1 /*
2  *  linux/arch/cris/mm/init.c
3  *
4  *  Copyright (C) 1995  Linus Torvalds
5  *  Copyright (C) 2000,2001  Axis Communications AB
6  *
7  *  Authors:  Bjorn Wesen (bjornw@axis.com)
8  *
9  *  $Log: init.c,v $
10  *  Revision 1.38  2003/04/01 14:12:08  starvik
11  *  Added loglevel for lots of printks
12  *
13  *  Revision 1.37  2003/01/22 06:54:47  starvik
14  *  Fixed warnings issued by GCC 3.2.1
15  *
16  *  Revision 1.36  2003/01/09 17:59:55  starvik
17  *  Added init_ioremap to initcalls
18  *
19  *  Revision 1.35  2002/05/17 05:33:59  starvik
20  *  Limit cache flush range to the size of the cache
21  *
22  *  Revision 1.34  2002/04/22 11:48:51  johana
23  *  Added KERN_INFO (2.4.19-pre7)
24  *
25  *  Revision 1.33  2002/03/19 15:22:17  bjornw
26  *  Added flush_etrax_cache
27  *
28  *  Revision 1.32  2002/03/15 17:09:31  bjornw
29  *  Added prepare_rx_descriptor as a workaround for a bug
30  *
31  *  Revision 1.31  2001/11/13 16:22:00  bjornw
32  *  Skip calculating totalram and sharedram in si_meminfo
33  *
34  *  Revision 1.30  2001/11/12 19:02:10  pkj
35  *  Fixed compiler warnings.
36  *
37  *  Revision 1.29  2001/07/25 16:09:50  bjornw
38  *  val->sharedram will stay 0
39  *
40  *  Revision 1.28  2001/06/28 16:30:17  bjornw
41  *  Oops. This needs to wait until 2.4.6 is merged
42  *
43  *  Revision 1.27  2001/06/28 14:04:07  bjornw
44  *  Fill in sharedram
45  *
46  *  Revision 1.26  2001/06/18 06:36:02  hp
47  *  Enable free_initmem of __init-type pages
48  *
49  *  Revision 1.25  2001/06/13 00:02:23  bjornw
50  *  Use a separate variable to store the current pgd to avoid races in schedule
51  *
52  *  Revision 1.24  2001/05/15 00:52:20  hp
53  *  Only map segment 0xa as seg if CONFIG_JULIETTE
54  *
55  *  Revision 1.23  2001/04/04 14:35:40  bjornw
56  *  * Removed get_pte_slow and friends (2.4.3 change)
57  *  * Removed bad_pmd handling (2.4.3 change)
58  *
59  *  Revision 1.22  2001/04/04 13:38:04  matsfg
60  *  Moved ioremap to a separate function instead
61  *
62  *  Revision 1.21  2001/03/27 09:28:33  bjornw
63  *  ioremap used too early - lets try it in mem_init instead
64  *
65  *  Revision 1.20  2001/03/23 07:39:21  starvik
66  *  Corrected according to review remarks
67  *
68  *  Revision 1.19  2001/03/15 14:25:17  bjornw
69  *  More general shadow registers and ioremaped addresses for external I/O
70  *
71  *  Revision 1.18  2001/02/23 12:46:44  bjornw
72  *  * 0xc was not CSE1; 0x8 is, same as uncached flash, so we move the uncached
73  *    flash during CRIS_LOW_MAP from 0xe to 0x8 so both the flash and the I/O
74  *    is mapped straight over (for !CRIS_LOW_MAP the uncached flash is still 0xe)
75  *
76  *  Revision 1.17  2001/02/22 15:05:21  bjornw
77  *  Map 0x9 straight over during LOW_MAP to allow for memory mapped LEDs
78  *
79  *  Revision 1.16  2001/02/22 15:02:35  bjornw
80  *  Map 0xc straight over during LOW_MAP to allow for memory mapped I/O
81  *
82  *  Revision 1.15  2001/01/10 21:12:10  bjornw
83  *  loops_per_sec -> loops_per_jiffy
84  *
85  *  Revision 1.14  2000/11/22 16:23:20  bjornw
86  *  Initialize totalhigh counters to 0 to make /proc/meminfo look nice.
