleep33xx.S
index 47a816468cdb..68fee339d3f1 100644
--- a/arch/arm/mach-omap2/sleep33xx.S
+++ b/arch/arm/mach-omap2/sleep33xx.S
@@ -24,6 +24,7 @@
#define BIT(nr) (1 << (nr))

.arm
+ .arch armv7-a
.align 3

ENTRY(am33xx_do_wfi)
diff --git a/arch/arm/mach-omap2/sleep34xx.S b/arch/arm/mach-omap2/sleep34xx.S
index 22daf4efed68..4927304b5902 100644
--- a/arch/arm/mach-omap2/sleep34xx.S
+++ b/arch/arm/mach-omap2/sleep34xx.S
@@ -97,6 +97,8 @@ ENDPROC(enable_omap3630_toggle_l2_on_restore)
*
* r0 = physical address of the parameters
*/
+ .arch armv7-a
+ .arch_extension sec
ENTRY(save_secure_ram_context)
stmfd sp!, {r4 - r11, lr} @ save registers on stack
mov r3, r0 @ physical address of parameters
diff --git a/arch/arm/mach-omap2/sleep43xx.S b/arch/arm/mach-omap2/sleep43xx.S
index 5b9343b58fc7..31dda92d9d03 100644
--- a/arch/arm/mach-omap2/sleep43xx.S
+++ b/arch/arm/mach-omap2/sleep43xx.S
@@ -56,6 +56,8 @@
#define RTC_PMIC_EXT_WAKEUP_EN BIT(0)

.arm
+ .arch armv7-a
+ .arch_extension sec
.align 3

ENTRY(am43xx_do_wfi)
diff --git a/arch/arm/mach-omap2/sleep44xx.S b/arch/arm/mach-omap2/sleep44xx.S
index 0cae3b070208..3e6da3bd9dfd 100644
--- a/arch/arm/mach-omap2/sleep44xx.S
+++ b/arch/arm/mach-omap2/sleep44xx.S
@@ -23,6 +23,8 @@

#if defined(CONFIG_SMP) && defined(CONFIG_PM)

+ .arch armv7-a
+ .arch_extension sec
.macro DO_SMC
dsb
smc #0
diff --git a/arch/arm/mach-tango/Makefile b/arch/arm/mach-tango/Makefile
index da6c633d3cc0..97cd04508fa1 100644
--- a/arch/arm/mach-tango/Makefile
+++ b/arch/arm/mach-tango/Makefile
@@ -1,7 +1,4 @@
# SPDX-License-Identifier: GPL-2.0
-plus_sec := $(call as-instr,.arch_extension sec,+sec)
-AFLAGS_smc.o := -Wa,-march=armv7-a$(plus_sec)
-
obj-y += setup.o smc.o
obj-$(CONFIG_SMP) += platsmp.o
obj-$(CONFIG_SUSPEND) += pm.o
diff --git a/arch/arm/mach-tango/smc.S b/arch/arm/mach-tango/smc.S
index 361a8dc89804..cf2d21e5226c 100644
--- a/arch/arm/mach-tango/smc.S
+++ b/arch/arm/mach-tango/smc.S
@@ -1,6 +1,7 @@
/* SPDX-License-Identifier: GPL-2.0 */
#include <linux/linkage.h>

+ .arch_extension sec
ENTRY(tango_smc)
push {lr}
mov ip, r1
--
2.21.0


2019-04-08 21:30:45

by Stefan Agner

[permalink] [raw]
Subject: [PATCH v2 3/3] ARM: mvebu: prefix coprocessor operand with p

In every other instance where mrc is used the coprocessor operand
is prefix with p (e.g. p15). Use the p prefix in this case too.
This fixes a build issue when using LLVM's integrated assembler:
arch/arm/mach-mvebu/coherency_ll.S:69:6: error: invalid operand for instruction
mrc 15, 0, r3, cr0, cr0, 5
^
arch/arm/mach-mvebu/pmsu_ll.S:19:6: error: invalid operand for instruction
mrc 15, 0, r0, cr0, cr0, 5 @ get the CPU ID
^

