ARM: gic: consolidate PPI handling

PPI handling is a bit of an odd beast. It uses its own low level
handling code and is hardwired to the local timers (hence lacking
a registration interface).

Instead, switch the low handling to the normal SPI handling code.
PPIs are handled by the handle_percpu_devid_irq flow.

This also allows the removal of some duplicated code.

Cc: Kukjin Kim <[email protected]>
Cc: David Brown <[email protected]>
Cc: Bryan Huntsman <[email protected]>
Cc: Tony Lindgren <[email protected]>
Cc: Paul Mundt <[email protected]>
Cc: Magnus Damm <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Acked-by: David Brown <[email protected]>
Tested-by: David Brown <[email protected]>
Tested-by: Shawn Guo <[email protected]>
Signed-off-by: Marc Zyngier <[email protected]>

Author: Marc Zyngier

arch/arm/common/gic.c

@@ -28,10 +28,14 @@
 #include <linux/smp.h>
 #include <linux/cpumask.h>
 #include <linux/io.h>
+#include <linux/interrupt.h>
+#include <linux/percpu.h>
+#include <linux/slab.h>
 
 #include <asm/irq.h>
 #include <asm/mach/irq.h>
 #include <asm/hardware/gic.h>
+#include <asm/localtimer.h>
 
 static DEFINE_SPINLOCK(irq_controller_lock);
 
@@ -255,13 +259,40 @@ void __init gic_cascade_irq(unsigned int gic_nr, unsigned int irq)
 	irq_set_chained_handler(irq, gic_handle_cascade_irq);
 }
 
+#ifdef CONFIG_LOCAL_TIMERS
+#define gic_ppi_handler		percpu_timer_handler
+#else
+static irqreturn_t gic_ppi_handler(int irq, void *dev_id)
+{
+	return IRQ_NONE;
+}
+#endif
+
+#define PPI_IRQACT(nr)						\
+	{							\
+		.handler	= gic_ppi_handler,		\
+		.flags		= IRQF_PERCPU | IRQF_TIMER,	\
+		.irq		= nr,				\
+		.name		= "PPI-" # nr,			\
+	}
+
+static struct irqaction ppi_irqaction_template[16] __initdata = {
+	PPI_IRQACT(0),  PPI_IRQACT(1),  PPI_IRQACT(2),  PPI_IRQACT(3),
+	PPI_IRQACT(4),  PPI_IRQACT(5),  PPI_IRQACT(6),  PPI_IRQACT(7),
+	PPI_IRQACT(8),  PPI_IRQACT(9),  PPI_IRQACT(10), PPI_IRQACT(11),
+	PPI_IRQACT(12), PPI_IRQACT(13), PPI_IRQACT(14), PPI_IRQACT(15),
+};
+
+static struct irqaction *ppi_irqaction;
+
 static void __init gic_dist_init(struct gic_chip_data *gic,
 	unsigned int irq_start)
 {
 	unsigned int gic_irqs, irq_limit, i;
 	u32 cpumask;
 	void __iomem *base = gic->dist_base;
 	u32 cpu = 0;
+	u32 nrppis = 0, ppi_base = 0;
 
 #ifdef CONFIG_SMP
 	cpu = cpu_logical_map(smp_processor_id());
@@ -282,6 +313,33 @@ static void __init gic_dist_init(struct gic_chip_data *gic,
 	if (gic_irqs > 1020)
 		gic_irqs = 1020;
 
+	/*
+	 * Nobody would be insane enough to use PPIs on a secondary
+	 * GIC, right?
+	 */
+	if (gic == &gic_data[0]) {
+		nrppis = (32 - irq_start) & 31;
+
+		/* The GIC only supports up to 16 PPIs. */
+		if (nrppis > 16)
+			BUG();
+
+		ppi_base = gic->irq_offset + 32 - nrppis;
+
+		ppi_irqaction = kmemdup(&ppi_irqaction_template[16 - nrppis],
+					sizeof(*ppi_irqaction) * nrppis,
+					GFP_KERNEL);
+
+		if (nrppis && !ppi_irqaction) {
+			pr_err("GIC: Can't allocate PPI memory");
+			nrppis = 0;
+			ppi_base = 0;
+		}
+	}
+
+	pr_info("Configuring GIC with %d sources (%d PPIs)\n",
+		gic_irqs, (gic == &gic_data[0]) ? nrppis : 0);
+
 	/*
 	 * Set all global interrupts to be level triggered, active low.
 	 */
@@ -317,7 +375,22 @@ static void __init gic_dist_init(struct gic_chip_data *gic,
 	/*
 	 * Setup the Linux IRQ subsystem.
 	 */
-	for (i = irq_start; i < irq_limit; i++) {
+	for (i = 0; i < nrppis; i++) {
+		int ppi = i + ppi_base;
+		int err;
+
+		irq_set_percpu_devid(ppi);
+		irq_set_chip_and_handler(ppi, &gic_chip,
+					 handle_percpu_devid_irq);
+		irq_set_chip_data(ppi, gic);
+		set_irq_flags(ppi, IRQF_VALID | IRQF_NOAUTOEN);
+
+		err = setup_percpu_irq(ppi, &ppi_irqaction[i]);
+		if (err)
+			pr_err("GIC: can't setup PPI%d (%d)\n", ppi, err);
+	}
+
+	for (i = irq_start + nrppis; i < irq_limit; i++) {
 		irq_set_chip_and_handler(i, &gic_chip, handle_fasteoi_irq);
 		irq_set_chip_data(i, gic);
 		set_irq_flags(i, IRQF_VALID | IRQF_PROBE);

