[PATCH V5 5/5] arm: mvebu: Added SMP support for Armada XP

On 11/21/2012 11:41 AM, Will Deacon wrote:

On Tue, Nov 20, 2012 at 09:15:49PM +0000, Gregory CLEMENT wrote:

quoted

From: Yehuda Yitschak <redacted>

1. added smp init functions in platsmp.c
2. added secondary cpu entry point in headsmp.S
3. added hotplog initial support in hotplug.c

hotplug

quoted

4. added SMP support for PJ4B cpu

Again, I think the commit message could probably be improved from a numbered
list...

quoted

Signed-off-by: Yehuda Yitschak <redacted>
Signed-off-by: Gregory CLEMENT <redacted>
---
 arch/arm/configs/mvebu_defconfig    |    3 +
 arch/arm/mach-mvebu/Kconfig         |    1 +
 arch/arm/mach-mvebu/Makefile        |    2 +
 arch/arm/mach-mvebu/armada-370-xp.c |    3 +
 arch/arm/mach-mvebu/common.h        |    3 +
 arch/arm/mach-mvebu/headsmp.S       |   50 +++++++++++++++
 arch/arm/mach-mvebu/hotplug.c       |   30 +++++++++
 arch/arm/mach-mvebu/platsmp.c       |  121 +++++++++++++++++++++++++++++++++++
 8 files changed, 213 insertions(+)
 create mode 100644 arch/arm/mach-mvebu/headsmp.S
 create mode 100644 arch/arm/mach-mvebu/hotplug.c
 create mode 100644 arch/arm/mach-mvebu/platsmp.c

diff --git a/arch/arm/configs/mvebu_defconfig b/arch/arm/configs/mvebu_defconfig
index 3458752..da598d3 100644
--- a/arch/arm/configs/mvebu_defconfig
+++ b/arch/arm/configs/mvebu_defconfig

@@ -12,6 +12,9 @@ CONFIG_ARCH_MVEBU=y
 CONFIG_MACH_ARMADA_370=y
 CONFIG_MACH_ARMADA_XP=y
 # CONFIG_CACHE_L2X0 is not set
+# CONFIG_SWP_EMULATE is not set
+CONFIG_SMP=y
+# CONFIG_LOCAL_TIMERS is not set
 CONFIG_AEABI=y
 CONFIG_HIGHMEM=y
 # CONFIG_COMPACTION is not set

diff --git a/arch/arm/mach-mvebu/Kconfig b/arch/arm/mach-mvebu/Kconfig
index f4c3bf8..c934e1d 100644
--- a/arch/arm/mach-mvebu/Kconfig
+++ b/arch/arm/mach-mvebu/Kconfig

@@ -21,6 +21,7 @@ menu "Marvell SOC with device tree"
 config MACH_ARMADA_370_XP
 	bool
 	select ARMADA_370_XP_TIMER
+	select HAVE_SMP
 	select CPU_PJ4B
 
 config MACH_ARMADA_370

diff --git a/arch/arm/mach-mvebu/Makefile b/arch/arm/mach-mvebu/Makefile
index 2e3ec11..5dcb369 100644
--- a/arch/arm/mach-mvebu/Makefile
+++ b/arch/arm/mach-mvebu/Makefile

@@ -3,3 +3,5 @@ ccflags-$(CONFIG_ARCH_MULTIPLATFORM) := -I$(srctree)/$(src)/include \
 
 obj-y += system-controller.o
 obj-$(CONFIG_MACH_ARMADA_370_XP) += armada-370-xp.o irq-armada-370-xp.o addr-map.o coherency.o coherency_ll.o pmsu.o
+obj-$(CONFIG_SMP)                += platsmp.o headsmp.o
+obj-$(CONFIG_HOTPLUG_CPU)        += hotplug.o

diff --git a/arch/arm/mach-mvebu/armada-370-xp.c b/arch/arm/mach-mvebu/armada-370-xp.c
index 3292d6d..472e70f 100644
--- a/arch/arm/mach-mvebu/armada-370-xp.c
+++ b/arch/arm/mach-mvebu/armada-370-xp.c

