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authorDavid VomLehn <dvomlehn@cisco.com>2009-12-21 17:49:22 -0800
committerRalf Baechle <ralf@linux-mips.org>2010-01-28 00:03:31 +0100
commit010c108d7af708d9e09b83724a058a76803fbc66 (patch)
tree6b7108e6852b0306ecd686a8ce9b9ae5733985fa /arch/mips/kernel/traps.c
parent59dfa2fcaecc39fb88bfa196cb15adca7146867a (diff)
downloadblackbird-op-linux-010c108d7af708d9e09b83724a058a76803fbc66.tar.gz
blackbird-op-linux-010c108d7af708d9e09b83724a058a76803fbc66.zip
MIPS: PowerTV: Fix support for timer interrupts with > 64 external IRQs
The MIPS processor is limited to 64 external interrupt sources. Using a greater number without IRQ sharing requires reading platform-specific registers. On such platforms, reading the IntCtl register to determine which interrupt corresponds to a timer interrupt will not work. On MIPSR2 systems there is a solution - the TI bit in the Cause register, specifically indicates that a timer interrupt has occured. This patch uses that bit to detect interrupts for MIPSR2 processors, which may be expected to work regardless of how the timer interrupt may be routed in the hardware. Signed-off-by: David VomLehn (dvomlehn@cisco.com) To: linux-mips@linux-mips.org Patchwork: http://patchwork.linux-mips.org/patch/804/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/kernel/traps.c')
-rw-r--r--arch/mips/kernel/traps.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 308e43460864..338dfe8ed002 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -1403,6 +1403,7 @@ extern void flush_tlb_handlers(void);
* Timer interrupt
*/
int cp0_compare_irq;
+int cp0_compare_irq_shift;
/*
* Performance counter IRQ or -1 if shared with timer
@@ -1493,8 +1494,9 @@ void __cpuinit per_cpu_trap_init(void)
* o read IntCtl.IPPCI to determine the performance counter interrupt
*/
if (cpu_has_mips_r2) {
- cp0_compare_irq = (read_c0_intctl() >> 29) & 7;
- cp0_perfcount_irq = (read_c0_intctl() >> 26) & 7;
+ cp0_compare_irq_shift = CAUSEB_TI - CAUSEB_IP;
+ cp0_compare_irq = (read_c0_intctl() >> INTCTLB_IPTI) & 7;
+ cp0_perfcount_irq = (read_c0_intctl() >> INTCTLB_IPPCI) & 7;
if (cp0_perfcount_irq == cp0_compare_irq)
cp0_perfcount_irq = -1;
} else {
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