[RFC PATCH 2/3] ARM: gic: consolidate PPI handling

From: Marc Zyngier
Date: Thu Sep 15 2011 - 12:52:31 EST


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 <kgene.kim@xxxxxxxxxxx>
Cc: David Brown <davidb@xxxxxxxxxxxxxx>
Cc: Bryan Huntsman <bryanh@xxxxxxxxxxxxxx>
Cc: Tony Lindgren <tony@xxxxxxxxxxx>
Cc: Paul Mundt <lethal@xxxxxxxxxxxx>
Cc: Magnus Damm <magnus.damm@xxxxxxxxx>
Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
---
arch/arm/common/Kconfig | 1 +
arch/arm/common/gic.c | 70 +++++++++++++++++++-
arch/arm/include/asm/entry-macro-multi.S | 7 --
arch/arm/include/asm/hardirq.h | 3 -
arch/arm/include/asm/hardware/entry-macro-gic.S | 19 +-----
arch/arm/include/asm/localtimer.h | 6 +-
arch/arm/include/asm/smp.h | 5 --
arch/arm/kernel/irq.c | 3 -
arch/arm/kernel/smp.c | 27 ++------
arch/arm/mach-exynos4/include/mach/entry-macro.S | 6 +--
arch/arm/mach-msm/board-msm8x60.c | 11 ---
arch/arm/mach-msm/include/mach/entry-macro-qgic.S | 73 +--------------------
arch/arm/mach-omap2/include/mach/entry-macro.S | 14 +----
arch/arm/mach-shmobile/entry-intc.S | 3 -
arch/arm/mach-shmobile/include/mach/entry-macro.S | 3 -
15 files changed, 84 insertions(+), 167 deletions(-)

diff --git a/arch/arm/common/Kconfig b/arch/arm/common/Kconfig
index 4b71766..114a432 100644
--- a/arch/arm/common/Kconfig
+++ b/arch/arm/common/Kconfig
@@ -1,4 +1,5 @@
config ARM_GIC
+ select IRQ_PERCPU_DEVID
bool

config ARM_VIC
diff --git a/arch/arm/common/gic.c b/arch/arm/common/gic.c
index 666b278..4bbcce8 100644
--- a/arch/arm/common/gic.c
+++ b/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);

@@ -255,6 +259,32 @@ 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)
{
@@ -262,6 +292,7 @@ static void __init gic_dist_init(struct gic_chip_data *gic,
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());
@@ -283,6 +314,28 @@ static void __init gic_dist_init(struct gic_chip_data *gic,
gic_irqs = 1020;

/*
+ * Nobody would be insane enough to use PPIs on a secondary
+ * GIC, right?
+ */
+ if (gic == &gic_data[0]) {
+ nrppis = 16 - (irq_start & 15);
+ 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.
*/
for (i = 32; i < gic_irqs; i += 16)
@@ -317,7 +370,22 @@ 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);
diff --git a/arch/arm/include/asm/entry-macro-multi.S b/arch/arm/include/asm/entry-macro-multi.S
index 2f1e209..88d6181 100644
--- a/arch/arm/include/asm/entry-macro-multi.S
+++ b/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
diff --git a/arch/arm/include/asm/hardirq.h b/arch/arm/include/asm/hardirq.h
index 89ad180..ddf07a9 100644
--- a/arch/arm/include/asm/hardirq.h
+++ b/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
diff --git a/arch/arm/include/asm/hardware/entry-macro-gic.S b/arch/arm/include/asm/hardware/entry-macro-gic.S
index c115b82..74ebc80 100644
--- a/arch/arm/include/asm/hardware/entry-macro-gic.S
+++ b/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
diff --git a/arch/arm/include/asm/localtimer.h b/arch/arm/include/asm/localtimer.h
index 080d74f..e3663f7 100644
--- a/arch/arm/include/asm/localtimer.h
+++ b/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;

/*
@@ -18,9 +20,9 @@ struct clock_event_device;
void percpu_timer_setup(void);

/*
- * Called from assembly, this is the local timer IRQ handler
+ * Per-cpu timer IRQ handler
*/
-asmlinkage void do_local_timer(struct pt_regs *);
+irqreturn_t percpu_timer_handler(int irq, void *dev_id);


#ifdef CONFIG_LOCAL_TIMERS
diff --git a/arch/arm/include/asm/smp.h b/arch/arm/include/asm/smp.h
index 674ebcd..7c2299f 100644
--- a/arch/arm/include/asm/smp.h
+++ b/arch/arm/include/asm/smp.h
@@ -94,9 +94,4 @@ 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 */
diff --git a/arch/arm/kernel/irq.c b/arch/arm/kernel/irq.c
index e20a5d0..8e744f6 100644
--- a/arch/arm/kernel/irq.c
+++ b/arch/arm/kernel/irq.c
@@ -58,9 +58,6 @@ int arch_show_interrupts(struct seq_file *p, int prec)
#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;
}
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index 04d7b80..e3dbd99 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -504,10 +504,6 @@ 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;
}

@@ -525,29 +521,16 @@ static void ipi_timer(void)
}

#ifdef CONFIG_LOCAL_TIMERS
-asmlinkage void __exception_irq_entry do_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

diff --git a/arch/arm/mach-exynos4/include/mach/entry-macro.S b/arch/arm/mach-exynos4/include/mach/entry-macro.S
index d7a1e28..807d05d 100644
--- a/arch/arm/mach-exynos4/include/mach/entry-macro.S
+++ b/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
@@ -77,7 +77,3 @@
cmpcs \irqnr, \irqnr
.endm

