[PATCH] ARM: orion: provide C-style interrupt handler for MULTI_IRQ_HANDLER

From: Sebastian Hesselbarth
Date: Thu Jan 16 2014 - 03:11:18 EST


DT-enabled Marvell Kirkwood and Dove SoCs make use of an irqchip
driver. As expected for irqchip drivers, it uses a C-style
interrupt handler and therefore selects MULTI_IRQ_HANDLER.

Now, compiling a kernel with both non-DT and DT support enabled,
selecting MULTI_IRQ_HANDLER will break ASM irq handler used by
non-DT boards.

Therefore, we provide a C-style irq handler even for non-DT boards,
if MULTI_IRQ_HANDLER is set. By installing the C-style irq handler
in orion_irq_init this is transparent to all non-DT board files.

While the regression report was filed on Marvell Kirkwood, also
Marvell Dove non-DT boards are affected and fixed by this patch.

Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@xxxxxxxxx>
Tested-by: Ian Campbell <ijc@xxxxxxxxxxxxxx>
Reported-by: Ian Campbell <ijc@xxxxxxxxxxxxxx>
Fixes: 2326f04321a9 ("ARM: kirkwood: convert to DT irqchip and clocksource")
Fixes: f07d73e33d0e ("ARM: dove: convert to DT irqchip and clocksource")
---
Compared to the two patch version sent on Ian's regression report,
I cooked this down to a single patch only touching plat-orion/irq.c.
I also dropped Orion5x and MV78x00, as they not yet select MULTI_IRQ_HANDLER
at all. Instead I added a comment about taking care of them, as soon as
they move over to an irqchip driver themselves.

I have not yet Cc'ed this patch to -stable to get some discussion and
an Acked-by from Jason or Andrew, too.

Cc: Jason Cooper <jason@xxxxxxxxxxxxxx>
Cc: Andrew Lunn <andrew@xxxxxxx>
Cc: Sebastian Hesselbarth <sebastian.hesselbarth@xxxxxxxxx>
Cc: Russell King <linux@xxxxxxxxxxxxxxxx>
Cc: Ian Campbell <ijc@xxxxxxxxxxxxxx>
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
arch/arm/plat-orion/irq.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 47 insertions(+)

diff --git a/arch/arm/plat-orion/irq.c b/arch/arm/plat-orion/irq.c
index c492e1b3dfdb..807df142444b 100644
--- a/arch/arm/plat-orion/irq.c
+++ b/arch/arm/plat-orion/irq.c
@@ -15,8 +15,51 @@
#include <linux/io.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
+#include <asm/exception.h>
#include <plat/irq.h>
#include <plat/orion-gpio.h>
+#include <mach/bridge-regs.h>
+
+#ifdef CONFIG_MULTI_IRQ_HANDLER
+/*
+ * Compiling with both non-DT and DT support enabled, will
+ * break asm irq handler used by non-DT boards. Therefore,
+ * we provide a C-style irq handler even for non-DT boards,
+ * if MULTI_IRQ_HANDLER is set.
+ *
+ * Notes:
+ * - this is prepared for Kirkwood and Dove only, update
+ * accordingly if you add Orion5x or MV78x00.
+ * - Orion5x uses different macro names and has only one
+ * set of CAUSE/MASK registers.
+ * - MV78x00 uses the same macro names but has a third
+ * set of CAUSE/MASK registers.
+ *
+ */
+
+static void __iomem *orion_irq_base = IRQ_VIRT_BASE;
+
+asmlinkage void
+__exception_irq_entry orion_legacy_handle_irq(struct pt_regs *regs)
+{
+ u32 stat;
+
+ stat = readl_relaxed(orion_irq_base + IRQ_CAUSE_LOW_OFF);
+ stat &= readl_relaxed(orion_irq_base + IRQ_MASK_LOW_OFF);
+ if (stat) {
+ unsigned int hwirq = __fls(stat);
+ handle_IRQ(hwirq, regs);
+ return;
+ }
+ stat = readl_relaxed(orion_irq_base + IRQ_CAUSE_HIGH_OFF);
+ stat &= readl_relaxed(orion_irq_base + IRQ_MASK_HIGH_OFF);
+ if (stat) {
+ unsigned int hwirq = 32 + __fls(stat);
+ handle_IRQ(hwirq, regs);
+ return;
+ }
+}
+#endif

void __init orion_irq_init(unsigned int irq_start, void __iomem *maskaddr)
{
@@ -35,6 +78,10 @@ void __init orion_irq_init(unsigned int irq_start, void __iomem *maskaddr)
ct->chip.irq_unmask = irq_gc_mask_set_bit;
irq_setup_generic_chip(gc, IRQ_MSK(32), IRQ_GC_INIT_MASK_CACHE,
IRQ_NOREQUEST, IRQ_LEVEL | IRQ_NOPROBE);
+
+#ifdef CONFIG_MULTI_IRQ_HANDLER
+ set_handle_irq(orion_legacy_handle_irq);
+#endif
}

#ifdef CONFIG_OF
--
1.8.5.2

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