setup.c

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/*
 * 
 * Common boot and setup code.
 *
 * Copyright (C) 2001 PPC64 Team, IBM Corp
 *
 *      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

#include <linux/config.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/reboot.h>
#include <linux/delay.h>
#include <linux/initrd.h>
#include <linux/ide.h>
#include <linux/seq_file.h>
#include <linux/ioport.h>
#include <linux/console.h>
#include <linux/utsname.h>
#include <linux/tty.h>
#include <linux/root_dev.h>
#include <linux/notifier.h>
#include <linux/cpu.h>
#include <linux/unistd.h>
#include <linux/serial.h>
#include <linux/serial_8250.h>
#include <asm/io.h>
#include <asm/prom.h>
#include <asm/processor.h>
#include <asm/pgtable.h>
#include <asm/bootinfo.h>
#include <asm/smp.h>
#include <asm/elf.h>
#include <asm/machdep.h>
#include <asm/paca.h>
#include <asm/ppcdebug.h>
#include <asm/time.h>
#include <asm/cputable.h>
#include <asm/sections.h>
#include <asm/btext.h>
#include <asm/nvram.h>
#include <asm/setup.h>
#include <asm/system.h>
#include <asm/rtas.h>
#include <asm/iommu.h>
#include <asm/serial.h>
#include <asm/cache.h>
#include <asm/page.h>
#include <asm/mmu.h>
#include <asm/lmb.h>
#include <asm/iSeries/ItLpNaca.h>

#ifdef DEBUG
#define DBG(fmt...) udbg_printf(fmt)
#else
#define DBG(fmt...)
#endif

/*
 * Here are some early debugging facilities. You can enable one
 * but your kernel will not boot on anything else if you do so
 */

/* This one is for use on LPAR machines that support an HVC console
 * on vterm 0
 */
extern void udbg_init_debug_lpar(void);
/* This one is for use on Apple G5 machines
 */
extern void udbg_init_pmac_realmode(void);
/* That's RTAS panel debug */
extern void call_rtas_display_status_delay(unsigned char c);
/* Here's maple real mode debug */
extern void udbg_init_maple_realmode(void);

#define EARLY_DEBUG_INIT() do {} while(0)

#if 0
#define EARLY_DEBUG_INIT() udbg_init_debug_lpar()
#define EARLY_DEBUG_INIT() udbg_init_maple_realmode()
#define EARLY_DEBUG_INIT() udbg_init_pmac_realmode()
#define EARLY_DEBUG_INIT()						\
	do { udbg_putc = call_rtas_display_status_delay; } while(0)
#endif

/* extern void *stab; */
extern unsigned long klimit;

extern void mm_init_ppc64(void);
extern void stab_initialize(unsigned long stab);
extern void htab_initialize(void);
extern void early_init_devtree(void *flat_dt);
extern void unflatten_device_tree(void);

extern void smp_release_cpus(void);

int have_of = 1;
int boot_cpuid = 0;
int boot_cpuid_phys = 0;
dev_t boot_dev;
u64 ppc64_pft_size;

struct ppc64_caches ppc64_caches;
EXPORT_SYMBOL_GPL(ppc64_caches);

/*
 * These are used in binfmt_elf.c to put aux entries on the stack
 * for each elf executable being started.
 */
int dcache_bsize;
int icache_bsize;
int ucache_bsize;

/* The main machine-dep calls structure
 */
struct machdep_calls ppc_md;
EXPORT_SYMBOL(ppc_md);

#ifdef CONFIG_MAGIC_SYSRQ
unsigned long SYSRQ_KEY;
#endif /* CONFIG_MAGIC_SYSRQ */


static int ppc64_panic_event(struct notifier_block *, unsigned long, void *);
static struct notifier_block ppc64_panic_block = {
	.notifier_call = ppc64_panic_event,
	.priority = INT_MIN /* may not return; must be done last */
};

/*
 * Perhaps we can put the pmac screen_info[] here
 * on pmac as well so we don't need the ifdef's.
 * Until we get multiple-console support in here
 * that is.  -- Cort
 * Maybe tie it to serial consoles, since this is really what
 * these processors use on existing boards.  -- Dan
 */ 
struct screen_info screen_info = {
	.orig_x = 0,
	.orig_y = 25,
	.orig_video_cols = 80,
	.orig_video_lines = 25,
	.orig_video_isVGA = 1,
	.orig_video_points = 16
};

