91eea67c6d
We need to keep track of the backing pages that get allocated by
vmemmap_populate() so that when we use kdump, the dump-capture kernel knows
where these pages are.
We use a simple linked list of structures that contain the physical address
of the backing page and corresponding virtual address to track the backing
pages.
To save space, we just use a pointer to the next struct vmemmap_backing. We
can also do this because we never remove nodes. We call the pointer "list"
to be compatible with changes made to the crash utility.
vmemmap_populate() is called either at boot-time or on a memory hotplug
operation. We don't have to worry about the boot-time calls because they
will be inherently single-threaded, and for a memory hotplug operation
vmemmap_populate() is called through:
sparse_add_one_section()
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V
kmalloc_section_memmap()
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V
sparse_mem_map_populate()
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V
vmemmap_populate()
and in sparse_add_one_section() we're protected by pgdat_resize_lock().
So, we don't need a spinlock to protect the vmemmap_list.
We allocate space for the vmemmap_backing structs by allocating whole pages
in vmemmap_list_alloc() and then handing out chunks of this to
vmemmap_list_populate().
This means that we waste at most just under one page, but this keeps the code
is simple.
Signed-off-by: Mark Nelson <markn@au1.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
143 lines
4 KiB
C
143 lines
4 KiB
C
#ifndef _ASM_POWERPC_PGALLOC_64_H
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#define _ASM_POWERPC_PGALLOC_64_H
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/*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/slab.h>
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#include <linux/cpumask.h>
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#include <linux/percpu.h>
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struct vmemmap_backing {
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struct vmemmap_backing *list;
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unsigned long phys;
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unsigned long virt_addr;
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};
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/*
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* Functions that deal with pagetables that could be at any level of
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* the table need to be passed an "index_size" so they know how to
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* handle allocation. For PTE pages (which are linked to a struct
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* page for now, and drawn from the main get_free_pages() pool), the
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* allocation size will be (2^index_size * sizeof(pointer)) and
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* allocations are drawn from the kmem_cache in PGT_CACHE(index_size).
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*
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* The maximum index size needs to be big enough to allow any
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* pagetable sizes we need, but small enough to fit in the low bits of
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* any page table pointer. In other words all pagetables, even tiny
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* ones, must be aligned to allow at least enough low 0 bits to
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* contain this value. This value is also used as a mask, so it must
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* be one less than a power of two.
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*/
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#define MAX_PGTABLE_INDEX_SIZE 0xf
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extern struct kmem_cache *pgtable_cache[];
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#define PGT_CACHE(shift) (pgtable_cache[(shift)-1])
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static inline pgd_t *pgd_alloc(struct mm_struct *mm)
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{
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return kmem_cache_alloc(PGT_CACHE(PGD_INDEX_SIZE), GFP_KERNEL);
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}
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static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
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{
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kmem_cache_free(PGT_CACHE(PGD_INDEX_SIZE), pgd);
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}
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#ifndef CONFIG_PPC_64K_PAGES
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#define pgd_populate(MM, PGD, PUD) pgd_set(PGD, PUD)
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static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr)
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{
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return kmem_cache_alloc(PGT_CACHE(PUD_INDEX_SIZE),
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GFP_KERNEL|__GFP_REPEAT);
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}
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static inline void pud_free(struct mm_struct *mm, pud_t *pud)
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{
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kmem_cache_free(PGT_CACHE(PUD_INDEX_SIZE), pud);
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}
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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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pud_set(pud, (unsigned long)pmd);
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}
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#define pmd_populate(mm, pmd, pte_page) \
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pmd_populate_kernel(mm, pmd, page_address(pte_page))
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#define pmd_populate_kernel(mm, pmd, pte) pmd_set(pmd, (unsigned long)(pte))
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#define pmd_pgtable(pmd) pmd_page(pmd)
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#else /* CONFIG_PPC_64K_PAGES */
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#define pud_populate(mm, pud, pmd) pud_set(pud, (unsigned long)pmd)
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static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd,
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pte_t *pte)
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{
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pmd_set(pmd, (unsigned long)pte);
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}
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#define pmd_populate(mm, pmd, pte_page) \
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pmd_populate_kernel(mm, pmd, page_address(pte_page))
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#define pmd_pgtable(pmd) pmd_page(pmd)
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#endif /* CONFIG_PPC_64K_PAGES */
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static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
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{
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return kmem_cache_alloc(PGT_CACHE(PMD_INDEX_SIZE),
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GFP_KERNEL|__GFP_REPEAT);
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}
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static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
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{
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kmem_cache_free(PGT_CACHE(PMD_INDEX_SIZE), pmd);
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}
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static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm,
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unsigned long address)
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{
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return (pte_t *)__get_free_page(GFP_KERNEL | __GFP_REPEAT | __GFP_ZERO);
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}
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static inline pgtable_t pte_alloc_one(struct mm_struct *mm,
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unsigned long address)
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{
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struct page *page;
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pte_t *pte;
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pte = pte_alloc_one_kernel(mm, address);
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if (!pte)
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return NULL;
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page = virt_to_page(pte);
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pgtable_page_ctor(page);
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return page;
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}
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static inline void pgtable_free(void *table, unsigned index_size)
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{
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if (!index_size)
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free_page((unsigned long)table);
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else {
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BUG_ON(index_size > MAX_PGTABLE_INDEX_SIZE);
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kmem_cache_free(PGT_CACHE(index_size), table);
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}
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}
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#define __pmd_free_tlb(tlb, pmd, addr) \
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pgtable_free_tlb(tlb, pmd, PMD_INDEX_SIZE)
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#ifndef CONFIG_PPC_64K_PAGES
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#define __pud_free_tlb(tlb, pud, addr) \
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pgtable_free_tlb(tlb, pud, PUD_INDEX_SIZE)
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#endif /* CONFIG_PPC_64K_PAGES */
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#define check_pgt_cache() do { } while (0)
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#endif /* _ASM_POWERPC_PGALLOC_64_H */
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