1 files changed, 313 insertions, 0 deletions
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
new file mode 100644
index 0000000000..8b94d2212d
--- /dev/null
+++ b/arch/s390/mm/init.c
@@ -0,0 +1,313 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  S390 version
+ *    Copyright IBM Corp. 1999
+ *    Author(s): Hartmut Penner (hp@de.ibm.com)
+ *
+ *  Derived from "arch/i386/mm/init.c"
+ *    Copyright (C) 1995  Linus Torvalds
+ */
+
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/ptrace.h>
+#include <linux/mman.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/swiotlb.h>
+#include <linux/smp.h>
+#include <linux/init.h>
+#include <linux/pagemap.h>
+#include <linux/memblock.h>
+#include <linux/memory.h>
+#include <linux/pfn.h>
+#include <linux/poison.h>
+#include <linux/initrd.h>
+#include <linux/export.h>
+#include <linux/cma.h>
+#include <linux/gfp.h>
+#include <linux/dma-direct.h>
+#include <linux/percpu.h>
+#include <asm/processor.h>
+#include <linux/uaccess.h>
+#include <asm/pgalloc.h>
+#include <asm/kfence.h>
+#include <asm/ptdump.h>
+#include <asm/dma.h>
+#include <asm/abs_lowcore.h>
+#include <asm/tlb.h>
+#include <asm/tlbflush.h>
+#include <asm/sections.h>
+#include <asm/ctl_reg.h>
+#include <asm/sclp.h>
+#include <asm/set_memory.h>
+#include <asm/kasan.h>
+#include <asm/dma-mapping.h>
+#include <asm/uv.h>
+#include <linux/virtio_anchor.h>
+#include <linux/virtio_config.h>
+
+pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(".bss..swapper_pg_dir");
+pgd_t invalid_pg_dir[PTRS_PER_PGD] __section(".bss..invalid_pg_dir");
+
+unsigned long __bootdata_preserved(s390_invalid_asce);
+
+unsigned long empty_zero_page, zero_page_mask;
+EXPORT_SYMBOL(empty_zero_page);
+EXPORT_SYMBOL(zero_page_mask);
+
+static void __init setup_zero_pages(void)
+{
+	unsigned int order;
+	struct page *page;
+	int i;
+
+	/* Latest machines require a mapping granularity of 512KB */
+	order = 7;
+
+	/* Limit number of empty zero pages for small memory sizes */
+	while (order > 2 && (totalram_pages() >> 10) < (1UL << order))
+		order--;
+
+	empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
+	if (!empty_zero_page)
+		panic("Out of memory in setup_zero_pages");
+
+	page = virt_to_page((void *) empty_zero_page);
+	split_page(page, order);
+	for (i = 1 << order; i > 0; i--) {
+		mark_page_reserved(page);
+		page++;
+	}
+
+	zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK;
+}
+
+/*
+ * paging_init() sets up the page tables
+ */
+void __init paging_init(void)
+{
+	unsigned long max_zone_pfns[MAX_NR_ZONES];
+
+	vmem_map_init();
+	sparse_init();
+	zone_dma_bits = 31;
+	memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
+	max_zone_pfns[ZONE_DMA] = virt_to_pfn(MAX_DMA_ADDRESS);
+	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
+	free_area_init(max_zone_pfns);
+}
+
+void mark_rodata_ro(void)
+{
+	unsigned long size = __end_ro_after_init - __start_ro_after_init;
+
+	__set_memory_ro(__start_ro_after_init, __end_ro_after_init);
+	pr_info("Write protected read-only-after-init data: %luk\n", size >> 10);
+	debug_checkwx();
+}
+
+int set_memory_encrypted(unsigned long vaddr, int numpages)
+{
+	int i;
+
+	/* make specified pages unshared, (swiotlb, dma_free) */
+	for (i = 0; i < numpages; ++i) {
+		uv_remove_shared(virt_to_phys((void *)vaddr));
+		vaddr += PAGE_SIZE;
+	}
+	return 0;
+}
+
+int set_memory_decrypted(unsigned long vaddr, int numpages)
+{
+	int i;
+	/* make specified pages shared (swiotlb, dma_alloca) */
+	for (i = 0; i < numpages; ++i) {
+		uv_set_shared(virt_to_phys((void *)vaddr));
+		vaddr += PAGE_SIZE;
+	}
+	return 0;
+}
+
+/* are we a protected virtualization guest? */
+bool force_dma_unencrypted(struct device *dev)
+{
+	return is_prot_virt_guest();
+}
+
+/* protected virtualization */
+static void pv_init(void)
+{
+	if (!is_prot_virt_guest())
+		return;
+
+	virtio_set_mem_acc_cb(virtio_require_restricted_mem_acc);
+
+	/* make sure bounce buffers are shared */
+	swiotlb_init(true, SWIOTLB_FORCE | SWIOTLB_VERBOSE);
+	swiotlb_update_mem_attributes();
+}
+
+void __init mem_init(void)
+{
+	cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask);
+	cpumask_set_cpu(0, mm_cpumask(&init_mm));
+
+	set_max_mapnr(max_low_pfn);
+        high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
+
+	pv_init();
+	kfence_split_mapping();
+	/* Setup guest page hinting */
+	cmma_init();
+
+	/* this will put all low memory onto the freelists */
+	memblock_free_all();
+	setup_zero_pages();	/* Setup zeroed pages. */
+
+	cmma_init_nodat();
+}
+
+void free_initmem(void)
+{
+	set_memory_rwnx((unsigned long)_sinittext,
+			(unsigned long)(_einittext - _sinittext) >> PAGE_SHIFT);
+	free_initmem_default(POISON_FREE_INITMEM);
+}
+
+unsigned long memory_block_size_bytes(void)
+{
+	/*
+	 * Make sure the memory block size is always greater
+	 * or equal than the memory increment size.
