[PATCH] ARM: Orion: Hoist bridge interrupt handling out of the timer

From: Jason Gunthorpe
Date: Fri Dec 07 2012 - 17:55:03 EST

The intent of this patch is to expose the other bridge cause
interrupts to users in the kernel.

- Add orion_bridge_irq_init to create a new edge triggered interrupt
chip based on the bridge cause register
- Remove all interrupt register code from time.c and use normal
interrupt functions instead
- Update the machines that use orion_time_init to call
orion_bridge_irq_init and use the new signature

Tested on a Kirkwood platform.

NOTE: I'm skeptical that MV78xx0 has a bridge interrupt cause/mask
register. However, it was setup so the timer code would touch those
registers, so I've preserved that. Unfortunately prior to this patch
the 'bridge cause register' was only written to, never read. If it is
wired-to-zero on MV78xx0 because it doesn't exist then the timer will
fail to function. The fix is easy, but I need someone with the
manual/system to tell me which is right.

Signed-off-by: Jason Gunthorpe <jgunthorpe@xxxxxxxxxxxxxxxxxxxx>
---
arch/arm/mach-dove/common.c | 5 +-
arch/arm/mach-dove/include/mach/bridge-regs.h | 2 +-
arch/arm/mach-dove/include/mach/irqs.h | 9 +++-
arch/arm/mach-kirkwood/common.c | 6 ++-
arch/arm/mach-kirkwood/include/mach/bridge-regs.h | 2 -
arch/arm/mach-kirkwood/include/mach/irqs.h | 14 +++++-
arch/arm/mach-mv78xx0/common.c | 8 +++-
arch/arm/mach-mv78xx0/include/mach/bridge-regs.h | 2 +-
arch/arm/mach-mv78xx0/include/mach/irqs.h | 9 +++-
arch/arm/mach-orion5x/common.c | 6 ++-
arch/arm/mach-orion5x/include/mach/bridge-regs.h | 2 -
arch/arm/mach-orion5x/include/mach/irqs.h | 9 +++-
arch/arm/plat-orion/include/plat/irq.h | 3 +
arch/arm/plat-orion/include/plat/time.h | 4 +-
arch/arm/plat-orion/irq.c | 51 +++++++++++++++++++++
arch/arm/plat-orion/time.c | 46 ++++---------------
16 files changed, 120 insertions(+), 58 deletions(-)

My immediate need is to have the kernel panic on watchdog timer
expiry, but I also think this might be the first step to clean up this
item:

/*
* Disable propagation of mbus errors to the CPU local bus,
* as this causes mbus errors (which can occur for example
* for PCI aborts) to throw CPU aborts, which we're not set
* up to deal with.
*/
writel(readl(CPU_CONFIG) & ~CPU_CONFIG_ERROR_PROP, CPU_CONFIG);

Regards,
Jason

diff --git a/arch/arm/mach-dove/common.c b/arch/arm/mach-dove/common.c
index f723fe1..9107808 100644
--- a/arch/arm/mach-dove/common.c
+++ b/arch/arm/mach-dove/common.c
@@ -243,8 +243,9 @@ static int __init dove_find_tclk(void)
static void __init dove_timer_init(void)
{
dove_tclk = dove_find_tclk();
- orion_time_init(BRIDGE_VIRT_BASE, BRIDGE_INT_TIMER1_CLR,
- IRQ_DOVE_BRIDGE, dove_tclk);
+ orion_bridge_irq_init(IRQ_DOVE_BRIDGE, IRQ_DOVE_BRIDGE_START,
+ BRIDGE_CAUSE);
+ orion_time_init(IRQ_DOVE_BRIDGE_TIMER1, dove_tclk);
}

struct sys_timer dove_timer = {
diff --git a/arch/arm/mach-dove/include/mach/bridge-regs.h b/arch/arm/mach-dove/include/mach/bridge-regs.h
index 99f259e..3bd4656 100644
--- a/arch/arm/mach-dove/include/mach/bridge-regs.h
+++ b/arch/arm/mach-dove/include/mach/bridge-regs.h
@@ -26,7 +26,7 @@
#define SYSTEM_SOFT_RESET (BRIDGE_VIRT_BASE + 0x010c)
#define SOFT_RESET 0x00000001

