linux/arch/mips/include/asm/pgalloc.h
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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2.4 KiB
C

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1994 - 2001, 2003 by Ralf Baechle
* Copyright (C) 1999, 2000, 2001 Silicon Graphics, Inc.
*/
#ifndef _ASM_PGALLOC_H
#define _ASM_PGALLOC_H
#include <linux/highmem.h>
#include <linux/mm.h>
#include <linux/sched.h>
#define __HAVE_ARCH_PMD_ALLOC_ONE
#define __HAVE_ARCH_PUD_ALLOC_ONE
#include <asm-generic/pgalloc.h>
static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd,
pte_t *pte)
{
set_pmd(pmd, __pmd((unsigned long)pte));
}
static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
pgtable_t pte)
{
set_pmd(pmd, __pmd((unsigned long)page_address(pte)));
}
/*
* Initialize a new pmd table with invalid pointers.
*/
extern void pmd_init(void *addr);
#ifndef __PAGETABLE_PMD_FOLDED
static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
{
set_pud(pud, __pud((unsigned long)pmd));
}
#endif
/*
* Initialize a new pgd table with invalid pointers.
*/
extern void pgd_init(void *addr);
extern pgd_t *pgd_alloc(struct mm_struct *mm);
#define __pte_free_tlb(tlb, pte, address) \
do { \
pagetable_dtor(page_ptdesc(pte)); \
tlb_remove_page_ptdesc((tlb), page_ptdesc(pte)); \
} while (0)
#ifndef __PAGETABLE_PMD_FOLDED
static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
{
pmd_t *pmd;
struct ptdesc *ptdesc;
ptdesc = pagetable_alloc(GFP_KERNEL_ACCOUNT, PMD_TABLE_ORDER);
if (!ptdesc)
return NULL;
if (!pagetable_pmd_ctor(ptdesc)) {
pagetable_free(ptdesc);
return NULL;
}
pmd = ptdesc_address(ptdesc);
pmd_init(pmd);
return pmd;
}
#define __pmd_free_tlb(tlb, x, addr) pmd_free((tlb)->mm, x)
#endif
#ifndef __PAGETABLE_PUD_FOLDED
static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long address)
{
pud_t *pud;
struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL & ~__GFP_HIGHMEM,
PUD_TABLE_ORDER);
if (!ptdesc)
return NULL;
pagetable_pud_ctor(ptdesc);
pud = ptdesc_address(ptdesc);
pud_init(pud);
return pud;
}
static inline void p4d_populate(struct mm_struct *mm, p4d_t *p4d, pud_t *pud)
{
set_p4d(p4d, __p4d((unsigned long)pud));
}
#define __pud_free_tlb(tlb, x, addr) pud_free((tlb)->mm, x)
#endif /* __PAGETABLE_PUD_FOLDED */
extern void pagetable_init(void);
#endif /* _ASM_PGALLOC_H */