11f9ad21cSRussell Currey // SPDX-License-Identifier: GPL-2.0
21f9ad21cSRussell Currey
31f9ad21cSRussell Currey /*
41f9ad21cSRussell Currey * MMU-generic set_memory implementation for powerpc
51f9ad21cSRussell Currey *
61f9ad21cSRussell Currey * Copyright 2019-2021, IBM Corporation.
71f9ad21cSRussell Currey */
81f9ad21cSRussell Currey
91f9ad21cSRussell Currey #include <linux/mm.h>
101f9ad21cSRussell Currey #include <linux/vmalloc.h>
111f9ad21cSRussell Currey #include <linux/set_memory.h>
121f9ad21cSRussell Currey
131f9ad21cSRussell Currey #include <asm/mmu.h>
141f9ad21cSRussell Currey #include <asm/page.h>
151f9ad21cSRussell Currey #include <asm/pgtable.h>
161f9ad21cSRussell Currey
171f9ad21cSRussell Currey
pte_update_delta(pte_t * ptep,unsigned long addr,unsigned long old,unsigned long new)18a4c182ecSChristophe Leroy static pte_basic_t pte_update_delta(pte_t *ptep, unsigned long addr,
19a4c182ecSChristophe Leroy unsigned long old, unsigned long new)
20a4c182ecSChristophe Leroy {
21a4c182ecSChristophe Leroy return pte_update(&init_mm, addr, ptep, old & ~new, new & ~old, 0);
22a4c182ecSChristophe Leroy }
23a4c182ecSChristophe Leroy
241f9ad21cSRussell Currey /*
25a4c182ecSChristophe Leroy * Updates the attributes of a page atomically.
261f9ad21cSRussell Currey *
279f7853d7SMichael Ellerman * This sequence is safe against concurrent updates, and also allows updating the
289f7853d7SMichael Ellerman * attributes of a page currently being executed or accessed.
291f9ad21cSRussell Currey */
change_page_attr(pte_t * ptep,unsigned long addr,void * data)301f9ad21cSRussell Currey static int change_page_attr(pte_t *ptep, unsigned long addr, void *data)
311f9ad21cSRussell Currey {
321f9ad21cSRussell Currey long action = (long)data;
331f9ad21cSRussell Currey
34*65883b78SChristophe Leroy addr &= PAGE_MASK;
35a4c182ecSChristophe Leroy /* modify the PTE bits as desired */
361f9ad21cSRussell Currey switch (action) {
371f9ad21cSRussell Currey case SET_MEMORY_RO:
38a4c182ecSChristophe Leroy /* Don't clear DIRTY bit */
39a4c182ecSChristophe Leroy pte_update_delta(ptep, addr, _PAGE_KERNEL_RW & ~_PAGE_DIRTY, _PAGE_KERNEL_RO);
401f9ad21cSRussell Currey break;
411f9ad21cSRussell Currey case SET_MEMORY_RW:
42a4c182ecSChristophe Leroy pte_update_delta(ptep, addr, _PAGE_KERNEL_RO, _PAGE_KERNEL_RW);
431f9ad21cSRussell Currey break;
441f9ad21cSRussell Currey case SET_MEMORY_NX:
45a4c182ecSChristophe Leroy pte_update_delta(ptep, addr, _PAGE_KERNEL_ROX, _PAGE_KERNEL_RO);
461f9ad21cSRussell Currey break;
471f9ad21cSRussell Currey case SET_MEMORY_X:
48a4c182ecSChristophe Leroy pte_update_delta(ptep, addr, _PAGE_KERNEL_RO, _PAGE_KERNEL_ROX);
491f9ad21cSRussell Currey break;
50f222ab83SChristophe Leroy case SET_MEMORY_NP:
51f222ab83SChristophe Leroy pte_update(&init_mm, addr, ptep, _PAGE_PRESENT, 0, 0);
52f222ab83SChristophe Leroy break;
53f222ab83SChristophe Leroy case SET_MEMORY_P:
54f222ab83SChristophe Leroy pte_update(&init_mm, addr, ptep, 0, _PAGE_PRESENT, 0);
55f222ab83SChristophe Leroy break;
561f9ad21cSRussell Currey default:
571f9ad21cSRussell Currey WARN_ON_ONCE(1);
581f9ad21cSRussell Currey break;
591f9ad21cSRussell Currey }
601f9ad21cSRussell Currey
611f9ad21cSRussell Currey /* See ptesync comment in radix__set_pte_at() */
621f9ad21cSRussell Currey if (radix_enabled())
631f9ad21cSRussell Currey asm volatile("ptesync": : :"memory");
649f7853d7SMichael Ellerman
659f7853d7SMichael Ellerman flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
669f7853d7SMichael Ellerman
671f9ad21cSRussell Currey return 0;
681f9ad21cSRussell Currey }
691f9ad21cSRussell Currey
change_memory_attr(unsigned long addr,int numpages,long action)701f9ad21cSRussell Currey int change_memory_attr(unsigned long addr, int numpages, long action)
711f9ad21cSRussell Currey {
721f9ad21cSRussell Currey unsigned long start = ALIGN_DOWN(addr, PAGE_SIZE);
731f9ad21cSRussell Currey unsigned long size = numpages * PAGE_SIZE;
741f9ad21cSRussell Currey
751f9ad21cSRussell Currey if (!numpages)
761f9ad21cSRussell Currey return 0;
771f9ad21cSRussell Currey
781f9ad21cSRussell Currey if (WARN_ON_ONCE(is_vmalloc_or_module_addr((void *)addr) &&
791f9ad21cSRussell Currey is_vm_area_hugepages((void *)addr)))
801f9ad21cSRussell Currey return -EINVAL;
811f9ad21cSRussell Currey
821f9ad21cSRussell Currey #ifdef CONFIG_PPC_BOOK3S_64
831f9ad21cSRussell Currey /*
841f9ad21cSRussell Currey * On hash, the linear mapping is not in the Linux page table so
851f9ad21cSRussell Currey * apply_to_existing_page_range() will have no effect. If in the future
861f9ad21cSRussell Currey * the set_memory_* functions are used on the linear map this will need
871f9ad21cSRussell Currey * to be updated.
881f9ad21cSRussell Currey */
891f9ad21cSRussell Currey if (!radix_enabled()) {
901f9ad21cSRussell Currey int region = get_region_id(addr);
911f9ad21cSRussell Currey
921f9ad21cSRussell Currey if (WARN_ON_ONCE(region != VMALLOC_REGION_ID && region != IO_REGION_ID))
931f9ad21cSRussell Currey return -EINVAL;
941f9ad21cSRussell Currey }
951f9ad21cSRussell Currey #endif
961f9ad21cSRussell Currey
971f9ad21cSRussell Currey return apply_to_existing_page_range(&init_mm, start, size,
981f9ad21cSRussell Currey change_page_attr, (void *)action);
991f9ad21cSRussell Currey }
100