87  *
88  *  Revision 1.13  2000/11/21 16:37:51  bjornw
89  *  Temporarily disable initmem freeing
90  *
91  *  Revision 1.12  2000/11/21 13:55:07  bjornw
92  *  Use CONFIG_CRIS_LOW_MAP for the low VM map instead of explicit CPU type
93  *
94  *  Revision 1.11  2000/10/06 12:38:22  bjornw
95  *  Cast empty_bad_page correctly (should really be of * type from the start..
96  *
97  *  Revision 1.10  2000/10/04 16:53:57  bjornw
98  *  Fix memory-map due to LX features
99  *
100  *  Revision 1.9  2000/09/13 15:47:49  bjornw
101  *  Wrong count in reserved-pages loop
102  *
103  *  Revision 1.8  2000/09/13 14:35:10  bjornw
104  *  2.4.0-test8 added a new arg to free_area_init_node
105  *
106  *  Revision 1.7  2000/08/17 15:35:55  bjornw
107  *  2.4.0-test6 removed MAP_NR and inserted virt_to_page
108  *
109  *
110  */
111 
112 #include <linux/config.h>
113 #include <linux/signal.h>
114 #include <linux/sched.h>
115 #include <linux/kernel.h>
116 #include <linux/errno.h>
117 #include <linux/string.h>
118 #include <linux/types.h>
119 #include <linux/ptrace.h>
120 #include <linux/mman.h>
121 #include <linux/mm.h>
122 #include <linux/swap.h>
123 #include <linux/smp.h>
124 #include <linux/bootmem.h>
125 #include <linux/init.h>
126 
127 #include <asm/system.h>
128 #include <asm/segment.h>
129 #include <asm/pgalloc.h>
130 #include <asm/pgtable.h>
131 #include <asm/dma.h>
132 #include <asm/svinto.h>
133 #include <asm/io.h>
134 #include <asm/mmu_context.h>
135 
136 static unsigned long totalram_pages;
137 
138 struct pgtable_cache_struct quicklists;  /* see asm/pgalloc.h */
139 
140 const char bad_pmd_string[] = "Bad pmd in pte_alloc: %08lx\n";
141 
142 extern void die_if_kernel(char *,struct pt_regs *,long);
143 extern void show_net_buffers(void);
144 extern void tlb_init(void);
145 
146 
147 unsigned long empty_zero_page;
148 
149 /* trim the page-table cache if necessary */
150 
151 int
do_check_pgt_cache(int low,int high)152 do_check_pgt_cache(int low, int high)
153 {
154         int freed = 0;
155 
156         if(pgtable_cache_size > high) {
157                 do {
158                         if(pgd_quicklist) {
159                                 free_pgd_slow(get_pgd_fast());
160                                 freed++;
161                         }
162                         if(pmd_quicklist) {
163                                 pmd_free_slow(pmd_alloc_one_fast(NULL, 0));
164                                 freed++;
165                         }
166                         if(pte_quicklist) {
167                                 pte_free_slow(pte_alloc_one_fast(NULL, 0));
168 				freed++;
169                         }
170                 } while(pgtable_cache_size > low);
171         }
172         return freed;
173 }
174 
175 void
show_mem(void)176 show_mem(void)
177 {
178 	int i,free = 0,total = 0,cached = 0, reserved = 0, nonshared = 0;
179 	int shared = 0;
180 
181 	printk("\nMem-info:\n");
182 	show_free_areas();
183 	printk("Free swap:       %6dkB\n",nr_swap_pages<<(PAGE_SHIFT-10));
184 	i = max_mapnr;
185 	while (i-- > 0) {
186 		total++;
187 		if (PageReserved(mem_map+i))
188 			reserved++;
189 		else if (PageSwapCache(mem_map+i))
190 			cached++;
191 		else if (!page_count(mem_map+i))
192 			free++;
193 		else if (page_count(mem_map+i) == 1)
194 			nonshared++;
195 		else
196 			shared += page_count(mem_map+i) - 1;
197 	}
198 	printk("%d pages of RAM\n",total);
199 	printk("%d free pages\n",free);
200 	printk("%d reserved pages\n",reserved);
201 	printk("%d pages nonshared\n",nonshared);
202 	printk("%d pages shared\n",shared);
203 	printk("%d pages swap cached\n",cached);
204 	printk("%ld pages in page table cache\n",pgtable_cache_size);
205 	show_buffers();
206 }
207 
208 /*
209  * The kernel is already mapped with a kernel segment at kseg_c so
210  * we don't need to map it with a page table. However head.S also
211  * temporarily mapped it at kseg_4 so we should set up the ksegs again,
212  * clear the TLB and do some other paging setup stuff.