Signed-off-by: Stefan Agner <[email protected]>
Acked-by: Nicolas Pitre <[email protected]>
---
arch/arm/mach-mvebu/coherency_ll.S | 2 +-
arch/arm/mach-mvebu/pmsu_ll.S | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm/mach-mvebu/coherency_ll.S b/arch/arm/mach-mvebu/coherency_ll.S
index 8b2fbc8b6bc6..2d962fe48821 100644
--- a/arch/arm/mach-mvebu/coherency_ll.S
+++ b/arch/arm/mach-mvebu/coherency_ll.S
@@ -66,7 +66,7 @@ ENDPROC(ll_get_coherency_base)
* fabric registers
*/
ENTRY(ll_get_coherency_cpumask)
- mrc 15, 0, r3, cr0, cr0, 5
+ mrc p15, 0, r3, cr0, cr0, 5
and r3, r3, #15
mov r2, #(1 << 24)
lsl r3, r2, r3
diff --git a/arch/arm/mach-mvebu/pmsu_ll.S b/arch/arm/mach-mvebu/pmsu_ll.S
index c1fb713e9306..7aae9a25cfeb 100644
--- a/arch/arm/mach-mvebu/pmsu_ll.S
+++ b/arch/arm/mach-mvebu/pmsu_ll.S
@@ -16,7 +16,7 @@
ENTRY(armada_38x_scu_power_up)
mrc p15, 4, r1, c15, c0 @ get SCU base address
orr r1, r1, #0x8 @ SCU CPU Power Status Register
- mrc 15, 0, r0, cr0, cr0, 5 @ get the CPU ID
+ mrc p15, 0, r0, cr0, cr0, 5 @ get the CPU ID
and r0, r0, #15
add r1, r1, r0
mov r0, #0x0
--
2.21.0

2019-04-08 21:55:57

by Stefan Agner

[permalink] [raw]
Subject: [PATCH v2 2/3] ARM: mvebu: drop unnecessary label

The label mvebu_boot_wa_start is not necessary and causes a build
issue when building with LLVM's integrated assembler:
AS arch/arm/mach-mvebu/pmsu_ll.o
arch/arm/mach-mvebu/pmsu_ll.S:59:1: error: invalid symbol redefinition
mvebu_boot_wa_start:
^

Drop the label.

Signed-off-by: Stefan Agner <[email protected]>
Acked-by: Nicolas Pitre <[email protected]>
---
arch/arm/mach-mvebu/pmsu_ll.S | 1 -
1 file changed, 1 deletion(-)

diff --git a/arch/arm/mach-mvebu/pmsu_ll.S b/arch/arm/mach-mvebu/pmsu_ll.S
index 88651221dbdd..c1fb713e9306 100644
--- a/arch/arm/mach-mvebu/pmsu_ll.S
+++ b/arch/arm/mach-mvebu/pmsu_ll.S
@@ -56,7 +56,6 @@ ENDPROC(armada_38x_cpu_resume)

/* The following code will be executed from SRAM */
ENTRY(mvebu_boot_wa_start)
-mvebu_boot_wa_start:
ARM_BE8(setend be)
adr r0, 1f
ldr r0, [r0] @ load the address of the
--
2.21.0

2019-04-09 12:27:13

by Måns Rullgård

[permalink] [raw]
Subject: Re: [PATCH v2 1/3] ARM: use arch_extension directive instead of arch argument

Stefan Agner <[email protected]> writes:

