593 lines
14 KiB
C
593 lines
14 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright IBM Corp. 2006
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* Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
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*/
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#include <linux/memory_hotplug.h>
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#include <linux/memblock.h>
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#include <linux/pfn.h>
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#include <linux/mm.h>
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#include <linux/init.h>
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#include <linux/list.h>
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#include <linux/hugetlb.h>
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#include <linux/slab.h>
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#include <asm/cacheflush.h>
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#include <asm/pgalloc.h>
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#include <asm/setup.h>
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#include <asm/tlbflush.h>
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#include <asm/sections.h>
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#include <asm/set_memory.h>
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static DEFINE_MUTEX(vmem_mutex);
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static void __ref *vmem_alloc_pages(unsigned int order)
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{
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unsigned long size = PAGE_SIZE << order;
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if (slab_is_available())
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return (void *)__get_free_pages(GFP_KERNEL, order);
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return memblock_alloc(size, size);
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}
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static void vmem_free_pages(unsigned long addr, int order)
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{
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/* We don't expect boot memory to be removed ever. */
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if (!slab_is_available() ||
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WARN_ON_ONCE(PageReserved(virt_to_page(addr))))
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return;
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free_pages(addr, order);
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}
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void *vmem_crst_alloc(unsigned long val)
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{
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unsigned long *table;
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table = vmem_alloc_pages(CRST_ALLOC_ORDER);
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if (table)
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crst_table_init(table, val);
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return table;
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}
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pte_t __ref *vmem_pte_alloc(void)
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{
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unsigned long size = PTRS_PER_PTE * sizeof(pte_t);
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pte_t *pte;
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if (slab_is_available())
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pte = (pte_t *) page_table_alloc(&init_mm);
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else
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pte = (pte_t *) memblock_alloc(size, size);
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if (!pte)
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return NULL;
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memset64((u64 *)pte, _PAGE_INVALID, PTRS_PER_PTE);
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return pte;
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}
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static void vmem_pte_free(unsigned long *table)
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{
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/* We don't expect boot memory to be removed ever. */
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if (!slab_is_available() ||
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WARN_ON_ONCE(PageReserved(virt_to_page(table))))
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return;
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page_table_free(&init_mm, table);
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}
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#define PAGE_UNUSED 0xFD
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/*
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* The unused vmemmap range, which was not yet memset(PAGE_UNUSED) ranges
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* from unused_sub_pmd_start to next PMD_SIZE boundary.
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*/
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static unsigned long unused_sub_pmd_start;
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static void vmemmap_flush_unused_sub_pmd(void)
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{
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if (!unused_sub_pmd_start)
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return;
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memset((void *)unused_sub_pmd_start, PAGE_UNUSED,
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ALIGN(unused_sub_pmd_start, PMD_SIZE) - unused_sub_pmd_start);
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unused_sub_pmd_start = 0;
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}
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static void vmemmap_mark_sub_pmd_used(unsigned long start, unsigned long end)
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{
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/*
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* As we expect to add in the same granularity as we remove, it's
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* sufficient to mark only some piece used to block the memmap page from
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* getting removed (just in case the memmap never gets initialized,
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* e.g., because the memory block never gets onlined).
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*/
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memset((void *)start, 0, sizeof(struct page));
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}
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static void vmemmap_use_sub_pmd(unsigned long start, unsigned long end)
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{
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/*
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* We only optimize if the new used range directly follows the
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* previously unused range (esp., when populating consecutive sections).
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*/
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if (unused_sub_pmd_start == start) {
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unused_sub_pmd_start = end;
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if (likely(IS_ALIGNED(unused_sub_pmd_start, PMD_SIZE)))
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unused_sub_pmd_start = 0;
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return;
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}
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vmemmap_flush_unused_sub_pmd();
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vmemmap_mark_sub_pmd_used(start, end);
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}
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static void vmemmap_use_new_sub_pmd(unsigned long start, unsigned long end)
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{
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unsigned long page = ALIGN_DOWN(start, PMD_SIZE);
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vmemmap_flush_unused_sub_pmd();
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/* Could be our memmap page is filled with PAGE_UNUSED already ... */
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vmemmap_mark_sub_pmd_used(start, end);
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/* Mark the unused parts of the new memmap page PAGE_UNUSED. */
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if (!IS_ALIGNED(start, PMD_SIZE))
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memset((void *)page, PAGE_UNUSED, start - page);
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/*
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* We want to avoid memset(PAGE_UNUSED) when populating the vmemmap of
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* consecutive sections. Remember for the last added PMD the last
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* unused range in the populated PMD.
