[POWERPC] New device-tree interrupt parsing code
authorBenjamin Herrenschmidt <benh@kernel.crashing.org>
Mon, 3 Jul 2006 09:35:17 +0000 (19:35 +1000)
committerPaul Mackerras <paulus@samba.org>
Mon, 3 Jul 2006 09:55:24 +0000 (19:55 +1000)
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>
arch/powerpc/kernel/prom_parse.c
include/asm-powerpc/prom.h

index 45df420..21009b1 100644 (file)
@@ -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);
+
index b0768f4..48bef40 100644 (file)
@@ -204,6 +204,15 @@ extern int release_OF_resource(struct device_node* node, int index);
  */
 
 
+/* Helper to read a big number */
+static inline u64 of_read_number(u32 *cell, int size)
+{
+       u64 r = 0;
+       while (size--)
+               r = (r << 32) | *(cell++);
+       return r;
+}
+
 /* Translate an OF address block into a CPU physical address
  */
 #define OF_BAD_ADDR    ((u64)-1)
@@ -240,5 +249,83 @@ extern void kdump_move_device_tree(void);
 /* CPU OF node matching */
 struct device_node *of_get_cpu_node(int cpu, unsigned int *thread);
 
+
+/*
+ * OF interrupt mapping
+ */
+
+/* This structure is returned when an interrupt is mapped. The controller
+ * field needs to be put() after use
+ */
+
+#define OF_MAX_IRQ_SPEC                 4 /* We handle specifiers of at most 4 cells */
+
+struct of_irq {
+       struct device_node *controller; /* Interrupt controller node */
+       u32 size;                       /* Specifier size */
+       u32 specifier[OF_MAX_IRQ_SPEC]; /* Specifier copy */
+};
+
+/***
+ * of_irq_map_init - Initialize the irq remapper
+ * @flags:     flags defining workarounds to enable
+ *
+ * Some machines have bugs in the device-tree which require certain workarounds
+ * to be applied. Call this before any interrupt mapping attempts to enable
+ * those workarounds.
+ */
+#define OF_IMAP_OLDWORLD_MAC   0x00000001
+#define OF_IMAP_NO_PHANDLE     0x00000002
+
+extern void of_irq_map_init(unsigned int flags);
+
+/***
+ * of_irq_map_raw - Low level interrupt tree parsing
+ * @parent:    the device interrupt parent
+ * @intspec:   interrupt specifier ("interrupts" property of the device)
+ * @addr:      address specifier (start of "reg" property of the device)
+ * @out_irq:   structure of_irq filled by this function
+ *
+ * Returns 0 on success and a negative number on error
+ *
+ * This function is a low-level interrupt tree walking function. It
+ * can be used to do a partial walk with synthetized reg and interrupts
+ * properties, for example when resolving PCI interrupts when no device
+ * node exist for the parent.
+ *
+ */
+
+extern int of_irq_map_raw(struct device_node *parent, u32 *intspec, u32 *addr,
+                         struct of_irq *out_irq);
+
+
+/***
+ * of_irq_map_one - Resolve an interrupt for a device
+ * @device:    the device whose interrupt is to be resolved
+ * @index:             index of the interrupt to resolve
+ * @out_irq:   structure of_irq filled by this function
+ *
+ * This function resolves an interrupt, walking the tree, for a given
+ * device-tree node. It's the high level pendant to of_irq_map_raw().
+ * It also implements the workarounds for OldWolrd Macs.
+ */
+extern int of_irq_map_one(struct device_node *device, int index,
+                         struct of_irq *out_irq);
+
+/***
+ * of_irq_map_pci - Resolve the interrupt for a PCI device
+ * @pdev:      the device whose interrupt is to be resolved
+ * @out_irq:   structure of_irq filled by this function
+ *
+ * This function resolves the PCI interrupt for a given PCI device. If a
+ * device-node exists for a given pci_dev, it will use normal OF tree
+ * walking. If not, it will implement standard swizzling and walk up the
+ * PCI tree until an device-node is found, at which point it will finish
+ * resolving using the OF tree walking.
+ */
+struct pci_dev;
+extern int of_irq_map_pci(struct pci_dev *pdev, struct of_irq *out_irq);
+
+
 #endif /* __KERNEL__ */
 #endif /* _POWERPC_PROM_H */