Kevin Brodsky a9b3c355c2 asm-generic: pgalloc: provide generic __pgd_{alloc,free}
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>
2025-01-25 20:22:24 -08:00

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/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
* Copyright (C) 2008-2009 PetaLogix
* Copyright (C) 2006 Atmark Techno, Inc.
*/
#ifndef _ASM_MICROBLAZE_PGALLOC_H
#define _ASM_MICROBLAZE_PGALLOC_H
#include <linux/kernel.h> /* For min/max macros */
#include <linux/highmem.h>
#include <linux/pgtable.h>
#include <asm/setup.h>
#include <asm/io.h>
#include <asm/page.h>
#include <asm/cache.h>
#define __HAVE_ARCH_PTE_ALLOC_ONE_KERNEL
#include <asm-generic/pgalloc.h>
extern void __bad_pte(pmd_t *pmd);
#define pgd_alloc(mm) __pgd_alloc(mm, 0)
extern pte_t *pte_alloc_one_kernel(struct mm_struct *mm);
#define __pte_free_tlb(tlb, pte, addr) pte_free((tlb)->mm, (pte))
#define pmd_populate(mm, pmd, pte) \
(pmd_val(*(pmd)) = (unsigned long)page_address(pte))
#define pmd_populate_kernel(mm, pmd, pte) \
(pmd_val(*(pmd)) = (unsigned long) (pte))
#endif /* _ASM_MICROBLAZE_PGALLOC_H */