[RFC PATCH] ARM: SMP: consolidate holding pen

* [RFC PATCH] ARM: SMP: consolidate holding pen
@ 2012-10-17 15:32 Marc Zyngier
  2012-10-17 17:18 ` Nicolas Pitre
                   ` (2 more replies)
  0 siblings, 3 replies; 4+ messages in thread
From: Marc Zyngier @ 2012-10-17 15:32 UTC (permalink / raw)
  To: linux-arm-kernel

As with other bits of the SMP code, platforms have duplicated a lot
of the RealView implementation. As an effort to slightly reduce
the clutter, make the plat-versatile version of the holding pen
a standard part of the SMP framework.

Platforms can still provide their own, but those who carried an exact
duplicate of the Realview code are switched to the common implementation.

Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: David Brown <davidb@codeaurora.org>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 arch/arm/include/asm/smp.h                     |  2 ++
 arch/arm/kernel/Makefile                       |  2 +-
 arch/arm/kernel/smp_pen.S                      | 41 ++++++++++++++++++++++++
 arch/arm/mach-exynos/Makefile                  |  2 +-
 arch/arm/mach-exynos/headsmp.S                 | 43 --------------------------
 arch/arm/mach-exynos/platsmp.c                 |  6 ++--
 arch/arm/mach-msm/Makefile                     |  2 +-
 arch/arm/mach-msm/headsmp.S                    | 41 ------------------------
 arch/arm/mach-msm/platsmp.c                    |  4 +--
 arch/arm/mach-realview/platsmp.c               |  2 +-
 arch/arm/mach-ux500/Makefile                   |  2 +-
 arch/arm/mach-ux500/headsmp.S                  | 39 -----------------------
 arch/arm/mach-ux500/platsmp.c                  |  5 +--
 arch/arm/mach-vexpress/platsmp.c               |  2 +-
 arch/arm/plat-versatile/Makefile               |  2 +-
 arch/arm/plat-versatile/headsmp.S              | 41 ------------------------
 arch/arm/plat-versatile/include/plat/platsmp.h |  1 -
 17 files changed, 54 insertions(+), 183 deletions(-)
 create mode 100644 arch/arm/kernel/smp_pen.S
 delete mode 100644 arch/arm/mach-exynos/headsmp.S
 delete mode 100644 arch/arm/mach-msm/headsmp.S
 delete mode 100644 arch/arm/mach-ux500/headsmp.S
 delete mode 100644 arch/arm/plat-versatile/headsmp.S

diff --git a/arch/arm/include/asm/smp.h b/arch/arm/include/asm/smp.h
index 2e3be16..538a3ea 100644
--- a/arch/arm/include/asm/smp.h
+++ b/arch/arm/include/asm/smp.h
@@ -72,6 +72,8 @@ struct secondary_data {
 extern struct secondary_data secondary_data;
 extern volatile int pen_release;
 
+extern void smp_pen_secondary_startup(void);
+
 extern int __cpu_disable(void);
 
