diff options
Diffstat (limited to 'arch/powerpc/mm/pgtable-book3e.c')
-rw-r--r-- | arch/powerpc/mm/pgtable-book3e.c | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/arch/powerpc/mm/pgtable-book3e.c b/arch/powerpc/mm/pgtable-book3e.c new file mode 100644 index 000000000..a2298930f --- /dev/null +++ b/arch/powerpc/mm/pgtable-book3e.c @@ -0,0 +1,122 @@ +/* + * Copyright 2005, Paul Mackerras, IBM Corporation. + * Copyright 2009, Benjamin Herrenschmidt, IBM Corporation. + * Copyright 2015-2016, Aneesh Kumar K.V, IBM Corporation. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include <linux/sched.h> +#include <linux/memblock.h> +#include <asm/pgalloc.h> +#include <asm/tlb.h> +#include <asm/dma.h> + +#include "mmu_decl.h" + +#ifdef CONFIG_SPARSEMEM_VMEMMAP +/* + * On Book3E CPUs, the vmemmap is currently mapped in the top half of + * the vmalloc space using normal page tables, though the size of + * pages encoded in the PTEs can be different + */ +int __meminit vmemmap_create_mapping(unsigned long start, + unsigned long page_size, + unsigned long phys) +{ + /* Create a PTE encoding without page size */ + unsigned long i, flags = _PAGE_PRESENT | _PAGE_ACCESSED | + _PAGE_KERNEL_RW; + + /* PTEs only contain page size encodings up to 32M */ + BUG_ON(mmu_psize_defs[mmu_vmemmap_psize].enc > 0xf); + + /* Encode the size in the PTE */ + flags |= mmu_psize_defs[mmu_vmemmap_psize].enc << 8; + + /* For each PTE for that area, map things. Note that we don't + * increment phys because all PTEs are of the large size and + * thus must have the low bits clear + */ + for (i = 0; i < page_size; i += PAGE_SIZE) + BUG_ON(map_kernel_page(start + i, phys, flags)); + + return 0; +} + +#ifdef CONFIG_MEMORY_HOTPLUG +void vmemmap_remove_mapping(unsigned long start, + unsigned long page_size) +{ +} +#endif +#endif /* CONFIG_SPARSEMEM_VMEMMAP */ + +static __ref void *early_alloc_pgtable(unsigned long size) +{ + void *pt; + + pt = __va(memblock_alloc_base(size, size, __pa(MAX_DMA_ADDRESS))); + memset(pt, 0, size); + + return pt; +} + +/* + * map_kernel_page currently only called by __ioremap + * map_kernel_page adds an entry to the ioremap page table + * and adds an entry to the HPT, possibly bolting it + */ +int map_kernel_page(unsigned long ea, unsigned long pa, unsigned long flags) +{ + pgd_t *pgdp; + pud_t *pudp; + pmd_t *pmdp; + pte_t *ptep; + + BUILD_BUG_ON(TASK_SIZE_USER64 > PGTABLE_RANGE); + if (slab_is_available()) { + pgdp = pgd_offset_k(ea); + pudp = pud_alloc(&init_mm, pgdp, ea); + if (!pudp) + return -ENOMEM; + pmdp = pmd_alloc(&init_mm, pudp, ea); + if (!pmdp) + return -ENOMEM; + ptep = pte_alloc_kernel(pmdp, ea); + if (!ptep) + return -ENOMEM; + set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT, + __pgprot(flags))); + } else { + pgdp = pgd_offset_k(ea); +#ifndef __PAGETABLE_PUD_FOLDED + if (pgd_none(*pgdp)) { + pudp = early_alloc_pgtable(PUD_TABLE_SIZE); + BUG_ON(pudp == NULL); + pgd_populate(&init_mm, pgdp, pudp); + } +#endif /* !__PAGETABLE_PUD_FOLDED */ + pudp = pud_offset(pgdp, ea); + if (pud_none(*pudp)) { + pmdp = early_alloc_pgtable(PMD_TABLE_SIZE); + BUG_ON(pmdp == NULL); + pud_populate(&init_mm, pudp, pmdp); + } + pmdp = pmd_offset(pudp, ea); + if (!pmd_present(*pmdp)) { + ptep = early_alloc_pgtable(PAGE_SIZE); + BUG_ON(ptep == NULL); + pmd_populate_kernel(&init_mm, pmdp, ptep); + } + ptep = pte_offset_kernel(pmdp, ea); + set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT, + __pgprot(flags))); + } + + smp_wmb(); + return 0; +} |