arch/arm/include/asm/entry-macro-multi.S

@@ -25,13 +25,6 @@
 	movne	r1, sp
 	adrne	lr, BSYM(1b)
 	bne	do_IPI
-
-#ifdef CONFIG_LOCAL_TIMERS
-	test_for_ltirq r0, r2, r6, lr
-	movne	r0, sp
-	adrne	lr, BSYM(1b)
-	bne	do_local_timer
-#endif
 #endif
 9997:
 	.endm

arch/arm/include/asm/hardirq.h

@@ -9,9 +9,6 @@
 
 typedef struct {
 	unsigned int __softirq_pending;
-#ifdef CONFIG_LOCAL_TIMERS
-	unsigned int local_timer_irqs;
-#endif
 #ifdef CONFIG_SMP
 	unsigned int ipi_irqs[NR_IPI];
 #endif

arch/arm/include/asm/hardware/entry-macro-gic.S

@@ -22,15 +22,11 @@
  * interrupt controller spec.  To wit:
  *
  * Interrupts 0-15 are IPI
- * 16-28 are reserved
- * 29-31 are local.  We allow 30 to be used for the watchdog.
+ * 16-31 are local.  We allow 30 to be used for the watchdog.
  * 32-1020 are global
  * 1021-1022 are reserved
  * 1023 is "spurious" (no interrupt)
  *
- * For now, we ignore all local interrupts so only return an interrupt if it's
- * between 30 and 1020.  The test_for_ipi routine below will pick up on IPIs.
- *
  * A simple read from the controller will tell us the number of the highest
  * priority enabled interrupt.  We then just need to check whether it is in the
  * valid range for an IRQ (30-1020 inclusive).
@@ -43,7 +39,7 @@
 
 	ldr	\tmp, =1021
 	bic     \irqnr, \irqstat, #0x1c00
-	cmp     \irqnr, #29
+	cmp     \irqnr, #15
 	cmpcc	\irqnr, \irqnr
 	cmpne	\irqnr, \tmp
 	cmpcs	\irqnr, \irqnr
@@ -62,14 +58,3 @@
 	strcc	\irqstat, [\base, #GIC_CPU_EOI]
 	cmpcs	\irqnr, \irqnr
 	.endm
-
-/* As above, this assumes that irqstat and base are preserved.. */
-
-	.macro test_for_ltirq, irqnr, irqstat, base, tmp
-	bic	\irqnr, \irqstat, #0x1c00
-	mov 	\tmp, #0
-	cmp	\irqnr, #29
-	moveq	\tmp, #1
-	streq	\irqstat, [\base, #GIC_CPU_EOI]
-	cmp	\tmp, #0
-	.endm

arch/arm/include/asm/localtimer.h

@@ -10,6 +10,8 @@
 #ifndef __ASM_ARM_LOCALTIMER_H
 #define __ASM_ARM_LOCALTIMER_H
 
+#include <linux/interrupt.h>
+
 struct clock_event_device;
 
 /*
@@ -18,14 +20,9 @@ struct clock_event_device;
 void percpu_timer_setup(void);
 
 /*
- * Called from assembly, this is the local timer IRQ handler
- */
-asmlinkage void do_local_timer(struct pt_regs *);
-
-/*
- * Called from C code
+ * Per-cpu timer IRQ handler
  */
-void handle_local_timer(struct pt_regs *);
+irqreturn_t percpu_timer_handler(int irq, void *dev_id);
 
