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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>
74 lines
1.7 KiB
C
74 lines
1.7 KiB
C
/* SPDX-License-Identifier: GPL-2.0-or-later */
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/*
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* OpenRISC Linux
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*
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* Linux architectural port borrowing liberally from similar works of
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* others. All original copyrights apply as per the original source
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* declaration.
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*
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* OpenRISC implementation:
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* Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
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* Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
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* et al.
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*/
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#ifndef __ASM_OPENRISC_PGALLOC_H
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#define __ASM_OPENRISC_PGALLOC_H
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#include <asm/page.h>
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#include <linux/threads.h>
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#include <linux/mm.h>
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#include <linux/memblock.h>
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#define __HAVE_ARCH_PTE_ALLOC_ONE_KERNEL
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#include <asm-generic/pgalloc.h>
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extern int mem_init_done;
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#define pmd_populate_kernel(mm, pmd, pte) \
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set_pmd(pmd, __pmd(_KERNPG_TABLE + __pa(pte)))
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static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
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struct page *pte)
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{
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set_pmd(pmd, __pmd(_KERNPG_TABLE +
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((unsigned long)page_to_pfn(pte) <<
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(unsigned long) PAGE_SHIFT)));
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}
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/*
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* Allocate and free page tables.
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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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memcpy(ret + USER_PTRS_PER_PGD,
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swapper_pg_dir + USER_PTRS_PER_PGD,
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(PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
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return ret;
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}
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#if 0
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/* FIXME: This seems to be the preferred style, but we are using
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* current_pgd (from mm->pgd) to load kernel pages so we need it
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* initialized. This needs to be looked into.
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*/
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extern inline pgd_t *pgd_alloc(struct mm_struct *mm)
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{
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return (pgd_t *)get_zeroed_page(GFP_KERNEL);
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}
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#endif
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extern pte_t *pte_alloc_one_kernel(struct mm_struct *mm);
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#define __pte_free_tlb(tlb, pte, addr) \
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do { \
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pagetable_dtor(page_ptdesc(pte)); \
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tlb_remove_page_ptdesc((tlb), (page_ptdesc(pte))); \
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} while (0)
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#endif
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