[linux-2.6-block.git] / arch / mips / dec / prom / memory.c

/*
 * memory.c: memory initialisation code.
 *
 * Copyright (C) 1998 Harald Koerfgen, Frieder Streffer and Paul M. Antoine
 * Copyright (C) 2000, 2002  Maciej W. Rozycki
 */
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/bootmem.h>
#include <linux/types.h>

#include <asm/addrspace.h>
#include <asm/bootinfo.h>
#include <asm/dec/machtype.h>
#include <asm/dec/prom.h>
#include <asm/page.h>
#include <asm/sections.h>


volatile unsigned long mem_err;		/* So we know an error occurred */

/*
 * Probe memory in 4MB chunks, waiting for an error to tell us we've fallen
 * off the end of real memory.  Only suitable for the 2100/3100's (PMAX).
 */

#define CHUNK_SIZE 0x400000

static inline void pmax_setup_memory_region(void)
{
	volatile unsigned char *memory_page, dummy;
	char old_handler[0x80];
	extern char genexcept_early;

	/* Install exception handler */
	memcpy(&old_handler, (void *)(CKSEG0 + 0x80), 0x80);
	memcpy((void *)(CKSEG0 + 0x80), &genexcept_early, 0x80);

	/* read unmapped and uncached (KSEG1)
	 * DECstations have at least 4MB RAM
	 * Assume less than 480MB of RAM, as this is max for 5000/2xx
	 * FIXME this should be replaced by the first free page!
	 */
	for (memory_page = (unsigned char *)CKSEG1 + CHUNK_SIZE;
	     mem_err == 0 && memory_page < (unsigned char *)CKSEG1 + 0x1e00000;
	     memory_page += CHUNK_SIZE) {
		dummy = *memory_page;
	}
	memcpy((void *)(CKSEG0 + 0x80), &old_handler, 0x80);

	add_memory_region(0, (unsigned long)memory_page - CKSEG1 - CHUNK_SIZE,
			  BOOT_MEM_RAM);
}

/*
 * Use the REX prom calls to get hold of the memory bitmap, and thence
 * determine memory size.
 */
static inline void rex_setup_memory_region(void)
{
	int i, bitmap_size;
	unsigned long mem_start = 0, mem_size = 0;
	memmap *bm;

	/* some free 64k */
	bm = (memmap *)CKSEG0ADDR(0x28000);

	bitmap_size = rex_getbitmap(bm);

	for (i = 0; i < bitmap_size; i++) {
		/* FIXME: very simplistically only add full sets of pages */
		if (bm->bitmap[i] == 0xff)
			mem_size += (8 * bm->pagesize);
		else if (!mem_size)
			mem_start += (8 * bm->pagesize);
		else {
			add_memory_region(mem_start, mem_size, BOOT_MEM_RAM);
			mem_start += mem_size + (8 * bm->pagesize);
			mem_size = 0;
		}
	}
	if (mem_size)
		add_memory_region(mem_start, mem_size, BOOT_MEM_RAM);
}

void __init prom_meminit(u32 magic)
{
	if (!prom_is_rex(magic))
		pmax_setup_memory_region();
	else
		rex_setup_memory_region();
}

void __init prom_free_prom_memory(void)
{
	unsigned long end;

	/*
	 * Free everything below the kernel itself but leave
	 * the first page reserved for the exception handlers.
	 */

#if IS_ENABLED(CONFIG_DECLANCE)
	/*
	 * Leave 128 KB reserved for Lance memory for
	 * IOASIC DECstations.
	 *
	 * XXX: save this address for use in dec_lance.c?
	 */
	if (IOASIC)
		end = __pa(&_text) - 0x00020000;
	else
#endif
		end = __pa(&_text);

