[cns3xxx]: fix ncores for single-core systems.

 
For cns3xxx SCU_CONFIGURATION always shows multipe cores but SCU_CPU_STATUS
shows which ones are active.
 
 
Signed-off-by: Tim Harvey <tharvey@gateworks.com>


git-svn-id: svn://svn.openwrt.org/openwrt/trunk@33566 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 109 insertions, 0 deletions

diff --git a/target/linux/cns3xxx/patches-3.3/450-smp_ncores.patch b/target/linux/cns3xxx/patches-3.3/450-smp_ncores.patch
new file mode 100644
index 0000000000..c942a9b7e3
--- /dev/null
+++ b/target/linux/cns3xxx/patches-3.3/450-smp_ncores.patch
@@ -0,0 +1,109 @@
+--- a/arch/arm/mach-cns3xxx/platsmp.c
++++ b/arch/arm/mach-cns3xxx/platsmp.c
+@@ -1,18 +1,17 @@
+-/* linux/arch/arm/mach-cns3xxx/platsmp.c
++/*
++ *  linux/arch/arm/mach-cns3xxx/platsmp.c
+  *
+- * Copyright 2011 Gateworks Corporation
++ *  Copyright (C) 2002 ARM Ltd.
++ *  Copyright 2012 Gateworks Corporation
+  *		   Chris Lang <clang@gateworks.com>
++ *         Tim Harvey <tharvey@gateworks.com>
+  *
+- * Cloned from linux/arch/arm/mach-vexpress/platsmp.c
+- *
+- *  Copyright (C) 2002 ARM Ltd.
+  *  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/init.h>
+ #include <linux/errno.h>
+ #include <linux/delay.h>
+@@ -30,11 +29,13 @@
+ 
+ extern void cns3xxx_secondary_startup(void);
+ 
++#define SCU_CPU_STATUS 0x08
++static void __iomem *scu_base;
++
+ /*
+  * control for which core is the next to come out of the secondary
+  * boot "holding pen"
+  */
+-
+ volatile int __cpuinitdata pen_release = -1;
+ 
+ /*
+@@ -50,11 +51,6 @@ static void write_pen_release(int val)
+ 	outer_clean_range(__pa(&pen_release), __pa(&pen_release + 1));
+ }
+ 
+-static void __iomem *scu_base_addr(void)
+-{
+-	return (void __iomem *)(CNS3XXX_TC11MP_SCU_BASE_VIRT);
+-}
+-
+ static DEFINE_SPINLOCK(boot_lock);
+ 
+ void __cpuinit platform_secondary_init(unsigned int cpu)
+@@ -128,25 +124,24 @@ int __cpuinit boot_secondary(unsigned in
+  * 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;
++	unsigned int status;
+ 
+-	ncores = scu_base ? scu_get_core_count(scu_base) : 1;
++	scu_base = (void __iomem *) CNS3XXX_TC11MP_SCU_BASE_VIRT;
+ 
+-	/* sanity check */
+-	if (ncores > NR_CPUS) {
+-		printk(KERN_WARNING
+-		       "cns3xxx: no. of cores (%d) greater than configured "
+-		       "maximum of %d - clipping\n",
+-		       ncores, NR_CPUS);
+-		ncores = NR_CPUS;
++	/* for CNS3xxx SCU_CPU_STATUS must be examined instead of SCU_CONFIGURATION
++	 * used in scu_get_core_count
++	 */
++	status = __raw_readl(scu_base + SCU_CPU_STATUS);
++	for (i = 0; i < NR_CPUS+1; i++) {
++		if (((status >> (i*2)) & 0x3) == 0)
++			set_cpu_possible(i, true);
++		else
++			break;
+ 	}
+-
+-	for (i = 0; i < ncores; i++)
+-		set_cpu_possible(i, true);
++	ncores = i;
+ 
+ 	set_smp_cross_call(gic_raise_softirq);
+ }
+@@ -159,10 +154,14 @@ void __init platform_smp_prepare_cpus(un
+ 	 * Initialise the present map, which describes the set of CPUs
+ 	 * actually populated at the present time.
+ 	 */
+-	for (i = 0; i < max_cpus; i++)
++	for (i = 0; i < max_cpus; i++) {
+ 		set_cpu_present(i, true);
++	}
+ 
+-	scu_enable(scu_base_addr());
++	/*
++	 * enable SCU
++	 */
++	scu_enable(scu_base);
+ 
+ 	/*
+ 	 * Write the address of secondary startup into the