[POWERPC] MPIC sys_device & suspend/resume

This adds mpic to the system devices and implements suspend
and resume for them.  This is necessary to get interrupts for
modules back to where they were before a suspend to disk.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

2 files changed, 110 insertions, 1 deletions

diff --git a/arch/powerpc/sysdev/mpic.c b/arch/powerpc/sysdev/mpic.c
index 57b1208ef1c3..e88bbd5ec4c8 100644
--- a/arch/powerpc/sysdev/mpic.c
+++ b/arch/powerpc/sysdev/mpic.c
@@ -354,6 +354,12 @@ static void mpic_startup_ht_interrupt(struct mpic *mpic, unsigned int source,
                 tmp |= 0x22;
         writel(tmp, fixup->base + 4);
         spin_unlock_irqrestore(&mpic->fixup_lock, flags);
+
+#ifdef CONFIG_PM
+        /* use the lowest bit inverted to the actual HW,
+         * set if this fixup was enabled, clear otherwise */
+        mpic->save_data[source].fixup_data = tmp | 1;
+#endif
 }
 
 static void mpic_shutdown_ht_interrupt(struct mpic *mpic, unsigned int source,
@@ -375,6 +381,12 @@ static void mpic_shutdown_ht_interrupt(struct mpic *mpic, unsigned int source,
         tmp |= 1;
         writel(tmp, fixup->base + 4);
         spin_unlock_irqrestore(&mpic->fixup_lock, flags);
+
+#ifdef CONFIG_PM
+        /* use the lowest bit inverted to the actual HW,
+         * set if this fixup was enabled, clear otherwise */
+        mpic->save_data[source].fixup_data = tmp & ~1;
+#endif
 }
 
 static void __init mpic_scan_ht_pic(struct mpic *mpic, u8 __iomem *devbase,
@@ -1143,7 +1155,7 @@ void __init mpic_init(struct mpic *mpic)
         /* Do the HT PIC fixups on U3 broken mpic */
         DBG("MPIC flags: %x\n", mpic->flags);
         if ((mpic->flags & MPIC_U3_HT_IRQS) && (mpic->flags & MPIC_PRIMARY))
-                mpic_scan_ht_pics(mpic);
+                mpic_scan_ht_pics(mpic);
 
         for (i = 0; i < mpic->num_sources; i++) {
                 /* start with vector = source number, and masked */
@@ -1167,6 +1179,12 @@ void __init mpic_init(struct mpic *mpic)
 
         /* Set current processor priority to 0 */
         mpic_cpu_write(MPIC_INFO(CPU_CURRENT_TASK_PRI), 0);
+
+#ifdef CONFIG_PM
+        /* allocate memory to save mpic state */
+        mpic->save_data = alloc_bootmem(mpic->num_sources * sizeof(struct mpic_irq_save));
+        BUG_ON(mpic->save_data == NULL);
+#endif
 }
 
 void __init mpic_set_clk_ratio(struct mpic *mpic, u32 clock_ratio)
@@ -1420,3 +1438,79 @@ void __devinit smp_mpic_setup_cpu(int cpu)
         mpic_setup_this_cpu();
 }
 #endif /* CONFIG_SMP */
+
+#ifdef CONFIG_PM
+static int mpic_suspend(struct sys_device *dev, pm_message_t state)
+{
+        struct mpic *mpic = container_of(dev, struct mpic, sysdev);
+        int i;
+
+        for (i = 0; i < mpic->num_sources; i++) {
+                mpic->save_data[i].vecprio =
+                        mpic_irq_read(i, MPIC_INFO(IRQ_VECTOR_PRI));
+                mpic->save_data[i].dest =
+                        mpic_irq_read(i, MPIC_INFO(IRQ_DESTINATION));
+        }
+
+        return 0;
+}
+
+static int mpic_resume(struct sys_device *dev)
+{
+        struct mpic *mpic = container_of(dev, struct mpic, sysdev);
+        int i;
+
+        for (i = 0; i < mpic->num_sources; i++) {
+                mpic_irq_write(i, MPIC_INFO(IRQ_VECTOR_PRI),
+                               mpic->save_data[i].vecprio);
+                mpic_irq_write(i, MPIC_INFO(IRQ_DESTINATION),
+                               mpic->save_data[i].dest);
+
+#ifdef CONFIG_MPIC_U3_HT_IRQS
+        {
+                struct mpic_irq_fixup *fixup = &mpic->fixups[i];
+
+                if (fixup->base) {
+                        /* we use the lowest bit in an inverted meaning */
+                        if ((mpic->save_data[i].fixup_data & 1) == 0)
+                                continue;
+
+                        /* Enable and configure */
+                        writeb(0x10 + 2 * fixup->index, fixup->base + 2);
+
+                        writel(mpic->save_data[i].fixup_data & ~1,
+                               fixup->base + 4);
+                }
+        }
+#endif
+        } /* end for loop */
+
+        return 0;
+}
+#endif
+
+static struct sysdev_class mpic_sysclass = {
+#ifdef CONFIG_PM
+        .resume = mpic_resume,
+        .suspend = mpic_suspend,
+#endif
+        set_kset_name("mpic"),
+};
+
+static int mpic_init_sys(void)
+{
+        struct mpic *mpic = mpics;
+        int error, id = 0;
+
+        error = sysdev_class_register(&mpic_sysclass);
+
+        while (mpic && !error) {
+                mpic->sysdev.cls = &mpic_sysclass;
+                mpic->sysdev.id = id++;
+                error = sysdev_register(&mpic->sysdev);
+                mpic = mpic->next;
+        }
+        return error;
+}
+
+device_initcall(mpic_init_sys);
diff --git a/include/asm-powerpc/mpic.h b/include/asm-powerpc/mpic.h
index e4d5fc5362a0..22c85c4f5b29 100644
--- a/include/asm-powerpc/mpic.h
+++ b/include/asm-powerpc/mpic.h
@@ -3,6 +3,7 @@
 #ifdef __KERNEL__
 
 #include <linux/irq.h>
+#include <linux/sysdev.h>
 #include <asm/dcr.h>
 
 /*
@@ -228,6 +229,14 @@ struct mpic_reg_bank {
 #endif /* CONFIG_PPC_DCR */
 };
 
+struct mpic_irq_save {
+        u32             vecprio,
+                        dest;
+#ifdef CONFIG_MPIC_U3_HT_IRQS
+        u32             fixup_data;
+#endif
+};
+
 /* The instance data of a given MPIC */
 struct mpic
 {
@@ -294,6 +303,12 @@ struct mpic
 
         /* link */
         struct mpic             *next;
+
+        struct sys_device       sysdev;
+
+#ifdef CONFIG_PM
+        struct mpic_irq_save    *save_data;
+#endif
 };
 
 /*