prom.c

底层驱动开发

	DBG("Command line is: %s\n", cmd_line);

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


static int __init early_init_dt_scan_cpus(unsigned long node,
					  const char *uname, int depth, void *data)
{
	char *type = get_flat_dt_prop(node, "device_type", NULL);
	u32 *prop;
	unsigned long size;

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

	/* On LPAR, look for the first ibm,pft-size property for the  hash table size
	 */
	if (systemcfg->platform == PLATFORM_PSERIES_LPAR && ppc64_pft_size == 0) {
		u32 *pft_size;
		pft_size = (u32 *)get_flat_dt_prop(node, "ibm,pft-size", NULL);
		if (pft_size != NULL) {
			/* pft_size[0] is the NUMA CEC cookie */
			ppc64_pft_size = pft_size[1];
		}
	}

	if (initial_boot_params && initial_boot_params->version >= 2) {
		/* version 2 of the kexec param format adds the phys cpuid
		 * of booted proc.
		 */
		boot_cpuid_phys = initial_boot_params->boot_cpuid_phys;
		boot_cpuid = 0;
	} else {
		/* Check if it's the boot-cpu, set it's hw index in paca now */
		if (get_flat_dt_prop(node, "linux,boot-cpu", NULL) != NULL) {
			u32 *prop = get_flat_dt_prop(node, "reg", NULL);
			set_hard_smp_processor_id(0, prop == NULL ? 0 : *prop);
			boot_cpuid_phys = get_hard_smp_processor_id(0);
		}
	}

#ifdef CONFIG_ALTIVEC
	/* Check if we have a VMX and eventually update CPU features */
	prop = (u32 *)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 *)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 for an SMT capable CPU and set the CPU feature. We do
	 * this by looking at the size of the ibm,ppc-interrupt-server#s
	 * property
	 */
	prop = (u32 *)get_flat_dt_prop(node, "ibm,ppc-interrupt-server#s",
				       &size);
	cur_cpu_spec->cpu_features &= ~CPU_FTR_SMT;
	if (prop && ((size / sizeof(u32)) > 1))
		cur_cpu_spec->cpu_features |= CPU_FTR_SMT;

	return 0;
}

static int __init early_init_dt_scan_chosen(unsigned long node,
					    const char *uname, int depth, void *data)
{
	u32 *prop;
	u64 *prop64;
	extern unsigned long memory_limit, tce_alloc_start, tce_alloc_end;

	DBG("search \"chosen\", depth: %d, uname: %s\n", depth, uname);

	if (depth != 1 || strcmp(uname, "chosen") != 0)
		return 0;

	/* get platform type */
	prop = (u32 *)get_flat_dt_prop(node, "linux,platform", NULL);
	if (prop == NULL)
		return 0;
	systemcfg->platform = *prop;

	/* check if iommu is forced on or off */
	if (get_flat_dt_prop(node, "linux,iommu-off", NULL) != NULL)
		iommu_is_off = 1;
	if (get_flat_dt_prop(node, "linux,iommu-force-on", NULL) != NULL)
		iommu_force_on = 1;

 	prop64 = (u64*)get_flat_dt_prop(node, "linux,memory-limit", NULL);
 	if (prop64)
 		memory_limit = *prop64;

 	prop64 = (u64*)get_flat_dt_prop(node, "linux,tce-alloc-start", NULL);
 	if (prop64)
 		tce_alloc_start = *prop64;

 	prop64 = (u64*)get_flat_dt_prop(node, "linux,tce-alloc-end", NULL);
 	if (prop64)
 		tce_alloc_end = *prop64;

#ifdef CONFIG_PPC_RTAS
	/* To help early debugging via the front panel, we retreive a minimal
	 * set of RTAS infos now if available
	 */
	{
		u64 *basep, *entryp;

		basep = (u64*)get_flat_dt_prop(node, "linux,rtas-base", NULL);
		entryp = (u64*)get_flat_dt_prop(node, "linux,rtas-entry", NULL);
		prop = (u32*)get_flat_dt_prop(node, "linux,rtas-size", NULL);
		if (basep && entryp && prop) {
			rtas.base = *basep;
			rtas.entry = *entryp;
			rtas.size = *prop;
		}
	}
#endif /* CONFIG_PPC_RTAS */

