diff options
Diffstat (limited to 'kernel/arch/s390/mm/vmem.c')
| -rw-r--r-- | kernel/arch/s390/mm/vmem.c | 416 |
1 files changed, 416 insertions, 0 deletions
diff --git a/kernel/arch/s390/mm/vmem.c b/kernel/arch/s390/mm/vmem.c new file mode 100644 index 000000000..ef7d6c8fe --- /dev/null +++ b/kernel/arch/s390/mm/vmem.c @@ -0,0 +1,416 @@ +/* + * 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/module.h> +#include <linux/list.h> +#include <linux/hugetlb.h> +#include <linux/slab.h> +#include <linux/memblock.h> +#include <asm/pgalloc.h> +#include <asm/pgtable.h> +#include <asm/setup.h> +#include <asm/tlbflush.h> +#include <asm/sections.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) +{ + if (slab_is_available()) + return (void *)__get_free_pages(GFP_KERNEL, order); + return alloc_bootmem_pages((1 << order) * PAGE_SIZE); +} + +static inline pud_t *vmem_pud_alloc(void) +{ + pud_t *pud = NULL; + + pud = vmem_alloc_pages(2); + if (!pud) + return NULL; + clear_table((unsigned long *) pud, _REGION3_ENTRY_EMPTY, PAGE_SIZE * 4); + return pud; +} + +static inline pmd_t *vmem_pmd_alloc(void) +{ + pmd_t *pmd = NULL; + + pmd = vmem_alloc_pages(2); + if (!pmd) + return NULL; + clear_table((unsigned long *) pmd, _SEGMENT_ENTRY_EMPTY, PAGE_SIZE * 4); + return pmd; +} + +static pte_t __ref *vmem_pte_alloc(unsigned long address) +{ + pte_t *pte; + + if (slab_is_available()) + pte = (pte_t *) page_table_alloc(&init_mm); + else + pte = alloc_bootmem_align(PTRS_PER_PTE * sizeof(pte_t), + PTRS_PER_PTE * sizeof(pte_t)); + if (!pte) + return NULL; + clear_table((unsigned long *) pte, _PAGE_INVALID, + PTRS_PER_PTE * sizeof(pte_t)); + return pte; +} + +/* + * Add a physical memory range to the 1:1 mapping. + */ +static int vmem_add_mem(unsigned long start, unsigned long size, int ro) +{ + unsigned long end = start + size; + unsigned long address = start; + pgd_t *pg_dir; + pud_t *pu_dir; + pmd_t *pm_dir; + pte_t *pt_dir; + int ret = -ENOMEM; + + while (address < end) { + pg_dir = pgd_offset_k(address); + if (pgd_none(*pg_dir)) { + pu_dir = vmem_pud_alloc(); + if (!pu_dir) + goto out; + pgd_populate(&init_mm, pg_dir, pu_dir); + } + pu_dir = pud_offset(pg_dir, address); +#ifndef CONFIG_DEBUG_PAGEALLOC + if (MACHINE_HAS_EDAT2 && pud_none(*pu_dir) && address && + !(address & ~PUD_MASK) && (address + PUD_SIZE <= end)) { + pud_val(*pu_dir) = __pa(address) | + _REGION_ENTRY_TYPE_R3 | _REGION3_ENTRY_LARGE | + (ro ? _REGION_ENTRY_PROTECT : 0); + address += PUD_SIZE; + continue; + } +#endif + if (pud_none(*pu_dir)) { + pm_dir = vmem_pmd_alloc(); + if (!pm_dir) + goto out; + pud_populate(&init_mm, pu_dir, pm_dir); + } + pm_dir = pmd_offset(pu_dir, address); +#ifndef CONFIG_DEBUG_PAGEALLOC + if (MACHINE_HAS_EDAT1 && pmd_none(*pm_dir) && address && + !(address & ~PMD_MASK) && (address + PMD_SIZE <= end)) { + pmd_val(*pm_dir) = __pa(address) | + _SEGMENT_ENTRY | _SEGMENT_ENTRY_LARGE | + _SEGMENT_ENTRY_YOUNG | + (ro ? _SEGMENT_ENTRY_PROTECT : 0); + address += PMD_SIZE; + continue; + } +#endif + if (pmd_none(*pm_dir)) { + pt_dir = vmem_pte_alloc(address); + 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) = __pa(address) | + pgprot_val(ro ? PAGE_KERNEL_RO : PAGE_KERNEL); + address += PAGE_SIZE; + } + ret = 0; +out: + 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 end = start + size; + unsigned long address = start; + pgd_t *pg_dir; + pud_t *pu_dir; + pmd_t *pm_dir; + pte_t *pt_dir; + pte_t pte; + + pte_val(pte) = _PAGE_INVALID; + while (address < end) { + pg_dir = pgd_offset_k(address); + if (pgd_none(*pg_dir)) { + address += PGDIR_SIZE; + continue; + } + pu_dir = pud_offset(pg_dir, address); + if (pud_none(*pu_dir)) { + address += PUD_SIZE; + continue; + } + if (pud_large(*pu_dir)) { + pud_clear(pu_dir); + address += PUD_SIZE; + 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; + continue; + } + pt_dir = pte_offset_kernel(pm_dir, address); + *pt_dir = pte; + address += PAGE_SIZE; + } + flush_tlb_kernel_range(start, end); +} + +/* + * Add a backed mem_map array to the virtual mem_map array. + */ +int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node) +{ + unsigned long address = start; + pgd_t *pg_dir; + pud_t *pu_dir; + pmd_t *pm_dir; + pte_t *pt_dir; + int ret = -ENOMEM; + + for (address = start; address < end;) { + pg_dir = pgd_offset_k(address); + if (pgd_none(*pg_dir)) { + pu_dir = vmem_pud_alloc(); + if (!pu_dir) + goto out; + pgd_populate(&init_mm, pg_dir, pu_dir); + } + + pu_dir = pud_offset(pg_dir, address); + if (pud_none(*pu_dir)) { + pm_dir = vmem_pmd_alloc(); + 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) | + _SEGMENT_ENTRY | _SEGMENT_ENTRY_LARGE; + address = (address + PMD_SIZE) & PMD_MASK; + continue; + } + pt_dir = vmem_pte_alloc(address); + 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) | pgprot_val(PAGE_KERNEL); + } + address += PAGE_SIZE; + } + ret = 0; +out: + return ret; +} + +void vmemmap_free(unsigned long start, unsigned long end) +{ +} + +/* + * 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, 0); + 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) +{ + unsigned long ro_start, ro_end; + struct memblock_region *reg; + phys_addr_t start, end; + + ro_start = PFN_ALIGN((unsigned long)&_stext); + ro_end = (unsigned long)&_eshared & PAGE_MASK; + for_each_memblock(memory, reg) { + start = reg->base; + end = reg->base + reg->size - 1; + if (start >= ro_end || end <= ro_start) + vmem_add_mem(start, end - start, 0); + else if (start >= ro_start && end <= ro_end) + vmem_add_mem(start, end - start, 1); + else if (start >= ro_start) { + vmem_add_mem(start, ro_end - start, 1); + vmem_add_mem(ro_end, end - ro_end, 0); + } else if (end < ro_end) { + vmem_add_mem(start, ro_start - start, 0); + vmem_add_mem(ro_start, end - ro_start, 1); + } else { + vmem_add_mem(start, ro_start - start, 0); + vmem_add_mem(ro_start, ro_end - ro_start, 1); + vmem_add_mem(ro_end, end - ro_end, 0); + } + } +} + +/* + * 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); |