[PATCH 4/8] ARM: RealView: Switch to generic SCU routines

Anton Vorontsov
2010-11-30T17:17:03Z

This shrinks platform-specific code quite a bit.

Signed-off-by: Anton Vorontsov <avorontsov@mvista.com>
---
arch/arm/mach-realview/Makefile | 2 +-
arch/arm/mach-realview/headsmp.S | 39 ---------
arch/arm/mach-realview/hotplug.c | 5 +-
arch/arm/mach-realview/platsmp.c | 161 +++-----------------------------------
4 files changed, 14 insertions(+), 193 deletions(-)
delete mode 100644 arch/arm/mach-realview/headsmp.S

diff --git a/arch/arm/mach-realview/Makefile b/arch/arm/mach-realview/Makefile
index a01b76b..d456163 100644
--- a/arch/arm/mach-realview/Makefile
+++ b/arch/arm/mach-realview/Makefile
@@ -8,6 +8,6 @@ obj-$(CONFIG_MACH_REALVIEW_PB11MP) += realview_pb11mp.o
obj-$(CONFIG_MACH_REALVIEW_PB1176) += realview_pb1176.o
obj-$(CONFIG_MACH_REALVIEW_PBA8) += realview_pba8.o
obj-$(CONFIG_MACH_REALVIEW_PBX) += realview_pbx.o
-obj-$(CONFIG_SMP) += platsmp.o headsmp.o
+obj-$(CONFIG_SMP) += platsmp.o
obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o
obj-$(CONFIG_LOCAL_TIMERS) += localtimer.o
diff --git a/arch/arm/mach-realview/headsmp.S b/arch/arm/mach-realview/headsmp.S
deleted file mode 100644
index 4075473..0000000
--- a/arch/arm/mach-realview/headsmp.S
+++ /dev/null
@@ -1,39 +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>
-
- __INIT
-
-/*
- * Realview 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(realview_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
-
-1: .long .
- .long pen_release
diff --git a/arch/arm/mach-realview/hotplug.c b/arch/arm/mach-realview/hotplug.c
index e06572e..0261785 100644
--- a/arch/arm/mach-realview/hotplug.c
+++ b/arch/arm/mach-realview/hotplug.c
@@ -12,10 +12,9 @@
#include <linux/errno.h>
#include <linux/smp.h>

+#include <asm/smp_scu.h>
#include <asm/cacheflush.h>

-extern volatile int pen_release;
-
static inline void cpu_enter_lowpower(void)
{
unsigned int v;
@@ -69,7 +68,7 @@ static inline void platform_do_lowpower(unsigned int cpu)
:
: "memory", "cc");

- if (pen_release == cpu) {
+ if (scu_pen_release == cpu) {
/*
* OK, proper wakeup, we're done
*/
diff --git a/arch/arm/mach-realview/platsmp.c b/arch/arm/mach-realview/platsmp.c
index af3d909..3c1000b 100644
--- a/arch/arm/mach-realview/platsmp.c
+++ b/arch/arm/mach-realview/platsmp.c
@@ -9,17 +9,11 @@
* published by the Free Software Foundation.
*/
#include <linux/init.h>
-#include <linux/errno.h>
-#include <linux/delay.h>
-#include <linux/device.h>
-#include <linux/jiffies.h>
#include <linux/smp.h>
#include <linux/io.h>

-#include <asm/cacheflush.h>
#include <mach/hardware.h>
#include <asm/mach-types.h>
-#include <asm/localtimer.h>
#include <asm/unified.h>

#include <mach/board-eb.h>
@@ -29,14 +23,6 @@

#include "core.h"

-extern void realview_secondary_startup(void);
-
-/*
- * control for which core is the next to come out of the secondary
- * boot "holding pen"
- */
-volatile int __cpuinitdata pen_release = -1;
-
static void __iomem *scu_base_addr(void)
{
if (machine_is_realview_eb_mp())
@@ -50,16 +36,6 @@ static void __iomem *scu_base_addr(void)
return (void __iomem *)0;
}

