prom.c

来自「LINUX 2.6.17.4的源码」· C语言 代码 · 共 2,082 行 · 第 1/4 页

/*
 * Procedures for creating, accessing and interpreting the device tree.
 *
 * 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

#include <stdarg.h>
#include <linux/config.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/stringify.h>
#include <linux/delay.h>
#include <linux/initrd.h>
#include <linux/bitops.h>
#include <linux/module.h>
#include <linux/kexec.h>

#include <asm/prom.h>
#include <asm/rtas.h>
#include <asm/lmb.h>
#include <asm/page.h>
#include <asm/processor.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <asm/kdump.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>
#include <asm/pSeries_reconfig.h>
#include <asm/pci-bridge.h>

#ifdef DEBUG
#define DBG(fmt...) printk(KERN_ERR fmt)
#else
#define DBG(fmt...)
#endif


static int __initdata dt_root_addr_cells;
static int __initdata dt_root_size_cells;

#ifdef CONFIG_PPC64
int __initdata iommu_is_off;
int __initdata iommu_force_on;
unsigned long tce_alloc_start, tce_alloc_end;
#endif

typedef u32 cell_t;

#if 0
static struct boot_param_header *initial_boot_params __initdata;
#else
struct boot_param_header *initial_boot_params;
#endif

static struct device_node *allnodes = NULL;

/* use when traversing tree through the allnext, child, sibling,
 * or parent members of struct device_node.
 */
static DEFINE_RWLOCK(devtree_lock);

/* export that to outside world */
struct device_node *of_chosen;

struct device_node *dflt_interrupt_controller;
int num_interrupt_controllers;

/*
 * Wrapper for allocating memory for various data that needs to be
 * attached to device nodes as they are processed at boot or when
 * added to the device tree later (e.g. DLPAR).  At boot there is
 * already a region reserved so we just increment *mem_start by size;
 * otherwise we call kmalloc.
 */
static void * prom_alloc(unsigned long size, unsigned long *mem_start)
{
	unsigned long tmp;

	if (!mem_start)
		return kmalloc(size, GFP_KERNEL);

	tmp = *mem_start;
	*mem_start += size;
	return (void *)tmp;
}

/*
 * Find the device_node with a given phandle.
 */
static struct device_node * find_phandle(phandle ph)
{
	struct device_node *np;

	for (np = allnodes; np != 0; np = np->allnext)
		if (np->linux_phandle == ph)
			return np;
	return NULL;
}

/*
 * Find the interrupt parent of a node.
 */
static struct device_node * __devinit intr_parent(struct device_node *p)
{
	phandle *parp;

	parp = (phandle *) get_property(p, "interrupt-parent", NULL);
	if (parp == NULL)
		return p->parent;
	p = find_phandle(*parp);
	if (p != NULL)
		return p;
	/*
	 * On a powermac booted with BootX, we don't get to know the
	 * phandles for any nodes, so find_phandle will return NULL.
	 * Fortunately these machines only have one interrupt controller
	 * so there isn't in fact any ambiguity.  -- paulus
	 */
	if (num_interrupt_controllers == 1)
		p = dflt_interrupt_controller;
	return p;
}

/*
 * Find out the size of each entry of the interrupts property
 * for a node.
 */
int __devinit prom_n_intr_cells(struct device_node *np)
{
	struct device_node *p;
	unsigned int *icp;

	for (p = np; (p = intr_parent(p)) != NULL; ) {
		icp = (unsigned int *)
			get_property(p, "#interrupt-cells", NULL);
		if (icp != NULL)
			return *icp;
		if (get_property(p, "interrupt-controller", NULL) != NULL
		    || get_property(p, "interrupt-map", NULL) != NULL) {
			printk("oops, node %s doesn't have #interrupt-cells\n",
			       p->full_name);
			return 1;
		}
	}
#ifdef DEBUG_IRQ
	printk("prom_n_intr_cells failed for %s\n", np->full_name);
#endif
	return 1;
}

