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Subject[RFC PATCH 6/7] ARM: ux500: use generic SMP spin-table routines
Date
Get rid of the ux500-specific code that implements the "holding pen"
for secondary CPUs. Use the code defined in "arch/arm/kernel/smp.c"
instead.

Note:
The original "holding pen" code for this machine used only the
bottom 4 bits of the MPIDR to identify the processor id. The
common code looks at the bottom 24 bits. The validity of this
change needs to be verified.

Signed-off-by: Alex Elder <elder@linaro.org>
---
arch/arm/mach-ux500/Makefile | 2 +-
arch/arm/mach-ux500/headsmp.S | 37 ---------------------
arch/arm/mach-ux500/platsmp.c | 72 ++---------------------------------------
3 files changed, 4 insertions(+), 107 deletions(-)
delete mode 100644 arch/arm/mach-ux500/headsmp.S

diff --git a/arch/arm/mach-ux500/Makefile b/arch/arm/mach-ux500/Makefile
index d05ba75..0308fe1 100644
--- a/arch/arm/mach-ux500/Makefile
+++ b/arch/arm/mach-ux500/Makefile
@@ -9,7 +9,7 @@ obj-$(CONFIG_MACH_MOP500) += board-mop500-sdi.o \
board-mop500-regulators.o \
board-mop500-pins.o \
board-mop500-audio.o
-obj-$(CONFIG_SMP) += platsmp.o headsmp.o
+obj-$(CONFIG_SMP) += platsmp.o
obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o

CFLAGS_hotplug.o += -march=armv7-a
diff --git a/arch/arm/mach-ux500/headsmp.S b/arch/arm/mach-ux500/headsmp.S
deleted file mode 100644
index 9cdea04..0000000
--- a/arch/arm/mach-ux500/headsmp.S
+++ /dev/null
@@ -1,37 +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>
-
-/*
- * 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 a44967f..6812aac 100644
--- a/arch/arm/mach-ux500/platsmp.c
+++ b/arch/arm/mach-ux500/platsmp.c
@@ -26,21 +26,6 @@
#include "db8500-regs.h"
#include "id.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
- * or not. This is necessary for the hotplug code to work reliably.
- */
-static void write_pen_release(int val)
-{
- pen_release = val;
- smp_wmb();
- sync_cache_w(&pen_release);
-}
-
static void __iomem *scu_base_addr(void)
{
if (cpu_is_u8500_family() || cpu_is_ux540_family())
@@ -51,57 +36,6 @@ static void __iomem *scu_base_addr(void)
return NULL;
}

-static DEFINE_SPINLOCK(boot_lock);
-
-static void ux500_secondary_init(unsigned int cpu)
-{
- /*
- * let the primary processor know we're out of the
- * pen, then head off into the C entry point
- */
- write_pen_release(-1);
-
- /*
- * Synchronise with the boot thread.
- */
- spin_lock(&boot_lock);
- spin_unlock(&boot_lock);
-}
-
-static int ux500_boot_secondary(unsigned int cpu, struct task_struct *idle)
-{
- unsigned long timeout;
-
- /*
- * set synchronisation state between this boot processor
- * and the secondary one
- */
- spin_lock(&boot_lock);
-
- /*
- * The secondary processor is waiting to be released from
- * the holding pen - release it, then wait for it to flag
- * that it has been released by resetting pen_release.
- */
- write_pen_release(cpu_logical_map(cpu));
-
- arch_send_wakeup_ipi_mask(cpumask_of(cpu));
-
- timeout = jiffies + (1 * HZ);
- while (time_before(jiffies, timeout)) {
- if (pen_release == -1)
- break;
- }
-
- /*
- * now the secondary core is starting up let it run its
- * calibrations, then wait for it to finish
- */
- spin_unlock(&boot_lock);
-
- return pen_release != -1 ? -ENOSYS : 0;
-}
-
static void __init wakeup_secondary(void)
{
void __iomem *backupram;
@@ -118,7 +52,7 @@ 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(secondary_holding_pen),
backupram + UX500_CPU1_JUMPADDR_OFFSET);

#define UX500_CPU1_WAKEMAGIC_OFFSET 0x1FF0
@@ -161,8 +95,8 @@ static void __init ux500_smp_prepare_cpus(unsigned int max_cpus)
struct smp_operations ux500_smp_ops __initdata = {
.smp_init_cpus = ux500_smp_init_cpus,
.smp_prepare_cpus = ux500_smp_prepare_cpus,
- .smp_secondary_init = ux500_secondary_init,
- .smp_boot_secondary = ux500_boot_secondary,
+ .smp_boot_secondary = smp_boot_secondary,
+ .smp_secondary_init = smp_secondary_init,
#ifdef CONFIG_HOTPLUG_CPU
.cpu_die = ux500_cpu_die,
#endif
--
1.7.9.5


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