 extern void __cpu_die(unsigned int cpu);
diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
index 5bbec7b..505cfc7 100644
--- a/arch/arm/kernel/Makefile
+++ b/arch/arm/kernel/Makefile
@@ -32,7 +32,7 @@ obj-$(CONFIG_ARTHUR)		+= arthur.o
 obj-$(CONFIG_ISA_DMA)		+= dma-isa.o
 obj-$(CONFIG_PCI)		+= bios32.o isa.o
 obj-$(CONFIG_ARM_CPU_SUSPEND)	+= sleep.o suspend.o
-obj-$(CONFIG_SMP)		+= smp.o smp_tlb.o
+obj-$(CONFIG_SMP)		+= smp.o smp_tlb.o smp_pen.o
 obj-$(CONFIG_HAVE_ARM_SCU)	+= smp_scu.o
 obj-$(CONFIG_HAVE_ARM_TWD)	+= smp_twd.o
 obj-$(CONFIG_ARM_ARCH_TIMER)	+= arch_timer.o
diff --git a/arch/arm/kernel/smp_pen.S b/arch/arm/kernel/smp_pen.S
new file mode 100644
index 0000000..6c81238
--- /dev/null
+++ b/arch/arm/kernel/smp_pen.S
@@ -0,0 +1,41 @@
+/*
+ *  linux/arch/arm/kernel/smp_pen.S
+ *
+ *  Copyright (c) 2003 ARM Limited
+ *  All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/linkage.h>
+#include <linux/init.h>
+
+	__CPUINIT
+
+/*
+ * Generic specific entry point for secondary CPUs.
+ * This provides a "holding pen" into which all secondary cores are held
+ * until we're ready for them to initialise.
+ */
+ENTRY(smp_pen_secondary_startup)
+	mrc	p15, 0, r0, c0, c0, 5
+	and	r0, r0, #15
+	adr	r4, 1f
+	ldmia	r4, {r5, r6}
+	sub	r4, r4, r5
+	add	r6, r6, r4
+pen:	ldr	r7, [r6]
+	cmp	r7, r0
+	bne	pen
+
+	/*
+	 * we've been released from the holding pen: secondary_stack
+	 * should now contain the SVC stack for this core
+	 */
+	b	secondary_startup
+
+	.align
+1:	.long	.
+	.long	pen_release
+ENDPROC(smp_pen_secondary_startup)
diff --git a/arch/arm/mach-exynos/Makefile b/arch/arm/mach-exynos/Makefile
index 9b58024..fc19fb9 100644
--- a/arch/arm/mach-exynos/Makefile
+++ b/arch/arm/mach-exynos/Makefile
@@ -24,7 +24,7 @@ obj-$(CONFIG_CPU_IDLE)		+= cpuidle.o
 
 obj-$(CONFIG_ARCH_EXYNOS)	+= pmu.o
 
-obj-$(CONFIG_SMP)		+= platsmp.o headsmp.o
+obj-$(CONFIG_SMP)		+= platsmp.o
 
 obj-$(CONFIG_EXYNOS4_MCT)	+= mct.o
 
diff --git a/arch/arm/mach-exynos/headsmp.S b/arch/arm/mach-exynos/headsmp.S
deleted file mode 100644
index 5364d4b..0000000
--- a/arch/arm/mach-exynos/headsmp.S
+++ /dev/null
@@ -1,43 +0,0 @@
-/*
- *  linux/arch/arm/mach-exynos4/headsmp.S
- *
- *  Cloned from linux/arch/arm/mach-realview/headsmp.S
- *
- *  Copyright (c) 2003 ARM Limited
- *  All Rights Reserved
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- */
-#include <linux/linkage.h>
-#include <linux/init.h>
-
-	__CPUINIT
-
-/*
- * exynos4 specific entry point for secondary CPUs.  This provides
- * a "holding pen" into which all secondary cores are held until we're
- * ready for them to initialise.
- */
-ENTRY(exynos4_secondary_startup)
-	mrc	p15, 0, r0, c0, c0, 5
-	and	r0, r0, #15
-	adr	r4, 1f
-	ldmia	r4, {r5, r6}
-	sub	r4, r4, r5
-	add	r6, r6, r4
-pen:	ldr	r7, [r6]
-	cmp	r7, r0
-	bne	pen
-
-	/*
-	 * we've been released from the holding pen: secondary_stack
-	 * should now contain the SVC stack for this core
-	 */
-	b	secondary_startup
-ENDPROC(exynos4_secondary_startup)
-
-	.align 2
-1:	.long	.
-	.long	pen_release
diff --git a/arch/arm/mach-exynos/platsmp.c b/arch/arm/mach-exynos/platsmp.c
index f93d820..bb758b2 100644
--- a/arch/arm/mach-exynos/platsmp.c
+++ b/arch/arm/mach-exynos/platsmp.c
@@ -34,8 +34,6 @@
 
 #include "common.h"
 
-extern void exynos4_secondary_startup(void);
-
 #define CPU1_BOOT_REG		(samsung_rev() == EXYNOS4210_REV_1_1 ? \
 				S5P_INFORM5 : S5P_VA_SYSRAM)
 