213  */
214 
215 void __init
paging_init(void)216 paging_init(void)
217 {
218 	int i;
219 	unsigned long zones_size[MAX_NR_ZONES];
220 
221 	printk(KERN_INFO "Setting up paging and the MMU.\n");
222 
223 	/* clear out the init_mm.pgd that will contain the kernel's mappings */
224 
225 	for(i = 0; i < PTRS_PER_PGD; i++)
226 		swapper_pg_dir[i] = __pgd(0);
227 
228 	/* make sure the current pgd table points to something sane
229 	 * (even if it is most probably not used until the next
230 	 *  switch_mm)
231 	 */
232 
233 	current_pgd = init_mm.pgd;
234 
235 	/* initialise the TLB (tlb.c) */
236 
237 	tlb_init();
238 
239 	/* see README.mm for details on the KSEG setup */
240 
241 #ifndef CONFIG_CRIS_LOW_MAP
242 	/* This code is for the corrected Etrax-100 LX version 2... */
243 
244 #define CACHED_BOOTROM (KSEG_A | 0x08000000UL)
245 
246 	*R_MMU_KSEG = ( IO_STATE(R_MMU_KSEG, seg_f, seg  ) | /* cached flash */
247 			IO_STATE(R_MMU_KSEG, seg_e, seg  ) | /* uncached flash */
248 			IO_STATE(R_MMU_KSEG, seg_d, page ) | /* vmalloc area */
249 			IO_STATE(R_MMU_KSEG, seg_c, seg  ) | /* kernel area */
250 			IO_STATE(R_MMU_KSEG, seg_b, seg  ) | /* kernel reg area */
251 			IO_STATE(R_MMU_KSEG, seg_a, seg  ) | /* bootrom/regs cached */
252 			IO_STATE(R_MMU_KSEG, seg_9, page ) | /* user area */
253 			IO_STATE(R_MMU_KSEG, seg_8, page ) |
254 			IO_STATE(R_MMU_KSEG, seg_7, page ) |
255 			IO_STATE(R_MMU_KSEG, seg_6, page ) |
256 			IO_STATE(R_MMU_KSEG, seg_5, page ) |
257 			IO_STATE(R_MMU_KSEG, seg_4, page ) |
258 			IO_STATE(R_MMU_KSEG, seg_3, page ) |
259 			IO_STATE(R_MMU_KSEG, seg_2, page ) |
260 			IO_STATE(R_MMU_KSEG, seg_1, page ) |
261 			IO_STATE(R_MMU_KSEG, seg_0, page ) );
262 
263 	*R_MMU_KBASE_HI = ( IO_FIELD(R_MMU_KBASE_HI, base_f, 0x0 ) |
264 			    IO_FIELD(R_MMU_KBASE_HI, base_e, 0x8 ) |
265 			    IO_FIELD(R_MMU_KBASE_HI, base_d, 0x0 ) |
266 			    IO_FIELD(R_MMU_KBASE_HI, base_c, 0x4 ) |
267 			    IO_FIELD(R_MMU_KBASE_HI, base_b, 0xb ) |
268 			    IO_FIELD(R_MMU_KBASE_HI, base_a, 0x3 ) |
269 			    IO_FIELD(R_MMU_KBASE_HI, base_9, 0x0 ) |
270 			    IO_FIELD(R_MMU_KBASE_HI, base_8, 0x0 ) );
271 
272 	*R_MMU_KBASE_LO = ( IO_FIELD(R_MMU_KBASE_LO, base_7, 0x0 ) |
273 			    IO_FIELD(R_MMU_KBASE_LO, base_6, 0x0 ) |
274 			    IO_FIELD(R_MMU_KBASE_LO, base_5, 0x0 ) |
275 			    IO_FIELD(R_MMU_KBASE_LO, base_4, 0x0 ) |
276 			    IO_FIELD(R_MMU_KBASE_LO, base_3, 0x0 ) |
277 			    IO_FIELD(R_MMU_KBASE_LO, base_2, 0x0 ) |
278 			    IO_FIELD(R_MMU_KBASE_LO, base_1, 0x0 ) |
279 			    IO_FIELD(R_MMU_KBASE_LO, base_0, 0x0 ) );
280 #else
281 	/* Etrax-100 LX version 1 has a bug so that we cannot map anything
282 	 * across the 0x80000000 boundary, so we need to shrink the user-virtual
283 	 * area to 0x50000000 instead of 0xb0000000 and map things slightly
284 	 * different. The unused areas are marked as paged so that we can catch
285 	 * freak kernel accesses there.
