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4574815abf
As very well explained in commit20a004e7b0("arm64: mm: Use READ_ONCE/WRITE_ONCE when accessing page tables"), an architecture whose page table walker can modify the PTE in parallel must use READ_ONCE()/ WRITE_ONCE() macro to avoid any compiler transformation. So apply that to LoongArch which is such an architecture, in order to avoid potential problems. Similar to commitedf9556472("riscv: Use accessors to page table entries instead of direct dereference"). Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
272 lines
6.4 KiB
C
272 lines
6.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
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*/
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#include <linux/init.h>
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#include <linux/export.h>
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#include <linux/signal.h>
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#include <linux/sched.h>
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#include <linux/smp.h>
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/string.h>
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#include <linux/types.h>
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#include <linux/pagemap.h>
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#include <linux/memblock.h>
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#include <linux/memremap.h>
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#include <linux/mm.h>
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#include <linux/mman.h>
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#include <linux/highmem.h>
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#include <linux/swap.h>
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#include <linux/proc_fs.h>
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#include <linux/pfn.h>
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#include <linux/hardirq.h>
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#include <linux/gfp.h>
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#include <linux/hugetlb.h>
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#include <linux/mmzone.h>
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#include <linux/execmem.h>
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#include <asm/asm-offsets.h>
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#include <asm/bootinfo.h>
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#include <asm/cpu.h>
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#include <asm/dma.h>
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#include <asm/mmu_context.h>
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#include <asm/sections.h>
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#include <asm/pgtable.h>
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#include <asm/pgalloc.h>
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#include <asm/tlb.h>
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unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss;
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EXPORT_SYMBOL(empty_zero_page);
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void copy_user_highpage(struct page *to, struct page *from,
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unsigned long vaddr, struct vm_area_struct *vma)
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{
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void *vfrom, *vto;
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vfrom = kmap_local_page(from);
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vto = kmap_local_page(to);
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copy_page(vto, vfrom);
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kunmap_local(vfrom);
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kunmap_local(vto);
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/* Make sure this page is cleared on other CPU's too before using it */
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smp_wmb();
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}
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int __ref page_is_ram(unsigned long pfn)
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{
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unsigned long addr = PFN_PHYS(pfn);
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return memblock_is_memory(addr) && !memblock_is_reserved(addr);
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}
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#ifndef CONFIG_NUMA
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void __init paging_init(void)
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{
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unsigned long max_zone_pfns[MAX_NR_ZONES];
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#ifdef CONFIG_ZONE_DMA
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max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
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#endif
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#ifdef CONFIG_ZONE_DMA32
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max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
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#endif
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max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
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free_area_init(max_zone_pfns);
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}
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void __init mem_init(void)
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{
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max_mapnr = max_low_pfn;
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high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
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memblock_free_all();
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}
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#endif /* !CONFIG_NUMA */
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void __ref free_initmem(void)
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{
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free_initmem_default(POISON_FREE_INITMEM);
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}
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#ifdef CONFIG_MEMORY_HOTPLUG
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int arch_add_memory(int nid, u64 start, u64 size, struct mhp_params *params)
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{
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unsigned long start_pfn = start >> PAGE_SHIFT;
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unsigned long nr_pages = size >> PAGE_SHIFT;
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int ret;
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ret = __add_pages(nid, start_pfn, nr_pages, params);
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if (ret)
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pr_warn("%s: Problem encountered in __add_pages() as ret=%d\n",
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__func__, ret);
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return ret;
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}
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void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
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{
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unsigned long start_pfn = start >> PAGE_SHIFT;
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unsigned long nr_pages = size >> PAGE_SHIFT;
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struct page *page = pfn_to_page(start_pfn);
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/* With altmap the first mapped page is offset from @start */
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if (altmap)
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page += vmem_altmap_offset(altmap);
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__remove_pages(start_pfn, nr_pages, altmap);
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}
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#ifdef CONFIG_NUMA
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int memory_add_physaddr_to_nid(u64 start)
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{
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return pa_to_nid(start);
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}
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EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
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#endif
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#endif
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#ifdef CONFIG_SPARSEMEM_VMEMMAP
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void __meminit vmemmap_set_pmd(pmd_t *pmd, void *p, int node,
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unsigned long addr, unsigned long next)
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{
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pmd_t entry;
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entry = pfn_pmd(virt_to_pfn(p), PAGE_KERNEL);
