[POWERPC] New device-tree interrupt parsing code

Adds new routines to prom_parse to walk the device-tree for interrupt
information. This includes both direct mapping of interrupts and low
level parsing functions for use with partial trees.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 419 insertions, 24 deletions

diff --git a/arch/powerpc/kernel/prom_parse.c b/arch/powerpc/kernel/prom_parse.c
index 45df420383cc..21009b1f7869 100644
--- a/arch/powerpc/kernel/prom_parse.c
+++ b/arch/powerpc/kernel/prom_parse.c
@@ -38,14 +38,6 @@ static void of_dump_addr(const char *s, u32 *addr, int na)
 static void of_dump_addr(const char *s, u32 *addr, int na) { }
 #endif
 
-/* Read a big address */
-static inline u64 of_read_addr(u32 *cell, int size)
-{
-        u64 r = 0;
-        while (size--)
-                r = (r << 32) | *(cell++);
-        return r;
-}
 
 /* Callbacks for bus specific translators */
 struct of_bus {
@@ -77,9 +69,9 @@ static u64 of_bus_default_map(u32 *addr, u32 *range, int na, int ns, int pna)
 {
         u64 cp, s, da;
 
-        cp = of_read_addr(range, na);
-        s  = of_read_addr(range + na + pna, ns);
-        da = of_read_addr(addr, na);
+        cp = of_read_number(range, na);
+        s  = of_read_number(range + na + pna, ns);
+        da = of_read_number(addr, na);
 
         DBG("OF: default map, cp="PRu64", s="PRu64", da="PRu64"\n",
             cp, s, da);
@@ -91,7 +83,7 @@ static u64 of_bus_default_map(u32 *addr, u32 *range, int na, int ns, int pna)
 
 static int of_bus_default_translate(u32 *addr, u64 offset, int na)
 {
-        u64 a = of_read_addr(addr, na);
+        u64 a = of_read_number(addr, na);
         memset(addr, 0, na * 4);
         a += offset;
         if (na > 1)
@@ -135,9 +127,9 @@ static u64 of_bus_pci_map(u32 *addr, u32 *range, int na, int ns, int pna)
                 return OF_BAD_ADDR;
 
         /* Read address values, skipping high cell */
-        cp = of_read_addr(range + 1, na - 1);
-        s  = of_read_addr(range + na + pna, ns);
-        da = of_read_addr(addr + 1, na - 1);
+        cp = of_read_number(range + 1, na - 1);
+        s  = of_read_number(range + na + pna, ns);
+        da = of_read_number(addr + 1, na - 1);
 
         DBG("OF: PCI map, cp="PRu64", s="PRu64", da="PRu64"\n", cp, s, da);
 
@@ -195,9 +187,9 @@ static u64 of_bus_isa_map(u32 *addr, u32 *range, int na, int ns, int pna)
                 return OF_BAD_ADDR;
 
         /* Read address values, skipping high cell */
-        cp = of_read_addr(range + 1, na - 1);
-        s  = of_read_addr(range + na + pna, ns);
-        da = of_read_addr(addr + 1, na - 1);
+        cp = of_read_number(range + 1, na - 1);
+        s  = of_read_number(range + na + pna, ns);
+        da = of_read_number(addr + 1, na - 1);
 
         DBG("OF: ISA map, cp="PRu64", s="PRu64", da="PRu64"\n", cp, s, da);
 
@@ -295,7 +287,7 @@ static int of_translate_one(struct device_node *parent, struct of_bus *bus,
          */
         ranges = (u32 *)get_property(parent, "ranges", &rlen);
         if (ranges == NULL || rlen == 0) {
-                offset = of_read_addr(addr, na);
+                offset = of_read_number(addr, na);
                 memset(addr, 0, pna * 4);
                 DBG("OF: no ranges, 1:1 translation\n");
                 goto finish;
@@ -378,7 +370,7 @@ u64 of_translate_address(struct device_node *dev, u32 *in_addr)
                 /* If root, we have finished */
                 if (parent == NULL) {
                         DBG("OF: reached root node\n");
-                        result = of_read_addr(addr, na);
+                        result = of_read_number(addr, na);
                         break;
                 }
 