286 	 *
287 	 * The ARTPEC chip is mapped at 0xa so we pass that segment straight
288 	 * through. We cannot vremap it because the vmalloc area is below 0x8
289 	 * and Juliette needs an uncached area above 0x8.
290 	 *
291 	 * Same thing with 0xc and 0x9, which is memory-mapped I/O on some boards.
292 	 * We map them straight over in LOW_MAP, but use vremap in LX version 2.
293 	 */
294 
295 #define CACHED_BOOTROM (KSEG_F | 0x08000000UL)
296 
297 	*R_MMU_KSEG = ( IO_STATE(R_MMU_KSEG, seg_f, seg  ) |  /* cached bootrom/regs */
298 			IO_STATE(R_MMU_KSEG, seg_e, page ) |
299 			IO_STATE(R_MMU_KSEG, seg_d, page ) |
300 			IO_STATE(R_MMU_KSEG, seg_c, page ) |
301 			IO_STATE(R_MMU_KSEG, seg_b, seg  ) |  /* kernel reg area */
302 #ifdef CONFIG_JULIETTE
303 			IO_STATE(R_MMU_KSEG, seg_a, seg  ) |  /* ARTPEC etc. */
304 #else
305 			IO_STATE(R_MMU_KSEG, seg_a, page ) |
306 #endif
307 			IO_STATE(R_MMU_KSEG, seg_9, seg  ) |  /* LED's on some boards */
308 			IO_STATE(R_MMU_KSEG, seg_8, seg  ) |  /* CSE0/1, flash and I/O */
309 			IO_STATE(R_MMU_KSEG, seg_7, page ) |  /* kernel vmalloc area */
310 			IO_STATE(R_MMU_KSEG, seg_6, seg  ) |  /* kernel DRAM area */
311 			IO_STATE(R_MMU_KSEG, seg_5, seg  ) |  /* cached flash */
312 			IO_STATE(R_MMU_KSEG, seg_4, page ) |  /* user area */
313 			IO_STATE(R_MMU_KSEG, seg_3, page ) |  /* user area */
314 			IO_STATE(R_MMU_KSEG, seg_2, page ) |  /* user area */
315 			IO_STATE(R_MMU_KSEG, seg_1, page ) |  /* user area */
316 			IO_STATE(R_MMU_KSEG, seg_0, page ) ); /* user area */
317 
318 	*R_MMU_KBASE_HI = ( IO_FIELD(R_MMU_KBASE_HI, base_f, 0x3 ) |
319 			    IO_FIELD(R_MMU_KBASE_HI, base_e, 0x0 ) |
320 			    IO_FIELD(R_MMU_KBASE_HI, base_d, 0x0 ) |
321 			    IO_FIELD(R_MMU_KBASE_HI, base_c, 0x0 ) |
322 			    IO_FIELD(R_MMU_KBASE_HI, base_b, 0xb ) |
323 #ifdef CONFIG_JULIETTE
324 			    IO_FIELD(R_MMU_KBASE_HI, base_a, 0xa ) |
325 #else
326 			    IO_FIELD(R_MMU_KBASE_HI, base_a, 0x0 ) |
327 #endif
328 			    IO_FIELD(R_MMU_KBASE_HI, base_9, 0x9 ) |
329 			    IO_FIELD(R_MMU_KBASE_HI, base_8, 0x8 ) );
330 
331 	*R_MMU_KBASE_LO = ( IO_FIELD(R_MMU_KBASE_LO, base_7, 0x0 ) |
332 			    IO_FIELD(R_MMU_KBASE_LO, base_6, 0x4 ) |
333 			    IO_FIELD(R_MMU_KBASE_LO, base_5, 0x0 ) |
334 			    IO_FIELD(R_MMU_KBASE_LO, base_4, 0x0 ) |
335 			    IO_FIELD(R_MMU_KBASE_LO, base_3, 0x0 ) |
336 			    IO_FIELD(R_MMU_KBASE_LO, base_2, 0x0 ) |
337 			    IO_FIELD(R_MMU_KBASE_LO, base_1, 0x0 ) |
338 			    IO_FIELD(R_MMU_KBASE_LO, base_0, 0x0 ) );
339 #endif
340 
341 	*R_MMU_CONTEXT = ( IO_FIELD(R_MMU_CONTEXT, page_id, 0 ) );
342 
343 	/* The MMU has been enabled ever since head.S but just to make
344 	 * it totally obvious we do it here as well.
