MIPS: Read CPU IRQ line that FDC to routed to

Read the CPU IRQ line reportedly used for the Fast Debug Channel (FDC)
interrupt from the IntCtl register and store it in cp0_fdc_irq where
platform implementations of the new weak platform function
get_c0_fdc_int() can refer to it.

[ralf@linux-mips.org: Fixed conflict.]

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: James Hogan <james.hogan@imgtec.com>
Patchwork: https://patchwork.linux-mips.org/patch/9140/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

diff --git a/arch/mips/include/asm/irq.h b/arch/mips/include/asm/irq.h
index 5a4e1bb8fb1be99e98c372efa5138b7f7681ebbc..f0db99f8defe9b5ef17a7f39e6861916a85acd12 100644 (file)
--- a/arch/mips/include/asm/irq.h
+++ b/arch/mips/include/asm/irq.h
@@ -47,6 +47,9 @@ extern void free_irqno(unsigned int irq);
 extern int cp0_compare_irq;
 extern int cp0_compare_irq_shift;
 extern int cp0_perfcount_irq;
+extern int cp0_fdc_irq;
+
+extern int __weak get_c0_fdc_int(void);
 
 void arch_trigger_all_cpu_backtrace(bool);
 #define arch_trigger_all_cpu_backtrace arch_trigger_all_cpu_backtrace

diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 424567cfeb3d3609f0c1bf1ed732171c44793599..b0210b0651978ab6d6d5fd9bd23266a6058af50c 100644 (file)
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -1969,6 +1969,12 @@ int cp0_compare_irq_shift;
 int cp0_perfcount_irq;
 EXPORT_SYMBOL_GPL(cp0_perfcount_irq);
 
+/*
+ * Fast debug channel IRQ or -1 if not present
+ */
+int cp0_fdc_irq;
+EXPORT_SYMBOL_GPL(cp0_fdc_irq);
+
 static int noulri;
 
 static int __init ulri_disable(char *s)
@@ -2050,15 +2056,21 @@ void per_cpu_trap_init(bool is_boot_cpu)
         *
         *  o read IntCtl.IPTI to determine the timer interrupt
         *  o read IntCtl.IPPCI to determine the performance counter interrupt
+        *  o read IntCtl.IPFDC to determine the fast debug channel interrupt
         */
        if (cpu_has_mips_r2_r6) {
                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;
+               cp0_fdc_irq = (read_c0_intctl() >> INTCTLB_IPFDC) & 7;
+               if (!cp0_fdc_irq)
+                       cp0_fdc_irq = -1;
+
        } else {
                cp0_compare_irq = CP0_LEGACY_COMPARE_IRQ;
                cp0_compare_irq_shift = CP0_LEGACY_PERFCNT_IRQ;
                cp0_perfcount_irq = -1;
+               cp0_fdc_irq = -1;
        }
 
        if (!cpu_data[cpu].asid_cache)