Exynos542x: CPU: Power down all secondary cores

This patch adds code to shutdown secondary cores.
When U-boot comes up, all secondary cores appear powered on,
which is undesirable and causes side effects while
initializing these cores in kernel.

Secondary core power down happens in following steps:

Step-1: After Exynos power-on, primary core starts executing first.
Step-2: In iROM code every core has to check 2 flags i.e.
	addresses 0x02020028 & 0x02020004.
Step-3: Initially 0x02020028 is 0 for all cores and 0x02020004 has a
	jump address for primary core and 0 for all secondary cores.
Step-4: Therefore, primary core follows normal iROM execution and jumps
	to BL1 eventually, whereas all secondary cores enter WFE.
Step-5: When primary core comes into function secondary_cores_configure,
	it puts pointer to function power_down_core into 0x02020004
	and provides DSB and SEV for all cores so that they may come out
	of WFE and jump to power_down_core function.
Step-6: And ultimately because of power_down_core all
	secondary cores shut-down.

Signed-off-by: Kimoon Kim <kimoon.kim@samsung.com>
Signed-off-by: Akshay Saraswat <akshay.s@samsung.com>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>

2 files changed, 92 insertions, 0 deletions

diff --git a/arch/arm/include/asm/arch-exynos/cpu.h b/arch/arm/include/asm/arch-exynos/cpu.h
index 29674ad4da..e7395201ad 100644
--- a/arch/arm/include/asm/arch-exynos/cpu.h
+++ b/arch/arm/include/asm/arch-exynos/cpu.h
@@ -153,6 +153,10 @@
 #define EXYNOS5420_CLOCK_BASE		0x10010000
 #define EXYNOS5420_POWER_BASE		0x10040000
 #define EXYNOS5420_SWRESET		0x10040400
+#define EXYNOS5420_INFORM_BASE		0x10040800
+#define EXYNOS5420_SPARE_BASE		0x10040900
+#define EXYNOS5420_CPU_CONFIG_BASE	0x10042000
+#define EXYNOS5420_CPU_STATUS_BASE	0x10042004
 #define EXYNOS5420_SYSREG_BASE		0x10050000
 #define EXYNOS5420_TZPC_BASE		0x100E0000
 #define EXYNOS5420_WATCHDOG_BASE	0x101D0000
@@ -186,6 +190,7 @@
 #define EXYNOS5420_USB3PHY_BASE		DEVICE_NOT_AVAILABLE
 #define EXYNOS5420_USB_HOST_XHCI_BASE	DEVICE_NOT_AVAILABLE
 
+
 #ifndef __ASSEMBLY__
 #include <asm/io.h>
 /* CPU detection macros */
diff --git a/arch/arm/include/asm/arch-exynos/system.h b/arch/arm/include/asm/arch-exynos/system.h
index 4968d3dd2e..86903c3696 100644
--- a/arch/arm/include/asm/arch-exynos/system.h
+++ b/arch/arm/include/asm/arch-exynos/system.h
@@ -37,6 +37,93 @@ struct exynos5_sysreg {
 
 #define USB20_PHY_CFG_HOST_LINK_EN	(1 << 0)
 
+#ifdef CONFIG_EXYNOS5420
+/*
+ * Data Synchronization Barrier acts as a special kind of memory barrier.
+ * No instruction in program order after this instruction executes until
+ * this instruction completes. This instruction completes when:
+ * - All explicit memory accesses before this instruction complete.
+ * - All Cache, Branch predictor and TLB maintenance operations before
+ *   this instruction complete.
+ */
+#define dsb() __asm__ __volatile__ ("dsb\n\t" : : );
+
+/*
+ * This instruction causes an event to be signaled to all cores
+ * within a multiprocessor system. If SEV is implemented,
+ * WFE must also be implemented.
+ */
+#define sev() __asm__ __volatile__ ("sev\n\t" : : );
+/*
+ * If the Event Register is not set, WFE suspends execution until
+ * one of the following events occurs:
+ * - an IRQ interrupt, unless masked by the CPSR I-bit
+ * - an FIQ interrupt, unless masked by the CPSR F-bit
+ * - an Imprecise Data abort, unless masked by the CPSR A-bit
+ * - a Debug Entry request, if Debug is enabled
+ * - an Event signaled by another processor using the SEV instruction.
+ * If the Event Register is set, WFE clears it and returns immediately.
+ * If WFE is implemented, SEV must also be implemented.
+ */
+#define wfe() __asm__ __volatile__ ("wfe\n\t" : : );
+
+/* Move 0xd3 value to CPSR register to enable SVC mode */
+#define svc32_mode_en() __asm__ __volatile__				\
+			("@ I&F disable, Mode: 0x13 - SVC\n\t"		\
+			 "msr     cpsr_c, #0x13|0xC0\n\t" : : )
+
+/* Set program counter with the given value */
+#define set_pc(x) __asm__ __volatile__ ("mov     pc, %0\n\t" : : "r"(x))
+
+/* Read Main Id register */
+#define mrc_midr(x) __asm__ __volatile__	\
+			("mrc     p15, 0, %0, c0, c0, 0\n\t" : "=r"(x) : )
+
+/* Read Multiprocessor Affinity Register */
+#define mrc_mpafr(x) __asm__ __volatile__	\
+			("mrc     p15, 0, %0, c0, c0, 5\n\t" : "=r"(x) : )
+
+/* Read System Control Register */
+#define mrc_sctlr(x) __asm__ __volatile__	\
+			("mrc     p15, 0, %0, c1, c0, 0\n\t" : "=r"(x) : )
+
+/* Read Auxiliary Control Register */
+#define mrc_auxr(x) __asm__ __volatile__	\
+			("mrc     p15, 0, %0, c1, c0, 1\n\t" : "=r"(x) : )
+
+/* Read L2 Control register */
+#define mrc_l2_ctlr(x) __asm__ __volatile__	\
+			("mrc     p15, 1, %0, c9, c0, 2\n\t" : "=r"(x) : )
+
+/* Read L2 Auxilliary Control register */
+#define mrc_l2_aux_ctlr(x) __asm__ __volatile__	\
+			("mrc     p15, 1, %0, c15, c0, 0\n\t" : "=r"(x) : )
+
+/* Write System Control Register */
+#define mcr_sctlr(x) __asm__ __volatile__	\
+			("mcr     p15, 0, %0, c1, c0, 0\n\t" : : "r"(x))
+
+/* Write Auxiliary Control Register */
+#define mcr_auxr(x) __asm__ __volatile__	\
+			("mcr     p15, 0, %0, c1, c0, 1\n\t" : : "r"(x))
+
+/* Invalidate all instruction caches to PoU */
+#define mcr_icache(x) __asm__ __volatile__	\
+			("mcr     p15, 0, %0, c7, c5, 0\n\t" : : "r"(x))
+
+/* Invalidate unified TLB */
+#define mcr_tlb(x) __asm__ __volatile__	\
+			("mcr     p15, 0, %0, c8, c7, 0\n\t" : : "r"(x))
+
+/* Write L2 Control register */
+#define mcr_l2_ctlr(x) __asm__ __volatile__	\
+			("mcr     p15, 1, %0, c9, c0, 2\n\t" : : "r"(x))
+
+/* Write L2 Auxilliary Control register */
+#define mcr_l2_aux_ctlr(x) __asm__ __volatile__	\
+			("mcr     p15, 1, %0, c15, c0, 0\n\t" : : "r"(x))
+#endif
+
 void set_usbhost_mode(unsigned int mode);
 void set_system_display_ctrl(void);
 int exynos_lcd_early_init(const void *blob);