of/irq: Refactor interrupt-map parsing

All the users of of_irq_parse_raw pass in a raw interrupt specifier from
the device tree and expect it to be returned (possibly modified) in an
of_phandle_args structure. However, the primary function of
of_irq_parse_raw() is to check for translations due to the presence of
one or more interrupt-map properties. The actual placing of the data
into an of_phandle_args structure is trivial. If it is refactored to
accept an of_phandle_args structure directly, then it becomes possible
to consume of_phandle_args from other sources. This is important for an
upcoming patch that allows a device to be connected to more than one
interrupt parent. It also simplifies the code a bit.

The biggest complication with this patch is that the old version works
on the interrupt specifiers in __be32 form, but the of_phandle_args
structure is intended to carry it in the cpu-native version. A bit of
churn was required to make this work. In the end it results in tighter
code, so the churn is worth it.

Signed-off-by: Grant Likely <grant.likely@linaro.org>
Acked-by: Tony Lindgren <tony@atomide.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>

diff --git a/arch/powerpc/platforms/fsl_uli1575.c b/arch/powerpc/platforms/fsl_uli1575.c
index 8904046556ad544cc24dc827ae65fdbe391602c7..b97f6f3d3c5b33f9bbcb0e83ba2f25f1be10cefd 100644 (file)
--- a/arch/powerpc/platforms/fsl_uli1575.c
+++ b/arch/powerpc/platforms/fsl_uli1575.c
@@ -322,7 +322,6 @@ static void hpcd_final_uli5288(struct pci_dev *dev)
        struct pci_controller *hose = pci_bus_to_host(dev->bus);
        struct device_node *hosenode = hose ? hose->dn : NULL;
        struct of_phandle_args oirq;
-       int pin = 2;
        u32 laddr[3];
 
        if (!machine_is(mpc86xx_hpcd))
@@ -331,9 +330,12 @@ static void hpcd_final_uli5288(struct pci_dev *dev)
        if (!hosenode)
                return;
 
+       oirq.np = hosenode;
+       oirq.args[0] = 2;
+       oirq.args_count = 1;
        laddr[0] = (hose->first_busno << 16) | (PCI_DEVFN(31, 0) << 8);
        laddr[1] = laddr[2] = 0;
-       of_irq_parse_raw(hosenode, &pin, 1, laddr, &oirq);
+       of_irq_parse_raw(laddr, &oirq);
        dev->irq = irq_create_of_mapping(&oirq);
 }
 

diff --git a/drivers/of/irq.c b/drivers/of/irq.c
index 84184c44e8db3b2d4a1172da1faa27a31ed5ea0a..0ed5ed4a5f9bbcad2cac9cd2c597df131c7eae38 100644 (file)
--- a/drivers/of/irq.c
+++ b/drivers/of/irq.c
@@ -80,31 +80,32 @@ struct device_node *of_irq_find_parent(struct device_node *child)
 /**
  * of_irq_parse_raw - Low level interrupt tree parsing
  * @parent:    the device interrupt parent
- * @intspec:   interrupt specifier ("interrupts" property of the device)
- * @ointsize:   size of the passed in interrupt specifier
- * @addr:      address specifier (start of "reg" property of the device)
- * @out_irq:   structure of_irq filled by this function
+ * @addr:      address specifier (start of "reg" property of the device) in be32 format
+ * @out_irq:   structure of_irq updated 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.
+ * node exist for the parent. It takes an interrupt specifier structure as
+ * input, walks the tree looking for any interrupt-map properties, translates
+ * the specifier for each map, and then returns the translated map.
  */
-int of_irq_parse_raw(struct device_node *parent, const __be32 *intspec,
-                  u32 ointsize, const __be32 *addr, struct of_phandle_args *out_irq)
+int of_irq_parse_raw(const __be32 *addr, struct of_phandle_args *out_irq)
 {
        struct device_node *ipar, *tnode, *old = NULL, *newpar = NULL;
-       const __be32 *tmp, *imap, *imask;
+       __be32 initial_match_array[8];
+       const __be32 *match_array = initial_match_array;
+       const __be32 *tmp, *imap, *imask, dummy_imask[] = { ~0, ~0, ~0, ~0, ~0 };
        u32 intsize = 1, addrsize, newintsize = 0, newaddrsize = 0;
        int imaplen, match, i;
 
        pr_debug("of_irq_parse_raw: par=%s,intspec=[0x%08x 0x%08x...],ointsize=%d\n",
-                of_node_full_name(parent), be32_to_cpup(intspec),
-                be32_to_cpup(intspec + 1), ointsize);
+                of_node_full_name(out_irq->np), out_irq->args[0], out_irq->args[1],
+                out_irq->args_count);
 
