Commit 2a444fdc authored by Alexander Gordeev's avatar Alexander Gordeev Committed by Vasily Gorbik
Browse files

s390/mm: fix phys vs virt confusion in pgtable allocation routines 



The physical address of page tables is passed around and
used as virtual address in various locations.

Signed-off-by: default avatarAlexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: default avatarHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
parent 0f3bf303

arch/s390/include/asm/pgalloc.h

+1 −1
Original line number Diff line number Diff line
@@ -135,7 +135,7 @@ static inline void pmd_populate(struct mm_struct *mm, 
#define pmd_populate_kernel(mm, pmd, pte) pmd_populate(mm, pmd, pte)



#define pmd_pgtable(pmd) \

	(pgtable_t)(pmd_val(pmd) & -sizeof(pte_t)*PTRS_PER_PTE)

	((pgtable_t)__va(pmd_val(pmd) & -sizeof(pte_t)*PTRS_PER_PTE))



/*

 * page table entry allocation/free routines.

arch/s390/mm/pgalloc.c

+11 −11
Original line number Diff line number Diff line
@@ -58,7 +58,7 @@ unsigned long *crst_table_alloc(struct mm_struct *mm) 
	if (!page)

		return NULL;

	arch_set_page_dat(page, 2);

	return (unsigned long *) page_to_phys(page);

	return (unsigned long *) page_to_virt(page);

}



void crst_table_free(struct mm_struct *mm, unsigned long *table)
@@ -161,7 +161,7 @@ struct page *page_table_alloc_pgste(struct mm_struct *mm) 


	page = alloc_page(GFP_KERNEL);

	if (page) {

		table = (u64 *)page_to_phys(page);

		table = (u64 *)page_to_virt(page);

		memset64(table, _PAGE_INVALID, PTRS_PER_PTE);

		memset64(table + PTRS_PER_PTE, 0, PTRS_PER_PTE);

	}
@@ -194,7 +194,7 @@ unsigned long *page_table_alloc(struct mm_struct *mm) 
			mask = atomic_read(&page->_refcount) >> 24;

			mask = (mask | (mask >> 4)) & 3;

			if (mask != 3) {

				table = (unsigned long *) page_to_phys(page);

				table = (unsigned long *) page_to_virt(page);

				bit = mask & 1;		/* =1 -> second 2K */

				if (bit)

					table += PTRS_PER_PTE;
@@ -217,7 +217,7 @@ unsigned long *page_table_alloc(struct mm_struct *mm) 
	}

	arch_set_page_dat(page, 0);

	/* Initialize page table */

	table = (unsigned long *) page_to_phys(page);

	table = (unsigned long *) page_to_virt(page);

	if (mm_alloc_pgste(mm)) {

		/* Return 4K page table with PGSTEs */

		atomic_xor_bits(&page->_refcount, 3 << 24);
@@ -239,10 +239,10 @@ void page_table_free(struct mm_struct *mm, unsigned long *table) 
	struct page *page;

	unsigned int bit, mask;



	page = pfn_to_page(__pa(table) >> PAGE_SHIFT);

	page = virt_to_page(table);

	if (!mm_alloc_pgste(mm)) {

		/* Free 2K page table fragment of a 4K page */

		bit = (__pa(table) & ~PAGE_MASK)/(PTRS_PER_PTE*sizeof(pte_t));

		bit = ((unsigned long) table & ~PAGE_MASK)/(PTRS_PER_PTE*sizeof(pte_t));

		spin_lock_bh(&mm->context.lock);

		mask = atomic_xor_bits(&page->_refcount, 1U << (bit + 24));

		mask >>= 24;
@@ -269,14 +269,14 @@ void page_table_free_rcu(struct mmu_gather *tlb, unsigned long *table, 
	unsigned int bit, mask;



	mm = tlb->mm;

	page = pfn_to_page(__pa(table) >> PAGE_SHIFT);

	page = virt_to_page(table);

	if (mm_alloc_pgste(mm)) {

		gmap_unlink(mm, table, vmaddr);

		table = (unsigned long *) (__pa(table) | 3);

		table = (unsigned long *) ((unsigned long)table | 3);

		tlb_remove_table(tlb, table);

		return;

	}

	bit = (__pa(table) & ~PAGE_MASK) / (PTRS_PER_PTE*sizeof(pte_t));

	bit = ((unsigned long) table & ~PAGE_MASK) / (PTRS_PER_PTE*sizeof(pte_t));

	spin_lock_bh(&mm->context.lock);

	mask = atomic_xor_bits(&page->_refcount, 0x11U << (bit + 24));

	mask >>= 24;
@@ -285,7 +285,7 @@ void page_table_free_rcu(struct mmu_gather *tlb, unsigned long *table, 
	else

		list_del(&page->lru);

	spin_unlock_bh(&mm->context.lock);

	table = (unsigned long *) (__pa(table) | (1U << bit));

	table = (unsigned long *) ((unsigned long) table | (1U << bit));

	tlb_remove_table(tlb, table);

}
@@ -293,7 +293,7 @@ void __tlb_remove_table(void *_table) 
{

	unsigned int mask = (unsigned long) _table & 3;

	void *table = (void *)((unsigned long) _table ^ mask);

	struct page *page = pfn_to_page(__pa(table) >> PAGE_SHIFT);

	struct page *page = virt_to_page(table);



	switch (mask) {

	case 0:		/* pmd, pud, or p4d */