[PATCH 18/27] m68k/mac: Optimize interrupts using chain handlers

From: Geert Uytterhoeven
Date: Sun Oct 30 2011 - 08:50:28 EST


Signed-off-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
---
arch/m68k/mac/baboon.c | 38 +++++++++++++
arch/m68k/mac/oss.c | 106 +++++++++++++++++++++++++++++-------
arch/m68k/mac/psc.c | 74 +++++++++++++++++++------
arch/m68k/mac/via.c | 143 +++++++++++++++++++++++++++++++++++++++---------
4 files changed, 298 insertions(+), 63 deletions(-)

diff --git a/arch/m68k/mac/baboon.c b/arch/m68k/mac/baboon.c
index ff11746..425144c 100644
--- a/arch/m68k/mac/baboon.c
+++ b/arch/m68k/mac/baboon.c
@@ -56,6 +56,39 @@ void __init baboon_init(void)
* Baboon interrupt handler. This works a lot like a VIA.
*/

+#ifdef CONFIG_GENERIC_HARDIRQS
+static void baboon_irq(unsigned int irq, struct irq_desc *desc)
+{
+ int irq_bit, irq_num;
+ unsigned char events;
+
+#ifdef DEBUG_IRQS
+ printk("baboon_irq: mb_control %02X mb_ifr %02X mb_status %02X\n",
+ (uint) baboon->mb_control, (uint) baboon->mb_ifr,
+ (uint) baboon->mb_status);
+#endif
+
+ events = baboon->mb_ifr & 0x07;
+ if (!events)
+ return;
+
+ irq_num = IRQ_BABOON_0;
+ irq_bit = 1;
+ do {
+ if (events & irq_bit) {
+ baboon->mb_ifr &= ~irq_bit;
+ generic_handle_irq(irq_num);
+ }
+ irq_bit <<= 1;
+ irq_num++;
+ } while(events >= irq_bit);
+#if 0
+ if (baboon->mb_ifr & 0x02) macide_ack_intr(NULL);
+ /* for now we need to smash all interrupts */
+ baboon->mb_ifr &= ~events;
+#endif
+}
+#else
static irqreturn_t baboon_irq(int irq, void *dev_id)
{
int irq_bit, irq_num;
@@ -87,6 +120,7 @@ static irqreturn_t baboon_irq(int irq, void *dev_id)
#endif
return IRQ_HANDLED;
}
+#endif

/*
* Register the Baboon interrupt dispatcher on nubus slot $C.
@@ -95,8 +129,12 @@ static irqreturn_t baboon_irq(int irq, void *dev_id)
void __init baboon_register_interrupts(void)
{
baboon_disabled = 0;
+#ifdef CONFIG_GENERIC_HARDIRQS
+ irq_set_chained_handler(IRQ_NUBUS_C, baboon_irq);
+#else
if (request_irq(IRQ_NUBUS_C, baboon_irq, 0, "baboon", (void *)baboon))
pr_err("Couldn't register baboon interrupt\n");
+#endif
}

/*
diff --git a/arch/m68k/mac/oss.c b/arch/m68k/mac/oss.c
index ed95270..cc784c2 100644
--- a/arch/m68k/mac/oss.c
+++ b/arch/m68k/mac/oss.c
@@ -32,10 +32,11 @@
int oss_present;
volatile struct mac_oss *oss;

-static irqreturn_t oss_irq(int, void *);
-static irqreturn_t oss_nubus_irq(int, void *);
-
+#ifdef CONFIG_GENERIC_HARDIRQS
+extern void via1_irq(unsigned int irq, struct irq_desc *desc);
+#else
extern irqreturn_t via1_irq(int, void *);
+#endif

/*
* Initialize the OSS
@@ -63,23 +64,6 @@ void __init oss_init(void)
}

/*
- * Register the OSS and NuBus interrupt dispatchers.
- */
-
-void __init oss_register_interrupts(void)
-{
- if (request_irq(OSS_IRQLEV_SCSI, oss_irq, 0, "scsi", (void *)oss))
- pr_err("Couldn't register %s interrupt\n", "scsi");
- if (request_irq(OSS_IRQLEV_NUBUS, oss_nubus_irq, 0, "nubus",
- (void *)oss))
- pr_err("Couldn't register %s interrupt\n", "nubus");
- if (request_irq(OSS_IRQLEV_SOUND, oss_irq, 0, "sound", (void *)oss))
- pr_err("Couldn't register %s interrupt\n", "sound");
- if (request_irq(OSS_IRQLEV_VIA1, via1_irq, 0, "via1", (void *)via1))
- pr_err("Couldn't register %s interrupt\n", "via1");
-}
-
-/*
* Initialize OSS for Nubus access
*/

