diff options
Diffstat (limited to 'arch/s390/mm/vmem.c')
| -rw-r--r-- | arch/s390/mm/vmem.c | 443 |
1 files changed, 443 insertions, 0 deletions
diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c new file mode 100644 index 000000000..db55561c5 --- /dev/null +++ b/arch/s390/mm/vmem.c @@ -0,0 +1,443 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright IBM Corp. 2006 + * Author(s): Heiko Carstens <heiko.carstens@de.ibm.com> + */ + +#include <linux/bootmem.h> +#include <linux/pfn.h> +#include <linux/mm.h> +#include <linux/init.h> +#include <linux/list.h> +#include <linux/hugetlb.h> +#include <linux/slab.h> +#include <linux/memblock.h> +#include <asm/cacheflush.h> +#include <asm/pgalloc.h> +#include <asm/pgtable.h> +#include <asm/setup.h> +#include <asm/tlbflush.h> +#include <asm/sections.h> +#include <asm/set_memory.h> + +static DEFINE_MUTEX(vmem_mutex); + +struct memory_segment { + struct list_head list; + unsigned long start; + unsigned long size; +}; + +static LIST_HEAD(mem_segs); + +static void __ref *vmem_alloc_pages(unsigned int order) +{ + unsigned long size = PAGE_SIZE << order; + + if (slab_is_available()) + return (void *)__get_free_pages(GFP_KERNEL, order); + return (void *) memblock_alloc(size, size); +} + +void *vmem_crst_alloc(unsigned long val) +{ + unsigned long *table; + + table = vmem_alloc_pages(CRST_ALLOC_ORDER); + if (table) + crst_table_init(table, val); + return table; +} + +pte_t __ref *vmem_pte_alloc(void) +{ + unsigned long size = PTRS_PER_PTE * sizeof(pte_t); + pte_t *pte; + + if (slab_is_available()) + pte = (pte_t *) page_table_alloc(&init_mm); + else + pte = (pte_t *) memblock_alloc(size, size); + if (!pte) + return NULL; + memset64((u64 *)pte, _PAGE_INVALID, PTRS_PER_PTE); + return pte; +} + +/* + * Add a physical memory range to the 1:1 mapping. + */ +static int vmem_add_mem(unsigned long start, unsigned long size) +{ + unsigned long pgt_prot, sgt_prot, r3_prot; + unsigned long pages4k, pages1m, pages2g; + unsigned long end = start + size; + unsigned long address = start; + pgd_t *pg_dir; + p4d_t *p4_dir; + pud_t *pu_dir; + pmd_t *pm_dir; + pte_t *pt_dir; + int ret = -ENOMEM; + + pgt_prot = pgprot_val(PAGE_KERNEL); + sgt_prot = pgprot_val(SEGMENT_KERNEL); + r3_prot = pgprot_val(REGION3_KERNEL); + if (!MACHINE_HAS_NX) { + pgt_prot &= ~_PAGE_NOEXEC; + sgt_prot &= ~_SEGMENT_ENTRY_NOEXEC; + r3_prot &= ~_REGION_ENTRY_NOEXEC; + } + pages4k = pages1m = pages2g = 0; + while (address < end) { + pg_dir = pgd_offset_k(address); + if (pgd_none(*pg_dir)) { + p4_dir = vmem_crst_alloc(_REGION2_ENTRY_EMPTY); + if (!p4_dir) + goto out; + pgd_populate(&init_mm, pg_dir, p4_dir); + } + p4_dir = p4d_offset(pg_dir, address); + if (p4d_none(*p4_dir)) { + pu_dir = vmem_crst_alloc(_REGION3_ENTRY_EMPTY); + if (!pu_dir) + goto out; + p4d_populate(&init_mm, p4_dir, pu_dir); + } + pu_dir = pud_offset(p4_dir, address); + if (MACHINE_HAS_EDAT2 && pud_none(*pu_dir) && address && + !(address & ~PUD_MASK) && (address + PUD_SIZE <= end) && + !debug_pagealloc_enabled()) { + pud_val(*pu_dir) = address | r3_prot; + address += PUD_SIZE; + pages2g++; + continue; + } + if (pud_none(*pu_dir)) { + pm_dir = vmem_crst_alloc(_SEGMENT_ENTRY_EMPTY); + if (!pm_dir) + goto out; + pud_populate(&init_mm, pu_dir, pm_dir); + } + pm_dir = pmd_offset(pu_dir, address); + if (MACHINE_HAS_EDAT1 && pmd_none(*pm_dir) && address && + !