prom_init.c

linux 内核源代码

/*
 * Procedures for interfacing to Open Firmware.
 *
 * Paul Mackerras	August 1996.
 * Copyright (C) 1996-2005 Paul Mackerras.
 * 
 *  Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
 *    {engebret|bergner}@us.ibm.com 
 *
 *      This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 */

#undef DEBUG_PROM

#include <stdarg.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/threads.h>
#include <linux/spinlock.h>
#include <linux/types.h>
#include <linux/pci.h>
#include <linux/proc_fs.h>
#include <linux/stringify.h>
#include <linux/delay.h>
#include <linux/initrd.h>
#include <linux/bitops.h>
#include <asm/prom.h>
#include <asm/rtas.h>
#include <asm/page.h>
#include <asm/processor.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <asm/smp.h>
#include <asm/system.h>
#include <asm/mmu.h>
#include <asm/pgtable.h>
#include <asm/pci.h>
#include <asm/iommu.h>
#include <asm/btext.h>
#include <asm/sections.h>
#include <asm/machdep.h>

#ifdef CONFIG_LOGO_LINUX_CLUT224
#include <linux/linux_logo.h>
extern const struct linux_logo logo_linux_clut224;
#endif

/*
 * Properties whose value is longer than this get excluded from our
 * copy of the device tree. This value does need to be big enough to
 * ensure that we don't lose things like the interrupt-map property
 * on a PCI-PCI bridge.
 */
#define MAX_PROPERTY_LENGTH	(1UL * 1024 * 1024)

/*
 * Eventually bump that one up
 */
#define DEVTREE_CHUNK_SIZE	0x100000

/*
 * This is the size of the local memory reserve map that gets copied
 * into the boot params passed to the kernel. That size is totally
 * flexible as the kernel just reads the list until it encounters an
 * entry with size 0, so it can be changed without breaking binary
 * compatibility
 */
#define MEM_RESERVE_MAP_SIZE	8

/*
 * prom_init() is called very early on, before the kernel text
 * and data have been mapped to KERNELBASE.  At this point the code
 * is running at whatever address it has been loaded at.
 * On ppc32 we compile with -mrelocatable, which means that references
 * to extern and static variables get relocated automatically.
 * On ppc64 we have to relocate the references explicitly with
 * RELOC.  (Note that strings count as static variables.)
 *
 * Because OF may have mapped I/O devices into the area starting at
 * KERNELBASE, particularly on CHRP machines, we can't safely call
 * OF once the kernel has been mapped to KERNELBASE.  Therefore all
 * OF calls must be done within prom_init().
 *
 * ADDR is used in calls to call_prom.  The 4th and following
 * arguments to call_prom should be 32-bit values.
 * On ppc64, 64 bit values are truncated to 32 bits (and
 * fortunately don't get interpreted as two arguments).
 */
#ifdef CONFIG_PPC64
#define RELOC(x)        (*PTRRELOC(&(x)))
#define ADDR(x)		(u32) add_reloc_offset((unsigned long)(x))
#define OF_WORKAROUNDS	0
#else
#define RELOC(x)	(x)
#define ADDR(x)		(u32) (x)
#define OF_WORKAROUNDS	of_workarounds
int of_workarounds;
#endif

#define OF_WA_CLAIM	1	/* do phys/virt claim separately, then map */
#define OF_WA_LONGTRAIL	2	/* work around longtrail bugs */

#define PROM_BUG() do {						\
        prom_printf("kernel BUG at %s line 0x%x!\n",		\
		    RELOC(__FILE__), __LINE__);			\
        __asm__ __volatile__(".long " BUG_ILLEGAL_INSTR);	\
} while (0)

#ifdef DEBUG_PROM
#define prom_debug(x...)	prom_printf(x)
#else
#define prom_debug(x...)
#endif


typedef u32 prom_arg_t;

struct prom_args {
        u32 service;
        u32 nargs;
        u32 nret;
        prom_arg_t args[10];
};

struct prom_t {
	ihandle root;
	phandle chosen;
	int cpu;
	ihandle stdout;
	ihandle mmumap;
	ihandle memory;
};

struct mem_map_entry {
	u64	base;
	u64	size;
};

typedef u32 cell_t;

extern void __start(unsigned long r3, unsigned long r4, unsigned long r5);

#ifdef CONFIG_PPC64
extern int enter_prom(struct prom_args *args, unsigned long entry);
#else
static inline int enter_prom(struct prom_args *args, unsigned long entry)
{
	return ((int (*)(struct prom_args *))entry)(args);
}
#endif

extern void copy_and_flush(unsigned long dest, unsigned long src,
			   unsigned long size, unsigned long offset);

