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-rw-r--r--arch/arm/mm/context.c35
1 files changed, 35 insertions, 0 deletions
diff --git a/arch/arm/mm/context.c b/arch/arm/mm/context.c
index 806cc4f63516..119bc52ab93e 100644
--- a/arch/arm/mm/context.c
+++ b/arch/arm/mm/context.c
@@ -14,6 +14,7 @@
14#include <linux/percpu.h> 14#include <linux/percpu.h>
15 15
16#include <asm/mmu_context.h> 16#include <asm/mmu_context.h>
17#include <asm/thread_notify.h>
17#include <asm/tlbflush.h> 18#include <asm/tlbflush.h>
18 19
19static DEFINE_RAW_SPINLOCK(cpu_asid_lock); 20static DEFINE_RAW_SPINLOCK(cpu_asid_lock);
@@ -48,6 +49,40 @@ void cpu_set_reserved_ttbr0(void)
48} 49}
49#endif 50#endif
50 51
52#ifdef CONFIG_PID_IN_CONTEXTIDR
53static int contextidr_notifier(struct notifier_block *unused, unsigned long cmd,
54 void *t)
55{
56 u32 contextidr;
57 pid_t pid;
58 struct thread_info *thread = t;
59
60 if (cmd != THREAD_NOTIFY_SWITCH)
61 return NOTIFY_DONE;
62
63 pid = task_pid_nr(thread->task) << ASID_BITS;
64 asm volatile(
65 " mrc p15, 0, %0, c13, c0, 1\n"
66 " bfi %1, %0, #0, %2\n"
67 " mcr p15, 0, %1, c13, c0, 1\n"
68 : "=r" (contextidr), "+r" (pid)
69 : "I" (ASID_BITS));
70 isb();
71
72 return NOTIFY_OK;
73}
74
75static struct notifier_block contextidr_notifier_block = {
76 .notifier_call = contextidr_notifier,
77};
78
79static int __init contextidr_notifier_init(void)
80{
81 return thread_register_notifier(&contextidr_notifier_block);
82}
83arch_initcall(contextidr_notifier_init);
84#endif
85
51/* 86/*
52 * We fork()ed a process, and we need a new context for the child 87 * We fork()ed a process, and we need a new context for the child
53 * to run in. 88 * to run in.