> The LLVM Target parser currently does not allow to specify the security
> extension as part of -march (see also LLVM Bug 40186 [0]). When trying
> to use Clang with LLVM's integrated assembler, this leads to build
> errors such as this:
> clang-8: error: the clang compiler does not support '-Wa,-march=armv7-a+sec'
>
> Use ".arch_extension sec" to enable the security extension in a more
> portable fasion. Also make sure to use ".arch armv7-a" in case a v6/v7
> multi-platform kernel is being built.
>
> Note that this is technically not exactly the same as the old code
> checked for availabilty of the security extension by calling as-instr.
> However, there are already other sites which use ".arch_extension sec"
> unconditionally, hence de-facto we need an assembler capable of
> ".arch_extension sec" already today (arch/arm/mm/proc-v7.S). The
> arch extension "sec" is available since binutils 2.21 according to
> its documentation [1].
>
> [0] https://bugs.llvm.org/show_bug.cgi?id=40186
> [1] https://sourceware.org/binutils/docs-2.21/as/ARM-Options.html
>
> Signed-off-by: Stefan Agner <[email protected]>
> Acked-by: Mans Rullgard <[email protected]>
> Acked-by: Arnd Bergmann <[email protected]>
> Acked-by: Krzysztof Kozlowski <[email protected]>
> ---
> Changes since v1:
> - Explicitly specify assembler architecture as armv7-a to avoid
> build issues when bulding v6/v7 multi arch kernel.
>
> arch/arm/mach-bcm/Makefile | 3 ---
> arch/arm/mach-bcm/bcm_kona_smc.c | 2 --
> arch/arm/mach-exynos/Makefile | 4 ----
> arch/arm/mach-exynos/exynos-smc.S | 3 ++-
> arch/arm/mach-exynos/sleep.S | 3 ++-
> arch/arm/mach-highbank/Makefile | 3 ---
> arch/arm/mach-highbank/smc.S | 3 ++-
> arch/arm/mach-keystone/Makefile | 3 ---
> arch/arm/mach-keystone/smc.S | 1 +
> arch/arm/mach-omap2/Makefile | 8 --------
> arch/arm/mach-omap2/omap-headsmp.S | 2 ++
> arch/arm/mach-omap2/omap-smc.S | 3 ++-
> arch/arm/mach-omap2/sleep33xx.S | 1 +
> arch/arm/mach-omap2/sleep34xx.S | 2 ++
> arch/arm/mach-omap2/sleep43xx.S | 2 ++
> arch/arm/mach-omap2/sleep44xx.S | 2 ++
> arch/arm/mach-tango/Makefile | 3 ---
> arch/arm/mach-tango/smc.S | 1 +
> 18 files changed, 19 insertions(+), 30 deletions(-)

[...]

> diff --git a/arch/arm/mach-bcm/bcm_kona_smc.c b/arch/arm/mach-bcm/bcm_kona_smc.c
> index a55a7ecf146a..541e850a736c 100644
> --- a/arch/arm/mach-bcm/bcm_kona_smc.c
> +++ b/arch/arm/mach-bcm/bcm_kona_smc.c
> @@ -125,9 +125,7 @@ static int bcm_kona_do_smc(u32 service_id, u32 buffer_phys)
> __asmeq("%2", "r4")
> __asmeq("%3", "r5")
> __asmeq("%4", "r6")
> -#ifdef REQUIRES_SEC
> ".arch_extension sec\n"
> -#endif
> " smc #0\n"
> : "=r" (ip), "=r" (r0)
> : "r" (r4), "r" (r5), "r" (r6)

[...]

> diff --git a/arch/arm/mach-keystone/smc.S b/arch/arm/mach-keystone/smc.S
> index d15de8179fab..ec03dc499270 100644
> --- a/arch/arm/mach-keystone/smc.S
> +++ b/arch/arm/mach-keystone/smc.S
> @@ -21,6 +21,7 @@
> *
> * Return: Non zero value on failure
> */
> + .arch_extension sec
> ENTRY(keystone_cpu_smc)
> stmfd sp!, {r4-r11, lr}
> smc #0

[...]

> diff --git a/arch/arm/mach-tango/smc.S b/arch/arm/mach-tango/smc.S
> index 361a8dc89804..cf2d21e5226c 100644
> --- a/arch/arm/mach-tango/smc.S
> +++ b/arch/arm/mach-tango/smc.S
> @@ -1,6 +1,7 @@
> /* SPDX-License-Identifier: GPL-2.0 */
> #include <linux/linkage.h>
>
> + .arch_extension sec
> ENTRY(tango_smc)
> push {lr}
> mov ip, r1

Is there some reason these three don't need the .arch directive?

