From 1aea9b3f921003f0880f0676ae85d87c9f1cb4a2 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Mon, 24 Apr 2017 18:19:10 +0200 Subject: s390/mm: implement 5 level pages tables Add the logic to upgrade the page table for a 64-bit process to five levels. This increases the TASK_SIZE from 8PB to 16EB-4K. Signed-off-by: Martin Schwidefsky --- arch/s390/mm/vmem.c | 44 +++++++++++++++++++++++++++++++++++++++----- 1 file changed, 39 insertions(+), 5 deletions(-) (limited to 'arch/s390/mm/vmem.c') diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c index c33c94b..d839896 100644 --- a/arch/s390/mm/vmem.c +++ b/arch/s390/mm/vmem.c @@ -38,6 +38,17 @@ static void __ref *vmem_alloc_pages(unsigned int order) return (void *) memblock_alloc(size, size); } +static inline p4d_t *vmem_p4d_alloc(void) +{ + p4d_t *p4d = NULL; + + p4d = vmem_alloc_pages(2); + if (!p4d) + return NULL; + clear_table((unsigned long *) p4d, _REGION2_ENTRY_EMPTY, PAGE_SIZE * 4); + return p4d; +} + static inline pud_t *vmem_pud_alloc(void) { pud_t *pud = NULL; @@ -85,6 +96,7 @@ static int vmem_add_mem(unsigned long start, unsigned long size) unsigned long end = start + size; unsigned long address = start; pgd_t *pg_dir; + p4d_t *p4_dir; pud_t *pu_dir; pmd_t *pm_dir; pte_t *pt_dir; @@ -102,12 +114,19 @@ static int vmem_add_mem(unsigned long start, unsigned long size) while (address < end) { pg_dir = pgd_offset_k(address); if (pgd_none(*pg_dir)) { + p4_dir = vmem_p4d_alloc(); + if (!p4_dir) + goto out; + pgd_populate(&init_mm, pg_dir, p4_dir); + } + p4_dir = p4d_offset(pg_dir, address); + if (p4d_none(*p4_dir)) { pu_dir = vmem_pud_alloc(); if (!pu_dir) goto out; - pgd_populate(&init_mm, pg_dir, pu_dir); + p4d_populate(&init_mm, p4_dir, pu_dir); } - pu_dir = pud_offset(pg_dir, address); + pu_dir = pud_offset(p4_dir, address); if (MACHINE_HAS_EDAT2 && pud_none(*pu_dir) && address && !(address & ~PUD_MASK) && (address + PUD_SIZE <= end) && !debug_pagealloc_enabled()) { @@ -161,6 +180,7 @@ static void vmem_remove_range(unsigned long start, unsigned long size) unsigned long end = start + size; unsigned long address = start; pgd_t *pg_dir; + p4d_t *p4_dir; pud_t *pu_dir; pmd_t *pm_dir; pte_t *pt_dir; @@ -172,7 +192,12 @@ static void vmem_remove_range(unsigned long start, unsigned long size) address += PGDIR_SIZE; continue; } - pu_dir = pud_offset(pg_dir, address); + p4_dir = p4d_offset(pg_dir, address); + if (p4d_none(*p4_dir)) { + address += P4D_SIZE; + continue; + } + pu_dir = pud_offset(p4_dir, address); if (pud_none(*pu_dir)) { address += PUD_SIZE; continue; @@ -213,6 +238,7 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node) unsigned long pgt_prot, sgt_prot; unsigned long address = start; pgd_t *pg_dir; + p4d_t *p4_dir; pud_t *pu_dir; pmd_t *pm_dir; pte_t *pt_dir; @@ -227,13 +253,21 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node) for (address = start; address < end;) { pg_dir = pgd_offset_k(address); if (pgd_none(*pg_dir)) { + p4_dir = vmem_p4d_alloc(); + if (!p4_dir) + goto out; + pgd_populate(&init_mm, pg_dir, p4_dir); + } + + p4_dir = p4d_offset(pg_dir, address); + if (p4d_none(*p4_dir)) { pu_dir = vmem_pud_alloc(); if (!pu_dir) goto out; - pgd_populate(&init_mm, pg_dir, pu_dir); + p4d_populate(&init_mm, p4_dir, pu_dir); } - pu_dir = pud_offset(pg_dir, address); + pu_dir = pud_offset(p4_dir, address); if (pud_none(*pu_dir)) { pm_dir = vmem_pmd_alloc(); if (!pm_dir) -- cgit v1.1