Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755335AbaDUVxv (ORCPT ); Mon, 21 Apr 2014 17:53:51 -0400 Received: from mail-yk0-f171.google.com ([209.85.160.171]:62503 "EHLO mail-yk0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755272AbaDUVxi (ORCPT ); Mon, 21 Apr 2014 17:53:38 -0400 From: Alex Elder To: bcm@fixthebug.org, mporter@linaro.org Cc: bcm-kernel-feedback-list@broadcom.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 08/10] ARM: bcm: use inline assembly for "smc" request Date: Mon, 21 Apr 2014 16:53:09 -0500 Message-Id: <1398117191-2433-9-git-send-email-elder@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1398117191-2433-1-git-send-email-elder@linaro.org> References: <1398117191-2433-1-git-send-email-elder@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Move the code that implements the "smc" call into a C function that uses inline assembly. This allows us to make that function private, and enables us to get rid of "arch/arm/mach-bcm/bcm_kona_smc_asm.S". Rename what had been the "buffer_addr" argument to be "buffer_phys" so it's consistent with other usage in this file. Since it's now easy to do, verify that r12 contains SEC_EXIT_NORMAL upon completion of the SMC. There really isn't a good way to handle the abnormal completion of a secure monitor request. Since "bcm_kona_smc.h" is now only included from C files, eliminate the #ifndef __ASSEMBLY__. Signed-off-by: Alex Elder Reviewed-by: Tim Kryger Reviewed-by: Markus Mayer Reviewed-by: Matt Porter --- arch/arm/mach-bcm/Makefile | 7 +++--- arch/arm/mach-bcm/bcm_kona_smc.c | 46 +++++++++++++++++++++++++++++++++++- arch/arm/mach-bcm/bcm_kona_smc.h | 6 ----- arch/arm/mach-bcm/bcm_kona_smc_asm.S | 41 -------------------------------- 4 files changed, 49 insertions(+), 51 deletions(-) delete mode 100644 arch/arm/mach-bcm/bcm_kona_smc_asm.S diff --git a/arch/arm/mach-bcm/Makefile b/arch/arm/mach-bcm/Makefile index 5154981..d5b60fe 100644 --- a/arch/arm/mach-bcm/Makefile +++ b/arch/arm/mach-bcm/Makefile @@ -20,9 +20,10 @@ obj-$(CONFIG_ARCH_BCM_21664) += board_bcm21664.o obj-$(CONFIG_ARCH_BCM_MOBILE_L2_CACHE) += kona.o # Support for secure monitor traps -obj-$(CONFIG_ARCH_BCM_MOBILE_SMC) += bcm_kona_smc.o bcm_kona_smc_asm.o -plus_sec := $(call as-instr,.arch_extension sec,+sec) -AFLAGS_bcm_kona_smc_asm.o :=-Wa,-march=armv7-a$(plus_sec) +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 6fdcf96..cc81c86 100644 --- a/arch/arm/mach-bcm/bcm_kona_smc.c +++ b/arch/arm/mach-bcm/bcm_kona_smc.c @@ -76,6 +76,50 @@ int __init bcm_kona_smc_init(void) return 0; } +/* + * Since interrupts are disabled in the open mode, we must keep + * interrupts disabled in secure mode by setting R5=0x3. If interrupts + * are enabled in open mode, we can set R5=0x0 to allow interrupts in + * secure mode. If we did this, the secure monitor would return back + * control to the open mode to handle the interrupt prior to completing + * the secure service. If this happened, R12 would not be + * SEC_EXIT_NORMAL and we would need to call SMC again after resetting + * R5 (it gets clobbered by the secure monitor) and setting R4 to + * SSAPI_RET_FROM_INT_SERV to indicate that we want the secure monitor + * to finish up the previous uncompleted secure service. + */ +static int bcm_kona_do_smc(u32 service_id, u32 