[U-Boot] [PATCH v2 00/11] Add support for booting multiple cores

[U-Boot] [PATCH v2 00/11] Add support for booting multiple cores

[Akshay Saraswat]

This patch series introduces changes for booting secondary CPUs
on Exynos5420 and Exynos5800.

Changes since v1:
	- Added Reviewed-by & Tested-by in the acked patches.
	- Removed unnecessary CONFIGS and macros.
	- Changed names of few macros for better understanding in patch 2.
	- Added MPIDR bit assignment info comment in power_down_core in patch 2.
	- Changed to SPDX header in sec_boot.S in patch 5.
	- Fixed compilation error for snow build in patch 11.

Akshay Saraswat (10):
  Exynos542x: Config: Add various configs
  Exynos542x: CPU: Power down all secondary cores
  Exynos542x: Add workaround for ARM errata 798870
  Exynos542x: Add workaround for ARM errata 799270
  Exynos542x: Add workaround for exynos iROM errata
  Exynos542x: Change ambiguous function name set_l2cache
  Exynos542x: cache: Disable clean/evict push to external
  Exynos542x: add L2 control register configuration
  Exynos542x: Fix secondary core booting for thumb
  Exynos542x: Make A7s boot with thumb-mode U-Boot on warm reset

Doug Anderson (1):
  Exynos: Fix L2 cache timings on Exynos5420 and Exynos5800

 arch/arm/cpu/armv7/exynos/Makefile        |   2 +
 arch/arm/cpu/armv7/exynos/common_setup.h  |  55 ++++++++++
 arch/arm/cpu/armv7/exynos/exynos5_setup.h |   3 +
 arch/arm/cpu/armv7/exynos/lowlevel_init.c | 166 ++++++++++++++++++++++++++++++
 arch/arm/cpu/armv7/exynos/sec_boot.S      | 128 +++++++++++++++++++++++
 arch/arm/cpu/armv7/exynos/soc.c           |  35 -------
 arch/arm/include/asm/arch-exynos/cpu.h    |   5 +
 arch/arm/include/asm/arch-exynos/system.h |  88 ++++++++++++++++
 include/configs/exynos5420-common.h       |  16 +++
 9 files changed, 463 insertions(+), 35 deletions(-)
 create mode 100644 arch/arm/cpu/armv7/exynos/sec_boot.S

-- 
1.9.1

[U-Boot] [PATCH v2 01/11] Exynos542x: Config: Add various configs

[Akshay Saraswat]

This patch adds "iRAM, CPU state and low power" configs
which are the addresses acting as flag registers.

iROM code checks CONFIG_LOWPOWER_FLAG address. If it is equal
to CONFIG_LOWPOWER_EN then it jumps to the address (0x02020000+CPUID*4).
This is a part of iROM logic. Rest other flags are being used at
various places during kernel switching and reset.
They are nowhere documented because they are part programming.
These configs are serving as flags for us because they are
representing the addresses in iRAM which we are using for
storing and extracting CPU Status and GIC status.

Signed-off-by: Akshay Saraswat <akshay.s@samsung.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
---
Changes since v1:
	- Added Reviewed-by & Tested-by.
	- Removed unnecessary CONFIGS.

 include/configs/exynos5420-common.h | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/include/configs/exynos5420-common.h b/include/configs/exynos5420-common.h
index fe72bd0..b42dab7 100644
--- a/include/configs/exynos5420-common.h
+++ b/include/configs/exynos5420-common.h
@@ -38,4 +38,20 @@
 
 #define CONFIG_BOARD_REV_GPIO_COUNT	2
 
+#define CONFIG_PHY_IRAM_BASE		0x02020000
+
+/* Address for relocating helper code (Last 4 KB of IRAM) */
+#define CONFIG_EXYNOS_RELOCATE_CODE_BASE	(CONFIG_IRAM_TOP - 0x1000)
+
+/*
+ * Low Power settings
+ */
+#define CONFIG_LOWPOWER_FLAG		0x02020028
+#define CONFIG_LOWPOWER_ADDR		0x0202002C
+
+/*
+ * Number of CPUs available
+ */
+#define CONFIG_CORE_COUNT		0x8
+
 #endif	/* __CONFIG_EXYNOS5420_H */
-- 
1.9.1

[U-Boot] [PATCH v2 02/11] Exynos542x: CPU: Power down all secondary cores

[Akshay Saraswat]

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>
---
Changes since v1:
	- Removed unnecessary macros.
	- Changed names of few macros for better understanding.
	- Added MPIDR bit assignment info comment in power_down_core.

 arch/arm/cpu/armv7/exynos/exynos5_setup.h |  3 ++
 arch/arm/cpu/armv7/exynos/lowlevel_init.c | 69 ++++++++++++++++++++++++
 arch/arm/include/asm/arch-exynos/cpu.h    |  5 ++
 arch/arm/include/asm/arch-exynos/system.h | 87 +++++++++++++++++++++++++++++++
 4 files changed, 164 insertions(+)

diff --git a/arch/arm/cpu/armv7/exynos/exynos5_setup.h b/arch/arm/cpu/armv7/exynos/exynos5_setup.h
index 2eea48a..9073f50 100644
--- a/arch/arm/cpu/armv7/exynos/exynos5_setup.h
+++ b/arch/arm/cpu/armv7/exynos/exynos5_setup.h
@@ -700,6 +700,9 @@
 #define CLK_DIV_CPERI1_VAL	NOT_AVAILABLE
 
 #else
+
+#define CPU_CONFIG_STATUS_OFFSET	0x80
+#define CPU_RST_FLAG_VAL		0xFCBA0D10
 #define PAD_RETENTION_DRAM_COREBLK_VAL	0x10000000
 
 /* APLL_CON1 */
diff --git a/arch/arm/cpu/armv7/exynos/lowlevel_init.c b/arch/arm/cpu/armv7/exynos/lowlevel_init.c
index 83e1dcf..e36f2fa 100644
--- a/arch/arm/cpu/armv7/exynos/lowlevel_init.c
+++ b/arch/arm/cpu/armv7/exynos/lowlevel_init.c
@@ -31,7 +31,9 @@
 #include <asm/arch/tzpc.h>
 #include <asm/arch/periph.h>
 #include <asm/arch/pinmux.h>
+#include <asm/arch/system.h>
 #include "common_setup.h"
+#include "exynos5_setup.h"
 
 /* These are the things we can do during low-level init */
 enum {
@@ -42,6 +44,68 @@ enum {
 	DO_POWER	= 1 << 4,
 };
 
+#ifdef CONFIG_EXYNOS5420
+/*
+ * Pointer to this function is stored in iRam which is used
+ * for jump and power down of a specific core.
+ */
+static void power_down_core(void)
+{
+	uint32_t tmp, core_id, core_config;
+
+	/* Get the unique core id */
+	/*
+	 * Multiprocessor Affinity Register
+	 * [11:8]	Cluster ID
+	 * [1:0]	CPU ID
+	 */
+	mrc_mpafr(core_id);
+	tmp = core_id & 0x3;
+	core_id = (core_id >> 6) & ~3;
+	core_id |= tmp;
+	core_id &= 0x3f;
+
+	/* Set the status of the core to low */
+	core_config = (core_id * CPU_CONFIG_STATUS_OFFSET);
+	core_config += EXYNOS5420_CPU_CONFIG_BASE;
+	writel(0x0, core_config);
+
+	/* Core enter WFI */
+	wfi();
+}
+
+/*
+ * Configurations for secondary cores are inapt at this stage.
+ * Reconfigure secondary cores. Shutdown and change the status
+ * of all cores except the primary core.
+ */
+static void secondary_cores_configure(void)
+{
+	uint32_t core_id;
+
+	/* Store jump address for power down of secondary cores */
+	writel((uint32_t)&power_down_core, CONFIG_PHY_IRAM_BASE + 0x4);
+
+	/* Need all core power down check */
+	dsb();
+	sev();
+
+	/*
+	 * Power down all cores(secondary) while primary core must
+	 * wait for all cores to go down.
+	 */
+	for (core_id = 1; core_id != CONFIG_CORE_COUNT; core_id++) {
+		while ((readl(EXYNOS5420_CPU_STATUS_BASE
+			+ (core_id * CPU_CONFIG_STATUS_OFFSET))
+			& 0xff) != 0x0) {
+			isb();
+			sev();
+		}
+		isb();
+	}
+}
+#endif
+
 int do_lowlevel_init(void)
 {
 	uint32_t reset_status;
@@ -49,6 +113,11 @@ int do_lowlevel_init(void)
 
 	arch_cpu_init();
 
