// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Copyright 2005, Paul Mackerras, IBM Corporation.
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* Copyright 2009, Benjamin Herrenschmidt, IBM Corporation.
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* Copyright 2015-2016, Aneesh Kumar K.V, IBM Corporation.
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*/
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#include <linux/sched.h>
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#include <linux/memblock.h>
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#include <asm/pgalloc.h>
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#include <asm/tlb.h>
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#include <asm/dma.h>
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#include <mm/mmu_decl.h>
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#ifdef CONFIG_SPARSEMEM_VMEMMAP
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/*
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* On Book3E CPUs, the vmemmap is currently mapped in the top half of
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* the vmalloc space using normal page tables, though the size of
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* pages encoded in the PTEs can be different
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*/
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int __meminit vmemmap_create_mapping(unsigned long start,
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unsigned long page_size,
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unsigned long phys)
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{
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/* Create a PTE encoding without page size */
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unsigned long i, flags = _PAGE_PRESENT | _PAGE_ACCESSED |
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_PAGE_KERNEL_RW;
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/* PTEs only contain page size encodings up to 32M */
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BUG_ON(mmu_psize_defs[mmu_vmemmap_psize].enc > 0xf);
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/* Encode the size in the PTE */
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flags |= mmu_psize_defs[mmu_vmemmap_psize].enc << 8;
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/* For each PTE for that area, map things. Note that we don't
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* increment phys because all PTEs are of the large size and
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* thus must have the low bits clear
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*/
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for (i = 0; i < page_size; i += PAGE_SIZE)
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BUG_ON(map_kernel_page(start + i, phys, __pgprot(flags)));
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return 0;
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}
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#ifdef CONFIG_MEMORY_HOTPLUG
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void vmemmap_remove_mapping(unsigned long start,
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unsigned long page_size)
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{
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}
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#endif
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#endif /* CONFIG_SPARSEMEM_VMEMMAP */
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static void __init *early_alloc_pgtable(unsigned long size)
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{
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void *ptr;
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ptr = memblock_alloc_try_nid(size, size, MEMBLOCK_LOW_LIMIT,
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__pa(MAX_DMA_ADDRESS), NUMA_NO_NODE);
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if (!ptr)
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panic("%s: Failed to allocate %lu bytes align=0x%lx max_addr=%lx\n",
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__func__, size, size, __pa(MAX_DMA_ADDRESS));
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return ptr;
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}
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/*
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* map_kernel_page currently only called by __ioremap
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* map_kernel_page adds an entry to the ioremap page table
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* and adds an entry to the HPT, possibly bolting it
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*/
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int __ref map_kernel_page(unsigned long ea, unsigned long pa, pgprot_t prot)
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{
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pgd_t *pgdp;
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p4d_t *p4dp;
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pud_t *pudp;
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pmd_t *pmdp;
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pte_t *ptep;
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BUILD_BUG_ON(TASK_SIZE_USER64 > PGTABLE_RANGE);
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if (slab_is_available()) {
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pgdp = pgd_offset_k(ea);
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p4dp = p4d_offset(pgdp, ea);
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pudp = pud_alloc(&init_mm, p4dp, ea);
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if (!pudp)
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return -ENOMEM;
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pmdp = pmd_alloc(&init_mm, pudp, ea);
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if (!pmdp)
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return -ENOMEM;
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ptep = pte_alloc_kernel(pmdp, ea);
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if (!ptep)
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return -ENOMEM;
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} else {
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pgdp = pgd_offset_k(ea);
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p4dp = p4d_offset(pgdp, ea);
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if (p4d_none(*p4dp)) {
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pudp = early_alloc_pgtable(PUD_TABLE_SIZE);
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p4d_populate(&init_mm, p4dp, pudp);
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}
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pudp = pud_offset(p4dp, ea);
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if (pud_none(*pudp)) {
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pmdp = early_alloc_pgtable(PMD_TABLE_SIZE);
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pud_populate(&init_mm, pudp, pmdp);
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}
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pmdp = pmd_offset(pudp, ea);
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if (!pmd_present(*pmdp)) {
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ptep = early_alloc_pgtable(PTE_TABLE_SIZE);
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pmd_populate_kernel(&init_mm, pmdp, ptep);
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}
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ptep = pte_offset_kernel(pmdp, ea);
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}
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set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT, prot));
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smp_wmb();
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return 0;
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}
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