[PATCH v2 08/10] ARM: bcm: use inline assembly for "smc" request
Alex Elder
elder at linaro.org
Mon Apr 21 14:53:09 PDT 2014
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 <elder at linaro.org>
Reviewed-by: Tim Kryger <tim.kryger at linaro.org>
Reviewed-by: Markus Mayer <markus.mayer at linaro.org>
Reviewed-by: Matt Porter <mporter at linaro.org>
---
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 <linux/linkage.h>
-#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
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