// SPDX-License-Identifier: GPL-2.0-only
/*
 * 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/percpu.h>
#include <linux/types.h>
#include <linux/export.h>
#include <linux/of_device.h>
#include <linux/of_platform.h>
#include <linux/pgtable.h>

#include <asm/io.h>
#include <asm/prom.h>
#include <asm/ptrace.h>
#include <asm/cell-regs.h>

/*
 * 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 device_node *be_node;
        struct cbe_pmd_regs __iomem *pmd_regs;
        struct cbe_iic_regs __iomem *iic_regs;
        struct cbe_mic_tm_regs __iomem *mic_tm_regs;
        struct cbe_pmd_shadow_regs pmd_shadow_regs;
} cbe_regs_maps[MAX_CBE];
static int cbe_regs_map_count;

static struct cbe_thread_map
{
        struct device_node *cpu_node;
        struct device_node *be_node;
        struct cbe_regs_map *regs;
        unsigned int thread_id;
        unsigned int cbe_id;
} cbe_thread_map[NR_CPUS];

static cpumask_t cbe_local_mask[MAX_CBE] = { [0 ... MAX_CBE-1] = {CPU_BITS_NONE} };
static cpumask_t cbe_first_online_cpu = { CPU_BITS_NONE };

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

        if (!of_node_is_type(np, "spe")) {
                for (i = 0; i < cbe_regs_map_count; i++)
                        if (cbe_regs_maps[i].cpu_node == np ||
                            cbe_regs_maps[i].be_node == np)
                                return &cbe_regs_maps[i];
                return NULL;
        }

        if (np->data)
                return np->data;

        /* walk up path until cpu or be node was found */
        tmp_np = np;
        do {
                tmp_np = tmp_np->parent;
                /* on a correct devicetree we wont get up to root */
                BUG_ON(!tmp_np);
        } while (!of_node_is_type(tmp_np, "cpu") ||
                 !of_node_is_type(tmp_np, "be"));

        np->data = cbe_find_map(tmp_np);

        return np->data;
}

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;
}
EXPORT_SYMBOL_GPL(cbe_get_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;
}
EXPORT_SYMBOL_GPL(cbe_get_cpu_pmd_regs);

struct cbe_pmd_shadow_regs *cbe_get_pmd_shadow_regs(struct device_node *np)
{
        struct cbe_regs_map *map = cbe_find_map(np);
        if (map == NULL)
                return NULL;
        return &map->pmd_shadow_regs;
}

struct cbe_pmd_shadow_regs *cbe_get_cpu_pmd_shadow_regs(int cpu)
{
        struct cbe_regs_map *map = cbe_thread_map[cpu].regs;
        if (map == NULL)
                return NULL;
        return &map->pmd_shadow_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;
}

struct cbe_mic_tm_regs __iomem *cbe_get_mic_tm_regs(struct device_node *np)
{
        struct cbe_regs_map *map = cbe_find_map(np);
        if (map == NULL)
                return NULL;
        return map->mic_tm_regs;
}

struct cbe_mic_tm_regs __iomem *cbe_get_cpu_mic_tm_regs(int cpu)
{
        struct cbe_regs_map *map = cbe_thread_map[cpu].regs;
        if (map == NULL)
                return NULL;
        return map->mic_tm_regs;
}
EXPORT_SYMBOL_GPL(cbe_get_cpu_mic_tm_regs);

u32 cbe_get_hw_thread_id(int cpu)
{
        return cbe_thread_map[cpu].thread_id;
}
EXPORT_SYMBOL_GPL(cbe_get_hw_thread_id);

u32 cbe_cpu_to_node(int cpu)
{
        return cbe_thread_map[cpu].cbe_id;
}
EXPORT_SYMBOL_GPL(cbe_cpu_to_node);

u32 cbe_node_to_cpu(int node)
{
        return cpumask_first(&cbe_local_mask[node]);

}
EXPORT_SYMBOL_GPL(cbe_node_to_cpu);

static struct device_node *cbe_get_be_node(int cpu_id)
{
        struct device_node *np;

        for_each_node_by_type (np, "be") {
                int len,i;
                const phandle *cpu_handle;

                cpu_handle = of_get_property(np, "cpus", &len);

                /*
                 * the CAB SLOF tree is non compliant, so we just assume
                 * there is only one node
                 */
                if (WARN_ON_ONCE(!cpu_handle))
                        return np;

                for (i=0; i<len; i++)
                        if (of_find_node_by_phandle(cpu_handle[i]) == of_get_cpu_node(cpu_id, NULL))
                                return np;
        }

        return NULL;
}

static void __init cbe_fill_regs_map(struct cbe_regs_map *map)
{
        if(map->be_node) {
                struct device_node *be, *np;

                be = map->be_node;

                for_each_node_by_type(np, "pervasive")
                        if (of_get_parent(np) == be)
                                map->pmd_regs = of_iomap(np, 0);

                for_each_node_by_type(np, "CBEA-Internal-Interrupt-Controller")
                        if (of_get_parent(np) == be)
                                map->iic_regs = of_iomap(np, 2);

                for_each_node_by_type(np, "mic-tm")
                        if (of_get_parent(np) == be)
                                map->mic_tm_regs = of_iomap(np, 0);
        } else {
                struct device_node *cpu;
                /* That hack must die die die ! */
                const struct address_prop {
                        unsigned long address;
                        unsigned int len;
                } __attribute__((packed)) *prop;

                cpu = map->cpu_node;

                prop = of_get_property(cpu, "pervasive", NULL);
                if (prop != NULL)
                        map->pmd_regs = ioremap(prop->address, prop->len);

                prop = of_get_property(cpu, "iic", NULL);
                if (prop != NULL)
                        map->iic_regs = ioremap(prop->address, prop->len);

                prop = of_get_property(cpu, "mic-tm", NULL);
                if (prop != NULL)
                        map->mic_tm_regs = ioremap(prop->address, prop->len);
        }
}


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

        /* Build local fast map of CPUs */
        for_each_possible_cpu(i) {
                cbe_thread_map[i].cpu_node = of_get_cpu_node(i, &thread_id);
                cbe_thread_map[i].be_node = cbe_get_be_node(i);
                cbe_thread_map[i].thread_id = thread_id;
        }

        /* Find maps for each device tree CPU */
        for_each_node_by_type(cpu, "cpu") {
                struct cbe_regs_map *map;
                unsigned int cbe_id;

                cbe_id = cbe_regs_map_count++;
                map = &cbe_regs_maps[cbe_id];

                if (cbe_regs_map_count > MAX_CBE) {
                        printk(KERN_ERR "cbe_regs: More BE chips than supported"
                               "!\n");
                        cbe_regs_map_count--;
                        of_node_put(cpu);
                        return;
                }
                map->cpu_node = cpu;

                for_each_possible_cpu(i) {
                        struct cbe_thread_map *thread = &cbe_thread_map[i];

                        if (thread->cpu_node == cpu) {
                                thread->regs = map;
                                thread->cbe_id = cbe_id;
                                map->be_node = thread->be_node;
                                cpumask_set_cpu(i, &cbe_local_mask[cbe_id]);
                                if(thread->thread_id == 0)
                                        cpumask_set_cpu(i, &cbe_first_online_cpu);
                        }
                }

                cbe_fill_regs_map(map);
        }
}