Initial import

1 files changed, 416 insertions, 0 deletions

diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c
new file mode 100644
index 000000000..ef7d6c8fe
--- /dev/null
+++ b/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);