xref: /openbmc/linux/arch/s390/mm/init.c (revision 87c2ce3b)
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/config.h>
13 #include <linux/signal.h>
14 #include <linux/sched.h>
15 #include <linux/kernel.h>
16 #include <linux/errno.h>
17 #include <linux/string.h>
18 #include <linux/types.h>
19 #include <linux/ptrace.h>
20 #include <linux/mman.h>
21 #include <linux/mm.h>
22 #include <linux/swap.h>
23 #include <linux/smp.h>
24 #include <linux/init.h>
25 #include <linux/pagemap.h>
26 #include <linux/bootmem.h>
27 
28 #include <asm/processor.h>
29 #include <asm/system.h>
30 #include <asm/uaccess.h>
31 #include <asm/pgtable.h>
32 #include <asm/pgalloc.h>
33 #include <asm/dma.h>
34 #include <asm/lowcore.h>
35 #include <asm/tlb.h>
36 #include <asm/tlbflush.h>
37 
38 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
39 
40 pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE)));
41 char  empty_zero_page[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
42 
43 void diag10(unsigned long addr)
44 {
45         if (addr >= 0x7ff00000)
46                 return;
47 #ifdef CONFIG_64BIT
48         asm volatile (
49 		"   sam31\n"
50 		"   diag %0,%0,0x10\n"
51 		"0: sam64\n"
52 		".section __ex_table,\"a\"\n"
53 		"   .align 8\n"
54 		"   .quad 0b, 0b\n"
55 		".previous\n"
56 		: : "a" (addr));
57 #else
58         asm volatile (
59 		"   diag %0,%0,0x10\n"
60 		"0:\n"
61 		".section __ex_table,\"a\"\n"
62 		"   .align 4\n"
63 		"   .long 0b, 0b\n"
64 		".previous\n"
65 		: : "a" (addr));
66 #endif
67 }
68 
69 void show_mem(void)
70 {
71         int i, total = 0, reserved = 0;
72         int shared = 0, cached = 0;
73 
74         printk("Mem-info:\n");
75         show_free_areas();
76         printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
77         i = max_mapnr;
78         while (i-- > 0) {
79                 total++;
80                 if (PageReserved(mem_map+i))
81                         reserved++;
82                 else if (PageSwapCache(mem_map+i))
83                         cached++;
84                 else if (page_count(mem_map+i))
85                         shared += page_count(mem_map+i) - 1;
86         }
87         printk("%d pages of RAM\n",total);
88         printk("%d reserved pages\n",reserved);
89         printk("%d pages shared\n",shared);
90         printk("%d pages swap cached\n",cached);
91 }
92 
93 /* References to section boundaries */
94 
95 extern unsigned long _text;
96 extern unsigned long _etext;
97 extern unsigned long _edata;
98 extern unsigned long __bss_start;
99 extern unsigned long _end;
100 
101 extern unsigned long __init_begin;
102 extern unsigned long __init_end;
103 
104 extern unsigned long __initdata zholes_size[];
105 /*
106  * paging_init() sets up the page tables
107  */
108 
109 #ifndef CONFIG_64BIT
110 void __init paging_init(void)
111 {
112         pgd_t * pg_dir;
113         pte_t * pg_table;
114         pte_t   pte;
115 	int     i;
116         unsigned long tmp;
117         unsigned long pfn = 0;
118         unsigned long pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) | _KERNSEG_TABLE;
119         static const int ssm_mask = 0x04000000L;
120 
121 	/* unmap whole virtual address space */
122 
123         pg_dir = swapper_pg_dir;
124 
125 	for (i=0;i<KERNEL_PGD_PTRS;i++)
126 	        pmd_clear((pmd_t*)pg_dir++);
127 
128 	/*
129 	 * map whole physical memory to virtual memory (identity mapping)
130 	 */
131 
132         pg_dir = swapper_pg_dir;
133 
134         while (pfn < max_low_pfn) {
135                 /*
136                  * pg_table is physical at this point
137                  */
138 		pg_table = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
139 
140                 pg_dir->pgd0 =  (_PAGE_TABLE | __pa(pg_table));
141                 pg_dir->pgd1 =  (_PAGE_TABLE | (__pa(pg_table)+1024));
142                 pg_dir->pgd2 =  (_PAGE_TABLE | (__pa(pg_table)+2048));
143                 pg_dir->pgd3 =  (_PAGE_TABLE | (__pa(pg_table)+3072));
144                 pg_dir++;
145 
146                 for (tmp = 0 ; tmp < PTRS_PER_PTE ; tmp++,pg_table++) {
147                         pte = pfn_pte(pfn, PAGE_KERNEL);
148                         if (pfn >= max_low_pfn)
149                                 pte_clear(&init_mm, 0, &pte);
150                         set_pte(pg_table, pte);
151                         pfn++;
152                 }
153         }
154 
155 	S390_lowcore.kernel_asce = pgdir_k;
156 
157         /* enable virtual mapping in kernel mode */
158         __asm__ __volatile__("    LCTL  1,1,%0\n"
159                              "    LCTL  7,7,%0\n"
160                              "    LCTL  13,13,%0\n"
161                              "    SSM   %1"
162 			     : : "m" (pgdir_k), "m" (ssm_mask));
163 
164         local_flush_tlb();
165 
166 	{
167 		unsigned long zones_size[MAX_NR_ZONES];
168 
169 		memset(zones_size, 0, sizeof(zones_size));
170 		zones_size[ZONE_DMA] = max_low_pfn;
171 		free_area_init_node(0, &contig_page_data, zones_size,