 #ifdef CONFIG_LOCAL_TIMERS
 

arch/arm/include/asm/smp.h

@@ -99,9 +99,4 @@ extern void platform_cpu_enable(unsigned int cpu);
 extern void arch_send_call_function_single_ipi(int cpu);
 extern void arch_send_call_function_ipi_mask(const struct cpumask *mask);
 
-/*
- * show local interrupt info
- */
-extern void show_local_irqs(struct seq_file *, int);
-
 #endif /* ifndef __ASM_ARM_SMP_H */

arch/arm/kernel/irq.c

@@ -58,9 +58,6 @@ int arch_show_interrupts(struct seq_file *p, int prec)
 #endif
 #ifdef CONFIG_SMP
 	show_ipi_list(p, prec);
-#endif
-#ifdef CONFIG_LOCAL_TIMERS
-	show_local_irqs(p, prec);
 #endif
 	seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count);
 	return 0;

arch/arm/kernel/smp.c

@@ -457,10 +457,6 @@ u64 smp_irq_stat_cpu(unsigned int cpu)
 	for (i = 0; i < NR_IPI; i++)
 		sum += __get_irq_stat(cpu, ipi_irqs[i]);
 
-#ifdef CONFIG_LOCAL_TIMERS
-	sum += __get_irq_stat(cpu, local_timer_irqs);
-#endif
-
 	return sum;
 }
 
@@ -478,34 +474,16 @@ static void ipi_timer(void)
 }
 
 #ifdef CONFIG_LOCAL_TIMERS
-asmlinkage void __exception_irq_entry do_local_timer(struct pt_regs *regs)
-{
-	handle_local_timer(regs);
-}
-
-void handle_local_timer(struct pt_regs *regs)
+irqreturn_t percpu_timer_handler(int irq, void *dev_id)
 {
-	struct pt_regs *old_regs = set_irq_regs(regs);
-	int cpu = smp_processor_id();
+	struct clock_event_device *evt = &__get_cpu_var(percpu_clockevent);
 
 	if (local_timer_ack()) {
-		__inc_irq_stat(cpu, local_timer_irqs);
-		ipi_timer();
+		evt->event_handler(evt);
+		return IRQ_HANDLED;
 	}
 
-	set_irq_regs(old_regs);
-}
-
-void show_local_irqs(struct seq_file *p, int prec)
-{
-	unsigned int cpu;
-
-	seq_printf(p, "%*s: ", prec, "LOC");
-
-	for_each_present_cpu(cpu)
-		seq_printf(p, "%10u ", __get_irq_stat(cpu, local_timer_irqs));
-
-	seq_printf(p, " Local timer interrupts\n");
+	return IRQ_NONE;
 }
 #endif
 

arch/arm/mach-exynos4/include/mach/entry-macro.S

@@ -55,7 +55,7 @@
 
 		bic     \irqnr, \irqstat, #0x1c00
 
-		cmp     \irqnr, #29
+		cmp     \irqnr, #15
 		cmpcc	\irqnr, \irqnr
 		cmpne	\irqnr, \tmp
 		cmpcs	\irqnr, \irqnr
@@ -76,8 +76,3 @@
 		strcc	\irqstat, [\base, #GIC_CPU_EOI]
 		cmpcs	\irqnr, \irqnr
 		.endm
-
-		/* As above, this assumes that irqstat and base are preserved.. */
-
-		.macro test_for_ltirq, irqnr, irqstat, base, tmp
-		.endm

arch/arm/mach-msm/board-msm8x60.c

@@ -36,8 +36,6 @@ static void __init msm8x60_map_io(void)
 
 static void __init msm8x60_init_irq(void)
 {
-	unsigned int i;
-
 	gic_init(0, GIC_PPI_START, MSM_QGIC_DIST_BASE,
 		 (void *)MSM_QGIC_CPU_BASE);
 
@@ -49,15 +47,6 @@ static void __init msm8x60_init_irq(void)
 	 */
 	if (!machine_is_msm8x60_sim())
 		writel(0x0000FFFF, MSM_QGIC_DIST_BASE + GIC_DIST_ENABLE_SET);
-
-	/* FIXME: Not installing AVS_SVICINT and AVS_SVICINTSWDONE yet
-	 * as they are configured as level, which does not play nice with
-	 * handle_percpu_irq.
-	 */
-	for (i = GIC_PPI_START; i < GIC_SPI_START; i++) {
-		if (i != AVS_SVICINT && i != AVS_SVICINTSWDONE)
-			irq_set_handler(i, handle_percpu_irq);
-	}
 }
 
 static void __init msm8x60_init(void)