address.c

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#include <linux/device.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/pci_regs.h>
#include <linux/string.h>

/* Max address size we deal with */
#define OF_MAX_ADDR_CELLS   4
#define OF_CHECK_ADDR_COUNT(na) ((na) > 0 && (na) <= OF_MAX_ADDR_CELLS)
#define OF_CHECK_COUNTS(na, ns) (OF_CHECK_ADDR_COUNT(na) && (ns) > 0)

static struct of_bus *of_match_bus(struct device_node *np);
static int __of_address_to_resource(struct device_node *dev,
        const __be32 *addrp, u64 size, unsigned int flags,
        const char *name, struct resource *r);

/* Debug utility */
#ifdef DEBUG
static void of_dump_addr(const char *s, const __be32 *addr, int na)
{
    printk(KERN_DEBUG "%s", s);
    while (na--)
        printk(" %08x", be32_to_cpu(*(addr++)));
    printk("\n");
}
#else
static void of_dump_addr(const char *s, const __be32 *addr, int na) { }
#endif

/* Callbacks for bus specific translators */
struct of_bus {
    const char  *name;
    const char  *addresses;
    int     (*match)(struct device_node *parent);
    void        (*count_cells)(struct device_node *child,
                       int *addrc, int *sizec);
    u64     (*map)(__be32 *addr, const __be32 *range,
                int na, int ns, int pna);
    int     (*translate)(__be32 *addr, u64 offset, int na);
    unsigned int    (*get_flags)(const __be32 *addr);
};

/*
 * Default translator (generic bus)
 */

static void of_bus_default_count_cells(struct device_node *dev,
                       int *addrc, int *sizec)
{
    if (addrc)
        *addrc = of_n_addr_cells(dev);
    if (sizec)
        *sizec = of_n_size_cells(dev);
}

static u64 of_bus_default_map(__be32 *addr, const __be32 *range,
        int na, int ns, int pna)
{
    u64 cp, s, da;

    cp = of_read_number(range, na);
    s  = of_read_number(range + na + pna, ns);
    da = of_read_number(addr, na);

    pr_debug("OF: default map, cp=%llx, s=%llx, da=%llx\n",
         (unsigned long long)cp, (unsigned long long)s,
         (unsigned long long)da);

    /*
     * If the number of address cells is larger than 2 we assume the
     * mapping doesn't specify a physical address. Rather, the address
     * specifies an identifier that must match exactly.
     */
    if (na > 2 && memcmp(range, addr, na * 4) != 0)
        return OF_BAD_ADDR;

    if (da < cp || da >= (cp + s))
        return OF_BAD_ADDR;
    return da - cp;
}

static int of_bus_default_translate(__be32 *addr, u64 offset, int na)
{
    u64 a = of_read_number(addr, na);
    memset(addr, 0, na * 4);
    a += offset;
    if (na > 1)
        addr[na - 2] = cpu_to_be32(a >> 32);
    addr[na - 1] = cpu_to_be32(a & 0xffffffffu);

    return 0;
}

static unsigned int of_bus_default_get_flags(const __be32 *addr)
{
    return IORESOURCE_MEM;
}

#ifdef CONFIG_PCI
/*
 * PCI bus specific translator
 */

static int of_bus_pci_match(struct device_node *np)
{
    /* "vci" is for the /chaos bridge on 1st-gen PCI powermacs */
    return !strcmp(np->type, "pci") || !strcmp(np->type, "vci");
}

static void of_bus_pci_count_cells(struct device_node *np,
                   int *addrc, int *sizec)
{
    if (addrc)
        *addrc = 3;
    if (sizec)
        *sizec = 2;
}

static unsigned int of_bus_pci_get_flags(const __be32 *addr)
{
    unsigned int flags = 0;
    u32 w = be32_to_cpup(addr);

    switch((w >> 24) & 0x03) {
    case 0x01:
        flags |= IORESOURCE_IO;
        break;
    case 0x02: /* 32 bits */
    case 0x03: /* 64 bits */
        flags |= IORESOURCE_MEM;
        break;
    }
    if (w & 0x40000000)
        flags |= IORESOURCE_PREFETCH;
    return flags;
}

static u64 of_bus_pci_map(__be32 *addr, const __be32 *range, int na, int ns,
        int pna)
{
    u64 cp, s, da;
    unsigned int af, rf;

    af = of_bus_pci_get_flags(addr);
    rf = of_bus_pci_get_flags(range);

    /* Check address type match */
    if ((af ^ rf) & (IORESOURCE_MEM | IORESOURCE_IO))
        return OF_BAD_ADDR;