--
M?ns Rullg?rd

2019-04-09 14:52:26

by Tony Lindgren

[permalink] [raw]
Subject: Re: [PATCH v2 1/3] ARM: use arch_extension directive instead of arch argument

Hi,

* Stefan Agner <[email protected]> [190408 20:59]:
> --- a/arch/arm/mach-omap2/Makefile
> +++ b/arch/arm/mach-omap2/Makefile
> @@ -41,11 +41,6 @@ obj-$(CONFIG_SOC_OMAP5) += $(omap-4-5-common) $(smp-y) sleep44xx.o
> obj-$(CONFIG_SOC_AM43XX) += $(omap-4-5-common)
> obj-$(CONFIG_SOC_DRA7XX) += $(omap-4-5-common) $(smp-y) sleep44xx.o
>
> -plus_sec := $(call as-instr,.arch_extension sec,+sec)
> -AFLAGS_omap-headsmp.o :=-Wa,-march=armv7-a$(plus_sec)
> -AFLAGS_omap-smc.o :=-Wa,-march=armv7-a$(plus_sec)
> -AFLAGS_sleep44xx.o :=-Wa,-march=armv7-a$(plus_sec)
> -
> # Functions loaded to SRAM
> obj-$(CONFIG_SOC_OMAP2420) += sram242x.o
> obj-$(CONFIG_SOC_OMAP2430) += sram243x.o
> @@ -95,9 +90,6 @@ obj-$(CONFIG_POWER_AVS_OMAP) += sr_device.o
> obj-$(CONFIG_POWER_AVS_OMAP_CLASS3) += smartreflex-class3.o
>
> AFLAGS_sleep24xx.o :=-Wa,-march=armv6
> -AFLAGS_sleep34xx.o :=-Wa,-march=armv7-a$(plus_sec)
> -AFLAGS_sleep33xx.o :=-Wa,-march=armv7-a$(plus_sec)
> -AFLAGS_sleep43xx.o :=-Wa,-march=armv7-a$(plus_sec)

I think we should also change the AFLAGS_sleep24xx.o above the
same way but with armv6 flags. This can be build tested with
omap2plus_defconfig.

Regards,

Tony

2019-04-09 15:08:02

by Stefan Agner

[permalink] [raw]
Subject: Re: [PATCH v2 1/3] ARM: use arch_extension directive instead of arch argument

