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-rw-r--r--arch/arm/mm/context.c36
1 files changed, 36 insertions, 0 deletions
diff --git a/arch/arm/mm/context.c b/arch/arm/mm/context.c
index 806cc4f..4e07eec 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 +49,41 @@ 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"
+ " and %0, %0, %2\n"
+ " orr %0, %0, %1\n"
+ " mcr p15, 0, %0, c13, c0, 1\n"
+ : "=r" (contextidr), "+r" (pid)
+ : "I" (~ASID_MASK));
+ 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.