+#ifdef CONFIG_EXYNOS5420
+	/* Reconfigure secondary cores */
+	secondary_cores_configure();
+#endif
+
 	reset_status = get_reset_status();
 
 	switch (reset_status) {
diff --git a/arch/arm/include/asm/arch-exynos/cpu.h b/arch/arm/include/asm/arch-exynos/cpu.h
index 29674ad..e739520 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 4968d3d..86903c3 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);
-- 
1.9.1

[U-Boot] [PATCH v2 03/11] Exynos542x: Add workaround for ARM errata 798870

[Akshay Saraswat]

This patch adds workaround for ARM errata 798870 which says
"If back-to-back speculative cache line fills (fill A and fill B) are
issued from the L1 data cache of a CPU to the L2 cache, the second
request (fill B) is then cancelled, and the second request would have
detected a hazard against a recent write or eviction (write B) to the
same cache line as fill B then the L2 logic might deadlock."

Signed-off-by: Kimoon Kim <kimoon.kim@samsung.com>
Signed-off-by: Akshay Saraswat <akshay.s@samsung.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
---
Changes since v1:
	- Added Reviewed-by & Tested-by.
	- Added space before */ on line # 40.

 arch/arm/cpu/armv7/exynos/lowlevel_init.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/arch/arm/cpu/armv7/exynos/lowlevel_init.c b/arch/arm/cpu/armv7/exynos/lowlevel_init.c
index d599bd3..3ad5b78 100644
--- a/arch/arm/cpu/armv7/exynos/lowlevel_init.c
+++ b/arch/arm/cpu/armv7/exynos/lowlevel_init.c
@@ -46,6 +46,28 @@ enum {
 
 #ifdef CONFIG_EXYNOS5420
 /*
+ * Set L2ACTLR[7] to reissue any memory transaction in the L2 that has been
+ * stalled for 1024 cycles to verify that its hazard condition still exists.
+ */
+void set_l2cache(void)
+{
+	uint32_t val;
+
+	/* Read MIDR for Primary Part Number */
+	mrc_midr(val);
+	val = (val >> 4);
+	val &= 0xf;
+
+	/* L2ACTLR[7]: Enable hazard detect timeout for A15 */
+	if (val == 0xf) {
+		mrc_l2_aux_ctlr(val);
+		val |= (1 << 7);
+		mcr_l2_aux_ctlr(val);
+		mrc_l2_ctlr(val);
+	}
+}
+
+/*
  * Pointer to this function is stored in iRam which is used
  * for jump and power down of a specific core.
  */
-- 
1.9.1

[U-Boot] [PATCH v2 04/11] Exynos542x: Add workaround for ARM errata 799270

[Akshay Saraswat]

This patch adds workaround for the ARM errata 799270 which says
"If the L2 cache logic clock is stopped because of L2 inactivity,
setting or clearing the ACTLR.SMP bit might not be effective. The bit is
modified in the ACTLR, meaning a read of the register returns the
updated value. However the logic that uses that bit retains the previous
value."

Signed-off-by: Kimoon Kim <kimoon.kim@samsung.com>
Signed-off-by: Akshay Saraswat <akshay.s@samsung.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
---
Changes since v1:
	- Added Reviewed-by & Tested-by.

 arch/arm/cpu/armv7/exynos/lowlevel_init.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/arch/arm/cpu/armv7/exynos/lowlevel_init.c b/arch/arm/cpu/armv7/exynos/lowlevel_init.c
index 3ad5b78..3ebbf84 100644
--- a/arch/arm/cpu/armv7/exynos/lowlevel_init.c
+++ b/arch/arm/cpu/armv7/exynos/lowlevel_init.c
@@ -46,6 +46,28 @@ enum {
 
 #ifdef CONFIG_EXYNOS5420
 /*
+ * Ensure that the L2 logic has been used within the previous 256 cycles
+ * before modifying the ACTLR.SMP bit. This is required during boot before
+ * MMU has been enabled, or during a specified reset or power down sequence.
+ */
+void enable_smp(void)
+{
+	uint32_t temp, val;
+
+	/* Enable SMP mode */
+	mrc_auxr(temp);
+	temp |= (1 << 6);
+
+	/* Dummy read to assure L2 access */
+	val = readl(EXYNOS5420_INFORM_BASE);
+	val &= 0;
+	temp |= val;
+	mcr_auxr(temp);
+	dsb();
+	isb();
+}
+
+/*
  * Set L2ACTLR[7] to reissue any memory transaction in the L2 that has been
  * stalled for 1024 cycles to verify that its hazard condition still exists.
  */
-- 
1.9.1

[U-Boot] [PATCH v2 05/11] Exynos542x: Add workaround for exynos iROM errata

[Akshay Saraswat]

iROM logic provides undesired jump address for CPU2.
This patch adds a programmable susbstitute for a part of
iROM logic which wakes up cores and provides jump addresses.
This patch creates a logic to make all secondary cores jump
to a particular address which evades the possibility of CPU2
jumping to wrong address and create undesired results.

Logic of the workaround:

Step-1: iROM code checks value at address 0x2020028.
Step-2: If value is 0xc9cfcfcf, it jumps to the address (0x202000+CPUid*4),
	else, it continues executing normally.
Step-3: Primary core puts secondary cores in WFE and store 0xc9cfcfcf in
	0x2020028 and jump address (pointer to function low_power_start)
	in (0x202000+CPUid*4).
Step-4: When secondary cores recieve event signal they jump to this address
	and continue execution.

Signed-off-by: Kimoon Kim <kimoon.kim@samsung.com>
Signed-off-by: Akshay Saraswat <akshay.s@samsung.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
---
Changes since v1:
	- Added Reviewed-by & Tested-by.
	- Changed to SPDX header in sec_boot.S.

 arch/arm/cpu/armv7/exynos/Makefile        |   2 +
 arch/arm/cpu/armv7/exynos/lowlevel_init.c |  90 ++++++++++++++++-----
 arch/arm/cpu/armv7/exynos/sec_boot.S      | 128 ++++++++++++++++++++++++++++++
 3 files changed, 202 insertions(+), 18 deletions(-)
 create mode 100644 arch/arm/cpu/armv7/exynos/sec_boot.S

diff --git a/arch/arm/cpu/armv7/exynos/Makefile b/arch/arm/cpu/armv7/exynos/Makefile
index e207bd6..8542f89 100644
--- a/arch/arm/cpu/armv7/exynos/Makefile
+++ b/arch/arm/cpu/armv7/exynos/Makefile
@@ -7,6 +7,8 @@
 
 obj-y	+= clock.o power.o soc.o system.o pinmux.o tzpc.o
 
+obj-$(CONFIG_EXYNOS5420)	+= sec_boot.o
+
 ifdef CONFIG_SPL_BUILD
 obj-$(CONFIG_EXYNOS5)	+= clock_init_exynos5.o
 obj-$(CONFIG_EXYNOS5)	+= dmc_common.o dmc_init_ddr3.o
diff --git a/arch/arm/cpu/armv7/exynos/lowlevel_init.c b/arch/arm/cpu/armv7/exynos/lowlevel_init.c
index 3ebbf84..527d20b 100644
--- a/arch/arm/cpu/armv7/exynos/lowlevel_init.c
+++ b/arch/arm/cpu/armv7/exynos/lowlevel_init.c
@@ -50,7 +50,7 @@ enum {
  * before modifying the ACTLR.SMP bit. This is required during boot before
  * MMU has been enabled, or during a specified reset or power down sequence.
  */
-void enable_smp(void)
+static void enable_smp(void)
 {
 	uint32_t temp, val;
 
