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

	unsigned long p = ((unsigned long)initial_boot_params) +
		initial_boot_params->off_dt_struct;
	int rc = 0;
	int depth = -1;

	do {
		u32 tag = *((u32 *)p);
		char *pathp;
		
		p += 4;
		if (tag == OF_DT_END_NODE) {
			depth --;
			continue;
		}
		if (tag == OF_DT_NOP)
			continue;
		if (tag == OF_DT_END)
			break;
		if (tag == OF_DT_PROP) {
			u32 sz = *((u32 *)p);
			p += 8;
			if (initial_boot_params->version < 0x10)
				p = _ALIGN(p, sz >= 8 ? 8 : 4);
			p += sz;
			p = _ALIGN(p, 4);
			continue;
		}
		if (tag != OF_DT_BEGIN_NODE) {
			printk(KERN_WARNING "Invalid tag %x scanning flattened"
			       " device tree !\n", tag);
			return -EINVAL;
		}
		depth++;
		pathp = (char *)p;
		p = _ALIGN(p + strlen(pathp) + 1, 4);
		if ((*pathp) == '/') {
			char *lp, *np;
			for (lp = NULL, np = pathp; *np; np++)
				if ((*np) == '/')
					lp = np+1;
			if (lp != NULL)
				pathp = lp;
		}
		rc = it(p, pathp, depth, data);
		if (rc != 0)
			break;		
	} while(1);

	return rc;
}

unsigned long __init of_get_flat_dt_root(void)
{
	unsigned long p = ((unsigned long)initial_boot_params) +
		initial_boot_params->off_dt_struct;

	while(*((u32 *)p) == OF_DT_NOP)
		p += 4;
	BUG_ON (*((u32 *)p) != OF_DT_BEGIN_NODE);
	p += 4;
	return _ALIGN(p + strlen((char *)p) + 1, 4);
}

/**
 * This  function can be used within scan_flattened_dt callback to get
 * access to properties
 */
void* __init of_get_flat_dt_prop(unsigned long node, const char *name,
				 unsigned long *size)
{
	unsigned long p = node;

	do {
		u32 tag = *((u32 *)p);
		u32 sz, noff;
		const char *nstr;

		p += 4;
		if (tag == OF_DT_NOP)
			continue;
		if (tag != OF_DT_PROP)
			return NULL;

		sz = *((u32 *)p);
		noff = *((u32 *)(p + 4));
		p += 8;
		if (initial_boot_params->version < 0x10)
			p = _ALIGN(p, sz >= 8 ? 8 : 4);

		nstr = find_flat_dt_string(noff);
		if (nstr == NULL) {
			printk(KERN_WARNING "Can't find property index"
			       " name !\n");
			return NULL;
		}
		if (strcmp(name, nstr) == 0) {
			if (size)
				*size = sz;
			return (void *)p;
		}
		p += sz;
		p = _ALIGN(p, 4);
	} while(1);
}

int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
{
	const char* cp;
	unsigned long cplen, l;

	cp = of_get_flat_dt_prop(node, "compatible", &cplen);
	if (cp == NULL)
		return 0;
	while (cplen > 0) {
		if (strncasecmp(cp, compat, strlen(compat)) == 0)
			return 1;
		l = strlen(cp) + 1;
		cp += l;
		cplen -= l;
	}

	return 0;
}

static void *__init unflatten_dt_alloc(unsigned long *mem, unsigned long size,
				       unsigned long align)
{
	void *res;

	*mem = _ALIGN(*mem, align);
	res = (void *)*mem;
	*mem += size;

	return res;
}

static unsigned long __init unflatten_dt_node(unsigned long mem,
					      unsigned long *p,
					      struct device_node *dad,
					      struct device_node ***allnextpp,
					      unsigned long fpsize)
{
	struct device_node *np;
	struct property *pp, **prev_pp = NULL;
	char *pathp;
	u32 tag;
	unsigned int l, allocl;
	int has_name = 0;
	int new_format = 0;

	tag = *((u32 *)(*p));
	if (tag != OF_DT_BEGIN_NODE) {
		printk("Weird tag at start of node: %x\n", tag);
		return mem;
	}
	*p += 4;
	pathp = (char *)*p;
	l = allocl = strlen(pathp) + 1;
	*p = _ALIGN(*p + l, 4);