#if defined(CONFIG_PPC_MULTIPLATFORM) && defined(CONFIG_SMP)

static int smt_enabled_cmdline;

/* Look for ibm,smt-enabled OF option */
static void check_smt_enabled(void)
{
	struct device_node *dn;
	char *smt_option;

	/* Allow the command line to overrule the OF option */
	if (smt_enabled_cmdline)
		return;

	dn = of_find_node_by_path("/options");

	if (dn) {
		smt_option = (char *)get_property(dn, "ibm,smt-enabled", NULL);

                if (smt_option) {
			if (!strcmp(smt_option, "on"))
				smt_enabled_at_boot = 1;
			else if (!strcmp(smt_option, "off"))
				smt_enabled_at_boot = 0;
                }
        }
}

/* Look for smt-enabled= cmdline option */
static int __init early_smt_enabled(char *p)
{
	smt_enabled_cmdline = 1;

	if (!p)
		return 0;

	if (!strcmp(p, "on") || !strcmp(p, "1"))
		smt_enabled_at_boot = 1;
	else if (!strcmp(p, "off") || !strcmp(p, "0"))
		smt_enabled_at_boot = 0;

	return 0;
}
early_param("smt-enabled", early_smt_enabled);

/**
 * setup_cpu_maps - initialize the following cpu maps:
 *                  cpu_possible_map
 *                  cpu_present_map
 *                  cpu_sibling_map
 *
 * Having the possible map set up early allows us to restrict allocations
 * of things like irqstacks to num_possible_cpus() rather than NR_CPUS.
 *
 * We do not initialize the online map here; cpus set their own bits in
 * cpu_online_map as they come up.
 *
 * This function is valid only for Open Firmware systems.  finish_device_tree
 * must be called before using this.
 *
 * While we're here, we may as well set the "physical" cpu ids in the paca.
 */
static void __init setup_cpu_maps(void)
{
	struct device_node *dn = NULL;
	int cpu = 0;
	int swap_cpuid = 0;

	check_smt_enabled();

	while ((dn = of_find_node_by_type(dn, "cpu")) && cpu < NR_CPUS) {
		u32 *intserv;
		int j, len = sizeof(u32), nthreads;

		intserv = (u32 *)get_property(dn, "ibm,ppc-interrupt-server#s",
					      &len);
		if (!intserv)
			intserv = (u32 *)get_property(dn, "reg", NULL);

		nthreads = len / sizeof(u32);

		for (j = 0; j < nthreads && cpu < NR_CPUS; j++) {
			cpu_set(cpu, cpu_present_map);
			set_hard_smp_processor_id(cpu, intserv[j]);

			if (intserv[j] == boot_cpuid_phys)
				swap_cpuid = cpu;
			cpu_set(cpu, cpu_possible_map);
			cpu++;
		}
	}

	/* Swap CPU id 0 with boot_cpuid_phys, so we can always assume that
	 * boot cpu is logical 0.
	 */
	if (boot_cpuid_phys != get_hard_smp_processor_id(0)) {
		u32 tmp;
		tmp = get_hard_smp_processor_id(0);
		set_hard_smp_processor_id(0, boot_cpuid_phys);
		set_hard_smp_processor_id(swap_cpuid, tmp);
	}

	/*
	 * On pSeries LPAR, we need to know how many cpus
	 * could possibly be added to this partition.
	 */
	if (systemcfg->platform == PLATFORM_PSERIES_LPAR &&
				(dn = of_find_node_by_path("/rtas"))) {
		int num_addr_cell, num_size_cell, maxcpus;
		unsigned int *ireg;

		num_addr_cell = prom_n_addr_cells(dn);
		num_size_cell = prom_n_size_cells(dn);

		ireg = (unsigned int *)
			get_property(dn, "ibm,lrdr-capacity", NULL);

		if (!ireg)
			goto out;

		maxcpus = ireg[num_addr_cell + num_size_cell];

		/* Double maxcpus for processors which have SMT capability */
		if (cpu_has_feature(CPU_FTR_SMT))
			maxcpus *= 2;

		if (maxcpus > NR_CPUS) {
			printk(KERN_WARNING
			       "Partition configured for %d cpus, "
			       "operating system maximum is %d.\n",
			       maxcpus, NR_CPUS);
			maxcpus = NR_CPUS;
		} else
			printk(KERN_INFO "Partition configured for %d cpus.\n",
			       maxcpus);

		for (cpu = 0; cpu < maxcpus; cpu++)
			cpu_set(cpu, cpu_possible_map);
	out:
		of_node_put(dn);
	}