@@ -71,7 +71,7 @@ void enable_smp(void)
  * Set L2ACTLR[7] to reissue any memory transaction in the L2 that has been
  * stalled for 1024 cycles to verify that its hazard condition still exists.
  */
-void set_l2cache(void)
+static void set_l2cache(void)
 {
 	uint32_t val;
 
@@ -90,6 +90,62 @@ void set_l2cache(void)
 }
 
 /*
+ * Power up secondary CPUs.
+ */
+static void secondary_cpu_start(void)
+{
+	enable_smp();
+	svc32_mode_en();
+	set_pc(CONFIG_EXYNOS_RELOCATE_CODE_BASE);
+}
+
+/*
+ * This is the entry point of hotplug-in and
+ * cluster switching.
+ */
+static void low_power_start(void)
+{
+	uint32_t val, reg_val;
+
+	reg_val = readl(EXYNOS5420_SPARE_BASE);
+	if (reg_val != CPU_RST_FLAG_VAL) {
+		writel(0x0, CONFIG_LOWPOWER_FLAG);
+		set_pc(0x0);
+	}
+
+	reg_val = readl(CONFIG_PHY_IRAM_BASE + 0x4);
+	if (reg_val != (uint32_t)&low_power_start) {
+		/* Store jump address as low_power_start if not present */
+		writel((uint32_t)&low_power_start, CONFIG_PHY_IRAM_BASE + 0x4);
+		dsb();
+		sev();
+	}
+
+	/* Set the CPU to SVC32 mode */
+	svc32_mode_en();
+	set_l2cache();
+
+	/* Invalidate L1 & TLB */
+	val = 0x0;
+	mcr_tlb(val);
+	mcr_icache(val);
+
+	/* Disable MMU stuff and caches */
+	mrc_sctlr(val);
+
+	val &= ~((0x2 << 12) | 0x7);
+	val |= ((0x1 << 12) | (0x8 << 8) | 0x2);
+	mcr_sctlr(val);
+
+	/* CPU state is hotplug or reset */
+	secondary_cpu_start();
+
+	/* Core should not enter into WFI here */
+	wfi();
+
+}
+
+/*
  * Pointer to this function is stored in iRam which is used
  * for jump and power down of a specific core.
  */
@@ -119,29 +175,25 @@ static void power_down_core(void)
  */
 static void secondary_cores_configure(void)
 {
-	uint32_t core_id;
+	/* Setup L2 cache */
+	set_l2cache();
+
+	/* Clear secondary boot iRAM base */
+	writel(0x0, (CONFIG_EXYNOS_RELOCATE_CODE_BASE + 0x1C));
 
-	/* Store jump address for power down of secondary cores */
+	/* set lowpower flag and address */
+	writel(CPU_RST_FLAG_VAL, CONFIG_LOWPOWER_FLAG);
+	writel((uint32_t)&low_power_start, CONFIG_LOWPOWER_ADDR);
+	writel(CPU_RST_FLAG_VAL, EXYNOS5420_SPARE_BASE);
+	/* Store jump address for power down */
 	writel((uint32_t)&power_down_core, CONFIG_PHY_IRAM_BASE + 0x4);
 
 	/* Need all core power down check */
 	dsb();
 	sev();
-
-	/*
-	 * Power down all cores(secondary) while primary core must
-	 * wait for all cores to go down.
-	 */
-	for (core_id = 1; core_id != CONFIG_CORE_COUNT; core_id++) {
-		while ((readl(EXYNOS5420_CPU_STATUS_BASE
-			+ (core_id * CPU_CONFIG_STATUS_OFFSET))
-			& 0xff) != 0x0) {
-			isb();
-			sev();
-		}
-		isb();
-	}
 }
+
+extern void relocate_wait_code(void);
 #endif
 
 int do_lowlevel_init(void)
@@ -152,6 +204,8 @@ int do_lowlevel_init(void)
 	arch_cpu_init();
 
 #ifdef CONFIG_EXYNOS5420
+	relocate_wait_code();
+
 	/* Reconfigure secondary cores */
 	secondary_cores_configure();
 #endif
diff --git a/arch/arm/cpu/armv7/exynos/sec_boot.S b/arch/arm/cpu/armv7/exynos/sec_boot.S
new file mode 100644
index 0000000..dfc3455
--- /dev/null
+++ b/arch/arm/cpu/armv7/exynos/sec_boot.S
@@ -0,0 +1,128 @@
+/*
+ * Copyright (C) 2013 Samsung Electronics
+ * Akshay Saraswat <akshay.s@samsung.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <config.h>
+#include <asm/arch/cpu.h>
+
+	.globl relocate_wait_code
+relocate_wait_code:
+	adr     r0, code_base		@ r0: source address (start)
+	adr     r1, code_end		@ r1: source address (end)
+	ldr     r2, =0x02073000		@ r2: target address
+1:
+	ldmia   r0!, {r3-r6}
+	stmia   r2!, {r3-r6}
+	cmp     r0, r1
+	blt     1b
+	b	code_end
+	.ltorg
+/*
+ * Secondary core waits here until Primary wake it up.
+ * Below code is copied to CONFIG_EXYNOS_RELOCATE_CODE_BASE.
+ * This is a workaround code which is supposed to act as a
+ * substitute/supplement to the iROM code.
+ *
+ * This workaround code is relocated to the address 0x02073000
+ * because that comes out to be the last 4KB of the iRAM
+ * (Base Address - 0x02020000, Limit Address - 0x020740000).
+ *
+ * U-boot and kernel are aware of this code and flags by the simple
+ * fact that we are implementing a workaround in the last 4KB
+ * of the iRAM and we have already defined these flag and address
+ * values in both kernel and U-boot for our use.
+ */
+code_base:
+	b	 1f
+/*
+ * These addresses are being used as flags in u-boot and kernel.
+ *
+ * Jump address for resume and flag to check for resume/reset:
+ * Resume address - 0x2073008
+ * Resume flag - 0x207300C
+ *
+ * Jump address for cluster switching:
+ * Switch address - 0x2073018
+ *
+ * Jump address for core hotplug:
+ * Hotplug address - 0x207301C
+ *
+ * Jump address for C2 state (Reserved for future not being used right now):
+ * C2 address - 0x2073024
+ *
+ * Managed per core status for the active cluster:
+ * CPU0 state - 0x2073028
+ * CPU1 state - 0x207302C
+ * CPU2 state - 0x2073030
+ * CPU3 state - 0x2073034
+ *
+ * Managed per core GIC status for the active cluster:
+ * CPU0 gic state - 0x2073038
+ * CPU1 gic state - 0x207303C
+ * CPU2 gic state - 0x2073040
+ * CPU3 gic state - 0x2073044
+ *
+ * Logic of the code:
+ * Step-1: Read current CPU status.
+ * Step-2: If it's a resume then continue, else jump to step 4.
+ * Step-3: Clear inform1 PMU register and jump to inform0 value.
+ * Step-4: If it's a switch, C2 or reset, get the hotplug address.
+ * Step-5: If address is not available, enter WFE.
+ * Step-6: If address is available, jump to that address.
+ */
+	nop			     @ for backward compatibility
+	.word   0x0		     @ REG0: RESUME_ADDR
+	.word   0x0		     @ REG1: RESUME_FLAG
+	.word   0x0		     @ REG2
+	.word   0x0		     @ REG3
+_switch_addr:
+	.word   0x0		     @ REG4: SWITCH_ADDR
+_hotplug_addr:
+	.word   0x0		     @ REG5: CPU1_BOOT_REG
+	.word   0x0		     @ REG6
+_c2_addr:
+	.word   0x0		     @ REG7: REG_C2_ADDR
+_cpu_state:
+	.word   0x1		     @ CPU0_STATE : RESET
+	.word   0x2		     @ CPU1_STATE : SECONDARY RESET
+	.word   0x2		     @ CPU2_STATE : SECONDARY RESET
+	.word   0x2		     @ CPU3_STATE : SECONDARY RESET
+_gic_state:
+	.word   0x0		     @ CPU0 - GICD_IGROUPR0
+	.word   0x0		     @ CPU1 - GICD_IGROUPR0
+	.word   0x0		     @ CPU2 - GICD_IGROUPR0
+	.word   0x0		     @ CPU3 - GICD_IGROUPR0
+1:
+	adr     r0, _cpu_state
+	mrc     p15, 0, r7, c0, c0, 5   @ read MPIDR
+	and     r7, r7, #0xf	    @ r7 = cpu id
+/* Read the current cpu state */
+	ldr     r10, [r0, r7, lsl #2]
+svc_entry:
+	tst     r10, #(1 << 4)
+	adrne   r0, _switch_addr
+	bne     wait_for_addr
+/* Clear INFORM1 */
+	ldr     r0, =(0x10040000 + 0x804)
+	ldr     r1, [r0]
+	cmp     r1, #0x0
+	movne   r1, #0x0
+	strne   r1, [r0]
+/* Get INFORM0 */
+	ldrne   r1, =(0x10040000 + 0x800)
+	ldrne   pc, [r1]
+	tst     r10, #(1 << 0)
+	ldrne   pc, =0x23e00000
+	adr     r0, _hotplug_addr
+wait_for_addr:
+	ldr     r1, [r0]
+	cmp     r1, #0x0
+	bxne    r1
+	wfe
+	b	 wait_for_addr
+	.ltorg
+code_end:
+	mov	pc, lr
-- 
1.9.1

