[POWERPC] Add new interrupt mapping core and change platforms to use it

This adds the new irq remapper core and removes the old one.  Because
there are some fundamental conflicts with the old code, like the value
of NO_IRQ which I'm now setting to 0 (as per discussions with Linus),
etc..., this commit also changes the relevant platform and driver code
over to use the new remapper (so as not to cause difficulties later
in bisecting).

This patch removes the old pre-parsing of the open firmware interrupt
tree along with all the bogus assumptions it made to try to renumber
interrupts according to the platform. This is all to be handled by the
new code now.

For the pSeries XICS interrupt controller, a single remapper host is
created for the whole machine regardless of how many interrupt
presentation and source controllers are found, and it's set to match
any device node that isn't a 8259.  That works fine on pSeries and
avoids having to deal with some of the complexities of split source
controllers vs. presentation controllers in the pSeries device trees.

The powerpc i8259 PIC driver now always requests the legacy interrupt
range. It also has the feature of being able to match any device node
(including NULL) if passed no device node as an input. That will help
porting over platforms with broken device-trees like Pegasos who don't
have a proper interrupt tree.

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

1 files changed, 174 insertions, 222 deletions

diff --git a/arch/powerpc/platforms/cell/interrupt.c b/arch/powerpc/platforms/cell/interrupt.c
index 97936f547f19..9d5da7896892 100644
--- a/arch/powerpc/platforms/cell/interrupt.c
+++ b/arch/powerpc/platforms/cell/interrupt.c
@@ -1,6 +1,9 @@
 /*
  * Cell Internal Interrupt Controller
  *
+ * Copyright (C) 2006 Benjamin Herrenschmidt (benh@kernel.crashing.org)
+ *                    IBM, Corp.
+ *
  * (C) Copyright IBM Deutschland Entwicklung GmbH 2005
  *
  * Author: Arnd Bergmann <arndb@de.ibm.com>
@@ -25,11 +28,13 @@
 #include <linux/module.h>
 #include <linux/percpu.h>
 #include <linux/types.h>
+#include <linux/ioport.h>
 
 #include <asm/io.h>
 #include <asm/pgtable.h>
 #include <asm/prom.h>
 #include <asm/ptrace.h>
+#include <asm/machdep.h>
 
 #include "interrupt.h"
 #include "cbe_regs.h"
@@ -39,9 +44,25 @@ struct iic {
         u8 target_id;
         u8 eoi_stack[16];
         int eoi_ptr;
+        struct irq_host *host;
 };
 
 static DEFINE_PER_CPU(struct iic, iic);
+#define IIC_NODE_COUNT  2
+static struct irq_host *iic_hosts[IIC_NODE_COUNT];
+
+/* Convert between "pending" bits and hw irq number */
+static irq_hw_number_t iic_pending_to_hwnum(struct cbe_iic_pending_bits bits)
+{
+        unsigned char unit = bits.source & 0xf;
+
+        if (bits.flags & CBE_IIC_IRQ_IPI)
+                return IIC_IRQ_IPI0 | (bits.prio >> 4);
+        else if (bits.class <= 3)
+                return (bits.class << 4) | unit;
+        else
+                return IIC_IRQ_INVALID;
+}
 
 static void iic_mask(unsigned int irq)
 {
@@ -65,197 +86,21 @@ static struct irq_chip iic_chip = {
         .eoi = iic_eoi,
 };
 
