/* * Page table handling routines for radix page table. * * Copyright 2015-2016, Aneesh Kumar K.V, IBM Corporation. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #define pr_fmt(fmt) "radix-mmu: " fmt #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include unsigned int mmu_pid_bits; unsigned int mmu_base_pid; static int native_register_process_table(unsigned long base, unsigned long pg_sz, unsigned long table_size) { unsigned long patb0, patb1; patb0 = be64_to_cpu(partition_tb[0].patb0); patb1 = base | table_size | PATB_GR; mmu_partition_table_set_entry(0, patb0, patb1); return 0; } static __ref void *early_alloc_pgtable(unsigned long size) { void *pt; pt = __va(memblock_alloc_base(size, size, MEMBLOCK_ALLOC_ANYWHERE)); memset(pt, 0, size); return pt; } int radix__map_kernel_page(unsigned long ea, unsigned long pa, pgprot_t flags, unsigned int map_page_size) { pgd_t *pgdp; pud_t *pudp; pmd_t *pmdp; pte_t *ptep; /* * Make sure task size is correct as per the max adddr */ BUILD_BUG_ON(TASK_SIZE_USER64 > RADIX_PGTABLE_RANGE); if (slab_is_available()) { pgdp = pgd_offset_k(ea); pudp = pud_alloc(&init_mm, pgdp, ea); if (!pudp) return -ENOMEM; if (map_page_size == PUD_SIZE) { ptep = (pte_t *)pudp; goto set_the_pte; } pmdp = pmd_alloc(&init_mm, pudp, ea); if (!pmdp) return -ENOMEM; if (map_page_size == PMD_SIZE) { ptep = pmdp_ptep(pmdp); goto set_the_pte; } ptep = pte_alloc_kernel(pmdp, ea); if (!ptep) return -ENOMEM; } else { pgdp = pgd_offset_k(ea); if (pgd_none(*pgdp)) { pudp = early_alloc_pgtable(PUD_TABLE_SIZE); BUG_ON(pudp == NULL); pgd_populate(&init_mm, pgdp, pudp); } pudp = pud_offset(pgdp, ea); if (map_page_size == PUD_SIZE) { ptep = (pte_t *)pudp; goto set_the_pte; } if (pud_none(*pudp)) { pmdp = early_alloc_pgtable(PMD_TABLE_SIZE); BUG_ON(pmdp == NULL); pud_populate(&init_mm, pudp, pmdp); } pmdp = pmd_offset(pudp, ea); if (map_page_size == PMD_SIZE) { ptep = pmdp_ptep(pmdp); goto set_the_pte; } if (!pmd_present(*pmdp)) { ptep = early_alloc_pgtable(PAGE_SIZE); BUG_ON(ptep == NULL); pmd_populate_kernel(&init_mm, pmdp, ptep); } ptep = pte_offset_kernel(pmdp, ea); } set_the_pte: set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT, flags)); smp_wmb(); return 0; } #ifdef CONFIG_STRICT_KERNEL_RWX void radix__change_memory_range(unsigned long start, unsigned long end, unsigned long clear) { unsigned long idx; pgd_t *pgdp; pud_t *pudp; pmd_t *pmdp; pte_t *ptep; start = ALIGN_DOWN(start, PAGE_SIZE); end = PAGE_ALIGN(end); // aligns up pr_debug("Changing flags on range %lx-%lx removing 0x%lx\n", start, end, clear); for (idx = start; idx < end; idx += PAGE_SIZE) { pgdp = pgd_offset_k(idx); pudp = pud_alloc(&init_mm, pgdp, idx); if (!pudp) continue; if (pud_huge(*pudp)) { ptep = (pte_t *)pudp; goto update_the_pte; } pmdp = pmd_alloc(&init_mm, pudp, idx); if (!pmdp) continue; if (pmd_huge(*pmdp)) { ptep = pmdp_ptep(pmdp); goto update_the_pte; } ptep = pte_alloc_kernel(pmdp, idx); if (!ptep) continue; update_the_pte: radix__pte_update(&init_mm, idx, ptep, clear, 0, 0); } radix__flush_tlb_kernel_range(start, end); } void radix__mark_rodata_ro(void) { unsigned long start, end; /* * mark_rodata_ro() will mark itself as !writable at some point. * Due to DD1 workaround in radix__pte_update(), we'll end up with * an invalid pte and the system will crash quite severly. */ if (cpu_has_feature(CPU_FTR_POWER9_DD1)) { pr_warn("Warning: Unable to mark rodata read only on P9 DD1\n"); return; } start = (unsigned long)_stext; end = (unsigned long)__init_begin; radix__change_memory_range(start, end, _PAGE_WRITE); } void radix__mark_initmem_nx(void) { unsigned long start = (unsigned long)__init_begin; unsigned long end = (unsigned long)__init_end; radix__change_memory_range(start, end, _PAGE_EXEC); } #endif /* CONFIG_STRICT_KERNEL_RWX */ static inline void __meminit print_mapping(unsigned long start, unsigned long end, unsigned long size) { char buf[10]; if (end <= start) return; string_get_size(size, 1, STRING_UNITS_2, buf, sizeof(buf)); pr_info("Mapped 0x%016lx-0x%016lx with %s pages\n", start, end, buf); } static int __meminit create_physical_mapping(unsigned long start, unsigned long end) { unsigned long vaddr, addr, mapping_size = 0; pgprot_t prot; unsigned long max_mapping_size; #ifdef CONFIG_STRICT_KERNEL_RWX int split_text_mapping = 1; #else int split_text_mapping = 0; #endif start = _ALIGN_UP(start, PAGE_SIZE); for (addr = start; addr < end; addr += mapping_size) { unsigned long gap, previous_size; int rc; gap = end - addr; previous_size = mapping_size; max_mapping_size = PUD_SIZE; retry: if (IS_ALIGNED(addr, PUD_SIZE) && gap >= PUD_SIZE && mmu_psize_defs[MMU_PAGE_1G].shift && PUD_SIZE <= max_mapping_size) mapping_size = PUD_SIZE; else if (IS_ALIGNED(addr, PMD_SIZE) && gap >= PMD_SIZE && mmu_psize_defs[MMU_PAGE_2M].shift) mapping_size = PMD_SIZE; else mapping_size = PAGE_SIZE; if (split_text_mapping && (mapping_size == PUD_SIZE) && (addr <= __pa_symbol(__init_begin)) && (addr + mapping_size) >= __pa_symbol(_stext)) { max_mapping_size = PMD_SIZE; goto retry; } if (split_text_mapping && (mapping_size == PMD_SIZE) && (addr <= __pa_symbol(__init_begin)) && (addr + mapping_size) >= __pa_symbol(_stext)) mapping_size = PAGE_SIZE; if (mapping_size != previous_size) { print_mapping(start, addr, previous_size); start = addr; } vaddr = (unsigned long)__va(addr); if (overlaps_kernel_text(vaddr, vaddr + mapping_size) || overlaps_interrupt_vector_text(vaddr, vaddr + mapping_size)) prot = PAGE_KERNEL_X; else prot = PAGE_KERNEL; rc = radix__map_kernel_page(vaddr, addr, prot, mapping_size); if (rc) return rc; } print_mapping(start, addr, mapping_size); return 0; } static void __init radix_init_pgtable(void) { unsigned long rts_field; struct memblock_region *reg; /* We don't support slb for radix */ mmu_slb_size = 0; /* * Create the linear mapping, using standard page size for now */ for_each_memblock(memory, reg) WARN_ON(create_physical_mapping(reg->base, reg->base + reg->size)); /* Find out how