1/*
2 *  S390 version
3 *    Copyright IBM Corp. 1999
4 *    Author(s): Hartmut Penner (hp@de.ibm.com)
5 *
6 *  Derived from "arch/i386/mm/init.c"
7 *    Copyright (C) 1995  Linus Torvalds
8 */
9
10#include <linux/signal.h>
11#include <linux/sched.h>
12#include <linux/kernel.h>
13#include <linux/errno.h>
14#include <linux/string.h>
15#include <linux/types.h>
16#include <linux/ptrace.h>
17#include <linux/mman.h>
18#include <linux/mm.h>
19#include <linux/swap.h>
20#include <linux/smp.h>
21#include <linux/init.h>
22#include <linux/pagemap.h>
23#include <linux/bootmem.h>
24#include <linux/memory.h>
25#include <linux/pfn.h>
26#include <linux/poison.h>
27#include <linux/initrd.h>
28#include <linux/export.h>
29#include <linux/gfp.h>
30#include <asm/processor.h>
31#include <asm/uaccess.h>
32#include <asm/pgtable.h>
33#include <asm/pgalloc.h>
34#include <asm/dma.h>
35#include <asm/lowcore.h>
36#include <asm/tlb.h>
37#include <asm/tlbflush.h>
38#include <asm/sections.h>
39#include <asm/ctl_reg.h>
40#include <asm/sclp.h>
41
42pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE)));
43
44unsigned long empty_zero_page, zero_page_mask;
45EXPORT_SYMBOL(empty_zero_page);
46EXPORT_SYMBOL(zero_page_mask);
47
48static void __init setup_zero_pages(void)
49{
50	struct cpuid cpu_id;
51	unsigned int order;
52	struct page *page;
53	int i;
54
55	get_cpu_id(&cpu_id);
56	switch (cpu_id.machine) {
57	case 0x9672:	/* g5 */
58	case 0x2064:	/* z900 */
59	case 0x2066:	/* z900 */
60	case 0x2084:	/* z990 */
61	case 0x2086:	/* z990 */
62	case 0x2094:	/* z9-109 */
63	case 0x2096:	/* z9-109 */
64		order = 0;
65		break;
66	case 0x2097:	/* z10 */
67	case 0x2098:	/* z10 */
68	case 0x2817:	/* z196 */
69	case 0x2818:	/* z196 */
70		order = 2;
71		break;
72	case 0x2827:	/* zEC12 */
73	case 0x2828:	/* zEC12 */
74		order = 5;
75		break;
76	case 0x2964:	/* z13 */
77	default:
78		order = 7;
79		break;
80	}
81	/* Limit number of empty zero pages for small memory sizes */
82	while (order > 2 && (totalram_pages >> 10) < (1UL << order))
83		order--;
84
85	empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
86	if (!empty_zero_page)
87		panic("Out of memory in setup_zero_pages");
88
89	page = virt_to_page((void *) empty_zero_page);
90	split_page(page, order);
91	for (i = 1 << order; i > 0; i--) {
92		mark_page_reserved(page);
93		page++;
94	}
95
96	zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK;
97}
98
99/*
100 * paging_init() sets up the page tables
101 */
102void __init paging_init(void)
103{
104	unsigned long max_zone_pfns[MAX_NR_ZONES];
105	unsigned long pgd_type, asce_bits;
106
107	init_mm.pgd = swapper_pg_dir;
108	if (VMALLOC_END > (1UL << 42)) {
109		asce_bits = _ASCE_TYPE_REGION2 | _ASCE_TABLE_LENGTH;
110		pgd_type = _REGION2_ENTRY_EMPTY;
111	} else {
112		asce_bits = _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
113		pgd_type = _REGION3_ENTRY_EMPTY;
114	}
115	S390_lowcore.kernel_asce = (__pa(init_mm.pgd) & PAGE_MASK) | asce_bits;
116	clear_table((unsigned long *) init_mm.pgd, pgd_type,
117		    sizeof(unsigned long)*2048);
118	vmem_map_init();
119
120        /* enable virtual mapping in kernel mode */
121	__ctl_load(S390_lowcore.kernel_asce, 1, 1);
122	__ctl_load(S390_lowcore.kernel_asce, 7, 7);