	/* version 0x10 has a more compact unit name here instead of the full
	 * path. we accumulate the full path size using "fpsize", we'll rebuild
	 * it later. We detect this because the first character of the name is
	 * not '/'.
	 */
	if ((*pathp) != '/') {
		new_format = 1;
		if (fpsize == 0) {
			/* root node: special case. fpsize accounts for path
			 * plus terminating zero. root node only has '/', so
			 * fpsize should be 2, but we want to avoid the first
			 * level nodes to have two '/' so we use fpsize 1 here
			 */
			fpsize = 1;
			allocl = 2;
		} else {
			/* account for '/' and path size minus terminal 0
			 * already in 'l'
			 */
			fpsize += l;
			allocl = fpsize;
		}
	}


	np = unflatten_dt_alloc(&mem, sizeof(struct device_node) + allocl,
				__alignof__(struct device_node));
	if (allnextpp) {
		memset(np, 0, sizeof(*np));
		np->full_name = ((char*)np) + sizeof(struct device_node);
		if (new_format) {
			char *p = np->full_name;
			/* rebuild full path for new format */
			if (dad && dad->parent) {
				strcpy(p, dad->full_name);
#ifdef DEBUG
				if ((strlen(p) + l + 1) != allocl) {
					DBG("%s: p: %d, l: %d, a: %d\n",
					    pathp, (int)strlen(p), l, allocl);
				}
#endif
				p += strlen(p);
			}
			*(p++) = '/';
			memcpy(p, pathp, l);
		} else
			memcpy(np->full_name, pathp, l);
		prev_pp = &np->properties;
		**allnextpp = np;
		*allnextpp = &np->allnext;
		if (dad != NULL) {
			np->parent = dad;
			/* we temporarily use the next field as `last_child'*/
			if (dad->next == 0)
				dad->child = np;
			else
				dad->next->sibling = np;
			dad->next = np;
		}
		kref_init(&np->kref);
	}
	while(1) {
		u32 sz, noff;
		char *pname;

		tag = *((u32 *)(*p));
		if (tag == OF_DT_NOP) {
			*p += 4;
			continue;
		}
		if (tag != OF_DT_PROP)
			break;
		*p += 4;
		sz = *((u32 *)(*p));
		noff = *((u32 *)((*p) + 4));
		*p += 8;
		if (initial_boot_params->version < 0x10)
			*p = _ALIGN(*p, sz >= 8 ? 8 : 4);

		pname = find_flat_dt_string(noff);
		if (pname == NULL) {
			printk("Can't find property name in list !\n");
			break;
		}
		if (strcmp(pname, "name") == 0)
			has_name = 1;
		l = strlen(pname) + 1;
		pp = unflatten_dt_alloc(&mem, sizeof(struct property),
					__alignof__(struct property));
		if (allnextpp) {
			if (strcmp(pname, "linux,phandle") == 0) {
				np->node = *((u32 *)*p);
				if (np->linux_phandle == 0)
					np->linux_phandle = np->node;
			}
			if (strcmp(pname, "ibm,phandle") == 0)
				np->linux_phandle = *((u32 *)*p);
			pp->name = pname;
			pp->length = sz;
			pp->value = (void *)*p;
			*prev_pp = pp;
			prev_pp = &pp->next;
		}
		*p = _ALIGN((*p) + sz, 4);
	}
	/* with version 0x10 we may not have the name property, recreate
	 * it here from the unit name if absent
	 */
	if (!has_name) {
		char *p = pathp, *ps = pathp, *pa = NULL;
		int sz;

		while (*p) {
			if ((*p) == '@')
				pa = p;
			if ((*p) == '/')
				ps = p + 1;
			p++;
		}
		if (pa < ps)
			pa = p;
		sz = (pa - ps) + 1;
		pp = unflatten_dt_alloc(&mem, sizeof(struct property) + sz,
					__alignof__(struct property));
		if (allnextpp) {
			pp->name = "name";
			pp->length = sz;
			pp->value = (unsigned char *)(pp + 1);
			*prev_pp = pp;
			prev_pp = &pp->next;
			memcpy(pp->value, ps, sz - 1);
			((char *)pp->value)[sz - 1] = 0;
			DBG("fixed up name for %s -> %s\n", pathp, pp->value);
		}
	}
	if (allnextpp) {
		*prev_pp = NULL;
		np->name = get_property(np, "name", NULL);
		np->type = get_property(np, "device_type", NULL);