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*/
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if (!IS_ALIGNED(end, PMD_SIZE))
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unused_sub_pmd_start = end;
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}
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/* Returns true if the PMD is completely unused and can be freed. */
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static bool vmemmap_unuse_sub_pmd(unsigned long start, unsigned long end)
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{
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unsigned long page = ALIGN_DOWN(start, PMD_SIZE);
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vmemmap_flush_unused_sub_pmd();
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memset((void *)start, PAGE_UNUSED, end - start);
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return !memchr_inv((void *)page, PAGE_UNUSED, PMD_SIZE);
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}
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/* __ref: we'll only call vmemmap_alloc_block() via vmemmap_populate() */
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static int __ref modify_pte_table(pmd_t *pmd, unsigned long addr,
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unsigned long end, bool add, bool direct)
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{
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unsigned long prot, pages = 0;
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int ret = -ENOMEM;
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pte_t *pte;
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prot = pgprot_val(PAGE_KERNEL);
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if (!MACHINE_HAS_NX)
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prot &= ~_PAGE_NOEXEC;
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pte = pte_offset_kernel(pmd, addr);
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for (; addr < end; addr += PAGE_SIZE, pte++) {
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if (!add) {
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if (pte_none(*pte))
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continue;
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if (!direct)
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vmem_free_pages((unsigned long) pfn_to_virt(pte_pfn(*pte)), 0);
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pte_clear(&init_mm, addr, pte);
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} else if (pte_none(*pte)) {
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if (!direct) {
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void *new_page = vmemmap_alloc_block(PAGE_SIZE, NUMA_NO_NODE);
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if (!new_page)
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goto out;
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pte_val(*pte) = __pa(new_page) | prot;
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} else {
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pte_val(*pte) = __pa(addr) | prot;
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}
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} else {
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continue;
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}
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pages++;
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}
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ret = 0;
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out:
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if (direct)
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update_page_count(PG_DIRECT_MAP_4K, add ? pages : -pages);
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return ret;
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}
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static void try_free_pte_table(pmd_t *pmd, unsigned long start)
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{
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pte_t *pte;
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int i;
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/* We can safely assume this is fully in 1:1 mapping & vmemmap area */
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pte = pte_offset_kernel(pmd, start);
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for (i = 0; i < PTRS_PER_PTE; i++, pte++) {
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if (!pte_none(*pte))
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return;
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}
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vmem_pte_free((unsigned long *) pmd_deref(*pmd));
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pmd_clear(pmd);
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}
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/* __ref: we'll only call vmemmap_alloc_block() via vmemmap_populate() */
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static int __ref modify_pmd_table(pud_t *pud, unsigned long addr,
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unsigned long end, bool add, bool direct)
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{
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unsigned long next, prot, pages = 0;
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int ret = -ENOMEM;
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pmd_t *pmd;
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pte_t *pte;
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prot = pgprot_val(SEGMENT_KERNEL);
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if (!MACHINE_HAS_NX)
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prot &= ~_SEGMENT_ENTRY_NOEXEC;
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pmd = pmd_offset(pud, addr);
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for (; addr < end; addr = next, pmd++) {
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next = pmd_addr_end(addr, end);
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if (!add) {
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if (pmd_none(*pmd))
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continue;
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if (pmd_large(*pmd)) {
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if (IS_ALIGNED(addr, PMD_SIZE) &&
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IS_ALIGNED(next, PMD_SIZE)) {
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if (!direct)
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vmem_free_pages(pmd_deref(*pmd), get_order(PMD_SIZE));
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pmd_clear(pmd);
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pages++;
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} else if (!direct && vmemmap_unuse_sub_pmd(addr, next)) {
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vmem_free_pages(pmd_deref(*pmd), get_order(PMD_SIZE));
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pmd_clear(pmd);
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}
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continue;
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}
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} else if (pmd_none(*pmd)) {
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if (IS_ALIGNED(addr, PMD_SIZE) &&
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IS_ALIGNED(next, PMD_SIZE) &&
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MACHINE_HAS_EDAT1 && addr && direct &&
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!debug_pagealloc_enabled()) {
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pmd_val(*pmd) = __pa(addr) | prot;
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pages++;
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continue;
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} else if (!direct && MACHINE_HAS_EDAT1) {
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void *new_page;
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/*
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* Use 1MB frames for vmemmap if available. We
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* always use large frames even if they are only
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* partially used. Otherwise we would have also
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* page tables since vmemmap_populate gets
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* called for each section separately.
