mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson
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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>
68 lines
1.3 KiB
C
68 lines
1.3 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* include/asm-xtensa/pgalloc.h
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*
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* Copyright (C) 2001-2007 Tensilica Inc.
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*/
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#ifndef _XTENSA_PGALLOC_H
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#define _XTENSA_PGALLOC_H
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#ifdef CONFIG_MMU
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#include <linux/highmem.h>
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#include <linux/slab.h>
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#define __HAVE_ARCH_PTE_ALLOC_ONE_KERNEL
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#define __HAVE_ARCH_PTE_ALLOC_ONE
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#include <asm-generic/pgalloc.h>
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/*
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* Allocating and freeing a pmd is trivial: the 1-entry pmd is
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* inside the pgd, so has no extra memory associated with it.
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*/
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#define pmd_populate_kernel(mm, pmdp, ptep) \
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(pmd_val(*(pmdp)) = ((unsigned long)ptep))
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#define pmd_populate(mm, pmdp, page) \
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(pmd_val(*(pmdp)) = ((unsigned long)page_to_virt(page)))
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static inline pgd_t*
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pgd_alloc(struct mm_struct *mm)
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{
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return __pgd_alloc(mm, 0);
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}
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static inline void ptes_clear(pte_t *ptep)
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{
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int i;
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for (i = 0; i < PTRS_PER_PTE; i++)
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pte_clear(NULL, 0, ptep + i);
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}
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static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm)
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{
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pte_t *ptep;
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ptep = (pte_t *)__pte_alloc_one_kernel(mm);
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if (!ptep)
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return NULL;
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ptes_clear(ptep);
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return ptep;
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}
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static inline pgtable_t pte_alloc_one(struct mm_struct *mm)
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{
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struct page *page;
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page = __pte_alloc_one(mm, GFP_PGTABLE_USER);
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if (!page)
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return NULL;
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ptes_clear(page_address(page));
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return page;
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}
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#endif /* CONFIG_MMU */
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#endif /* _XTENSA_PGALLOC_H */
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