[PATCH 3/8] ARM: VExpress: Switch to generic SCU routines

Anton Vorontsov
2010-11-30T17:17:01Z

This shrinks platform-specific code quite a bit.

Signed-off-by: Anton Vorontsov <avorontsov@mvista.com>
---
arch/arm/mach-vexpress/Makefile | 2 +-
arch/arm/mach-vexpress/headsmp.S | 39 ----------
arch/arm/mach-vexpress/platsmp.c | 150 ++++----------------------------------
3 files changed, 15 insertions(+), 176 deletions(-)
delete mode 100644 arch/arm/mach-vexpress/headsmp.S

diff --git a/arch/arm/mach-vexpress/Makefile b/arch/arm/mach-vexpress/Makefile
index 1b71b77..6533d11 100644
--- a/arch/arm/mach-vexpress/Makefile
+++ b/arch/arm/mach-vexpress/Makefile
@@ -4,5 +4,5 @@

obj-y := v2m.o
obj-$(CONFIG_ARCH_VEXPRESS_CA9X4) += ct-ca9x4.o
-obj-$(CONFIG_SMP) += platsmp.o headsmp.o
+obj-$(CONFIG_SMP) += platsmp.o
obj-$(CONFIG_LOCAL_TIMERS) += localtimer.o
diff --git a/arch/arm/mach-vexpress/headsmp.S b/arch/arm/mach-vexpress/headsmp.S
deleted file mode 100644
index 8a78ff6..0000000
--- a/arch/arm/mach-vexpress/headsmp.S
+++ /dev/null
@@ -1,39 +0,0 @@
-/*
- * linux/arch/arm/mach-vexpress/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
-
-/*
- * 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(vexpress_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-vexpress/platsmp.c b/arch/arm/mach-vexpress/platsmp.c
index 276f916..2d4146f 100644
--- a/arch/arm/mach-vexpress/platsmp.c
+++ b/arch/arm/mach-vexpress/platsmp.c
@@ -9,15 +9,9 @@
* 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 <asm/localtimer.h>
#include <asm/smp_scu.h>
#include <asm/unified.h>

@@ -27,21 +21,11 @@

#include "core.h"

-extern void vexpress_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)
{
return MMIO_P2V(A9_MPCORE_SCU);
}

-static DEFINE_SPINLOCK(boot_lock);
-
void __cpuinit platform_secondary_init(unsigned int cpu)
{
trace_hardirqs_off();
@@ -53,138 +37,32 @@ 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);
-
- /*
- * This is really belt and braces; we hold unintended secondary
- * CPUs in the holding pen until we're ready for them. However,
- * since we haven't sent them a soft interrupt, they shouldn't
- * be there.
- */
- pen_release = cpu;
- __cpuc_flush_dcache_area((void *)&pen_release, sizeof(pen_release));
- outer_clean_range(__pa(&pen_release), __pa(&pen_release + 1));
-
- /*
- * Send the secondary CPU a soft interrupt, thereby causing
- * the boot monitor to read the system wide flags register,
- * and branch to the address found there.
- */
- 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 pen_release != -1 ? -ENOSYS : 0;
+ return scu_boot_secondary(cpu, idle);
}

-/*
- * 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)
{
- void __iomem *scu_base = scu_base_addr();
- unsigned int i, ncores;
-
- ncores = scu_base ? scu_get_core_count(scu_base) : 1;
-
- /* sanity check */
- if (ncores == 0) {
- printk(KERN_ERR
- "vexpress: strange CM count of 0? Default to 1\n");
-
- ncores = 1;
- }
+ scu_init_cpus(scu_base_addr());
+}

- if (ncores > NR_CPUS) {
- printk(KERN_WARNING
- "vexpress: no. of cores (%d) greater than configured "
- "maximum of %d - clipping\n",
- ncores, NR_CPUS);
- ncores = NR_CPUS;
- }
+/* If there are more than one CPU let them know where to start. */
+static void __init smp_point_cpus(void)
+{
+ if (num_present_cpus() <= 1)
+ return;

- for (i = 0; i < ncores; i++)
- set_cpu_possible(i, true);
+ writel(~0, MMIO_P2V(V2M_SYS_FLAGSCLR));
+ writel(BSYM(virt_to_phys(scu_secondary_startup)),
+ MMIO_P2V(V2M_SYS_FLAGSSET));
}

void __init smp_prepare_cpus(unsigned int max_cpus)
{
- unsigned int ncores = num_possible_cpus();
- unsigned int cpu = smp_processor_id();
- int i;
-
- 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.
- */
- 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());
-
- /*
- * Write the address of secondary startup into the
- * system-wide flags register. The boot monitor waits
- * until it receives a soft interrupt, and then the
- * secondary CPU branches to this address.
- */
- writel(~0, MMIO_P2V(V2M_SYS_FLAGSCLR));
- writel(BSYM(virt_to_phys(vexpress_secondary_startup)),
- MMIO_P2V(V2M_SYS_FLAGSSET));
- }
+ scu_prepare_cpus(scu_base_addr(), max_cpus);
+ smp_point_cpus();
}
--
1.7.0.5