[PATCHv7 11/14] x86/mm: Make kernel_physical_mapping_init() support 5-level paging

Kirill A. Shutemov
2017-06-06T11:31:57Z

Populate additional page table level if CONFIG_X86_5LEVEL is enabled.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
arch/x86/mm/init_64.c | 69 ++++++++++++++++++++++++++++++++++++++++++++-------
1 file changed, 60 insertions(+), 9 deletions(-)

diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 7a9497ac468d..b863d14e452a 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -624,6 +624,57 @@ phys_pud_init(pud_t *pud_page, unsigned long paddr, unsigned long paddr_end,
return paddr_last;
}

+static unsigned long __meminit
+phys_p4d_init(p4d_t *p4d_page, unsigned long paddr, unsigned long paddr_end,
+ unsigned long page_size_mask)
+{
+ unsigned long paddr_next, paddr_last = paddr_end;
+ unsigned long vaddr = (unsigned long)__va(paddr);
+ int i = p4d_index(vaddr);
+
+ if (!IS_ENABLED(CONFIG_X86_5LEVEL))
+ return phys_pud_init((pud_t *) p4d_page, paddr, paddr_end, page_size_mask);
+
+ for (; i < PTRS_PER_P4D; i++, paddr = paddr_next) {
+ p4d_t *p4d;
+ pud_t *pud;
+
+ vaddr = (unsigned long)__va(paddr);
+ p4d = p4d_page + p4d_index(vaddr);
+ paddr_next = (paddr & P4D_MASK) + P4D_SIZE;
+
+ if (paddr >= paddr_end) {
+ if (!after_bootmem &&
+ !e820__mapped_any(paddr & P4D_MASK, paddr_next,
+ E820_TYPE_RAM) &&
+ !e820__mapped_any(paddr & P4D_MASK, paddr_next,
+ E820_TYPE_RESERVED_KERN))
+ set_p4d(p4d, __p4d(0));
+ continue;
+ }
+
+ if (!p4d_none(*p4d)) {
+ pud = pud_offset(p4d, 0);
+ paddr_last = phys_pud_init(pud, paddr,
+ paddr_end,
+ page_size_mask);
+ __flush_tlb_all();
+ continue;
+ }
+
+ pud = alloc_low_page();
+ paddr_last = phys_pud_init(pud, paddr, paddr_end,
+ page_size_mask);
+
+ spin_lock(&init_mm.page_table_lock);
+ p4d_populate(&init_mm, p4d, pud);
+ spin_unlock(&init_mm.page_table_lock);
+ }
+ __flush_tlb_all();
+
+ return paddr_last;
+}
+
/*
* Create page table mapping for the physical memory for specific physical
* addresses. The virtual and physical addresses have to be aligned on PMD level
@@ -645,26 +696,26 @@ kernel_physical_mapping_init(unsigned long paddr_start,
for (; vaddr < vaddr_end; vaddr = vaddr_next) {
pgd_t *pgd = pgd_offset_k(vaddr);
p4d_t *p4d;
- pud_t *pud;

vaddr_next = (vaddr & PGDIR_MASK) + PGDIR_SIZE;

- BUILD_BUG_ON(pgd_none(*pgd));
- p4d = p4d_offset(pgd, vaddr);
- if (p4d_val(*p4d)) {
- pud = (pud_t *)p4d_page_vaddr(*p4d);
- paddr_last = phys_pud_init(pud, __pa(vaddr),
+ if (pgd_val(*pgd)) {
+ p4d = (p4d_t *)pgd_page_vaddr(*pgd);
+ paddr_last = phys_p4d_init(p4d, __pa(vaddr),
__pa(vaddr_end),
page_size_mask);
continue;
}

- pud = alloc_low_page();
- paddr_last = phys_pud_init(pud, __pa(vaddr), __pa(vaddr_end),
+ p4d = alloc_low_page();
+ paddr_last = phys_p4d_init(p4d, __pa(vaddr), __pa(vaddr_end),
page_size_mask);

spin_lock(&init_mm.page_table_lock);
- p4d_populate(&init_mm, p4d, pud);
+ if (IS_ENABLED(CONFIG_X86_5LEVEL))
+ pgd_populate(&init_mm, pgd, p4d);
+ else
+ p4d_populate(&init_mm, p4d_offset(pgd, vaddr), (pud_t *) p4d);
spin_unlock(&init_mm.page_table_lock);
pgd_changed = true;
}
--
2.11.0