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-rw-r--r--debian/patches/bugfix/m68k/mac68k-irq-plan-e.diff270
1 files changed, 270 insertions, 0 deletions
diff --git a/debian/patches/bugfix/m68k/mac68k-irq-plan-e.diff b/debian/patches/bugfix/m68k/mac68k-irq-plan-e.diff
new file mode 100644
index 000000000000..fb367101d197
--- /dev/null
+++ b/debian/patches/bugfix/m68k/mac68k-irq-plan-e.diff
@@ -0,0 +1,270 @@
+Subject: [PATCH 7/13] m68k: Mac nubus IRQ fixes (plan E)
+
+From: Finn Thain <fthain@telegraphics.com.au>
+
+Some Macs lack a slot interrupt enable register. So the existing code makes
+disabled and unregistered slot IRQ lines outputs set high. This seems to work
+on quadras, but does not work on genuine VIAs (perhaps the card still succeeds
+in pulling the line low, or perhaps because this increases the settle time on
+the port A input, meaning that the CA1 IRQ could fire before the slot line
+reads active).
+
+Because of this, the nubus_active flags were used to mask IRQs, which is
+actually worse than the problem it tries to solve. Any interrupt masked by
+nubus_active will remain asserted and prevent further transitions on CA1. And
+so the nubus gets wedged regardless of hardware (emulated VIA ASIC, real VIA
+chip or RBV).
+
+The best solution to this hardware limitation of genuine VIAs is to disable the
+umbrella SLOTS IRQ when disabling a slot on those machines. Unfortunately, this
+means all slot IRQs get disabled when any slot IRQ is disabled. But it is only
+a problem when there's more than 1 device using nubus interrupts.
+
+Another potential problem for genuine VIAs is an unregistered nubus IRQ.
+Eventually it will be possible to enable the CA1 interrupt by installing its
+handler only _after_ all nubus drivers have loaded but _before_ the kernel
+needs them, at which time this last problem can be fixed. For now it can be
+worked around:
+
+ - disable MacOS extensions
+ - don't boot MacOS (use the Emile bootloader instead)
+ - get the bootloaders to disable ROM drivers (Penguin does this for video
+ cards already, don't know about Emile)
+ - physically remove unsupported cards
+
+Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
+Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
+---
+ arch/m68k/mac/via.c | 141 +++++++++++++++++++++++++++++-----------------------
+ 1 file changed, 80 insertions(+), 61 deletions(-)
+
+--- linux-m68k-2.6.21.orig/arch/m68k/mac/via.c
++++ linux-m68k-2.6.21/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_
+ 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
+ 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
+ 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
+ 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;
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