@@ -132,7 +130,7 @@ static int __cpuinit exynos_boot_secondary(unsigned int cpu, struct task_struct
 	while (time_before(jiffies, timeout)) {
 		smp_rmb();
 
-		__raw_writel(virt_to_phys(exynos4_secondary_startup),
+		__raw_writel(virt_to_phys(smp_pen_secondary_startup),
 			CPU1_BOOT_REG);
 		gic_raise_softirq(cpumask_of(cpu), 0);
 
@@ -190,7 +188,7 @@ static void __init exynos_smp_prepare_cpus(unsigned int max_cpus)
 	 * until it receives a soft interrupt, and then the
 	 * secondary CPU branches to this address.
 	 */
-	__raw_writel(virt_to_phys(exynos4_secondary_startup),
+	__raw_writel(virt_to_phys(smp_pen_secondary_startup),
 			CPU1_BOOT_REG);
 }
 
diff --git a/arch/arm/mach-msm/Makefile b/arch/arm/mach-msm/Makefile
index 17519fa..4f1c61f 100644
--- a/arch/arm/mach-msm/Makefile
+++ b/arch/arm/mach-msm/Makefile
@@ -18,7 +18,7 @@ obj-$(CONFIG_MSM_SCM) += scm.o scm-boot.o
 CFLAGS_scm.o :=$(call as-instr,.arch_extension sec,-DREQUIRES_SEC=1)
 
 obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o
-obj-$(CONFIG_SMP) += headsmp.o platsmp.o
+obj-$(CONFIG_SMP) += platsmp.o
 
 obj-$(CONFIG_MACH_TROUT) += board-trout.o board-trout-gpio.o board-trout-mmc.o devices-msm7x00.o
 obj-$(CONFIG_MACH_TROUT) += board-trout.o board-trout-gpio.o board-trout-mmc.o board-trout-panel.o devices-msm7x00.o
diff --git a/arch/arm/mach-msm/headsmp.S b/arch/arm/mach-msm/headsmp.S
deleted file mode 100644
index bcd5af2..0000000
--- a/arch/arm/mach-msm/headsmp.S
+++ /dev/null
@@ -1,41 +0,0 @@
-/*
- *  linux/arch/arm/mach-realview/headsmp.S
- *
- *  Copyright (c) 2003 ARM Limited
- *  All Rights Reserved
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- */
-#include <linux/linkage.h>
-#include <linux/init.h>
-
-	__CPUINIT
-
-/*
- * MSM specific entry point for secondary CPUs.  This provides
- * a "holding pen" into which all secondary cores are held until we're
- * ready for them to initialise.
- */
-ENTRY(msm_secondary_startup)
-	mrc	p15, 0, r0, c0, c0, 5
-	and	r0, r0, #15
-	adr	r4, 1f
-	ldmia	r4, {r5, r6}
-	sub	r4, r4, r5
-	add	r6, r6, r4
-pen:	ldr	r7, [r6]
-	cmp	r7, r0
-	bne	pen
-
-	/*
-	 * we've been released from the holding pen: secondary_stack
-	 * should now contain the SVC stack for this core
-	 */
-	b	secondary_startup
-ENDPROC(msm_secondary_startup)
-
-	.align
-1:	.long	.
-	.long	pen_release
diff --git a/arch/arm/mach-msm/platsmp.c b/arch/arm/mach-msm/platsmp.c
index 7ed69b69..b58a0ed 100644
--- a/arch/arm/mach-msm/platsmp.c
+++ b/arch/arm/mach-msm/platsmp.c
@@ -29,8 +29,6 @@
 #define SCSS_CPU1CORE_RESET 0xD80
 #define SCSS_DBG_STATUS_CORE_PWRDUP 0xE64
 