(address & ~PMD_MASK) && (address + PMD_SIZE <= end) && + !debug_pagealloc_enabled()) { + pmd_val(*pm_dir) = address | sgt_prot; + address += PMD_SIZE; + pages1m++; + continue; + } + if (pmd_none(*pm_dir)) { + pt_dir = vmem_pte_alloc(); + if (!pt_dir) + goto out; + pmd_populate(&init_mm, pm_dir, pt_dir); + } + + pt_dir = pte_offset_kernel(pm_dir, address); + pte_val(*pt_dir) = address | pgt_prot; + address += PAGE_SIZE; + pages4k++; + } + ret = 0; +out: + update_page_count(PG_DIRECT_MAP_4K, pages4k); + update_page_count(PG_DIRECT_MAP_1M, pages1m); + update_page_count(PG_DIRECT_MAP_2G, pages2g); + return ret; +} + +/* + * Remove a physical memory range from the 1:1 mapping. + * Currently only invalidates page table entries. + */ +static void vmem_remove_range(unsigned long start, unsigned long size) +{ + unsigned long pages4k, pages1m, pages2g; + unsigned long end = start + size; + unsigned long address = start; + pgd_t *pg_dir; + p4d_t *p4_dir; + pud_t *pu_dir; + pmd_t *pm_dir; + pte_t *pt_dir; + + pages4k = pages1m = pages2g = 0; + while (address < end) { + pg_dir = pgd_offset_k(address); + if (pgd_none(*pg_dir)) { + address += PGDIR_SIZE; + continue; + } + p4_dir = p4d_offset(pg_dir, address); + if (p4d_none(*p4_dir)) { + address += P4D_SIZE; + continue; + } + pu_dir = pud_offset(p4_dir, address); + if (pud_none(*pu_dir)) { + address += PUD_SIZE; + continue; + } + if (pud_large(*pu_dir)) { + pud_clear(pu_dir); + address += PUD_SIZE; + pages2g++; + continue; + } + pm_dir = pmd_offset(pu_dir, address); + if (pmd_none(*pm_dir)) { + address += PMD_SIZE; + continue; + } + if (pmd_large(*pm_dir)) { + pmd_clear(pm_dir); + address += PMD_SIZE; + pages1m++; + continue; + } + pt_dir = pte_offset_kernel(pm_dir, address); + pte_clear(&init_mm, address, pt_dir); + address += PAGE_SIZE; + pages4k++; + } + flush_tlb_kernel_range(start, end); + update_page_count(PG_DIRECT_MAP_4K, -pages4k); + update_page_count(PG_DIRECT_MAP_1M, -pages1m); + update_page_count(PG_DIRECT_MAP_2G, -pages2g); +} + +/* + * Add a backed mem_map array to the virtual mem_map array. + */ +int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, + struct vmem_altmap *altmap) +{ + unsigned long pgt_prot, sgt_prot; + unsigned long address = start; + pgd_t *pg_dir; + p4d_t *p4_dir; + pud_t *pu_dir; + pmd_t *pm_dir; + pte_t *pt_dir; + int ret = -ENOMEM; + + pgt_prot = pgprot_val(PAGE_KERNEL); + sgt_prot = pgprot_val(SEGMENT_KERNEL); + if (!MACHINE_HAS_NX) { + pgt_prot &= ~_PAGE_NOEXEC; + sgt_prot &= ~_SEGMENT_ENTRY_NOEXEC; + } + for (address = start; address < end;) { + pg_dir = pgd_offset_k(address); + if (pgd_none(*pg_dir)) { + p4_dir = vmem_crst_alloc(_REGION2_ENTRY_EMPTY); + if (!p4_dir) + goto out; + pgd_populate(&init_mm, pg_dir, p4_dir); + } + + p4_dir = p4d_offset(pg_dir, address); + if (p4d_none(*p4_dir)) { + pu_dir = vmem_crst_alloc(_REGION3_ENTRY_EMPTY); + if (!pu_dir) + goto out; + p4d_populate(&init_mm, p4_dir, pu_dir); + } + + pu_dir = pud_offset(p4_dir, address); + if (pud_none(*pu_dir)) { + pm_dir = vmem_crst_alloc(_SEGMENT_ENTRY_EMPTY); + if (!pm_dir) + goto out; + pud_populate(&init_mm, pu_dir, pm_dir); + } + + pm_dir = pmd_offset(pu_dir, address); + if (pmd_none(*pm_dir)) { + /* Use 1MB frames for vmemmap if available. We always + * use large frames even if they are only partially + * used. + * Otherwise we would have also page tables since + * vmemmap_populate gets called for each section + * separately. */ + if (MACHINE_HAS_EDAT1) { + void *new_page; + + new_page = vmemmap_alloc_block(PMD_SIZE, node); + if (!new_page) + goto out; + pmd_val(*pm_dir) = __pa(new_page) | sgt_prot; + address = (address + PMD_SIZE) & PMD_MASK; + continue; + } + pt_dir = vmem_pte_alloc(); + if (!pt_dir) + goto out; + pmd_populate(&init_mm, pm_dir, pt_dir); + } else if (pmd_large(*pm_dir)) { + address = (address + PMD_SIZE) & PMD_MASK; + continue; + } + + pt_dir = pte_offset_kernel(pm_dir, address); + if (pte_none(*pt_dir)) { + void *new_page; + + new_page = vmemmap_alloc_block(PAGE_SIZE, node); + if (!new_page) + goto out; + pte_val(*pt_dir) = __pa(new_page) | pgt_prot; + } + address += PAGE_SIZE; + } + ret = 0; +out: + return ret; +} + +void vmemmap_free(unsigned long start, unsigned long end, + struct vmem_altmap *altmap) +{ +} + +/* + * Add memory segment to the segment list if it doesn't overlap with + * an already present segment. + */ +static int insert_memory_segment(struct memory_segment *seg) +{ + struct memory_segment *tmp; + + if (seg->start + seg->size > VMEM_MAX_PHYS || + seg->start + seg->size < seg->start) + return -ERANGE; + + list_for_each_entry(tmp, &mem_segs, list) { + if (seg->start >= tmp->start + tmp->size) + continue; + if (seg->start + seg->size <= tmp->start) + continue; + return -ENOSPC; + } + list_add(&seg->list, &mem_segs); + return 0; +} + +/* + * Remove memory segment from the segment list. + */ +static void remove_memory_segment(struct memory_segment *seg) +{ + list_del(&seg->list); +} + +static void __remove_shared_memory(struct memory_segment *seg) +{ + remove_memory_segment(seg); + vmem_remove_range(seg->start, seg->size); +} + +int vmem_remove_mapping(unsigned long start, unsigned long size) +{ + struct memory_segment *seg; + int ret; + + mutex_lock(&vmem_mutex); + + ret = -ENOENT; + list_for_each_entry(seg, &mem_segs, list) { + if (seg->start == start && seg->size == size) + break; + } + + if (seg->start != start || seg->size != size) + goto out; + + ret = 0; + __remove_shared_memory(seg); + kfree(seg); +out: + mutex_unlock(&vmem_mutex); + return ret; +} + +int vmem_add_mapping(unsigned long start, unsigned long size) +{ + struct memory_segment *seg; + int ret; + + mutex_lock(&vmem_mutex); + ret = -ENOMEM; + seg = kzalloc(sizeof(*seg), GFP_KERNEL); + if (!seg) + goto out; + seg->start = start; + seg->size = size; + + ret = insert_memory_segment(seg); + if (ret) + goto out_free; + + ret = vmem_add_mem(start, size); + if (ret) + goto out_remove; + goto out; + +out_remove: + __remove_shared_memory(seg); +out_free: + kfree(seg); +out: + mutex_unlock(&vmem_mutex); + return ret; +} + +/* + * map whole physical memory to virtual memory (identity mapping) + * we reserve enough space in the vmalloc area for vmemmap to hotplug + * additional memory segments. + */ +void __init vmem_map_init(void) +{ + struct memblock_region *reg; + + for_each_memblock(memory, reg) + vmem_add_mem(reg->base, reg->size); + __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); + pr_info("Write protected kernel read-only data: %luk\n", + (unsigned long)(__end_rodata - _stext) >> 10); +} + +/* + * Convert memblock.memory to a memory segment list so there is a single + * list that contains all memory segments. + */ +static int __init vmem_convert_memory_chunk(void) +{ + struct memblock_region *reg; + struct memory_segment *seg; + + mutex_lock(&vmem_mutex); + for_each_memblock(memory, reg) { + seg = kzalloc(sizeof(*seg), GFP_KERNEL); + if (!seg) + panic("Out of memory...\n"); + seg->start = reg->base; + seg->size = reg->size; + insert_memory_segment(seg); + } + mutex_unlock(&vmem_mutex); + return 0; +} + +core_initcall(vmem_convert_memory_chunk); |