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*/
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new_page = vmemmap_alloc_block(PMD_SIZE, NUMA_NO_NODE);
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if (new_page) {
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pmd_val(*pmd) = __pa(new_page) | prot;
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if (!IS_ALIGNED(addr, PMD_SIZE) ||
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!IS_ALIGNED(next, PMD_SIZE)) {
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vmemmap_use_new_sub_pmd(addr, next);
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}
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continue;
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}
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}
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pte = vmem_pte_alloc();
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if (!pte)
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goto out;
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pmd_populate(&init_mm, pmd, pte);
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} else if (pmd_large(*pmd)) {
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if (!direct)
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vmemmap_use_sub_pmd(addr, next);
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continue;
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}
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ret = modify_pte_table(pmd, addr, next, add, direct);
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if (ret)
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goto out;
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if (!add)
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try_free_pte_table(pmd, addr & PMD_MASK);
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}
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ret = 0;
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out:
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if (direct)
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update_page_count(PG_DIRECT_MAP_1M, add ? pages : -pages);
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return ret;
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}
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static void try_free_pmd_table(pud_t *pud, unsigned long start)
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{
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const unsigned long end = start + PUD_SIZE;
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pmd_t *pmd;
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int i;
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/* Don't mess with any tables not fully in 1:1 mapping & vmemmap area */
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if (end > VMALLOC_START)
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return;
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#ifdef CONFIG_KASAN
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if (start < KASAN_SHADOW_END && KASAN_SHADOW_START > end)
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return;
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#endif
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pmd = pmd_offset(pud, start);
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for (i = 0; i < PTRS_PER_PMD; i++, pmd++)
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if (!pmd_none(*pmd))
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return;
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vmem_free_pages(pud_deref(*pud), CRST_ALLOC_ORDER);
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pud_clear(pud);
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}
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static int modify_pud_table(p4d_t *p4d, unsigned long addr, unsigned long end,
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bool add, bool direct)
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{
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unsigned long next, prot, pages = 0;
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int ret = -ENOMEM;
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pud_t *pud;
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pmd_t *pmd;
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prot = pgprot_val(REGION3_KERNEL);
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if (!MACHINE_HAS_NX)
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prot &= ~_REGION_ENTRY_NOEXEC;
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pud = pud_offset(p4d, addr);
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for (; addr < end; addr = next, pud++) {
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next = pud_addr_end(addr, end);
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if (!add) {
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if (pud_none(*pud))
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continue;
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if (pud_large(*pud)) {
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if (IS_ALIGNED(addr, PUD_SIZE) &&
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IS_ALIGNED(next, PUD_SIZE)) {
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pud_clear(pud);
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pages++;
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}
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continue;
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}
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} else if (pud_none(*pud)) {
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if (IS_ALIGNED(addr, PUD_SIZE) &&
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IS_ALIGNED(next, PUD_SIZE) &&
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MACHINE_HAS_EDAT2 && addr && direct &&
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!debug_pagealloc_enabled()) {
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pud_val(*pud) = __pa(addr) | prot;
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pages++;
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continue;
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}
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pmd = vmem_crst_alloc(_SEGMENT_ENTRY_EMPTY);
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if (!pmd)
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goto out;
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pud_populate(&init_mm, pud, pmd);
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} else if (pud_large(*pud)) {
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continue;
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}
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ret = modify_pmd_table(pud, addr, next, add, direct);
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if (ret)
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goto out;
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if (!add)
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try_free_pmd_table(pud, addr & PUD_MASK);
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}
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ret = 0;
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out:
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if (direct)
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update_page_count(PG_DIRECT_MAP_2G, add ? pages : -pages);
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return ret;
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}
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static void try_free_pud_table(p4d_t *p4d, unsigned long start)
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{
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const unsigned long end = start + P4D_SIZE;
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pud_t *pud;
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int i;
