MIPS: DEC: Implement FPU interrupt counter
Implement a cheap way to count FPU interrupts for R2k/R3k DECstation
systems. Do this manually in handcoded assembly, rather than calling
`kstat_incr_irq_this_cpu' that would require setting up a stack frame
and a lot of redirection. This is not going to be a problem because the
FPU interrupt is local to the CPU and also there is one CPU only anyway.
So at bootstrap determine the address of the correct location within
`struct irq_desc', and then only refer to it directly in the interrupt
handler.
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9713/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/dec/int-handler.S b/arch/mips/dec/int-handler.S
index 41a2fa1..8c6f508 100644
--- a/arch/mips/dec/int-handler.S
+++ b/arch/mips/dec/int-handler.S
@@ -267,8 +267,13 @@
#ifdef CONFIG_32BIT
fpu:
+ lw t0,fpu_kstat_irq
+ nop
+ lw t1,(t0)
+ nop
+ addu t1,1
j handle_fpe_int
- nop
+ sw t1,(t0)
#endif
spurious: