arch/ppc64/kernel/pSeries_setup.c - kernel/msm-5.4 - Gitiles

 /*
  *  linux/arch/ppc/kernel/setup.c
  *
  *  Copyright (C) 1995  Linus Torvalds
  *  Adapted from 'alpha' version by Gary Thomas
  *  Modified by Cort Dougan (cort@cs.nmt.edu)
  *  Modified by 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.
  */

 /*
  * bootup setup stuff..
  */

 #undef DEBUG

 #include <linux/config.h>
 #include <linux/cpu.h>
 #include <linux/errno.h>
 #include <linux/sched.h>
 #include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/stddef.h>
 #include <linux/unistd.h>
 #include <linux/slab.h>
 #include <linux/user.h>
 #include <linux/a.out.h>
 #include <linux/tty.h>
 #include <linux/major.h>
 #include <linux/interrupt.h>
 #include <linux/reboot.h>
 #include <linux/init.h>
 #include <linux/ioport.h>
 #include <linux/console.h>
 #include <linux/pci.h>
 #include <linux/version.h>
 #include <linux/adb.h>
 #include <linux/module.h>
 #include <linux/delay.h>
 #include <linux/irq.h>
 #include <linux/seq_file.h>
 #include <linux/root_dev.h>

 #include <asm/mmu.h>
 #include <asm/processor.h>
 #include <asm/io.h>
 #include <asm/pgtable.h>
 #include <asm/prom.h>
 #include <asm/rtas.h>
 #include <asm/pci-bridge.h>
 #include <asm/iommu.h>
 #include <asm/dma.h>
 #include <asm/machdep.h>
 #include <asm/irq.h>
 #include <asm/time.h>
 #include <asm/nvram.h>
 #include <asm/plpar_wrappers.h>
 #include <asm/xics.h>
 #include <asm/firmware.h>
 #include <asm/pmc.h>

 #include "i8259.h"
 #include "mpic.h"
 #include "pci.h"

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

 extern void find_udbg_vterm(void);
 extern void system_reset_fwnmi(void);	/* from head.S */
 extern void machine_check_fwnmi(void);	/* from head.S */
 extern void generic_find_legacy_serial_ports(u64 *physport,
 		unsigned int *default_speed);

 int fwnmi_active;  /* TRUE if an FWNMI handler is present */

 extern void pSeries_system_reset_exception(struct pt_regs *regs);
 extern int pSeries_machine_check_exception(struct pt_regs *regs);

 static int pseries_shared_idle(void);
 static int pseries_dedicated_idle(void);

 static volatile void __iomem * chrp_int_ack_special;
 struct mpic *pSeries_mpic;

 void pSeries_get_cpuinfo(struct seq_file *m)
 {
 	struct device_node *root;
 	const char *model = "";

 	root = of_find_node_by_path("/");
 	if (root)
 		model = get_property(root, "model", NULL);
 	seq_printf(m, "machine\t\t: CHRP %s\n", model);
 	of_node_put(root);
 }

 /* Initialize firmware assisted non-maskable interrupts if
  * the firmware supports this feature.
  *
  */
 static void __init fwnmi_init(void)
 {
 	int ret;
 	int ibm_nmi_register = rtas_token("ibm,nmi-register");
 	if (ibm_nmi_register == RTAS_UNKNOWN_SERVICE)
 		return;
 	ret = rtas_call(ibm_nmi_register, 2, 1, NULL,
 			__pa((unsigned long)system_reset_fwnmi),
 			__pa((unsigned long)machine_check_fwnmi));
 	if (ret == 0)
 		fwnmi_active = 1;
 }

 static int pSeries_irq_cascade(struct pt_regs *regs, void *data)
 {
 	if (chrp_int_ack_special)
 		return readb(chrp_int_ack_special);
 	else
 		return i8259_irq(smp_processor_id());
 }

 static void __init pSeries_init_mpic(void)
 {
         unsigned int *addrp;
 	struct device_node *np;
         int i;

 	/* All ISUs are setup, complete initialization */
 	mpic_init(pSeries_mpic);

 	/* Check what kind of cascade ACK we have */
         if (!(np = of_find_node_by_name(NULL, "pci"))
             || !(addrp = (unsigned int *)
                  get_property(np, "8259-interrupt-acknowledge", NULL)))
                 printk(KERN_ERR "Cannot find pci to get ack address\n");
         else
 		chrp_int_ack_special = ioremap(addrp[prom_n_addr_cells(np)-1], 1);
 	of_node_put(np);

 	/* Setup the legacy interrupts & controller */
         for (i = 0; i < NUM_ISA_INTERRUPTS; i++)
                 irq_desc[i].handler = &i8259_pic;
 	i8259_init(0);