/*
 * Map an interrupt from a device up to the platform interrupt
 * descriptor.
 */
static int __devinit map_interrupt(unsigned int **irq, struct device_node **ictrler,
				   struct device_node *np, unsigned int *ints,
				   int nintrc)
{
	struct device_node *p, *ipar;
	unsigned int *imap, *imask, *ip;
	int i, imaplen, match;
	int newintrc = 0, newaddrc = 0;
	unsigned int *reg;
	int naddrc;

	reg = (unsigned int *) get_property(np, "reg", NULL);
	naddrc = prom_n_addr_cells(np);
	p = intr_parent(np);
	while (p != NULL) {
		if (get_property(p, "interrupt-controller", NULL) != NULL)
			/* this node is an interrupt controller, stop here */
			break;
		imap = (unsigned int *)
			get_property(p, "interrupt-map", &imaplen);
		if (imap == NULL) {
			p = intr_parent(p);
			continue;
		}
		imask = (unsigned int *)
			get_property(p, "interrupt-map-mask", NULL);
		if (imask == NULL) {
			printk("oops, %s has interrupt-map but no mask\n",
			       p->full_name);
			return 0;
		}
		imaplen /= sizeof(unsigned int);
		match = 0;
		ipar = NULL;
		while (imaplen > 0 && !match) {
			/* check the child-interrupt field */
			match = 1;
			for (i = 0; i < naddrc && match; ++i)
				match = ((reg[i] ^ imap[i]) & imask[i]) == 0;
			for (; i < naddrc + nintrc && match; ++i)
				match = ((ints[i-naddrc] ^ imap[i]) & imask[i]) == 0;
			imap += naddrc + nintrc;
			imaplen -= naddrc + nintrc;
			/* grab the interrupt parent */
			ipar = find_phandle((phandle) *imap++);
			--imaplen;
			if (ipar == NULL && num_interrupt_controllers == 1)
				/* cope with BootX not giving us phandles */
				ipar = dflt_interrupt_controller;
			if (ipar == NULL) {
				printk("oops, no int parent %x in map of %s\n",
				       imap[-1], p->full_name);
				return 0;
			}
			/* find the parent's # addr and intr cells */
			ip = (unsigned int *)
				get_property(ipar, "#interrupt-cells", NULL);
			if (ip == NULL) {
				printk("oops, no #interrupt-cells on %s\n",
				       ipar->full_name);
				return 0;
			}
			newintrc = *ip;
			ip = (unsigned int *)
				get_property(ipar, "#address-cells", NULL);
			newaddrc = (ip == NULL)? 0: *ip;
			imap += newaddrc + newintrc;
			imaplen -= newaddrc + newintrc;
		}
		if (imaplen < 0) {
			printk("oops, error decoding int-map on %s, len=%d\n",
			       p->full_name, imaplen);
			return 0;
		}
		if (!match) {
#ifdef DEBUG_IRQ
			printk("oops, no match in %s int-map for %s\n",
			       p->full_name, np->full_name);
#endif
			return 0;
		}
		p = ipar;
		naddrc = newaddrc;
		nintrc = newintrc;
		ints = imap - nintrc;
		reg = ints - naddrc;
	}
	if (p == NULL) {
#ifdef DEBUG_IRQ
		printk("hmmm, int tree for %s doesn't have ctrler\n",
		       np->full_name);
#endif
		return 0;
	}
	*irq = ints;
	*ictrler = p;
	return nintrc;
}

static unsigned char map_isa_senses[4] = {
	IRQ_SENSE_LEVEL | IRQ_POLARITY_NEGATIVE,
	IRQ_SENSE_LEVEL | IRQ_POLARITY_POSITIVE,
	IRQ_SENSE_EDGE  | IRQ_POLARITY_NEGATIVE,
	IRQ_SENSE_EDGE  | IRQ_POLARITY_POSITIVE
};