	/* break now */
	return 1;
}

static int __init early_init_dt_scan_root(unsigned long node,
					  const char *uname, int depth, void *data)
{
	u32 *prop;

	if (depth != 0)
		return 0;

	prop = (u32 *)get_flat_dt_prop(node, "#size-cells", NULL);
	dt_root_size_cells = (prop == NULL) ? 1 : *prop;
	DBG("dt_root_size_cells = %x\n", dt_root_size_cells);

	prop = (u32 *)get_flat_dt_prop(node, "#address-cells", NULL);
	dt_root_addr_cells = (prop == NULL) ? 2 : *prop;
	DBG("dt_root_addr_cells = %x\n", dt_root_addr_cells);
	
	/* break now */
	return 1;
}

static unsigned long __init dt_mem_next_cell(int s, cell_t **cellp)
{
	cell_t *p = *cellp;
	unsigned long r = 0;

	/* Ignore more than 2 cells */
	while (s > 2) {
		p++;
		s--;
	}
	while (s) {
		r <<= 32;
		r |= *(p++);
		s--;
	}

	*cellp = p;
	return r;
}


static int __init early_init_dt_scan_memory(unsigned long node,
					    const char *uname, int depth, void *data)
{
	char *type = get_flat_dt_prop(node, "device_type", NULL);
	cell_t *reg, *endp;
	unsigned long l;

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

	reg = (cell_t *)get_flat_dt_prop(node, "reg", &l);
	if (reg == NULL)
		return 0;

	endp = reg + (l / sizeof(cell_t));

	DBG("memory scan node %s ..., reg size %ld, data: %x %x %x %x, ...\n",
	    uname, l, reg[0], reg[1], reg[2], reg[3]);

	while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
		unsigned long base, size;

		base = dt_mem_next_cell(dt_root_addr_cells, &reg);
		size = dt_mem_next_cell(dt_root_size_cells, &reg);

		if (size == 0)
			continue;
		DBG(" - %lx ,  %lx\n", base, size);
		if (iommu_is_off) {
			if (base >= 0x80000000ul)
				continue;
			if ((base + size) > 0x80000000ul)
				size = 0x80000000ul - base;
		}
		lmb_add(base, size);
	}
	return 0;
}

static void __init early_reserve_mem(void)
{
	u64 base, size;
	u64 *reserve_map = (u64 *)(((unsigned long)initial_boot_params) +
				   initial_boot_params->off_mem_rsvmap);
	while (1) {
		base = *(reserve_map++);
		size = *(reserve_map++);
		if (size == 0)
			break;
		DBG("reserving: %lx -> %lx\n", base, size);
		lmb_reserve(base, size);
	}

#if 0
	DBG("memory reserved, lmbs :\n");
      	lmb_dump_all();
#endif
}

void __init early_init_devtree(void *params)
{
	DBG(" -> early_init_devtree()\n");

	/* Setup flat device-tree pointer */
	initial_boot_params = params;

	/* By default, hash size is not set */
	ppc64_pft_size = 0;

	/* Retreive various informations from the /chosen node of the
	 * device-tree, including the platform type, initrd location and
	 * size, TCE reserve, and more ...
	 */
	scan_flat_dt(early_init_dt_scan_chosen, NULL);

	/* Scan memory nodes and rebuild LMBs */
	lmb_init();
	scan_flat_dt(early_init_dt_scan_root, NULL);
	scan_flat_dt(early_init_dt_scan_memory, NULL);
	lmb_enforce_memory_limit();
	lmb_analyze();
	systemcfg->physicalMemorySize = lmb_phys_mem_size();
	lmb_reserve(0, __pa(klimit));

	DBG("Phys. mem: %lx\n", systemcfg->physicalMemorySize);

	/* Reserve LMB regions used by kernel, initrd, dt, etc... */
	early_reserve_mem();

	DBG("Scanning CPUs ...\n");

	/* Retreive hash table size from flattened tree plus other
	 * CPU related informations (altivec support, boot CPU ID, ...)
	 */
	scan_flat_dt(early_init_dt_scan_cpus, NULL);

	/* If hash size wasn't obtained above, we calculate it now based on
	 * the total RAM size
	 */
	if (ppc64_pft_size == 0) {
		unsigned long rnd_mem_size, pteg_count;

		/* round mem_size up to next power of 2 */
		rnd_mem_size = 1UL << __ilog2(systemcfg->physicalMemorySize);
		if (rnd_mem_size < systemcfg->physicalMemorySize)
			rnd_mem_size <<= 1;

		/* # pages / 2 */
		pteg_count = max(rnd_mem_size >> (12 + 1), 1UL << 11);

		ppc64_pft_size = __ilog2(pteg_count << 7);
	}

	DBG("Hash pftSize: %x\n", (int)ppc64_pft_size);
	DBG(" <- early_init_devtree()\n");
}