[U-Boot] [PATCH v2 06/11] Exynos542x: Change ambiguous function name set_l2cache

[Akshay Saraswat]

1. Renaming set_l2cache to configure_l2actlr in order to avoid
   misleading comprehensions. Apparently this name suggests
   that L2 cache is being set or initialized which is incorrect
   as per the code in this function.
2. Cleaning missed mrc for L2 control register.

Signed-off-by: Akshay Saraswat <akshay.s@samsung.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
---
Changes since v1:
	- Added Reviewed-by & Tested-by.

 arch/arm/cpu/armv7/exynos/lowlevel_init.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/arch/arm/cpu/armv7/exynos/lowlevel_init.c b/arch/arm/cpu/armv7/exynos/lowlevel_init.c
index 527d20b..1c70e54 100644
--- a/arch/arm/cpu/armv7/exynos/lowlevel_init.c
+++ b/arch/arm/cpu/armv7/exynos/lowlevel_init.c
@@ -71,7 +71,7 @@ static void enable_smp(void)
  * Set L2ACTLR[7] to reissue any memory transaction in the L2 that has been
  * stalled for 1024 cycles to verify that its hazard condition still exists.
  */
-static void set_l2cache(void)
+static void configure_l2actlr(void)
 {
 	uint32_t val;
 
@@ -85,7 +85,6 @@ static void set_l2cache(void)
 		mrc_l2_aux_ctlr(val);
 		val |= (1 << 7);
 		mcr_l2_aux_ctlr(val);
-		mrc_l2_ctlr(val);
 	}
 }
 
@@ -123,7 +122,7 @@ static void low_power_start(void)
 
 	/* Set the CPU to SVC32 mode */
 	svc32_mode_en();
-	set_l2cache();
+	configure_l2actlr();
 
 	/* Invalidate L1 & TLB */
 	val = 0x0;
@@ -176,7 +175,7 @@ static void power_down_core(void)
 static void secondary_cores_configure(void)
 {
 	/* Setup L2 cache */
-	set_l2cache();
+	configure_l2actlr();
 
 	/* Clear secondary boot iRAM base */
 	writel(0x0, (CONFIG_EXYNOS_RELOCATE_CODE_BASE + 0x1C));
-- 
1.9.1

[U-Boot] [PATCH v2 07/11] Exynos542x: cache: Disable clean/evict push to external

[Akshay Saraswat]

L2 Auxiliary Control Register provides configuration
and control options for the L2 memory system. Bit 3
of L2ACTLR stands for clean/evict push to external.
Setting bit 3 disables clean/evict which is what
this patch intends to do.

Signed-off-by: Akshay Saraswat <akshay.s@samsung.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
---
Changes since v1:
	- Added Reviewed-by & Tested-by.

 arch/arm/cpu/armv7/exynos/soc.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/arch/arm/cpu/armv7/exynos/soc.c b/arch/arm/cpu/armv7/exynos/soc.c
index 8c7d7d8..7268b9b 100644
--- a/arch/arm/cpu/armv7/exynos/soc.c
+++ b/arch/arm/cpu/armv7/exynos/soc.c
@@ -45,6 +45,15 @@ static void exynos5_set_l2cache_params(void)
 		CACHE_DATA_RAM_LATENCY;
 
 	asm volatile("mcr p15, 1, %0, c9, c0, 2\n" : : "r"(val));
+
+#ifdef CONFIG_EXYNOS5420
+	/* Read CP15 L2ACTLR value */
+	asm volatile("mrc	p15, 1, %0, c15, c0, 0" : "=r" (val));
+	/* Disable clean/evict push to external */
+	val |= (0x1 << 3);
+	/* Write new vlaue to L2ACTLR */
+	asm volatile("mcr	p15, 1, %0, c15, c0, 0" : : "r" (val));
+#endif
 }
 
 /*
-- 
1.9.1

[U-Boot] [PATCH v2 08/11] Exynos542x: add L2 control register configuration

[Akshay Saraswat]

This patch does 3 things:
1. Enables ECC by setting 21st bit of L2CTLR.
2. Restore data and tag RAM latencies to 3 cycles because iROM sets
   0x3000400 L2CTLR value during switching.
3. Disable clean/evict push to external by setting 3rd bit of L2ACTLR.
   We need to restore this here due to switching.

Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
Signed-off-by: Akshay Saraswat <akshay.s@samsung.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
---
Changes since v1:
	- Added Reviewed-by & Tested-by.

 arch/arm/cpu/armv7/exynos/lowlevel_init.c | 53 +++++++++++++++++++++++--------
 arch/arm/cpu/armv7/exynos/soc.c           |  7 ++++
 2 files changed, 46 insertions(+), 14 deletions(-)

diff --git a/arch/arm/cpu/armv7/exynos/lowlevel_init.c b/arch/arm/cpu/armv7/exynos/lowlevel_init.c
index 1c70e54..9892e6b 100644
--- a/arch/arm/cpu/armv7/exynos/lowlevel_init.c
+++ b/arch/arm/cpu/armv7/exynos/lowlevel_init.c
@@ -68,24 +68,40 @@ static void enable_smp(void)
 }
 
 /*
+ * Enable ECC by setting L2CTLR[21].
+ * Set L2CTLR[7] to make tag ram latency 3 cycles and
+ * set L2CTLR[1] to make data ram latency 3 cycles.
+ * We need to make RAM latency of 3 cycles here because cores
+ * power ON and OFF while switching. And everytime a core powers
+ * ON, iROM provides it a default L2CTLR value 0x400 which stands
+ * for TAG RAM setup of 1 cycle. Hence, we face a need of
+ * restoring data and tag latency values.
+ */
+static void configure_l2_ctlr(void)
+{
+	uint32_t val;
+
+	mrc_l2_ctlr(val);
+	val |= (1 << 21);
+	val |= (1 << 7);
+	val |= (1 << 1);
+	mcr_l2_ctlr(val);
+}
+
+/*
  * Set L2ACTLR[7] to reissue any memory transaction in the L2 that has been
  * stalled for 1024 cycles to verify that its hazard condition still exists.
+ * Disable clean/evict push to external by setting L2ACTLR[3].
  */
-static void configure_l2actlr(void)
+static void configure_l2_actlr(void)
 {
 	uint32_t val;
 
-	/* Read MIDR for Primary Part Number */
-	mrc_midr(val);
-	val = (val >> 4);
-	val &= 0xf;
-
-	/* L2ACTLR[7]: Enable hazard detect timeout for A15 */
-	if (val == 0xf) {
-		mrc_l2_aux_ctlr(val);
-		val |= (1 << 7);
-		mcr_l2_aux_ctlr(val);
-	}
+	mrc_l2_aux_ctlr(val);
+	val |= (1 << 27);
+	val |= (1 << 7);
+	val |= (1 << 3);
+	mcr_l2_aux_ctlr(val);
 }
 
 /*
@@ -122,7 +138,16 @@ static void low_power_start(void)
 
 	/* Set the CPU to SVC32 mode */
 	svc32_mode_en();
-	configure_l2actlr();
+
+	/* Read MIDR for Primary Part Number */
+	mrc_midr(val);
+	val = (val >> 4);
+	val &= 0xf;
+
+	if (val == 0xf) {
+		configure_l2_ctlr();
+		configure_l2_actlr();
+	}
 
 	/* Invalidate L1 & TLB */
 	val = 0x0;
@@ -175,7 +200,7 @@ static void power_down_core(void)
 static void secondary_cores_configure(void)
 {
 	/* Setup L2 cache */
-	configure_l2actlr();
+	configure_l2_ctlr();
 
 	/* Clear secondary boot iRAM base */
 	writel(0x0, (CONFIG_EXYNOS_RELOCATE_CODE_BASE + 0x1C));
diff --git a/arch/arm/cpu/armv7/exynos/soc.c b/arch/arm/cpu/armv7/exynos/soc.c
index 7268b9b..ea201e7 100644
--- a/arch/arm/cpu/armv7/exynos/soc.c
+++ b/arch/arm/cpu/armv7/exynos/soc.c
@@ -10,8 +10,10 @@
 #include <asm/system.h>
 
 enum l2_cache_params {
+#ifndef CONFIG_EXYNOS5420
 	CACHE_TAG_RAM_SETUP = (1 << 9),
 	CACHE_DATA_RAM_SETUP = (1 << 5),
+#endif
 	CACHE_TAG_RAM_LATENCY = (2 << 6),
 	CACHE_DATA_RAM_LATENCY = (2 << 0)
 };
@@ -39,10 +41,15 @@ static void exynos5_set_l2cache_params(void)
 
 	asm volatile("mrc p15, 1, %0, c9, c0, 2\n" : "=r"(val));
 
+#ifndef CONFIG_EXYNOS5420
 	val |= CACHE_TAG_RAM_SETUP |
 		CACHE_DATA_RAM_SETUP |
 		CACHE_TAG_RAM_LATENCY |
 		CACHE_DATA_RAM_LATENCY;
+#else
+	val |= CACHE_TAG_RAM_LATENCY |
+		CACHE_DATA_RAM_LATENCY;
+#endif
 
 	asm volatile("mcr p15, 1, %0, c9, c0, 2\n" : : "r"(val));
 
-- 
1.9.1

[U-Boot] [PATCH v2 09/11] Exynos542x: Fix secondary core booting for thumb

[Akshay Saraswat]

When compiled SPL for Thumb secondary cores failed to boot
at the kernel boot up. Only one core came up out of 4.
This was happening because the code relocated to the
address 0x02073000 by the primary core was an ARM asm
code which was executed by the secondary cores as if it
was a thumb code.
This patch fixes the issue of secondary cores considering
relocated code as Thumb instructions and not ARM instructions
by jumping to the relocated with the help of "bx" ARM instruction.
"bx" instruction changes the 5th bit of CPSR which allows
execution unit to consider the following instructions as ARM
instructions.

Signed-off-by: Akshay Saraswat <akshay.s@samsung.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
---
Changes since v1:
	- Added Reviewed-by & Tested-by.

 arch/arm/cpu/armv7/exynos/lowlevel_init.c | 2 +-
 arch/arm/include/asm/arch-exynos/system.h | 3 +++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/arm/cpu/armv7/exynos/lowlevel_init.c b/arch/arm/cpu/armv7/exynos/lowlevel_init.c
index 9892e6b..3fbaaf3 100644
--- a/arch/arm/cpu/armv7/exynos/lowlevel_init.c
+++ b/arch/arm/cpu/armv7/exynos/lowlevel_init.c
@@ -111,7 +111,7 @@ static void secondary_cpu_start(void)
 {
 	enable_smp();
 	svc32_mode_en();
-	set_pc(CONFIG_EXYNOS_RELOCATE_CODE_BASE);
+	branch_bx(CONFIG_EXYNOS_RELOCATE_CODE_BASE);
 }
 
 /*
diff --git a/arch/arm/include/asm/arch-exynos/system.h b/arch/arm/include/asm/arch-exynos/system.h
index 86903c3..a9fd5e6 100644
--- a/arch/arm/include/asm/arch-exynos/system.h
+++ b/arch/arm/include/asm/arch-exynos/system.h
@@ -75,6 +75,9 @@ struct exynos5_sysreg {
 /* Set program counter with the given value */
 #define set_pc(x) __asm__ __volatile__ ("mov     pc, %0\n\t" : : "r"(x))
 
+/* Branch to the given location */
+#define branch_bx(x) __asm__ __volatile__ ("bx	%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) : )
-- 
1.9.1

[U-Boot] [PATCH v2 10/11] Exynos542x: Make A7s boot with thumb-mode U-Boot on warm reset

[Akshay Saraswat]

On warm reset, all cores jump to the low_power_start function because iRAM
data is retained and because while executing iROM code all cores find
the jump flag 0x02020028 set. In low_power_start, cores check the reset
status and if true they clear the jump flag and jump back to 0x0.

The A7 cores do jump to 0x0 but consider following instructions as a Thumb
instructions which in turn makes them loop inside the iROM code instead of
jumping to power_down_core.

This issue is fixed by replacing the "mov pc" instruction with a "bx"
instruction which switches state along with the jump to make the execution
unit consider the branch target as an ARM instruction.

Signed-off-by: Akshay Saraswat <akshay.s@samsung.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
---
Changes since v1:
	- Added Reviewed-by & Tested-by.

 arch/arm/cpu/armv7/exynos/lowlevel_init.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/cpu/armv7/exynos/lowlevel_init.c b/arch/arm/cpu/armv7/exynos/lowlevel_init.c
index 3fbaaf3..e9e3cb7 100644
--- a/arch/arm/cpu/armv7/exynos/lowlevel_init.c
+++ b/arch/arm/cpu/armv7/exynos/lowlevel_init.c
@@ -125,7 +125,7 @@ static void low_power_start(void)
 	reg_val = readl(EXYNOS5420_SPARE_BASE);
 	if (reg_val != CPU_RST_FLAG_VAL) {
 		writel(0x0, CONFIG_LOWPOWER_FLAG);
-		set_pc(0x0);
+		branch_bx(0x0);
 	}
 
 	reg_val = readl(CONFIG_PHY_IRAM_BASE + 0x4);
-- 
1.9.1

[U-Boot] [PATCH v2 11/11] Exynos: Fix L2 cache timings on Exynos5420 and Exynos5800

[Akshay Saraswat]

From: Doug Anderson <dianders@chromium.org>

It was found that the L2 cache timings that we had before could cause
freezes and hangs.  We should make things more robust with better
timings.  Currently the production ChromeOS kernel applies these
timings, but it's nice to fixup firmware too (and upstream probably
won't take our kernel hacks).

This also provides a big cleanup of the L2 cache init code avoiding
some duplication.  The way things used to work:
* low_power_start() was installed by the SPL (both at boot and resume
  time) and left resident in iRAM for the kernel to use when bringing
  up additional CPUs.  It used configure_l2_ctlr() and
  configure_l2_actlr() when it detected it was on an A15.  This was
  needed (despite the L2 cache registers being shared among all A15s)
  because we might have been the first man in after the whole A15
  cluster was shutdown.
* secondary_cores_configure() was called on at boot time and at resume
  time.  Strangely this called configure_l2_ctlr() but not
  configure_l2_actlr() which was almost certainly wrong.  Given that
  we'll call both (see next bullet) later in the boot process it
  didn't matter for normal boot, but I guess this is how L2 cache
  settings got set on 5420/5800 (but not 5250?) at resume time.
* exynos5_set_l2cache_params() was called as part of cache enablement.
  This should happen at boot time (normally in the SPL except for USB
  boot where it happens in main U-Boot).