@@ -92,6 +76,34 @@ void __init oss_nubus_init(void)
* and SCSI; everything else is routed to its own autovector IRQ.
*/

+#ifdef CONFIG_GENERIC_HARDIRQS
+static void oss_irq(unsigned int irq, struct irq_desc *desc)
+{
+ int events;
+
+ events = oss->irq_pending & (OSS_IP_SOUND|OSS_IP_SCSI);
+ if (!events)
+ return;
+
+#ifdef DEBUG_IRQS
+ if ((console_loglevel == 10) && !(events & OSS_IP_SCSI)) {
+ printk("oss_irq: irq %u events = 0x%04X\n", irq,
+ (int) oss->irq_pending);
+ }
+#endif
+ /* FIXME: how do you clear a pending IRQ? */
+
+ if (events & OSS_IP_SOUND) {
+ oss->irq_pending &= ~OSS_IP_SOUND;
+ /* FIXME: call sound handler */
+ } else if (events & OSS_IP_SCSI) {
+ oss->irq_pending &= ~OSS_IP_SCSI;
+ generic_handle_irq(IRQ_MAC_SCSI);
+ } else {
+ /* FIXME: error check here? */
+ }
+}
+#else
static irqreturn_t oss_irq(int irq, void *dev_id)
{
int events;
@@ -119,6 +131,7 @@ static irqreturn_t oss_irq(int irq, void *dev_id)
}
return IRQ_HANDLED;
}
+#endif

/*
* Nubus IRQ handler, OSS style
@@ -126,6 +139,34 @@ static irqreturn_t oss_irq(int irq, void *dev_id)
* Unlike the VIA/RBV this is on its own autovector interrupt level.
*/

+#ifdef CONFIG_GENERIC_HARDIRQS
+static void oss_nubus_irq(unsigned int irq, struct irq_desc *desc)
+{
+ int events, irq_bit, i;
+
+ events = oss->irq_pending & OSS_IP_NUBUS;
+ if (!events)
+ return;
+
+#ifdef DEBUG_NUBUS_INT
+ if (console_loglevel > 7) {
+ printk("oss_nubus_irq: events = 0x%04X\n", events);
+ }
+#endif
+ /* There are only six slots on the OSS, not seven */
+
+ i = 6;
+ irq_bit = 0x40;
+ do {
+ --i;
+ irq_bit >>= 1;
+ if (events & irq_bit) {
+ oss->irq_pending &= ~irq_bit;
+ generic_handle_irq(NUBUS_SOURCE_BASE + i);
+ }
+ } while(events & (irq_bit - 1));
+}
+#else
static irqreturn_t oss_nubus_irq(int irq, void *dev_id)
{
int events, irq_bit, i;
@@ -153,6 +194,31 @@ static irqreturn_t oss_nubus_irq(int irq, void *dev_id)
} while(events & (irq_bit - 1));
return IRQ_HANDLED;
}
+#endif
+
+/*
+ * Register the OSS and NuBus interrupt dispatchers.
+ */
+
+void __init oss_register_interrupts(void)
+{
+#ifdef CONFIG_GENERIC_HARDIRQS
+ irq_set_chained_handler(OSS_IRQLEV_SCSI, oss_irq);
+ irq_set_chained_handler(OSS_IRQLEV_NUBUS, oss_nubus_irq);
+ irq_set_chained_handler(OSS_IRQLEV_SOUND, oss_irq);
+ irq_set_chained_handler(OSS_IRQLEV_VIA1, via1_irq);
+#else /* !CONFIG_GENERIC_HARDIRQS */
+ if (request_irq(OSS_IRQLEV_SCSI, oss_irq, 0, "scsi", (void *)oss))
+ pr_err("Couldn't register %s interrupt\n", "scsi");
+ if (request_irq(OSS_IRQLEV_NUBUS, oss_nubus_irq, 0, "nubus",
+ (void *)oss))
+ pr_err("Couldn't register %s interrupt\n", "nubus");
+ if (request_irq(OSS_IRQLEV_SOUND, oss_irq, 0, "sound", (void *)oss))
+ pr_err("Couldn't register %s interrupt\n", "sound");
+ if (request_irq(OSS_IRQLEV_VIA1, via1_irq, 0, "via1", (void *)via1))
+ pr_err("Couldn't register %s interrupt\n", "via1");
+#endif /* !CONFIG_GENERIC_HARDIRQS */
+}