-/* XXX All of this has to be reworked completely. We need to assign a real
- * interrupt numbers to the external interrupts and remove all the hard coded
- * interrupt maps (rely on the device-tree whenever possible).
- *
- * Basically, my scheme is to define the "pendings" bits to be the HW interrupt
- * number (ignoring the data and flags here). That means we can sort-of split
- * external sources based on priority, and we can use request_irq() on pretty
- * much anything.
- *
- * For spider or axon, they have their own interrupt space. spider will just have
- * local "hardward" interrupts 0...xx * node stride. The node stride is not
- * necessary (separate interrupt chips will have separate HW number space), but
- * will allow to be compatible with existing device-trees.
- *
- * All of thise little world will get a standard remapping scheme to map those HW
- * numbers into the linux flat irq number space.
-*/
-static int iic_external_get_irq(struct cbe_iic_pending_bits pending)
-{
-        int irq;
-        unsigned char node, unit;
-
-        node = pending.source >> 4;
-        unit = pending.source & 0xf;
-        irq = -1;
-
-        /*
-         * This mapping is specific to the Cell Broadband
-         * Engine. We might need to get the numbers
-         * from the device tree to support future CPUs.
-         */
-        switch (unit) {
-        case 0x00:
-        case 0x0b:
-                /*
-                 * One of these units can be connected
-                 * to an external interrupt controller.
-                 */
-                if (pending.class != 2)
-                        break;
-                /* TODO: We might want to silently ignore cascade interrupts
-                 * when no cascade handler exist yet
-                 */
-                irq = IIC_EXT_CASCADE + node * IIC_NODE_STRIDE;
-                break;
-        case 0x01 ... 0x04:
-        case 0x07 ... 0x0a:
-                /*
-                 * These units are connected to the SPEs
-                 */
-                if (pending.class > 2)
-                        break;
-                irq = IIC_SPE_OFFSET
-                        + pending.class * IIC_CLASS_STRIDE
-                        + node * IIC_NODE_STRIDE
-                        + unit;
-                break;
-        }
-        if (irq == -1)
-                printk(KERN_WARNING "Unexpected interrupt class %02x, "
-                        "source %02x, prio %02x, cpu %02x\n", pending.class,
-                        pending.source, pending.prio, smp_processor_id());
-        return irq;
-}
-
 /* Get an IRQ number from the pending state register of the IIC */
-int iic_get_irq(struct pt_regs *regs)
-{
-        struct iic *iic;
-        int irq;
-        struct cbe_iic_pending_bits pending;
-
-        iic = &__get_cpu_var(iic);
-        *(unsigned long *) &pending = 
-                in_be64((unsigned long __iomem *) &iic->regs->pending_destr);
-        iic->eoi_stack[++iic->eoi_ptr] = pending.prio;
-        BUG_ON(iic->eoi_ptr > 15);
-
-        irq = -1;
-        if (pending.flags & CBE_IIC_IRQ_VALID) {
-                if (pending.flags & CBE_IIC_IRQ_IPI) {
-                        irq = IIC_IPI_OFFSET + (pending.prio >> 4);
-/*
-                        if (irq > 0x80)
-                                printk(KERN_WARNING "Unexpected IPI prio %02x"
-                                        "on CPU %02x\n", pending.prio,
-                                                        smp_processor_id());
-*/
-                } else {
-                        irq = iic_external_get_irq(pending);
-                }
-        }
-        return irq;
-}
-
-/* hardcoded part to be compatible with older firmware */
-
-static int __init setup_iic_hardcoded(void)
-{
-        struct device_node *np;
-        int nodeid, cpu;
-        unsigned long regs;
