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 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 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 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 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 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