diff options
Diffstat (limited to 'arch/nios2/mm')
| -rw-r--r-- | arch/nios2/mm/pgtable.c | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/arch/nios2/mm/pgtable.c b/arch/nios2/mm/pgtable.c new file mode 100644 index 000000000000..61e24a25f71a --- /dev/null +++ b/arch/nios2/mm/pgtable.c @@ -0,0 +1,74 @@ +/* + * Copyright (C) 2009 Wind River Systems Inc + * Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ + +#include <linux/mm.h> +#include <linux/sched.h> + +#include <asm/pgtable.h> +#include <asm/cpuinfo.h> + +/* pteaddr: + * ptbase | vpn* | zero + * 31-22 | 21-2 | 1-0 + * + * *vpn is preserved on double fault + * + * tlbacc: + * IG |*flags| pfn + * 31-25|24-20 | 19-0 + * + * *crwxg + * + * tlbmisc: + * resv |way |rd | we|pid |dbl|bad|perm|d + * 31-24 |23-20 |19 | 20|17-4|3 |2 |1 |0 + * + */ + +/* + * Initialize a new pgd / pmd table with invalid pointers. + */ +static void pgd_init(pgd_t *pgd) +{ + unsigned long *p = (unsigned long *) pgd; + int i; + + for (i = 0; i < USER_PTRS_PER_PGD; i += 8) { + p[i + 0] = (unsigned long) invalid_pte_table; + p[i + 1] = (unsigned long) invalid_pte_table; + p[i + 2] = (unsigned long) invalid_pte_table; + p[i + 3] = (unsigned long) invalid_pte_table; + p[i + 4] = (unsigned long) invalid_pte_table; + p[i + 5] = (unsigned long) invalid_pte_table; + p[i + 6] = (unsigned long) invalid_pte_table; + p[i + 7] = (unsigned long) invalid_pte_table; + } +} + +pgd_t *pgd_alloc(struct mm_struct *mm) +{ + pgd_t *ret, *init; + + ret = (pgd_t *) __get_free_pages(GFP_KERNEL, PGD_ORDER); + if (ret) { + init = pgd_offset(&init_mm, 0UL); + pgd_init(ret); + memcpy(ret + USER_PTRS_PER_PGD, init + USER_PTRS_PER_PGD, + (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t)); + } + + return ret; +} + +void __init pagetable_init(void) +{ + /* Initialize the entire pgd. */ + pgd_init(swapper_pg_dir); + pgd_init(swapper_pg_dir + USER_PTRS_PER_PGD); +} |