buffer_phys) +{ + register u32 ip asm("ip"); /* Also called r12 */ + register u32 r0 asm("r0"); + register u32 r4 asm("r4"); + register u32 r5 asm("r5"); + register u32 r6 asm("r6"); + + r4 = service_id; + r5 = 0x3; /* Keep IRQ and FIQ off in SM */ + r6 = buffer_phys; + + asm volatile ( + /* Make sure we got the registers we want */ + __asmeq("%0", "ip") + __asmeq("%1", "r0") + __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) + : "r1", "r2", "r3", "r7", "lr"); + + BUG_ON(ip != SEC_EXIT_NORMAL); + + return r0; +} + /* __bcm_kona_smc() should only run on CPU 0, with pre-emption disabled */ static void __bcm_kona_smc(void *info) { @@ -95,7 +139,7 @@ static void __bcm_kona_smc(void *info) flush_cache_all(); /* Trap into Secure Monitor and record the request result */ - data->result = bcm_kona_smc_asm(data->service_id, bcm_smc_buffer_phys); + data->result = bcm_kona_do_smc(data->service_id, bcm_smc_buffer_phys); } unsigned bcm_kona_smc(unsigned service_id, unsigned arg0, unsigned arg1, diff --git a/arch/arm/mach-bcm/bcm_kona_smc.h b/arch/arm/mach-bcm/bcm_kona_smc.h index 629e64a..2e29ec6 100644 --- a/arch/arm/mach-bcm/bcm_kona_smc.h +++ b/arch/arm/mach-bcm/bcm_kona_smc.h @@ -21,7 +21,6 @@ #define SEC_ROM_RET_OK 0x00000001 #define SEC_EXIT_NORMAL 0x1 -#ifndef __ASSEMBLY__ extern int __init bcm_kona_smc_init(void); extern unsigned bcm_kona_smc(unsigned service_id, @@ -30,9 +29,4 @@ extern unsigned bcm_kona_smc(unsigned service_id, unsigned arg2, unsigned arg3); -extern int bcm_kona_smc_asm(u32 service_id, - u32 buffer_addr); - -#endif /* __ASSEMBLY__ */ - #endif /* BCM_KONA_SMC_H */ diff --git a/arch/arm/mach-bcm/bcm_kona_smc_asm.S b/arch/arm/mach-bcm/bcm_kona_smc_asm.S deleted file mode 100644 index a160848..0000000 --- a/arch/arm/mach-bcm/bcm_kona_smc_asm.S +++ /dev/null @@ -1,41 +0,0 @@ -/* - * Copyright (C) 2013 Broadcom Corporation - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License as - * published by the Free Software Foundation version 2. - * - * This program is distributed "as is" WITHOUT ANY WARRANTY of any - * kind, whether express or implied; without even the implied warranty - * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - */ - -#include -#include "bcm_kona_smc.h" - -/* - * int bcm_kona_smc_asm(u32 service_id, u32 buffer_addr) - */ - -ENTRY(bcm_kona_smc_asm) - stmfd sp!, {r4-r12, lr} - mov r4, r0 @ service_id - mov r5, #3 @ Keep IRQ and FIQ off in SM - /* - * Since interrupts are disabled in the open mode, we must keep - * interrupts disabled in secure mode by setting R5=0x3. If interrupts - * are enabled in open mode, we can set R5=0x0 to allow interrupts in - * secure mode. If we did this, the secure monitor would return back - * control to the open mode to handle the interrupt prior to completing - * the secure service. If this happened, R12 would not be - * SEC_EXIT_NORMAL and we would need to call SMC again after resetting - * R5 (it gets clobbered by the secure monitor) and setting R4 to - * SSAPI_RET_FROM_INT_SERV to indicate that we want the secure monitor - * to finish up the previous uncompleted secure service. - */ - mov r6, r1 @ buffer_addr - smc #0 - /* Check r12 for SEC_EXIT_NORMAL here if interrupts are enabled */ - ldmfd sp!, {r4-r12, pc} -ENDPROC(bcm_kona_smc_asm) -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/