prom_init.c

Linux Kernel 2.6.9 for OMAP1710

/*
 * 
 *
 * Procedures for interfacing to Open Firmware.
 *
 * Paul Mackerras	August 1996.
 * Copyright (C) 1996 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/config.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/version.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 <asm/prom.h>
#include <asm/rtas.h>
#include <asm/abs_addr.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/bitops.h>
#include <asm/naca.h>
#include <asm/pci.h>
#include <asm/iommu.h>
#include <asm/bootinfo.h>
#include <asm/ppcdebug.h>
#include <asm/btext.h>
#include <asm/sections.h>
#include <asm/machdep.h>
#include "open_pic.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, so
 * references to extern and static variables must be relocated
 * explicitly.  The procedure reloc_offset() returns the address
 * we're currently running at minus the address we were linked at.
 * (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 should be done within prom_init(), and prom_init()
 * and all routines called within it must be careful to relocate
 * references as necessary.
 *
 * Note that the bss is cleared *after* prom_init runs, so we have
 * to make sure that any static or extern variables it accesses
 * are put in the data segment.
 */


#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];
        prom_arg_t *rets;     /* Pointer to return values in args[16]. */
};

struct prom_t {
	unsigned long entry;
	ihandle root;
	ihandle chosen;
	int cpu;
	ihandle stdout;
	ihandle disp_node;
	struct prom_args args;
	unsigned long version;
	unsigned long root_size_cells;
	unsigned long root_addr_cells;
};

struct pci_reg_property {
	struct pci_address addr;
	u32 size_hi;
	u32 size_lo;
};

struct mem_map_entry {
	u64	base;
	u64	size;
};

typedef u32 cell_t;

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

extern unsigned long reloc_offset(void);
extern void enter_prom(struct prom_args *args, unsigned long entry);
extern void copy_and_flush(unsigned long dest, unsigned long src,
			   unsigned long size, unsigned long offset);

extern unsigned long klimit;

//int global_width = 640, global_height = 480, global_depth = 8, global_pitch;
//unsigned global_address;
/* prom structure */
static struct prom_t __initdata prom;

#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;

static int __initdata iommu_force_on;
static int __initdata ppc64_iommu_off;
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

/* TO GO */
#ifdef CONFIG_HMT
struct {
	unsigned int pir;
	unsigned int threadid;
} hmt_thread_data[NR_CPUS];
#endif /* CONFIG_HMT */

/*
 * This are used in calls to call_prom.  The 4th and following
 * arguments to call_prom should be 32-bit values.  64 bit values
 * are truncated to 32 bits (and fortunately don't get interpreted
 * as two arguments).
 */
#define ADDR(x)		(u32) ((unsigned long)(x) - offset)

/* This is the one and *ONLY* place where we actually call open
 * firmware from, since we need to make sure we're running in 32b
 * mode when we do.  We switch back to 64b mode upon return.
 */

#define PROM_ERROR	(-1)

static int __init call_prom(const char *service, int nargs, int nret, ...)
{
	int i;
	unsigned long offset = reloc_offset();
	struct prom_t *_prom = PTRRELOC(&prom);
	va_list list;

	_prom->args.service = ADDR(service);
	_prom->args.nargs = nargs;
	_prom->args.nret = nret;
	_prom->args.rets = (prom_arg_t *)&(_prom->args.args[nargs]);

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

	for (i=0; i < nret ;i++)
		_prom->args.rets[i] = 0;

	enter_prom(&_prom->args, _prom->entry);

	return (nret > 0) ? _prom->args.rets[0] : 0;
}


static unsigned int __init prom_claim(unsigned long virt, unsigned long size,
				unsigned long align)
{
	return (unsigned int)call_prom("claim", 3, 1,
				       (prom_arg_t)virt, (prom_arg_t)size,
				       (prom_arg_t)align);
}

static void __init prom_print(const char *msg)
{
	const char *p, *q;
	unsigned long offset = reloc_offset();
	struct prom_t *_prom = PTRRELOC(&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)
{
	unsigned long offset = reloc_offset();
	int i, nibbles = sizeof(val)*2;
	char buf[sizeof(val)*2+1];
	struct prom_t *_prom = PTRRELOC(&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, ...)
{
	unsigned long offset = reloc_offset();
	const char *p, *q, *s;
	va_list args;
	unsigned long v;
	struct prom_t *_prom = PTRRELOC(&prom);

	va_start(args, format);
	for (p = PTRRELOC(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 void __init __attribute__((noreturn)) prom_panic(const char *reason)
{
	unsigned long offset = reloc_offset();

	prom_print(PTRRELOC(reason));
	/* ToDo: should put up an SRC here */
	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 __init prom_getprop(phandle node, const char *pname,
			       void *value, size_t valuelen)
{
	unsigned long offset = reloc_offset();

	return call_prom("getprop", 4, 1, node, ADDR(pname),
			 (u32)(unsigned long) value, (u32) valuelen);
}

static int __init prom_getproplen(phandle node, const char *pname)
{
	unsigned long offset = reloc_offset();

	return call_prom("getproplen", 2, 1, node, ADDR(pname));
}

static int __init prom_setprop(phandle node, const char *pname,
			       void *value, size_t valuelen)
{
	unsigned long offset = reloc_offset();

	return call_prom("setprop", 4, 1, node, ADDR(pname),
			 (u32)(unsigned long) value, (u32) valuelen);
}


/*
 * Early parsing of the command line passed to the kernel, used for
 * the options that affect the iommu
 */
static void __init early_cmdline_parse(void)
{
	unsigned long offset = reloc_offset();
	struct prom_t *_prom = PTRRELOC(&prom);
	char *opt, *p;
	int l = 0;

	RELOC(prom_cmd_line[0]) = 0;
	p = RELOC(prom_cmd_line);
	if ((long)_prom->chosen > 0)
		l = prom_getprop(_prom->chosen, "bootargs", p, COMMAND_LINE_SIZE-1);
#ifdef CONFIG_CMDLINE
	if (l == 0) /* dbl check */
		strlcpy(RELOC(prom_cmd_line),
			RELOC(CONFIG_CMDLINE), sizeof(prom_cmd_line));
#endif /* CONFIG_CMDLINE */
	prom_printf("command line: %s\n", RELOC(prom_cmd_line));

	opt = strstr(RELOC(prom_cmd_line), RELOC("iommu="));
	if (opt) {
		prom_printf("iommu opt is: %s\n", opt);
		opt += 6;
		while (*opt && *opt == ' ')
			opt++;
		if (!strncmp(opt, RELOC("off"), 3))
			RELOC(ppc64_iommu_off) = 1;
		else if (!strncmp(opt, RELOC("force"), 5))
			RELOC(iommu_force_on) = 1;
	}
}

/*
 * Memory allocation strategy... our layout is normally: