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authorRalf Baechle <ralf@linux-mips.org>2015-06-09 15:04:38 +0200
committerRalf Baechle <ralf@linux-mips.org>2015-06-21 21:54:31 +0200
commitcb2224d7c40e3d2dfc6f4a1676cd817acc79f012 (patch)
tree7ef2588fb1835b73bd0077958986acad0eb60e02 /arch/mips/sgi-ip27
parent6f6ed482653723e53da4a57b200348ac1eed5ce9 (diff)
MIPS: IRQ/IP27: Move IRQ allocation API to platform code.
allocate_irqno, free_irqno and alloc_legacy_irqno are a simple allocator for interrupt numbers from the days when the numer of interrupts was still fixed to NR_IRQS. This was necessary for the SGI IP27 architecture which with its flexible architecture and possibly large number of interrupts doesn't easily fit into the old pattern. These days there are better alternatives. Move the allocation code from the arch generic code to the only platform using it, the SGI IP27 aka Origin 200/2000, Onyx 2. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/sgi-ip27')
-rw-r--r--arch/mips/sgi-ip27/Makefile6
-rw-r--r--arch/mips/sgi-ip27/ip27-irqno.c48
2 files changed, 51 insertions, 3 deletions
diff --git a/arch/mips/sgi-ip27/Makefile b/arch/mips/sgi-ip27/Makefile
index da8f6816d346..ab4affa626c7 100644
--- a/arch/mips/sgi-ip27/Makefile
+++ b/arch/mips/sgi-ip27/Makefile
@@ -2,9 +2,9 @@
# Makefile for the IP27 specific kernel interface routines under Linux.
#
-obj-y := ip27-berr.o ip27-irq.o ip27-init.o ip27-klconfig.o ip27-klnuma.o \
- ip27-memory.o ip27-nmi.o ip27-reset.o ip27-timer.o ip27-hubio.o \
- ip27-xtalk.o
+obj-y := ip27-berr.o ip27-irq.o ip27-irqno.o ip27-init.o ip27-klconfig.o \
+ ip27-klnuma.o ip27-memory.o ip27-nmi.o ip27-reset.o ip27-timer.o \
+ ip27-hubio.o ip27-xtalk.o
obj-$(CONFIG_EARLY_PRINTK) += ip27-console.o
obj-$(CONFIG_PCI) += ip27-irq-pci.o
diff --git a/arch/mips/sgi-ip27/ip27-irqno.c b/arch/mips/sgi-ip27/ip27-irqno.c
new file mode 100644
index 000000000000..957ab58e1c00
--- /dev/null
+++ b/arch/mips/sgi-ip27/ip27-irqno.c
@@ -0,0 +1,48 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/types.h>
+
+#include <asm/barrier.h>
+
+static DECLARE_BITMAP(irq_map, NR_IRQS);
+
+int allocate_irqno(void)
+{
+ int irq;
+
+again:
+ irq = find_first_zero_bit(irq_map, NR_IRQS);
+
+ if (irq >= NR_IRQS)
+ return -ENOSPC;
+
+ if (test_and_set_bit(irq, irq_map))
+ goto again;
+
+ return irq;
+}
+
+/*
+ * Allocate the 16 legacy interrupts for i8259 devices. This happens early
+ * in the kernel initialization so treating allocation failure as BUG() is
+ * ok.
+ */
+void __init alloc_legacy_irqno(void)
+{
+ int i;
+
+ for (i = 0; i <= 16; i++)
+ BUG_ON(test_and_set_bit(i, irq_map));
+}
+
+void free_irqno(unsigned int irq)
+{
+ smp_mb__before_atomic();
+ clear_bit(irq, irq_map);
+ smp_mb__after_atomic();
+}