/*
* Enable an OSS interrupt
diff --git a/arch/m68k/mac/psc.c b/arch/m68k/mac/psc.c
index 0a34b7a..52840b8 100644
--- a/arch/m68k/mac/psc.c
+++ b/arch/m68k/mac/psc.c
@@ -33,8 +33,6 @@
int psc_present;
volatile __u8 *psc;

-irqreturn_t psc_irq(int, void *);
-
/*
* Debugging dump, used in various places to see what's going on.
*/
@@ -115,26 +113,40 @@ void __init psc_init(void)
}

/*
- * Register the PSC interrupt dispatchers for autovector interrupts 3-6.
+ * PSC interrupt handler. It's a lot like the VIA interrupt handler.
*/

-void __init psc_register_interrupts(void)
+#ifdef CONFIG_GENERIC_HARDIRQS
+static void psc_irq(unsigned int irq, struct irq_desc *desc)
{
- if (request_irq(IRQ_AUTO_3, psc_irq, 0, "psc3", (void *) 0x30))
- pr_err("Couldn't register psc%d interrupt\n", 3);
- if (request_irq(IRQ_AUTO_4, psc_irq, 0, "psc4", (void *) 0x40))
- pr_err("Couldn't register psc%d interrupt\n", 4);
- if (request_irq(IRQ_AUTO_5, psc_irq, 0, "psc5", (void *) 0x50))
- pr_err("Couldn't register psc%d interrupt\n", 5);
- if (request_irq(IRQ_AUTO_6, psc_irq, 0, "psc6", (void *) 0x60))
- pr_err("Couldn't register psc%d interrupt\n", 6);
-}
+ unsigned int offset = (unsigned int)irq_desc_get_handler_data(desc);
+ int pIFR = pIFRbase + offset;
+ int pIER = pIERbase + offset;
+ int irq_num;
+ unsigned char irq_bit, events;

-/*
- * PSC interrupt handler. It's a lot like the VIA interrupt handler.
- */
+#ifdef DEBUG_IRQS
+ printk("psc_irq: irq %u pIFR = 0x%02X pIER = 0x%02X\n",
+ irq, (int) psc_read_byte(pIFR), (int) psc_read_byte(pIER));
+#endif