345 	 */
346 
347 	*R_MMU_CTRL = ( IO_STATE(R_MMU_CTRL, inv_excp, enable ) |
348 			IO_STATE(R_MMU_CTRL, acc_excp, enable ) |
349 			IO_STATE(R_MMU_CTRL, we_excp,  enable ) );
350 
351 	*R_MMU_ENABLE = IO_STATE(R_MMU_ENABLE, mmu_enable, enable);
352 
353 	/*
354 	 * initialize the bad page table and bad page to point
355 	 * to a couple of allocated pages
356 	 */
357 
358 	empty_zero_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
359 	memset((void *)empty_zero_page, 0, PAGE_SIZE);
360 
361 	/* All pages are DMA'able in Etrax, so put all in the DMA'able zone */
362 
363 	zones_size[0] = ((unsigned long)high_memory - PAGE_OFFSET) >> PAGE_SHIFT;
364 
365 	for (i = 1; i < MAX_NR_ZONES; i++)
366 		zones_size[i] = 0;
367 
368 	/* Use free_area_init_node instead of free_area_init, because the former
369 	 * is designed for systems where the DRAM starts at an address substantially
370 	 * higher than 0, like us (we start at PAGE_OFFSET). This saves space in the
371 	 * mem_map page array.
372 	 */
373 
374 	free_area_init_node(0, 0, 0, zones_size, PAGE_OFFSET, 0);
375 
376 }
377 
378 extern unsigned long loops_per_jiffy; /* init/main.c */
379 unsigned long loops_per_usec;
380 
381 extern char _stext, _edata, _etext;
382 extern char __init_begin, __init_end;
383 
384 void __init
mem_init(void)385 mem_init(void)
386 {
387 	int codesize, reservedpages, datasize, initsize;
388 	unsigned long tmp;
389 
390 	if(!mem_map)
391 		BUG();
392 
393 	/* max/min_low_pfn was set by setup.c
394 	 * now we just copy it to some other necessary places...
395 	 *
396 	 * high_memory was also set in setup.c
397 	 */
398 
399 	max_mapnr = num_physpages = max_low_pfn - min_low_pfn;
400 
401 	/* this will put all memory onto the freelists */
402         totalram_pages = free_all_bootmem();
403 
404 	reservedpages = 0;
405 	for (tmp = 0; tmp < max_mapnr; tmp++) {
406 		/*
407                  * Only count reserved RAM pages
408                  */
409 		if (PageReserved(mem_map + tmp))
410 			reservedpages++;
411 	}
412 
413 	codesize =  (unsigned long) &_etext - (unsigned long) &_stext;
414         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
415         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
416 
417         printk(KERN_INFO
418 	       "Memory: %luk/%luk available (%dk kernel code, %dk reserved, %dk data, "
419 	       "%dk init)\n" ,
420 	       (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
421 	       max_mapnr << (PAGE_SHIFT-10),
422 	       codesize >> 10,
423 	       reservedpages << (PAGE_SHIFT-10),
424 	       datasize >> 10,
425 	       initsize >> 10
426                );
427 
428 	/* HACK alert - calculate a loops_per_usec for asm/delay.h here
429 	 * since this is called just after calibrate_delay in init/main.c
430 	 * but before places which use udelay. cannot be in time.c since
431 	 * that is called _before_ calibrate_delay
432 	 */
433 
434 	loops_per_usec = (loops_per_jiffy * HZ) / 1000000;
435 
436 	return;
437 }
438 
439 /* Initialize remaps of some I/O-ports. It is important that this
440  * is called before any driver is initialized.