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pmd_val(entry) |= _PAGE_HUGE | _PAGE_HGLOBAL;
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set_pmd_at(&init_mm, addr, pmd, entry);
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}
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int __meminit vmemmap_check_pmd(pmd_t *pmd, int node,
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unsigned long addr, unsigned long next)
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{
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int huge = pmd_val(pmdp_get(pmd)) & _PAGE_HUGE;
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if (huge)
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vmemmap_verify((pte_t *)pmd, node, addr, next);
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return huge;
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}
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int __meminit vmemmap_populate(unsigned long start, unsigned long end,
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int node, struct vmem_altmap *altmap)
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{
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#if CONFIG_PGTABLE_LEVELS == 2
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return vmemmap_populate_basepages(start, end, node, NULL);
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#else
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return vmemmap_populate_hugepages(start, end, node, NULL);
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#endif
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}
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#ifdef CONFIG_MEMORY_HOTPLUG
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void vmemmap_free(unsigned long start, unsigned long end, struct vmem_altmap *altmap)
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{
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}
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#endif
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#endif
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pte_t * __init populate_kernel_pte(unsigned long addr)
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{
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pgd_t *pgd = pgd_offset_k(addr);
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p4d_t *p4d = p4d_offset(pgd, addr);
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pud_t *pud;
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pmd_t *pmd;
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if (p4d_none(p4dp_get(p4d))) {
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pud = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
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if (!pud)
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panic("%s: Failed to allocate memory\n", __func__);
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p4d_populate(&init_mm, p4d, pud);
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#ifndef __PAGETABLE_PUD_FOLDED
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pud_init(pud);
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#endif
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}
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pud = pud_offset(p4d, addr);
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if (pud_none(pudp_get(pud))) {
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pmd = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
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if (!pmd)
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panic("%s: Failed to allocate memory\n", __func__);
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pud_populate(&init_mm, pud, pmd);
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#ifndef __PAGETABLE_PMD_FOLDED
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pmd_init(pmd);
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#endif
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}
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pmd = pmd_offset(pud, addr);
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if (!pmd_present(pmdp_get(pmd))) {
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pte_t *pte;
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pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
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if (!pte)
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panic("%s: Failed to allocate memory\n", __func__);
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pmd_populate_kernel(&init_mm, pmd, pte);
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}
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return pte_offset_kernel(pmd, addr);
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}
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void __init __set_fixmap(enum fixed_addresses idx,
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phys_addr_t phys, pgprot_t flags)
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{
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unsigned long addr = __fix_to_virt(idx);
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pte_t *ptep;
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BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
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ptep = populate_kernel_pte(addr);
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if (!pte_none(ptep_get(ptep))) {
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pte_ERROR(*ptep);
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return;
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}
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if (pgprot_val(flags))
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set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, flags));
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else {
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pte_clear(&init_mm, addr, ptep);
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flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
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}
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}
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/*
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* Align swapper_pg_dir in to 64K, allows its address to be loaded
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* with a single LUI instruction in the TLB handlers. If we used
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* __aligned(64K), its size would get rounded up to the alignment
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* size, and waste space. So we place it in its own section and align
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* it in the linker script.
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*/
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pgd_t swapper_pg_dir[_PTRS_PER_PGD] __section(".bss..swapper_pg_dir");
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pgd_t invalid_pg_dir[_PTRS_PER_PGD] __page_aligned_bss;
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#ifndef __PAGETABLE_PUD_FOLDED
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pud_t invalid_pud_table[PTRS_PER_PUD] __page_aligned_bss;
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EXPORT_SYMBOL(invalid_pud_table);
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#endif
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#ifndef __PAGETABLE_PMD_FOLDED
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pmd_t invalid_pmd_table[PTRS_PER_PMD] __page_aligned_bss;
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EXPORT_SYMBOL(invalid_pmd_table);
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#endif
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pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned_bss;
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EXPORT_SYMBOL(invalid_pte_table);
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#ifdef CONFIG_EXECMEM
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static struct execmem_info execmem_info __ro_after_init;
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struct execmem_info __init *execmem_arch_setup(void)
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{
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execmem_info = (struct execmem_info){
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.ranges = {
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[EXECMEM_DEFAULT] = {
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.start = MODULES_VADDR,
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.end = MODULES_END,
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.pgprot = PAGE_KERNEL,
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.alignment = 1,
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},
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},
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};
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return &execmem_info;
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}
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#endif /* CONFIG_EXECMEM */
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