Note that the old code wasn't setting ECC/parity in the cache
enablement code but we happened to get it anyway because we'd call
secondary_cores_configure() at boot time.  For resume time we'd get it
anyway when the 2nd A15 core came up.

Let's make this a whole lot simpler.  Now we always set these
parameters in the same place for all boots and use the same code for
setting up secondary CPUs.

Intended net effects of this change (other than cleanup):
* Timings go from before:
    data: 0 cycle setup, 3 cycles (0x2) latency
    tag:  0 cycle setup, 3 cycles (0x2) latency
  after:
    data: 1 cycle setup, 4 cycles (0x3) latency
    tag:  1 cycle setup, 4 cycles (0x3) latency
* L2ACTLR is properly initted on 5420/5800 in all cases.

One note is that we're still relying on luck to keep low_power_start()
working.  The compiler is being nice and not storing anything on the
stack.

Another note is that on its own this patch won't help to fix cache
settings in an RW U-Boot update where we still have the RO SPL.  The
plan for that is:
* Have RW U-Boot re-init the cache right before calling the kernel
  (after it has turned the L2 cache off).  This is why the functions
  are in a header file instead of lowlevel_init.c.

* Have the kernel save the L2 cache settings of the boot CPU and apply
  them to all other CPUs.  We get a little lucky here because the old
  code was using "|=" to modify the registers and all of the bits that
  it's setting are also present in the new settings (!).  That means
  that when the 2nd CPU in the A15 cluster comes up it doesn't
  actually mess up the settings of the 1st CPU in the A15 cluster.  An
  alternative option is to have the kernel write its own
  low_power_start() code.

Signed-off-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Akshay Saraswat <akshay.s@samsung.com>
---
Changes since v1:
	- Fixed compilation error for snow build.

 arch/arm/cpu/armv7/exynos/common_setup.h  | 55 +++++++++++++++++++++++++++++++
 arch/arm/cpu/armv7/exynos/lowlevel_init.c | 55 +++++++++----------------------
 arch/arm/cpu/armv7/exynos/soc.c           | 51 ----------------------------
 arch/arm/include/asm/arch-exynos/system.h |  2 --
 4 files changed, 70 insertions(+), 93 deletions(-)

diff --git a/arch/arm/cpu/armv7/exynos/common_setup.h b/arch/arm/cpu/armv7/exynos/common_setup.h
index e6318c0..4c00186 100644
--- a/arch/arm/cpu/armv7/exynos/common_setup.h
+++ b/arch/arm/cpu/armv7/exynos/common_setup.h
@@ -23,6 +23,8 @@
  * MA 02111-1307 USA
  */
 
+#include <asm/arch/system.h>
+
 #define DMC_OFFSET	0x10000
 
 /*
@@ -43,3 +45,56 @@ void system_clock_init(void);
 int do_lowlevel_init(void);
 
 void sdelay(unsigned long);
+
+enum l2_cache_params {
+	CACHE_ECC_AND_PARITY = (1 << 21),
+	CACHE_TAG_RAM_SETUP = (1 << 9),
+	CACHE_DATA_RAM_SETUP = (1 << 5),
+#ifndef CONFIG_EXYNOS5420
+	CACHE_TAG_RAM_LATENCY = (2 << 6),  /* 5250 */
+	CACHE_DATA_RAM_LATENCY = (2 << 0),
+#else
+	CACHE_TAG_RAM_LATENCY = (3 << 6),  /* 5420 and 5800 */
+	CACHE_DATA_RAM_LATENCY = (3 << 0),
+#endif
+};
+
+#ifndef CONFIG_SYS_L2CACHE_OFF
+/*
+ * Configure L2CTLR to get timings that keep us from hanging/crashing.
+ *
+ * Must be inline here since low_power_start() is called without a
+ * stack (!).
+ */
+static inline void configure_l2_ctlr(void)
+{
+	uint32_t val;
+
+	mrc_l2_ctlr(val);
+	val |= CACHE_TAG_RAM_SETUP |
+		CACHE_DATA_RAM_SETUP |
+		CACHE_TAG_RAM_LATENCY |
+		CACHE_DATA_RAM_LATENCY |
+		CACHE_ECC_AND_PARITY;
+	mcr_l2_ctlr(val);
+}
+
+/*
+ * Configure L2ACTLR.
+ *
+ * Must be inline here since low_power_start() is called without a
+ * stack (!).
+ */
+static inline void configure_l2_actlr(void)
+{
+#ifdef CONFIG_EXYNOS5420
+	uint32_t val;
+
+	mrc_l2_aux_ctlr(val);
+	val |= (1 << 27) |	/* Prevents stopping the L2 logic clock */
+		(1 << 7) |	/* Enable hazard detect timeout for A15 */
+		(1 << 3);	/* Disable clean/evict push to external */
+	mcr_l2_aux_ctlr(val);
+#endif
+}
+#endif
diff --git a/arch/arm/cpu/armv7/exynos/lowlevel_init.c b/arch/arm/cpu/armv7/exynos/lowlevel_init.c
index e9e3cb7..25215c8 100644
--- a/arch/arm/cpu/armv7/exynos/lowlevel_init.c
+++ b/arch/arm/cpu/armv7/exynos/lowlevel_init.c
@@ -68,43 +68,6 @@ static void enable_smp(void)
 }
 
 /*
- * Enable ECC by setting L2CTLR[21].
- * Set L2CTLR[7] to make tag ram latency 3 cycles and
- * set L2CTLR[1] to make data ram latency 3 cycles.
- * We need to make RAM latency of 3 cycles here because cores
- * power ON and OFF while switching. And everytime a core powers
- * ON, iROM provides it a default L2CTLR value 0x400 which stands
- * for TAG RAM setup of 1 cycle. Hence, we face a need of
- * restoring data and tag latency values.
- */
-static void configure_l2_ctlr(void)
-{
-	uint32_t val;
-
-	mrc_l2_ctlr(val);
-	val |= (1 << 21);
-	val |= (1 << 7);
-	val |= (1 << 1);
-	mcr_l2_ctlr(val);
-}
-
-/*
- * Set L2ACTLR[7] to reissue any memory transaction in the L2 that has been
- * stalled for 1024 cycles to verify that its hazard condition still exists.
- * Disable clean/evict push to external by setting L2ACTLR[3].
- */
-static void configure_l2_actlr(void)
-{
-	uint32_t val;
-
-	mrc_l2_aux_ctlr(val);
-	val |= (1 << 27);
-	val |= (1 << 7);
-	val |= (1 << 3);
-	mcr_l2_aux_ctlr(val);
-}
-
-/*
  * Power up secondary CPUs.
  */
 static void secondary_cpu_start(void)
@@ -199,9 +162,6 @@ static void power_down_core(void)
  */
 static void secondary_cores_configure(void)
 {
-	/* Setup L2 cache */
-	configure_l2_ctlr();
-
 	/* Clear secondary boot iRAM base */
 	writel(0x0, (CONFIG_EXYNOS_RELOCATE_CODE_BASE + 0x1C));
 
@@ -227,6 +187,21 @@ int do_lowlevel_init(void)
 
 	arch_cpu_init();
 
+#ifndef CONFIG_SYS_L2CACHE_OFF
+	/*
+	 * Init L2 cache parameters here for use by boot and resume
+	 *
+	 * These are here instead of in v7_outer_cache_enable() so that the
+	 * L2 cache settings get properly set even@resume time or if we're
+	 * running U-Boot with the cache off.  The kernel still needs us to
+	 * set these for it.
+	 */
+	configure_l2_ctlr();
+	configure_l2_actlr();
+	dsb();
+	isb();
+#endif
+
 #ifdef CONFIG_EXYNOS5420
 	relocate_wait_code();
 
diff --git a/arch/arm/cpu/armv7/exynos/soc.c b/arch/arm/cpu/armv7/exynos/soc.c
index ea201e7..0f116b1 100644
--- a/arch/arm/cpu/armv7/exynos/soc.c
+++ b/arch/arm/cpu/armv7/exynos/soc.c
@@ -9,15 +9,6 @@
 #include <asm/io.h>
 #include <asm/system.h>
 