#undef printk

int
prom_n_addr_cells(struct device_node* np)
{
	int* ip;
	do {
		if (np->parent)
			np = np->parent;
		ip = (int *) get_property(np, "#address-cells", NULL);
		if (ip != NULL)
			return *ip;
	} while (np->parent);
	/* No #address-cells property for the root node, default to 1 */
	return 1;
}

int
prom_n_size_cells(struct device_node* np)
{
	int* ip;
	do {
		if (np->parent)
			np = np->parent;
		ip = (int *) get_property(np, "#size-cells", NULL);
		if (ip != NULL)
			return *ip;
	} while (np->parent);
	/* No #size-cells property for the root node, default to 1 */
	return 1;
}

/**
 * Work out the sense (active-low level / active-high edge)
 * of each interrupt from the device tree.
 */
void __init prom_get_irq_senses(unsigned char *senses, int off, int max)
{
	struct device_node *np;
	int i, j;

	/* default to level-triggered */
	memset(senses, 1, max - off);

	for (np = allnodes; np != 0; np = np->allnext) {
		for (j = 0; j < np->n_intrs; j++) {
			i = np->intrs[j].line;
			if (i >= off && i < max)
				senses[i-off] = np->intrs[j].sense ?
					IRQ_SENSE_LEVEL | IRQ_POLARITY_NEGATIVE :
					IRQ_SENSE_EDGE | IRQ_POLARITY_POSITIVE;
		}
	}
}

/**
 * Construct and return a list of the device_nodes with a given name.
 */
struct device_node *
find_devices(const char *name)
{
	struct device_node *head, **prevp, *np;

	prevp = &head;
	for (np = allnodes; np != 0; np = np->allnext) {
		if (np->name != 0 && strcasecmp(np->name, name) == 0) {
			*prevp = np;
			prevp = &np->next;
		}
	}
	*prevp = NULL;
	return head;
}
EXPORT_SYMBOL(find_devices);

/**
 * Construct and return a list of the device_nodes with a given type.
 */
struct device_node *
find_type_devices(const char *type)
{
	struct device_node *head, **prevp, *np;

	prevp = &head;
	for (np = allnodes; np != 0; np = np->allnext) {
		if (np->type != 0 && strcasecmp(np->type, type) == 0) {
			*prevp = np;
			prevp = &np->next;
		}
	}
	*prevp = NULL;
	return head;
}
EXPORT_SYMBOL(find_type_devices);

/**
 * Returns all nodes linked together
 */
struct device_node *
find_all_nodes(void)
{
	struct device_node *head, **prevp, *np;

	prevp = &head;
	for (np = allnodes; np != 0; np = np->allnext) {
		*prevp = np;
		prevp = &np->next;
	}
	*prevp = NULL;
	return head;
}
EXPORT_SYMBOL(find_all_nodes);

/** Checks if the given "compat" string matches one of the strings in
 * the device's "compatible" property
 */
int
device_is_compatible(struct device_node *device, const char *compat)
{
	const char* cp;
	int cplen, l;

	cp = (char *) get_property(device, "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;
}
EXPORT_SYMBOL(device_is_compatible);


/**
 * Indicates whether the root node has a given value in its
 * compatible property.
 */
int
machine_is_compatible(const char *compat)
{
	struct device_node *root;
	int rc = 0;

	root = of_find_node_by_path("/");
	if (root) {
		rc = device_is_compatible(root, compat);
		of_node_put(root);
	}
	return rc;
}
EXPORT_SYMBOL(machine_is_compatible);

/**
 * Construct and return a list of the device_nodes with a given type
 * and compatible property.
 */
struct device_node *
find_compatible_devices(const char *type, const char *compat)
{
	struct device_node *head, **prevp, *np;

	prevp = &head;
	for (np = allnodes; np != 0; np = np->allnext) {
		if (type != NULL
		    && !(np->type != 0 && strcasecmp(np->type, type) == 0))
			continue;
		if (device_is_compatible(np, compat)) {
			*prevp = np;
			prevp = &np->next;
		}
	}
	*prevp = NULL;
	return head;
}
EXPORT_SYMBOL(find_compatible_devices);

/**
 * Find the device_node with a given full_name.
 */
struct device_node *
find_path_device(const char *path)
{
	struct device_node *np;

	for (np = allnodes; np != 0; np = np->allnext)
		if (np->full_name != 0 && strcasecmp(np->full_name, path) == 0)
			return np;
	return NULL;
}
EXPORT_SYMBOL(find_path_device);

/*******
 *
 * New implementation of the OF "find" APIs, return a refcounted
 * object, call of_node_put() when done.  The device tree and list
 * are protected by a rw_lock.
 *