1 files changed, 80 insertions, 61 deletions

diff --git a/arch/m68k/mac/via.c b/arch/m68k/mac/via.c
index 0c1cc45c570d..83a3bb0c0325 100644
--- a/arch/m68k/mac/via.c
+++ b/arch/m68k/mac/via.c
@@ -64,7 +64,19 @@ static int gIER,gIFR,gBufA,gBufB;
 #define MAC_CLOCK_LOW           (MAC_CLOCK_TICK&0xFF)
 #define MAC_CLOCK_HIGH          (MAC_CLOCK_TICK>>8)
 
-static int  nubus_active;
+/* To disable a NuBus slot on Quadras we make the slot IRQ lines outputs, set
+ * high. On RBV we just use the slot interrupt enable register. On Macs with
+ * genuine VIA chips we must use nubus_disabled to keep track of disabled slot
+ * interrupts. When any slot IRQ is disabled we mask the (edge triggered) CA1
+ * or "SLOTS" interrupt. When no slot is disabled, we unmask the CA1 interrupt.
+ * So, on genuine VIAs, having more than one NuBus IRQ can mean trouble,
+ * because closing one of those drivers can mask all of the NuBus interrupts.
+ * Also, since we can't mask the unregistered slot IRQs on genuine VIAs, it's
+ * possible to get interrupts from cards that MacOS or the ROM has configured
+ * but we have not. FWIW, "Designing Cards and Drivers for Macintosh II and
+ * Macintosh SE", page 9-8, says, a slot IRQ with no driver would crash MacOS.
+ */
+static u8 nubus_disabled;
 
 void via_debug_dump(void);
 irqreturn_t via1_irq(int, void *);
@@ -383,9 +395,6 @@ int via_get_cache_disable(void)
 
 void __init via_nubus_init(void)
 {
-        /* don't set nubus_active = 0 here, it kills the Baboon */
-        /* interrupt that we've already registered.             */
-
         /* unlock nubus transactions */
 
         if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
@@ -399,28 +408,35 @@ void __init via_nubus_init(void)
                 via2[gBufB] |= 0x02;
         }
 
-        /* disable nubus slot interrupts. */
-        if (rbv_present) {
+        /* Disable all the slot interrupts (where possible). */
+
+        switch (macintosh_config->via_type) {
+        case MAC_VIA_II:
+                /* Just make the port A lines inputs. */
+                switch(macintosh_config->ident) {
+                case MAC_MODEL_II:
+                case MAC_MODEL_IIX:
+                case MAC_MODEL_IICX:
+                case MAC_MODEL_SE30:
+                        /* The top two bits are RAM size outputs. */
+                        via2[vDirA] &= 0xC0;
+                        break;
+                default:
+                        via2[vDirA] &= 0x80;
+                }
+                break;
+        case MAC_VIA_IIci:
+                /* RBV. Disable all the slot interrupts. SIER works like IER. */
                 via2[rSIER] = 0x7F;
-                via2[rSIER] = nubus_active | 0x80;
-        } else {
-                /* These are ADB bits on PMU */
+                break;
+        case MAC_VIA_QUADRA:
+                /* Disable the inactive slot interrupts by making those lines outputs. */
                 if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
-                   (macintosh_config->adb_type != MAC_ADB_PB2)) {
-                        switch(macintosh_config->ident)
-                        {
-                                case MAC_MODEL_II:
-                                case MAC_MODEL_IIX:
-                                case MAC_MODEL_IICX:
-                                case MAC_MODEL_SE30:
-                                        via2[vBufA] |= 0x3F;
-                                        via2[vDirA] = ~nubus_active | 0xc0;
-                                        break;
-                                default:
-                                        via2[vBufA] = 0xFF;
-                                        via2[vDirA] = ~nubus_active;
-                        }
+                    (macintosh_config->adb_type != MAC_ADB_PB2)) {
+                        via2[vBufA] |= 0x7F;
+                        via2[vDirA] |= 0x7F;
                 }
+                break;
         }
 }
 
@@ -489,7 +505,8 @@ irqreturn_t via2_irq(int irq, void *dev_id)
                         via2[gIER] = irq_bit;
                         via2[gIFR] = irq_bit | rbv_clear;
                         m68k_handle_int(irq_num);
-                        via2[gIER] = irq_bit | 0x80;
+                        if (irq_num != IRQ_MAC_NUBUS || nubus_disabled == 0)
+                                via2[gIER] = irq_bit | 0x80;
                 }
                 ++irq_num;
                 irq_bit <<= 1;
@@ -511,7 +528,7 @@ irqreturn_t via_nubus_irq(int irq, void *dev_id)
         if (rbv_present)
                 events &= via2[rSIER];
         else
-                events &= nubus_active;
+                events &= ~via2[vDirA];
         if (!events)
                 return IRQ_NONE;
 
