xref: /openbmc/linux/arch/s390/mm/init.c (revision 64c70b1c)
1 /*
2  *  arch/s390/mm/init.c
3  *
4  *  S390 version
5  *    Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
6  *    Author(s): Hartmut Penner (hp@de.ibm.com)
7  *
8  *  Derived from "arch/i386/mm/init.c"
9  *    Copyright (C) 1995  Linus Torvalds
10  */
11 
12 #include <linux/signal.h>
13 #include <linux/sched.h>
14 #include <linux/kernel.h>
15 #include <linux/errno.h>
16 #include <linux/string.h>
17 #include <linux/types.h>
18 #include <linux/ptrace.h>
19 #include <linux/mman.h>
20 #include <linux/mm.h>
21 #include <linux/swap.h>
22 #include <linux/smp.h>
23 #include <linux/init.h>
24 #include <linux/pagemap.h>
25 #include <linux/bootmem.h>
26 #include <linux/pfn.h>
27 #include <linux/poison.h>
28 #include <linux/initrd.h>
29 #include <asm/processor.h>
30 #include <asm/system.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 
40 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
41 
42 pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE)));
43 char  empty_zero_page[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
44 
45 void diag10(unsigned long addr)
46 {
47         if (addr >= 0x7ff00000)
48                 return;
49 	asm volatile(
50 #ifdef CONFIG_64BIT
51 		"	sam31\n"
52 		"	diag	%0,%0,0x10\n"
53 		"0:	sam64\n"
54 #else
55 		"	diag	%0,%0,0x10\n"
56 		"0:\n"
57 #endif
58 		EX_TABLE(0b,0b)
59 		: : "a" (addr));
60 }
61 
62 void show_mem(void)
63 {
64 	int i, total = 0, reserved = 0;
65 	int shared = 0, cached = 0;
66 	struct page *page;
67 
68 	printk("Mem-info:\n");
69 	show_free_areas();
70 	printk("Free swap:       %6ldkB\n", nr_swap_pages << (PAGE_SHIFT - 10));
71 	i = max_mapnr;
72 	while (i-- > 0) {
73 		if (!pfn_valid(i))
74 			continue;
75 		page = pfn_to_page(i);
76 		total++;
77 		if (PageReserved(page))
78 			reserved++;
79 		else if (PageSwapCache(page))
80 			cached++;
81 		else if (page_count(page))
82 			shared += page_count(page) - 1;
83 	}
84 	printk("%d pages of RAM\n", total);
85 	printk("%d reserved pages\n", reserved);
86 	printk("%d pages shared\n", shared);
87 	printk("%d pages swap cached\n", cached);
88 
89 	printk("%lu pages dirty\n", global_page_state(NR_FILE_DIRTY));
90 	printk("%lu pages writeback\n", global_page_state(NR_WRITEBACK));
91 	printk("%lu pages mapped\n", global_page_state(NR_FILE_MAPPED));
92 	printk("%lu pages slab\n",
93 	       global_page_state(NR_SLAB_RECLAIMABLE) +
94 	       global_page_state(NR_SLAB_UNRECLAIMABLE));
95 	printk("%lu pages pagetables\n", global_page_state(NR_PAGETABLE));
96 }
97 
98 static void __init setup_ro_region(void)
99 {
100 	pgd_t *pgd;
101 	pmd_t *pmd;
102 	pte_t *pte;
103 	pte_t new_pte;
104 	unsigned long address, end;
105 
106 	address = ((unsigned long)&_stext) & PAGE_MASK;
107 	end = PFN_ALIGN((unsigned long)&_eshared);
108 
109 	for (; address < end; address += PAGE_SIZE) {
110 		pgd = pgd_offset_k(address);
111 		pmd = pmd_offset(pgd, address);
112 		pte = pte_offset_kernel(pmd, address);
113 		new_pte = mk_pte_phys(address, __pgprot(_PAGE_RO));
114 		*pte = new_pte;
115 	}
116 }
117 
118 /*
119  * paging_init() sets up the page tables
120  */
121 void __init paging_init(void)
122 {
123 	pgd_t *pg_dir;
124 	int i;
125 	unsigned long pgdir_k;
126 	static const int ssm_mask = 0x04000000L;
127 	unsigned long max_zone_pfns[MAX_NR_ZONES];
128 
129 	pg_dir = swapper_pg_dir;
130 
131 #ifdef CONFIG_64BIT
132 	pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) | _KERN_REGION_TABLE;
133 	for (i = 0; i < PTRS_PER_PGD; i++)
134 		pgd_clear_kernel(pg_dir + i);
135 #else
136 	pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) | _KERNSEG_TABLE;
137 	for (i = 0; i < PTRS_PER_PGD; i++)
138 		pmd_clear_kernel((pmd_t *)(pg_dir + i));
139 #endif
140 	vmem_map_init();
141 	setup_ro_region();
142 
143 	S390_lowcore.kernel_asce = pgdir_k;
144 
145         /* enable virtual mapping in kernel mode */
146 	__ctl_load(pgdir_k, 1, 1);
147 	__ctl_load(pgdir_k, 7, 7);
148 	__ctl_load(pgdir_k, 13, 13);
149 	__raw_local_irq_ssm(ssm_mask);
150 
151 	memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
152 #ifdef CONFIG_ZONE_DMA
153 	max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
154 #endif
155 	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
156 	free_area_init_nodes(max_zone_pfns);
157 }
158 
159 void __init mem_init(void)
160 {
161 	unsigned long codesize, reservedpages, datasize, initsize;
162 
163         max_mapnr = num_physpages = max_low_pfn;
164         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
165 
166         /* clear the zero-page */
167         memset(empty_zero_page, 0, PAGE_SIZE);
168 
169 	/* this will put all low memory onto the freelists */
170 	totalram_pages += free_all_bootmem();
171 
172 	reservedpages = 0;
173 
174 	codesize =  (unsigned long) &_etext - (unsigned long) &_text;
175 	datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
176 	initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
177         printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, %ldk data, %ldk init)\n",
178                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
179                 max_mapnr << (PAGE_SHIFT-10),
180                 codesize >> 10,
181                 reservedpages << (PAGE_SHIFT-10),
182                 datasize >>10,
183                 initsize >> 10);
184 	printk("Write protected kernel read-only data: %#lx - %#lx\n",
185 	       (unsigned long)&_stext,
186 	       PFN_ALIGN((unsigned long)&_eshared) - 1);
187 }
188 
189 void free_initmem(void)
190 {
191         unsigned long addr;
192 
193         addr = (unsigned long)(&__init_begin);
194         for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
195 		ClearPageReserved(virt_to_page(addr));
196 		init_page_count(virt_to_page(addr));
197 		memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE);
198 		free_page(addr);
199 		totalram_pages++;
200         }
201         printk ("Freeing unused kernel memory: %ldk freed\n",
202 		((unsigned long)&__init_end - (unsigned long)&__init_begin) >> 10);
203 }
204 
205 #ifdef CONFIG_BLK_DEV_INITRD
206 void free_initrd_mem(unsigned long start, unsigned long end)
207 {
208         if (start < end)
209                 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
210         for (; start < end; start += PAGE_SIZE) {
211                 ClearPageReserved(virt_to_page(start));
212                 init_page_count(virt_to_page(start));
213                 free_page(start);
214                 totalram_pages++;
215         }
216 }
217 #endif
218