1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * OpenRISC Linux
4  *
5  * Linux architectural port borrowing liberally from similar works of
6  * others.  All original copyrights apply as per the original source
7  * declaration.
8  *
9  * OpenRISC implementation:
10  * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
11  * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
12  * et al.
13  */
14 
15 #ifndef __ASM_OPENRISC_PGALLOC_H
16 #define __ASM_OPENRISC_PGALLOC_H
17 
18 #include <asm/page.h>
19 #include <linux/threads.h>
20 #include <linux/mm.h>
21 #include <linux/memblock.h>
22 
23 #define __HAVE_ARCH_PTE_ALLOC_ONE_KERNEL
24 #include <asm-generic/pgalloc.h>
25 
26 extern int mem_init_done;
27 
28 #define pmd_populate_kernel(mm, pmd, pte) \
29 	set_pmd(pmd, __pmd(_KERNPG_TABLE + __pa(pte)))
30 
31 static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
32 				struct page *pte)
33 {
34 	set_pmd(pmd, __pmd(_KERNPG_TABLE +
35 		     ((unsigned long)page_to_pfn(pte) <<
36 		     (unsigned long) PAGE_SHIFT)));
37 }
38 
39 /*
40  * Allocate and free page tables.
41  */
42 static inline pgd_t *pgd_alloc(struct mm_struct *mm)
43 {
44 	pgd_t *ret = (pgd_t *)__get_free_page(GFP_KERNEL);
45 
46 	if (ret) {
47 		memset(ret, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
48 		memcpy(ret + USER_PTRS_PER_PGD,
49 		       swapper_pg_dir + USER_PTRS_PER_PGD,
50 		       (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
51 
52 	}
53 	return ret;
54 }
55 
56 #if 0
57 /* FIXME: This seems to be the preferred style, but we are using
58  * current_pgd (from mm->pgd) to load kernel pages so we need it
59  * initialized.  This needs to be looked into.
60  */
61 extern inline pgd_t *pgd_alloc(struct mm_struct *mm)
62 {
63 	return (pgd_t *)get_zeroed_page(GFP_KERNEL);
64 }
65 #endif
66 
67 extern pte_t *pte_alloc_one_kernel(struct mm_struct *mm);
68 
69 #define __pte_free_tlb(tlb, pte, addr)				\
70 do {								\
71 	pagetable_pte_dtor(page_ptdesc(pte));			\
72 	tlb_remove_page_ptdesc((tlb), (page_ptdesc(pte)));	\
73 } while (0)
74 
75 #endif
76