-#define BRIDGE_INT_TIMER1_CLR (~0x0004)
+#define BRIDGE_CAUSE (BRIDGE_VIRT_BASE + 0x0110)

#define IRQ_VIRT_BASE (BRIDGE_VIRT_BASE + 0x0200)
#define IRQ_CAUSE_LOW_OFF 0x0000
diff --git a/arch/arm/mach-dove/include/mach/irqs.h b/arch/arm/mach-dove/include/mach/irqs.h
index 03d401d..53c7d82 100644
--- a/arch/arm/mach-dove/include/mach/irqs.h
+++ b/arch/arm/mach-dove/include/mach/irqs.h
@@ -78,9 +78,16 @@
#define IRQ_DOVE_SATA 62

/*
+ * Bridge Interrupt Controller
+ */
+#define IRQ_DOVE_BRIDGE_START 64
+#define IRQ_DOVE_BRIDGE_TIMER1 (IRQ_DOVE_BRIDGE_START + 2)
+#define NR_BRIDGE_IRQS 6
+
+/*
* DOVE General Purpose Pins
*/
-#define IRQ_DOVE_GPIO_START 64
+#define IRQ_DOVE_GPIO_START (IRQ_DOVE_BRIDGE_START + NR_BRIDGE_IRQS)
#define NR_GPIO_IRQS 64

/*
diff --git a/arch/arm/mach-kirkwood/common.c b/arch/arm/mach-kirkwood/common.c
index 906c22e..6ec60b8 100644
--- a/arch/arm/mach-kirkwood/common.c
+++ b/arch/arm/mach-kirkwood/common.c
@@ -35,6 +35,7 @@
#include <plat/time.h>
#include <plat/addr-map.h>
#include <linux/platform_data/dma-mv_xor.h>
+#include <plat/irq.h>
#include "common.h"

/*****************************************************************************
@@ -534,8 +535,9 @@ static void __init kirkwood_timer_init(void)
{
kirkwood_tclk = kirkwood_find_tclk();

- orion_time_init(BRIDGE_VIRT_BASE, BRIDGE_INT_TIMER1_CLR,
- IRQ_KIRKWOOD_BRIDGE, kirkwood_tclk);
+ orion_bridge_irq_init(IRQ_KIRKWOOD_BRIDGE, IRQ_KIRKWOOD_BRIDGE_START,
+ BRIDGE_CAUSE);
+ orion_time_init(IRQ_KIRKWOOD_BRIDGE_TIMER1, kirkwood_tclk);
}

struct sys_timer kirkwood_timer = {
diff --git a/arch/arm/mach-kirkwood/include/mach/bridge-regs.h b/arch/arm/mach-kirkwood/include/mach/bridge-regs.h
index 5c82b7d..fd66a56 100644
--- a/arch/arm/mach-kirkwood/include/mach/bridge-regs.h
+++ b/arch/arm/mach-kirkwood/include/mach/bridge-regs.h
@@ -29,8 +29,6 @@
#define BRIDGE_CAUSE (BRIDGE_VIRT_BASE + 0x0110)
#define WDT_INT_REQ 0x0008

-#define BRIDGE_INT_TIMER1_CLR (~0x0004)
-
#define IRQ_VIRT_BASE (BRIDGE_VIRT_BASE + 0x0200)
#define IRQ_CAUSE_LOW_OFF 0x0000
#define IRQ_MASK_LOW_OFF 0x0004
diff --git a/arch/arm/mach-kirkwood/include/mach/irqs.h b/arch/arm/mach-kirkwood/include/mach/irqs.h
index 2bf8161..9e6f406 100644
--- a/arch/arm/mach-kirkwood/include/mach/irqs.h
+++ b/arch/arm/mach-kirkwood/include/mach/irqs.h
@@ -54,9 +54,21 @@
#define IRQ_KIRKWOOD_RTC 53