many PID bits are supported */ if (cpu_has_feature(CPU_FTR_HVMODE)) { if (!mmu_pid_bits) mmu_pid_bits = 20; #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE /* * When KVM is possible, we only use the top half of the * PID space to avoid collisions between host and guest PIDs * which can cause problems due to prefetch when exiting the * guest with AIL=3 */ mmu_base_pid = 1 << (mmu_pid_bits - 1); #else mmu_base_pid = 1; #endif } else { /* The guest uses the bottom half of the PID space */ if (!mmu_pid_bits) mmu_pid_bits = 19; mmu_base_pid = 1; } /* * Allocate Partition table and process table for the * host. */ BUG_ON(PRTB_SIZE_SHIFT > 36); process_tb = early_alloc_pgtable(1UL << PRTB_SIZE_SHIFT); /* * Fill in the process table. */ rts_field = radix__get_tree_size(); process_tb->prtb0 = cpu_to_be64(rts_field | __pa(init_mm.pgd) | RADIX_PGD_INDEX_SIZE); /* * Fill in the partition table. We are suppose to use effective address * of process table here. But our linear mapping also enable us to use * physical address here. */ register_process_table(__pa(process_tb), 0, PRTB_SIZE_SHIFT - 12); pr_info("Process table %p and radix root for kernel: %p\n", process_tb, init_mm.pgd); asm volatile("ptesync" : : : "memory"); asm volatile(PPC_TLBIE_5(%0,%1,2,1,1) : : "r" (TLBIEL_INVAL_SET_LPID), "r" (0)); asm volatile("eieio; tlbsync; ptesync" : : : "memory"); trace_tlbie(0, 0, TLBIEL_INVAL_SET_LPID, 0, 2, 1, 1); } static void __init radix_init_partition_table(void) { unsigned long rts_field, dw0; mmu_partition_table_init(); rts_field = radix__get_tree_size(); dw0 = rts_field | __pa(init_mm.pgd) | RADIX_PGD_INDEX_SIZE | PATB_HR; mmu_partition_table_set_entry(0, dw0, 0); pr_info("Initializing Radix MMU\n"); pr_info("Partition table %p\n", partition_tb); } void __init radix_init_native(void) { register_process_table = native_register_process_table; } static int __init get_idx_from_shift(unsigned int shift) { int idx = -1; switch (shift) { case 0xc: idx = MMU_PAGE_4K; break; case 0x10: idx = MMU_PAGE_64K; break; case 0x15: idx = MMU_PAGE_2M; break; case 0x1e: idx = MMU_PAGE_1G; break; } return idx; } static int __init radix_dt_scan_page_sizes(unsigned long node, const char *uname, int depth, void *data) { int size = 0; int shift, idx; unsigned int ap; const __be32 *prop; const char *type = of_get_flat_dt_prop(node, "device_type", NULL); /* We are scanning "cpu" nodes only */ if (type == NULL || strcmp(type, "cpu") != 0) return 0; /* Find MMU PID size */ prop = of_get_flat_dt_prop(node, "ibm,mmu-pid-bits", &size); if (prop && size == 4) mmu_pid_bits = be32_to_cpup(prop); /* Grab page size encodings */ prop = of_get_flat_dt_prop(node, "ibm,processor-radix-AP-encodings", &size); if (!prop) return 0; pr_info("Page sizes from device-tree:\n"); for (; size >= 4; size -= 4, ++prop) { struct mmu_psize_def *def; /* top 3 bit is AP encoding */ shift = be32_to_cpu(prop[0]) & ~(0xe << 28); ap = be32_to_cpu(prop[0]) >> 29; pr_info("Page size shift = %d AP=0x%x\n", shift, ap); idx = get_idx_from_shift(shift); if (idx < 0) continue; def = &mmu_psize_defs[idx]; def->shift = shift; def->ap = ap; } /* needed ? */ cur_cpu_spec->mmu_features &= ~MMU_FTR_NO_SLBIE_B; return 1; } void __init radix__early_init_devtree(void) { int rc; /* * Try to find the available page sizes in the device-tree */ rc = of_scan_flat_dt(radix_dt_scan_page_sizes, NULL); if (rc != 0) /* Found */ goto found; /* * let's assume we have page 4k and 64k support */ mmu_psize_defs[MMU_PAGE_4K].shift = 12; mmu_psize_defs[MMU_PAGE_4K].ap = 0x0; mmu_psize_defs[MMU_PAGE_64K].shift = 16; mmu_psize_defs[MMU_PAGE_64K].ap = 0x5; found: #ifdef CONFIG_SPARSEMEM_VMEMMAP if (mmu_psize_defs[MMU_PAGE_2M].shift) { /* * map vmemmap using 2M if available */ mmu_vmemmap_psize = MMU_PAGE_2M; } #endif /* CONFIG_SPARSEMEM_VMEMMAP */ return; } static void update_hid_for_radix(void) { unsigned long hid0; unsigned long rb = 3UL << PPC_BITLSHIFT(53); /* IS = 3 */ asm volatile("ptesync": : :"memory"); /* prs = 0, ric = 2, rs = 0, r = 1 is = 3 */ asm volatile(PPC_TLBIE_5(%0, %4, %3, %2, %1) : : "r"(rb), "i"(1), "i"(0), "i"(2), "r"(0) : "memory"); /* prs = 1, ric = 2, rs = 0, r = 1 is = 3 */ asm volatile(PPC_TLBIE_5(%0, %4, %3, %2, %1) : : "r"(rb), "i"(1), "i"(1), "i"(2), "r"(0) : "memory"); asm volatile("eieio; tlbsync; ptesync; isync; slbia": : :"memory"); trace_tlbie(0, 0, rb, 0, 2, 0, 1); trace_tlbie(0, 0, rb, 0, 2, 1, 1); /* * now switch the HID */ hid0 = mfspr(SPRN_HID0); hid0 |= HID0_POWER9_RADIX; mtspr(SPRN_HID0, hid0); asm volatile("isync": : :"memory"); /* Wait for it to happen */ while (!(mfspr(SPRN_HID0) & HID0_POWER9_RADIX)) cpu_relax(); } static void radix_init_amor(void) { /* * In HV mode, we init AMOR (Authority Mask Override Register) so that * the hypervisor and guest can setup IAMR (Instruction Authority Mask * Register), enable key 0 and set it to 1. * * AMOR = 0b1100 .... 0000 (Mask for key 0 is 11) */ mtspr(SPRN_AMOR, (3ul << 62)); } static void radix_init_iamr(void) { unsigned long iamr; /* * The IAMR should set to 0 on DD1. */ if (cpu_has_feature(CPU_FTR_POWER9_DD1)) iamr = 0; else iamr = (1ul << 62); /* * Radix always uses key0 of the IAMR to determine if an access is * allowed. We set bit 0 (IBM bit 1) of key0, to prevent instruction * fetch. */ mtspr(SPRN_IAMR, iamr); } void __init radix__early_init_mmu(void) { unsigned long lpcr; #ifdef CONFIG_PPC_64K_PAGES /* PAGE_SIZE mappings */ mmu_virtual_psize = MMU_PAGE_64K; #else mmu_virtual_psize = MMU_PAGE_4K; #endif #ifdef CONFIG_SPARSEMEM_VMEMMAP /* vmemmap mapping */ mmu_vmemmap_psize = mmu_virtual_psize; #endif /* * initialize page table size */ __pte_index_size = RADIX_PTE_INDEX_SIZE; __pmd_index_size = RADIX_PMD_INDEX_SIZE; __pud_index_size = RADIX_PUD_INDEX_SIZE; __pgd_index_size = RADIX_PGD_INDEX_SIZE; __pmd_cache_index = RADIX_PMD_INDEX_SIZE; __pte_table_size = RADIX_PTE_TABLE_SIZE; __pmd_table_size = RADIX_PMD_TABLE_SIZE; __pud_table_size = RADIX_PUD_TABLE_SIZE; __pgd_table_size = RADIX_PGD_TABLE_SIZE; __pmd_val_bits = RADIX_PMD_VAL_BITS; __pud_val_bits = RADIX_PUD_VAL_BITS; __pgd_val_bits = RADIX_PGD_VAL_BITS; __kernel_virt_start = RADIX_KERN_VIRT_START; __kernel_virt_size = RADIX_KERN_VIRT_SIZE; __vmalloc_start = RADIX_VMALLOC_START; __vmalloc_end = RADIX_VMALLOC_END; __kernel_io_start = RADIX_KERN_IO_START; vmemmap = (struct page *)RADIX_VMEMMAP_BASE; ioremap_bot = IOREMAP_BASE; #ifdef CONFIG_PCI pci_io_base = ISA_IO_BASE; #endif /* * For now radix also use the same frag size */ __pte_frag_nr = H_PTE_FRAG_NR; __pte_frag_size_shift = H_PTE_FRAG_SIZE_SHIFT; if (!firmware_has_feature(FW_FEATURE_LPAR)) { radix_init_native(); if (cpu_has_feature(CPU_FTR_POWER9_DD1)) update_hid_for_radix(); lpcr = mfspr(SPRN_LPCR); mtspr(SPRN_LPCR, lpcr | LPCR_UPRT | LPCR_HR); radix_init_partition_table(); radix_init_amor(); } else { radix_init_pseries(); } memblock_set_current_limit(MEMBLOCK_ALLOC_ANYWHERE); radix_init_iamr(); radix_init_pgtable(); } void radix__early_init_mmu_secondary(void) { unsigned long lpcr; /* * update partition table control register and UPRT */ if (!firmware_has_feature(FW_FEATURE_LPAR)) { if (cpu_has_feature(CPU_FTR_POWER9_DD1)) update_hid_for_radix(); lpcr = mfspr(SPRN_LPCR); mtspr(SPRN_LPCR, lpcr | LPCR_UPRT | LPCR_HR); mtspr(SPRN_PTCR, __pa(partition_tb) | (PATB_SIZE_SHIFT - 12)); radix_init_amor(); } radix_init_iamr(); } void radix__mmu_cleanup_all(void) { unsigned long lpcr; if (!firmware_has_feature(FW_FEATURE_LPAR)) { lpcr = mfspr(SPRN_LPCR); mtspr(SPRN_LPCR, lpcr & ~LPCR_UPRT); mtspr(SPRN_PTCR, 0); powernv_set_nmmu_ptcr(0); radix__flush_tlb_all(); } } void radix__setup_initial_memory_limit(phys_addr_t first_memblock_base, phys_addr_t first_memblock_size) { /* We don't currently support the first MEMBLOCK not mapping 0 * physical on those processors */ BUG_ON(first_memblock_base != 0); /* * We limit the allocation that depend on ppc64_rma_size * to first_memblock_size. We also clamp it to 1GB to * avoid some funky things such as RTAS bugs. * * On radix config we really don't have a limitation * on real mode access. But keeping it as above works * well enough. */ ppc64_rma_size = min_t(u64, first_memblock_size, 0x40000000); /* * Finally limit subsequent allocations. We really don't want * to limit the memblock allocations to rma_size. FIXME!! should * we even limit at all ? */ memblock_set_current_limit(first_memblock_base + first_memblock_size); } #ifdef CONFIG_MEMORY_HOTPLUG static void free_pte_table(pte_t *pte_start, pmd_t *pmd) { pte_t *pte; int i; for (i = 0; i < PTRS_PER_PTE; i++) { pte = pte_start + i; if (!pte_none(*pte)) return; } pte_free_kernel(&init_mm, pte_start); pmd_clear(pmd); } static void free_pmd_table(pmd_t *pmd_start, pud_t *pud) { pmd_t *pmd; int i; for (i = 0; i < PTRS_PER_PMD; i++) { pmd = pmd_start + i; if (!pmd_none(*pmd)) return; } pmd_free(&init_mm, pmd_start); pud_clear(pud); } static void remove_pte_table(pte_t *pte_start, unsigned long addr, unsigned long end) { unsigned long next; pte_t *pte; pte = pte_start + pte_index(addr); for (; addr < end; addr = next, pte++) { next = (addr + PAGE_SIZE) & PAGE_MASK; if (next > end) next = end; if (!pte_present(*pte)) continue; if (!PAGE_ALIGNED(addr) || !PAGE_ALIGNED(next)) { /* * The vmemmap_free() and remove_section_mapping() * codepaths call us with aligned addresses. */ WARN_ONCE(1, "%s: unaligned range\n", __func__); continue; } pte_clear(&init_mm, addr, pte); } } static void remove_pmd_table(pmd_t *pmd_start, unsigned long addr, unsigned long end) { unsigned long next; pte_t *pte_base; pmd_t *pmd; pmd = pmd_start + pmd_index(addr); for (; addr < end; addr = next, pmd++) { next = pmd_addr_end(addr, end); if (!pmd_present(*pmd)) continue; if (pmd_huge(*pmd)) { if (!IS_ALIGNED(addr, PMD_SIZE) || !IS_ALIGNED(next, PMD_SIZE)) { WARN_ONCE(1, "%s: unaligned range\n", __func__); continue; } pte_clear(&init_mm, addr, (pte_t *)pmd); continue; } pte_base = (pte_t *)pmd_page_vaddr(*pmd); remove_pte_table(pte_base, addr, next); free_pte_table(pte_base, pmd); } } static void remove_pud_table(pud_t *pud_start, unsigned long addr, unsigned long end) { unsigned long next; pmd_t *pmd_base; pud_t *pud; pud = pud_start + pud_index(addr); for (; addr < end; addr = next, pud++) { next = pud_addr_end(addr, end); if (!pud_present(*pud)) continue; if (pud_huge(*pud)) { if (!IS_ALIGNED(addr, PUD_SIZE) || !IS_ALIGNED(next, PUD_SIZE)) { WARN_ONCE(1, "%s: unaligned range\n", __func__); continue; } pte_clear(&init_mm, addr, (pte_t *)pud); continue; } pmd_base = (pmd_t *)pud_page_vaddr(*pud); remove_pmd_table(pmd_base, addr, next); free_pmd_table(pmd_base, pud); } } static void remove_pagetable(unsigned long start, unsigned long end) { unsigned long addr, next; pud_t *pud_base; pgd_t *pgd; spin_lock(&init_mm.page_table_lock); for (addr = start; addr < end; addr = next) { next = pgd_addr_end(addr, end); pgd = pgd_offset_k(addr); if (!pgd_present(*pgd)) continue; if (pgd_huge(*pgd)) { if (!IS_ALIGNED(addr, PGDIR_SIZE) || !IS_ALIGNED(next, PGDIR_SIZE)) { WARN_ONCE(1, "%s: unaligned range\n", __func__); continue; } pte_clear(&init_mm, addr, (pte_t *)pgd); continue; } pud_base = (pud_t *)pgd_page_vaddr(*pgd); remove_pud_table(pud_base, addr, next); } spin_unlock(&init_mm.page_table_lock); radix__flush_tlb_kernel_range(start, end); } int __ref radix__create_section_mapping(unsigned long start, unsigned long end) { return create_physical_mapping(start, end); } int radix__remove_section_mapping(unsigned long start, unsigned long end) { remove_pagetable(start, end); return 0; } #endif /* CONFIG_MEMORY_HOTPLUG */ #ifdef CONFIG_SPARSEMEM_VMEMMAP int __meminit radix__vmemmap_create_mapping(unsigned long start, unsigned long page_size, unsigned long phys) { /* Create a PTE encoding */ unsigned long flags = _PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_KERNEL_RW; BUG_ON(radix__map_kernel_page(start, phys, __pgprot(flags), page_size)); return 0; } #ifdef CONFIG_MEMORY_HOTPLUG void radix__vmemmap_remove_mapping(unsigned