    /* Read address values, skipping high cell */
    cp = of_read_number(range + 1, na - 1);
    s  = of_read_number(range + na + pna, ns);
    da = of_read_number(addr + 1, na - 1);

    pr_debug("OF: PCI map, cp=%llx, s=%llx, da=%llx\n",
         (unsigned long long)cp, (unsigned long long)s,
         (unsigned long long)da);

    if (da < cp || da >= (cp + s))
        return OF_BAD_ADDR;
    return da - cp;
}

static int of_bus_pci_translate(__be32 *addr, u64 offset, int na)
{
    return of_bus_default_translate(addr + 1, offset, na - 1);
}

const __be32 *of_get_pci_address(struct device_node *dev, int bar_no, u64 *size,
            unsigned int *flags)
{
    const __be32 *prop;
    unsigned int psize;
    struct device_node *parent;
    struct of_bus *bus;
    int onesize, i, na, ns;

    /* Get parent & match bus type */
    parent = of_get_parent(dev);
    if (parent == NULL)
        return NULL;
    bus = of_match_bus(parent);
    if (strcmp(bus->name, "pci")) {
        of_node_put(parent);
        return NULL;
    }
    bus->count_cells(dev, &na, &ns);
    of_node_put(parent);
    if (!OF_CHECK_ADDR_COUNT(na))
        return NULL;

    /* Get "reg" or "assigned-addresses" property */
    prop = of_get_property(dev, bus->addresses, &psize);
    if (prop == NULL)
        return NULL;
    psize /= 4;

    onesize = na + ns;
    for (i = 0; psize >= onesize; psize -= onesize, prop += onesize, i++) {
        u32 val = be32_to_cpu(prop[0]);
        if ((val & 0xff) == ((bar_no * 4) + PCI_BASE_ADDRESS_0)) {
            if (size)
                *size = of_read_number(prop + na, ns);
            if (flags)
                *flags = bus->get_flags(prop);
            return prop;
        }
    }
    return NULL;
}
EXPORT_SYMBOL(of_get_pci_address);

int of_pci_address_to_resource(struct device_node *dev, int bar,
                   struct resource *r)
{
    const __be32    *addrp;
    u64     size;
    unsigned int    flags;

    addrp = of_get_pci_address(dev, bar, &size, &flags);
    if (addrp == NULL)
        return -EINVAL;
    return __of_address_to_resource(dev, addrp, size, flags, NULL, r);
}
EXPORT_SYMBOL_GPL(of_pci_address_to_resource);
#endif /* CONFIG_PCI */

/*
 * ISA bus specific translator
 */

static int of_bus_isa_match(struct device_node *np)
{
    return !strcmp(np->name, "isa");
}

static void of_bus_isa_count_cells(struct device_node *child,
                   int *addrc, int *sizec)
{
    if (addrc)
        *addrc = 2;
    if (sizec)
        *sizec = 1;
}

static u64 of_bus_isa_map(__be32 *addr, const __be32 *range, int na, int ns,
        int pna)
{
    u64 cp, s, da;

    /* Check address type match */
    if ((addr[0] ^ range[0]) & cpu_to_be32(1))
        return OF_BAD_ADDR;

    /* Read address values, skipping high cell */
    cp = of_read_number(range + 1, na - 1);
    s  = of_read_number(range + na + pna, ns);
    da = of_read_number(addr + 1, na - 1);

    pr_debug("OF: ISA map, cp=%llx, s=%llx, da=%llx\n",
         (unsigned long long)cp, (unsigned long long)s,
         (unsigned long long)da);

    if (da < cp || da >= (cp + s))
        return OF_BAD_ADDR;
    return da - cp;
}

static int of_bus_isa_translate(__be32 *addr, u64 offset, int na)
{
    return of_bus_default_translate(addr + 1, offset, na - 1);
}

static unsigned int of_bus_isa_get_flags(const __be32 *addr)
{
    unsigned int flags = 0;
    u32 w = be32_to_cpup(addr);

    if (w & 1)
        flags |= IORESOURCE_IO;
    else
        flags |= IORESOURCE_MEM;
    return flags;
}

/*
 * Array of bus specific translators
 */

static struct of_bus of_busses[] = {
#ifdef CONFIG_PCI
    /* PCI */
    {
        .name = "pci",
        .addresses = "assigned-addresses",
        .match = of_bus_pci_match,
        .count_cells = of_bus_pci_count_cells,
        .map = of_bus_pci_map,
        .translate = of_bus_pci_translate,
        .get_flags = of_bus_pci_get_flags,
    },
#endif /* CONFIG_PCI */
    /* ISA */
    {
        .name = "isa",
        .addresses = "reg",
        .match = of_bus_isa_match,
        .count_cells = of_bus_isa_count_cells,
        .map = of_bus_isa_map,
        .translate = of_bus_isa_translate,
        .get_flags = of_bus_isa_get_flags,
    },
    /* Default */
    {
        .name = "default",
        .addresses = "reg",
        .match = NULL,
        .count_cells = of_bus_default_count_cells,
        .map = of_bus_default_map,
        .translate = of_bus_default_translate,
        .get_flags = of_bus_default_get_flags,
    },
};