@@ -442,7 +434,7 @@ u32 *of_get_address(struct device_node *dev, int index, u64 *size,
         for (i = 0; psize >= onesize; psize -= onesize, prop += onesize, i++)
                 if (i == index) {
                         if (size)
-                                *size = of_read_addr(prop + na, ns);
+                                *size = of_read_number(prop + na, ns);
                         if (flags)
                                 *flags = bus->get_flags(prop);
                         return prop;
@@ -484,7 +476,7 @@ u32 *of_get_pci_address(struct device_node *dev, int bar_no, u64 *size,
         for (i = 0; psize >= onesize; psize -= onesize, prop += onesize, i++)
                 if ((prop[0] & 0xff) == ((bar_no * 4) + PCI_BASE_ADDRESS_0)) {
                         if (size)
-                                *size = of_read_addr(prop + na, ns);
+                                *size = of_read_number(prop + na, ns);
                         if (flags)
                                 *flags = bus->get_flags(prop);
                         return prop;
@@ -565,11 +557,414 @@ void of_parse_dma_window(struct device_node *dn, unsigned char *dma_window_prop,
                 prop = get_property(dn, "#address-cells", NULL);
 
         cells = prop ? *(u32 *)prop : prom_n_addr_cells(dn);
-        *phys = of_read_addr(dma_window, cells);
+        *phys = of_read_number(dma_window, cells);
 
         dma_window += cells;
 
