[SPARC64]: Abstract out mdesc accesses for better MD update handling.

[mirror_ubuntu-zesty-kernel.git] / arch / sparc64 / kernel / mdesc.c

/* mdesc.c: Sun4V machine description handling.
 *
 * Copyright (C) 2007 David S. Miller <davem@davemloft.net>
 */
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/bootmem.h>
#include <linux/log2.h>
#include <linux/list.h>
#include <linux/slab.h>

#include <asm/hypervisor.h>
#include <asm/mdesc.h>
#include <asm/prom.h>
#include <asm/oplib.h>
#include <asm/smp.h>

/* Unlike the OBP device tree, the machine description is a full-on
 * DAG.  An arbitrary number of ARCs are possible from one
 * node to other nodes and thus we can't use the OBP device_node
 * data structure to represent these nodes inside of the kernel.
 *
 * Actually, it isn't even a DAG, because there are back pointers
 * which create cycles in the graph.
 *
 * mdesc_hdr and mdesc_elem describe the layout of the data structure
 * we get from the Hypervisor.
 */
struct mdesc_hdr {
        u32     version; /* Transport version */
        u32     node_sz; /* node block size */
        u32     name_sz; /* name block size */
        u32     data_sz; /* data block size */
} __attribute__((aligned(16)));

struct mdesc_elem {
        u8      tag;
#define MD_LIST_END     0x00
#define MD_NODE         0x4e
#define MD_NODE_END     0x45
#define MD_NOOP         0x20
#define MD_PROP_ARC     0x61
#define MD_PROP_VAL     0x76
#define MD_PROP_STR     0x73
#define MD_PROP_DATA    0x64
        u8      name_len;
        u16     resv;
        u32     name_offset;
        union {
                struct {
                        u32     data_len;
                        u32     data_offset;
                } data;
                u64     val;
        } d;
};

struct mdesc_mem_ops {
        struct mdesc_handle *(*alloc)(unsigned int mdesc_size);
        void (*free)(struct mdesc_handle *handle);
};

struct mdesc_handle {
        struct list_head        list;
        struct mdesc_mem_ops    *mops;
        void                    *self_base;
        atomic_t                refcnt;
        unsigned int            handle_size;
        struct mdesc_hdr        mdesc;
};

static void mdesc_handle_init(struct mdesc_handle *hp,
                              unsigned int handle_size,
                              void *base)
{
        BUG_ON(((unsigned long)&hp->mdesc) & (16UL - 1));

        memset(hp, 0, handle_size);
        INIT_LIST_HEAD(&hp->list);
        hp->self_base = base;
        atomic_set(&hp->refcnt, 1);
        hp->handle_size = handle_size;
}

static struct mdesc_handle *mdesc_bootmem_alloc(unsigned int mdesc_size)
{
        struct mdesc_handle *hp;
        unsigned int handle_size, alloc_size;

        handle_size = (sizeof(struct mdesc_handle) -
                       sizeof(struct mdesc_hdr) +
                       mdesc_size);
        alloc_size = PAGE_ALIGN(handle_size);

        hp = __alloc_bootmem(alloc_size, PAGE_SIZE, 0UL);
        if (hp)
                mdesc_handle_init(hp, handle_size, hp);

        return hp;
}

static void mdesc_bootmem_free(struct mdesc_handle *hp)
{
        unsigned int alloc_size, handle_size = hp->handle_size;
        unsigned long start, end;

        BUG_ON(atomic_read(&hp->refcnt) != 0);
        BUG_ON(!list_empty(&hp->list));

        alloc_size = PAGE_ALIGN(handle_size);

        start = (unsigned long) hp;
        end = start + alloc_size;

        while (start < end) {
                struct page *p;

                p = virt_to_page(start);
                ClearPageReserved(p);
                __free_page(p);
                start += PAGE_SIZE;
        }
}

static struct mdesc_mem_ops bootmem_mdesc_memops = {
        .alloc = mdesc_bootmem_alloc,
        .free  = mdesc_bootmem_free,
};

static struct mdesc_handle *mdesc_kmalloc(unsigned int mdesc_size)
{
        unsigned int handle_size;
        void *base;

        handle_size = (sizeof(struct mdesc_handle) -
                       sizeof(struct mdesc_hdr) +
                       mdesc_size);

        base = kmalloc(handle_size + 15, GFP_KERNEL);
        if (base) {
                struct mdesc_handle *hp;
                unsigned long addr;

                addr = (unsigned long)base;
                addr = (addr + 15UL) & ~15UL;
                hp = (struct mdesc_handle *) addr;