static struct of_bus *of_match_bus(struct device_node *np)
{
    int i;

    for (i = 0; i < ARRAY_SIZE(of_busses); i++)
        if (!of_busses[i].match || of_busses[i].match(np))
            return &of_busses[i];
    BUG();
    return NULL;
}

static int of_translate_one(struct device_node *parent, struct of_bus *bus,
                struct of_bus *pbus, __be32 *addr,
                int na, int ns, int pna, const char *rprop)
{
    const __be32 *ranges;
    unsigned int rlen;
    int rone;
    u64 offset = OF_BAD_ADDR;

    /* Normally, an absence of a "ranges" property means we are
     * crossing a non-translatable boundary, and thus the addresses
     * below the current not cannot be converted to CPU physical ones.
     * Unfortunately, while this is very clear in the spec, it's not
     * what Apple understood, and they do have things like /uni-n or
     * /ht nodes with no "ranges" property and a lot of perfectly
     * useable mapped devices below them. Thus we treat the absence of
     * "ranges" as equivalent to an empty "ranges" property which means
     * a 1:1 translation at that level. It's up to the caller not to try
     * to translate addresses that aren't supposed to be translated in
     * the first place. --BenH.
     *
     * As far as we know, this damage only exists on Apple machines, so
     * This code is only enabled on powerpc. --gcl
     */
    ranges = of_get_property(parent, rprop, &rlen);
#if !defined(CONFIG_PPC)
    if (ranges == NULL) {
        pr_err("OF: no ranges; cannot translate\n");
        return 1;
    }
#endif /* !defined(CONFIG_PPC) */
    if (ranges == NULL || rlen == 0) {
        offset = of_read_number(addr, na);
        memset(addr, 0, pna * 4);
        pr_debug("OF: empty ranges; 1:1 translation\n");
        goto finish;
    }

    pr_debug("OF: walking ranges...\n");

    /* Now walk through the ranges */
    rlen /= 4;
    rone = na + pna + ns;
    for (; rlen >= rone; rlen -= rone, ranges += rone) {
        offset = bus->map(addr, ranges, na, ns, pna);
        if (offset != OF_BAD_ADDR)
            break;
    }
    if (offset == OF_BAD_ADDR) {
        pr_debug("OF: not found !\n");
        return 1;
    }
    memcpy(addr, ranges + na, 4 * pna);

 finish:
    of_dump_addr("OF: parent translation for:", addr, pna);
    pr_debug("OF: with offset: %llx\n", (unsigned long long)offset);

    /* Translate it into parent bus space */
    return pbus->translate(addr, offset, pna);
}

/*
 * Translate an address from the device-tree into a CPU physical address,
 * this walks up the tree and applies the various bus mappings on the
 * way.
 *
 * Note: We consider that crossing any level with #size-cells == 0 to mean
 * that translation is impossible (that is we are not dealing with a value
 * that can be mapped to a cpu physical address). This is not really specified
 * that way, but this is traditionally the way IBM at least do things
 */
static u64 __of_translate_address(struct device_node *dev,
                  const __be32 *in_addr, const char *rprop)
{
    struct device_node *parent = NULL;
    struct of_bus *bus, *pbus;
    __be32 addr[OF_MAX_ADDR_CELLS];
    int na, ns, pna, pns;
    u64 result = OF_BAD_ADDR;

    pr_debug("OF: ** translation for device %s **\n", dev->full_name);

    /* Increase refcount at current level */
    of_node_get(dev);

    /* Get parent & match bus type */
    parent = of_get_parent(dev);
    if (parent == NULL)
        goto bail;
    bus = of_match_bus(parent);

    /* Cound address cells & copy address locally */
    bus->count_cells(dev, &na, &ns);
    if (!OF_CHECK_COUNTS(na, ns)) {
        printk(KERN_ERR "prom_parse: Bad cell count for %s\n",
               dev->full_name);
        goto bail;
    }
    memcpy(addr, in_addr, na * 4);

    pr_debug("OF: bus is %s (na=%d, ns=%d) on %s\n",
        bus->name, na, ns, parent->full_name);
    of_dump_addr("OF: translating address:", addr, na);

    /* Translate */
    for (;;) {
        /* Switch to parent bus */
        of_node_put(dev);
        dev = parent;
        parent = of_get_parent(dev);

        /* If root, we have finished */
        if (parent == NULL) {
            pr_debug("OF: reached root node\n");
            result = of_read_number(addr, na);
            break;
        }