         prop = get_property(dn, "ibm,#dma-size-cells", NULL);
         cells = prop ? *(u32 *)prop : prom_n_size_cells(dn);
-        *size = of_read_addr(dma_window, cells);
+        *size = of_read_number(dma_window, cells);
+}
+
+/*
+ * Interrupt remapper
+ */
+
+static unsigned int of_irq_workarounds;
+static struct device_node *of_irq_dflt_pic;
+
+static struct device_node *of_irq_find_parent(struct device_node *child)
+{
+        struct device_node *p;
+        phandle *parp;
+
+        if (!of_node_get(child))
+                return NULL;
+
+        do {
+                parp = (phandle *)get_property(child, "interrupt-parent", NULL);
+                if (parp == NULL)
+                        p = of_get_parent(child);
+                else {
+                        if (of_irq_workarounds & OF_IMAP_NO_PHANDLE)
+                                p = of_node_get(of_irq_dflt_pic);
+                        else
+                                p = of_find_node_by_phandle(*parp);
+                }
+                of_node_put(child);
+                child = p;
+        } while (p && get_property(p, "#interrupt-cells", NULL) == NULL);
+
+        return p;
+}
+
+static u8 of_irq_pci_swizzle(u8 slot, u8 pin)
+{
+        return (((pin - 1) + slot) % 4) + 1;
 }
+
+/* This doesn't need to be called if you don't have any special workaround
+ * flags to pass
+ */
+void of_irq_map_init(unsigned int flags)
+{
+        of_irq_workarounds = flags;
+
+        /* OldWorld, don't bother looking at other things */
+        if (flags & OF_IMAP_OLDWORLD_MAC)
+                return;
+
+        /* If we don't have phandles, let's try to locate a default interrupt
+         * controller (happens when booting with BootX). We do a first match
+         * here, hopefully, that only ever happens on machines with one
+         * controller.
+         */
+        if (flags & OF_IMAP_NO_PHANDLE) {
+                struct device_node *np;
+
+                for(np = NULL; (np = of_find_all_nodes(np)) != NULL;) {
+                        if (get_property(np, "interrupt-controller", NULL)
+                            == NULL)
+                                continue;
+                        /* Skip /chosen/interrupt-controller */
+                        if (strcmp(np->name, "chosen") == 0)
+                                continue;
+                        /* It seems like at least one person on this planet wants
+                         * to use BootX on a machine with an AppleKiwi controller
+                         * which happens to pretend to be an interrupt
+                         * controller too.
+                         */
+                        if (strcmp(np->name, "AppleKiwi") == 0)
+                                continue;
+                        /* I think we found one ! */
+                        of_irq_dflt_pic = np;
+                        break;
+                }
+        }
+
+}
+
+int of_irq_map_raw(struct device_node *parent, u32 *intspec, u32 *addr,
+                   struct of_irq *out_irq)
+{
+        struct device_node *ipar, *tnode, *old = NULL, *newpar = NULL;
+        u32 *tmp, *imap, *imask;
+        u32 intsize = 1, addrsize, newintsize = 0, newaddrsize = 0;
+        int imaplen, match, i;
+
+        ipar = of_node_get(parent);
+
+        /* First get the #interrupt-cells property of the current cursor
+         * that tells us how to interpret the passed-in intspec. If there
+         * is none, we are nice and just walk up the tree
+         */
+        do {
+                tmp = (u32 *)get_property(ipar, "#interrupt-cells", NULL);
+                if (tmp != NULL) {
+                        intsize = *tmp;
+                        break;
+                }
+                tnode = ipar;
+                ipar = of_irq_find_parent(ipar);
+                of_node_put(tnode);
+        } while (ipar);
+        if (ipar == NULL) {
+                DBG(" -> no parent found !\n");
+                goto fail;
+        }
+
+        DBG("of_irq_map_raw: ipar=%s, size=%d\n", ipar->full_name, intsize);
+
+        /* Look for this #address-cells. We have to implement the old linux
+         * trick of looking for the parent here as some device-trees rely on it
+         */
+        old = of_node_get(ipar);
+        do {
+                tmp = (u32 *)get_property(old, "#address-cells", NULL);
+                tnode = of_get_parent(old);
+                of_node_put(old);
+                old = tnode;
+        } while(old && tmp == NULL);
+        of_node_put(old);
+        old = NULL;
+        addrsize = (tmp == NULL) ? 2 : *tmp;
+
+        DBG(" -> addrsize=%d\n", addrsize);
+
+        /* Now start the actual "proper" walk of the interrupt tree */
+        while (ipar != NULL) {
+                /* Now check if cursor is an interrupt-controller and if it is
+                 * then we are done
+                 */
+                if (get_property(ipar, "interrupt-controller", NULL) != NULL) {
+                        DBG(" -> got it !\n");
+                        memcpy(out_irq->specifier, intspec,
+                               intsize * sizeof(u32));
