diff options
Diffstat (limited to 'arch/powerpc/mm/book3s64/radix_pgtable.c')
| -rw-r--r-- | arch/powerpc/mm/book3s64/radix_pgtable.c | 1124 |
1 files changed, 1124 insertions, 0 deletions
diff --git a/arch/powerpc/mm/book3s64/radix_pgtable.c b/arch/powerpc/mm/book3s64/radix_pgtable.c new file mode 100644 index 000000000000..c9bcf428dd2b --- /dev/null +++ b/arch/powerpc/mm/book3s64/radix_pgtable.c @@ -0,0 +1,1124 @@ +/* + * 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 <linux/kernel.h> +#include <linux/sched/mm.h> +#include <linux/memblock.h> +#include <linux/of_fdt.h> +#include <linux/mm.h> +#include <linux/string_helpers.h> +#include <linux/stop_machine.h> + +#include <asm/pgtable.h> +#include <asm/pgalloc.h> +#include <asm/mmu_context.h> +#include <asm/dma.h> +#include <asm/machdep.h> +#include <asm/mmu.h> +#include <asm/firmware.h> +#include <asm/powernv.h> +#include <asm/sections.h> +#include <asm/trace.h> +#include <asm/uaccess.h> + +#include <trace/events/thp.h> + +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, int nid, + unsigned long region_start, unsigned long region_end) +{ + phys_addr_t min_addr = MEMBLOCK_LOW_LIMIT; + phys_addr_t max_addr = MEMBLOCK_ALLOC_ANYWHERE; + void *ptr; + + if (region_start) + min_addr = region_start; + if (region_end) + max_addr = region_end; + + ptr = memblock_alloc_try_nid(size, size, min_addr, max_addr, nid); + + if (!ptr) + panic("%s: Failed to allocate %lu bytes align=0x%lx nid=%d from=%pa max_addr=%pa\n", + __func__, size, size, nid, &min_addr, &max_addr); + + return ptr; +} + +static int early_map_kernel_page(unsigned long ea, unsigned long pa, + pgprot_t flags, + unsigned int map_page_size, + int nid, + unsigned long region_start, unsigned long region_end) +{ + unsigned long pfn = pa >> PAGE_SHIFT; + pgd_t *pgdp; + pud_t *pudp; + pmd_t *pmdp; + pte_t *ptep; + + pgdp = pgd_offset_k(ea); + if (pgd_none(*pgdp)) { + pudp = early_alloc_pgtable(PUD_TABLE_SIZE, nid, + region_start, region_end); + 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, nid, + region_start, region_end); + 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, nid, + region_start, region_end); + 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(pfn, flags)); + smp_wmb(); + return 0; +} + +/* + * nid, region_start, and region_end are hints to try to place the page + * table memory in the same node or region. + */ +static int __map_kernel_page(unsigned long ea, unsigned long pa, + pgprot_t flags, + unsigned int map_page_size, + int nid, + unsigned long region_start, unsigned long region_end) +{ + unsigned long pfn = pa >> PAGE_SHIFT; + 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); + +#ifdef CONFIG_PPC_64K_PAGES + BUILD_BUG_ON(RADIX_KERN_MAP_SIZE != (1UL << MAX_EA_BITS_PER_CONTEXT)); +#endif + + if (unlikely(!slab_is_available())) + return early_map_kernel_page(ea, pa, flags, map_page_size, + nid, region_start, region_end); + + /* + * Should make page table allocation functions be able to take a + * node, so we can place kernel page tables on the right nodes after + * boot. + */ + 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; + +set_the_pte: + set_pte_at(&init_mm, ea, ptep, pfn_pte(pfn, flags)); + smp_wmb(); + return 0; +} + +int radix__map_kernel_page(unsigned long ea, unsigned long pa, + pgprot_t flags, + unsigned int map_page_size) +{ + return __map_kernel_page(ea, pa, flags, map_page_size, -1, 0, 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; + + 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, bool exec) +{ + 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%s\n", start, end, buf, + exec ? " (exec)" : ""); +} + +static unsigned long next_boundary(unsigned long addr, unsigned long end) +{ +#ifdef CONFIG_STRICT_KERNEL_RWX + if (addr < __pa_symbol(__init_begin)) + return __pa_symbol(__init_begin); +#endif + return end; +} + +static int __meminit create_physical_mapping(unsigned long start, + unsigned long end, + int nid) +{ + unsigned long vaddr, addr, mapping_size = 0; + bool prev_exec, exec = false; + pgprot_t prot; + int psize; + + start = _ALIGN_UP(start, PAGE_SIZE); + for (addr = start; addr < end; addr += mapping_size) { + unsigned long gap, previous_size; + int rc; + + gap = next_boundary(addr, end) - addr; + previous_size = mapping_size; + prev_exec = exec; + + if (IS_ALIGNED(addr, PUD_SIZE) && gap >= PUD_SIZE && + mmu_psize_defs[MMU_PAGE_1G].shift) { + mapping_size = PUD_SIZE; + psize = MMU_PAGE_1G; + } else if (IS_ALIGNED(addr, PMD_SIZE) && gap >= PMD_SIZE && + mmu_psize_defs[MMU_PAGE_2M].shift) { + mapping_size = PMD_SIZE; + psize = MMU_PAGE_2M; + } else { + mapping_size = PAGE_SIZE; + psize = mmu_virtual_psize; + } + + 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; + exec = true; + } else { + prot = PAGE_KERNEL; + exec = false; + } + + if (mapping_size != previous_size || exec != prev_exec) { + print_mapping(start, addr, previous_size, prev_exec); + start = addr; + } + + rc = __map_kernel_page(vaddr, addr, prot, mapping_size, nid, start, end); + if (rc) + return rc; + + update_page_count(psize, 1); + } + + print_mapping(start, addr, mapping_size, exec); + return 0; +} + +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) { + /* + * The memblock allocator is up at this point, so the + * page tables will be allocated within the range. No + * need or a node (which we don't have yet). + */ + + if ((reg->base + reg->size) >= RADIX_VMALLOC_START) { + pr_warn("Outside the supported range\n"); + continue; + } + + WARN_ON(create_physical_mapping(reg->base, + reg->base + reg->size, + -1)); + } + + /* 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, -1, 0, 0); + /* + * 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); + + /* + * The init_mm context is given the first available (non-zero) PID, + * which is the "guard PID" and contains no page table. PIDR should + * never be set to zero because that duplicates the kernel address + * space at the 0x0... offset (quadrant 0)! + * + * An arbitrary PID that may later be allocated by the PID allocator + * for userspace processes must not be used either, because that + * would cause stale user mappings for that PID on CPUs outside of + * the TLB invalidation scheme (because it won't be in mm_cpumask). + * + * So permanently carve out one PID for the purpose of a guard PID. + */ + init_mm.context.id = mmu_base_pid; + mmu_base_pid++; +} + +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 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)); +} + +#ifdef CONFIG_PPC_KUEP +void setup_kuep(bool disabled) +{ + if (disabled || !early_radix_enabled()) + return; + + if (smp_processor_id() == boot_cpuid) + pr_info("Activating Kernel Userspace Execution Prevention\n"); + + /* + * 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, (1ul << 62)); +} +#endif + +#ifdef CONFIG_PPC_KUAP +void setup_kuap(bool disabled) +{ + if (disabled || !early_radix_enabled()) + return; + + if (smp_processor_id() == boot_cpuid) { + pr_info("Activating Kernel Userspace Access Prevention\n"); + cur_cpu_spec->mmu_features |= MMU_FTR_RADIX_KUAP; + } + + /* Make sure userspace can't change the AMR */ + mtspr(SPRN_UAMOR, 0); + mtspr(SPRN_AMR, AMR_KUAP_BLOCKED); + isync(); +} +#endif + +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; + __pud_cache_index = RADIX_PUD_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; + __vmalloc_start = RADIX_VMALLOC_START; + __vmalloc_end = RADIX_VMALLOC_END; + __kernel_io_start = RADIX_KERN_IO_START; + __kernel_io_end = RADIX_KERN_IO_END; + vmemmap = (struct page *)RADIX_VMEMMAP_START; + ioremap_bot = IOREMAP_BASE; + +#ifdef CONFIG_PCI + pci_io_base = ISA_IO_BASE; +#endif + __pte_frag_nr = RADIX_PTE_FRAG_NR; + __pte_frag_size_shift = RADIX_PTE_FRAG_SIZE_SHIFT; + __pmd_frag_nr = RADIX_PMD_FRAG_NR; + __pmd_frag_size_shift = RADIX_PMD_FRAG_SIZE_SHIFT; + + if (!firmware_has_feature(FW_FEATURE_LPAR)) { + radix_init_native(); + 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_pgtable(); + /* Switch to the guard PID before turning on MMU */ + radix__switch_mmu_context(NULL, &init_mm); + if (cpu_has_feature(CPU_FTR_HVMODE)) + tlbiel_all(); +} + +void radix__early_init_mmu_secondary(void) +{ + unsigned long lpcr; + /* + * update partition table control register and UPRT + */ + if (!firmware_has_feature(FW_FEATURE_LPAR)) { + 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__switch_mmu_context(NULL, &init_mm); + if (cpu_has_feature(CPU_FTR_HVMODE)) + tlbiel_all(); +} + +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); + + /* + * Radix mode is not limited by RMA / VRMA addressing. + */ + ppc64_rma_size = ULONG_MAX; +} + +#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); +} + +struct change_mapping_params { + pte_t *pte; + unsigned long start; + unsigned long end; + unsigned long aligned_start; + unsigned long aligned_end; +}; + +static int __meminit stop_machine_change_mapping(void *data) +{ + struct change_mapping_params *params = + (struct change_mapping_params *)data; + + if (!data) + return -1; + + spin_unlock(&init_mm.page_table_lock); + pte_clear(&init_mm, params->aligned_start, params->pte); + create_physical_mapping(params->aligned_start, params->start, -1); + create_physical_mapping(params->end, params->aligned_end, -1); + spin_lock(&init_mm.page_table_lock); + return 