| Message ID | 1451912079-29258-3-git-send-email-jens.wiklander@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Jan 04, 2016 at 01:54:37PM +0100, Jens Wiklander wrote: > Adds implementation for arm-smccc and enables CONFIG_HAVE_SMCCC for > architectures that may support arm-smccc. It's the responsibility of the > caller to know if the SMC instruction is supported by the platform. > > Reviewed-by: Lars Persson <lars.persson@axis.com> > Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org> > > --- > arch/arm/Kconfig | 1 + > arch/arm/kernel/Makefile | 2 ++ > arch/arm/kernel/armksyms.c | 6 +++++ > arch/arm/kernel/smccc-call.S | 62 ++++++++++++++++++++++++++++++++++++++++++++ > 4 files changed, 71 insertions(+) > create mode 100644 arch/arm/kernel/smccc-call.S > > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > index 34e1569..36b9490 100644 > --- a/arch/arm/Kconfig > +++ b/arch/arm/Kconfig > @@ -37,6 +37,7 @@ config ARM > select HAVE_ARCH_KGDB if !CPU_ENDIAN_BE32 > select HAVE_ARCH_SECCOMP_FILTER if (AEABI && !OABI_COMPAT) > select HAVE_ARCH_TRACEHOOK > + select HAVE_ARM_SMCCC if CPU_V7 > select HAVE_BPF_JIT > select HAVE_CC_STACKPROTECTOR > select HAVE_CONTEXT_TRACKING > diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile > index af9e59b..d2d0042 100644 > --- a/arch/arm/kernel/Makefile > +++ b/arch/arm/kernel/Makefile > @@ -92,4 +92,6 @@ obj-y += psci-call.o > obj-$(CONFIG_SMP) += psci_smp.o > endif > > +obj-$(CONFIG_HAVE_ARM_SMCCC) += smccc-call.o > + > extra-y := $(head-y) vmlinux.lds > diff --git a/arch/arm/kernel/armksyms.c b/arch/arm/kernel/armksyms.c > index f89811f..7e45f69 100644 > --- a/arch/arm/kernel/armksyms.c > +++ b/arch/arm/kernel/armksyms.c > @@ -16,6 +16,7 @@ > #include <linux/syscalls.h> > #include <linux/uaccess.h> > #include <linux/io.h> > +#include <linux/arm-smccc.h> > > #include <asm/checksum.h> > #include <asm/ftrace.h> > @@ -175,3 +176,8 @@ EXPORT_SYMBOL(__gnu_mcount_nc); > EXPORT_SYMBOL(__pv_phys_pfn_offset); > EXPORT_SYMBOL(__pv_offset); > #endif > + > +#ifdef CONFIG_HAVE_ARM_SMCCC > +EXPORT_SYMBOL(arm_smccc_smc); > +EXPORT_SYMBOL(arm_smccc_hvc); > +#endif > diff --git a/arch/arm/kernel/smccc-call.S b/arch/arm/kernel/smccc-call.S > new file mode 100644 > index 0000000..2e48b67 > --- /dev/null > +++ b/arch/arm/kernel/smccc-call.S > @@ -0,0 +1,62 @@ > +/* > + * Copyright (c) 2015, Linaro Limited > + * > + * This software is licensed under the terms of the GNU General Public > + * License version 2, as published by the Free Software Foundation, and > + * may be copied, distributed, and modified under those terms. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + * > + */ > +#include <linux/linkage.h> > + > +#include <asm/opcodes-sec.h> > +#include <asm/opcodes-virt.h> > +#include <asm/unwind.h> > + > + /* > + * Wrap c macros in asm macros to delay expansion until after the > + * SMCCC asm macro is expanded. > + */ > + .macro SMCCC_SMC > + __SMC(0) > + .endm > + > + .macro SMCCC_HVC > + __HVC(0) > + .endm > + > + .macro SMCCC instr > +UNWIND( .fnstart) > + mov r12, sp > + push {r4-r7} > +UNWIND( .save {r4-r7}) > + ldm r12, {r4-r7} > + \instr Jens, out of curiosity, we don't need any dsb/dmb calls here? I've rummaged through some other code here at TI and see such barriers being included right before the smc call. However in all fairness I also don't see such memory calls included in arch/arm/kernel/psci-call.S that your other patch is removing, so either they are really not needed or I didn't look right and need to go to have my prescriptions checked. Regards, -- Andreas Dannenberg Texas Instruments Inc > + pop {r4-r7} > + ldr r12, [sp, #(4 * 4)] > + stm r12, {r0-r3} > + bx lr > +UNWIND( .fnend) > + .endm > + > +/* > + * void smccc_smc(unsigned long a0, unsigned long a1, unsigned long a2, > + * unsigned long a3, unsigned long a4, unsigned long a5, > + * unsigned long a6, unsigned long a7, struct arm_smccc_res *res) > + */ > +ENTRY(arm_smccc_smc) > + SMCCC SMCCC_SMC > +ENDPROC(arm_smccc_smc) > + > +/* > + * void smccc_hvc(unsigned long a0, unsigned long a1, unsigned long a2, > + * unsigned long a3, unsigned long a4, unsigned long a5, > + * unsigned long a6, unsigned long a7, struct arm_smccc_res *res) > + */ > +ENTRY(arm_smccc_hvc) > + SMCCC SMCCC_HVC > +ENDPROC(arm_smccc_hvc)