@@ -23,6 +23,7 @@
 #include <asm/mach/time.h>
 #include "armada-370-xp.h"
 #include "common.h"
+#include "coherency.h"
 
 static struct map_desc armada_370_xp_io_desc[] __initdata = {
 	{

@@ -51,6 +52,7 @@ struct sys_timer armada_370_xp_timer = {
 static void __init armada_370_xp_dt_init(void)
 {
 	of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
+	coherency_init();
 }
 
 static const char * const armada_370_xp_dt_board_dt_compat[] = {

@@ -60,6 +62,7 @@ static const char * const armada_370_xp_dt_board_dt_compat[] = {
 };
 
 DT_MACHINE_START(ARMADA_XP_DT, "Marvell Aramada 370/XP (Device Tree)")
+	.smp		= smp_ops(armada_xp_smp_ops),
 	.init_machine	= armada_370_xp_dt_init,
 	.map_io		= armada_370_xp_map_io,
 	.init_irq	= armada_370_xp_init_irq,

diff --git a/arch/arm/mach-mvebu/common.h b/arch/arm/mach-mvebu/common.h
index b5cd7e7..b711869 100644
--- a/arch/arm/mach-mvebu/common.h
+++ b/arch/arm/mach-mvebu/common.h

@@ -20,7 +20,10 @@ void mvebu_restart(char mode, const char *cmd);
 void armada_370_xp_init_irq(void);
 void armada_370_xp_handle_irq(struct pt_regs *regs);
 
+void armada_xp_cpu_die(unsigned int cpu);
 
 int armada_370_xp_coherency_init(void);
 int armada_370_xp_pmsu_init(void);
+void armada_xp_secondary_startup(void);
+extern struct smp_operations armada_xp_smp_ops;
 #endif

diff --git a/arch/arm/mach-mvebu/headsmp.S b/arch/arm/mach-mvebu/headsmp.S
new file mode 100644
index 0000000..994eecc
--- /dev/null
+++ b/arch/arm/mach-mvebu/headsmp.S

@@ -0,0 +1,50 @@
+/*
+ * SMP support: Entry point for secondary CPUs
+ *
+ * Copyright (C) 2012 Marvell
+ *
+ * Yehuda Yitschak <yehuday@marvell.com>
+ * Gregory CLEMENT <gregory.clement@free-electrons.com>
+ * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2.  This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ *
+ * This file implements the assembly entry point for secondary CPUs in
+ * an SMP kernel. The only thing we need to do is to add the CPU to
+ * the coherency fabric by writing to 2 registers. Currently the base
+ * register addresses are hard coded due to the early initialisation
+ * problems.
+ */
+
+#include <linux/linkage.h>
+#include <linux/init.h>
+
+/*
+ * At this stage the secondary CPUs don't have acces yet to the MMU, so
+ * we have to provide physical addresses
+ */
+#define ARMADA_XP_CFB_BASE	     0xD0020200
+
+	__CPUINIT
+
+/*
+ * Armada XP specific entry point for secondary CPUs.
+ * We add the CPU to the coherency fabric and then jump to secondary
+ * startup
+ */
+ENTRY(armada_xp_secondary_startup)
+
+	/* Read CPU id */
+ 	mrc     p15, 0, r1, c0, c0, 5
+	and     r1, r1, #0xF
+
+	/* Add CPU to coherency fabric */
+	ldr     r0, = ARMADA_XP_CFB_BASE
+	mov	lr, pc
+
+	b	ll_set_cpu_coherent
+	b	secondary_startup

Why didn't you use my adr suggestion here?

Because when I used BSYM(secondary_startup), I get the following
message during compilation:

Error: undefined symbol secondary_startup used as an immediate value

And I didn't want to miss the merge window for something which could be
fixed during the v3.8-rc1 if needed.

Will

-- 
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com