#include <asm/mmu_context.h>
#include <asm/tlbflush.h>
-unsigned int cpu_last_asid = { 1 << ASID_BITS };
+static DEFINE_SPINLOCK(cpu_asid_lock);
+unsigned int cpu_last_asid = ASID_FIRST_VERSION;
/*
* We fork()ed a process, and we need a new context for the child
* to run in. We reserve version 0 for initial tasks so we will
- * always allocate an ASID.
+ * always allocate an ASID. The ASID 0 is reserved for the TTBR
+ * register changing sequence.
*/
void __init_new_context(struct task_struct *tsk, struct mm_struct *mm)
{
{
unsigned int asid;
+ spin_lock(&cpu_asid_lock);
asid = ++cpu_last_asid;
if (asid == 0)
- asid = cpu_last_asid = 1 << ASID_BITS;
+ asid = cpu_last_asid = ASID_FIRST_VERSION;
/*
* If we've used up all our ASIDs, we need
* to start a new version and flush the TLB.
*/
- if ((asid & ~ASID_MASK) == 0)
+ if (unlikely((asid & ~ASID_MASK) == 0)) {
+ asid = ++cpu_last_asid;
+ /* set the reserved ASID before flushing the TLB */
+ asm("mcr p15, 0, %0, c13, c0, 1 @ set reserved context ID\n"
+ :
+ : "r" (0));
+ isb();
flush_tlb_all();
+ if (icache_is_vivt_asid_tagged()) {
+ asm("mcr p15, 0, %0, c7, c5, 0 @ invalidate I-cache\n"
+ "mcr p15, 0, %0, c7, c5, 6 @ flush BTAC/BTB\n"
+ :
+ : "r" (0));
+ dsb();
+ }
+ }
+ spin_unlock(&cpu_asid_lock);
+ mm->cpu_vm_mask = cpumask_of_cpu(smp_processor_id());
mm->context.id = asid;
}