 	/* Hook cascade to mpic */
 	mpic_setup_cascade(NUM_ISA_INTERRUPTS, pSeries_irq_cascade, NULL);
 }

 static void __init pSeries_setup_mpic(void)
 {
 	unsigned int *opprop;
 	unsigned long openpic_addr = 0;
         unsigned char senses[NR_IRQS - NUM_ISA_INTERRUPTS];
         struct device_node *root;
 	int irq_count;

 	/* Find the Open PIC if present */
 	root = of_find_node_by_path("/");
 	opprop = (unsigned int *) get_property(root, "platform-open-pic", NULL);
 	if (opprop != 0) {
 		int n = prom_n_addr_cells(root);

 		for (openpic_addr = 0; n > 0; --n)
 			openpic_addr = (openpic_addr << 32) + *opprop++;
 		printk(KERN_DEBUG "OpenPIC addr: %lx\n", openpic_addr);
 	}
 	of_node_put(root);

 	BUG_ON(openpic_addr == 0);

 	/* Get the sense values from OF */
 	prom_get_irq_senses(senses, NUM_ISA_INTERRUPTS, NR_IRQS);

 	/* Setup the openpic driver */
 	irq_count = NR_IRQS - NUM_ISA_INTERRUPTS - 4; /* leave room for IPIs */
 	pSeries_mpic = mpic_alloc(openpic_addr, MPIC_PRIMARY,
 				  16, 16, irq_count, /* isu size, irq offset, irq count */
 				  NR_IRQS - 4, /* ipi offset */
 				  senses, irq_count, /* sense & sense size */
 				  " MPIC     ");
 }

 static void pseries_lpar_enable_pmcs(void)
 {
 	unsigned long set, reset;

 	power4_enable_pmcs();

 	set = 1UL << 63;
 	reset = 0;
 	plpar_hcall_norets(H_PERFMON, set, reset);

 	/* instruct hypervisor to maintain PMCs */
 	if (firmware_has_feature(FW_FEATURE_SPLPAR))
 		get_paca()->lppaca.pmcregs_in_use = 1;
 }

 static void __init pSeries_setup_arch(void)
 {
 	/* Fixup ppc_md depending on the type of interrupt controller */
 	if (ppc64_interrupt_controller == IC_OPEN_PIC) {
 		ppc_md.init_IRQ       = pSeries_init_mpic;
 		ppc_md.get_irq        = mpic_get_irq;
 	 	ppc_md.cpu_irq_down   = mpic_teardown_this_cpu;
 		/* Allocate the mpic now, so that find_and_init_phbs() can
 		 * fill the ISUs */
 		pSeries_setup_mpic();
 	} else {
 		ppc_md.init_IRQ       = xics_init_IRQ;
 		ppc_md.get_irq        = xics_get_irq;
 		ppc_md.cpu_irq_down   = xics_teardown_cpu;
 	}

 #ifdef CONFIG_SMP
 	smp_init_pSeries();
 #endif
 	/* openpic global configuration register (64-bit format). */
 	/* openpic Interrupt Source Unit pointer (64-bit format). */
 	/* python0 facility area (mmio) (64-bit format) REAL address. */

 	/* init to some ~sane value until calibrate_delay() runs */
 	loops_per_jiffy = 50000000;

 	if (ROOT_DEV == 0) {
 		printk("No ramdisk, default root is /dev/sda2\n");
 		ROOT_DEV = Root_SDA2;
 	}

 	fwnmi_init();

 	/* Find and initialize PCI host bridges */
 	init_pci_config_tokens();
 	eeh_init();
 	find_and_init_phbs();

 #ifdef CONFIG_DUMMY_CONSOLE
 	conswitchp = &dummy_con;
 #endif

 	pSeries_nvram_init();

 	/* Choose an idle loop */
 	if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
 		vpa_init(boot_cpuid);
 		if (get_paca()->lppaca.shared_proc) {
 			printk(KERN_INFO "Using shared processor idle loop\n");
 			ppc_md.idle_loop = pseries_shared_idle;
 		} else {
 			printk(KERN_INFO "Using dedicated idle loop\n");
 			ppc_md.idle_loop = pseries_dedicated_idle;
 		}
 	} else {
 		printk(KERN_INFO "Using default idle loop\n");
 		ppc_md.idle_loop = default_idle;
 	}

 	if (systemcfg->platform & PLATFORM_LPAR)
 		ppc_md.enable_pmcs = pseries_lpar_enable_pmcs;
 	else
 		ppc_md.enable_pmcs = power4_enable_pmcs;
 }

 static int __init pSeries_init_panel(void)
 {
 	/* Manually leave the kernel version on the panel. */
 	ppc_md.progress("Linux ppc64\n", 0);
 	ppc_md.progress(UTS_RELEASE, 0);

 	return 0;
 }
 arch_initcall(pSeries_init_panel);


