1 files changed, 112 insertions, 29 deletions

diff --git a/arch/powerpc/sysdev/i8259.c b/arch/powerpc/sysdev/i8259.c
index c2e9465871aa..72c73a6105cd 100644
--- a/arch/powerpc/sysdev/i8259.c
+++ b/arch/powerpc/sysdev/i8259.c
@@ -6,11 +6,16 @@
  * as published by the Free Software Foundation; either version
  * 2 of the License, or (at your option) any later version.
  */
+#undef DEBUG
+
 #include <linux/init.h>
 #include <linux/ioport.h>
 #include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
 #include <asm/io.h>
 #include <asm/i8259.h>
+#include <asm/prom.h>
 
 static volatile void __iomem *pci_intack; /* RO, gives us the irq vector */
 
@@ -20,7 +25,8 @@ static unsigned char cached_8259[2] = { 0xff, 0xff };
 
 static DEFINE_SPINLOCK(i8259_lock);
 
-static int i8259_pic_irq_offset;
+static struct device_node *i8259_node;
+static struct irq_host *i8259_host;
 
 /*
  * Acknowledge the IRQ using either the PCI host bridge's interrupt
@@ -28,16 +34,18 @@ static int i8259_pic_irq_offset;
  * which is called.  It should be noted that polling is broken on some
  * IBM and Motorola PReP boxes so we must use the int-ack feature on them.
  */
-int i8259_irq(struct pt_regs *regs)
+unsigned int i8259_irq(struct pt_regs *regs)
 {
         int irq;
-
-        spin_lock(&i8259_lock);
+        int lock = 0;
 
         /* Either int-ack or poll for the IRQ */
         if (pci_intack)
                 irq = readb(pci_intack);
         else {
+                spin_lock(&i8259_lock);
+                lock = 1;
+
                 /* Perform an interrupt acknowledge cycle on controller 1. */
                 outb(0x0C, 0x20);               /* prepare for poll */
                 irq = inb(0x20) & 7;
@@ -62,11 +70,13 @@ int i8259_irq(struct pt_regs *regs)
                 if (!pci_intack)
                         outb(0x0B, 0x20);       /* ISR register */
                 if(~inb(0x20) & 0x80)
-                        irq = -1;
-        }
+                        irq = NO_IRQ;
+        } else if (irq == 0xff)
+                irq = NO_IRQ;
 
-        spin_unlock(&i8259_lock);
-        return irq + i8259_pic_irq_offset;
+        if (lock)
+                spin_unlock(&i8259_lock);
+        return irq;
 }
 
 static void i8259_mask_and_ack_irq(unsigned int irq_nr)
@@ -74,7 +84,6 @@ static void i8259_mask_and_ack_irq(unsigned int irq_nr)
         unsigned long flags;
 
         spin_lock_irqsave(&i8259_lock, flags);
-        irq_nr -= i8259_pic_irq_offset;
         if (irq_nr > 7) {
                 cached_A1 |= 1 << (irq_nr-8);
                 inb(0xA1);      /* DUMMY */
@@ -100,8 +109,9 @@ static void i8259_mask_irq(unsigned int irq_nr)
 {
         unsigned long flags;
 
+        pr_debug("i8259_mask_irq(%d)\n", irq_nr);
+
         spin_lock_irqsave(&i8259_lock, flags);
-        irq_nr -= i8259_pic_irq_offset;
         if (irq_nr < 8)
                 cached_21 |= 1 << irq_nr;
         else
@@ -114,8 +124,9 @@ static void i8259_unmask_irq(unsigned int irq_nr)
 {
         unsigned long flags;
 
+        pr_debug("i8259_unmask_irq(%d)\n", irq_nr);
+
         spin_lock_irqsave(&i8259_lock, flags);
-        irq_nr -= i8259_pic_irq_offset;
         if (irq_nr < 8)
                 cached_21 &= ~(1 << irq_nr);
         else
@@ -152,25 +163,84 @@ static struct resource pic_edgectrl_iores = {
         .flags = IORESOURCE_BUSY,
 };
 
-static struct irqaction i8259_irqaction = {
-        .handler = no_action,
-        .flags = IRQF_DISABLED,
-        .mask = CPU_MASK_NONE,
-        .name = "82c59 secondary cascade",
+static int i8259_host_match(struct irq_host *h, struct device_node *node)
+{
+        return i8259_node == NULL || i8259_node == node;
+}
+
+static int i8259_host_map(struct irq_host *h, unsigned int virq,
+                          irq_hw_number_t hw, unsigned int flags)
+{
+        pr_debug("i8259_host_map(%d, 0x%lx)\n", virq, hw);
+
+        /* We block the internal cascade */
+        if (hw == 2)
+                get_irq_desc(virq)->status |= IRQ_NOREQUEST;
+
+        /* We use the level stuff only for now, we might want to
+         * be more cautious here but that works for now
+         */
+        get_irq_desc(virq)->status |= IRQ_LEVEL;
+        set_irq_chip_and_handler(virq, &i8259_pic, handle_level_irq);
+        return 0;
+}
+
+static void i8259_host_unmap(struct irq_host *h, unsigned int virq)
+{
+        /* Make sure irq is masked in hardware */
+        i8259_mask_irq(virq);
+
+        /* remove chip and handler */
+        set_irq_chip_and_handler(virq, NULL, NULL);
+
+        /* Make sure it's completed */
+        synchronize_irq(virq);
+}
+
+static int i8259_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)
+{
+        static unsigned char map_isa_senses[4] = {
+                IRQ_TYPE_LEVEL_LOW,
+                IRQ_TYPE_LEVEL_HIGH,
+                IRQ_TYPE_EDGE_FALLING,
+                IRQ_TYPE_EDGE_RISING,
+        };
+
+        *out_hwirq = intspec[0];
+        if (intsize > 1 && intspec[1] < 4)
+                *out_flags = map_isa_senses[intspec[1]];
+        else
+                *out_flags = IRQ_TYPE_NONE;
+
+        return 0;
+}
+
+static struct irq_host_ops i8259_host_ops = {
+        .match = i8259_host_match,
+        .map = i8259_host_map,
+        .unmap = i8259_host_unmap,
+        .xlate = i8259_host_xlate,
 };
 
-/*
- * i8259_init()
- * intack_addr - PCI interrupt acknowledge (real) address which will return
- *               the active irq from the 8259
+/****
+ * i8259_init - Initialize the legacy controller
+ * @node: device node of the legacy PIC (can be NULL, but then, it will match
+ *        all interrupts, so beware)
+ * @intack_addr: PCI interrupt acknowledge (real) address which will return
+ *               the active irq from the 8259
  */
-void __init i8259_init(unsigned long intack_addr, int offset)
+void i8259_init(struct device_node *node, unsigned long intack_addr)
 {
         unsigned long flags;
-        int i;
 
+        /* initialize the controller */
         spin_lock_irqsave(&i8259_lock, flags);
-        i8259_pic_irq_offset = offset;
+
+        /* Mask all first */
+        outb(0xff, 0xA1);
+        outb(0xff, 0x21);
 
         /* init master interrupt controller */
         outb(0x11, 0x20); /* Start init sequence */
@@ -184,24 +254,36 @@ void __init i8259_init(unsigned long intack_addr, int offset)
         outb(0x02, 0xA1); /* edge triggered, Cascade (slave) on IRQ2 */
         outb(0x01, 0xA1); /* Select 8086 mode */
 
+        /* That thing is slow */
+        udelay(100);
+
         /* always read ISR */
         outb(0x0B, 0x20);
         outb(0x0B, 0xA0);
 
-        /* Mask all interrupts */
+        /* Unmask the internal cascade */
+        cached_21 &= ~(1 << 2);
+
+        /* Set interrupt masks */
         outb(cached_A1, 0xA1);
         outb(cached_21, 0x21);
 
         spin_unlock_irqrestore(&i8259_lock, flags);
 
-        for (i = 0; i < NUM_ISA_INTERRUPTS; ++i) {
-                set_irq_chip_and_handler(offset + i, &i8259_pic,
-                                         handle_level_irq);
-                irq_desc[offset + i].status |= IRQ_LEVEL;
+        /* create a legacy host */
+        if (node)
+                i8259_node = of_node_get(node);
+        i8259_host = irq_alloc_host(IRQ_HOST_MAP_LEGACY, 0, &i8259_host_ops, 0);
+        if (i8259_host == NULL) {
+                printk(KERN_ERR "i8259: failed to allocate irq host !\n");
+                return;
         }
 
         /* reserve our resources */
-        setup_irq(offset + 2, &i8259_irqaction);
+        /* XXX should we continue doing that ? it seems to cause problems
+         * with further requesting of PCI IO resources for that range...
+         * need to look into it.
+         */
         request_resource(&ioport_resource, &pic1_iores);
         request_resource(&ioport_resource, &pic2_iores);
         request_resource(&ioport_resource, &pic_edgectrl_iores);
@@ -209,4 +291,5 @@ void __init i8259_init(unsigned long intack_addr, int offset)
         if (intack_addr != 0)
                 pci_intack = ioremap(intack_addr, 1);
 
+        printk(KERN_INFO "i8259 legacy interrupt controller initialized\n");
 }