		if (!np->name)
			np->name = "<NULL>";
		if (!np->type)
			np->type = "<NULL>";
	}
	while (tag == OF_DT_BEGIN_NODE) {
		mem = unflatten_dt_node(mem, p, np, allnextpp, fpsize);
		tag = *((u32 *)(*p));
	}
	if (tag != OF_DT_END_NODE) {
		printk("Weird tag at end of node: %x\n", tag);
		return mem;
	}
	*p += 4;
	return mem;
}


/**
 * unflattens the device-tree passed by the firmware, creating the
 * tree of struct device_node. It also fills the "name" and "type"
 * pointers of the nodes so the normal device-tree walking functions
 * can be used (this used to be done by finish_device_tree)
 */
void __init unflatten_device_tree(void)
{
	unsigned long start, mem, size;
	struct device_node **allnextp = &allnodes;

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

	/* First pass, scan for size */
	start = ((unsigned long)initial_boot_params) +
		initial_boot_params->off_dt_struct;
	size = unflatten_dt_node(0, &start, NULL, NULL, 0);
	size = (size | 3) + 1;

	DBG("  size is %lx, allocating...\n", size);

	/* Allocate memory for the expanded device tree */
	mem = lmb_alloc(size + 4, __alignof__(struct device_node));
	mem = (unsigned long) __va(mem);

	((u32 *)mem)[size / 4] = 0xdeadbeef;

	DBG("  unflattening %lx...\n", mem);

	/* Second pass, do actual unflattening */
	start = ((unsigned long)initial_boot_params) +
		initial_boot_params->off_dt_struct;
	unflatten_dt_node(mem, &start, NULL, &allnextp, 0);
	if (*((u32 *)start) != OF_DT_END)
		printk(KERN_WARNING "Weird tag at end of tree: %08x\n", *((u32 *)start));
	if (((u32 *)mem)[size / 4] != 0xdeadbeef)
		printk(KERN_WARNING "End of tree marker overwritten: %08x\n",
		       ((u32 *)mem)[size / 4] );
	*allnextp = NULL;

	/* Get pointer to OF "/chosen" node for use everywhere */
	of_chosen = of_find_node_by_path("/chosen");
	if (of_chosen == NULL)
		of_chosen = of_find_node_by_path("/chosen@0");

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

/*
 * ibm,pa-features is a per-cpu property that contains a string of
 * attribute descriptors, each of which has a 2 byte header plus up
 * to 254 bytes worth of processor attribute bits.  First header
 * byte specifies the number of bytes following the header.
 * Second header byte is an "attribute-specifier" type, of which
 * zero is the only currently-defined value.
 * Implementation:  Pass in the byte and bit offset for the feature
 * that we are interested in.  The function will return -1 if the
 * pa-features property is missing, or a 1/0 to indicate if the feature
 * is supported/not supported.  Note that the bit numbers are
 * big-endian to match the definition in PAPR.
 */
static struct ibm_pa_feature {
	unsigned long	cpu_features;	/* CPU_FTR_xxx bit */
	unsigned int	cpu_user_ftrs;	/* PPC_FEATURE_xxx bit */
	unsigned char	pabyte;		/* byte number in ibm,pa-features */
	unsigned char	pabit;		/* bit number (big-endian) */
	unsigned char	invert;		/* if 1, pa bit set => clear feature */
} ibm_pa_features[] __initdata = {
	{0, PPC_FEATURE_HAS_MMU,	0, 0, 0},
	{0, PPC_FEATURE_HAS_FPU,	0, 1, 0},
	{CPU_FTR_SLB, 0,		0, 2, 0},
	{CPU_FTR_CTRL, 0,		0, 3, 0},
	{CPU_FTR_NOEXECUTE, 0,		0, 6, 0},
	{CPU_FTR_NODSISRALIGN, 0,	1, 1, 1},
	{CPU_FTR_CI_LARGE_PAGE, 0,	1, 2, 0},
};

static void __init check_cpu_pa_features(unsigned long node)
{
	unsigned char *pa_ftrs;
	unsigned long len, tablelen, i, bit;

	pa_ftrs = of_get_flat_dt_prop(node, "ibm,pa-features", &tablelen);
	if (pa_ftrs == NULL)
		return;