- /* As above, this assumes that irqstat and base are preserved.. */
-
- .macro test_for_ltirq, irqnr, irqstat, base, tmp
- .endm
diff --git a/arch/arm/mach-msm/board-msm8x60.c b/arch/arm/mach-msm/board-msm8x60.c
index 9221f54..106170f 100644
--- a/arch/arm/mach-msm/board-msm8x60.c
+++ b/arch/arm/mach-msm/board-msm8x60.c
@@ -53,8 +53,6 @@ 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);

@@ -66,15 +64,6 @@ 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)
diff --git a/arch/arm/mach-msm/include/mach/entry-macro-qgic.S b/arch/arm/mach-msm/include/mach/entry-macro-qgic.S
index 1246715..717076f 100644
--- a/arch/arm/mach-msm/include/mach/entry-macro-qgic.S
+++ b/arch/arm/mach-msm/include/mach/entry-macro-qgic.S
@@ -8,81 +8,10 @@
* warranty of any kind, whether express or implied.
*/

-#include <mach/hardware.h>
-#include <asm/hardware/gic.h>
+#include <asm/hardware/entry-macro-gic.S>

.macro disable_fiq
.endm

- .macro get_irqnr_preamble, base, tmp
- ldr \base, =gic_cpu_base_addr
- ldr \base, [\base]
- .endm
-
.macro arch_ret_to_user, tmp1, tmp2
.endm
-
- /*
- * The interrupt numbering scheme is defined in the
- * interrupt controller spec. To wit:
- *
- * Migrated the code from ARM MP port to be more consistent
- * with interrupt processing , the following still holds true
- * however, all interrupts are treated the same regardless of
- * if they are local IPI or PPI
- *
- * Interrupts 0-15 are IPI
- * 16-31 are PPI
- * (16-18 are the timers)
- * 32-1020 are global
- * 1021-1022 are reserved
- * 1023 is "spurious" (no interrupt)
- *
- * 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 (0-1020 inclusive).
- *
- * Base ARM code assumes that the local (private) peripheral interrupts
- * are not valid, we treat them differently, in that the privates are
- * handled like normal shared interrupts with the exception that only
- * one processor can register the interrupt and the handler must be
- * the same for all processors.
- */
-
- .macro get_irqnr_and_base, irqnr, irqstat, base, tmp
-
- ldr \irqstat, [\base, #GIC_CPU_INTACK] /* bits 12-10 =srcCPU,
- 9-0 =int # */
-
- bic \irqnr, \irqstat, #0x1c00 @mask src
- cmp \irqnr, #15
- ldr \tmp, =1021
- cmpcc \irqnr, \irqnr
- cmpne \irqnr, \tmp
- cmpcs \irqnr, \irqnr
-
- .endm
-
- /* We assume that irqstat (the raw value of the IRQ acknowledge
- * register) is preserved from the macro above.
- * If there is an IPI, we immediately signal end of interrupt on the
- * controller, since this requires the original irqstat value which
- * we won't easily be able to recreate later.
- */
- .macro test_for_ipi, irqnr, irqstat, base, tmp
- bic \irqnr, \irqstat, #0x1c00
- cmp \irqnr, #16
- 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, #16
- moveq \tmp, #1
- streq \irqstat, [\base, #GIC_CPU_EOI]
- cmp \tmp, #0
- .endm
diff --git a/arch/arm/mach-omap2/include/mach/entry-macro.S b/arch/arm/mach-omap2/include/mach/entry-macro.S
index ceb8b7e..feb90a1 100644
--- a/arch/arm/mach-omap2/include/mach/entry-macro.S
+++ b/arch/arm/mach-omap2/include/mach/entry-macro.S
@@ -78,7 +78,7 @@
4401: ldr \irqstat, [\base, #GIC_CPU_INTACK]
ldr \tmp, =1021
bic \irqnr, \irqstat, #0x1c00
- cmp \irqnr, #29
+ cmp \irqnr, #15
cmpcc \irqnr, \irqnr
cmpne \irqnr, \tmp
cmpcs \irqnr, \irqnr
@@ -101,18 +101,6 @@
it cs
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
- itt eq
- moveq \tmp, #1
- streq \irqstat, [\base, #GIC_CPU_EOI]
- cmp \tmp, #0
- .endm
#endif /* CONFIG_SMP */

#else /* MULTI_OMAP2 */
diff --git a/arch/arm/mach-shmobile/entry-intc.S b/arch/arm/mach-shmobile/entry-intc.S
index cac0a7a..1a1c00c 100644
--- a/arch/arm/mach-shmobile/entry-intc.S
+++ b/arch/arm/mach-shmobile/entry-intc.S
@@ -51,7 +51,4 @@
.macro test_for_ipi, irqnr, irqstat, base, tmp
.endm

- .macro test_for_ltirq, irqnr, irqstat, base, tmp
- .endm
-
arch_irq_handler shmobile_handle_irq_intc
diff --git a/arch/arm/mach-shmobile/include/mach/entry-macro.S b/arch/arm/mach-shmobile/include/mach/entry-macro.S
index d791f10..8d4a416 100644
--- a/arch/arm/mach-shmobile/include/mach/entry-macro.S
+++ b/arch/arm/mach-shmobile/include/mach/entry-macro.S
@@ -27,8 +27,5 @@
.macro test_for_ipi, irqnr, irqstat, base, tmp
.endm

- .macro test_for_ltirq, irqnr, irqstat, base, tmp
- .endm
-
.macro arch_ret_to_user, tmp1, tmp2
.endm
--
1.7.0.4


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