xref: /openbmc/linux/arch/arc/include/asm/pgalloc.h (revision 8747ff70)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
4  *
5  * vineetg: June 2011
6  *  -"/proc/meminfo | grep PageTables" kept on increasing
7  *   Recently added pgtable dtor was not getting called.
8  *
9  * vineetg: May 2011
10  *  -Variable pg-sz means that Page Tables could be variable sized themselves
11  *    So calculate it based on addr traversal split [pgd-bits:pte-bits:xxx]
12  *  -Page Table size capped to max 1 to save memory - hence verified.
13  *  -Since these deal with constants, gcc compile-time optimizes them.
14  *
15  * vineetg: Nov 2010
16  *  -Added pgtable ctor/dtor used for pgtable mem accounting
17  *
18  * vineetg: April 2010
19  *  -Switched pgtable_t from being struct page * to unsigned long
20  *      =Needed so that Page Table allocator (pte_alloc_one) is not forced to
21  *       deal with struct page. That way in future we can make it allocate
22  *       multiple PG Tbls in one Page Frame
23  *      =sweet side effect is avoiding calls to ugly page_address( ) from the
24  *       pg-tlb allocator sub-sys (pte_alloc_one, ptr_free, pmd_populate)
25  *
26  *  Amit Bhor, Sameer Dhavale: Codito Technologies 2004
27  */
28 
29 #ifndef _ASM_ARC_PGALLOC_H
30 #define _ASM_ARC_PGALLOC_H
31 
32 #include <linux/mm.h>
33 #include <linux/log2.h>
34 #include <asm-generic/pgalloc.h>
35 
36 static inline void
pmd_populate_kernel(struct mm_struct * mm,pmd_t * pmd,pte_t * pte)37 pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd, pte_t *pte)
38 {
39 	/*
40 	 * The cast to long below is OK in 32-bit PAE40 regime with long long pte
41 	 * Despite "wider" pte, the pte table needs to be in non-PAE low memory
42 	 * as all higher levels can only hold long pointers.
43 	 *
44 	 * The cast itself is needed given simplistic definition of set_pmd()
45 	 */
46 	set_pmd(pmd, __pmd((unsigned long)pte));
47 }
48 
pmd_populate(struct mm_struct * mm,pmd_t * pmd,pgtable_t pte_page)49 static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd, pgtable_t pte_page)
50 {
51 	set_pmd(pmd, __pmd((unsigned long)page_address(pte_page)));
52 }
53 
pgd_alloc(struct mm_struct * mm)54 static inline pgd_t *pgd_alloc(struct mm_struct *mm)
55 {
56 	pgd_t *ret = (pgd_t *) __get_free_page(GFP_KERNEL);
57 
58 	if (ret) {
59 		int num, num2;
60 		num = USER_PTRS_PER_PGD + USER_KERNEL_GUTTER / PGDIR_SIZE;
61 		memzero(ret, num * sizeof(pgd_t));
62 
63 		num2 = VMALLOC_SIZE / PGDIR_SIZE;
64 		memcpy(ret + num, swapper_pg_dir + num, num2 * sizeof(pgd_t));
65 
66 		memzero(ret + num + num2,
67 			       (PTRS_PER_PGD - num - num2) * sizeof(pgd_t));
68 
69 	}
70 	return ret;
71 }
72 
73 #if CONFIG_PGTABLE_LEVELS > 3
74 
p4d_populate(struct mm_struct * mm,p4d_t * p4dp,pud_t * pudp)75 static inline void p4d_populate(struct mm_struct *mm, p4d_t *p4dp, pud_t *pudp)
76 {
77 	set_p4d(p4dp, __p4d((unsigned long)pudp));
78 }
79 
80 #define __pud_free_tlb(tlb, pmd, addr)  pud_free((tlb)->mm, pmd)
81 
82 #endif
83 
84 #if CONFIG_PGTABLE_LEVELS > 2
85 
pud_populate(struct mm_struct * mm,pud_t * pudp,pmd_t * pmdp)86 static inline void pud_populate(struct mm_struct *mm, pud_t *pudp, pmd_t *pmdp)
87 {
88 	set_pud(pudp, __pud((unsigned long)pmdp));
89 }
90 
91 #define __pmd_free_tlb(tlb, pmd, addr)  pmd_free((tlb)->mm, pmd)
92 
93 #endif
94 
95 #define __pte_free_tlb(tlb, pte, addr)  pte_free((tlb)->mm, pte)
96 
97 #endif /* _ASM_ARC_PGALLOC_H */
98