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a9b3c355c2
We already have a generic implementation of alloc/free up to P4D level, as
well as pgd_free(). Let's finish the work and add a generic PGD-level
alloc helper as well.
Unlike at lower levels, almost all architectures need some specific magic
at PGD level (typically initialising PGD entries), so introducing a
generic pgd_alloc() isn't worth it. Instead we introduce two new helpers,
__pgd_alloc() and __pgd_free(), and make use of them in the arch-specific
pgd_alloc() and pgd_free() wherever possible. To accommodate as many arch
as possible, __pgd_alloc() takes a page allocation order.
Because pagetable_alloc() allocates zeroed pages, explicit zeroing in
pgd_alloc() becomes redundant and we can get rid of it. Some trivial
implementations of pgd_free() also become unnecessary once __pgd_alloc()
is used; remove them.
Another small improvement is consistent accounting of PGD pages by using
GFP_PGTABLE_{USER,KERNEL} as appropriate.
Not all PGD allocations can be handled by the generic helpers. In
particular, multiple architectures allocate PGDs from a kmem_cache, and
those PGDs may not be page-sized.
Link: https://lkml.kernel.org/r/20250103184415.2744423-6-kevin.brodsky@arm.com
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
93 lines
2.7 KiB
C
93 lines
2.7 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
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*
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* vineetg: June 2011
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* -"/proc/meminfo | grep PageTables" kept on increasing
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* Recently added pgtable dtor was not getting called.
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*
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* vineetg: May 2011
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* -Variable pg-sz means that Page Tables could be variable sized themselves
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* So calculate it based on addr traversal split [pgd-bits:pte-bits:xxx]
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* -Page Table size capped to max 1 to save memory - hence verified.
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* -Since these deal with constants, gcc compile-time optimizes them.
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*
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* vineetg: Nov 2010
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* -Added pgtable ctor/dtor used for pgtable mem accounting
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*
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* vineetg: April 2010
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* -Switched pgtable_t from being struct page * to unsigned long
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* =Needed so that Page Table allocator (pte_alloc_one) is not forced to
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* deal with struct page. That way in future we can make it allocate
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* multiple PG Tbls in one Page Frame
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* =sweet side effect is avoiding calls to ugly page_address( ) from the
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* pg-tlb allocator sub-sys (pte_alloc_one, ptr_free, pmd_populate)
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*
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* Amit Bhor, Sameer Dhavale: Codito Technologies 2004
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*/
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#ifndef _ASM_ARC_PGALLOC_H
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#define _ASM_ARC_PGALLOC_H
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#include <linux/mm.h>
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#include <linux/log2.h>
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#include <asm-generic/pgalloc.h>
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static inline void
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pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd, pte_t *pte)
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{
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/*
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* The cast to long below is OK in 32-bit PAE40 regime with long long pte
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* Despite "wider" pte, the pte table needs to be in non-PAE low memory
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* as all higher levels can only hold long pointers.
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*
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* The cast itself is needed given simplistic definition of set_pmd()
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*/
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set_pmd(pmd, __pmd((unsigned long)pte));
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}
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static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd, pgtable_t pte_page)
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{
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set_pmd(pmd, __pmd((unsigned long)page_address(pte_page)));
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}
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static inline pgd_t *pgd_alloc(struct mm_struct *mm)
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{
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pgd_t *ret = __pgd_alloc(mm, 0);
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if (ret) {
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int num, num2;
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num = USER_PTRS_PER_PGD + USER_KERNEL_GUTTER / PGDIR_SIZE;
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num2 = VMALLOC_SIZE / PGDIR_SIZE;
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memcpy(ret + num, swapper_pg_dir + num, num2 * sizeof(pgd_t));
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}
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return ret;
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}
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#if CONFIG_PGTABLE_LEVELS > 3
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static inline void p4d_populate(struct mm_struct *mm, p4d_t *p4dp, pud_t *pudp)
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{
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set_p4d(p4dp, __p4d((unsigned long)pudp));
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}
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#define __pud_free_tlb(tlb, pmd, addr) pud_free((tlb)->mm, pmd)
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#endif
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#if CONFIG_PGTABLE_LEVELS > 2
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static inline void pud_populate(struct mm_struct *mm, pud_t *pudp, pmd_t *pmdp)
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{
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set_pud(pudp, __pud((unsigned long)pmdp));
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}
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#define __pmd_free_tlb(tlb, pmd, addr) pmd_free((tlb)->mm, pmd)
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#endif
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#define __pte_free_tlb(tlb, pte, addr) pte_free((tlb)->mm, pte)
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#endif /* _ASM_ARC_PGALLOC_H */
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