/* prom structure */
static struct prom_t __initdata prom;

static unsigned long prom_entry __initdata;

#define PROM_SCRATCH_SIZE 256

static char __initdata of_stdout_device[256];
static char __initdata prom_scratch[PROM_SCRATCH_SIZE];

static unsigned long __initdata dt_header_start;
static unsigned long __initdata dt_struct_start, dt_struct_end;
static unsigned long __initdata dt_string_start, dt_string_end;

static unsigned long __initdata prom_initrd_start, prom_initrd_end;

#ifdef CONFIG_PPC64
static int __initdata prom_iommu_force_on;
static int __initdata prom_iommu_off;
static unsigned long __initdata prom_tce_alloc_start;
static unsigned long __initdata prom_tce_alloc_end;
#endif

/* Platforms codes are now obsolete in the kernel. Now only used within this
 * file and ultimately gone too. Feel free to change them if you need, they
 * are not shared with anything outside of this file anymore
 */
#define PLATFORM_PSERIES	0x0100
#define PLATFORM_PSERIES_LPAR	0x0101
#define PLATFORM_LPAR		0x0001
#define PLATFORM_POWERMAC	0x0400
#define PLATFORM_GENERIC	0x0500

static int __initdata of_platform;

static char __initdata prom_cmd_line[COMMAND_LINE_SIZE];

static unsigned long __initdata alloc_top;
static unsigned long __initdata alloc_top_high;
static unsigned long __initdata alloc_bottom;
static unsigned long __initdata rmo_top;
static unsigned long __initdata ram_top;

static struct mem_map_entry __initdata mem_reserve_map[MEM_RESERVE_MAP_SIZE];
static int __initdata mem_reserve_cnt;

static cell_t __initdata regbuf[1024];


#define MAX_CPU_THREADS 2

/*
 * Error results ... some OF calls will return "-1" on error, some
 * will return 0, some will return either. To simplify, here are
 * macros to use with any ihandle or phandle return value to check if
 * it is valid
 */

#define PROM_ERROR		(-1u)
#define PHANDLE_VALID(p)	((p) != 0 && (p) != PROM_ERROR)
#define IHANDLE_VALID(i)	((i) != 0 && (i) != PROM_ERROR)


/* This is the one and *ONLY* place where we actually call open
 * firmware.
 */

static int __init call_prom(const char *service, int nargs, int nret, ...)
{
	int i;
	struct prom_args args;
	va_list list;

	args.service = ADDR(service);
	args.nargs = nargs;
	args.nret = nret;

	va_start(list, nret);
	for (i = 0; i < nargs; i++)
		args.args[i] = va_arg(list, prom_arg_t);
	va_end(list);

	for (i = 0; i < nret; i++)
		args.args[nargs+i] = 0;

	if (enter_prom(&args, RELOC(prom_entry)) < 0)
		return PROM_ERROR;

	return (nret > 0) ? args.args[nargs] : 0;
}

static int __init call_prom_ret(const char *service, int nargs, int nret,
				prom_arg_t *rets, ...)
{
	int i;
	struct prom_args args;
	va_list list;

	args.service = ADDR(service);
	args.nargs = nargs;
	args.nret = nret;

	va_start(list, rets);
	for (i = 0; i < nargs; i++)
		args.args[i] = va_arg(list, prom_arg_t);
	va_end(list);

	for (i = 0; i < nret; i++)
		args.args[nargs+i] = 0;

	if (enter_prom(&args, RELOC(prom_entry)) < 0)
		return PROM_ERROR;

	if (rets != NULL)
		for (i = 1; i < nret; ++i)
			rets[i-1] = args.args[nargs+i];

	return (nret > 0) ? args.args[nargs] : 0;
}


static void __init prom_print(const char *msg)
{
	const char *p, *q;
	struct prom_t *_prom = &RELOC(prom);

	if (_prom->stdout == 0)
		return;

	for (p = msg; *p != 0; p = q) {
		for (q = p; *q != 0 && *q != '\n'; ++q)
			;
		if (q > p)
			call_prom("write", 3, 1, _prom->stdout, p, q - p);
		if (*q == 0)
			break;
		++q;
		call_prom("write", 3, 1, _prom->stdout, ADDR("\r\n"), 2);
	}
}


static void __init prom_print_hex(unsigned long val)
{
	int i, nibbles = sizeof(val)*2;
	char buf[sizeof(val)*2+1];
	struct prom_t *_prom = &RELOC(prom);

