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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>
159 lines
3.8 KiB
C
159 lines
3.8 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* Copyright (C) 2009 Chen Liqin <liqin.chen@sunplusct.com>
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* Copyright (C) 2012 Regents of the University of California
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*/
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#ifndef _ASM_RISCV_PGALLOC_H
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#define _ASM_RISCV_PGALLOC_H
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#include <linux/mm.h>
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#include <asm/sbi.h>
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#include <asm/tlb.h>
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#ifdef CONFIG_MMU
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#define __HAVE_ARCH_PUD_FREE
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#include <asm-generic/pgalloc.h>
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/*
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* While riscv platforms with riscv_ipi_for_rfence as true require an IPI to
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* perform TLB shootdown, some platforms with riscv_ipi_for_rfence as false use
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* SBI to perform TLB shootdown. To keep software pagetable walkers safe in this
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* case we switch to RCU based table free (MMU_GATHER_RCU_TABLE_FREE). See the
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* comment below 'ifdef CONFIG_MMU_GATHER_RCU_TABLE_FREE' in include/asm-generic/tlb.h
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* for more details.
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*/
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static inline void riscv_tlb_remove_ptdesc(struct mmu_gather *tlb, void *pt)
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{
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if (riscv_use_sbi_for_rfence()) {
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tlb_remove_ptdesc(tlb, pt);
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} else {
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pagetable_dtor(pt);
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tlb_remove_page_ptdesc(tlb, pt);
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}
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}
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static inline void pmd_populate_kernel(struct mm_struct *mm,
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pmd_t *pmd, pte_t *pte)
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{
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unsigned long pfn = virt_to_pfn(pte);
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set_pmd(pmd, __pmd((pfn << _PAGE_PFN_SHIFT) | _PAGE_TABLE));
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}
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static inline void pmd_populate(struct mm_struct *mm,
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pmd_t *pmd, pgtable_t pte)
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{
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unsigned long pfn = virt_to_pfn(page_address(pte));
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set_pmd(pmd, __pmd((pfn << _PAGE_PFN_SHIFT) | _PAGE_TABLE));
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}
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#ifndef __PAGETABLE_PMD_FOLDED
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static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
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{
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unsigned long pfn = virt_to_pfn(pmd);
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set_pud(pud, __pud((pfn << _PAGE_PFN_SHIFT) | _PAGE_TABLE));
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}
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static inline void p4d_populate(struct mm_struct *mm, p4d_t *p4d, pud_t *pud)
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{
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if (pgtable_l4_enabled) {
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unsigned long pfn = virt_to_pfn(pud);
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set_p4d(p4d, __p4d((pfn << _PAGE_PFN_SHIFT) | _PAGE_TABLE));
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}
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}
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static inline void p4d_populate_safe(struct mm_struct *mm, p4d_t *p4d,
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pud_t *pud)
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{
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if (pgtable_l4_enabled) {
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unsigned long pfn = virt_to_pfn(pud);
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set_p4d_safe(p4d,
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__p4d((pfn << _PAGE_PFN_SHIFT) | _PAGE_TABLE));
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}
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}
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static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd, p4d_t *p4d)
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{
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if (pgtable_l5_enabled) {
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unsigned long pfn = virt_to_pfn(p4d);
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set_pgd(pgd, __pgd((pfn << _PAGE_PFN_SHIFT) | _PAGE_TABLE));
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}
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}
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static inline void pgd_populate_safe(struct mm_struct *mm, pgd_t *pgd,
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p4d_t *p4d)
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{
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if (pgtable_l5_enabled) {
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unsigned long pfn = virt_to_pfn(p4d);
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set_pgd_safe(pgd,
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__pgd((pfn << _PAGE_PFN_SHIFT) | _PAGE_TABLE));
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}
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}
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#define pud_free pud_free
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static inline void pud_free(struct mm_struct *mm, pud_t *pud)
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{
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if (pgtable_l4_enabled)
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__pud_free(mm, pud);
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}
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static inline void __pud_free_tlb(struct mmu_gather *tlb, pud_t *pud,
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unsigned long addr)
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{
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if (pgtable_l4_enabled)
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riscv_tlb_remove_ptdesc(tlb, virt_to_ptdesc(pud));
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}
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static inline void __p4d_free_tlb(struct mmu_gather *tlb, p4d_t *p4d,
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unsigned long addr)
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{
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if (pgtable_l5_enabled)
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riscv_tlb_remove_ptdesc(tlb, virt_to_ptdesc(p4d));
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}
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#endif /* __PAGETABLE_PMD_FOLDED */
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static inline void sync_kernel_mappings(pgd_t *pgd)
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{
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memcpy(pgd + USER_PTRS_PER_PGD,
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init_mm.pgd + USER_PTRS_PER_PGD,
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(PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
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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 *pgd;
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pgd = __pgd_alloc(mm, 0);
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if (likely(pgd != NULL)) {
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/* Copy kernel mappings */
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sync_kernel_mappings(pgd);
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}
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return pgd;
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}
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#ifndef __PAGETABLE_PMD_FOLDED
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static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd,
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unsigned long addr)
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{
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riscv_tlb_remove_ptdesc(tlb, virt_to_ptdesc(pmd));
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}
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#endif /* __PAGETABLE_PMD_FOLDED */
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static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte,
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unsigned long addr)
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{
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riscv_tlb_remove_ptdesc(tlb, page_ptdesc(pte));
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}
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#endif /* CONFIG_MMU */
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#endif /* _ASM_RISCV_PGALLOC_H */
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