                mdesc_handle_init(hp, handle_size, base);
                return hp;
        }

        return NULL;
}

static void mdesc_kfree(struct mdesc_handle *hp)
{
        BUG_ON(atomic_read(&hp->refcnt) != 0);
        BUG_ON(!list_empty(&hp->list));

        kfree(hp->self_base);
}

static struct mdesc_mem_ops kmalloc_mdesc_memops = {
        .alloc = mdesc_kmalloc,
        .free  = mdesc_kfree,
};

static struct mdesc_handle *mdesc_alloc(unsigned int mdesc_size,
                                        struct mdesc_mem_ops *mops)
{
        struct mdesc_handle *hp = mops->alloc(mdesc_size);

        if (hp)
                hp->mops = mops;

        return hp;
}

static void mdesc_free(struct mdesc_handle *hp)
{
        hp->mops->free(hp);
}

static struct mdesc_handle *cur_mdesc;
static LIST_HEAD(mdesc_zombie_list);
static DEFINE_SPINLOCK(mdesc_lock);

struct mdesc_handle *mdesc_grab(void)
{
        struct mdesc_handle *hp;
        unsigned long flags;

        spin_lock_irqsave(&mdesc_lock, flags);
        hp = cur_mdesc;
        if (hp)
                atomic_inc(&hp->refcnt);
        spin_unlock_irqrestore(&mdesc_lock, flags);

        return hp;
}
EXPORT_SYMBOL(mdesc_grab);

void mdesc_release(struct mdesc_handle *hp)
{
        unsigned long flags;

        spin_lock_irqsave(&mdesc_lock, flags);
        if (atomic_dec_and_test(&hp->refcnt)) {
                list_del_init(&hp->list);
                hp->mops->free(hp);
        }
        spin_unlock_irqrestore(&mdesc_lock, flags);
}
EXPORT_SYMBOL(mdesc_release);

static void do_mdesc_update(struct work_struct *work)
{
        unsigned long len, real_len, status;
        struct mdesc_handle *hp, *orig_hp;
        unsigned long flags;

        (void) sun4v_mach_desc(0UL, 0UL, &len);

        hp = mdesc_alloc(len, &kmalloc_mdesc_memops);
        if (!hp) {
                printk(KERN_ERR "MD: mdesc alloc fails\n");
                return;
        }

        status = sun4v_mach_desc(__pa(&hp->mdesc), len, &real_len);
        if (status != HV_EOK || real_len > len) {
                printk(KERN_ERR "MD: mdesc reread fails with %lu\n",
                       status);
                atomic_dec(&hp->refcnt);
                mdesc_free(hp);
                return;
        }

        spin_lock_irqsave(&mdesc_lock, flags);
        orig_hp = cur_mdesc;
        cur_mdesc = hp;

        if (atomic_dec_and_test(&orig_hp->refcnt))
                mdesc_free(orig_hp);
        else
                list_add(&orig_hp->list, &mdesc_zombie_list);
        spin_unlock_irqrestore(&mdesc_lock, flags);
}

static DECLARE_WORK(mdesc_update_work, do_mdesc_update);

void mdesc_update(void)
{
        schedule_work(&mdesc_update_work);
}

static struct mdesc_elem *node_block(struct mdesc_hdr *mdesc)
{
        return (struct mdesc_elem *) (mdesc + 1);
}

static void *name_block(struct mdesc_hdr *mdesc)
{
        return ((void *) node_block(mdesc)) + mdesc->node_sz;
}

static void *data_block(struct mdesc_hdr *mdesc)
{
        return ((void *) name_block(mdesc)) + mdesc->name_sz;
}

u64 mdesc_node_by_name(struct mdesc_handle *hp,
                       u64 from_node, const char *name)
{
        struct mdesc_elem *ep = node_block(&hp->mdesc);
        const char *names = name_block(&hp->mdesc);
        u64 last_node = hp->mdesc.node_sz / 16;
        u64 ret;

        if (from_node == MDESC_NODE_NULL)
                from_node = 0;

        if (from_node >= last_node)
                return MDESC_NODE_NULL;

        ret = ep[from_node].d.val;
        while (ret < last_node) {
                if (ep[ret].tag != MD_NODE)
                        return MDESC_NODE_NULL;
                if (!strcmp(names + ep[ret].name_offset, name))
                        break;
                ret = ep[ret].d.val;
        }
        if (ret >= last_node)
                ret = MDESC_NODE_NULL;
        return ret;
}
EXPORT_SYMBOL(mdesc_node_by_name);