+                        out_irq->size = intsize;
+                        out_irq->controller = ipar;
+                        of_node_put(old);
+                        return 0;
+                }
+
+                /* Now look for an interrupt-map */
+                imap = (u32 *)get_property(ipar, "interrupt-map", &imaplen);
+                /* No interrupt map, check for an interrupt parent */
+                if (imap == NULL) {
+                        DBG(" -> no map, getting parent\n");
+                        newpar = of_irq_find_parent(ipar);
+                        goto skiplevel;
+                }
+                imaplen /= sizeof(u32);
+
+                /* Look for a mask */
+                imask = (u32 *)get_property(ipar, "interrupt-map-mask", NULL);
+
+                /* If we were passed no "reg" property and we attempt to parse
+                 * an interrupt-map, then #address-cells must be 0.
+                 * Fail if it's not.
+                 */
+                if (addr == NULL && addrsize != 0) {
+                        DBG(" -> no reg passed in when needed !\n");
+                        goto fail;
+                }
+
+                /* Parse interrupt-map */
+                match = 0;
+                while (imaplen > (addrsize + intsize + 1) && !match) {
+                        /* Compare specifiers */
+                        match = 1;
+                        for (i = 0; i < addrsize && match; ++i) {
+                                u32 mask = imask ? imask[i] : 0xffffffffu;
+                                match = ((addr[i] ^ imap[i]) & mask) == 0;
+                        }
+                        for (; i < (addrsize + intsize) && match; ++i) {
+                                u32 mask = imask ? imask[i] : 0xffffffffu;
+                                match =
+                                   ((intspec[i-addrsize] ^ imap[i]) & mask) == 0;
+                        }
+                        imap += addrsize + intsize;
+                        imaplen -= addrsize + intsize;
+
+                        DBG(" -> match=%d (imaplen=%d)\n", match, imaplen);
+
+                        /* Get the interrupt parent */
+                        if (of_irq_workarounds & OF_IMAP_NO_PHANDLE)
+                                newpar = of_node_get(of_irq_dflt_pic);
+                        else
+                                newpar = of_find_node_by_phandle((phandle)*imap);
+                        imap++;
+                        --imaplen;
+
+                        /* Check if not found */
+                        if (newpar == NULL) {
+                                DBG(" -> imap parent not found !\n");
+                                goto fail;
+                        }
+
+                        /* Get #interrupt-cells and #address-cells of new
+                         * parent
+                         */
+                        tmp = (u32 *)get_property(newpar, "#interrupt-cells",
+                                                  NULL);
+                        if (tmp == NULL) {
+                                DBG(" -> parent lacks #interrupt-cells !\n");
+                                goto fail;
+                        }
+                        newintsize = *tmp;
+                        tmp = (u32 *)get_property(newpar, "#address-cells",
+                                                  NULL);
+                        newaddrsize = (tmp == NULL) ? 0 : *tmp;
+
+                        DBG(" -> newintsize=%d, newaddrsize=%d\n",
+                            newintsize, newaddrsize);
+
+                        /* Check for malformed properties */
+                        if (imaplen < (newaddrsize + newintsize))
+                                goto fail;
+
+                        imap += newaddrsize + newintsize;
+                        imaplen -= newaddrsize + newintsize;
+
+                        DBG(" -> imaplen=%d\n", imaplen);
+                }
+                if (!match)
+                        goto fail;
+
+                of_node_put(old);
+                old = of_node_get(newpar);
+                addrsize = newaddrsize;
+                intsize = newintsize;
+                intspec = imap - intsize;
+                addr = intspec - addrsize;
+
+        skiplevel:
+                /* Iterate again with new parent */
+                DBG(" -> new parent: %s\n", newpar ? newpar->full_name : "<>");
+                of_node_put(ipar);
+                ipar = newpar;
+                newpar = NULL;
+        }
+ fail:
+        of_node_put(ipar);
+        of_node_put(old);
+        of_node_put(newpar);
+
+        return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(of_irq_map_raw);
+
+#if defined(CONFIG_PPC_PMAC) && defined(CONFIG_PPC32)
+static int of_irq_map_oldworld(struct device_node *device, int index,
+                               struct of_irq *out_irq)
+{
+        u32 *ints;
+        int intlen;
+
+        /*
+         * Old machines just have a list of interrupt numbers
+         * and no interrupt-controller nodes.
+         */
+        ints = (u32 *) get_property(device, "AAPL,interrupts", &intlen);
