arm: omap-common: add secure smc entry

Add an interface for calling secure ROM APIs across a range of OMAP and
OMAP compatible high-security (HS) device variants. While at it, also
perform minor cleanup/alignment without any change in functionality.

Signed-off-by: Daniel Allred <d-allred@ti.com>
Signed-off-by: Andreas Dannenberg <dannenberg@ti.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>

arch/arm/cpu/armv7/omap-common/lowlevel_init.S

@@ -16,24 +16,51 @@
 #include <asm/arch/spl.h>
 #include <linux/linkage.h>
 
+.arch_extension sec
+
 #ifdef CONFIG_SPL
 ENTRY(save_boot_params)
-
 	ldr	r1, =OMAP_SRAM_SCRATCH_BOOT_PARAMS
 	str	r0, [r1]
 	b	save_boot_params_ret
 ENDPROC(save_boot_params)
 #endif
 
 ENTRY(omap_smc1)
-	PUSH	{r4-r12, lr}	@ save registers - ROM code may pollute
+	push	{r4-r12, lr}	@ save registers - ROM code may pollute
 				@ our registers
-	MOV	r12, r0		@ Service
-	MOV	r0, r1		@ Argument
-	DSB
-	DMB
-	.word	0xe1600070	@ SMC #0 - hand assembled for GCC versions
-				@ call ROM Code API for the service requested
+	mov	r12, r0		@ Service
+	mov	r0, r1		@ Argument
 
-	POP	{r4-r12, pc}
+	dsb
+	dmb
+	smc	0		@ SMC #0 to enter monitor mode
+				@ call ROM Code API for the service requested
+	pop	{r4-r12, pc}
 ENDPROC(omap_smc1)
+
+ENTRY(omap_smc_sec)
+	push	{r4-r12, lr}	@ save registers - ROM code may pollute
+				@ our registers
+	mov	r6, #0xFF	@ Indicate new Task call
+	mov	r12, #0x00	@ Secure Service ID in R12
+
+	dsb
+	dmb
+	smc	0		@ SMC #0 to enter monitor mode
+
+	b	omap_smc_sec_end @ exit at end of the service execution
+	nop
+
+	@ In case of IRQ happening in Secure, then ARM will branch here.
+	@ At that moment, IRQ will be pending and ARM will jump to Non Secure
+	@ IRQ handler
+	mov	r12, #0xFE
+
+	dsb
+	dmb
+	smc	0		@ SMC #0 to enter monitor mode
+
+omap_smc_sec_end:
+	pop	{r4-r12, pc}
+ENDPROC(omap_smc_sec)

arch/arm/include/asm/omap_common.h

@@ -627,6 +627,12 @@ void recalibrate_iodelay(void);
 
 void omap_smc1(u32 service, u32 val);
 
+/*
+ * Low-level helper function used when performing secure ROM calls on high-
+ * security (HS) device variants by doing a specially-formed smc entry.
+ */
+u32 omap_smc_sec(u32 service, u32 proc_id, u32 flag, u32 *params);
+
 void enable_edma3_clocks(void);
 void disable_edma3_clocks(void);