From mboxrd@z Thu Jan 1 00:00:00 1970 From: dannenberg@ti.com (Andreas Dannenberg) Date: Wed, 2 Mar 2016 15:26:28 -0600 Subject: [v8,2/4] arm: add implementation for arm-smccc In-Reply-To: <1451912079-29258-3-git-send-email-jens.wiklander@linaro.org> References: <1451912079-29258-3-git-send-email-jens.wiklander@linaro.org> Message-ID: <20160302212628.GA12740@borg.dal.design.ti.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 > Signed-off-by: Jens Wiklander > > --- > 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 > #include > #include > +#include > > #include > #include > @@ -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 > + > +#include > +#include > +#include > + > + /* > + * 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)