 /* Build up the ppc64_firmware_features bitmask field
  * using contents of device-tree/ibm,hypertas-functions.
  * Ultimately this functionality may be moved into prom.c prom_init().
  */
 static void __init fw_feature_init(void)
 {
 	struct device_node * dn;
 	char * hypertas;
 	unsigned int len;

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

 	ppc64_firmware_features = 0;
 	dn = of_find_node_by_path("/rtas");
 	if (dn == NULL) {
 		printk(KERN_ERR "WARNING ! Cannot find RTAS in device-tree !\n");
 		goto no_rtas;
 	}

 	hypertas = get_property(dn, "ibm,hypertas-functions", &len);
 	if (hypertas) {
 		while (len > 0){
 			int i, hypertas_len;
 			/* check value against table of strings */
 			for(i=0; i < FIRMWARE_MAX_FEATURES ;i++) {
 				if ((firmware_features_table[i].name) &&
 				    (strcmp(firmware_features_table[i].name,hypertas))==0) {
 					/* we have a match */
 					ppc64_firmware_features |=
 						(firmware_features_table[i].val);
 					break;
 				}
 			}
 			hypertas_len = strlen(hypertas);
 			len -= hypertas_len +1;
 			hypertas+= hypertas_len +1;
 		}
 	}

 	of_node_put(dn);
  no_rtas:
 	printk(KERN_INFO "firmware_features = 0x%lx\n",
 	       ppc64_firmware_features);

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


 static  void __init pSeries_discover_pic(void)
 {
 	struct device_node *np;
 	char *typep;

 	/*
 	 * Setup interrupt mapping options that are needed for finish_device_tree
 	 * to properly parse the OF interrupt tree & do the virtual irq mapping
 	 */
 	__irq_offset_value = NUM_ISA_INTERRUPTS;
 	ppc64_interrupt_controller = IC_INVALID;
 	for (np = NULL; (np = of_find_node_by_name(np, "interrupt-controller"));) {
 		typep = (char *)get_property(np, "compatible", NULL);
 		if (strstr(typep, "open-pic"))
 			ppc64_interrupt_controller = IC_OPEN_PIC;
 		else if (strstr(typep, "ppc-xicp"))
 			ppc64_interrupt_controller = IC_PPC_XIC;
 		else
 			printk("pSeries_discover_pic: failed to recognize"
 			       " interrupt-controller\n");
 		break;
 	}
 }

 static void pSeries_mach_cpu_die(void)
 {
 	local_irq_disable();
 	idle_task_exit();
 	/* Some hardware requires clearing the CPPR, while other hardware does not
 	 * it is safe either way
 	 */
 	pSeriesLP_cppr_info(0, 0);
 	rtas_stop_self();
 	/* Should never get here... */
 	BUG();
 	for(;;);
 }


 /*
  * Early initialization.  Relocation is on but do not reference unbolted pages
  */
 static void __init pSeries_init_early(void)
 {
 	void *comport;
 	int iommu_off = 0;
 	unsigned int default_speed;
 	u64 physport;

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

 	fw_feature_init();

 	if (systemcfg->platform & PLATFORM_LPAR)
 		hpte_init_lpar();
 	else {
 		hpte_init_native();
 		iommu_off = (of_chosen &&
 			     get_property(of_chosen, "linux,iommu-off", NULL));
 	}

 	generic_find_legacy_serial_ports(&physport, &default_speed);

 	if (systemcfg->platform & PLATFORM_LPAR)
 		find_udbg_vterm();
 	else if (physport) {
 		/* Map the uart for udbg. */
 		comport = (void *)ioremap(physport, 16);
 		udbg_init_uart(comport, default_speed);

 		ppc_md.udbg_putc = udbg_putc;
 		ppc_md.udbg_getc = udbg_getc;
 		ppc_md.udbg_getc_poll = udbg_getc_poll;
 		DBG("Hello World !\n");
 	}


 	iommu_init_early_pSeries();

 	pSeries_discover_pic();

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


 static int pSeries_check_legacy_ioport(unsigned int baseport)
 {
 	struct device_node *np;

 #define I8042_DATA_REG	0x60
 #define FDC_BASE	0x3f0


 	switch(baseport) {
 	case I8042_DATA_REG:
 		np = of_find_node_by_type(NULL, "8042");
 		if (np == NULL)
 			return -ENODEV;
 		of_node_put(np);
 		break;
 	case FDC_BASE:
 		np = of_find_node_by_type(NULL, "fdc");
 		if (np == NULL)
 			return -ENODEV;
 		of_node_put(np);
 		break;
 	}
 	return 0;
 }

 /*
  * Called very early, MMU is off, device-tree isn't unflattened
  */
 extern struct machdep_calls pSeries_md;

 static int __init pSeries_probe(int platform)
 {
 	if (platform != PLATFORM_PSERIES &&
 	    platform != PLATFORM_PSERIES_LPAR)
 		return 0;