-enum l2_cache_params {
-#ifndef CONFIG_EXYNOS5420
-	CACHE_TAG_RAM_SETUP = (1 << 9),
-	CACHE_DATA_RAM_SETUP = (1 << 5),
-#endif
-	CACHE_TAG_RAM_LATENCY = (2 << 6),
-	CACHE_DATA_RAM_LATENCY = (2 << 0)
-};
-
 void reset_cpu(ulong addr)
 {
 	writel(0x1, samsung_get_base_swreset());
@@ -30,45 +21,3 @@ void enable_caches(void)
 	dcache_enable();
 }
 #endif
-
-#ifndef CONFIG_SYS_L2CACHE_OFF
-/*
- * Set L2 cache parameters
- */
-static void exynos5_set_l2cache_params(void)
-{
-	unsigned int val = 0;
-
-	asm volatile("mrc p15, 1, %0, c9, c0, 2\n" : "=r"(val));
-
-#ifndef CONFIG_EXYNOS5420
-	val |= CACHE_TAG_RAM_SETUP |
-		CACHE_DATA_RAM_SETUP |
-		CACHE_TAG_RAM_LATENCY |
-		CACHE_DATA_RAM_LATENCY;
-#else
-	val |= CACHE_TAG_RAM_LATENCY |
-		CACHE_DATA_RAM_LATENCY;
-#endif
-
-	asm volatile("mcr p15, 1, %0, c9, c0, 2\n" : : "r"(val));
-
-#ifdef CONFIG_EXYNOS5420
-	/* Read CP15 L2ACTLR value */
-	asm volatile("mrc	p15, 1, %0, c15, c0, 0" : "=r" (val));
-	/* Disable clean/evict push to external */
-	val |= (0x1 << 3);
-	/* Write new vlaue to L2ACTLR */
-	asm volatile("mcr	p15, 1, %0, c15, c0, 0" : : "r" (val));
-#endif
-}
-
-/*
- * Sets L2 cache related parameters before enabling data cache
- */
-void v7_outer_cache_enable(void)
-{
-	if (cpu_is_exynos5())
-		exynos5_set_l2cache_params();
-}
-#endif
diff --git a/arch/arm/include/asm/arch-exynos/system.h b/arch/arm/include/asm/arch-exynos/system.h
index a9fd5e6..3ffb296 100644
--- a/arch/arm/include/asm/arch-exynos/system.h
+++ b/arch/arm/include/asm/arch-exynos/system.h
@@ -37,7 +37,6 @@ 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
@@ -125,7 +124,6 @@ struct exynos5_sysreg {
 /* 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);
-- 
1.9.1

[U-Boot] [PATCH v2 02/11] Exynos542x: CPU: Power down all secondary cores

[Simon Glass]

On 3 February 2015 at 01:18, Akshay Saraswat <akshay.s@samsung.com> wrote:
> 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>
> ---
> Changes since v1:
>         - Removed unnecessary macros.
>         - Changed names of few macros for better understanding.
>         - Added MPIDR bit assignment info comment in power_down_core.
>
>  arch/arm/cpu/armv7/exynos/exynos5_setup.h |  3 ++
>  arch/arm/cpu/armv7/exynos/lowlevel_init.c | 69 ++++++++++++++++++++++++
>  arch/arm/include/asm/arch-exynos/cpu.h    |  5 ++
>  arch/arm/include/asm/arch-exynos/system.h | 87 +++++++++++++++++++++++++++++++
>  4 files changed, 164 insertions(+)

Reviewed-by: Simon Glass <sjg@chromium.org>

[U-Boot] [PATCH v2 11/11] Exynos: Fix L2 cache timings on Exynos5420 and Exynos5800

[Simon Glass]

On 3 February 2015 at 01:19, Akshay Saraswat <akshay.s@samsung.com> wrote:
> From: Doug Anderson <dianders@chromium.org>
>
> It was found that the L2 cache timings that we had before could cause
> freezes and hangs.  We should make things more robust with better
> timings.  Currently the production ChromeOS kernel applies these
> timings, but it's nice to fixup firmware too (and upstream probably
> won't take our kernel hacks).
>
> This also provides a big cleanup of the L2 cache init code avoiding
> some duplication.  The way things used to work:
> * low_power_start() was installed by the SPL (both at boot and resume
>   time) and left resident in iRAM for the kernel to use when bringing
>   up additional CPUs.  It used configure_l2_ctlr() and
>   configure_l2_actlr() when it detected it was on an A15.  This was
>   needed (despite the L2 cache registers being shared among all A15s)
>   because we might have been the first man in after the whole A15
>   cluster was shutdown.
> * secondary_cores_configure() was called on at boot time and at resume
>   time.  Strangely this called configure_l2_ctlr() but not
>   configure_l2_actlr() which was almost certainly wrong.  Given that
>   we'll call both (see next bullet) later in the boot process it
>   didn't matter for normal boot, but I guess this is how L2 cache
>   settings got set on 5420/5800 (but not 5250?) at resume time.
> * exynos5_set_l2cache_params() was called as part of cache enablement.
>   This should happen at boot time (normally in the SPL except for USB
>   boot where it happens in main U-Boot).
>
> Note that the old code wasn't setting ECC/parity in the cache
> enablement code but we happened to get it anyway because we'd call
> secondary_cores_configure() at boot time.  For resume time we'd get it
> anyway when the 2nd A15 core came up.
>
> Let's make this a whole lot simpler.  Now we always set these
> parameters in the same place for all boots and use the same code for
> setting up secondary CPUs.
>
> Intended net effects of this change (other than cleanup):
> * Timings go from before:
>     data: 0 cycle setup, 3 cycles (0x2) latency
>     tag:  0 cycle setup, 3 cycles (0x2) latency
>   after:
>     data: 1 cycle setup, 4 cycles (0x3) latency
>     tag:  1 cycle setup, 4 cycles (0x3) latency
> * L2ACTLR is properly initted on 5420/5800 in all cases.
>
> One note is that we're still relying on luck to keep low_power_start()
> working.  The compiler is being nice and not storing anything on the
> stack.
>
> Another note is that on its own this patch won't help to fix cache
> settings in an RW U-Boot update where we still have the RO SPL.  The
> plan for that is:
> * Have RW U-Boot re-init the cache right before calling the kernel
>   (after it has turned the L2 cache off).  This is why the functions
>   are in a header file instead of lowlevel_init.c.
>
> * Have the kernel save the L2 cache settings of the boot CPU and apply
>   them to all other CPUs.  We get a little lucky here because the old
>   code was using "|=" to modify the registers and all of the bits that
>   it's setting are also present in the new settings (!).  That means
>   that when the 2nd CPU in the A15 cluster comes up it doesn't
>   actually mess up the settings of the 1st CPU in the A15 cluster.  An
>   alternative option is to have the kernel write its own
>   low_power_start() code.
>
> Signed-off-by: Doug Anderson <dianders@chromium.org>
> Signed-off-by: Akshay Saraswat <akshay.s@samsung.com>
> ---
> Changes since v1:
>         - Fixed compilation error for snow build.
>
>  arch/arm/cpu/armv7/exynos/common_setup.h  | 55 +++++++++++++++++++++++++++++++
>  arch/arm/cpu/armv7/exynos/lowlevel_init.c | 55 +++++++++----------------------
>  arch/arm/cpu/armv7/exynos/soc.c           | 51 ----------------------------
>  arch/arm/include/asm/arch-exynos/system.h |  2 --
>  4 files changed, 70 insertions(+), 93 deletions(-)

