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98 lines
2.5 KiB
98 lines
2.5 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* MMU-generic set_memory implementation for powerpc |
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* |
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* Copyright 2019-2021, IBM Corporation. |
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*/ |
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#include <linux/mm.h> |
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#include <linux/vmalloc.h> |
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#include <linux/set_memory.h> |
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#include <asm/mmu.h> |
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#include <asm/page.h> |
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#include <asm/pgtable.h> |
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static pte_basic_t pte_update_delta(pte_t *ptep, unsigned long addr, |
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unsigned long old, unsigned long new) |
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{ |
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return pte_update(&init_mm, addr, ptep, old & ~new, new & ~old, 0); |
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} |
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/* |
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* Updates the attributes of a page atomically. |
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* |
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* This sequence is safe against concurrent updates, and also allows updating the |
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* attributes of a page currently being executed or accessed. |
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*/ |
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static int change_page_attr(pte_t *ptep, unsigned long addr, void *data) |
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{ |
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long action = (long)data; |
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/* modify the PTE bits as desired */ |
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switch (action) { |
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case SET_MEMORY_RO: |
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/* Don't clear DIRTY bit */ |
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pte_update_delta(ptep, addr, _PAGE_KERNEL_RW & ~_PAGE_DIRTY, _PAGE_KERNEL_RO); |
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break; |
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case SET_MEMORY_RW: |
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pte_update_delta(ptep, addr, _PAGE_KERNEL_RO, _PAGE_KERNEL_RW); |
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break; |
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case SET_MEMORY_NX: |
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pte_update_delta(ptep, addr, _PAGE_KERNEL_ROX, _PAGE_KERNEL_RO); |
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break; |
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case SET_MEMORY_X: |
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pte_update_delta(ptep, addr, _PAGE_KERNEL_RO, _PAGE_KERNEL_ROX); |
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break; |
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case SET_MEMORY_NP: |
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pte_update(&init_mm, addr, ptep, _PAGE_PRESENT, 0, 0); |
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break; |
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case SET_MEMORY_P: |
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pte_update(&init_mm, addr, ptep, 0, _PAGE_PRESENT, 0); |
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break; |
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default: |
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WARN_ON_ONCE(1); |
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break; |
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} |
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/* See ptesync comment in radix__set_pte_at() */ |
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if (radix_enabled()) |
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asm volatile("ptesync": : :"memory"); |
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flush_tlb_kernel_range(addr, addr + PAGE_SIZE); |
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return 0; |
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} |
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int change_memory_attr(unsigned long addr, int numpages, long action) |
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{ |
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unsigned long start = ALIGN_DOWN(addr, PAGE_SIZE); |
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unsigned long size = numpages * PAGE_SIZE; |
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if (!numpages) |
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return 0; |
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if (WARN_ON_ONCE(is_vmalloc_or_module_addr((void *)addr) && |
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is_vm_area_hugepages((void *)addr))) |
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return -EINVAL; |
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#ifdef CONFIG_PPC_BOOK3S_64 |
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/* |
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* On hash, the linear mapping is not in the Linux page table so |
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* apply_to_existing_page_range() will have no effect. If in the future |
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* the set_memory_* functions are used on the linear map this will need |
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* to be updated. |
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*/ |
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if (!radix_enabled()) { |
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int region = get_region_id(addr); |
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if (WARN_ON_ONCE(region != VMALLOC_REGION_ID && region != IO_REGION_ID)) |
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return -EINVAL; |
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} |
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#endif |
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return apply_to_existing_page_range(&init_mm, start, size, |
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change_page_attr, (void *)action); |
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}
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