 	/* if we have some ppc_md fixups for LPAR to do, do
 	 * it here ...
 	 */

 	return 1;
 }

 DECLARE_PER_CPU(unsigned long, smt_snooze_delay);

 static inline void dedicated_idle_sleep(unsigned int cpu)
 {
 	struct paca_struct *ppaca = &paca[cpu ^ 1];

 	/* Only sleep if the other thread is not idle */
 	if (!(ppaca->lppaca.idle)) {
 		local_irq_disable();

 		/*
 		 * We are about to sleep the thread and so wont be polling any
 		 * more.
 		 */
 		clear_thread_flag(TIF_POLLING_NRFLAG);

 		/*
 		 * SMT dynamic mode. Cede will result in this thread going
 		 * dormant, if the partner thread is still doing work.  Thread
 		 * wakes up if partner goes idle, an interrupt is presented, or
 		 * a prod occurs.  Returning from the cede enables external
 		 * interrupts.
 		 */
 		if (!need_resched())
 			cede_processor();
 		else
 			local_irq_enable();
 	} else {
 		/*
 		 * Give the HV an opportunity at the processor, since we are
 		 * not doing any work.
 		 */
 		poll_pending();
 	}
 }

 static int pseries_dedicated_idle(void)
 {
 	long oldval;
 	struct paca_struct *lpaca = get_paca();
 	unsigned int cpu = smp_processor_id();
 	unsigned long start_snooze;
 	unsigned long *smt_snooze_delay = &__get_cpu_var(smt_snooze_delay);

 	while (1) {
 		/*
 		 * Indicate to the HV that we are idle. Now would be
 		 * a good time to find other work to dispatch.
 		 */
 		lpaca->lppaca.idle = 1;

 		oldval = test_and_clear_thread_flag(TIF_NEED_RESCHED);
 		if (!oldval) {
 			set_thread_flag(TIF_POLLING_NRFLAG);

 			start_snooze = __get_tb() +
 				*smt_snooze_delay * tb_ticks_per_usec;

 			while (!need_resched() && !cpu_is_offline(cpu)) {
 				ppc64_runlatch_off();

 				/*
 				 * Go into low thread priority and possibly
 				 * low power mode.
 				 */
 				HMT_low();
 				HMT_very_low();

 				if (*smt_snooze_delay != 0 &&
 				    __get_tb() > start_snooze) {
 					HMT_medium();
 					dedicated_idle_sleep(cpu);
 				}

 			}

 			HMT_medium();
 			clear_thread_flag(TIF_POLLING_NRFLAG);
 		} else {
 			set_need_resched();
 		}

 		lpaca->lppaca.idle = 0;
 		ppc64_runlatch_on();

 		schedule();

 		if (cpu_is_offline(cpu) && system_state == SYSTEM_RUNNING)
 			cpu_die();
 	}
 }

 static int pseries_shared_idle(void)
 {
 	struct paca_struct *lpaca = get_paca();
 	unsigned int cpu = smp_processor_id();

 	while (1) {
 		/*
 		 * Indicate to the HV that we are idle. Now would be
 		 * a good time to find other work to dispatch.
 		 */
 		lpaca->lppaca.idle = 1;

 		while (!need_resched() && !cpu_is_offline(cpu)) {
 			local_irq_disable();
 			ppc64_runlatch_off();

 			/*
 			 * Yield the processor to the hypervisor.  We return if
 			 * an external interrupt occurs (which are driven prior
 			 * to returning here) or if a prod occurs from another
 			 * processor. When returning here, external interrupts
 			 * are enabled.
 			 *
 			 * Check need_resched() again with interrupts disabled
 			 * to avoid a race.
 			 */
 			if (!need_resched())
 				cede_processor();
 			else
 				local_irq_enable();

 			HMT_medium();
 		}

 		lpaca->lppaca.idle = 0;
 		ppc64_runlatch_on();

 		schedule();

