ARM: SH-Mobile: sh73a0: Secondary CPUs handle own SCU flags

When booting secondary CPUs we have used the main CPU to set up the
Snoop Control Unit flags of these CPUs. It is a cleaner approach
if every CPU takes care of its own flags. We avoid the need for
locking and the program logic is more concise. With this patch the file
headsmp-sh73a0.S is added that contains a startup vector for secondary CPUs
that sets up its own SCU flags.
Further in sh73a0_smp_prepare_cpus() we can rely on the generic ARM helper
scu_power_mode(). This is possible as we don't cross borders anymore (every
CPU handles its own flags) and need no locking. So we can throw out the
needless function modify_scu_cpu_psr().

Signed-off-by: Bastian Hecht <hechtb+renesas@gmail.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

1 files changed, 4 insertions, 26 deletions

diff --git a/arch/arm/mach-shmobile/smp-sh73a0.c b/arch/arm/mach-shmobile/smp-sh73a0.c
index 5c5bcb595350..430b44ea85f2 100644
--- a/arch/arm/mach-shmobile/smp-sh73a0.c
+++ b/arch/arm/mach-shmobile/smp-sh73a0.c
@@ -41,9 +41,6 @@ static void __iomem *scu_base_addr(void)
 	return (void __iomem *)0xf0000000;
 }
 
-static DEFINE_SPINLOCK(scu_lock);
-static unsigned long tmp;
-
 #ifdef CONFIG_HAVE_ARM_TWD
 static DEFINE_TWD_LOCAL_TIMER(twd_local_timer, 0xf0000600, 29);
 void __init sh73a0_register_twd(void)
@@ -52,20 +49,6 @@ void __init sh73a0_register_twd(void)
 }
 #endif
 
-static void modify_scu_cpu_psr(unsigned long set, unsigned long clr)
-{
-	void __iomem *scu_base = scu_base_addr();
-
-	spin_lock(&scu_lock);
-	tmp = __raw_readl(scu_base + 8);
-	tmp &= ~clr;
-	tmp |= set;
-	spin_unlock(&scu_lock);
-
-	/* disable cache coherency after releasing the lock */
-	__raw_writel(tmp, scu_base + 8);
-}
-
 static unsigned int __init sh73a0_get_core_count(void)
 {
 	void __iomem *scu_base = scu_base_addr();
@@ -82,9 +65,6 @@ static int __cpuinit sh73a0_boot_secondary(unsigned int cpu, struct task_struct
 {
 	cpu = cpu_logical_map(cpu);
 
-	/* enable cache coherency */
-	modify_scu_cpu_psr(0, 3 << (cpu * 8));
-
 	if (((__raw_readl(PSTR) >> (4 * cpu)) & 3) == 3)
 		__raw_writel(1 << cpu, WUPCR);	/* wake up */
 	else
@@ -95,16 +75,14 @@ static int __cpuinit sh73a0_boot_secondary(unsigned int cpu, struct task_struct
 
 static void __init sh73a0_smp_prepare_cpus(unsigned int max_cpus)
 {
-	int cpu = cpu_logical_map(0);
-
 	scu_enable(scu_base_addr());
 
-	/* Map the reset vector (in headsmp.S) */
+	/* Map the reset vector (in headsmp-sh73a0.S) */
 	__raw_writel(0, APARMBAREA);      /* 4k */
-	__raw_writel(__pa(shmobile_secondary_vector), SBAR);
+	__raw_writel(__pa(sh73a0_secondary_vector), SBAR);
 
-	/* enable cache coherency on CPU0 */
-	modify_scu_cpu_psr(0, 3 << (cpu * 8));
+	/* enable cache coherency on booting CPU */
+	scu_power_mode(scu_base_addr(), SCU_PM_NORMAL);
 }
 
 static void __init sh73a0_smp_init_cpus(void)