| Aneesh Kumar K.V | eee24b5 | 2016-04-29 23:25:44 +1000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2005, Paul Mackerras, IBM Corporation. |
| 3 | * Copyright 2009, Benjamin Herrenschmidt, IBM Corporation. |
| 4 | * Copyright 2015-2016, Aneesh Kumar K.V, IBM Corporation. |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU General Public License |
| 8 | * as published by the Free Software Foundation; either version |
| 9 | * 2 of the License, or (at your option) any later version. |
| 10 | */ |
| 11 | |
| 12 | #include <linux/sched.h> |
| 13 | #include <linux/memblock.h> |
| 14 | #include <asm/pgalloc.h> |
| 15 | #include <asm/tlb.h> |
| 16 | #include <asm/dma.h> |
| 17 | |
| 18 | #include "mmu_decl.h" |
| 19 | |
| 20 | #ifdef CONFIG_SPARSEMEM_VMEMMAP |
| 21 | /* |
| 22 | * On Book3E CPUs, the vmemmap is currently mapped in the top half of |
| 23 | * the vmalloc space using normal page tables, though the size of |
| 24 | * pages encoded in the PTEs can be different |
| 25 | */ |
| 26 | int __meminit vmemmap_create_mapping(unsigned long start, |
| 27 | unsigned long page_size, |
| 28 | unsigned long phys) |
| 29 | { |
| 30 | /* Create a PTE encoding without page size */ |
| 31 | unsigned long i, flags = _PAGE_PRESENT | _PAGE_ACCESSED | |
| 32 | _PAGE_KERNEL_RW; |
| 33 | |
| 34 | /* PTEs only contain page size encodings up to 32M */ |
| 35 | BUG_ON(mmu_psize_defs[mmu_vmemmap_psize].enc > 0xf); |
| 36 | |
| 37 | /* Encode the size in the PTE */ |
| 38 | flags |= mmu_psize_defs[mmu_vmemmap_psize].enc << 8; |
| 39 | |
| 40 | /* For each PTE for that area, map things. Note that we don't |
| 41 | * increment phys because all PTEs are of the large size and |
| 42 | * thus must have the low bits clear |
| 43 | */ |
| 44 | for (i = 0; i < page_size; i += PAGE_SIZE) |
| 45 | BUG_ON(map_kernel_page(start + i, phys, flags)); |
| 46 | |
| 47 | return 0; |
| 48 | } |
| 49 | |
| 50 | #ifdef CONFIG_MEMORY_HOTPLUG |
| 51 | void vmemmap_remove_mapping(unsigned long start, |
| 52 | unsigned long page_size) |
| 53 | { |
| 54 | } |
| 55 | #endif |
| 56 | #endif /* CONFIG_SPARSEMEM_VMEMMAP */ |
| 57 | |
| 58 | static __ref void *early_alloc_pgtable(unsigned long size) |
| 59 | { |
| 60 | void *pt; |
| 61 | |
| 62 | pt = __va(memblock_alloc_base(size, size, __pa(MAX_DMA_ADDRESS))); |
| 63 | memset(pt, 0, size); |
| 64 | |
| 65 | return pt; |
| 66 | } |
| 67 | |
| 68 | /* |
| 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 |
| 72 | */ |
| 73 | int map_kernel_page(unsigned long ea, unsigned long pa, unsigned long flags) |
| 74 | { |
| 75 | pgd_t *pgdp; |
| 76 | pud_t *pudp; |
| 77 | pmd_t *pmdp; |
| 78 | pte_t *ptep; |
| 79 | |
| 80 | if (slab_is_available()) { |
| 81 | pgdp = pgd_offset_k(ea); |
| 82 | pudp = pud_alloc(&init_mm, pgdp, ea); |
| 83 | if (!pudp) |
| 84 | return -ENOMEM; |
| 85 | pmdp = pmd_alloc(&init_mm, pudp, ea); |
| 86 | if (!pmdp) |
| 87 | return -ENOMEM; |
| 88 | ptep = pte_alloc_kernel(pmdp, ea); |
| 89 | if (!ptep) |
| 90 | return -ENOMEM; |
| 91 | set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT, |
| 92 | __pgprot(flags))); |
| 93 | } else { |
| 94 | pgdp = pgd_offset_k(ea); |
| 95 | #ifndef __PAGETABLE_PUD_FOLDED |
| 96 | if (pgd_none(*pgdp)) { |
| 97 | pudp = early_alloc_pgtable(PUD_TABLE_SIZE); |
| 98 | BUG_ON(pudp == NULL); |
| 99 | pgd_populate(&init_mm, pgdp, pudp); |
| 100 | } |
| 101 | #endif /* !__PAGETABLE_PUD_FOLDED */ |
| 102 | pudp = pud_offset(pgdp, ea); |
| 103 | if (pud_none(*pudp)) { |
| 104 | pmdp = early_alloc_pgtable(PMD_TABLE_SIZE); |
| 105 | BUG_ON(pmdp == NULL); |
| 106 | pud_populate(&init_mm, pudp, pmdp); |
| 107 | } |
| 108 | pmdp = pmd_offset(pudp, ea); |
| 109 | if (!pmd_present(*pmdp)) { |
| 110 | ptep = early_alloc_pgtable(PAGE_SIZE); |
| 111 | BUG_ON(ptep == NULL); |
| 112 | pmd_populate_kernel(&init_mm, pmdp, ptep); |
| 113 | } |
| 114 | ptep = pte_offset_kernel(pmdp, ea); |
| 115 | set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT, |
| 116 | __pgprot(flags))); |
| 117 | } |
| 118 | |
| 119 | smp_wmb(); |
| 120 | return 0; |
| 121 | } |