        /* Get new parent bus and counts */
        pbus = of_match_bus(parent);
        pbus->count_cells(dev, &pna, &pns);
        if (!OF_CHECK_COUNTS(pna, pns)) {
            printk(KERN_ERR "prom_parse: Bad cell count for %s\n",
                   dev->full_name);
            break;
        }

        pr_debug("OF: parent bus is %s (na=%d, ns=%d) on %s\n",
            pbus->name, pna, pns, parent->full_name);

        /* Apply bus translation */
        if (of_translate_one(dev, bus, pbus, addr, na, ns, pna, rprop))
            break;

        /* Complete the move up one level */
        na = pna;
        ns = pns;
        bus = pbus;

        of_dump_addr("OF: one level translation:", addr, na);
    }
 bail:
    of_node_put(parent);
    of_node_put(dev);

    return result;
}

u64 of_translate_address(struct device_node *dev, const __be32 *in_addr)
{
    return __of_translate_address(dev, in_addr, "ranges");
}
EXPORT_SYMBOL(of_translate_address);

u64 of_translate_dma_address(struct device_node *dev, const __be32 *in_addr)
{
    return __of_translate_address(dev, in_addr, "dma-ranges");
}
EXPORT_SYMBOL(of_translate_dma_address);

bool of_can_translate_address(struct device_node *dev)
{
    struct device_node *parent;
    struct of_bus *bus;
    int na, ns;

    parent = of_get_parent(dev);
    if (parent == NULL)
        return false;

    bus = of_match_bus(parent);
    bus->count_cells(dev, &na, &ns);

    of_node_put(parent);

    return OF_CHECK_COUNTS(na, ns);
}
EXPORT_SYMBOL(of_can_translate_address);

const __be32 *of_get_address(struct device_node *dev, int index, u64 *size,
            unsigned int *flags)
{
    const __be32 *prop;
    unsigned int psize;
    struct device_node *parent;
    struct of_bus *bus;
    int onesize, i, na, ns;

    /* Get parent & match bus type */
    parent = of_get_parent(dev);
    if (parent == NULL)
        return NULL;
    bus = of_match_bus(parent);
    bus->count_cells(dev, &na, &ns);
    of_node_put(parent);
    if (!OF_CHECK_ADDR_COUNT(na))
        return NULL;

    /* Get "reg" or "assigned-addresses" property */
    prop = of_get_property(dev, bus->addresses, &psize);
    if (prop == NULL)
        return NULL;
    psize /= 4;

    onesize = na + ns;
    for (i = 0; psize >= onesize; psize -= onesize, prop += onesize, i++)
        if (i == index) {
            if (size)
                *size = of_read_number(prop + na, ns);
            if (flags)
                *flags = bus->get_flags(prop);
            return prop;
        }
    return NULL;
}
EXPORT_SYMBOL(of_get_address);

static int __of_address_to_resource(struct device_node *dev,
        const __be32 *addrp, u64 size, unsigned int flags,
        const char *name, struct resource *r)
{
    u64 taddr;

    if ((flags & (IORESOURCE_IO | IORESOURCE_MEM)) == 0)
        return -EINVAL;
    taddr = of_translate_address(dev, addrp);
    if (taddr == OF_BAD_ADDR)
        return -EINVAL;
    memset(r, 0, sizeof(struct resource));
    if (flags & IORESOURCE_IO) {
        unsigned long port;
        port = pci_address_to_pio(taddr);
        if (port == (unsigned long)-1)
            return -EINVAL;
        r->start = port;
        r->end = port + size - 1;
    } else {
        r->start = taddr;
        r->end = taddr + size - 1;
    }
    r->flags = flags;
    r->name = name ? name : dev->full_name;

    return 0;
}

int of_address_to_resource(struct device_node *dev, int index,
               struct resource *r)
{
    const __be32    *addrp;
    u64     size;
    unsigned int    flags;
    const char  *name = NULL;

    addrp = of_get_address(dev, index, &size, &flags);
    if (addrp == NULL)
        return -EINVAL;

    /* Get optional "reg-names" property to add a name to a resource */
    of_property_read_string_index(dev, "reg-names", index, &name);

    return __of_address_to_resource(dev, addrp, size, flags, name, r);
}
EXPORT_SYMBOL_GPL(of_address_to_resource);

struct device_node *of_find_matching_node_by_address(struct device_node *from,
                    const struct of_device_id *matches,
                    u64 base_address)
{
    struct device_node *dn = of_find_matching_node(from, matches);
    struct resource res;

    while (dn) {
        if (of_address_to_resource(dn, 0, &res))
            continue;
        if (res.start == base_address)
            return dn;
        dn = of_find_matching_node(dn, matches);
    }

    return NULL;
}


void __iomem *of_iomap(struct device_node *np, int index)
{
    struct resource res;

    if (of_address_to_resource(np, index, &res))
        return NULL;

    return ioremap(res.start, resource_size(&res));
}
EXPORT_SYMBOL(of_iomap);