On 09.04.2019 14:25, Måns Rullgård wrote:
> Stefan Agner <[email protected]> writes:
>
>> The LLVM Target parser currently does not allow to specify the security
>> extension as part of -march (see also LLVM Bug 40186 [0]). When trying
>> to use Clang with LLVM's integrated assembler, this leads to build
>> errors such as this:
>> clang-8: error: the clang compiler does not support '-Wa,-march=armv7-a+sec'
>>
>> Use ".arch_extension sec" to enable the security extension in a more
>> portable fasion. Also make sure to use ".arch armv7-a" in case a v6/v7
>> multi-platform kernel is being built.
>>
>> Note that this is technically not exactly the same as the old code
>> checked for availabilty of the security extension by calling as-instr.
>> However, there are already other sites which use ".arch_extension sec"
>> unconditionally, hence de-facto we need an assembler capable of
>> ".arch_extension sec" already today (arch/arm/mm/proc-v7.S). The
>> arch extension "sec" is available since binutils 2.21 according to
>> its documentation [1].
>>
>> [0] https://bugs.llvm.org/show_bug.cgi?id=40186
>> [1] https://sourceware.org/binutils/docs-2.21/as/ARM-Options.html
>>
>> Signed-off-by: Stefan Agner <[email protected]>
>> Acked-by: Mans Rullgard <[email protected]>
>> Acked-by: Arnd Bergmann <[email protected]>
>> Acked-by: Krzysztof Kozlowski <[email protected]>
>> ---
>> Changes since v1:
>> - Explicitly specify assembler architecture as armv7-a to avoid
>> build issues when bulding v6/v7 multi arch kernel.
>>
>> arch/arm/mach-bcm/Makefile | 3 ---
>> arch/arm/mach-bcm/bcm_kona_smc.c | 2 --
>> arch/arm/mach-exynos/Makefile | 4 ----
>> arch/arm/mach-exynos/exynos-smc.S | 3 ++-
>> arch/arm/mach-exynos/sleep.S | 3 ++-
>> arch/arm/mach-highbank/Makefile | 3 ---
>> arch/arm/mach-highbank/smc.S | 3 ++-
>> arch/arm/mach-keystone/Makefile | 3 ---
>> arch/arm/mach-keystone/smc.S | 1 +
>> arch/arm/mach-omap2/Makefile | 8 --------
>> arch/arm/mach-omap2/omap-headsmp.S | 2 ++
>> arch/arm/mach-omap2/omap-smc.S | 3 ++-
>> arch/arm/mach-omap2/sleep33xx.S | 1 +
>> arch/arm/mach-omap2/sleep34xx.S | 2 ++
>> arch/arm/mach-omap2/sleep43xx.S | 2 ++
>> arch/arm/mach-omap2/sleep44xx.S | 2 ++
>> arch/arm/mach-tango/Makefile | 3 ---
>> arch/arm/mach-tango/smc.S | 1 +
>> 18 files changed, 19 insertions(+), 30 deletions(-)
>
> [...]
>
>> diff --git a/arch/arm/mach-bcm/bcm_kona_smc.c b/arch/arm/mach-bcm/bcm_kona_smc.c
>> index a55a7ecf146a..541e850a736c 100644
>> --- a/arch/arm/mach-bcm/bcm_kona_smc.c
>> +++ b/arch/arm/mach-bcm/bcm_kona_smc.c
>> @@ -125,9 +125,7 @@ static int bcm_kona_do_smc(u32 service_id, u32 buffer_phys)
>> __asmeq("%2", "r4")
>> __asmeq("%3", "r5")
>> __asmeq("%4", "r6")
>> -#ifdef REQUIRES_SEC
>> ".arch_extension sec\n"
>> -#endif
>> " smc #0\n"
>> : "=r" (ip), "=r" (r0)
>> : "r" (r4), "r" (r5), "r" (r6)
>
> [...]
>
>> diff --git a/arch/arm/mach-keystone/smc.S b/arch/arm/mach-keystone/smc.S
>> index d15de8179fab..ec03dc499270 100644
>> --- a/arch/arm/mach-keystone/smc.S
>> +++ b/arch/arm/mach-keystone/smc.S
>> @@ -21,6 +21,7 @@
>> *
>> * Return: Non zero value on failure
>> */
>> + .arch_extension sec
>> ENTRY(keystone_cpu_smc)
>> stmfd sp!, {r4-r11, lr}
>> smc #0
>
> [...]
>
>> diff --git a/arch/arm/mach-tango/smc.S b/arch/arm/mach-tango/smc.S
>> index 361a8dc89804..cf2d21e5226c 100644
>> --- a/arch/arm/mach-tango/smc.S
>> +++ b/arch/arm/mach-tango/smc.S
>> @@ -1,6 +1,7 @@
>> /* SPDX-License-Identifier: GPL-2.0 */
>> #include <linux/linkage.h>
>>
>> + .arch_extension sec
>> ENTRY(tango_smc)
>> push {lr}
>> mov ip, r1
>
> Is there some reason these three don't need the .arch directive?

They all do not use a memory barrier instruction (e.g. dmb) which caused
issues on the other files.