0; +} + +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); + } +} + +/* + * clear the pte and potentially split the mapping helper + */ +static void __meminit split_kernel_mapping(unsigned long addr, unsigned long end, + unsigned long size, pte_t *pte) +{ + unsigned long mask = ~(size - 1); + unsigned long aligned_start = addr & mask; + unsigned long aligned_end = addr + size; + struct change_mapping_params params; + bool split_region = false; + + if ((end - addr) < size) { + /* + * We're going to clear the PTE, but not flushed + * the mapping, time to remap and flush. The + * effects if visible outside the processor or + * if we are running in code close to the + * mapping we cleared, we are in trouble. + */ + if (overlaps_kernel_text(aligned_start, addr) || + overlaps_kernel_text(end, aligned_end)) { + /* + * Hack, just return, don't pte_clear + */ + WARN_ONCE(1, "Linear mapping %lx->%lx overlaps kernel " + "text, not splitting\n", addr, end); + return; + } + split_region = true; + } + + if (split_region) { + params.pte = pte; + params.start = addr; + params.end = end; + params.aligned_start = addr & ~(size - 1); + params.aligned_end = min_t(unsigned long, aligned_end, + (unsigned long)__va(memblock_end_of_DRAM())); + stop_machine(stop_machine_change_mapping, ¶ms, NULL); + return; + } + + 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)) { + split_kernel_mapping(addr, end, PMD_SIZE, (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)) { + split_kernel_mapping(addr, end, PUD_SIZE, (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 __meminit 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)) { + split_kernel_mapping(addr, end, PGDIR_SIZE, (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 __meminit radix__create_section_mapping(unsigned long start, unsigned long end, int nid) +{ + if (end >= RADIX_VMALLOC_START) { + pr_warn("Outside the supported range\n"); + return -1; + } + + return create_physical_mapping(start, end, nid); +} + +int __meminit radix__remove_section_mapping(unsigned long start, unsigned long end) +{ + remove_pagetable(start, end); + return 0; +} +#endif /* CONFIG_MEMORY_HOTPLUG */ + +#ifdef CONFIG_SPARSEMEM_VMEMMAP +static int __map_kernel_page_nid(unsigned long ea, unsigned long pa, + pgprot_t flags, unsigned int map_page_size, + int nid) +{ + return __map_kernel_page(ea, pa, flags, map_page_size, nid, 0, 0); +} + +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; + int nid = early_pfn_to_nid(phys >> PAGE_SHIFT); + int ret; + + if ((start + page_size) >= RADIX_VMEMMAP_END) { + pr_warn("Outside the supported range\n"); + return -1; + } + + ret = __map_kernel_page_nid(start, phys, __pgprot(flags), page_size, nid); + BUG_ON(ret); + + return 0; +} + +#ifdef CONFIG_MEMORY_HOTPLUG +void __meminit 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(pmd_lockptr(mm, pmdp)); +#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 */ + +void radix__ptep_set_access_flags(struct vm_area_struct *vma, pte_t *ptep, + pte_t entry, unsigned long address, int psize) +{ + struct mm_struct *mm = vma->vm_mm; + unsigned long set = pte_val(entry) & (_PAGE_DIRTY | _PAGE_ACCESSED | + _PAGE_RW | _PAGE_EXEC); + + unsigned long change = pte_val(entry) ^ pte_val(*ptep); + /* + * To avoid NMMU hang while relaxing access, we need mark + * the pte invalid in between. + */ + if ((change & _PAGE_RW) && atomic_read(&mm->context.copros) > 0) { + unsigned long old_pte, new_pte; + + old_pte = __radix_pte_update(ptep, _PAGE_PRESENT, _PAGE_INVALID); + /* + * new value of pte + */ + new_pte = old_pte | set; + radix__flush_tlb_page_psize(mm, address, psize); + __radix_pte_update(ptep, _PAGE_INVALID, new_pte); + } else { + __radix_pte_update(ptep, 0, set); + /* + * Book3S does not require a TLB flush when relaxing access + * restrictions when the address space is not attached to a + * NMMU, because the core MMU will reload the pte after taking + * an access fault, which is defined by the architectue. + */ + } + /* See ptesync comment in radix__set_pte_at */ +} + +void radix__ptep_modify_prot_commit(struct vm_area_struct *vma, + unsigned long addr, pte_t *ptep, + pte_t old_pte, pte_t pte) +{ + struct mm_struct *mm = vma->vm_mm; + + /* + * To avoid NMMU hang while relaxing access we need to flush the tlb before + * we set the new value. We need to do this only for radix, because hash + * translation does flush when updating the linux pte. + */ + if (is_pte_rw_upgrade(pte_val(old_pte), pte_val(pte)) && + (atomic_read(&mm->context.copros) > 0)) + radix__flush_tlb_page(vma, addr); + + set_pte_at(mm, addr, ptep, pte); +} |