ARM: OMAP2+: Use ARM SMC Calling Convention when OP-TEE is available

On High-Security(HS) OMAP2+ class devices a couple actions must be
performed from the ARM TrustZone during boot. These traditionally can be
performed by calling into the secure ROM code resident in this secure
world using legacy SMC calls. Optionally OP-TEE can replace this secure
world functionality by replacing the ROM after boot. ARM recommends a
standard calling convention is used for this interaction (SMC Calling
Convention). We check for the presence of OP-TEE and use this type of
call to perform the needed actions, falling back to the legacy OMAP ROM
call if OP-TEE is not available.

Signed-off-by: Andrew F. Davis <afd@ti.com>
Reviewed-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

diff --git a/arch/arm/mach-omap2/common.h b/arch/arm/mach-omap2/common.h
index 223b37c4838934e033080f387ed324bdec8bbd37..3b1fd8e7d70542f14fa7d3555bf4de37a5450b67 100644 (file)
--- a/arch/arm/mach-omap2/common.h
+++ b/arch/arm/mach-omap2/common.h
@@ -255,7 +255,7 @@ extern void gic_dist_disable(void);
 extern void gic_dist_enable(void);
 extern bool gic_dist_disabled(void);
 extern void gic_timer_retrigger(void);
-extern void omap_smc1(u32 fn, u32 arg);
+extern void _omap_smc1(u32 fn, u32 arg);
 extern void omap4_sar_ram_init(void);
 extern void __iomem *omap4_get_sar_ram_base(void);
 extern void omap4_mpuss_early_init(void);

diff --git a/arch/arm/mach-omap2/omap-secure.c b/arch/arm/mach-omap2/omap-secure.c
index 5686466600810b7526e98462355cf09f825f6209..d00e3c72e37dd2db48324ad82a8f182a158e554b 100644 (file)
--- a/arch/arm/mach-omap2/omap-secure.c
+++ b/arch/arm/mach-omap2/omap-secure.c
@@ -8,6 +8,7 @@
  * Copyright (C) 2013 Pali Rohár <pali.rohar@gmail.com>
  */
 
+#include <linux/arm-smccc.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/io.h>
@@ -17,12 +18,17 @@
 #include <asm/cacheflush.h>
 #include <asm/memblock.h>
 
+#include "common.h"
 #include "omap-secure.h"
 
 static phys_addr_t omap_secure_memblock_base;
 
 bool optee_available;
 
+#define OMAP_SIP_SMC_STD_CALL_VAL(func_num) \
+       ARM_SMCCC_CALL_VAL(ARM_SMCCC_STD_CALL, ARM_SMCCC_SMC_32, \
+       ARM_SMCCC_OWNER_SIP, (func_num))
+
 static void __init omap_optee_init_check(void)
 {
        struct device_node *np;
@@ -71,6 +77,27 @@ u32 omap_secure_dispatcher(u32 idx, u32 flag, u32 nargs, u32 arg1, u32 arg2,
        return ret;
 }
 
+void omap_smccc_smc(u32 fn, u32 arg)
+{
+       struct arm_smccc_res res;
+
+       arm_smccc_smc(OMAP_SIP_SMC_STD_CALL_VAL(fn), arg,
+                     0, 0, 0, 0, 0, 0, &res);
+       WARN(res.a0, "Secure function call 0x%08x failed\n", fn);
+}
+
+void omap_smc1(u32 fn, u32 arg)
+{
+       /*
+        * If this platform has OP-TEE installed we use ARM SMC calls
+        * otherwise fall back to the OMAP ROM style calls.
+        */
+       if (optee_available)
+               omap_smccc_smc(fn, arg);
+       else
+               _omap_smc1(fn, arg);
+}
+
 /* Allocate the memory to save secure ram */
 int __init omap_secure_ram_reserve_memblock(void)
 {

diff --git a/arch/arm/mach-omap2/omap-secure.h b/arch/arm/mach-omap2/omap-secure.h
index 78a1c4f04bbe0110ff80bd8c94d487112dcf009b..736e594365f4d5459ae22e985ba11c5bb8016328 100644 (file)
--- a/arch/arm/mach-omap2/omap-secure.h
+++ b/arch/arm/mach-omap2/omap-secure.h
@@ -62,6 +62,8 @@
 
 extern u32 omap_secure_dispatcher(u32 idx, u32 flag, u32 nargs,
                                u32 arg1, u32 arg2, u32 arg3, u32 arg4);
+extern void omap_smccc_smc(u32 fn, u32 arg);
+extern void omap_smc1(u32 fn, u32 arg);
 extern u32 omap_smc2(u32 id, u32 falg, u32 pargs);
 extern u32 omap_smc3(u32 id, u32 process, u32 flag, u32 pargs);
 extern phys_addr_t omap_secure_ram_mempool_base(void);

diff --git a/arch/arm/mach-omap2/omap-smc.S b/arch/arm/mach-omap2/omap-smc.S
index fd2bcd91f4a14c874bd8b833bd91a7e5ef0d8c8c..d4832845a4e8b7faba9cc4af09927dcab6dc61d4 100644 (file)
--- a/arch/arm/mach-omap2/omap-smc.S
+++ b/arch/arm/mach-omap2/omap-smc.S
@@ -18,18 +18,18 @@
  * the monitor API number. It uses few CPU registers
  * internally and hence they need be backed up including
  * link register "lr".
- * Function signature : void omap_smc1(u32 fn, u32 arg)
+ * Function signature : void _omap_smc1(u32 fn, u32 arg)
  */
        .arch armv7-a
        .arch_extension sec
-ENTRY(omap_smc1)
+ENTRY(_omap_smc1)
        stmfd   sp!, {r2-r12, lr}
        mov     r12, r0
        mov     r0, r1
        dsb
        smc     #0
        ldmfd   sp!, {r2-r12, pc}
-ENDPROC(omap_smc1)
+ENDPROC(_omap_smc1)
 
 /**
  * u32 omap_smc2(u32 id, u32 falg, u32 pargs)