-extern void msm_secondary_startup(void);
-
 static DEFINE_SPINLOCK(boot_lock);
 
 static inline int get_core_count(void)
@@ -65,7 +63,7 @@ static void __cpuinit msm_secondary_init(unsigned int cpu)
 static __cpuinit void prepare_cold_cpu(unsigned int cpu)
 {
 	int ret;
-	ret = scm_set_boot_addr(virt_to_phys(msm_secondary_startup),
+	ret = scm_set_boot_addr(virt_to_phys(smp_pen_secondary_startup),
 				SCM_FLAG_COLDBOOT_CPU1);
 	if (ret == 0) {
 		void __iomem *sc1_base_ptr;
diff --git a/arch/arm/mach-realview/platsmp.c b/arch/arm/mach-realview/platsmp.c
index 300f706..43a8e76 100644
--- a/arch/arm/mach-realview/platsmp.c
+++ b/arch/arm/mach-realview/platsmp.c
@@ -74,7 +74,7 @@ static void __init realview_smp_prepare_cpus(unsigned int max_cpus)
 	 * until it receives a soft interrupt, and then the
 	 * secondary CPU branches to this address.
 	 */
-	__raw_writel(virt_to_phys(versatile_secondary_startup),
+	__raw_writel(virt_to_phys(smp_pen_secondary_startup),
 		     __io_address(REALVIEW_SYS_FLAGSSET));
 }
 
diff --git a/arch/arm/mach-ux500/Makefile b/arch/arm/mach-ux500/Makefile
index f24710d..7fb617b 100644
--- a/arch/arm/mach-ux500/Makefile
+++ b/arch/arm/mach-ux500/Makefile
@@ -13,5 +13,5 @@ obj-$(CONFIG_MACH_MOP500)	+= board-mop500.o board-mop500-sdi.o \
 				board-mop500-u8500uib.o \
 				board-mop500-pins.o \
 				board-mop500-audio.o
-obj-$(CONFIG_SMP)		+= platsmp.o headsmp.o
+obj-$(CONFIG_SMP)		+= platsmp.o
 obj-$(CONFIG_HOTPLUG_CPU)	+= hotplug.o
diff --git a/arch/arm/mach-ux500/headsmp.S b/arch/arm/mach-ux500/headsmp.S
deleted file mode 100644
index 08da5589..0000000
--- a/arch/arm/mach-ux500/headsmp.S
+++ /dev/null
@@ -1,39 +0,0 @@
-/*
- *  Copyright (c) 2009 ST-Ericsson
- *	This file is based  ARM Realview platform
- *  Copyright (c) 2003 ARM Limited
- *  All Rights Reserved
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- */
-#include <linux/linkage.h>
-#include <linux/init.h>
-
-	__INIT
-
-/*
- * U8500 specific entry point for secondary CPUs.
- */
-ENTRY(u8500_secondary_startup)
-	mrc	p15, 0, r0, c0, c0, 5
-	and	r0, r0, #15
-	adr	r4, 1f
-	ldmia	r4, {r5, r6}
-	sub	r4, r4, r5
-	add	r6, r6, r4
-pen:	ldr	r7, [r6]
-	cmp	r7, r0
-	bne	pen
-
-	/*
-	 * we've been released from the holding pen: secondary_stack
-	 * should now contain the SVC stack for this core
-	 */
-	b	secondary_startup
-ENDPROC(u8500_secondary_startup)
-
-	.align 2
-1:	.long	.
-	.long	pen_release
diff --git a/arch/arm/mach-ux500/platsmp.c b/arch/arm/mach-ux500/platsmp.c
index 3db7782..3d946a6 100644
--- a/arch/arm/mach-ux500/platsmp.c
+++ b/arch/arm/mach-ux500/platsmp.c
@@ -24,9 +24,6 @@
 #include <mach/hardware.h>
 #include <mach/setup.h>
 
-/* This is called from headsmp.S to wakeup the secondary core */
-extern void u8500_secondary_startup(void);
-
 /*
  * Write pen_release in a way that is guaranteed to be visible to all
  * observers, irrespective of whether they're taking part in coherency
@@ -124,7 +121,7 @@ static void __init wakeup_secondary(void)
 	 * is waiting for. This would wake up the secondary core from WFE
 	 */
 #define UX500_CPU1_JUMPADDR_OFFSET 0x1FF4
-	__raw_writel(virt_to_phys(u8500_secondary_startup),
+	__raw_writel(virt_to_phys(smp_pen_secondary_startup),
 		     backupram + UX500_CPU1_JUMPADDR_OFFSET);
 