/*
+ * Bridge Interrupt Controller
+ */
+#define IRQ_KIRKWOOD_BRIDGE_START 64
+#define IRQ_KIRKWOOD_BRIDGE_SELFINT (IRQ_KIRKWOOD_BRIDGE_START + 0)
+#define IRQ_KIRKWOOD_BRIDGE_TIMER0 (IRQ_KIRKWOOD_BRIDGE_START + 1)
+#define IRQ_KIRKWOOD_BRIDGE_TIMER1 (IRQ_KIRKWOOD_BRIDGE_START + 2)
+#define IRQ_KIRKWOOD_BRIDGE_TIMERWD (IRQ_KIRKWOOD_BRIDGE_START + 3)
+#define IRQ_KIRKWOOD_BRIDGE_ACCESSERR (IRQ_KIRKWOOD_BRIDGE_START + 4)
+#define IRQ_KIRKWOOD_BRIDGE_BIT64ERR (IRQ_KIRKWOOD_BRIDGE_START + 5)
+#define NR_BRIDGE_IRQS 6
+
+/*
* KIRKWOOD General Purpose Pins
*/
-#define IRQ_KIRKWOOD_GPIO_START 64
+#define IRQ_KIRKWOOD_GPIO_START (IRQ_KIRKWOOD_BRIDGE_START + NR_BRIDGE_IRQS)
#define NR_GPIO_IRQS 50

#define NR_IRQS (IRQ_KIRKWOOD_GPIO_START + NR_GPIO_IRQS)
diff --git a/arch/arm/mach-mv78xx0/common.c b/arch/arm/mach-mv78xx0/common.c
index d0cb485..34bdf2a 100644
--- a/arch/arm/mach-mv78xx0/common.c
+++ b/arch/arm/mach-mv78xx0/common.c
@@ -25,6 +25,7 @@
#include <plat/time.h>
#include <plat/common.h>
#include <plat/addr-map.h>
+#include <plat/irq.h>
#include "common.h"

static int get_tclk(void);
@@ -338,8 +339,11 @@ void __init mv78xx0_init_early(void)

static void __init_refok mv78xx0_timer_init(void)
{
- orion_time_init(BRIDGE_VIRT_BASE, BRIDGE_INT_TIMER1_CLR,
- IRQ_MV78XX0_TIMER_1, get_tclk());
+ /* FIXME: MV78XX0 may not have a bridge cause register, in which case
+ * the timer should run directly from IRQ_MV78XX0_TIMER_1 */
+ orion_bridge_irq_init(IRQ_MV78XX0_TIMER_1, IRQ_MV78XX0_BRIDGE_START,
+ BRIDGE_CAUSE);
+ orion_time_init(IRQ_MV78XX0_BRIDGE_TIMER1, get_tclk());
}

struct sys_timer mv78xx0_timer = {
diff --git a/arch/arm/mach-mv78xx0/include/mach/bridge-regs.h b/arch/arm/mach-mv78xx0/include/mach/bridge-regs.h
index 5f03484..787bd2a 100644
--- a/arch/arm/mach-mv78xx0/include/mach/bridge-regs.h
+++ b/arch/arm/mach-mv78xx0/include/mach/bridge-regs.h
@@ -20,7 +20,7 @@
#define SYSTEM_SOFT_RESET (BRIDGE_VIRT_BASE + 0x010c)
#define SOFT_RESET 0x00000001

-#define BRIDGE_INT_TIMER1_CLR (~0x0004)
+#define BRIDGE_CAUSE (BRIDGE_VIRT_BASE + 0x0110)

#define IRQ_VIRT_BASE (BRIDGE_VIRT_BASE + 0x0200)
#define IRQ_CAUSE_ERR_OFF 0x0000
diff --git a/arch/arm/mach-mv78xx0/include/mach/irqs.h b/arch/arm/mach-mv78xx0/include/mach/irqs.h
index fa1d422..f5ebebc 100644
--- a/arch/arm/mach-mv78xx0/include/mach/irqs.h
+++ b/arch/arm/mach-mv78xx0/include/mach/irqs.h
@@ -83,9 +83,16 @@
#define IRQ_MV78XX0_GE_ERR 70