const void *mdesc_get_property(struct mdesc_handle *hp, u64 node,
                               const char *name, int *lenp)
{
        const char *names = name_block(&hp->mdesc);
        u64 last_node = hp->mdesc.node_sz / 16;
        void *data = data_block(&hp->mdesc);
        struct mdesc_elem *ep;

        if (node == MDESC_NODE_NULL || node >= last_node)
                return NULL;

        ep = node_block(&hp->mdesc) + node;
        ep++;
        for (; ep->tag != MD_NODE_END; ep++) {
                void *val = NULL;
                int len = 0;

                switch (ep->tag) {
                case MD_PROP_VAL:
                        val = &ep->d.val;
                        len = 8;
                        break;

                case MD_PROP_STR:
                case MD_PROP_DATA:
                        val = data + ep->d.data.data_offset;
                        len = ep->d.data.data_len;
                        break;

                default:
                        break;
                }
                if (!val)
                        continue;

                if (!strcmp(names + ep->name_offset, name)) {
                        if (lenp)
                                *lenp = len;
                        return val;
                }
        }

        return NULL;
}
EXPORT_SYMBOL(mdesc_get_property);

u64 mdesc_next_arc(struct mdesc_handle *hp, u64 from, const char *arc_type)
{
        struct mdesc_elem *ep, *base = node_block(&hp->mdesc);
        const char *names = name_block(&hp->mdesc);
        u64 last_node = hp->mdesc.node_sz / 16;

        if (from == MDESC_NODE_NULL || from >= last_node)
                return MDESC_NODE_NULL;

        ep = base + from;

        ep++;
        for (; ep->tag != MD_NODE_END; ep++) {
                if (ep->tag != MD_PROP_ARC)
                        continue;

                if (strcmp(names + ep->name_offset, arc_type))
                        continue;

                return ep - base;
        }

        return MDESC_NODE_NULL;
}
EXPORT_SYMBOL(mdesc_next_arc);

u64 mdesc_arc_target(struct mdesc_handle *hp, u64 arc)
{
        struct mdesc_elem *ep, *base = node_block(&hp->mdesc);

        ep = base + arc;

        return ep->d.val;
}
EXPORT_SYMBOL(mdesc_arc_target);

const char *mdesc_node_name(struct mdesc_handle *hp, u64 node)
{
        struct mdesc_elem *ep, *base = node_block(&hp->mdesc);
        const char *names = name_block(&hp->mdesc);
        u64 last_node = hp->mdesc.node_sz / 16;

        if (node == MDESC_NODE_NULL || node >= last_node)
                return NULL;

        ep = base + node;
        if (ep->tag != MD_NODE)
                return NULL;

        return names + ep->name_offset;
}
EXPORT_SYMBOL(mdesc_node_name);

static void __init report_platform_properties(void)
{
        struct mdesc_handle *hp = mdesc_grab();
        u64 pn = mdesc_node_by_name(hp, MDESC_NODE_NULL, "platform");
        const char *s;
        const u64 *v;

        if (pn == MDESC_NODE_NULL) {
                prom_printf("No platform node in machine-description.\n");
                prom_halt();
        }

        s = mdesc_get_property(hp, pn, "banner-name", NULL);
        printk("PLATFORM: banner-name [%s]\n", s);
        s = mdesc_get_property(hp, pn, "name", NULL);
        printk("PLATFORM: name [%s]\n", s);

        v = mdesc_get_property(hp, pn, "hostid", NULL);
        if (v)
                printk("PLATFORM: hostid [%08lx]\n", *v);
        v = mdesc_get_property(hp, pn, "serial#", NULL);
        if (v)
                printk("PLATFORM: serial# [%08lx]\n", *v);
        v = mdesc_get_property(hp, pn, "stick-frequency", NULL);
        printk("PLATFORM: stick-frequency [%08lx]\n", *v);
        v = mdesc_get_property(hp, pn, "mac-address", NULL);
        if (v)
                printk("PLATFORM: mac-address [%lx]\n", *v);
        v = mdesc_get_property(hp, pn, "watchdog-resolution", NULL);
        if (v)
                printk("PLATFORM: watchdog-resolution [%lu ms]\n", *v);
        v = mdesc_get_property(hp, pn, "watchdog-max-timeout", NULL);
        if (v)
                printk("PLATFORM: watchdog-max-timeout [%lu ms]\n", *v);
        v = mdesc_get_property(hp, pn, "max-cpus", NULL);
        if (v)
                printk("PLATFORM: max-cpus [%lu]\n", *v);

