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-rw-r--r--kernel/arch/s390/mm/vmem.c416
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);