123	__ctl_load(S390_lowcore.kernel_asce, 13, 13);
124	arch_local_irq_restore(4UL << (BITS_PER_LONG - 8));
125
126	sparse_memory_present_with_active_regions(MAX_NUMNODES);
127	sparse_init();
128	memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
129	max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
130	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
131	free_area_init_nodes(max_zone_pfns);
132}
133
134void __init mem_init(void)
135{
136	if (MACHINE_HAS_TLB_LC)
137		cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask);
138	cpumask_set_cpu(0, mm_cpumask(&init_mm));
139	atomic_set(&init_mm.context.attach_count, 1);
140
141        max_mapnr = max_low_pfn;
142        high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
143
144	/* Setup guest page hinting */
145	cmma_init();
146
147	/* this will put all low memory onto the freelists */
148	free_all_bootmem();
149	setup_zero_pages();	/* Setup zeroed pages. */
150
151	mem_init_print_info(NULL);
152	printk("Write protected kernel read-only data: %#lx - %#lx\n",
153	       (unsigned long)&_stext,
154	       PFN_ALIGN((unsigned long)&_eshared) - 1);
155}
156
157void free_initmem(void)
158{
159	free_initmem_default(POISON_FREE_INITMEM);
160}
161
162#ifdef CONFIG_BLK_DEV_INITRD
163void __init free_initrd_mem(unsigned long start, unsigned long end)
164{
165	free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
166			   "initrd");
167}
168#endif
169
170#ifdef CONFIG_MEMORY_HOTPLUG
171int arch_add_memory(int nid, u64 start, u64 size)
172{
173	unsigned long zone_start_pfn, zone_end_pfn, nr_pages;
174	unsigned long start_pfn = PFN_DOWN(start);
175	unsigned long size_pages = PFN_DOWN(size);
176	struct zone *zone;
177	int rc;
178
179	rc = vmem_add_mapping(start, size);
180	if (rc)
181		return rc;
182	for_each_zone(zone) {
183		if (zone_idx(zone) != ZONE_MOVABLE) {
184			/* Add range within existing zone limits */
185			zone_start_pfn = zone->zone_start_pfn;
186			zone_end_pfn = zone->zone_start_pfn +
187				       zone->spanned_pages;
188		} else {
189			/* Add remaining range to ZONE_MOVABLE */
190			zone_start_pfn = start_pfn;
191			zone_end_pfn = start_pfn + size_pages;
192		}
193		if (start_pfn < zone_start_pfn || start_pfn >= zone_end_pfn)
194			continue;
195		nr_pages = (start_pfn + size_pages > zone_end_pfn) ?
196			   zone_end_pfn - start_pfn : size_pages;
197		rc = __add_pages(nid, zone, start_pfn, nr_pages);
198		if (rc)
199			break;
200		start_pfn += nr_pages;
201		size_pages -= nr_pages;
202		if (!size_pages)
203			break;
204	}
205	if (rc)
206		vmem_remove_mapping(start, size);
207	return rc;
208}
209
210unsigned long memory_block_size_bytes(void)
211{
212	/*
213	 * Make sure the memory block size is always greater
214	 * or equal than the memory increment size.
215	 */
216	return max_t(unsigned long, MIN_MEMORY_BLOCK_SIZE, sclp_get_rzm());
217}
218
219#ifdef CONFIG_MEMORY_HOTREMOVE
220int arch_remove_memory(u64 start, u64 size)
221{
222	/*
223	 * There is no hardware or firmware interface which could trigger a
224	 * hot memory remove on s390. So there is nothing that needs to be
225	 * implemented.
226	 */
227	return -EBUSY;
228}
229#endif
230#endif /* CONFIG_MEMORY_HOTPLUG */
231