/*
+ * Bridge Interrupt Controller
+ */
+#define IRQ_MV78XX0_BRIDGE_START 96
+#define IRQ_MV78XX0_BRIDGE_TIMER1 (IRQ_MV78XX0_BRIDGE_START + 2)
+#define NR_BRIDGE_IRQS 6
+
+/*
* MV78XX0 General Purpose Pins
*/
-#define IRQ_MV78XX0_GPIO_START 96
+#define IRQ_MV78XX0_GPIO_START (IRQ_MV78XX0_BRIDGE_START + NR_BRIDGE_IRQS)
#define NR_GPIO_IRQS 32

#define NR_IRQS (IRQ_MV78XX0_GPIO_START + NR_GPIO_IRQS)
diff --git a/arch/arm/mach-orion5x/common.c b/arch/arm/mach-orion5x/common.c
index b3eb3da..1d8c281 100644
--- a/arch/arm/mach-orion5x/common.c
+++ b/arch/arm/mach-orion5x/common.c
@@ -35,6 +35,7 @@
#include <plat/time.h>
#include <plat/common.h>
#include <plat/addr-map.h>
+#include <plat/irq.h>
#include "common.h"

/*****************************************************************************
@@ -221,8 +222,9 @@ static void __init orion5x_timer_init(void)
{
orion5x_tclk = orion5x_find_tclk();

- orion_time_init(ORION5X_BRIDGE_VIRT_BASE, BRIDGE_INT_TIMER1_CLR,
- IRQ_ORION5X_BRIDGE, orion5x_tclk);
+ orion_bridge_irq_init(IRQ_ORION5X_BRIDGE, IRQ_ORION5X_BRIDGE_START,
+ BRIDGE_CAUSE);
+ orion_time_init(IRQ_ORION5X_BRIDGE_TIMER1, orion5x_tclk);
}

struct sys_timer orion5x_timer = {
diff --git a/arch/arm/mach-orion5x/include/mach/bridge-regs.h b/arch/arm/mach-orion5x/include/mach/bridge-regs.h
index 461fd69..0847182 100644
--- a/arch/arm/mach-orion5x/include/mach/bridge-regs.h
+++ b/arch/arm/mach-orion5x/include/mach/bridge-regs.h
@@ -28,8 +28,6 @@

#define WDT_INT_REQ 0x0008

-#define BRIDGE_INT_TIMER1_CLR (~0x0004)
-
#define MAIN_IRQ_CAUSE (ORION5X_BRIDGE_VIRT_BASE + 0x200)

#define MAIN_IRQ_MASK (ORION5X_BRIDGE_VIRT_BASE + 0x204)
diff --git a/arch/arm/mach-orion5x/include/mach/irqs.h b/arch/arm/mach-orion5x/include/mach/irqs.h
index a6fa9d8..329cdc2 100644
--- a/arch/arm/mach-orion5x/include/mach/irqs.h
+++ b/arch/arm/mach-orion5x/include/mach/irqs.h
@@ -49,9 +49,16 @@
#define IRQ_ORION5X_XOR1 31

/*
+ * Bridge Interrupt Controller
+ */
+#define IRQ_ORION5X_BRIDGE_START 32
+#define IRQ_ORION5X_BRIDGE_TIMER1 (IRQ_ORION5X_BRIDGE_START + 2)
+#define NR_BRIDGE_IRQS 6
+
+/*
* Orion General Purpose Pins
*/
-#define IRQ_ORION5X_GPIO_START 32
+#define IRQ_ORION5X_GPIO_START (IRQ_ORION5X_BRIDGE_START + NR_BRIDGE_IRQS)
#define NR_GPIO_IRQS 32

#define NR_IRQS (IRQ_ORION5X_GPIO_START + NR_GPIO_IRQS)
diff --git a/arch/arm/plat-orion/include/plat/irq.h b/arch/arm/plat-orion/include/plat/irq.h
index 50547e4..10d1f44 100644
--- a/arch/arm/plat-orion/include/plat/irq.h
+++ b/arch/arm/plat-orion/include/plat/irq.h
@@ -12,5 +12,8 @@
#define __PLAT_IRQ_H

void orion_irq_init(unsigned int irq_start, void __iomem *maskaddr);
+void __init orion_bridge_irq_init(unsigned int bridge_irq,
+ unsigned int irq_start,
+ void __iomem *causeaddr);
void __init orion_dt_init_irq(void);
#endif
diff --git a/arch/arm/plat-orion/include/plat/time.h b/arch/arm/plat-orion/include/plat/time.h
index 07527e4..c5ccc0a 100644
--- a/arch/arm/plat-orion/include/plat/time.h
+++ b/arch/arm/plat-orion/include/plat/time.h
@@ -13,8 +13,6 @@

void orion_time_set_base(void __iomem *timer_base);

