1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Copyright 2005, Paul Mackerras, IBM Corporation.
4 * Copyright 2009, Benjamin Herrenschmidt, IBM Corporation.
5 * Copyright 2015-2016, Aneesh Kumar K.V, IBM Corporation.
8 #include <linux/sched.h>
9 #include <linux/memblock.h>
10 #include <asm/pgalloc.h>
14 #include <mm/mmu_decl.h>
16 #ifdef CONFIG_SPARSEMEM_VMEMMAP
18 * On Book3E CPUs, the vmemmap is currently mapped in the top half of
19 * the vmalloc space using normal page tables, though the size of
20 * pages encoded in the PTEs can be different
22 int __meminit vmemmap_create_mapping(unsigned long start,
23 unsigned long page_size,
26 /* Create a PTE encoding without page size */
27 unsigned long i, flags = _PAGE_PRESENT | _PAGE_ACCESSED |
30 /* PTEs only contain page size encodings up to 32M */
31 BUG_ON(mmu_psize_defs[mmu_vmemmap_psize].enc > 0xf);
33 /* Encode the size in the PTE */
34 flags |= mmu_psize_defs[mmu_vmemmap_psize].enc << 8;
36 /* For each PTE for that area, map things. Note that we don't
37 * increment phys because all PTEs are of the large size and
38 * thus must have the low bits clear
40 for (i = 0; i < page_size; i += PAGE_SIZE)
41 BUG_ON(map_kernel_page(start + i, phys, __pgprot(flags)));
46 #ifdef CONFIG_MEMORY_HOTPLUG
47 void vmemmap_remove_mapping(unsigned long start,
48 unsigned long page_size)
52 #endif /* CONFIG_SPARSEMEM_VMEMMAP */
54 static void __init *early_alloc_pgtable(unsigned long size)
58 ptr = memblock_alloc_try_nid(size, size, MEMBLOCK_LOW_LIMIT,
59 __pa(MAX_DMA_ADDRESS), NUMA_NO_NODE);
62 panic("%s: Failed to allocate %lu bytes align=0x%lx max_addr=%lx\n",
63 __func__, size, size, __pa(MAX_DMA_ADDRESS));
69 * map_kernel_page currently only called by __ioremap
70 * map_kernel_page adds an entry to the ioremap page table
71 * and adds an entry to the HPT, possibly bolting it
73 int __ref map_kernel_page(unsigned long ea, unsigned long pa, pgprot_t prot)
80 BUILD_BUG_ON(TASK_SIZE_USER64 > PGTABLE_RANGE);
81 if (slab_is_available()) {
82 pgdp = pgd_offset_k(ea);
83 pudp = pud_alloc(&init_mm, pgdp, ea);
86 pmdp = pmd_alloc(&init_mm, pudp, ea);
89 ptep = pte_alloc_kernel(pmdp, ea);
93 pgdp = pgd_offset_k(ea);
94 #ifndef __PAGETABLE_PUD_FOLDED
95 if (pgd_none(*pgdp)) {
96 pudp = early_alloc_pgtable(PUD_TABLE_SIZE);
97 pgd_populate(&init_mm, pgdp, pudp);
99 #endif /* !__PAGETABLE_PUD_FOLDED */
100 pudp = pud_offset(pgdp, ea);
101 if (pud_none(*pudp)) {
102 pmdp = early_alloc_pgtable(PMD_TABLE_SIZE);
103 pud_populate(&init_mm, pudp, pmdp);
105 pmdp = pmd_offset(pudp, ea);
106 if (!pmd_present(*pmdp)) {
107 ptep = early_alloc_pgtable(PAGE_SIZE);
108 pmd_populate_kernel(&init_mm, pmdp, ptep);
110 ptep = pte_offset_kernel(pmdp, ea);
112 set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT, prot));