+	 */
+	return max_t(unsigned long, MIN_MEMORY_BLOCK_SIZE, sclp.rzm);
+}
+
+unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
+EXPORT_SYMBOL(__per_cpu_offset);
+
+static int __init pcpu_cpu_distance(unsigned int from, unsigned int to)
+{
+	return LOCAL_DISTANCE;
+}
+
+static int __init pcpu_cpu_to_node(int cpu)
+{
+	return 0;
+}
+
+void __init setup_per_cpu_areas(void)
+{
+	unsigned long delta;
+	unsigned int cpu;
+	int rc;
+
+	/*
+	 * Always reserve area for module percpu variables.  That's
+	 * what the legacy allocator did.
+	 */
+	rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE,
+				    PERCPU_DYNAMIC_RESERVE, PAGE_SIZE,
+				    pcpu_cpu_distance,
+				    pcpu_cpu_to_node);
+	if (rc < 0)
+		panic("Failed to initialize percpu areas.");
+
+	delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;
+	for_each_possible_cpu(cpu)
+		__per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu];
+}
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+
+#ifdef CONFIG_CMA
+
+/* Prevent memory blocks which contain cma regions from going offline */
+
+struct s390_cma_mem_data {
+	unsigned long start;
+	unsigned long end;
+};
+
+static int s390_cma_check_range(struct cma *cma, void *data)
+{
+	struct s390_cma_mem_data *mem_data;
+	unsigned long start, end;
+
+	mem_data = data;
+	start = cma_get_base(cma);
+	end = start + cma_get_size(cma);
+	if (end < mem_data->start)
+		return 0;
+	if (start >= mem_data->end)
+		return 0;
+	return -EBUSY;
+}
+
+static int s390_cma_mem_notifier(struct notifier_block *nb,
+				 unsigned long action, void *data)
+{
+	struct s390_cma_mem_data mem_data;
+	struct memory_notify *arg;
+	int rc = 0;
+
+	arg = data;
+	mem_data.start = arg->start_pfn << PAGE_SHIFT;
+	mem_data.end = mem_data.start + (arg->nr_pages << PAGE_SHIFT);
+	if (action == MEM_GOING_OFFLINE)
+		rc = cma_for_each_area(s390_cma_check_range, &mem_data);
+	return notifier_from_errno(rc);
+}
+
+static struct notifier_block s390_cma_mem_nb = {
+	.notifier_call = s390_cma_mem_notifier,
+};
+
+static int __init s390_cma_mem_init(void)
+{
+	return register_memory_notifier(&s390_cma_mem_nb);
+}
+device_initcall(s390_cma_mem_init);
+
+#endif /* CONFIG_CMA */
+
+int arch_add_memory(int nid, u64 start, u64 size,
+		    struct mhp_params *params)
+{
+	unsigned long start_pfn = PFN_DOWN(start);
+	unsigned long size_pages = PFN_DOWN(size);
+	int rc;
+
+	if (WARN_ON_ONCE(params->altmap))
+		return -EINVAL;
+
+	if (WARN_ON_ONCE(params->pgprot.pgprot != PAGE_KERNEL.pgprot))
+		return -EINVAL;
+
+	VM_BUG_ON(!mhp_range_allowed(start, size, true));
+	rc = vmem_add_mapping(start, size);
+	if (rc)
+		return rc;
+
+	rc = __add_pages(nid, start_pfn, size_pages, params);
+	if (rc)
+		vmem_remove_mapping(start, size);
+	return rc;
+}
+
+void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
+{
+	unsigned long start_pfn = start >> PAGE_SHIFT;
+	unsigned long nr_pages = size >> PAGE_SHIFT;
+
+	__remove_pages(start_pfn, nr_pages, altmap);
+	vmem_remove_mapping(start, size);
+}
+#endif /* CONFIG_MEMORY_HOTPLUG */