static unsigned char map_mpic_senses[4] = {
	IRQ_SENSE_EDGE  | IRQ_POLARITY_POSITIVE,
	IRQ_SENSE_LEVEL | IRQ_POLARITY_NEGATIVE,
	/* 2 seems to be used for the 8259 cascade... */
	IRQ_SENSE_LEVEL | IRQ_POLARITY_POSITIVE,
	IRQ_SENSE_EDGE  | IRQ_POLARITY_NEGATIVE,
};

static int __devinit finish_node_interrupts(struct device_node *np,
					    unsigned long *mem_start,
					    int measure_only)
{
	unsigned int *ints;
	int intlen, intrcells, intrcount;
	int i, j, n, sense;
	unsigned int *irq, virq;
	struct device_node *ic;
	int trace = 0;

	//#define TRACE(fmt...) do { if (trace) { printk(fmt); mdelay(1000); } } while(0)
#define TRACE(fmt...)

	if (!strcmp(np->name, "smu-doorbell"))
		trace = 1;

	TRACE("Finishing SMU doorbell ! num_interrupt_controllers = %d\n",
	      num_interrupt_controllers);

	if (num_interrupt_controllers == 0) {
		/*
		 * Old machines just have a list of interrupt numbers
		 * and no interrupt-controller nodes.
		 */
		ints = (unsigned int *) get_property(np, "AAPL,interrupts",
						     &intlen);
		/* XXX old interpret_pci_props looked in parent too */
		/* XXX old interpret_macio_props looked for interrupts
		   before AAPL,interrupts */
		if (ints == NULL)
			ints = (unsigned int *) get_property(np, "interrupts",
							     &intlen);
		if (ints == NULL)
			return 0;

		np->n_intrs = intlen / sizeof(unsigned int);
		np->intrs = prom_alloc(np->n_intrs * sizeof(np->intrs[0]),
				       mem_start);
		if (!np->intrs)
			return -ENOMEM;
		if (measure_only)
			return 0;

		for (i = 0; i < np->n_intrs; ++i) {
			np->intrs[i].line = *ints++;
			np->intrs[i].sense = IRQ_SENSE_LEVEL
				| IRQ_POLARITY_NEGATIVE;
		}
		return 0;
	}

	ints = (unsigned int *) get_property(np, "interrupts", &intlen);
	TRACE("ints=%p, intlen=%d\n", ints, intlen);
	if (ints == NULL)
		return 0;
	intrcells = prom_n_intr_cells(np);
	intlen /= intrcells * sizeof(unsigned int);
	TRACE("intrcells=%d, new intlen=%d\n", intrcells, intlen);
	np->intrs = prom_alloc(intlen * sizeof(*(np->intrs)), mem_start);
	if (!np->intrs)
		return -ENOMEM;

	if (measure_only)
		return 0;

	intrcount = 0;
	for (i = 0; i < intlen; ++i, ints += intrcells) {
		n = map_interrupt(&irq, &ic, np, ints, intrcells);
		TRACE("map, irq=%d, ic=%p, n=%d\n", irq, ic, n);
		if (n <= 0)
			continue;

		/* don't map IRQ numbers under a cascaded 8259 controller */
		if (ic && device_is_compatible(ic, "chrp,iic")) {
			np->intrs[intrcount].line = irq[0];
			sense = (n > 1)? (irq[1] & 3): 3;
			np->intrs[intrcount].sense = map_isa_senses[sense];
		} else {
			virq = virt_irq_create_mapping(irq[0]);
			TRACE("virq=%d\n", virq);
#ifdef CONFIG_PPC64
			if (virq == NO_IRQ) {
				printk(KERN_CRIT "Could not allocate interrupt"
				       " number for %s\n", np->full_name);
				continue;
			}
#endif
			np->intrs[intrcount].line = irq_offset_up(virq);
			sense = (n > 1)? (irq[1] & 3): 1;

			/* Apple uses bits in there in a different way, let's
			 * only keep the real sense bit on macs
			 */
			if (machine_is(powermac))
				sense &= 0x1;
			np->intrs[intrcount].sense = map_mpic_senses[sense];
		}

