ARM: 8264/1: EXYNOS: Add support for non-secure L2X0 resume

On Exynos SoCs it is necessary to resume operation of L2C early in
assembly code, because otherwise certain systems will crash. This patch
adds necessary code to non-secure resume handler.

[rewrote the code accessing l2x0_saved_regs]
Signed-off-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mach-exynos/sleep.S

@@ -16,6 +16,8 @@
  */
 
 #include <linux/linkage.h>
+#include <asm/asm-offsets.h>
+#include <asm/hardware/cache-l2x0.h>
 #include "smc.h"
 
 #define CPU_MASK	0xff0ffff0
@@ -74,6 +76,45 @@ ENTRY(exynos_cpu_resume_ns)
 	mov	r0, #SMC_CMD_C15RESUME
 	dsb
 	smc	#0
+#ifdef CONFIG_CACHE_L2X0
+	adr	r0, 1f
+	ldr	r2, [r0]
+	add	r0, r2, r0
+
+	/* Check that the address has been initialised. */
+	ldr	r1, [r0, #L2X0_R_PHY_BASE]
+	teq	r1, #0
+	beq	skip_l2x0
+
+	/* Check if controller has been enabled. */
+	ldr	r2, [r1, #L2X0_CTRL]
+	tst	r2, #0x1
+	bne	skip_l2x0
+
+	ldr	r1, [r0, #L2X0_R_TAG_LATENCY]
+	ldr	r2, [r0, #L2X0_R_DATA_LATENCY]
+	ldr	r3, [r0, #L2X0_R_PREFETCH_CTRL]
+	mov	r0, #SMC_CMD_L2X0SETUP1
+	smc	#0
+
+	/* Reload saved regs pointer because smc corrupts registers. */
+	adr	r0, 1f
+	ldr	r2, [r0]
+	add	r0, r2, r0
+
+	ldr	r1, [r0, #L2X0_R_PWR_CTRL]
+	ldr	r2, [r0, #L2X0_R_AUX_CTRL]
+	mov	r0, #SMC_CMD_L2X0SETUP2
+	smc	#0
+
+	mov	r0, #SMC_CMD_L2X0INVALL
+	smc	#0
+
+	mov	r1, #1
+	mov	r0, #SMC_CMD_L2X0CTRL
+	smc	#0
+skip_l2x0:
+#endif /* CONFIG_CACHE_L2X0 */
 skip_cp15:
 	b	cpu_resume
 ENDPROC(exynos_cpu_resume_ns)
@@ -83,3 +124,8 @@ cp15_save_diag:
 	.globl cp15_save_power
 cp15_save_power:
 	.long	0	@ cp15 power control
+
+#ifdef CONFIG_CACHE_L2X0
+	.align
+1:	.long	l2x0_saved_regs - .
+#endif /* CONFIG_CACHE_L2X0 */