-       ipar = of_node_get(parent);
+       ipar = of_node_get(out_irq->np);
 
        /* First get the #interrupt-cells property of the current cursor
         * that tells us how to interpret the passed-in intspec. If there
@@ -127,7 +128,7 @@ int of_irq_parse_raw(struct device_node *parent, const __be32 *intspec,
 
        pr_debug("of_irq_parse_raw: ipar=%s, size=%d\n", of_node_full_name(ipar), intsize);
 
-       if (ointsize != intsize)
+       if (out_irq->args_count != intsize)
                return -EINVAL;
 
        /* Look for this #address-cells. We have to implement the old linux
@@ -146,6 +147,21 @@ int of_irq_parse_raw(struct device_node *parent, const __be32 *intspec,
 
        pr_debug(" -> addrsize=%d\n", addrsize);
 
+       /* 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) {
+               pr_debug(" -> no reg passed in when needed !\n");
+               return -EINVAL;
+       }
+
+       /* Precalculate the match array - this simplifies match loop */
+       for (i = 0; i < addrsize; i++)
+               initial_match_array[i] = addr[i];
+       for (i = 0; i < intsize; i++)
+               initial_match_array[addrsize + i] = cpu_to_be32(out_irq->args[i]);
+
        /* 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
@@ -154,11 +170,6 @@ int of_irq_parse_raw(struct device_node *parent, const __be32 *intspec,
                if (of_get_property(ipar, "interrupt-controller", NULL) !=
                                NULL) {
                        pr_debug(" -> got it !\n");
-                       for (i = 0; i < intsize; i++)
-                               out_irq->args[i] =
-                                               of_read_number(intspec +i, 1);
-                       out_irq->args_count = intsize;
-                       out_irq->np = ipar;
                        of_node_put(old);
                        return 0;
                }
@@ -175,34 +186,16 @@ int of_irq_parse_raw(struct device_node *parent, const __be32 *intspec,
 
                /* Look for a mask */
                imask = of_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) {
-                       pr_debug(" -> no reg passed in when needed !\n");
-                       goto fail;
-               }
+               if (!imask)
+                       imask = dummy_imask;
 
                /* Parse interrupt-map */
                match = 0;
                while (imaplen > (addrsize + intsize + 1) && !match) {
                        /* Compare specifiers */
                        match = 1;
-                       for (i = 0; i < addrsize && match; ++i) {
-                               __be32 mask = imask ? imask[i]
-                                                   : cpu_to_be32(0xffffffffu);
-                               match = ((addr[i] ^ imap[i]) & mask) == 0;
-                       }
-                       for (; i < (addrsize + intsize) && match; ++i) {
-                               __be32 mask = imask ? imask[i]
-                                                   : cpu_to_be32(0xffffffffu);
-                               match =
-                                  ((intspec[i-addrsize] ^ imap[i]) & mask) == 0;
-                       }
-                       imap += addrsize + intsize;
-                       imaplen -= addrsize + intsize;
+                       for (i = 0; i < (addrsize + intsize); i++, imaplen--)
+                               match = !((match_array[i] ^ *imap++) & imask[i]);
 
                        pr_debug(" -> match=%d (imaplen=%d)\n", match, imaplen);
 
@@ -247,12 +240,18 @@ int of_irq_parse_raw(struct device_node *parent, const __be32 *intspec,
                if (!match)
                        goto fail;
 