--
Stefan

2019-04-10 08:23:54

by Stefan Agner

[permalink] [raw]
Subject: Re: [PATCH v2 1/3] ARM: use arch_extension directive instead of arch argument

On 09.04.2019 14:25, Måns Rullgård wrote:
> Stefan Agner <[email protected]> writes:
>
>> The LLVM Target parser currently does not allow to specify the security
>> extension as part of -march (see also LLVM Bug 40186 [0]). When trying
>> to use Clang with LLVM's integrated assembler, this leads to build
>> errors such as this:
>> clang-8: error: the clang compiler does not support '-Wa,-march=armv7-a+sec'
>>
>> Use ".arch_extension sec" to enable the security extension in a more
>> portable fasion. Also make sure to use ".arch armv7-a" in case a v6/v7
>> multi-platform kernel is being built.
>>
>> Note that this is technically not exactly the same as the old code
>> checked for availabilty of the security extension by calling as-instr.
>> However, there are already other sites which use ".arch_extension sec"
>> unconditionally, hence de-facto we need an assembler capable of
>> ".arch_extension sec" already today (arch/arm/mm/proc-v7.S). The
>> arch extension "sec" is available since binutils 2.21 according to
>> its documentation [1].
>>
>> [0] https://bugs.llvm.org/show_bug.cgi?id=40186
>> [1] https://sourceware.org/binutils/docs-2.21/as/ARM-Options.html
>>
>> Signed-off-by: Stefan Agner <[email protected]>
>> Acked-by: Mans Rullgard <[email protected]>
>> Acked-by: Arnd Bergmann <[email protected]>
>> Acked-by: Krzysztof Kozlowski <[email protected]>
>> ---
>> Changes since v1:
>> - Explicitly specify assembler architecture as armv7-a to avoid
>> build issues when bulding v6/v7 multi arch kernel.
>>
>> arch/arm/mach-bcm/Makefile | 3 ---
>> arch/arm/mach-bcm/bcm_kona_smc.c | 2 --
>> arch/arm/mach-exynos/Makefile | 4 ----
>> arch/arm/mach-exynos/exynos-smc.S | 3 ++-
>> arch/arm/mach-exynos/sleep.S | 3 ++-
>> arch/arm/mach-highbank/Makefile | 3 ---
>> arch/arm/mach-highbank/smc.S | 3 ++-
>> arch/arm/mach-keystone/Makefile | 3 ---
>> arch/arm/mach-keystone/smc.S | 1 +
>> arch/arm/mach-omap2/Makefile | 8 --------
>> arch/arm/mach-omap2/omap-headsmp.S | 2 ++
>> arch/arm/mach-omap2/omap-smc.S | 3 ++-
>> arch/arm/mach-omap2/sleep33xx.S | 1 +
>> arch/arm/mach-omap2/sleep34xx.S | 2 ++
>> arch/arm/mach-omap2/sleep43xx.S | 2 ++
>> arch/arm/mach-omap2/sleep44xx.S | 2 ++
>> arch/arm/mach-tango/Makefile | 3 ---
>> arch/arm/mach-tango/smc.S | 1 +
>> 18 files changed, 19 insertions(+), 30 deletions(-)
>
> [...]
>
>> diff --git a/arch/arm/mach-bcm/bcm_kona_smc.c b/arch/arm/mach-bcm/bcm_kona_smc.c
>> index a55a7ecf146a..541e850a736c 100644
>> --- a/arch/arm/mach-bcm/bcm_kona_smc.c
>> +++ b/arch/arm/mach-bcm/bcm_kona_smc.c
>> @@ -125,9 +125,7 @@ static int bcm_kona_do_smc(u32 service_id, u32 buffer_phys)
>> __asmeq("%2", "r4")
>> __asmeq("%3", "r5")
>> __asmeq("%4", "r6")
>> -#ifdef REQUIRES_SEC
>> ".arch_extension sec\n"
>> -#endif
>> " smc #0\n"
>> : "=r" (ip), "=r" (r0)
>> : "r" (r4), "r" (r5), "r" (r6)
>
> [...]
>
>> diff --git a/arch/arm/mach-keystone/smc.S b/arch/arm/mach-keystone/smc.S
>> index d15de8179fab..ec03dc499270 100644
>> --- a/arch/arm/mach-keystone/smc.S
>> +++ b/arch/arm/mach-keystone/smc.S
>> @@ -21,6 +21,7 @@
>> *
>> * Return: Non zero value on failure
>> */
>> + .arch_extension sec
>> ENTRY(keystone_cpu_smc)
>> stmfd sp!, {r4-r11, lr}
>> smc #0
>
> [...]
>
>> diff --git a/arch/arm/mach-tango/smc.S b/arch/arm/mach-tango/smc.S
>> index 361a8dc89804..cf2d21e5226c 100644
>> --- a/arch/arm/mach-tango/smc.S
>> +++ b/arch/arm/mach-tango/smc.S
>> @@ -1,6 +1,7 @@
>> /* SPDX-License-Identifier: GPL-2.0 */
>> #include <linux/linkage.h>
>>
>> + .arch_extension sec
>> ENTRY(tango_smc)
>> push {lr}
>> mov ip, r1