	/*
	 * Do the sibling map; assume only two threads per processor.
	 */
	for_each_cpu(cpu) {
		cpu_set(cpu, cpu_sibling_map[cpu]);
		if (cpu_has_feature(CPU_FTR_SMT))
			cpu_set(cpu ^ 0x1, cpu_sibling_map[cpu]);
	}

	systemcfg->processorCount = num_present_cpus();
}
#endif /* defined(CONFIG_PPC_MULTIPLATFORM) && defined(CONFIG_SMP) */


#ifdef CONFIG_PPC_MULTIPLATFORM

extern struct machdep_calls pSeries_md;
extern struct machdep_calls pmac_md;
extern struct machdep_calls maple_md;
extern struct machdep_calls bpa_md;

/* Ultimately, stuff them in an elf section like initcalls... */
static struct machdep_calls __initdata *machines[] = {
#ifdef CONFIG_PPC_PSERIES
	&pSeries_md,
#endif /* CONFIG_PPC_PSERIES */
#ifdef CONFIG_PPC_PMAC
	&pmac_md,
#endif /* CONFIG_PPC_PMAC */
#ifdef CONFIG_PPC_MAPLE
	&maple_md,
#endif /* CONFIG_PPC_MAPLE */
#ifdef CONFIG_PPC_BPA
	&bpa_md,
#endif
	NULL
};

/*
 * Early initialization entry point. This is called by head.S
 * with MMU translation disabled. We rely on the "feature" of
 * the CPU that ignores the top 2 bits of the address in real
 * mode so we can access kernel globals normally provided we
 * only toy with things in the RMO region. From here, we do
 * some early parsing of the device-tree to setup out LMB
 * data structures, and allocate & initialize the hash table
 * and segment tables so we can start running with translation
 * enabled.
 *
 * It is this function which will call the probe() callback of
 * the various platform types and copy the matching one to the
 * global ppc_md structure. Your platform can eventually do
 * some very early initializations from the probe() routine, but
 * this is not recommended, be very careful as, for example, the
 * device-tree is not accessible via normal means at this point.
 */

void __init early_setup(unsigned long dt_ptr)
{
	struct paca_struct *lpaca = get_paca();
	static struct machdep_calls **mach;

	/*
	 * Enable early debugging if any specified (see top of
	 * this file)
	 */
	EARLY_DEBUG_INIT();

	DBG(" -> early_setup()\n");

	/*
	 * Fill the default DBG level (do we want to keep
	 * that old mecanism around forever ?)
	 */
	ppcdbg_initialize();

	/*
	 * Do early initializations using the flattened device
	 * tree, like retreiving the physical memory map or
	 * calculating/retreiving the hash table size
	 */
	early_init_devtree(__va(dt_ptr));

	/*
	 * Iterate all ppc_md structures until we find the proper
	 * one for the current machine type
	 */
	DBG("Probing machine type for platform %x...\n",
	    systemcfg->platform);

	for (mach = machines; *mach; mach++) {
		if ((*mach)->probe(systemcfg->platform))
			break;
	}
	/* What can we do if we didn't find ? */
	if (*mach == NULL) {
		DBG("No suitable machine found !\n");
		for (;;);
	}
	ppc_md = **mach;

	DBG("Found, Initializing memory management...\n");

	/*
	 * Initialize stab / SLB management
	 */
	stab_initialize(lpaca->stab_real);

	/*
	 * Initialize the MMU Hash table and create the linear mapping
	 * of memory
	 */
	htab_initialize();

	DBG(" <- early_setup()\n");
}


/*
 * Initialize some remaining members of the ppc64_caches and systemcfg structures
 * (at least until we get rid of them completely). This is mostly some
 * cache informations about the CPU that will be used by cache flush
 * routines and/or provided to userland
 */
static void __init initialize_cache_info(void)
{
	struct device_node *np;
	unsigned long num_cpus = 0;

	DBG(" -> initialize_cache_info()\n");

	for (np = NULL; (np = of_find_node_by_type(np, "cpu"));) {
		num_cpus += 1;

		/* We're assuming *all* of the CPUs have the same
		 * d-cache and i-cache sizes... -Peter
		 */

		if ( num_cpus == 1 ) {
			u32 *sizep, *lsizep;
			u32 size, lsize;
			const char *dc, *ic;