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/* Don't mess with any tables not fully in 1:1 mapping & vmemmap area */
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if (end > VMALLOC_START)
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return;
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#ifdef CONFIG_KASAN
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if (start < KASAN_SHADOW_END && KASAN_SHADOW_START > end)
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return;
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#endif
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pud = pud_offset(p4d, start);
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for (i = 0; i < PTRS_PER_PUD; i++, pud++) {
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if (!pud_none(*pud))
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return;
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}
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vmem_free_pages(p4d_deref(*p4d), CRST_ALLOC_ORDER);
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p4d_clear(p4d);
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}
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static int modify_p4d_table(pgd_t *pgd, unsigned long addr, unsigned long end,
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bool add, bool direct)
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{
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unsigned long next;
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int ret = -ENOMEM;
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p4d_t *p4d;
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pud_t *pud;
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p4d = p4d_offset(pgd, addr);
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for (; addr < end; addr = next, p4d++) {
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next = p4d_addr_end(addr, end);
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if (!add) {
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if (p4d_none(*p4d))
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continue;
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} else if (p4d_none(*p4d)) {
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pud = vmem_crst_alloc(_REGION3_ENTRY_EMPTY);
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if (!pud)
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goto out;
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p4d_populate(&init_mm, p4d, pud);
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}
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ret = modify_pud_table(p4d, addr, next, add, direct);
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if (ret)
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goto out;
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if (!add)
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try_free_pud_table(p4d, addr & P4D_MASK);
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}
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ret = 0;
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out:
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return ret;
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}
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static void try_free_p4d_table(pgd_t *pgd, unsigned long start)
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{
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const unsigned long end = start + PGDIR_SIZE;
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p4d_t *p4d;
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int i;
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/* Don't mess with any tables not fully in 1:1 mapping & vmemmap area */
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if (end > VMALLOC_START)
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return;
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#ifdef CONFIG_KASAN
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if (start < KASAN_SHADOW_END && KASAN_SHADOW_START > end)
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return;
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#endif
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p4d = p4d_offset(pgd, start);
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for (i = 0; i < PTRS_PER_P4D; i++, p4d++) {
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if (!p4d_none(*p4d))
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return;
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}
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vmem_free_pages(pgd_deref(*pgd), CRST_ALLOC_ORDER);
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pgd_clear(pgd);
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}
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static int modify_pagetable(unsigned long start, unsigned long end, bool add,
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bool direct)
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{
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unsigned long addr, next;
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int ret = -ENOMEM;
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pgd_t *pgd;
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p4d_t *p4d;
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if (WARN_ON_ONCE(!PAGE_ALIGNED(start | end)))
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return -EINVAL;
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for (addr = start; addr < end; addr = next) {
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next = pgd_addr_end(addr, end);
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pgd = pgd_offset_k(addr);
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if (!add) {
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if (pgd_none(*pgd))
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continue;
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} else if (pgd_none(*pgd)) {
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p4d = vmem_crst_alloc(_REGION2_ENTRY_EMPTY);
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if (!p4d)
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goto out;
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pgd_populate(&init_mm, pgd, p4d);
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}
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ret = modify_p4d_table(pgd, addr, next, add, direct);
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if (ret)
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goto out;
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if (!add)
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try_free_p4d_table(pgd, addr & PGDIR_MASK);
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}
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ret = 0;
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out:
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if (!add)
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flush_tlb_kernel_range(start, end);
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return ret;
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}
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static int add_pagetable(unsigned long start, unsigned long end, bool direct)
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{
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return modify_pagetable(start, end, true, direct);
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}
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static int remove_pagetable(unsigned long start, unsigned long end, bool direct)
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{
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return modify_pagetable(start, end, false, direct);
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}
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/*
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* Add a physical memory range to the 1:1 mapping.