        mdesc_release(hp);
}

static int inline find_in_proplist(const char *list, const char *match, int len)
{
        while (len > 0) {
                int l;

                if (!strcmp(list, match))
                        return 1;
                l = strlen(list) + 1;
                list += l;
                len -= l;
        }
        return 0;
}

static void __init fill_in_one_cache(cpuinfo_sparc *c,
                                     struct mdesc_handle *hp,
                                     u64 mp)
{
        const u64 *level = mdesc_get_property(hp, mp, "level", NULL);
        const u64 *size = mdesc_get_property(hp, mp, "size", NULL);
        const u64 *line_size = mdesc_get_property(hp, mp, "line-size", NULL);
        const char *type;
        int type_len;

        type = mdesc_get_property(hp, mp, "type", &type_len);

        switch (*level) {
        case 1:
                if (find_in_proplist(type, "instn", type_len)) {
                        c->icache_size = *size;
                        c->icache_line_size = *line_size;
                } else if (find_in_proplist(type, "data", type_len)) {
                        c->dcache_size = *size;
                        c->dcache_line_size = *line_size;
                }
                break;

        case 2:
                c->ecache_size = *size;
                c->ecache_line_size = *line_size;
                break;

        default:
                break;
        }

        if (*level == 1) {
                u64 a;

                mdesc_for_each_arc(a, hp, mp, MDESC_ARC_TYPE_FWD) {
                        u64 target = mdesc_arc_target(hp, a);
                        const char *name = mdesc_node_name(hp, target);

                        if (!strcmp(name, "cache"))
                                fill_in_one_cache(c, hp, target);
                }
        }
}

static void __init mark_core_ids(struct mdesc_handle *hp, u64 mp, int core_id)
{
        u64 a;

        mdesc_for_each_arc(a, hp, mp, MDESC_ARC_TYPE_BACK) {
                u64 t = mdesc_arc_target(hp, a);
                const char *name;
                const u64 *id;

                name = mdesc_node_name(hp, t);
                if (!strcmp(name, "cpu")) {
                        id = mdesc_get_property(hp, t, "id", NULL);
                        if (*id < NR_CPUS)
                                cpu_data(*id).core_id = core_id;
                } else {
                        u64 j;

                        mdesc_for_each_arc(j, hp, t, MDESC_ARC_TYPE_BACK) {
                                u64 n = mdesc_arc_target(hp, j);
                                const char *n_name;

                                n_name = mdesc_node_name(hp, n);
                                if (strcmp(n_name, "cpu"))
                                        continue;

                                id = mdesc_get_property(hp, n, "id", NULL);
                                if (*id < NR_CPUS)
                                        cpu_data(*id).core_id = core_id;
                        }
                }
        }
}

static void __init set_core_ids(struct mdesc_handle *hp)
{
        int idx;
        u64 mp;

        idx = 1;
        mdesc_for_each_node_by_name(hp, mp, "cache") {
                const u64 *level;
                const char *type;
                int len;

                level = mdesc_get_property(hp, mp, "level", NULL);
                if (*level != 1)
                        continue;

                type = mdesc_get_property(hp, mp, "type", &len);
                if (!find_in_proplist(type, "instn", len))
                        continue;

                mark_core_ids(hp, mp, idx);

                idx++;
        }
}

static void __init mark_proc_ids(struct mdesc_handle *hp, u64 mp, int proc_id)
{
        u64 a;

        mdesc_for_each_arc(a, hp, mp, MDESC_ARC_TYPE_BACK) {
                u64 t = mdesc_arc_target(hp, a);
                const char *name;
                const u64 *id;

                name = mdesc_node_name(hp, t);
                if (strcmp(name, "cpu"))
                        continue;

                id = mdesc_get_property(hp, t, "id", NULL);
                if (*id < NR_CPUS)
                        cpu_data(*id).proc_id = proc_id;
        }
}

static void __init __set_proc_ids(struct mdesc_handle *hp,
                                  const char *exec_unit_name)
{
        int idx;
        u64 mp;

        idx = 0;
        mdesc_for_each_node_by_name(hp, mp, exec_unit_name) {
                const char *type;
                int len;

                type = mdesc_get_property(hp, mp, "type", &len);
                if (!find_in_proplist(type, "int", len) &&
                    !find_in_proplist(type, "integer", len))
                        continue;

                mark_proc_ids(hp, mp, idx);

                idx++;
        }
}

static void __init set_proc_ids(struct mdesc_handle *hp)
{
        __set_proc_ids(hp, "exec_unit");
        __set_proc_ids(hp, "exec-unit");
}

static void __init get_one_mondo_bits(const u64 *p, unsigned int *mask, unsigned char def)
{
        u64 val;

        if (!p)
                goto use_default;
        val = *p;

        if (!val || val >= 64)
                goto use_default;

