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authorIngo Molnar <mingo@kernel.org>2015-08-25 09:59:19 +0200
committerIngo Molnar <mingo@kernel.org>2015-08-25 09:59:19 +0200
commit8d58b66ed2b000f27658c88a4ed70e8042e86a58 (patch)
tree5bae2c74f932b5d863f72cb698a6f71260340b26 /arch/mips/sgi-ip27/ip27-irqno.c
parent13fe86f465b72fc9328d4f5ebc33223c011852ae (diff)
parentc13dcf9f2d6f5f06ef1bf79ec456df614c5e058b (diff)
downloadtalos-op-linux-8d58b66ed2b000f27658c88a4ed70e8042e86a58.tar.gz
talos-op-linux-8d58b66ed2b000f27658c88a4ed70e8042e86a58.zip
Merge tag 'v4.2-rc8' into x86/mm, before applying new changes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/mips/sgi-ip27/ip27-irqno.c')
-rw-r--r--arch/mips/sgi-ip27/ip27-irqno.c48
1 files changed, 48 insertions, 0 deletions
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();
+}
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