diff options
Diffstat (limited to 'arch/arm/mm/context.c')
| -rw-r--r-- | arch/arm/mm/context.c | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/arch/arm/mm/context.c b/arch/arm/mm/context.c index 806cc4f6351..119bc52ab93 100644 --- a/arch/arm/mm/context.c +++ b/arch/arm/mm/context.c @@ -14,6 +14,7 @@ #include <linux/percpu.h> #include <asm/mmu_context.h> +#include <asm/thread_notify.h> #include <asm/tlbflush.h> static DEFINE_RAW_SPINLOCK(cpu_asid_lock); @@ -48,6 +49,40 @@ void cpu_set_reserved_ttbr0(void) } #endif +#ifdef CONFIG_PID_IN_CONTEXTIDR +static int contextidr_notifier(struct notifier_block *unused, unsigned long cmd, + void *t) +{ + u32 contextidr; + pid_t pid; + struct thread_info *thread = t; + + if (cmd != THREAD_NOTIFY_SWITCH) + return NOTIFY_DONE; + + pid = task_pid_nr(thread->task) << ASID_BITS; + asm volatile( + " mrc p15, 0, %0, c13, c0, 1\n" + " bfi %1, %0, #0, %2\n" + " mcr p15, 0, %1, c13, c0, 1\n" + : "=r" (contextidr), "+r" (pid) + : "I" (ASID_BITS)); + isb(); + + return NOTIFY_OK; +} + +static struct notifier_block contextidr_notifier_block = { + .notifier_call = contextidr_notifier, +}; + +static int __init contextidr_notifier_init(void) +{ + return thread_register_notifier(&contextidr_notifier_block); +} +arch_initcall(contextidr_notifier_init); +#endif + /* * We fork()ed a process, and we need a new context for the child * to run in. |