-void orion_time_init(void __iomem *bridge_base, u32 bridge_timer1_clr_mask,
- unsigned int irq, unsigned int tclk);
-
+void orion_time_init(unsigned int irq, unsigned int tclk);

#endif
diff --git a/arch/arm/plat-orion/irq.c b/arch/arm/plat-orion/irq.c
index 1867944..3455686 100644
--- a/arch/arm/plat-orion/irq.c
+++ b/arch/arm/plat-orion/irq.c
@@ -18,6 +18,57 @@
#include <plat/irq.h>
#include <plat/orion-gpio.h>

+static void bridge_irq_handler(unsigned irq, struct irq_desc *desc)
+{
+ struct irq_chip_generic *gc = irq_get_handler_data(irq);
+ u32 cause;
+ int i;
+
+ cause = readl(gc->reg_base) & readl(gc->reg_base + 4);
+ for (i = 0; i < 6; i++)
+ if ((cause & (1 << i)))
+ generic_handle_irq(i + gc->irq_base);
+}
+
+static void irq_gc_eoi_inv(struct irq_data *d)
+{
+ struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+ u32 mask = 1 << (d->irq - gc->irq_base);
+ struct irq_chip_regs *regs;
+
+ regs = &container_of(d->chip, struct irq_chip_type, chip)->regs;
+ irq_gc_lock(gc);
+ irq_reg_writel(~mask, gc->reg_base + regs->eoi);
+ irq_gc_unlock(gc);
+}
+
+void __init orion_bridge_irq_init(unsigned int bridge_irq,
+ unsigned int irq_start,
+ void __iomem *causeaddr)
+{
+ struct irq_chip_generic *gc;
+ struct irq_chip_type *ct;
+
+ gc = irq_alloc_generic_chip("orion_irq_edge", 1, irq_start,
+ causeaddr, handle_fasteoi_irq);
+ if (!gc)
+ BUG();
+ ct = gc->chip_types;
+ ct->regs.mask = 4;
+ ct->regs.eoi = 0;
+ /* ACK and mask all interrupts */
+ writel(0, causeaddr);
+ writel(0, causeaddr + ct->regs.mask);
+ ct->chip.irq_eoi = irq_gc_eoi_inv;
+ ct->chip.irq_mask = irq_gc_mask_clr_bit;
+ ct->chip.irq_unmask = irq_gc_mask_set_bit;
+ irq_setup_generic_chip(gc, IRQ_MSK(6), IRQ_GC_INIT_MASK_CACHE,
+ IRQ_NOREQUEST, IRQ_LEVEL | IRQ_NOPROBE);
+ if (irq_set_handler_data(bridge_irq, gc) != 0)
+ BUG();
+ irq_set_chained_handler(bridge_irq, bridge_irq_handler);
+}
+
void __init orion_irq_init(unsigned int irq_start, void __iomem *maskaddr)
{
struct irq_chip_generic *gc;
diff --git a/arch/arm/plat-orion/time.c b/arch/arm/plat-orion/time.c
index 0f4fa86..da22aa4 100644
--- a/arch/arm/plat-orion/time.c
+++ b/arch/arm/plat-orion/time.c
@@ -17,15 +17,8 @@
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <asm/sched_clock.h>
-
-/*
- * MBus bridge block registers.
- */
-#define BRIDGE_CAUSE_OFF 0x0110
-#define BRIDGE_MASK_OFF 0x0114
-#define BRIDGE_INT_TIMER0 0x0002
-#define BRIDGE_INT_TIMER1 0x0004
-
+#include <linux/sched.h>
+#include <plat/time.h>

/*
* Timer block registers.
@@ -44,9 +37,8 @@
/*
* SoC-specific data.
*/
-static void __iomem *bridge_base;
-static u32 bridge_timer1_clr_mask;
static void __iomem *timer_base;
+static unsigned int timer_irq;