-static inline unsigned int get_core_count(void)
-{
- void __iomem *scu_base = scu_base_addr();
- if (scu_base)
- return scu_get_core_count(scu_base);
- return 1;
-}
-
-static DEFINE_SPINLOCK(boot_lock);
-
void __cpuinit platform_secondary_init(unsigned int cpu)
{
trace_hardirqs_off();
@@ -71,151 +47,36 @@ void __cpuinit platform_secondary_init(unsigned int cpu)
*/
gic_cpu_init(0, gic_cpu_base_addr);

- /*
- * let the primary processor know we're out of the
- * pen, then head off into the C entry point
- */
- pen_release = -1;
- smp_wmb();
-
- /*
- * Synchronise with the boot thread.
- */
- spin_lock(&boot_lock);
- spin_unlock(&boot_lock);
+ scu_secondary_init(cpu);
}

int __cpuinit 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.
- *
- * Note that "pen_release" is the hardware CPU ID, whereas
- * "cpu" is Linux's internal ID.
- */
- pen_release = cpu;
- flush_cache_all();
-
- /*
- * XXX
- *
- * This is a later addition to the booting protocol: the
- * bootMonitor now puts secondary cores into WFI, so
- * poke_milo() no longer gets the cores moving; we need
- * to send a soft interrupt to wake the secondary core.
- * Use smp_cross_call() for this, since there's little
- * point duplicating the code here
- */
- smp_cross_call(cpumask_of(cpu), 1);
-
- timeout = jiffies + (1 * HZ);
- while (time_before(jiffies, timeout)) {
- smp_rmb();
- if (pen_release == -1)
- break;
-
- udelay(10);
- }
-
- /*
- * now the secondary core is starting up let it run its
- * calibrations, then wait for it to finish
- */
- spin_unlock(&boot_lock);
+ return scu_boot_secondary(cpu, idle);
+}

- return pen_release != -1 ? -ENOSYS : 0;
+void __init smp_init_cpus(void)
+{
+ scu_init_cpus(scu_base_addr());
}

static void __init poke_milo(void)
{
- /* nobody is to be released from the pen yet */
- pen_release = -1;
-
+ if (num_present_cpus() <= 1)
+ return;
/*
* Write the address of secondary startup into the system-wide flags
* register. The BootMonitor waits for this register to become
* non-zero.
*/
- __raw_writel(BSYM(virt_to_phys(realview_secondary_startup)),
+ __raw_writel(BSYM(virt_to_phys(scu_secondary_startup)),
__io_address(REALVIEW_SYS_FLAGSSET));

mb();
}

-/*
- * Initialise the CPU possible map early - this describes the CPUs
- * which may be present or become present in the system.
- */
-void __init smp_init_cpus(void)
-{
- unsigned int i, ncores = get_core_count();
-
- for (i = 0; i < ncores; i++)
- set_cpu_possible(i, true);
-}
-
void __init smp_prepare_cpus(unsigned int max_cpus)
{
- unsigned int ncores = get_core_count();
- unsigned int cpu = smp_processor_id();
- int i;
-
- /* sanity check */
- if (ncores == 0) {
- printk(KERN_ERR
- "Realview: strange CM count of 0? Default to 1\n");
-
- ncores = 1;
- }
-
- if (ncores > NR_CPUS) {
- printk(KERN_WARNING
- "Realview: no. of cores (%d) greater than configured "
- "maximum of %d - clipping\n",
- ncores, NR_CPUS);
- ncores = NR_CPUS;
- }
-
- smp_store_cpu_info(cpu);
-
- /*
- * are we trying to boot more cores than exist?
- */
- if (max_cpus > ncores)
- max_cpus = ncores;
-
- /*
- * Initialise the present map, which describes the set of CPUs
- * actually populated at the present time.
- */
- for (i = 0; i < max_cpus; i++)
- set_cpu_present(i, true);
-
- /*
- * Initialise the SCU if there are more than one CPU and let
- * them know where to start. Note that, on modern versions of
- * MILO, the "poke" doesn't actually do anything until each
- * individual core is sent a soft interrupt to get it out of
- * WFI
- */
- if (max_cpus > 1) {
- /*
- * Enable the local timer or broadcast device for the
- * boot CPU, but only if we have more than one CPU.
- */
- percpu_timer_setup();
-
- scu_enable(scu_base_addr());
- poke_milo();
- }
+ scu_prepare_cpus(scu_base_addr(), max_cpus);
+ poke_milo();
}
--
1.7.0.5