-        struct iic *iic;
-
-        for_each_possible_cpu(cpu) {
-                iic = &per_cpu(iic, cpu);
-                nodeid = cpu/2;
-
-                for (np = of_find_node_by_type(NULL, "cpu");
-                     np;
-                     np = of_find_node_by_type(np, "cpu")) {
-                        if (nodeid == *(int *)get_property(np, "node-id", NULL))
-                                break;
-                        }
-
-                if (!np) {
-                        printk(KERN_WARNING "IIC: CPU %d not found\n", cpu);
-                        iic->regs = NULL;
-                        iic->target_id = 0xff;
-                        return -ENODEV;
-                        }
-
-                regs = *(long *)get_property(np, "iic", NULL);
-
-                /* hack until we have decided on the devtree info */
-                regs += 0x400;
-                if (cpu & 1)
-                        regs += 0x20;
-
-                printk(KERN_INFO "IIC for CPU %d at %lx\n", cpu, regs);
-                iic->regs = ioremap(regs, sizeof(struct cbe_iic_thread_regs));
-                iic->target_id = (nodeid << 4) + ((cpu & 1) ? 0xf : 0xe);
-                iic->eoi_stack[0] = 0xff;
-        }
-
-        return 0;
-}
-
-static int __init setup_iic(void)
+static unsigned int iic_get_irq(struct pt_regs *regs)
 {
-        struct device_node *dn;
-        unsigned long *regs;
-        char *compatible;
-        unsigned *np, found = 0;
-        struct iic *iic = NULL;
-
-        for (dn = NULL; (dn = of_find_node_by_name(dn, "interrupt-controller"));) {
-                compatible = (char *)get_property(dn, "compatible", NULL);
-
-                if (!compatible) {
-                        printk(KERN_WARNING "no compatible property found !\n");
-                        continue;
-                }
-
-                if (strstr(compatible, "IBM,CBEA-Internal-Interrupt-Controller"))
-                        regs = (unsigned long *)get_property(dn,"reg", NULL);
-                else
-                        continue;
-
-                if (!regs)
-                        printk(KERN_WARNING "IIC: no reg property\n");
-
-                np = (unsigned int *)get_property(dn, "ibm,interrupt-server-ranges", NULL);
-
-                if (!np) {
-                        printk(KERN_WARNING "IIC: CPU association not found\n");
-                        iic->regs = NULL;
-                        iic->target_id = 0xff;
-                        return -ENODEV;
-                }
-
-                iic = &per_cpu(iic, np[0]);
-                iic->regs = ioremap(regs[0], sizeof(struct cbe_iic_thread_regs));
-                iic->target_id = ((np[0] & 2) << 3) + ((np[0] & 1) ? 0xf : 0xe);
-                iic->eoi_stack[0] = 0xff;
-                printk("IIC for CPU %d at %lx mapped to %p\n", np[0], regs[0], iic->regs);
-
-                iic = &per_cpu(iic, np[1]);
-                iic->regs = ioremap(regs[2], sizeof(struct cbe_iic_thread_regs));
-                iic->target_id = ((np[1] & 2) << 3) + ((np[1] & 1) ? 0xf : 0xe);
-                iic->eoi_stack[0] = 0xff;
-
-                printk("IIC for CPU %d at %lx mapped to %p\n", np[1], regs[2], iic->regs);
-
-                found++;
-        }
-
-        if (found)
-                return 0;
-        else
-                return -ENODEV;
+        struct cbe_iic_pending_bits pending;
+        struct iic *iic;
+
+        iic = &__get_cpu_var(iic);
+        *(unsigned long *) &pending =
+                in_be64((unsigned long __iomem *) &iic->regs->pending_destr);
+        iic->eoi_stack[++iic->eoi_ptr] = pending.prio;
+        BUG_ON(iic->eoi_ptr > 15);
+        if (pending.flags & CBE_IIC_IRQ_VALID)
+                return irq_linear_revmap(iic->host,
+                                         iic_pending_to_hwnum(pending));
+        return NO_IRQ;
 }
 