        *mask = ((1U << val) * 64U) - 1U;
        return;

use_default:
        *mask = ((1U << def) * 64U) - 1U;
}

static void __init get_mondo_data(struct mdesc_handle *hp, u64 mp,
                                  struct trap_per_cpu *tb)
{
        const u64 *val;

        val = mdesc_get_property(hp, mp, "q-cpu-mondo-#bits", NULL);
        get_one_mondo_bits(val, &tb->cpu_mondo_qmask, 7);

        val = mdesc_get_property(hp, mp, "q-dev-mondo-#bits", NULL);
        get_one_mondo_bits(val, &tb->dev_mondo_qmask, 7);

        val = mdesc_get_property(hp, mp, "q-resumable-#bits", NULL);
        get_one_mondo_bits(val, &tb->resum_qmask, 6);

        val = mdesc_get_property(hp, mp, "q-nonresumable-#bits", NULL);
        get_one_mondo_bits(val, &tb->nonresum_qmask, 2);
}

static void __init mdesc_fill_in_cpu_data(void)
{
        struct mdesc_handle *hp = mdesc_grab();
        u64 mp;

        ncpus_probed = 0;
        mdesc_for_each_node_by_name(hp, mp, "cpu") {
                const u64 *id = mdesc_get_property(hp, mp, "id", NULL);
                const u64 *cfreq = mdesc_get_property(hp, mp, "clock-frequency", NULL);
                struct trap_per_cpu *tb;
                cpuinfo_sparc *c;
                int cpuid;
                u64 a;

                ncpus_probed++;

                cpuid = *id;

#ifdef CONFIG_SMP
                if (cpuid >= NR_CPUS)
                        continue;
#else
                /* On uniprocessor we only want the values for the
                 * real physical cpu the kernel booted onto, however
                 * cpu_data() only has one entry at index 0.
                 */
                if (cpuid != real_hard_smp_processor_id())
                        continue;
                cpuid = 0;
#endif

                c = &cpu_data(cpuid);
                c->clock_tick = *cfreq;

                tb = &trap_block[cpuid];
                get_mondo_data(hp, mp, tb);

                mdesc_for_each_arc(a, hp, mp, MDESC_ARC_TYPE_FWD) {
                        u64 j, t = mdesc_arc_target(hp, a);
                        const char *t_name;

                        t_name = mdesc_node_name(hp, t);
                        if (!strcmp(t_name, "cache")) {
                                fill_in_one_cache(c, hp, t);
                                continue;
                        }

                        mdesc_for_each_arc(j, hp, t, MDESC_ARC_TYPE_FWD) {
                                u64 n = mdesc_arc_target(hp, j);
                                const char *n_name;

                                n_name = mdesc_node_name(hp, n);
                                if (!strcmp(n_name, "cache"))
                                        fill_in_one_cache(c, hp, n);
                        }
                }

#ifdef CONFIG_SMP
                cpu_set(cpuid, cpu_present_map);
                cpu_set(cpuid, phys_cpu_present_map);
#endif

                c->core_id = 0;
                c->proc_id = -1;
        }

#ifdef CONFIG_SMP
        sparc64_multi_core = 1;
#endif

        set_core_ids(hp);
        set_proc_ids(hp);

        smp_fill_in_sib_core_maps();

        mdesc_release(hp);
}

void __init sun4v_mdesc_init(void)
{
        struct mdesc_handle *hp;
        unsigned long len, real_len, status;

        (void) sun4v_mach_desc(0UL, 0UL, &len);

        printk("MDESC: Size is %lu bytes.\n", len);

        hp = mdesc_alloc(len, &bootmem_mdesc_memops);
        if (hp == NULL) {
                prom_printf("MDESC: alloc of %lu bytes failed.\n", len);
                prom_halt();
        }

        status = sun4v_mach_desc(__pa(&hp->mdesc), len, &real_len);
        if (status != HV_EOK || real_len > len) {
                prom_printf("sun4v_mach_desc fails, err(%lu), "
                            "len(%lu), real_len(%lu)\n",
                            status, len, real_len);
                mdesc_free(hp);
                prom_halt();
        }

        cur_mdesc = hp;

        report_platform_properties();
        mdesc_fill_in_cpu_data();
}