long start, unsigned long page_size) { remove_pagetable(start, start + page_size); } #endif #endif #ifdef CONFIG_TRANSPARENT_HUGEPAGE unsigned long radix__pmd_hugepage_update(struct mm_struct *mm, unsigned long addr, pmd_t *pmdp, unsigned long clr, unsigned long set) { unsigned long old; #ifdef CONFIG_DEBUG_VM WARN_ON(!radix__pmd_trans_huge(*pmdp) && !pmd_devmap(*pmdp)); assert_spin_locked(&mm->page_table_lock); #endif old = radix__pte_update(mm, addr, (pte_t *)pmdp, clr, set, 1); trace_hugepage_update(addr, old, clr, set); return old; } pmd_t radix__pmdp_collapse_flush(struct vm_area_struct *vma, unsigned long address, pmd_t *pmdp) { pmd_t pmd; VM_BUG_ON(address & ~HPAGE_PMD_MASK); VM_BUG_ON(radix__pmd_trans_huge(*pmdp)); VM_BUG_ON(pmd_devmap(*pmdp)); /* * khugepaged calls this for normal pmd */ pmd = *pmdp; pmd_clear(pmdp); /*FIXME!! Verify whether we need this kick below */ serialize_against_pte_lookup(vma->vm_mm); radix__flush_tlb_collapsed_pmd(vma->vm_mm, address); return pmd; } /* * For us pgtable_t is pte_t *. Inorder to save the deposisted * page table, we consider the allocated page table as a list * head. On withdraw we need to make sure we zero out the used * list_head memory area. */ void radix__pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp, pgtable_t pgtable) { struct list_head *lh = (struct list_head *) pgtable; assert_spin_locked(pmd_lockptr(mm, pmdp)); /* FIFO */ if (!pmd_huge_pte(mm, pmdp)) INIT_LIST_HEAD(lh); else list_add(lh, (struct list_head *) pmd_huge_pte(mm, pmdp)); pmd_huge_pte(mm, pmdp) = pgtable; } pgtable_t radix__pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp) { pte_t *ptep; pgtable_t pgtable; struct list_head *lh; assert_spin_locked(pmd_lockptr(mm, pmdp)); /* FIFO */ pgtable = pmd_huge_pte(mm, pmdp); lh = (struct list_head *) pgtable; if (list_empty(lh)) pmd_huge_pte(mm, pmdp) = NULL; else { pmd_huge_pte(mm, pmdp) = (pgtable_t) lh->next; list_del(lh); } ptep = (pte_t *) pgtable; *ptep = __pte(0); ptep++; *ptep = __pte(0); return pgtable; } pmd_t radix__pmdp_huge_get_and_clear(struct mm_struct *mm, unsigned long addr, pmd_t *pmdp) { pmd_t old_pmd; unsigned long old; old = radix__pmd_hugepage_update(mm, addr, pmdp, ~0UL, 0); old_pmd = __pmd(old); /* * Serialize against find_current_mm_pte which does lock-less * lookup in page tables with local interrupts disabled. For huge pages * it casts pmd_t to pte_t. Since format of pte_t is different from * pmd_t we want to prevent transit from pmd pointing to page table * to pmd pointing to huge page (and back) while interrupts are disabled. * We clear pmd to possibly replace it with page table pointer in * different code paths. So make sure we wait for the parallel * find_current_mm_pte to finish. */ serialize_against_pte_lookup(mm); return old_pmd; } int radix__has_transparent_hugepage(void) { /* For radix 2M at PMD level means thp */ if (mmu_psize_defs[MMU_PAGE_2M].shift == PMD_SHIFT) return 1; return 0; } #endif /* CONFIG_TRANSPARENT_HUGEPAGE */