On Wed, Mar 02, 2016 at 03:26:28PM -0600, Andreas Dannenberg wrote: > On Mon, Jan 04, 2016 at 01:54:37PM +0100, Jens Wiklander wrote: > > diff --git a/arch/arm/kernel/smccc-call.S b/arch/arm/kernel/smccc-call.S > > new file mode 100644 > > index 0000000..2e48b67 > > --- /dev/null > > +++ b/arch/arm/kernel/smccc-call.S > > @@ -0,0 +1,62 @@ > > +/* > > + * Copyright (c) 2015, Linaro Limited > > + * > > + * This software is licensed under the terms of the GNU General Public > > + * License version 2, as published by the Free Software Foundation, and > > + * may be copied, distributed, and modified under those terms. > > + * > > + * This program is distributed in the hope that it will be useful, > > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > > + * GNU General Public License for more details. > > + * > > + */ > > +#include <linux/linkage.h> > > + > > +#include <asm/opcodes-sec.h> > > +#include <asm/opcodes-virt.h> > > +#include <asm/unwind.h> > > + > > + /* > > + * Wrap c macros in asm macros to delay expansion until after the > > + * SMCCC asm macro is expanded. > > + */ > > + .macro SMCCC_SMC > > + __SMC(0) > > + .endm > > + > > + .macro SMCCC_HVC > > + __HVC(0) > > + .endm > > + > > + .macro SMCCC instr > > +UNWIND( .fnstart) > > + mov r12, sp > > + push {r4-r7} > > +UNWIND( .save {r4-r7}) > > + ldm r12, {r4-r7} > > + \instr > > Jens, > out of curiosity, we don't need any dsb/dmb calls here? I've rummaged > through some other code here at TI and see such barriers being included > right before the smc call. However in all fairness I also don't see such > memory calls included in arch/arm/kernel/psci-call.S that your other > patch is removing, so either they are really not needed or I didn't look > right and need to go to have my prescriptions checked. There are no architectural requirements for a barrier here. My understanding of the TI code is that it was there to work around buggy firmware. Will
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 34e1569..36b9490 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -37,6 +37,7 @@ config ARM select HAVE_ARCH_KGDB if !CPU_ENDIAN_BE32 select HAVE_ARCH_SECCOMP_FILTER if (AEABI && !OABI_COMPAT) select HAVE_ARCH_TRACEHOOK + select HAVE_ARM_SMCCC if CPU_V7 select HAVE_BPF_JIT select HAVE_CC_STACKPROTECTOR select HAVE_CONTEXT_TRACKING diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile index af9e59b..d2d0042 100644 --- a/arch/arm/kernel/Makefile +++ b/arch/arm/kernel/Makefile @@ -92,4 +92,6 @@ obj-y += psci-call.o obj-$(CONFIG_SMP) += psci_smp.o endif +obj-$(CONFIG_HAVE_ARM_SMCCC) += smccc-call.o + extra-y := $(head-y) vmlinux.lds diff --git a/arch/arm/kernel/armksyms.c b/arch/arm/kernel/armksyms.c index f89811f..7e45f69 100644 --- a/arch/arm/kernel/armksyms.c +++ b/arch/arm/kernel/armksyms.c @@ -16,6 +16,7 @@ #include <linux/syscalls.h> #include <linux/uaccess.h> #include <linux/io.h> +#include <linux/arm-smccc.h> #include <asm/checksum.h> #include <asm/ftrace.h> @@ -175,3 +176,8 @@ EXPORT_SYMBOL(__gnu_mcount_nc); EXPORT_SYMBOL(__pv_phys_pfn_offset); EXPORT_SYMBOL(__pv_offset); #endif + +#ifdef CONFIG_HAVE_ARM_SMCCC +EXPORT_SYMBOL(arm_smccc_smc); +EXPORT_SYMBOL(arm_smccc_hvc); +#endif diff --git a/arch/arm/kernel/smccc-call.S b/arch/arm/kernel/smccc-call.S new file mode 100644 index 0000000..2e48b67 --- /dev/null +++ b/arch/arm/kernel/smccc-call.S @@ -0,0 +1,62 @@ +/* + * Copyright (c) 2015, Linaro Limited + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + */ +#include <linux/linkage.h> + +#include <asm/opcodes-sec.h> +#include <asm/opcodes-virt.h> +#include <asm/unwind.h> + + /* + * Wrap c macros in asm macros to delay expansion until after the + * SMCCC asm macro is expanded. + */ + .macro SMCCC_SMC + __SMC(0) + .endm + + .macro SMCCC_HVC + __HVC(0) + .endm + + .macro SMCCC instr +UNWIND( .fnstart) + mov r12, sp + push {r4-r7} +UNWIND( .save {r4-r7}) + ldm r12, {r4-r7} + \instr + pop {r4-r7} + ldr r12, [sp, #(4 * 4)] + stm r12, {r0-r3} + bx lr +UNWIND( .fnend) + .endm + +/* + * void smccc_smc(unsigned long a0, unsigned long a1, unsigned long a2, + * unsigned long a3, unsigned long a4, unsigned long a5, + * unsigned long a6, unsigned long a7, struct arm_smccc_res *res) + */ +ENTRY(arm_smccc_smc) + SMCCC SMCCC_SMC +ENDPROC(arm_smccc_smc) + +/* + * void smccc_hvc(unsigned long a0, unsigned long a1, unsigned long a2, + * unsigned long a3, unsigned long a4, unsigned long a5, + * unsigned long a6, unsigned long a7, struct arm_smccc_res *res) + */ +ENTRY(arm_smccc_hvc) + SMCCC SMCCC_HVC +ENDPROC(arm_smccc_hvc)