	for (i = nibbles-1;  i >= 0;  i--) {
		buf[i] = (val & 0xf) + '0';
		if (buf[i] > '9')
			buf[i] += ('a'-'0'-10);
		val >>= 4;
	}
	buf[nibbles] = '\0';
	call_prom("write", 3, 1, _prom->stdout, buf, nibbles);
}


static void __init prom_printf(const char *format, ...)
{
	const char *p, *q, *s;
	va_list args;
	unsigned long v;
	struct prom_t *_prom = &RELOC(prom);

	va_start(args, format);
#ifdef CONFIG_PPC64
	format = PTRRELOC(format);
#endif
	for (p = format; *p != 0; p = q) {
		for (q = p; *q != 0 && *q != '\n' && *q != '%'; ++q)
			;
		if (q > p)
			call_prom("write", 3, 1, _prom->stdout, p, q - p);
		if (*q == 0)
			break;
		if (*q == '\n') {
			++q;
			call_prom("write", 3, 1, _prom->stdout,
				  ADDR("\r\n"), 2);
			continue;
		}
		++q;
		if (*q == 0)
			break;
		switch (*q) {
		case 's':
			++q;
			s = va_arg(args, const char *);
			prom_print(s);
			break;
		case 'x':
			++q;
			v = va_arg(args, unsigned long);
			prom_print_hex(v);
			break;
		}
	}
}


static unsigned int __init prom_claim(unsigned long virt, unsigned long size,
				unsigned long align)
{
	struct prom_t *_prom = &RELOC(prom);

	if (align == 0 && (OF_WORKAROUNDS & OF_WA_CLAIM)) {
		/*
		 * Old OF requires we claim physical and virtual separately
		 * and then map explicitly (assuming virtual mode)
		 */
		int ret;
		prom_arg_t result;

		ret = call_prom_ret("call-method", 5, 2, &result,
				    ADDR("claim"), _prom->memory,
				    align, size, virt);
		if (ret != 0 || result == -1)
			return -1;
		ret = call_prom_ret("call-method", 5, 2, &result,
				    ADDR("claim"), _prom->mmumap,
				    align, size, virt);
		if (ret != 0) {
			call_prom("call-method", 4, 1, ADDR("release"),
				  _prom->memory, size, virt);
			return -1;
		}
		/* the 0x12 is M (coherence) + PP == read/write */
		call_prom("call-method", 6, 1,
			  ADDR("map"), _prom->mmumap, 0x12, size, virt, virt);
		return virt;
	}
	return call_prom("claim", 3, 1, (prom_arg_t)virt, (prom_arg_t)size,
			 (prom_arg_t)align);
}

static void __init __attribute__((noreturn)) prom_panic(const char *reason)
{
#ifdef CONFIG_PPC64
	reason = PTRRELOC(reason);
#endif
	prom_print(reason);
	/* Do not call exit because it clears the screen on pmac
	 * it also causes some sort of double-fault on early pmacs */
	if (RELOC(of_platform) == PLATFORM_POWERMAC)
		asm("trap\n");

	/* ToDo: should put up an SRC here on p/iSeries */
	call_prom("exit", 0, 0);

	for (;;)			/* should never get here */
		;
}


static int __init prom_next_node(phandle *nodep)
{
	phandle node;

	if ((node = *nodep) != 0
	    && (*nodep = call_prom("child", 1, 1, node)) != 0)
		return 1;
	if ((*nodep = call_prom("peer", 1, 1, node)) != 0)
		return 1;
	for (;;) {
		if ((node = call_prom("parent", 1, 1, node)) == 0)
			return 0;
		if ((*nodep = call_prom("peer", 1, 1, node)) != 0)
			return 1;
	}
}

static int inline prom_getprop(phandle node, const char *pname,
			       void *value, size_t valuelen)
{
	return call_prom("getprop", 4, 1, node, ADDR(pname),
			 (u32)(unsigned long) value, (u32) valuelen);
}

static int inline prom_getproplen(phandle node, const char *pname)
{
	return call_prom("getproplen", 2, 1, node, ADDR(pname));
}

static void add_string(char **str, const char *q)
{
	char *p = *str;

	while (*q)
		*p++ = *q++;
	*p++ = ' ';
	*str = p;
}

static char *tohex(unsigned int x)
{
	static char digits[] = "0123456789abcdef";
	static char result[9];
	int i;

	result[8] = 0;
	i = 8;
	do {
		--i;
		result[i] = digits[x & 0xf];
		x >>= 4;
	} while (x != 0 && i > 0);
	return &result[i];
}