Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 5ea72a90 authored by Vineet Gupta's avatar Vineet Gupta
Browse files

ARC: [SMP] TLB flush 



- Add mm_cpumask setting (aggregating only, unlike some other arches)
  used to restrict the TLB flush cross-calling

- cross-calling versions of TLB flush routines (thanks to Noam)

Signed-off-by: default avatarNoam Camus <noamc@ezchip.com>
Signed-off-by: default avatarVineet Gupta <vgupta@synopsys.com>
parent 63eca94c

arch/arc/include/asm/mmu_context.h

+16 −1
Original line number Diff line number Diff line
@@ -80,7 +80,7 @@ static inline void get_new_mmu_context(struct mm_struct *mm) 
	/* move to new ASID and handle rollover */

	if (unlikely(!(++asid_cpu(cpu) & MM_CTXT_ASID_MASK))) {



		flush_tlb_all();

		local_flush_tlb_all();



		/*

		 * Above checke for rollover of 8 bit ASID in 32 bit container.
@@ -131,6 +131,21 @@ static inline void destroy_context(struct mm_struct *mm) 
static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,

			     struct task_struct *tsk)

{

	const int cpu = smp_processor_id();



	/*

	 * Note that the mm_cpumask is "aggregating" only, we don't clear it

	 * for the switched-out task, unlike some other arches.

	 * It is used to enlist cpus for sending TLB flush IPIs and not sending

	 * it to CPUs where a task once ran-on, could cause stale TLB entry

	 * re-use, specially for a multi-threaded task.

	 * e.g. T1 runs on C1, migrates to C3. T2 running on C2 munmaps.

	 *      For a non-aggregating mm_cpumask, IPI not sent C1, and if T1

	 *      were to re-migrate to C1, it could access the unmapped region

	 *      via any existing stale TLB entries.

	 */

	cpumask_set_cpu(cpu, mm_cpumask(next));



#ifndef CONFIG_SMP

	/* PGD cached in MMU reg to avoid 3 mem lookups: task->mm->pgd */

	write_aux_reg(ARC_REG_SCRATCH_DATA0, next->pgd);

arch/arc/include/asm/tlbflush.h

+9 −2
Original line number Diff line number Diff line
@@ -18,11 +18,18 @@ void local_flush_tlb_kernel_range(unsigned long start, unsigned long end); 
void local_flush_tlb_range(struct vm_area_struct *vma,

			   unsigned long start, unsigned long end);



/* XXX: Revisit for SMP */

#ifndef CONFIG_SMP

#define flush_tlb_range(vma, s, e)	local_flush_tlb_range(vma, s, e)

#define flush_tlb_page(vma, page)	local_flush_tlb_page(vma, page)

#define flush_tlb_kernel_range(s, e)	local_flush_tlb_kernel_range(s, e)

#define flush_tlb_all()			local_flush_tlb_all()

#define flush_tlb_mm(mm)		local_flush_tlb_mm(mm)



#else

extern void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,

							 unsigned long end);

extern void flush_tlb_page(struct vm_area_struct *vma, unsigned long page);

extern void flush_tlb_kernel_range(unsigned long start, unsigned long end);

extern void flush_tlb_all(void);

extern void flush_tlb_mm(struct mm_struct *mm);

#endif /* CONFIG_SMP */

#endif

arch/arc/kernel/smp.c

+1 −0
Original line number Diff line number Diff line
@@ -128,6 +128,7 @@ void start_kernel_secondary(void) 
	atomic_inc(&mm->mm_users);

	atomic_inc(&mm->mm_count);

	current->active_mm = mm;

	cpumask_set_cpu(cpu, mm_cpumask(mm));



	notify_cpu_starting(cpu);

	set_cpu_online(cpu, true);

arch/arc/mm/tlb.c

+73 −0
Original line number Diff line number Diff line
@@ -363,6 +363,79 @@ void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page) 
	local_irq_restore(flags);

}



#ifdef CONFIG_SMP



struct tlb_args {

	struct vm_area_struct *ta_vma;

	unsigned long ta_start;

	unsigned long ta_end;

};



static inline void ipi_flush_tlb_page(void *arg)

{

	struct tlb_args *ta = arg;



	local_flush_tlb_page(ta->ta_vma, ta->ta_start);

}



static inline void ipi_flush_tlb_range(void *arg)

{

	struct tlb_args *ta = arg;



	local_flush_tlb_range(ta->ta_vma, ta->ta_start, ta->ta_end);

}



static inline void ipi_flush_tlb_kernel_range(void *arg)

{

	struct tlb_args *ta = (struct tlb_args *)arg;



	local_flush_tlb_kernel_range(ta->ta_start, ta->ta_end);

}



void flush_tlb_all(void)

{

	on_each_cpu((smp_call_func_t)local_flush_tlb_all, NULL, 1);

}



void flush_tlb_mm(struct mm_struct *mm)

{

	on_each_cpu_mask(mm_cpumask(mm), (smp_call_func_t)local_flush_tlb_mm,

			 mm, 1);

}



void flush_tlb_page(struct vm_area_struct *vma, unsigned long uaddr)

{

	struct tlb_args ta = {

		.ta_vma = vma,

		.ta_start = uaddr

	};



	on_each_cpu_mask(mm_cpumask(vma->vm_mm), ipi_flush_tlb_page, &ta, 1);

}



void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,

		     unsigned long end)

{

	struct tlb_args ta = {

		.ta_vma = vma,

		.ta_start = start,

		.ta_end = end

	};



	on_each_cpu_mask(mm_cpumask(vma->vm_mm), ipi_flush_tlb_range, &ta, 1);

}



void flush_tlb_kernel_range(unsigned long start, unsigned long end)

{

	struct tlb_args ta = {

		.ta_start = start,

		.ta_end = end

	};



	on_each_cpu(ipi_flush_tlb_kernel_range, &ta, 1);

}

#endif



/*

 * Routine to create a TLB entry

 */