diff options
| author | Magnus Damm <damm@opensource.se> | 2013-07-31 16:07:49 +0900 |
|---|---|---|
| committer | Simon Horman <horms+renesas@verge.net.au> | 2013-08-06 18:07:25 +0900 |
| commit | e7b1c96384181d690950530f5a64167965226744 (patch) | |
| tree | 0e5a11ca08b9e0816fc95c09b0657764428efb73 /arch/arm/mach-shmobile/platsmp-scu.c | |
| parent | 0da60225dee270a4a4b86c08509e772e78961b82 (diff) | |
ARM: shmobile: Add shared SCU CPU Hotplug code
Add CPU Hotplug functions for SCU equipped mach-shmobile SoCs.
The functions shmobile_smp_scu_cpu_die() together with
shmobile_smp_scu_cpu_kill() perform basic shutdown and
allows checking of shutdown status. These are written
to work together with SMP boot code in headsmp-scu.S.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Diffstat (limited to 'arch/arm/mach-shmobile/platsmp-scu.c')
| -rw-r--r-- | arch/arm/mach-shmobile/platsmp-scu.c | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/arch/arm/mach-shmobile/platsmp-scu.c b/arch/arm/mach-shmobile/platsmp-scu.c index 8f478e4d4964..7a0c066df686 100644 --- a/arch/arm/mach-shmobile/platsmp-scu.c +++ b/arch/arm/mach-shmobile/platsmp-scu.c @@ -7,9 +7,11 @@ * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ +#include <linux/delay.h> #include <linux/init.h> #include <linux/io.h> #include <linux/smp.h> +#include <asm/cacheflush.h> #include <asm/smp_plat.h> #include <asm/smp_scu.h> #include <mach/common.h> @@ -29,3 +31,46 @@ int shmobile_smp_scu_boot_secondary(unsigned int cpu, struct task_struct *idle) /* do nothing for now */ return 0; } + +#ifdef CONFIG_HOTPLUG_CPU +void shmobile_smp_scu_cpu_die(unsigned int cpu) +{ + dsb(); + flush_cache_all(); + + /* disable cache coherency */ + scu_power_mode(shmobile_scu_base, SCU_PM_POWEROFF); + + /* Endless loop until reset */ + while (1) + cpu_do_idle(); +} + +static int shmobile_smp_scu_psr_core_disabled(int cpu) +{ + unsigned long mask = SCU_PM_POWEROFF << (cpu * 8); + + if ((__raw_readl(shmobile_scu_base + 8) & mask) == mask) + return 1; + + return 0; +} + +int shmobile_smp_scu_cpu_kill(unsigned int cpu) +{ + int k; + + /* this function is running on another CPU than the offline target, + * here we need wait for shutdown code in platform_cpu_die() to + * finish before asking SoC-specific code to power off the CPU core. + */ + for (k = 0; k < 1000; k++) { + if (shmobile_smp_scu_psr_core_disabled(cpu)) + return 1; + + mdelay(1); + } + + return 0; +} +#endif |