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Commit bcd896ba authored by David S. Miller's avatar David S. Miller
Browse files

sparc64: Handle hugepage TSB being NULL. 



Accomodate the possibility that the TSB might be NULL at
the point that update_mmu_cache() is invoked.  This is
necessary because we will sometimes need to defer the TSB
allocation to the first fault that happens in the 'mm'.

Seperate out the hugepage PTE test into a seperate function
so that the logic is clearer.

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a55ee1ff

arch/sparc/mm/init_64.c

+22 −16
Original line number Diff line number Diff line
@@ -314,16 +314,31 @@ static void __update_mmu_tsb_insert(struct mm_struct *mm, unsigned long tsb_inde 
	struct tsb *tsb = mm->context.tsb_block[tsb_index].tsb;

	unsigned long tag;



	if (unlikely(!tsb))

		return;



	tsb += ((address >> tsb_hash_shift) &

		(mm->context.tsb_block[tsb_index].tsb_nentries - 1UL));

	tag = (address >> 22UL);

	tsb_insert(tsb, tag, tte);

}



#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)

static inline bool is_hugetlb_pte(pte_t pte)

{

	if ((tlb_type == hypervisor &&

	     (pte_val(pte) & _PAGE_SZALL_4V) == _PAGE_SZHUGE_4V) ||

	    (tlb_type != hypervisor &&

	     (pte_val(pte) & _PAGE_SZALL_4U) == _PAGE_SZHUGE_4U))

		return true;

	return false;

}

#endif



void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *ptep)

{

	unsigned long tsb_index, tsb_hash_shift, flags;

	struct mm_struct *mm;

	unsigned long flags;

	pte_t pte = *ptep;



	if (tlb_type != hypervisor) {
@@ -335,24 +350,15 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t * 


	mm = vma->vm_mm;



	tsb_index = MM_TSB_BASE;

	tsb_hash_shift = PAGE_SHIFT;



	spin_lock_irqsave(&mm->context.lock, flags);



#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)

	if (mm->context.tsb_block[MM_TSB_HUGE].tsb != NULL) {

		if ((tlb_type == hypervisor &&

		     (pte_val(pte) & _PAGE_SZALL_4V) == _PAGE_SZHUGE_4V) ||

		    (tlb_type != hypervisor &&

		     (pte_val(pte) & _PAGE_SZALL_4U) == _PAGE_SZHUGE_4U)) {

			tsb_index = MM_TSB_HUGE;

			tsb_hash_shift = HPAGE_SHIFT;

		}

	}

	if (mm->context.huge_pte_count && is_hugetlb_pte(pte))

		__update_mmu_tsb_insert(mm, MM_TSB_HUGE, HPAGE_SHIFT,

					address, pte_val(pte));

	else

#endif



	__update_mmu_tsb_insert(mm, tsb_index, tsb_hash_shift,

		__update_mmu_tsb_insert(mm, MM_TSB_BASE, PAGE_SHIFT,

					address, pte_val(pte));



	spin_unlock_irqrestore(&mm->context.lock, flags);