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*/
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static int vmem_add_range(unsigned long start, unsigned long size)
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{
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return add_pagetable(start, start + size, true);
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}
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/*
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* Remove a physical memory range from the 1:1 mapping.
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*/
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static void vmem_remove_range(unsigned long start, unsigned long size)
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{
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remove_pagetable(start, start + size, true);
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}
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/*
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* Add a backed mem_map array to the virtual mem_map array.
|
|
*/
|
|
int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
|
|
struct vmem_altmap *altmap)
|
|
{
|
|
int ret;
|
|
|
|
mutex_lock(&vmem_mutex);
|
|
/* We don't care about the node, just use NUMA_NO_NODE on allocations */
|
|
ret = add_pagetable(start, end, false);
|
|
if (ret)
|
|
remove_pagetable(start, end, false);
|
|
mutex_unlock(&vmem_mutex);
|
|
return ret;
|
|
}
|
|
|
|
void vmemmap_free(unsigned long start, unsigned long end,
|
|
struct vmem_altmap *altmap)
|
|
{
|
|
mutex_lock(&vmem_mutex);
|
|
remove_pagetable(start, end, false);
|
|
mutex_unlock(&vmem_mutex);
|
|
}
|
|
|
|
void vmem_remove_mapping(unsigned long start, unsigned long size)
|
|
{
|
|
mutex_lock(&vmem_mutex);
|
|
vmem_remove_range(start, size);
|
|
mutex_unlock(&vmem_mutex);
|
|
}
|
|
|
|
struct range arch_get_mappable_range(void)
|
|
{
|
|
struct range mhp_range;
|
|
|
|
mhp_range.start = 0;
|
|
mhp_range.end = VMEM_MAX_PHYS - 1;
|
|
return mhp_range;
|
|
}
|
|
|
|
int vmem_add_mapping(unsigned long start, unsigned long size)
|
|
{
|
|
struct range range = arch_get_mappable_range();
|
|
int ret;
|
|
|
|
if (start < range.start ||
|
|
start + size > range.end + 1 ||
|
|
start + size < start)
|
|
return -ERANGE;
|
|
|
|
mutex_lock(&vmem_mutex);
|
|
ret = vmem_add_range(start, size);
|
|
if (ret)
|
|
vmem_remove_range(start, size);
|
|
mutex_unlock(&vmem_mutex);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* map whole physical memory to virtual memory (identity mapping)
|
|
* we reserve enough space in the vmalloc area for vmemmap to hotplug
|
|
* additional memory segments.
|
|
*/
|
|
void __init vmem_map_init(void)
|
|
{
|
|
phys_addr_t base, end;
|
|
u64 i;
|
|
|
|
for_each_mem_range(i, &base, &end)
|
|
vmem_add_range(base, end - base);
|
|
__set_memory((unsigned long)_stext,
|
|
(unsigned long)(_etext - _stext) >> PAGE_SHIFT,
|
|
SET_MEMORY_RO | SET_MEMORY_X);
|
|
__set_memory((unsigned long)_etext,
|
|
(unsigned long)(__end_rodata - _etext) >> PAGE_SHIFT,
|
|
SET_MEMORY_RO);
|
|
__set_memory((unsigned long)_sinittext,
|
|
(unsigned long)(_einittext - _sinittext) >> PAGE_SHIFT,
|
|
SET_MEMORY_RO | SET_MEMORY_X);
|
|
__set_memory(__stext_dma, (__etext_dma - __stext_dma) >> PAGE_SHIFT,
|
|
SET_MEMORY_RO | SET_MEMORY_X);
|
|
|
|
/* we need lowcore executable for our LPSWE instructions */
|
|
set_memory_x(0, 1);
|
|
|
|
pr_info("Write protected kernel read-only data: %luk\n",
|
|
(unsigned long)(__end_rodata - _stext) >> 10);
|
|
}
|