@@ -533,7 +550,7 @@ irqreturn_t via_nubus_irq(int irq, void *dev_id)
                 if (rbv_present)
                         events &= via2[rSIER];
                 else
-                        events &= nubus_active;
+                        events &= ~via2[vDirA];
         } while (events);
         return IRQ_HANDLED;
 }
@@ -541,38 +558,38 @@ irqreturn_t via_nubus_irq(int irq, void *dev_id)
 void via_irq_enable(int irq) {
         int irq_src     = IRQ_SRC(irq);
         int irq_idx     = IRQ_IDX(irq);
-        int irq_bit     = 1 << irq_idx;
 
 #ifdef DEBUG_IRQUSE
         printk(KERN_DEBUG "via_irq_enable(%d)\n", irq);
 #endif
 
         if (irq_src == 1) {
-                via1[vIER] = irq_bit | 0x80;
+                via1[vIER] = IER_SET_BIT(irq_idx);
         } else if (irq_src == 2) {
-                via2[gIER] = irq_bit | 0x80;
+                if (irq != IRQ_MAC_NUBUS || nubus_disabled == 0)
+                        via2[gIER] = IER_SET_BIT(irq_idx);
         } else if (irq_src == 7) {
-                nubus_active |= irq_bit;
-                if (rbv_present) {
-                        /* enable the slot interrupt. SIER works like IER. */
+                switch (macintosh_config->via_type) {
+                case MAC_VIA_II:
+                        nubus_disabled &= ~(1 << irq_idx);
+                        /* Enable the CA1 interrupt when no slot is disabled. */
+                        if (!nubus_disabled)
+                                via2[gIER] = IER_SET_BIT(1);
+                        break;
+                case MAC_VIA_IIci:
+                        /* On RBV, enable the slot interrupt.
+                         * SIER works like IER.
+                         */
                         via2[rSIER] = IER_SET_BIT(irq_idx);
-                } else {
-                        /* Make sure the bit is an input, to enable the irq */
-                        /* But not on PowerBooks, that's ADB... */
+                        break;
+                case MAC_VIA_QUADRA:
+                        /* Make the port A line an input to enable the slot irq.
+                         * But not on PowerBooks, that's ADB.
+                         */
                         if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
-                           (macintosh_config->adb_type != MAC_ADB_PB2)) {
-                                switch(macintosh_config->ident)
-                                {
-                                        case MAC_MODEL_II:
-                                        case MAC_MODEL_IIX:
-                                        case MAC_MODEL_IICX:
-                                        case MAC_MODEL_SE30:
-                                                via2[vDirA] &= (~irq_bit | 0xc0);
-                                                break;
-                                        default:
-                                                via2[vDirA] &= ~irq_bit;
-                                }
-                        }
+                            (macintosh_config->adb_type != MAC_ADB_PB2))
+                                via2[vDirA] &= ~(1 << irq_idx);
+                        break;
                 }
         }
 }
@@ -580,29 +597,31 @@ void via_irq_enable(int irq) {
 void via_irq_disable(int irq) {
         int irq_src     = IRQ_SRC(irq);
         int irq_idx     = IRQ_IDX(irq);
-        int irq_bit     = 1 << irq_idx;
 
 #ifdef DEBUG_IRQUSE
         printk(KERN_DEBUG "via_irq_disable(%d)\n", irq);
 #endif
 
         if (irq_src == 1) {
-                via1[vIER] = irq_bit & 0x7F;
+                via1[vIER] = IER_CLR_BIT(irq_idx);
         } else if (irq_src == 2) {
-                via2[gIER] = irq_bit & 0x7F;
+                via2[gIER] = IER_CLR_BIT(irq_idx);
         } else if (irq_src == 7) {
-                if (rbv_present) {
-                        /* disable the slot interrupt.  SIER works like IER. */
+                switch (macintosh_config->via_type) {
+                case MAC_VIA_II:
+                        nubus_disabled |= 1 << irq_idx;
+                        if (nubus_disabled)
+                                via2[gIER] = IER_CLR_BIT(1);
+                        break;
+                case MAC_VIA_IIci:
                         via2[rSIER] = IER_CLR_BIT(irq_idx);
-                } else {
-                        /* disable the nubus irq by changing dir to output */
-                        /* except on PMU */
+                        break;
+                case MAC_VIA_QUADRA:
                         if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
-                           (macintosh_config->adb_type != MAC_ADB_PB2)) {
-                                via2[vDirA] |= irq_bit;
-                        }
+                            (macintosh_config->adb_type != MAC_ADB_PB2))
+                                via2[vDirA] |= 1 << irq_idx;
+                        break;
                 }
-                nubus_active &= ~irq_bit;
         }
 }
 
@@ -638,7 +657,7 @@ int via_irq_pending(int irq)
         } else if (irq_src == 2) {
                 return via2[gIFR] & irq_bit;
         } else if (irq_src == 7) {
-                /* FIXME: this can't work while a slot irq is disabled! */
+                /* Always 0 for MAC_VIA_QUADRA if the slot irq is disabled. */
                 return ~via2[gBufA] & irq_bit;
         }
         return 0;