Reviewed-by: Simon Glass <sjg@chromium.org>

[U-Boot] [PATCH v2 07/11] Exynos542x: cache: Disable clean/evict push to external

[Minkyu Kang]

Hi,

On 03/02/15 17:18, Akshay Saraswat wrote:
> L2 Auxiliary Control Register provides configuration
> and control options for the L2 memory system. Bit 3
> of L2ACTLR stands for clean/evict push to external.
> Setting bit 3 disables clean/evict which is what
> this patch intends to do.
> 
> Signed-off-by: Akshay Saraswat <akshay.s@samsung.com>
> Reviewed-by: Simon Glass <sjg@chromium.org>
> Tested-by: Simon Glass <sjg@chromium.org>
> ---
> Changes since v1:
> 	- Added Reviewed-by & Tested-by.
> 
>  arch/arm/cpu/armv7/exynos/soc.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/arch/arm/cpu/armv7/exynos/soc.c b/arch/arm/cpu/armv7/exynos/soc.c
> index 8c7d7d8..7268b9b 100644
> --- a/arch/arm/cpu/armv7/exynos/soc.c
> +++ b/arch/arm/cpu/armv7/exynos/soc.c
> @@ -45,6 +45,15 @@ static void exynos5_set_l2cache_params(void)
>  		CACHE_DATA_RAM_LATENCY;
>  
>  	asm volatile("mcr p15, 1, %0, c9, c0, 2\n" : : "r"(val));
> +
> +#ifdef CONFIG_EXYNOS5420

I think you can use proid_is.. instead of ifdef

> +	/* Read CP15 L2ACTLR value */
> +	asm volatile("mrc	p15, 1, %0, c15, c0, 0" : "=r" (val));
> +	/* Disable clean/evict push to external */
> +	val |= (0x1 << 3);
> +	/* Write new vlaue to L2ACTLR */
> +	asm volatile("mcr	p15, 1, %0, c15, c0, 0" : : "r" (val));
> +#endif
>  }
>  
>  /*
> 

Thanks,
Minkyu Kang.

[U-Boot] [PATCH v2 08/11] Exynos542x: add L2 control register configuration

[Minkyu Kang]

Hi,

On 03/02/15 17:18, Akshay Saraswat wrote:
> This patch does 3 things:
> 1. Enables ECC by setting 21st bit of L2CTLR.
> 2. Restore data and tag RAM latencies to 3 cycles because iROM sets
>    0x3000400 L2CTLR value during switching.
> 3. Disable clean/evict push to external by setting 3rd bit of L2ACTLR.
>    We need to restore this here due to switching.
> 
> Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
> Signed-off-by: Akshay Saraswat <akshay.s@samsung.com>
> Reviewed-by: Simon Glass <sjg@chromium.org>
> Tested-by: Simon Glass <sjg@chromium.org>
> ---
> Changes since v1:
> 	- Added Reviewed-by & Tested-by.
> 
>  arch/arm/cpu/armv7/exynos/lowlevel_init.c | 53 +++++++++++++++++++++++--------
>  arch/arm/cpu/armv7/exynos/soc.c           |  7 ++++
>  2 files changed, 46 insertions(+), 14 deletions(-)
> 
> diff --git a/arch/arm/cpu/armv7/exynos/lowlevel_init.c b/arch/arm/cpu/armv7/exynos/lowlevel_init.c
> index 1c70e54..9892e6b 100644
> --- a/arch/arm/cpu/armv7/exynos/lowlevel_init.c
> +++ b/arch/arm/cpu/armv7/exynos/lowlevel_init.c
> @@ -68,24 +68,40 @@ static void enable_smp(void)
>  }
>  
>  /*
> + * Enable ECC by setting L2CTLR[21].
> + * Set L2CTLR[7] to make tag ram latency 3 cycles and
> + * set L2CTLR[1] to make data ram latency 3 cycles.
> + * We need to make RAM latency of 3 cycles here because cores
> + * power ON and OFF while switching. And everytime a core powers
> + * ON, iROM provides it a default L2CTLR value 0x400 which stands
> + * for TAG RAM setup of 1 cycle. Hence, we face a need of
> + * restoring data and tag latency values.
> + */
> +static void configure_l2_ctlr(void)
> +{
> +	uint32_t val;
> +
> +	mrc_l2_ctlr(val);
> +	val |= (1 << 21);
> +	val |= (1 << 7);
> +	val |= (1 << 1);
> +	mcr_l2_ctlr(val);
> +}
> +
> +/*
>   * Set L2ACTLR[7] to reissue any memory transaction in the L2 that has been
>   * stalled for 1024 cycles to verify that its hazard condition still exists.
> + * Disable clean/evict push to external by setting L2ACTLR[3].
>   */
> -static void configure_l2actlr(void)
> +static void configure_l2_actlr(void)
>  {
>  	uint32_t val;
>  
> -	/* Read MIDR for Primary Part Number */
> -	mrc_midr(val);
> -	val = (val >> 4);
> -	val &= 0xf;
> -
> -	/* L2ACTLR[7]: Enable hazard detect timeout for A15 */
> -	if (val == 0xf) {
> -		mrc_l2_aux_ctlr(val);
> -		val |= (1 << 7);
> -		mcr_l2_aux_ctlr(val);
> -	}
> +	mrc_l2_aux_ctlr(val);
> +	val |= (1 << 27);
> +	val |= (1 << 7);
> +	val |= (1 << 3);
> +	mcr_l2_aux_ctlr(val);
>  }
>  
>  /*
> @@ -122,7 +138,16 @@ static void low_power_start(void)
>  
>  	/* Set the CPU to SVC32 mode */
>  	svc32_mode_en();
> -	configure_l2actlr();
> +
> +	/* Read MIDR for Primary Part Number */
> +	mrc_midr(val);
> +	val = (val >> 4);
> +	val &= 0xf;
> +
> +	if (val == 0xf) {
> +		configure_l2_ctlr();
> +		configure_l2_actlr();
> +	}
>  
>  	/* Invalidate L1 & TLB */
>  	val = 0x0;
> @@ -175,7 +200,7 @@ static void power_down_core(void)
>  static void secondary_cores_configure(void)
>  {
>  	/* Setup L2 cache */
> -	configure_l2actlr();
> +	configure_l2_ctlr();
>  
>  	/* Clear secondary boot iRAM base */
>  	writel(0x0, (CONFIG_EXYNOS_RELOCATE_CODE_BASE + 0x1C));
> diff --git a/arch/arm/cpu/armv7/exynos/soc.c b/arch/arm/cpu/armv7/exynos/soc.c
> index 7268b9b..ea201e7 100644
> --- a/arch/arm/cpu/armv7/exynos/soc.c
> +++ b/arch/arm/cpu/armv7/exynos/soc.c
> @@ -10,8 +10,10 @@
>  #include <asm/system.h>
>  
>  enum l2_cache_params {
> +#ifndef CONFIG_EXYNOS5420

Please don't use ifdef.

>  	CACHE_TAG_RAM_SETUP = (1 << 9),
>  	CACHE_DATA_RAM_SETUP = (1 << 5),
> +#endif
>  	CACHE_TAG_RAM_LATENCY = (2 << 6),
>  	CACHE_DATA_RAM_LATENCY = (2 << 0)
>  };
> @@ -39,10 +41,15 @@ static void exynos5_set_l2cache_params(void)
>  
>  	asm volatile("mrc p15, 1, %0, c9, c0, 2\n" : "=r"(val));
>  
> +#ifndef CONFIG_EXYNOS5420
>  	val |= CACHE_TAG_RAM_SETUP |
>  		CACHE_DATA_RAM_SETUP |
>  		CACHE_TAG_RAM_LATENCY |
>  		CACHE_DATA_RAM_LATENCY;
> +#else
> +	val |= CACHE_TAG_RAM_LATENCY |
> +		CACHE_DATA_RAM_LATENCY;
> +#endif
>  
>  	asm volatile("mcr p15, 1, %0, c9, c0, 2\n" : : "r"(val));
>  
> 

Thanks,
Minkyu Kang.