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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>
53 lines
1.2 KiB
C
53 lines
1.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/* sun3_pgalloc.h --
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* reorganization around 2.3.39, routines moved from sun3_pgtable.h
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*
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*
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* 02/27/2002 -- Modified to support "highpte" implementation in 2.5.5 (Sam)
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*
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* moved 1/26/2000 Sam Creasey
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*/
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#ifndef _SUN3_PGALLOC_H
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#define _SUN3_PGALLOC_H
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#include <asm/tlb.h>
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#include <asm-generic/pgalloc.h>
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extern const char bad_pmd_string[];
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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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static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd, pte_t *pte)
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{
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pmd_val(*pmd) = __pa((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 page)
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{
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pmd_val(*pmd) = __pa((unsigned long)page_address(page));
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}
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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_free(mm, x) do { } while (0)
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static inline pgd_t * pgd_alloc(struct mm_struct *mm)
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{
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pgd_t *new_pgd;
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new_pgd = __pgd_alloc(mm, 0);
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memcpy(new_pgd, swapper_pg_dir, PAGE_SIZE);
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memset(new_pgd, 0, (PAGE_OFFSET >> PGDIR_SHIFT));
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return new_pgd;
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}
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#endif /* SUN3_PGALLOC_H */
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