#ifdef CONFIG_PPC64
		/* We offset irq numbers for the u3 MPIC by 128 in PowerMac */
		if (machine_is(powermac) && ic && ic->parent) {
			char *name = get_property(ic->parent, "name", NULL);
			if (name && !strcmp(name, "u3"))
				np->intrs[intrcount].line += 128;
			else if (!(name && (!strcmp(name, "mac-io") ||
					    !strcmp(name, "u4"))))
				/* ignore other cascaded controllers, such as
				   the k2-sata-root */
				break;
		}
#endif /* CONFIG_PPC64 */
		if (n > 2) {
			printk("hmmm, got %d intr cells for %s:", n,
			       np->full_name);
			for (j = 0; j < n; ++j)
				printk(" %d", irq[j]);
			printk("\n");
		}
		++intrcount;
	}
	np->n_intrs = intrcount;

	return 0;
}

static int __devinit finish_node(struct device_node *np,
				 unsigned long *mem_start,
				 int measure_only)
{
	struct device_node *child;
	int rc = 0;

	rc = finish_node_interrupts(np, mem_start, measure_only);
	if (rc)
		goto out;

	for (child = np->child; child != NULL; child = child->sibling) {
		rc = finish_node(child, mem_start, measure_only);
		if (rc)
			goto out;
	}
out:
	return rc;
}

static void __init scan_interrupt_controllers(void)
{
	struct device_node *np;
	int n = 0;
	char *name, *ic;
	int iclen;

	for (np = allnodes; np != NULL; np = np->allnext) {
		ic = get_property(np, "interrupt-controller", &iclen);
		name = get_property(np, "name", NULL);
		/* checking iclen makes sure we don't get a false
		   match on /chosen.interrupt_controller */
		if ((name != NULL
		     && strcmp(name, "interrupt-controller") == 0)
		    || (ic != NULL && iclen == 0
			&& strcmp(name, "AppleKiwi"))) {
			if (n == 0)
				dflt_interrupt_controller = np;
			++n;
		}
	}
	num_interrupt_controllers = n;
}

/**
 * finish_device_tree is called once things are running normally
 * (i.e. with text and data mapped to the address they were linked at).
 * It traverses the device tree and fills in some of the additional,
 * fields in each node like {n_}addrs and {n_}intrs, the virt interrupt
 * mapping is also initialized at this point.
 */
void __init finish_device_tree(void)
{
	unsigned long start, end, size = 0;

	DBG(" -> finish_device_tree\n");

#ifdef CONFIG_PPC64
	/* Initialize virtual IRQ map */
	virt_irq_init();
#endif
	scan_interrupt_controllers();

	/*
	 * Finish device-tree (pre-parsing some properties etc...)
	 * We do this in 2 passes. One with "measure_only" set, which
	 * will only measure the amount of memory needed, then we can
	 * allocate that memory, and call finish_node again. However,
	 * we must be careful as most routines will fail nowadays when
	 * prom_alloc() returns 0, so we must make sure our first pass
	 * doesn't start at 0. We pre-initialize size to 16 for that
	 * reason and then remove those additional 16 bytes
	 */
	size = 16;
	finish_node(allnodes, &size, 1);
	size -= 16;

	if (0 == size)
		end = start = 0;
	else
		end = start = (unsigned long)__va(lmb_alloc(size, 128));

	finish_node(allnodes, &end, 0);
	BUG_ON(end != start + size);

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

static inline char *find_flat_dt_string(u32 offset)
{
	return ((char *)initial_boot_params) +
		initial_boot_params->off_dt_strings + offset;
}

/**
 * This function is used to scan the flattened device-tree, it is
 * used to extract the memory informations at boot before we can
 * unflatten the tree
 */
int __init of_scan_flat_dt(int (*it)(unsigned long node,
				     const char *uname, int depth,
				     void *data),
			   void *data)
{