-irqreturn_t psc_irq(int irq, void *dev_id)
+ events = psc_read_byte(pIFR) & psc_read_byte(pIER) & 0xF;
+ if (!events)
+ return;
+
+ irq_num = irq << 3;
+ irq_bit = 1;
+ do {
+ if (events & irq_bit) {
+ psc_write_byte(pIFR, irq_bit);
+ generic_handle_irq(irq_num);
+ }
+ irq_num++;
+ irq_bit <<= 1;
+ } while (events >= irq_bit);
+}
+#else
+static irqreturn_t psc_irq(int irq, void *dev_id)
{
int pIFR = pIFRbase + ((int) dev_id);
int pIER = pIERbase + ((int) dev_id);
@@ -162,6 +174,34 @@ irqreturn_t psc_irq(int irq, void *dev_id)
} while (events >= irq_bit);
return IRQ_HANDLED;
}
+#endif
+
+/*
+ * Register the PSC interrupt dispatchers for autovector interrupts 3-6.
+ */
+
+void __init psc_register_interrupts(void)
+{
+#ifdef CONFIG_GENERIC_HARDIRQS
+ irq_set_chained_handler(IRQ_AUTO_3, psc_irq);
+ irq_set_handler_data(IRQ_AUTO_3, (void *)0x30);
+ irq_set_chained_handler(IRQ_AUTO_4, psc_irq);
+ irq_set_handler_data(IRQ_AUTO_4, (void *)0x40);
+ irq_set_chained_handler(IRQ_AUTO_5, psc_irq);
+ irq_set_handler_data(IRQ_AUTO_5, (void *)0x50);
+ irq_set_chained_handler(IRQ_AUTO_6, psc_irq);
+ irq_set_handler_data(IRQ_AUTO_6, (void *)0x60);
+#else /* !CONFIG_GENERIC_HARDIRQS */
+ if (request_irq(IRQ_AUTO_3, psc_irq, 0, "psc3", (void *) 0x30))
+ pr_err("Couldn't register psc%d interrupt\n", 3);
+ if (request_irq(IRQ_AUTO_4, psc_irq, 0, "psc4", (void *) 0x40))
+ pr_err("Couldn't register psc%d interrupt\n", 4);
+ if (request_irq(IRQ_AUTO_5, psc_irq, 0, "psc5", (void *) 0x50))
+ pr_err("Couldn't register psc%d interrupt\n", 5);
+ if (request_irq(IRQ_AUTO_6, psc_irq, 0, "psc6", (void *) 0x60))
+ pr_err("Couldn't register psc%d interrupt\n", 6);
+#endif /* !CONFIG_GENERIC_HARDIRQS */
+}

void psc_irq_enable(int irq) {
int irq_src = IRQ_SRC(irq);
diff --git a/arch/m68k/mac/via.c b/arch/m68k/mac/via.c
index bde156c..b8156ac 100644
--- a/arch/m68k/mac/via.c
+++ b/arch/m68k/mac/via.c
@@ -80,9 +80,6 @@ static int gIER,gIFR,gBufA,gBufB;
static u8 nubus_disabled;

void via_debug_dump(void);
-irqreturn_t via1_irq(int, void *);
-irqreturn_t via2_irq(int, void *);
-irqreturn_t via_nubus_irq(int, void *);
void via_irq_enable(int irq);
void via_irq_disable(int irq);
void via_irq_clear(int irq);
@@ -289,29 +286,6 @@ void __init via_init_clock(irq_handler_t func)
}

/*
- * Register the interrupt dispatchers for VIA or RBV machines only.
- */
-
-void __init via_register_interrupts(void)
-{
- if (via_alt_mapping) {
- if (request_irq(IRQ_AUTO_1, via1_irq, 0, "software",
- (void *)via1))
- pr_err("Couldn't register %s interrupt\n", "software");
- if (request_irq(IRQ_AUTO_6, via1_irq, 0, "via1", (void *)via1))
- pr_err("Couldn't register %s interrupt\n", "via1");
- } else {
- if (request_irq(IRQ_AUTO_1, via1_irq, 0, "via1", (void *)via1))
- pr_err("Couldn't register %s interrupt\n", "via1");
- }
- if (request_irq(IRQ_AUTO_2, via2_irq, 0, "via2", (void *)via2))
- pr_err("Couldn't register %s interrupt\n", "via2");
- if (request_irq(IRQ_MAC_NUBUS, via_nubus_irq, 0, "nubus",
- (void *)via2))
- pr_err("Couldn't register %s interrupt\n", "nubus");
-}
-
-/*
* Debugging dump, used in various places to see what's going on.
*/

@@ -443,6 +417,49 @@ void __init via_nubus_init(void)
* via6522.c :-), disable/pending masks added.
*/