 		if (cpu_is_offline(cpu) && system_state == SYSTEM_RUNNING)
 			cpu_die();
 	}

 	return 0;
 }

 struct machdep_calls __initdata pSeries_md = {
 	.probe			= pSeries_probe,
 	.setup_arch		= pSeries_setup_arch,
 	.init_early		= pSeries_init_early,
 	.get_cpuinfo		= pSeries_get_cpuinfo,
 	.log_error		= pSeries_log_error,
 	.pcibios_fixup		= pSeries_final_fixup,
 	.irq_bus_setup		= pSeries_irq_bus_setup,
 	.restart		= rtas_restart,
 	.power_off		= rtas_power_off,
 	.halt			= rtas_halt,
 	.panic			= rtas_os_term,
 	.cpu_die		= pSeries_mach_cpu_die,
 	.get_boot_time		= rtas_get_boot_time,
 	.get_rtc_time		= rtas_get_rtc_time,
 	.set_rtc_time		= rtas_set_rtc_time,
 	.calibrate_decr		= generic_calibrate_decr,
 	.progress		= rtas_progress,
 	.check_legacy_ioport	= pSeries_check_legacy_ioport,
 	.system_reset_exception = pSeries_system_reset_exception,
 	.machine_check_exception = pSeries_machine_check_exception,
 };
	/*
	* linux/arch/ppc/kernel/setup.c
	*
	* Copyright (C) 1995 Linus Torvalds
	* Adapted from 'alpha' version by Gary Thomas
	* Modified by Cort Dougan (cort@cs.nmt.edu)
	* Modified by 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.
	*/

	/*
	* bootup setup stuff..
	*/

	#undef DEBUG

	#include <linux/config.h>
	#include <linux/cpu.h>
	#include <linux/errno.h>
	#include <linux/sched.h>
	#include <linux/kernel.h>
	#include <linux/mm.h>
	#include <linux/stddef.h>
	#include <linux/unistd.h>
	#include <linux/slab.h>
	#include <linux/user.h>
	#include <linux/a.out.h>
	#include <linux/tty.h>
	#include <linux/major.h>
	#include <linux/interrupt.h>
	#include <linux/reboot.h>
	#include <linux/init.h>
	#include <linux/ioport.h>
	#include <linux/console.h>
	#include <linux/pci.h>
	#include <linux/version.h>
	#include <linux/adb.h>
	#include <linux/module.h>
	#include <linux/delay.h>
	#include <linux/irq.h>
	#include <linux/seq_file.h>
	#include <linux/root_dev.h>

	#include <asm/mmu.h>
	#include <asm/processor.h>
	#include <asm/io.h>
	#include <asm/pgtable.h>
	#include <asm/prom.h>
	#include <asm/rtas.h>
	#include <asm/pci-bridge.h>
	#include <asm/iommu.h>
	#include <asm/dma.h>
	#include <asm/machdep.h>
	#include <asm/irq.h>
	#include <asm/time.h>
	#include <asm/nvram.h>
	#include <asm/plpar_wrappers.h>
	#include <asm/xics.h>
	#include <asm/firmware.h>
	#include <asm/pmc.h>

	#include "i8259.h"
	#include "mpic.h"
	#include "pci.h"

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

	extern void find_udbg_vterm(void);
	extern void system_reset_fwnmi(void); /* from head.S */
	extern void machine_check_fwnmi(void); /* from head.S */
	extern void generic_find_legacy_serial_ports(u64 *physport,
	unsigned int *default_speed);

	int fwnmi_active; /* TRUE if an FWNMI handler is present */

	extern void pSeries_system_reset_exception(struct pt_regs *regs);
	extern int pSeries_machine_check_exception(struct pt_regs *regs);

	static int pseries_shared_idle(void);
	static int pseries_dedicated_idle(void);

	static volatile void __iomem * chrp_int_ack_special;
	struct mpic *pSeries_mpic;

	void pSeries_get_cpuinfo(struct seq_file *m)
	{
	struct device_node *root;
	const char *model = "";

	root = of_find_node_by_path("/");
	if (root)
	model = get_property(root, "model", NULL);
	seq_printf(m, "machine\t\t: CHRP %s\n", model);
	of_node_put(root);
	}

	/* Initialize firmware assisted non-maskable interrupts if
	* the firmware supports this feature.
	*
	*/
	static void __init fwnmi_init(void)
	{
	int ret;
	int ibm_nmi_register = rtas_token("ibm,nmi-register");
	if (ibm_nmi_register == RTAS_UNKNOWN_SERVICE)
	return;
	ret = rtas_call(ibm_nmi_register, 2, 1, NULL,
	__pa((unsigned long)system_reset_fwnmi),
	__pa((unsigned long)machine_check_fwnmi));
	if (ret == 0)
	fwnmi_active = 1;
	}

	static int pSeries_irq_cascade(struct pt_regs regs, void data)
	{
	if (chrp_int_ack_special)
	return readb(chrp_int_ack_special);
	else
	return i8259_irq(smp_processor_id());
	}

	static void __init pSeries_init_mpic(void)
	{
	unsigned int *addrp;
	struct device_node *np;
	int i;

	/* All ISUs are setup, complete initialization */
	mpic_init(pSeries_mpic);

	/* Check what kind of cascade ACK we have */
	if (!(np = of_find_node_by_name(NULL, "pci"))
	\|\| !(addrp = (unsigned int *)
	get_property(np, "8259-interrupt-acknowledge", NULL)))
	printk(KERN_ERR "Cannot find pci to get ack address\n");
	else
	chrp_int_ack_special = ioremap(addrp[prom_n_addr_cells(np)-1], 1);
	of_node_put(np);