Actually, mach-tango uses dsb and needs the .arch directive. Will fix in
v3.

--
Stefan

>
> Is there some reason these three don't need the .arch directive?

2019-04-10 10:57:47

by Stefan Agner

[permalink] [raw]
Subject: Re: [PATCH v2 1/3] ARM: use arch_extension directive instead of arch argument

On 09.04.2019 16:50, Tony Lindgren wrote:
> Hi,
>
> * Stefan Agner <[email protected]> [190408 20:59]:
>> --- a/arch/arm/mach-omap2/Makefile
>> +++ b/arch/arm/mach-omap2/Makefile
>> @@ -41,11 +41,6 @@ obj-$(CONFIG_SOC_OMAP5) += $(omap-4-5-common) $(smp-y) sleep44xx.o
>> obj-$(CONFIG_SOC_AM43XX) += $(omap-4-5-common)
>> obj-$(CONFIG_SOC_DRA7XX) += $(omap-4-5-common) $(smp-y) sleep44xx.o
>>
>> -plus_sec := $(call as-instr,.arch_extension sec,+sec)
>> -AFLAGS_omap-headsmp.o :=-Wa,-march=armv7-a$(plus_sec)
>> -AFLAGS_omap-smc.o :=-Wa,-march=armv7-a$(plus_sec)
>> -AFLAGS_sleep44xx.o :=-Wa,-march=armv7-a$(plus_sec)
>> -
>> # Functions loaded to SRAM
>> obj-$(CONFIG_SOC_OMAP2420) += sram242x.o
>> obj-$(CONFIG_SOC_OMAP2430) += sram243x.o
>> @@ -95,9 +90,6 @@ obj-$(CONFIG_POWER_AVS_OMAP) += sr_device.o
>> obj-$(CONFIG_POWER_AVS_OMAP_CLASS3) += smartreflex-class3.o
>>
>> AFLAGS_sleep24xx.o :=-Wa,-march=armv6
>> -AFLAGS_sleep34xx.o :=-Wa,-march=armv7-a$(plus_sec)
>> -AFLAGS_sleep33xx.o :=-Wa,-march=armv7-a$(plus_sec)
>> -AFLAGS_sleep43xx.o :=-Wa,-march=armv7-a$(plus_sec)
>
> I think we should also change the AFLAGS_sleep24xx.o above the
> same way but with armv6 flags. This can be build tested with
> omap2plus_defconfig.

From what I can tell, since those do not add the sec extension they
should work fine for LLVM's integrated assembler. But I agree, for
consistency it would be nice to get rid of them the same way too.

A bit further up, there is also:
AFLAGS_sram242x.o :=-Wa,-march=armv6
AFLAGS_sram243x.o :=-Wa,-march=armv6

I think those explicit arch definitions are not even necessary since
ARCH_OMAP2 depends on ARCH_MULTI_V6, which cannot be built with pre v6
architecture. So the minimum architecture we build for will be armv6...

In a quick test omap2plus_defconfig builds fine without those AFLAGS. I
will put it through some more testing and drop those flags in v3.

--
Stefan


>
> Regards,
>
> Tony