 #ifdef CONFIG_SMP
@@ -263,12 +108,12 @@ static int __init setup_iic(void)
 /* Use the highest interrupt priorities for IPI */
 static inline int iic_ipi_to_irq(int ipi)
 {
-        return IIC_IPI_OFFSET + IIC_NUM_IPIS - 1 - ipi;
+        return IIC_IRQ_IPI0 + IIC_NUM_IPIS - 1 - ipi;
 }
 
 static inline int iic_irq_to_ipi(int irq)
 {
-        return IIC_NUM_IPIS - 1 - (irq - IIC_IPI_OFFSET);
+        return IIC_NUM_IPIS - 1 - (irq - IIC_IRQ_IPI0);
 }
 
 void iic_setup_cpu(void)
@@ -287,22 +132,51 @@ u8 iic_get_target_id(int cpu)
 }
 EXPORT_SYMBOL_GPL(iic_get_target_id);
 
+struct irq_host *iic_get_irq_host(int node)
+{
+        if (node < 0 || node >= IIC_NODE_COUNT)
+                return NULL;
+        return iic_hosts[node];
+}
+EXPORT_SYMBOL_GPL(iic_get_irq_host);
+
+
 static irqreturn_t iic_ipi_action(int irq, void *dev_id, struct pt_regs *regs)
 {
-        smp_message_recv(iic_irq_to_ipi(irq), regs);
+        int ipi = (int)(long)dev_id;
+
+        smp_message_recv(ipi, regs);
+
         return IRQ_HANDLED;
 }
 
 static void iic_request_ipi(int ipi, const char *name)
 {
-        int irq;
+        int node, virq;
 
-        irq = iic_ipi_to_irq(ipi);
-
-        /* IPIs are marked IRQF_DISABLED as they must run with irqs
-         * disabled */
-        set_irq_chip_and_handler(irq, &iic_chip, handle_percpu_irq);
-        request_irq(irq, iic_ipi_action, IRQF_DISABLED, name, NULL);
+        for (node = 0; node < IIC_NODE_COUNT; node++) {
+                char *rname;
+                if (iic_hosts[node] == NULL)
+                        continue;
+                virq = irq_create_mapping(iic_hosts[node],
+                                          iic_ipi_to_irq(ipi), 0);
+                if (virq == NO_IRQ) {
+                        printk(KERN_ERR
+                               "iic: failed to map IPI %s on node %d\n",
+                               name, node);
+                        continue;
+                }
+                rname = kzalloc(strlen(name) + 16, GFP_KERNEL);
+                if (rname)
+                        sprintf(rname, "%s node %d", name, node);
+                else
+                        rname = (char *)name;
+                if (request_irq(virq, iic_ipi_action, IRQF_DISABLED,
+                                rname, (void *)(long)ipi))
+                        printk(KERN_ERR
+                               "iic: failed to request IPI %s on node %d\n",
+                               name, node);
+        }
 }
 
 void iic_request_IPIs(void)
@@ -313,41 +187,119 @@ void iic_request_IPIs(void)
         iic_request_ipi(PPC_MSG_DEBUGGER_BREAK, "IPI-debug");
 #endif /* CONFIG_DEBUGGER */
 }
+
 #endif /* CONFIG_SMP */
 
-static void __init iic_setup_builtin_handlers(void)
+
+static int iic_host_match(struct irq_host *h, struct device_node *node)
+{
+        return h->host_data != NULL && node == h->host_data;
+}
+
+static int iic_host_map(struct irq_host *h, unsigned int virq,
+                        irq_hw_number_t hw, unsigned int flags)
+{
+        if (hw < IIC_IRQ_IPI0)
+                set_irq_chip_and_handler(virq, &iic_chip, handle_fasteoi_irq);
+        else
+                set_irq_chip_and_handler(virq, &iic_chip, handle_percpu_irq);
+        return 0;
+}
+
+static int iic_host_xlate(struct irq_host *h, struct device_node *ct,
+                           u32 *intspec, unsigned int intsize,
+                           irq_hw_number_t *out_hwirq, unsigned int *out_flags)
+
 {
-        int be, isrc;
+        /* Currently, we don't translate anything. That needs to be fixed as
+         * we get better defined device-trees. iic interrupts have to be
+         * explicitely mapped by whoever needs them
+         */
+        return -ENODEV;
+}
+
+static struct irq_host_ops iic_host_ops = {
+        .match = iic_host_match,
+        .map = iic_host_map,
+        .xlate = iic_host_xlate,
+};
+
+static void __init init_one_iic(unsigned int hw_cpu, unsigned long addr,
+                                struct irq_host *host)
+{
+        /* XXX FIXME: should locate the linux CPU number from the HW cpu
+         * number properly. We are lucky for now
+         */
+        struct iic *iic = &per_cpu(iic, hw_cpu);
 