 #define UX500_CPU1_WAKEMAGIC_OFFSET 0x1FF0
diff --git a/arch/arm/mach-vexpress/platsmp.c b/arch/arm/mach-vexpress/platsmp.c
index 7db27c8..d1b99a7 100644
--- a/arch/arm/mach-vexpress/platsmp.c
+++ b/arch/arm/mach-vexpress/platsmp.c
@@ -193,7 +193,7 @@ static void __init vexpress_smp_prepare_cpus(unsigned int max_cpus)
 	 * until it receives a soft interrupt, and then the
 	 * secondary CPU branches to this address.
 	 */
-	v2m_flags_set(virt_to_phys(versatile_secondary_startup));
+	v2m_flags_set(virt_to_phys(smp_pen_secondary_startup));
 }
 
 struct smp_operations __initdata vexpress_smp_ops = {
diff --git a/arch/arm/plat-versatile/Makefile b/arch/arm/plat-versatile/Makefile
index 74cfd94..a0f987e 100644
--- a/arch/arm/plat-versatile/Makefile
+++ b/arch/arm/plat-versatile/Makefile
@@ -5,4 +5,4 @@ obj-$(CONFIG_PLAT_VERSATILE_CLCD) += clcd.o
 obj-$(CONFIG_PLAT_VERSATILE_FPGA_IRQ) += fpga-irq.o
 obj-$(CONFIG_PLAT_VERSATILE_LEDS) += leds.o
 obj-$(CONFIG_PLAT_VERSATILE_SCHED_CLOCK) += sched-clock.o
-obj-$(CONFIG_SMP) += headsmp.o platsmp.o
+obj-$(CONFIG_SMP) += platsmp.o
diff --git a/arch/arm/plat-versatile/headsmp.S b/arch/arm/plat-versatile/headsmp.S
deleted file mode 100644
index dd703ef..0000000
--- a/arch/arm/plat-versatile/headsmp.S
+++ /dev/null
@@ -1,41 +0,0 @@
-/*
- *  linux/arch/arm/plat-versatile/headsmp.S
- *
- *  Copyright (c) 2003 ARM Limited
- *  All Rights Reserved
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- */
-#include <linux/linkage.h>
-#include <linux/init.h>
-
-	__INIT
-
-/*
- * Realview/Versatile Express specific entry point for secondary CPUs.
- * This provides a "holding pen" into which all secondary cores are held
- * until we're ready for them to initialise.
- */
-ENTRY(versatile_secondary_startup)
-	mrc	p15, 0, r0, c0, c0, 5
-	and	r0, r0, #15
-	adr	r4, 1f
-	ldmia	r4, {r5, r6}
-	sub	r4, r4, r5
-	add	r6, r6, r4
-pen:	ldr	r7, [r6]
-	cmp	r7, r0
-	bne	pen
-
-	/*
-	 * we've been released from the holding pen: secondary_stack
-	 * should now contain the SVC stack for this core
-	 */
-	b	secondary_startup
-
-	.align
-1:	.long	.
-	.long	pen_release
-ENDPROC(versatile_secondary_startup)
diff --git a/arch/arm/plat-versatile/include/plat/platsmp.h b/arch/arm/plat-versatile/include/plat/platsmp.h
index 50fb830..cb893c2 100644
--- a/arch/arm/plat-versatile/include/plat/platsmp.h
+++ b/arch/arm/plat-versatile/include/plat/platsmp.h
@@ -9,6 +9,5 @@
  * published by the Free Software Foundation.
  */
 
-extern void versatile_secondary_startup(void);
 extern void versatile_secondary_init(unsigned int cpu);
 extern int  versatile_boot_secondary(unsigned int cpu, struct task_struct *idle);
-- 
1.7.12

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