	/* Setup the legacy interrupts & controller */
	for (i = 0; i < NUM_ISA_INTERRUPTS; i++)
	irq_desc[i].handler = &i8259_pic;
	i8259_init(0);

	/* Hook cascade to mpic */
	mpic_setup_cascade(NUM_ISA_INTERRUPTS, pSeries_irq_cascade, NULL);
	}

	static void __init pSeries_setup_mpic(void)
	{
	unsigned int *opprop;
	unsigned long openpic_addr = 0;
	unsigned char senses[NR_IRQS - NUM_ISA_INTERRUPTS];
	struct device_node *root;
	int irq_count;

	/* Find the Open PIC if present */
	root = of_find_node_by_path("/");
	opprop = (unsigned int *) get_property(root, "platform-open-pic", NULL);
	if (opprop != 0) {
	int n = prom_n_addr_cells(root);

	for (openpic_addr = 0; n > 0; --n)
	openpic_addr = (openpic_addr << 32) + *opprop++;
	printk(KERN_DEBUG "OpenPIC addr: %lx\n", openpic_addr);
	}
	of_node_put(root);

	BUG_ON(openpic_addr == 0);

	/* Get the sense values from OF */
	prom_get_irq_senses(senses, NUM_ISA_INTERRUPTS, NR_IRQS);

	/* Setup the openpic driver */
	irq_count = NR_IRQS - NUM_ISA_INTERRUPTS - 4; /* leave room for IPIs */
	pSeries_mpic = mpic_alloc(openpic_addr, MPIC_PRIMARY,
	16, 16, irq_count, /* isu size, irq offset, irq count */
	NR_IRQS - 4, /* ipi offset */
	senses, irq_count, /* sense & sense size */
	" MPIC ");
	}

	static void pseries_lpar_enable_pmcs(void)
	{
	unsigned long set, reset;

	power4_enable_pmcs();

	set = 1UL << 63;
	reset = 0;
	plpar_hcall_norets(H_PERFMON, set, reset);

	/* instruct hypervisor to maintain PMCs */
	if (firmware_has_feature(FW_FEATURE_SPLPAR))
	get_paca()->lppaca.pmcregs_in_use = 1;
	}

	static void __init pSeries_setup_arch(void)
	{
	/* Fixup ppc_md depending on the type of interrupt controller */
	if (ppc64_interrupt_controller == IC_OPEN_PIC) {
	ppc_md.init_IRQ = pSeries_init_mpic;
	ppc_md.get_irq = mpic_get_irq;
	ppc_md.cpu_irq_down = mpic_teardown_this_cpu;
	/* Allocate the mpic now, so that find_and_init_phbs() can
	* fill the ISUs */
	pSeries_setup_mpic();
	} else {
	ppc_md.init_IRQ = xics_init_IRQ;
	ppc_md.get_irq = xics_get_irq;
	ppc_md.cpu_irq_down = xics_teardown_cpu;
	}

	#ifdef CONFIG_SMP
	smp_init_pSeries();
	#endif
	/* openpic global configuration register (64-bit format). */
	/* openpic Interrupt Source Unit pointer (64-bit format). */
	/* python0 facility area (mmio) (64-bit format) REAL address. */

	/* init to some ~sane value until calibrate_delay() runs */
	loops_per_jiffy = 50000000;

	if (ROOT_DEV == 0) {
	printk("No ramdisk, default root is /dev/sda2\n");
	ROOT_DEV = Root_SDA2;
	}

	fwnmi_init();

	/* Find and initialize PCI host bridges */
	init_pci_config_tokens();
	eeh_init();
	find_and_init_phbs();

	#ifdef CONFIG_DUMMY_CONSOLE
	conswitchp = &dummy_con;
	#endif

	pSeries_nvram_init();

	/* Choose an idle loop */
	if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
	vpa_init(boot_cpuid);
	if (get_paca()->lppaca.shared_proc) {
	printk(KERN_INFO "Using shared processor idle loop\n");
	ppc_md.idle_loop = pseries_shared_idle;
	} else {
	printk(KERN_INFO "Using dedicated idle loop\n");
	ppc_md.idle_loop = pseries_dedicated_idle;
	}
	} else {
	printk(KERN_INFO "Using default idle loop\n");
	ppc_md.idle_loop = default_idle;
	}

	if (systemcfg->platform & PLATFORM_LPAR)
	ppc_md.enable_pmcs = pseries_lpar_enable_pmcs;
	else
	ppc_md.enable_pmcs = power4_enable_pmcs;
	}

	static int __init pSeries_init_panel(void)
	{
	/* Manually leave the kernel version on the panel. */
	ppc_md.progress("Linux ppc64\n", 0);
	ppc_md.progress(UTS_RELEASE, 0);

	return 0;
	}
	arch_initcall(pSeries_init_panel);


