Commit 8121fbc4 authored by Mike Rapoport's avatar Mike Rapoport Committed by Helge Deller
Browse files

parisc: map_pages(): cleanup page table initialization 



The current code uses '#if PTRS_PER_PMD == 1' to distinguish 2 vs 3 levels,
setup, it casts pgd to pgd to cope with page table folding and converts
addresses of page table entries from physical to virtual and back for no
good reason.

Simplify the accesses to the page table entries using proper unfolding of
the upper layers and replacing '#if PTRS_PER_PMD' with explicit
'#if CONFIG_PGTABLE_LEVELS == 3'

Signed-off-by: default avatarMike Rapoport <rppt@linux.ibm.com>
Signed-off-by: default avatarHelge Deller <deller@gmx.de>
parent d5226fa6

arch/parisc/mm/init.c

+12 −38
Original line number Diff line number Diff line
@@ -351,7 +351,6 @@ static void __init map_pages(unsigned long start_vaddr, 
			     unsigned long start_paddr, unsigned long size,

			     pgprot_t pgprot, int force)

{

	pgd_t *pg_dir;

	pmd_t *pmd;

	pte_t *pg_table;

	unsigned long end_paddr;
@@ -372,62 +371,37 @@ static void __init map_pages(unsigned long start_vaddr, 


	end_paddr = start_paddr + size;



	pg_dir = pgd_offset_k(start_vaddr);



#if PTRS_PER_PMD == 1

	start_pmd = 0;

#else

	/* for 2-level configuration PTRS_PER_PMD is 0 so start_pmd will be 0 */

	start_pmd = ((start_vaddr >> PMD_SHIFT) & (PTRS_PER_PMD - 1));

#endif

	start_pte = ((start_vaddr >> PAGE_SHIFT) & (PTRS_PER_PTE - 1));



	address = start_paddr;

	vaddr = start_vaddr;

	while (address < end_paddr) {

#if PTRS_PER_PMD == 1

		pmd = (pmd_t *)__pa(pg_dir);

#else

		pmd = (pmd_t *)pgd_address(*pg_dir);

		pgd_t *pgd = pgd_offset_k(vaddr);

		p4d_t *p4d = p4d_offset(pgd, vaddr);

		pud_t *pud = pud_offset(p4d, vaddr);



		/*

		 * pmd is physical at this point

		 */



		if (!pmd) {

#if CONFIG_PGTABLE_LEVELS == 3

		if (pud_none(*pud)) {

			pmd = memblock_alloc(PAGE_SIZE << PMD_ORDER,

					     PAGE_SIZE << PMD_ORDER);

			if (!pmd)

				panic("pmd allocation failed.\n");

			pmd = (pmd_t *) __pa(pmd);

			pud_populate(NULL, pud, pmd);

		}



		pud_populate(NULL, (pud_t *)pg_dir, __va(pmd));

#endif

		pg_dir++;



		/* now change pmd to kernel virtual addresses */



		pmd = (pmd_t *)__va(pmd) + start_pmd;

		pmd = pmd_offset(pud, vaddr);

		for (tmp1 = start_pmd; tmp1 < PTRS_PER_PMD; tmp1++, pmd++) {



			/*

			 * pg_table is physical at this point

			 */



			pg_table = (pte_t *)pmd_address(*pmd);

			if (!pg_table) {

				pg_table = memblock_alloc(PAGE_SIZE,

							  PAGE_SIZE);

			if (pmd_none(*pmd)) {

				pg_table = memblock_alloc(PAGE_SIZE, PAGE_SIZE);

				if (!pg_table)

					panic("page table allocation failed\n");

				pg_table = (pte_t *) __pa(pg_table);

				pmd_populate_kernel(NULL, pmd, pg_table);

			}



			pmd_populate_kernel(NULL, pmd, __va(pg_table));



			/* now change pg_table to kernel virtual addresses */



			pg_table = (pte_t *) __va(pg_table) + start_pte;

			pg_table = pte_offset_kernel(pmd, vaddr);

			for (tmp2 = start_pte; tmp2 < PTRS_PER_PTE; tmp2++, pg_table++) {

				pte_t pte;

				pgprot_t prot;

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