-               of_node_put(old);
-               old = of_node_get(newpar);
+               /*
+                * Successfully parsed an interrrupt-map translation; copy new
+                * interrupt specifier into the out_irq structure
+                */
+               of_node_put(out_irq->np);
+               out_irq->np = of_node_get(newpar);
+
+               match_array = imap - newaddrsize - newintsize;
+               for (i = 0; i < newintsize; i++)
+                       out_irq->args[i] = be32_to_cpup(imap - newintsize + i);
+               out_irq->args_count = intsize = newintsize;
                addrsize = newaddrsize;
-               intsize = newintsize;
-               intspec = imap - intsize;
-               addr = intspec - addrsize;
 
        skiplevel:
                /* Iterate again with new parent */
@@ -263,7 +262,7 @@ int of_irq_parse_raw(struct device_node *parent, const __be32 *intspec,
        }
  fail:
        of_node_put(ipar);
-       of_node_put(old);
+       of_node_put(out_irq->np);
        of_node_put(newpar);
 
        return -EINVAL;
@@ -276,15 +275,16 @@ EXPORT_SYMBOL_GPL(of_irq_parse_raw);
  * @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_parse_raw().
+ * This function resolves an interrupt for a node by walking the interrupt tree,
+ * finding which interrupt controller node it is attached to, and returning the
+ * interrupt specifier that can be used to retrieve a Linux IRQ number.
  */
 int of_irq_parse_one(struct device_node *device, int index, struct of_phandle_args *out_irq)
 {
        struct device_node *p;
        const __be32 *intspec, *tmp, *addr;
        u32 intsize, intlen;
-       int res = -EINVAL;
+       int i, res = -EINVAL;
 
        pr_debug("of_irq_parse_one: dev=%s, index=%d\n", of_node_full_name(device), index);
 
@@ -320,9 +320,15 @@ int of_irq_parse_one(struct device_node *device, int index, struct of_phandle_ar
        if ((index + 1) * intsize > intlen)
                goto out;
 
-       /* Get new specifier and map it */
-       res = of_irq_parse_raw(p, intspec + index * intsize, intsize,
-                            addr, out_irq);
+       /* Copy intspec into irq structure */
+       intspec += index * intsize;
+       out_irq->np = p;
+       out_irq->args_count = intsize;
+       for (i = 0; i < intsize; i++)
+               out_irq->args[i] = be32_to_cpup(intspec++);
+
+       /* Check if there are any interrupt-map translations to process */
+       res = of_irq_parse_raw(addr, out_irq);
  out:
        of_node_put(p);
        return res;

diff --git a/drivers/of/of_pci_irq.c b/drivers/of/of_pci_irq.c
index ee3293d4b66bd0a05290d8a7372e748f6718e107..303afebc247a63fbb8a4712d9100e5e33c2b8ee4 100644 (file)
--- a/drivers/of/of_pci_irq.c
+++ b/drivers/of/of_pci_irq.c
@@ -85,9 +85,12 @@ int of_irq_parse_pci(const struct pci_dev *pdev, struct of_phandle_args *out_irq
                pdev = ppdev;
        }
 
+       out_irq->np = ppnode;
+       out_irq->args_count = 1;
+       out_irq->args[0] = lspec;
        lspec_be = cpu_to_be32(lspec);
        laddr[0] = cpu_to_be32((pdev->bus->number << 16) | (pdev->devfn << 8));
-       laddr[1]  = laddr[2] = cpu_to_be32(0);
-       return of_irq_parse_raw(ppnode, &lspec_be, 1, laddr, out_irq);
+       laddr[1] = laddr[2] = cpu_to_be32(0);
+       return of_irq_parse_raw(laddr, out_irq);
 }
 EXPORT_SYMBOL_GPL(of_irq_parse_pci);

diff --git a/include/linux/of_irq.h b/include/linux/of_irq.h
index 3bbba8d6adc81911db90b8493dcaac9fb3e383e5..c0d6dfe808951b0774a89edcaf31190e4655d236 100644 (file)
--- a/include/linux/of_irq.h
+++ b/include/linux/of_irq.h
@@ -31,10 +31,7 @@ static inline int of_irq_parse_oldworld(struct device_node *device, int index,
 }
 #endif /* CONFIG_PPC32 && CONFIG_PPC_PMAC */
 
-
-extern int of_irq_parse_raw(struct device_node *parent, const __be32 *intspec,
-                         u32 ointsize, const __be32 *addr,
-                         struct of_phandle_args *out_irq);
+extern int of_irq_parse_raw(const __be32 *addr, struct of_phandle_args *out_irq);
 extern int of_irq_parse_one(struct device_node *device, int index,
                          struct of_phandle_args *out_irq);
 extern unsigned int irq_create_of_mapping(struct of_phandle_args *irq_data);