Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

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);