+        if (ints == NULL)
+                return -EINVAL;
+        intlen /= sizeof(u32);
+
+        if (index >= intlen)
+                return -EINVAL;
+
+        out_irq->controller = NULL;
+        out_irq->specifier[0] = ints[index];
+        out_irq->size = 1;
+
+        return 0;
+}
+#else /* defined(CONFIG_PPC_PMAC) && defined(CONFIG_PPC32) */
+static int of_irq_map_oldworld(struct device_node *device, int index,
+                               struct of_irq *out_irq)
+{
+        return -EINVAL;
+}
+#endif /* !(defined(CONFIG_PPC_PMAC) && defined(CONFIG_PPC32)) */
+
+int of_irq_map_one(struct device_node *device, int index, struct of_irq *out_irq)
+{
+        struct device_node *p;
+        u32 *intspec, *tmp, intsize, intlen, *addr;
+        int res;
+
+        DBG("of_irq_map_one: dev=%s, index=%d\n", device->full_name, index);
+
+        /* OldWorld mac stuff is "special", handle out of line */
+        if (of_irq_workarounds & OF_IMAP_OLDWORLD_MAC)
+                return of_irq_map_oldworld(device, index, out_irq);
+
+        /* Get the interrupts property */
+        intspec = (u32 *)get_property(device, "interrupts", &intlen);
+        if (intspec == NULL)
+                return -EINVAL;
+        intlen /= sizeof(u32);
+
+        /* Get the reg property (if any) */
+        addr = (u32 *)get_property(device, "reg", NULL);
+
+        /* Look for the interrupt parent. */
+        p = of_irq_find_parent(device);
+        if (p == NULL)
+                return -EINVAL;
+
+        /* Get size of interrupt specifier */
+        tmp = (u32 *)get_property(p, "#interrupt-cells", NULL);
+        if (tmp == NULL) {
+                of_node_put(p);
+                return -EINVAL;
+        }
+        intsize = *tmp;
+
+        /* Check index */
+        if (index * intsize >= intlen)
+                return -EINVAL;
+
+        /* Get new specifier and map it */
+        res = of_irq_map_raw(p, intspec + index * intsize, addr, out_irq);
+        of_node_put(p);
+        return res;
+}
+EXPORT_SYMBOL_GPL(of_irq_map_one);
+
+int of_irq_map_pci(struct pci_dev *pdev, struct of_irq *out_irq)
+{
+        struct device_node *dn, *ppnode;
+        struct pci_dev *ppdev;
+        u32 lspec;
+        u32 laddr[3];
+        u8 pin;
+        int rc;
+
+        /* Check if we have a device node, if yes, fallback to standard OF
+         * parsing
+         */
+        dn = pci_device_to_OF_node(pdev);
+        if (dn)
+                return of_irq_map_one(dn, 0, out_irq);
+
+        /* Ok, we don't, time to have fun. Let's start by building up an
+         * interrupt spec.  we assume #interrupt-cells is 1, which is standard
+         * for PCI. If you do different, then don't use that routine.
+         */
+        rc = pci_read_config_byte(pdev, PCI_INTERRUPT_PIN, &pin);
+        if (rc != 0)
+                return rc;
+        /* No pin, exit */
+        if (pin == 0)
+                return -ENODEV;
+
+        /* Now we walk up the PCI tree */
+        lspec = pin;
+        for (;;) {
+                /* Get the pci_dev of our parent */
+                ppdev = pdev->bus->self;
+
+                /* Ouch, it's a host bridge... */
+                if (ppdev == NULL) {
+#ifdef CONFIG_PPC64
+                        ppnode = pci_bus_to_OF_node(pdev->bus);
+#else
+                        struct pci_controller *host;
+                        host = pci_bus_to_host(pdev->bus);
+                        ppnode = host ? host->arch_data : NULL;
+#endif
+                        /* No node for host bridge ? give up */
+                        if (ppnode == NULL)
+                                return -EINVAL;
+                } else
+                        /* We found a P2P bridge, check if it has a node */
+                        ppnode = pci_device_to_OF_node(ppdev);
+
+                /* Ok, we have found a parent with a device-node, hand over to
+                 * the OF parsing code.
+                 * We build a unit address from the linux device to be used for
+                 * resolution. Note that we use the linux bus number which may
+                 * not match your firmware bus numbering.
+                 * Fortunately, in most cases, interrupt-map-mask doesn't include
+                 * the bus number as part of the matching.
+                 * You should still be careful about that though if you intend
+                 * to rely on this function (you ship  a firmware that doesn't
+                 * create device nodes for all PCI devices).
+                 */
+                if (ppnode)
+                        break;
+
+                /* We can only get here if we hit a P2P bridge with no node,
+                 * let's do standard swizzling and try again
+                 */
+                lspec = of_irq_pci_swizzle(PCI_SLOT(pdev->devfn), lspec);
+                pdev = ppdev;
+        }
+
+        laddr[0] = (pdev->bus->number << 16)
+                | (pdev->devfn << 8);
+        laddr[1]  = laddr[2] = 0;
+        return of_irq_map_raw(ppnode, &lspec, laddr, out_irq);
+}
+EXPORT_SYMBOL_GPL(of_irq_map_pci);
+