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authorKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>2005-04-25 13:26:23 -0700
committerTony Luck <tony.luck@intel.com>2005-04-25 13:26:23 -0700
commit24eeb568aeeaee771b9f0a6fd6f5d01040a887da (patch)
tree4d3e731845cde292b5a40ff7db97cce639dc073c /arch/ia64/kernel/irq_ia64.c
parente927ecb05e1ce4bbb1e10f57008c94994e2160f5 (diff)
downloadop-kernel-dev-24eeb568aeeaee771b9f0a6fd6f5d01040a887da.zip
op-kernel-dev-24eeb568aeeaee771b9f0a6fd6f5d01040a887da.tar.gz
[IA64] vector sharing (Large I/O system support)
Current ia64 linux cannot handle greater than 184 interrupt sources because of the lack of vectors. The following patch enables ia64 linux to handle greater than 184 interrupt sources by allowing the same vector number to be shared by multiple IOSAPIC's RTEs. The design of this patch is besed on "Intel(R) Itanium(R) Processor Family Interrupt Architecture Guide". Even if you don't have a large I/O system, you can see the behavior of vector sharing by changing IOSAPIC_LAST_DEVICE_VECTOR to fewer value. Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
Diffstat (limited to 'arch/ia64/kernel/irq_ia64.c')
-rw-r--r--arch/ia64/kernel/irq_ia64.c16
1 files changed, 13 insertions, 3 deletions
diff --git a/arch/ia64/kernel/irq_ia64.c b/arch/ia64/kernel/irq_ia64.c
index 5ba06eb..4fe60c7 100644
--- a/arch/ia64/kernel/irq_ia64.c
+++ b/arch/ia64/kernel/irq_ia64.c
@@ -63,20 +63,30 @@ EXPORT_SYMBOL(isa_irq_to_vector_map);
static unsigned long ia64_vector_mask[BITS_TO_LONGS(IA64_NUM_DEVICE_VECTORS)];
int
-assign_irq_vector (int irq)
+assign_irq_vector_nopanic (int irq)
{
int pos, vector;
again:
pos = find_first_zero_bit(ia64_vector_mask, IA64_NUM_DEVICE_VECTORS);
vector = IA64_FIRST_DEVICE_VECTOR + pos;
if (vector > IA64_LAST_DEVICE_VECTOR)
- /* XXX could look for sharable vectors instead of panic'ing... */
- panic("assign_irq_vector: out of interrupt vectors!");
+ return -1;
if (test_and_set_bit(pos, ia64_vector_mask))
goto again;
return vector;
}
+int
+assign_irq_vector (int irq)
+{
+ int vector = assign_irq_vector_nopanic(irq);
+
+ if (vector < 0)
+ panic("assign_irq_vector: out of interrupt vectors!");
+
+ return vector;
+}
+
void
free_irq_vector (int vector)
{
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