	/* Build up the ppc64_firmware_features bitmask field
	* using contents of device-tree/ibm,hypertas-functions.
	* Ultimately this functionality may be moved into prom.c prom_init().
	*/
	static void __init fw_feature_init(void)
	{
	struct device_node * dn;
	char * hypertas;
	unsigned int len;

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

	ppc64_firmware_features = 0;
	dn = of_find_node_by_path("/rtas");
	if (dn == NULL) {
	printk(KERN_ERR "WARNING ! Cannot find RTAS in device-tree !\n");
	goto no_rtas;
	}

	hypertas = get_property(dn, "ibm,hypertas-functions", &len);
	if (hypertas) {
	while (len > 0){
	int i, hypertas_len;
	/* check value against table of strings */
	for(i=0; i < FIRMWARE_MAX_FEATURES ;i++) {
	if ((firmware_features_table[i].name) &&
	(strcmp(firmware_features_table[i].name,hypertas))==0) {
	/* we have a match */
	ppc64_firmware_features \|=
	(firmware_features_table[i].val);
	break;
	}
	}
	hypertas_len = strlen(hypertas);
	len -= hypertas_len +1;
	hypertas+= hypertas_len +1;
	}
	}

	of_node_put(dn);
	no_rtas:
	printk(KERN_INFO "firmware_features = 0x%lx\n",
	ppc64_firmware_features);

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


	static void __init pSeries_discover_pic(void)
	{
	struct device_node *np;
	char *typep;

	/*
	* Setup interrupt mapping options that are needed for finish_device_tree
	* to properly parse the OF interrupt tree & do the virtual irq mapping
	*/
	__irq_offset_value = NUM_ISA_INTERRUPTS;
	ppc64_interrupt_controller = IC_INVALID;
	for (np = NULL; (np = of_find_node_by_name(np, "interrupt-controller"));) {
	typep = (char *)get_property(np, "compatible", NULL);
	if (strstr(typep, "open-pic"))
	ppc64_interrupt_controller = IC_OPEN_PIC;
	else if (strstr(typep, "ppc-xicp"))
	ppc64_interrupt_controller = IC_PPC_XIC;
	else
	printk("pSeries_discover_pic: failed to recognize"
	" interrupt-controller\n");
	break;
	}
	}

	static void pSeries_mach_cpu_die(void)
	{
	local_irq_disable();
	idle_task_exit();
	/* Some hardware requires clearing the CPPR, while other hardware does not
	* it is safe either way
	*/
	pSeriesLP_cppr_info(0, 0);
	rtas_stop_self();
	/* Should never get here... */
	BUG();
	for(;;);
	}


	/*
	* Early initialization. Relocation is on but do not reference unbolted pages
	*/
	static void __init pSeries_init_early(void)
	{
	void *comport;
	int iommu_off = 0;
	unsigned int default_speed;
	u64 physport;

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

	fw_feature_init();

	if (systemcfg->platform & PLATFORM_LPAR)
	hpte_init_lpar();
	else {
	hpte_init_native();
	iommu_off = (of_chosen &&
	get_property(of_chosen, "linux,iommu-off", NULL));
	}

	generic_find_legacy_serial_ports(&physport, &default_speed);

	if (systemcfg->platform & PLATFORM_LPAR)
	find_udbg_vterm();
	else if (physport) {
	/* Map the uart for udbg. */
	comport = (void *)ioremap(physport, 16);
	udbg_init_uart(comport, default_speed);

	ppc_md.udbg_putc = udbg_putc;
	ppc_md.udbg_getc = udbg_getc;
	ppc_md.udbg_getc_poll = udbg_getc_poll;
	DBG("Hello World !\n");
	}


	iommu_init_early_pSeries();

	pSeries_discover_pic();

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


	static int pSeries_check_legacy_ioport(unsigned int baseport)
	{
	struct device_node *np;

	#define I8042_DATA_REG 0x60
	#define FDC_BASE 0x3f0


	switch(baseport) {
	case I8042_DATA_REG:
	np = of_find_node_by_type(NULL, "8042");
	if (np == NULL)
	return -ENODEV;
	of_node_put(np);
	break;
	case FDC_BASE:
	np = of_find_node_by_type(NULL, "fdc");
	if (np == NULL)
	return -ENODEV;
	of_node_put(np);
	break;
	}
	return 0;
	}

	/*
	* Called very early, MMU is off, device-tree isn't unflattened
	*/
	extern struct machdep_calls pSeries_md;

	static int __init pSeries_probe(int platform)
	{
	if (platform != PLATFORM_PSERIES &&
	platform != PLATFORM_PSERIES_LPAR)
	return 0;

