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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: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Helge Deller <deller@gmx.de>
This commit is contained in:
Mike Rapoport 2020-01-12 13:36:15 +02:00 committed by Helge Deller
parent d5226fa6db
commit 8121fbc4eb
1 changed files with 12 additions and 38 deletions
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50
arch/parisc/mm/init.c
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@ -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;