+#ifdef CONFIG_GENERIC_HARDIRQS
+void via1_irq(unsigned int irq, struct irq_desc *desc)
+{
+ int irq_num;
+ unsigned char irq_bit, events;
+
+ events = via1[vIFR] & via1[vIER] & 0x7F;
+ if (!events)
+ return;
+
+ irq_num = VIA1_SOURCE_BASE;
+ irq_bit = 1;
+ do {
+ if (events & irq_bit) {
+ via1[vIFR] = irq_bit;
+ generic_handle_irq(irq_num);
+ }
+ ++irq_num;
+ irq_bit <<= 1;
+ } while (events >= irq_bit);
+}
+
+static void via2_irq(unsigned int irq, struct irq_desc *desc)
+{
+ int irq_num;
+ unsigned char irq_bit, events;
+
+ events = via2[gIFR] & via2[gIER] & 0x7F;
+ if (!events)
+ return;
+
+ irq_num = VIA2_SOURCE_BASE;
+ irq_bit = 1;
+ do {
+ if (events & irq_bit) {
+ via2[gIFR] = irq_bit | rbv_clear;
+ generic_handle_irq(irq_num);
+ }
+ ++irq_num;
+ irq_bit <<= 1;
+ } while (events >= irq_bit);
+}
+#else
irqreturn_t via1_irq(int irq, void *dev_id)
{
int irq_num;
@@ -486,12 +503,49 @@ irqreturn_t via2_irq(int irq, void *dev_id)
} while (events >= irq_bit);
return IRQ_HANDLED;
}
+#endif

/*
* Dispatch Nubus interrupts. We are called as a secondary dispatch by the
* VIA2 dispatcher as a fast interrupt handler.
*/

+#ifdef CONFIG_GENERIC_HARDIRQS
+void via_nubus_irq(unsigned int irq, struct irq_desc *desc)
+{
+ int slot_irq;
+ unsigned char slot_bit, events;
+
+ events = ~via2[gBufA] & 0x7F;
+ if (rbv_present)
+ events &= via2[rSIER];
+ else
+ events &= ~via2[vDirA];
+ if (!events)
+ return;
+
+ do {
+ slot_irq = IRQ_NUBUS_F;
+ slot_bit = 0x40;
+ do {
+ if (events & slot_bit) {
+ events &= ~slot_bit;
+ generic_handle_irq(slot_irq);
+ }
+ --slot_irq;
+ slot_bit >>= 1;
+ } while (events);
+
+ /* clear the CA1 interrupt and make certain there's no more. */
+ via2[gIFR] = 0x02 | rbv_clear;
+ events = ~via2[gBufA] & 0x7F;
+ if (rbv_present)
+ events &= via2[rSIER];
+ else
+ events &= ~via2[vDirA];
+ } while (events);
+}
+#else
irqreturn_t via_nubus_irq(int irq, void *dev_id)
{
int slot_irq;
@@ -527,6 +581,43 @@ irqreturn_t via_nubus_irq(int irq, void *dev_id)
} while (events);
return IRQ_HANDLED;
}
+#endif
+
+/*
+ * Register the interrupt dispatchers for VIA or RBV machines only.
+ */
+
+void __init via_register_interrupts(void)
+{
+#ifdef CONFIG_GENERIC_HARDIRQS
+ if (via_alt_mapping) {
+ /* software interrupt */
+ irq_set_chained_handler(IRQ_AUTO_1, via1_irq);
+ /* via1 interrupt */
+ irq_set_chained_handler(IRQ_AUTO_6, via1_irq);
+ } else {
+ irq_set_chained_handler(IRQ_AUTO_1, via1_irq);
+ }
+ irq_set_chained_handler(IRQ_AUTO_2, via2_irq);
+ irq_set_chained_handler(IRQ_MAC_NUBUS, via_nubus_irq);
+#else
+ if (via_alt_mapping) {
+ if (request_irq(IRQ_AUTO_1, via1_irq, 0, "software",
+ (void *)via1))
+ pr_err("Couldn't register %s interrupt\n", "software");
+ if (request_irq(IRQ_AUTO_6, via1_irq, 0, "via1", (void *)via1))
+ pr_err("Couldn't register %s interrupt\n", "via1");
+ } else {
+ if (request_irq(IRQ_AUTO_1, via1_irq, 0, "via1", (void *)via1))
+ pr_err("Couldn't register %s interrupt\n", "via1");
+ }
+ if (request_irq(IRQ_AUTO_2, via2_irq, 0, "via2", (void *)via2))
+ pr_err("Couldn't register %s interrupt\n", "via2");
+ if (request_irq(IRQ_MAC_NUBUS, via_nubus_irq, 0, "nubus",
+ (void *)via2))
+ pr_err("Couldn't register %s interrupt\n", "nubus");
+#endif
+}

void via_irq_enable(int irq) {
int irq_src = IRQ_SRC(irq);
--
1.7.0.4

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