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592 lines
14 KiB
592 lines
14 KiB
// 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 <[email protected]> |
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*/ |
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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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|
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static DEFINE_MUTEX(vmem_mutex); |
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|
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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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|
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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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|
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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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|
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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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|
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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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/* |
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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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/* |
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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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/* |
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* Add a backed mem_map array to the virtual mem_map array. |
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*/ |
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int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, |
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struct vmem_altmap *altmap) |
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{ |
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int ret; |
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|
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mutex_lock(&vmem_mutex); |
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/* We don't care about the node, just use NUMA_NO_NODE on allocations */ |
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ret = add_pagetable(start, end, false); |
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if (ret) |
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remove_pagetable(start, end, false); |
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mutex_unlock(&vmem_mutex); |
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return ret; |
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} |
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|
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void vmemmap_free(unsigned long start, unsigned long end, |
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struct vmem_altmap *altmap) |
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{ |
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mutex_lock(&vmem_mutex); |
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remove_pagetable(start, end, false); |
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mutex_unlock(&vmem_mutex); |
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} |
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|
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void vmem_remove_mapping(unsigned long start, unsigned long size) |
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{ |
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mutex_lock(&vmem_mutex); |
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vmem_remove_range(start, size); |
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mutex_unlock(&vmem_mutex); |
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} |
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struct range arch_get_mappable_range(void) |
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{ |
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struct range mhp_range; |
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|
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mhp_range.start = 0; |
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mhp_range.end = VMEM_MAX_PHYS - 1; |
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return mhp_range; |
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} |
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|
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int vmem_add_mapping(unsigned long start, unsigned long size) |
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{ |
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struct range range = arch_get_mappable_range(); |
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int ret; |
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|
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if (start < range.start || |
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start + size > range.end + 1 || |
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start + size < start) |
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return -ERANGE; |
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mutex_lock(&vmem_mutex); |
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ret = vmem_add_range(start, size); |
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if (ret) |
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vmem_remove_range(start, size); |
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mutex_unlock(&vmem_mutex); |
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return ret; |
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} |
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|
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/* |
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* map whole physical memory to virtual memory (identity mapping) |
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* we reserve enough space in the vmalloc area for vmemmap to hotplug |
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* additional memory segments. |
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*/ |
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void __init vmem_map_init(void) |
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{ |
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phys_addr_t base, end; |
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u64 i; |
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|
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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); |
|
}
|
|
|