/*
@@ -82,11 +74,7 @@ orion_clkevt_next_event(unsigned long delta, struct clock_event_device *dev)
/*
* Clear and enable clockevent timer interrupt.
*/
- writel(bridge_timer1_clr_mask, bridge_base + BRIDGE_CAUSE_OFF);
-
- u = readl(bridge_base + BRIDGE_MASK_OFF);
- u |= BRIDGE_INT_TIMER1;
- writel(u, bridge_base + BRIDGE_MASK_OFF);
+ enable_irq(timer_irq);

/*
* Setup new clockevent timer value.
@@ -122,8 +110,7 @@ orion_clkevt_mode(enum clock_event_mode mode, struct clock_event_device *dev)
/*
* Enable timer interrupt.
*/
- u = readl(bridge_base + BRIDGE_MASK_OFF);
- writel(u | BRIDGE_INT_TIMER1, bridge_base + BRIDGE_MASK_OFF);
+ enable_irq(timer_irq);

/*
* Enable timer.
@@ -141,14 +128,7 @@ orion_clkevt_mode(enum clock_event_mode mode, struct clock_event_device *dev)
/*
* Disable timer interrupt.
*/
- u = readl(bridge_base + BRIDGE_MASK_OFF);
- writel(u & ~BRIDGE_INT_TIMER1, bridge_base + BRIDGE_MASK_OFF);
-
- /*
- * ACK pending timer interrupt.
- */
- writel(bridge_timer1_clr_mask, bridge_base + BRIDGE_CAUSE_OFF);
-
+ disable_irq(timer_irq);
}
local_irq_restore(flags);
}
@@ -164,10 +144,6 @@ static struct clock_event_device orion_clkevt = {

static irqreturn_t orion_timer_interrupt(int irq, void *dev_id)
{
- /*
- * ACK timer interrupt and call event handler.
- */
- writel(bridge_timer1_clr_mask, bridge_base + BRIDGE_CAUSE_OFF);
orion_clkevt.event_handler(&orion_clkevt);

return IRQ_HANDLED;
@@ -186,16 +162,14 @@ orion_time_set_base(void __iomem *_timer_base)
}

void __init
-orion_time_init(void __iomem *_bridge_base, u32 _bridge_timer1_clr_mask,
- unsigned int irq, unsigned int tclk)
+orion_time_init(unsigned int irq, unsigned int tclk)
{
u32 u;

/*
* Set SoC-specific data.
*/
- bridge_base = _bridge_base;
- bridge_timer1_clr_mask = _bridge_timer1_clr_mask;
+ timer_irq = irq;

ticks_per_jiffy = (tclk + HZ/2) / HZ;

@@ -210,8 +184,6 @@ orion_time_init(void __iomem *_bridge_base, u32 _bridge_timer1_clr_mask,
*/
writel(0xffffffff, timer_base + TIMER0_VAL_OFF);
writel(0xffffffff, timer_base + TIMER0_RELOAD_OFF);
- u = readl(bridge_base + BRIDGE_MASK_OFF);
- writel(u & ~BRIDGE_INT_TIMER0, bridge_base + BRIDGE_MASK_OFF);
u = readl(timer_base + TIMER_CTRL_OFF);
writel(u | TIMER0_EN | TIMER0_RELOAD_EN, timer_base + TIMER_CTRL_OFF);
clocksource_mmio_init(timer_base + TIMER0_VAL_OFF, "orion_clocksource",
@@ -220,7 +192,7 @@ orion_time_init(void __iomem *_bridge_base, u32 _bridge_timer1_clr_mask,
/*
* Setup clockevent timer (interrupt-driven).
*/
- setup_irq(irq, &orion_timer_irq);
+ setup_irq(timer_irq, &orion_timer_irq);
orion_clkevt.mult = div_sc(tclk, NSEC_PER_SEC, orion_clkevt.shift);
orion_clkevt.max_delta_ns = clockevent_delta2ns(0xfffffffe, &orion_clkevt);
orion_clkevt.min_delta_ns = clockevent_delta2ns(1, &orion_clkevt);
--
1.7.5.4

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