441  */
442 
443 static int
init_ioremap(void)444 __init init_ioremap(void)
445 {
446 
447 	/* Give the external I/O-port addresses their values */
448 
449 #ifdef CONFIG_CRIS_LOW_MAP
450 	/* Simply a linear map (see the KSEG map above in paging_init) */
451 	port_cse1_addr = (volatile unsigned long *)(MEM_CSE1_START |
452 	                                            MEM_NON_CACHEABLE);
453 	port_csp0_addr = (volatile unsigned long *)(MEM_CSP0_START |
454 	                                            MEM_NON_CACHEABLE);
455 	port_csp4_addr = (volatile unsigned long *)(MEM_CSP4_START |
456 	                                            MEM_NON_CACHEABLE);
457 #else
458 	/* Note that nothing blows up just because we do this remapping
459 	 * it's ok even if the ports are not used or connected
460 	 * to anything (or connected to a non-I/O thing) */
461 	port_cse1_addr = (volatile unsigned long *)
462 	ioremap((unsigned long)(MEM_CSE1_START | MEM_NON_CACHEABLE), 16);
463 	port_csp0_addr = (volatile unsigned long *)
464 	ioremap((unsigned long)(MEM_CSP0_START | MEM_NON_CACHEABLE), 16);
465 	port_csp4_addr = (volatile unsigned long *)
466 	ioremap((unsigned long)(MEM_CSP4_START | MEM_NON_CACHEABLE), 16);
467 #endif
468 	return 0;
469 }
470 
471 __initcall(init_ioremap);
472 
473 /* Helper function for the two below */
474 
475 static inline void
flush_etrax_cacherange(void * startadr,int length)476 flush_etrax_cacherange(void *startadr, int length)
477 {
478 	/* CACHED_BOOTROM is mapped to the boot-rom area (cached) which
479 	 * we can use to get fast dummy-reads of cachelines
480 	 */
481 
482 	volatile short *flushadr = (volatile short *)(((unsigned long)startadr & ~PAGE_MASK) |
483 						      CACHED_BOOTROM);
484 
485 	length = length > 8192 ? 8192 : length;  /* No need to flush more than cache size */
486 
487 	while(length > 0) {
488 		*flushadr; /* dummy read to flush */
489 		flushadr += (32/sizeof(short));  /* a cacheline is 32 bytes */
490 		length -= 32;
491 	}
492 }
493 
494 /* Due to a bug in Etrax100(LX) all versions, receiving DMA buffers
495  * will occationally corrupt certain CPU writes if the DMA buffers
496  * happen to be hot in the cache.
497  *
498  * As a workaround, we have to flush the relevant parts of the cache
499  * before (re) inserting any receiving descriptor into the DMA HW.
500  */
501 
502 void
prepare_rx_descriptor(struct etrax_dma_descr * desc)503 prepare_rx_descriptor(struct etrax_dma_descr *desc)
504 {
505 	flush_etrax_cacherange((void *)desc->buf, desc->sw_len ? desc->sw_len : 65536);
506 }
507 
508 /* Do the same thing but flush the entire cache */
509 
510 void
flush_etrax_cache(void)511 flush_etrax_cache(void)
512 {
513 	flush_etrax_cacherange(0, 8192);
514 }
515 
516 /* free the pages occupied by initialization code */
517 
518 void
free_initmem(void)519 free_initmem(void)
520 {
521         unsigned long addr;
522 
523         addr = (unsigned long)(&__init_begin);
524         for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
525                 ClearPageReserved(virt_to_page(addr));
526                 set_page_count(virt_to_page(addr), 1);
527                 free_page(addr);
528                 totalram_pages++;
529         }
530         printk (KERN_INFO "Freeing unused kernel memory: %luk freed\n",
531 		(unsigned long)((&__init_end - &__init_begin) >> 10));
532 }
533 
534 void
si_meminfo(struct sysinfo * val)535 si_meminfo(struct sysinfo *val)
536 {
537         val->totalram = totalram_pages;
538         val->sharedram = 0;
539         val->freeram = nr_free_pages();
540         val->bufferram = atomic_read(&buffermem_pages);
541         val->totalhigh = 0;
542         val->freehigh = 0;
543         val->mem_unit = PAGE_SIZE;
544 }
545