cbe_regs.c

/*
 * cbe_regs.c
 *
 * Accessor routines for the various MMIO register blocks of the CBE
 *
 * (c) 2006 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp.
 */


#include <linux/config.h>
#include <linux/percpu.h>
#include <linux/types.h>

#include <asm/io.h>
#include <asm/pgtable.h>
#include <asm/prom.h>
#include <asm/ptrace.h>

#include "cbe_regs.h"

#define MAX_CBE		2

/*
 * Current implementation uses "cpu" nodes. We build our own mapping
 * array of cpu numbers to cpu nodes locally for now to allow interrupt
 * time code to have a fast path rather than call of_get_cpu_node(). If
 * we implement cpu hotplug, we'll have to install an appropriate norifier
 * in order to release references to the cpu going away
 */
static struct cbe_regs_map
{
	struct device_node *cpu_node;
	struct cbe_pmd_regs __iomem *pmd_regs;
	struct cbe_iic_regs __iomem *iic_regs;
} cbe_regs_maps[MAX_CBE];
static int cbe_regs_map_count;

static struct cbe_thread_map
{
	struct device_node *cpu_node;
	struct cbe_regs_map *regs;
} cbe_thread_map[NR_CPUS];

static struct cbe_regs_map *cbe_find_map(struct device_node *np)
{
	int i;

	for (i = 0; i < cbe_regs_map_count; i++)
		if (cbe_regs_maps[i].cpu_node == np)
			return &cbe_regs_maps[i];
	return NULL;
}

struct cbe_pmd_regs __iomem *cbe_get_pmd_regs(struct device_node *np)
{
	struct cbe_regs_map *map = cbe_find_map(np);
	if (map == NULL)
		return NULL;
	return map->pmd_regs;
}

struct cbe_pmd_regs __iomem *cbe_get_cpu_pmd_regs(int cpu)
{
	struct cbe_regs_map *map = cbe_thread_map[cpu].regs;
	if (map == NULL)
		return NULL;
	return map->pmd_regs;
}


struct cbe_iic_regs __iomem *cbe_get_iic_regs(struct device_node *np)
{
	struct cbe_regs_map *map = cbe_find_map(np);
	if (map == NULL)
		return NULL;
	return map->iic_regs;
}
struct cbe_iic_regs __iomem *cbe_get_cpu_iic_regs(int cpu)
{
	struct cbe_regs_map *map = cbe_thread_map[cpu].regs;
	if (map == NULL)
		return NULL;
	return map->iic_regs;
}

void __init cbe_regs_init(void)
{
	int i;
	struct device_node *cpu;

	/* Build local fast map of CPUs */
	for_each_cpu(i)
		cbe_thread_map[i].cpu_node = of_get_cpu_node(i, NULL);

	/* Find maps for each device tree CPU */
	for_each_node_by_type(cpu, "cpu") {
		struct cbe_regs_map *map = &cbe_regs_maps[cbe_regs_map_count++];

		/* That hack must die die die ! */
		struct address_prop {
			unsigned long address;
			unsigned int len;
		} __attribute__((packed)) *prop;


		if (cbe_regs_map_count > MAX_CBE) {
			printk(KERN_ERR "cbe_regs: More BE chips than supported"
			       "!\n");
			cbe_regs_map_count--;
			return;
		}
		map->cpu_node = cpu;
		for_each_cpu(i)
			if (cbe_thread_map[i].cpu_node == cpu)
				cbe_thread_map[i].regs = map;

		prop = (struct address_prop *)get_property(cpu, "pervasive",
							   NULL);
		if (prop != NULL)
			map->pmd_regs = ioremap(prop->address, prop->len);

		prop = (struct address_prop *)get_property(cpu, "iic",
							   NULL);
		if (prop != NULL)
			map->iic_regs = ioremap(prop->address, prop->len);
	}
}