| xj | b04a402 | 2021-11-25 15:01:52 +0800 | [diff] [blame] | 1 | /* |
| 2 | * PGD allocation/freeing |
| 3 | * |
| 4 | * Copyright (C) 2012 ARM Ltd. |
| 5 | * Author: Catalin Marinas <catalin.marinas@arm.com> |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License version 2 as |
| 9 | * published by the Free Software Foundation. |
| 10 | * |
| 11 | * This program is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | * GNU General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU General Public License |
| 17 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 18 | */ |
| 19 | |
| 20 | #include <linux/mm.h> |
| 21 | #include <linux/gfp.h> |
| 22 | #include <linux/highmem.h> |
| 23 | #include <linux/slab.h> |
| 24 | |
| 25 | #include <asm/pgalloc.h> |
| 26 | #include <asm/page.h> |
| 27 | #include <asm/tlbflush.h> |
| 28 | |
| 29 | static struct kmem_cache *pgd_cache __ro_after_init; |
| 30 | |
| 31 | pgd_t *pgd_alloc(struct mm_struct *mm) |
| 32 | { |
| 33 | if (PGD_SIZE == PAGE_SIZE) |
| 34 | return (pgd_t *)__get_free_page(PGALLOC_GFP); |
| 35 | else |
| 36 | return kmem_cache_alloc(pgd_cache, PGALLOC_GFP); |
| 37 | } |
| 38 | |
| 39 | void pgd_free(struct mm_struct *mm, pgd_t *pgd) |
| 40 | { |
| 41 | if (PGD_SIZE == PAGE_SIZE) |
| 42 | free_page((unsigned long)pgd); |
| 43 | else |
| 44 | kmem_cache_free(pgd_cache, pgd); |
| 45 | } |
| 46 | |
| 47 | void __init pgd_cache_init(void) |
| 48 | { |
| 49 | if (PGD_SIZE == PAGE_SIZE) |
| 50 | return; |
| 51 | |
| 52 | #ifdef CONFIG_ARM64_PA_BITS_52 |
| 53 | /* |
| 54 | * With 52-bit physical addresses, the architecture requires the |
| 55 | * top-level table to be aligned to at least 64 bytes. |
| 56 | */ |
| 57 | BUILD_BUG_ON(PGD_SIZE < 64); |
| 58 | #endif |
| 59 | |
| 60 | /* |
| 61 | * Naturally aligned pgds required by the architecture. |
| 62 | */ |
| 63 | pgd_cache = kmem_cache_create("pgd_cache", PGD_SIZE, PGD_SIZE, |
| 64 | SLAB_PANIC, NULL); |
| 65 | } |