-        /* XXX FIXME: Assume two threads per BE are present */
-        for (be=0; be < num_present_cpus() / 2; be++) {
-                int irq;
+        iic->regs = ioremap(addr, sizeof(struct cbe_iic_thread_regs));
+        BUG_ON(iic->regs == NULL);
 
-                /* setup SPE chip and handlers */
-                for (isrc = 0; isrc < IIC_CLASS_STRIDE * 3; isrc++) {
-                        irq = IIC_NODE_STRIDE * be + IIC_SPE_OFFSET + isrc;
-                        set_irq_chip_and_handler(irq, &iic_chip, handle_fasteoi_irq);
+        iic->target_id = ((hw_cpu & 2) << 3) | ((hw_cpu & 1) ? 0xf : 0xe);
+        iic->eoi_stack[0] = 0xff;
+        iic->host = host;
+        out_be64(&iic->regs->prio, 0);
+
+        printk(KERN_INFO "IIC for CPU %d at %lx mapped to %p, target id 0x%x\n",
+               hw_cpu, addr, iic->regs, iic->target_id);
+}
+
+static int __init setup_iic(void)
+{
+        struct device_node *dn;
+        struct resource r0, r1;
+        struct irq_host *host;
+        int found = 0;
+        u32 *np;
+
+        for (dn = NULL;
+             (dn = of_find_node_by_name(dn,"interrupt-controller")) != NULL;) {
+                if (!device_is_compatible(dn,
+                                     "IBM,CBEA-Internal-Interrupt-Controller"))
+                        continue;
+                np = (u32 *)get_property(dn, "ibm,interrupt-server-ranges",
+                                         NULL);
+                if (np == NULL) {
+                        printk(KERN_WARNING "IIC: CPU association not found\n");
+                        of_node_put(dn);
+                        return -ENODEV;
                 }
-                /* setup cascade chip */
-                irq = IIC_EXT_CASCADE + be * IIC_NODE_STRIDE;
-                set_irq_chip_and_handler(irq, &iic_chip, handle_fasteoi_irq);
+                if (of_address_to_resource(dn, 0, &r0) ||
+                    of_address_to_resource(dn, 1, &r1)) {
+                        printk(KERN_WARNING "IIC: Can't resolve addresses\n");
+                        of_node_put(dn);
+                        return -ENODEV;
+                }
+                host = NULL;
+                if (found < IIC_NODE_COUNT) {
+                        host = irq_alloc_host(IRQ_HOST_MAP_LINEAR,
+                                              IIC_SOURCE_COUNT,
+                                              &iic_host_ops,
+                                              IIC_IRQ_INVALID);
+                        iic_hosts[found] = host;
+                        BUG_ON(iic_hosts[found] == NULL);
+                        iic_hosts[found]->host_data = of_node_get(dn);
+                        found++;
+                }
+                init_one_iic(np[0], r0.start, host);
+                init_one_iic(np[1], r1.start, host);
         }
+
+        if (found)
+                return 0;
+        else
+                return -ENODEV;
 }
 
 void __init iic_init_IRQ(void)
 {
-        int cpu, irq_offset;
-        struct iic *iic;
-
+        /* Discover and initialize iics */
         if (setup_iic() < 0)
-                setup_iic_hardcoded();
+                panic("IIC: Failed to initialize !\n");
 
-        irq_offset = 0;
-        for_each_possible_cpu(cpu) {
-                iic = &per_cpu(iic, cpu);
-                if (iic->regs)
-                        out_be64(&iic->regs->prio, 0xff);
-        }
-        iic_setup_builtin_handlers();
+        /* Set master interrupt handling function */
+        ppc_md.get_irq = iic_get_irq;
 
+        /* Enable on current CPU */
+        iic_setup_cpu();
 }