	/* if we have some ppc_md fixups for LPAR to do, do
	* it here ...
	*/

	return 1;
	}

	DECLARE_PER_CPU(unsigned long, smt_snooze_delay);

	static inline void dedicated_idle_sleep(unsigned int cpu)
	{
	struct paca_struct *ppaca = &paca[cpu ^ 1];

	/* Only sleep if the other thread is not idle */
	if (!(ppaca->lppaca.idle)) {
	local_irq_disable();

	/*
	* We are about to sleep the thread and so wont be polling any
	* more.
	*/
	clear_thread_flag(TIF_POLLING_NRFLAG);

	/*
	* SMT dynamic mode. Cede will result in this thread going
	* dormant, if the partner thread is still doing work. Thread
	* wakes up if partner goes idle, an interrupt is presented, or
	* a prod occurs. Returning from the cede enables external
	* interrupts.
	*/
	if (!need_resched())
	cede_processor();
	else
	local_irq_enable();
	} else {
	/*
	* Give the HV an opportunity at the processor, since we are
	* not doing any work.
	*/
	poll_pending();
	}
	}

	static int pseries_dedicated_idle(void)
	{
	long oldval;
	struct paca_struct *lpaca = get_paca();
	unsigned int cpu = smp_processor_id();
	unsigned long start_snooze;
	unsigned long *smt_snooze_delay = &__get_cpu_var(smt_snooze_delay);

	while (1) {
	/*
	* Indicate to the HV that we are idle. Now would be
	* a good time to find other work to dispatch.
	*/
	lpaca->lppaca.idle = 1;

	oldval = test_and_clear_thread_flag(TIF_NEED_RESCHED);
	if (!oldval) {
	set_thread_flag(TIF_POLLING_NRFLAG);

	start_snooze = __get_tb() +
	smt_snooze_delay tb_ticks_per_usec;

	while (!need_resched() && !cpu_is_offline(cpu)) {
	ppc64_runlatch_off();

	/*
	* Go into low thread priority and possibly
	* low power mode.
	*/
	HMT_low();
	HMT_very_low();

	if (*smt_snooze_delay != 0 &&
	__get_tb() > start_snooze) {
	HMT_medium();
	dedicated_idle_sleep(cpu);
	}

	}

	HMT_medium();
	clear_thread_flag(TIF_POLLING_NRFLAG);
	} else {
	set_need_resched();
	}

	lpaca->lppaca.idle = 0;
	ppc64_runlatch_on();

	schedule();

	if (cpu_is_offline(cpu) && system_state == SYSTEM_RUNNING)
	cpu_die();
	}
	}

	static int pseries_shared_idle(void)
	{
	struct paca_struct *lpaca = get_paca();
	unsigned int cpu = smp_processor_id();

	while (1) {
	/*
	* Indicate to the HV that we are idle. Now would be
	* a good time to find other work to dispatch.
	*/
	lpaca->lppaca.idle = 1;

	while (!need_resched() && !cpu_is_offline(cpu)) {
	local_irq_disable();
	ppc64_runlatch_off();

	/*
	* Yield the processor to the hypervisor. We return if
	* an external interrupt occurs (which are driven prior
	* to returning here) or if a prod occurs from another
	* processor. When returning here, external interrupts
	* are enabled.
	*
	* Check need_resched() again with interrupts disabled
	* to avoid a race.
	*/
	if (!need_resched())
	cede_processor();
	else
	local_irq_enable();

	HMT_medium();
	}

	lpaca->lppaca.idle = 0;
	ppc64_runlatch_on();

	schedule();

	if (cpu_is_offline(cpu) && system_state == SYSTEM_RUNNING)
	cpu_die();
	}

	return 0;
	}

	struct machdep_calls __initdata pSeries_md = {
	.probe = pSeries_probe,
	.setup_arch = pSeries_setup_arch,
	.init_early = pSeries_init_early,
	.get_cpuinfo = pSeries_get_cpuinfo,
	.log_error = pSeries_log_error,
	.pcibios_fixup = pSeries_final_fixup,
	.irq_bus_setup = pSeries_irq_bus_setup,
	.restart = rtas_restart,
	.power_off = rtas_power_off,
	.halt = rtas_halt,
	.panic = rtas_os_term,
	.cpu_die = pSeries_mach_cpu_die,
	.get_boot_time = rtas_get_boot_time,
	.get_rtc_time = rtas_get_rtc_time,
	.set_rtc_time = rtas_set_rtc_time,
	.calibrate_decr = generic_calibrate_decr,
	.progress = rtas_progress,
	.check_legacy_ioport = pSeries_check_legacy_ioport,
	.system_reset_exception = pSeries_system_reset_exception,
	.machine_check_exception = pSeries_machine_check_exception,
	};