172 				    __pa(PAGE_OFFSET) >> PAGE_SHIFT,
173 				    zholes_size);
174 	}
175         return;
176 }
177 
178 #else /* CONFIG_64BIT */
179 void __init paging_init(void)
180 {
181         pgd_t * pg_dir;
182 	pmd_t * pm_dir;
183         pte_t * pt_dir;
184         pte_t   pte;
185 	int     i,j,k;
186         unsigned long pfn = 0;
187         unsigned long pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) |
188           _KERN_REGION_TABLE;
189 	static const int ssm_mask = 0x04000000L;
190 
191 	unsigned long zones_size[MAX_NR_ZONES];
192 	unsigned long dma_pfn, high_pfn;
193 
194 	memset(zones_size, 0, sizeof(zones_size));
195 	dma_pfn = MAX_DMA_ADDRESS >> PAGE_SHIFT;
196 	high_pfn = max_low_pfn;
197 
198 	if (dma_pfn > high_pfn)
199 		zones_size[ZONE_DMA] = high_pfn;
200 	else {
201 		zones_size[ZONE_DMA] = dma_pfn;
202 		zones_size[ZONE_NORMAL] = high_pfn - dma_pfn;
203 	}
204 
205 	/* Initialize mem_map[].  */
206 	free_area_init_node(0, &contig_page_data, zones_size,
207 			    __pa(PAGE_OFFSET) >> PAGE_SHIFT, zholes_size);
208 
209 	/*
210 	 * map whole physical memory to virtual memory (identity mapping)
211 	 */
212 
213         pg_dir = swapper_pg_dir;
214 
215         for (i = 0 ; i < PTRS_PER_PGD ; i++,pg_dir++) {
216 
217                 if (pfn >= max_low_pfn) {
218                         pgd_clear(pg_dir);
219                         continue;
220                 }
221 
222 	        pm_dir = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE*4);
223                 pgd_populate(&init_mm, pg_dir, pm_dir);
224 
225                 for (j = 0 ; j < PTRS_PER_PMD ; j++,pm_dir++) {
226                         if (pfn >= max_low_pfn) {
227                                 pmd_clear(pm_dir);
228                                 continue;
229                         }
230 
231                         pt_dir = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
232                         pmd_populate_kernel(&init_mm, pm_dir, pt_dir);
233 
234                         for (k = 0 ; k < PTRS_PER_PTE ; k++,pt_dir++) {
235                                 pte = pfn_pte(pfn, PAGE_KERNEL);
236                                 if (pfn >= max_low_pfn) {
237                                         pte_clear(&init_mm, 0, &pte);
238                                         continue;
239                                 }
240                                 set_pte(pt_dir, pte);
241                                 pfn++;
242                         }
243                 }
244         }
245 
246 	S390_lowcore.kernel_asce = pgdir_k;
247 
248         /* enable virtual mapping in kernel mode */
249         __asm__ __volatile__("lctlg 1,1,%0\n\t"
250                              "lctlg 7,7,%0\n\t"
251                              "lctlg 13,13,%0\n\t"
252                              "ssm   %1"
253 			     : :"m" (pgdir_k), "m" (ssm_mask));
254 
255         local_flush_tlb();
256 
257         return;
258 }
259 #endif /* CONFIG_64BIT */
260 
261 void __init mem_init(void)
262 {
263 	unsigned long codesize, reservedpages, datasize, initsize;
264 
265         max_mapnr = num_physpages = max_low_pfn;
266         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
267 
268         /* clear the zero-page */
269         memset(empty_zero_page, 0, PAGE_SIZE);
270 
271 	/* this will put all low memory onto the freelists */
272 	totalram_pages += free_all_bootmem();
273 
274 	reservedpages = 0;
275 
276 	codesize =  (unsigned long) &_etext - (unsigned long) &_text;
277 	datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
278 	initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
279         printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, %ldk data, %ldk init)\n",
280                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
281                 max_mapnr << (PAGE_SHIFT-10),
282                 codesize >> 10,
283                 reservedpages << (PAGE_SHIFT-10),
284                 datasize >>10,
285                 initsize >> 10);
286 }
287 
288 void free_initmem(void)
289 {
290         unsigned long addr;
291 
292         addr = (unsigned long)(&__init_begin);
293         for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
294 		ClearPageReserved(virt_to_page(addr));
295 		set_page_count(virt_to_page(addr), 1);
296 		free_page(addr);
297 		totalram_pages++;
298         }
299         printk ("Freeing unused kernel memory: %ldk freed\n",
300 		((unsigned long)&__init_end - (unsigned long)&__init_begin) >> 10);
301 }
302 
303 #ifdef CONFIG_BLK_DEV_INITRD
304 void free_initrd_mem(unsigned long start, unsigned long end)
305 {
306         if (start < end)
307                 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
308         for (; start < end; start += PAGE_SIZE) {
309                 ClearPageReserved(virt_to_page(start));
310                 set_page_count(virt_to_page(start), 1);
311                 free_page(start);
312                 totalram_pages++;
313         }
314 }
315 #endif
316