	/* find descriptor with type == 0 */
	for (;;) {
		if (tablelen < 3)
			return;
		len = 2 + pa_ftrs[0];
		if (tablelen < len)
			return;		/* descriptor 0 not found */
		if (pa_ftrs[1] == 0)
			break;
		tablelen -= len;
		pa_ftrs += len;
	}

	/* loop over bits we know about */
	for (i = 0; i < ARRAY_SIZE(ibm_pa_features); ++i) {
		struct ibm_pa_feature *fp = &ibm_pa_features[i];

		if (fp->pabyte >= pa_ftrs[0])
			continue;
		bit = (pa_ftrs[2 + fp->pabyte] >> (7 - fp->pabit)) & 1;
		if (bit ^ fp->invert) {
			cur_cpu_spec->cpu_features |= fp->cpu_features;
			cur_cpu_spec->cpu_user_features |= fp->cpu_user_ftrs;
		} else {
			cur_cpu_spec->cpu_features &= ~fp->cpu_features;
			cur_cpu_spec->cpu_user_features &= ~fp->cpu_user_ftrs;
		}
	}
}

static int __init early_init_dt_scan_cpus(unsigned long node,
					  const char *uname, int depth,
					  void *data)
{
	static int logical_cpuid = 0;
	char *type = of_get_flat_dt_prop(node, "device_type", NULL);
#ifdef CONFIG_ALTIVEC
	u32 *prop;
#endif
	u32 *intserv;
	int i, nthreads;
	unsigned long len;
	int found = 0;

	/* We are scanning "cpu" nodes only */
	if (type == NULL || strcmp(type, "cpu") != 0)
		return 0;

	/* Get physical cpuid */
	intserv = of_get_flat_dt_prop(node, "ibm,ppc-interrupt-server#s", &len);
	if (intserv) {
		nthreads = len / sizeof(int);
	} else {
		intserv = of_get_flat_dt_prop(node, "reg", NULL);
		nthreads = 1;
	}

	/*
	 * Now see if any of these threads match our boot cpu.
	 * NOTE: This must match the parsing done in smp_setup_cpu_maps.
	 */
	for (i = 0; i < nthreads; i++) {
		/*
		 * version 2 of the kexec param format adds the phys cpuid of
		 * booted proc.
		 */
		if (initial_boot_params && initial_boot_params->version >= 2) {
			if (intserv[i] ==
					initial_boot_params->boot_cpuid_phys) {
				found = 1;
				break;
			}
		} else {
			/*
			 * Check if it's the boot-cpu, set it's hw index now,
			 * unfortunately this format did not support booting
			 * off secondary threads.
			 */
			if (of_get_flat_dt_prop(node,
					"linux,boot-cpu", NULL) != NULL) {
				found = 1;
				break;
			}
		}

#ifdef CONFIG_SMP
		/* logical cpu id is always 0 on UP kernels */
		logical_cpuid++;
#endif
	}

	if (found) {
		DBG("boot cpu: logical %d physical %d\n", logical_cpuid,
			intserv[i]);
		boot_cpuid = logical_cpuid;
		set_hard_smp_processor_id(boot_cpuid, intserv[i]);
	}

#ifdef CONFIG_ALTIVEC
	/* Check if we have a VMX and eventually update CPU features */
	prop = (u32 *)of_get_flat_dt_prop(node, "ibm,vmx", NULL);
	if (prop && (*prop) > 0) {
		cur_cpu_spec->cpu_features |= CPU_FTR_ALTIVEC;
		cur_cpu_spec->cpu_user_features |= PPC_FEATURE_HAS_ALTIVEC;
	}

	/* Same goes for Apple's "altivec" property */
	prop = (u32 *)of_get_flat_dt_prop(node, "altivec", NULL);
	if (prop) {
		cur_cpu_spec->cpu_features |= CPU_FTR_ALTIVEC;
		cur_cpu_spec->cpu_user_features |= PPC_FEATURE_HAS_ALTIVEC;
	}
#endif /* CONFIG_ALTIVEC */

	check_cpu_pa_features(node);

#ifdef CONFIG_PPC_PSERIES