	free_init_pages("unused PROM memory", PAGE_SIZE, end);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* memory.c: memory initialisation code.
	3	*
	4	* Copyright (C) 1998 Harald Koerfgen, Frieder Streffer and Paul M. Antoine
	5	* Copyright (C) 2000, 2002 Maciej W. Rozycki
	6	*/
1da177e4 LT	7	#include <linux/init.h>
	8	#include <linux/kernel.h>
	9	#include <linux/mm.h>
	10	#include <linux/bootmem.h>
	11	#include <linux/types.h>
	12
	13	#include <asm/addrspace.h>
	14	#include <asm/bootinfo.h>
	15	#include <asm/dec/machtype.h>
	16	#include <asm/dec/prom.h>
	17	#include <asm/page.h>
	18	#include <asm/sections.h>
	19
	20
982f6ffe	21	volatile unsigned long mem_err; /* So we know an error occurred */
1da177e4 LT	22
	23	/*
	24	* Probe memory in 4MB chunks, waiting for an error to tell us we've fallen
07217d75	25	* off the end of real memory. Only suitable for the 2100/3100's (PMAX).
1da177e4 LT	26	*/
	27
	28	#define CHUNK_SIZE 0x400000
	29
	30	static inline void pmax_setup_memory_region(void)
	31	{
	32	volatile unsigned char *memory_page, dummy;
	33	char old_handler[0x80];
	34	extern char genexcept_early;
	35
	36	/* Install exception handler */
3bd4c902 MR	37	memcpy(&old_handler, (void *)(CKSEG0 + 0x80), 0x80);
3bd4c902 MR	38	memcpy((void *)(CKSEG0 + 0x80), &genexcept_early, 0x80);
1da177e4 LT	39
	40	/* read unmapped and uncached (KSEG1)
	41	* DECstations have at least 4MB RAM
	42	* Assume less than 480MB of RAM, as this is max for 5000/2xx
	43	* FIXME this should be replaced by the first free page!
	44	*/
3bd4c902 MR	45	for (memory_page = (unsigned char *)CKSEG1 + CHUNK_SIZE;
3bd4c902 MR	46	mem_err == 0 && memory_page < (unsigned char *)CKSEG1 + 0x1e00000;
a3dddd56	47	memory_page += CHUNK_SIZE) {
1da177e4 LT	48	dummy = *memory_page;
1da177e4 LT	49	}
3bd4c902	50	memcpy((void *)(CKSEG0 + 0x80), &old_handler, 0x80);
1da177e4	51
3bd4c902	52	add_memory_region(0, (unsigned long)memory_page - CKSEG1 - CHUNK_SIZE,
1da177e4 LT	53	BOOT_MEM_RAM);
	54	}
	55
	56	/*
	57	* Use the REX prom calls to get hold of the memory bitmap, and thence
	58	* determine memory size.
	59	*/
	60	static inline void rex_setup_memory_region(void)
	61	{
	62	int i, bitmap_size;
	63	unsigned long mem_start = 0, mem_size = 0;
	64	memmap *bm;
	65
	66	/* some free 64k */
3bd4c902	67	bm = (memmap *)CKSEG0ADDR(0x28000);
1da177e4 LT	68
	69	bitmap_size = rex_getbitmap(bm);
	70
	71	for (i = 0; i < bitmap_size; i++) {
	72	/* FIXME: very simplistically only add full sets of pages */
	73	if (bm->bitmap[i] == 0xff)
	74	mem_size += (8 * bm->pagesize);
	75	else if (!mem_size)
	76	mem_start += (8 * bm->pagesize);
	77	else {
	78	add_memory_region(mem_start, mem_size, BOOT_MEM_RAM);
	79	mem_start += mem_size + (8 * bm->pagesize);
	80	mem_size = 0;
	81	}
	82	}
	83	if (mem_size)
	84	add_memory_region(mem_start, mem_size, BOOT_MEM_RAM);
	85	}
	86
	87	void __init prom_meminit(u32 magic)
	88	{
	89	if (!prom_is_rex(magic))
	90	pmax_setup_memory_region();
	91	else
	92	rex_setup_memory_region();
	93	}
	94
c44e8d5e	95	void __init prom_free_prom_memory(void)
1da177e4	96	{
c44e8d5e	97	unsigned long end;
1da177e4 LT	98
	99	/*
	100	* Free everything below the kernel itself but leave
	101	* the first page reserved for the exception handlers.
	102	*/
	103
baf69e27	104	#if IS_ENABLED(CONFIG_DECLANCE)
1da177e4 LT	105	/*
	106	* Leave 128 KB reserved for Lance memory for
	107	* IOASIC DECstations.
	108	*
	109	* XXX: save this address for use in dec_lance.c?
	110	*/
	111	if (IOASIC)
	112	end = __pa(&_text) - 0x00020000;
	113	else
	114	#endif
	115	end = __pa(&_text);
	116
c44e8d5e	117	free_init_pages("unused PROM memory", PAGE_SIZE, end);
1da177e4	118	}