Re: [Qemu-devel] State of ARM FIQ in Qemu

[Tim Sander <tim@krieglstein.org>]

Hi Greg
> Ah... Yes, using A9 (GICv1) which means you don't have grouping without the
> security extensions. 
Ok switching the GIC to version 2 works seems to work. In a way that Linux still
boots up and i get a FIQ.

I have some problems still:
It seems as if the exeption of the bugsplat below 
is called from handle_fasteoi_irq (or is it just interrupted?). Which would mean
that the cpu is not jumping to the FIQ handler but the normal irq handler. This
might point to a problem in the qemu FIQ code. But i am not sure, so the error
might also be in the linux user mode.

I have loaded a firmware my driver module with "set_fiq_handler" but the area
where the fiq has landed (0xfff1240) is filled completly with zeros?

Best regards
Tim

Bad mode in data abort handler detected
Internal error: Oops - bad mode: 0 [#1] PREEMPT SMP ARM
Modules linked in: firq(O) ipv6
CPU: 0 PID: 103 Comm: systemd-udevd Tainted: G           O 3.14.0 #1
task: bf2b9300 ti: bf362000 task.ti: bf362000
PC is at 0xffff1240
LR is at handle_fasteoi_irq+0x9c/0x13c
pc : [<ffff1240>]    lr : [<8005cda0>]    psr: 600f01d1
sp : bf363e70  ip : 07a7e79d  fp : 00000000
r10: 76f92008  r9 : 80590080  r8 : 76e8e4d0
r7 : f8200100  r6 : bf363fb0  r5 : bf008414  r4 : bf0083c0
r3 : 80230d04  r2 : 0000002f  r1 : 00000000  r0 : bf0083c0
Flags: nZCv  IRQs off  FIQs off  Mode FIQ_32  ISA ARM  Segment user
Control: 10c53c7d  Table: 60004059  DAC: 00000015
Process systemd-udevd (pid: 103, stack limit = 0xbf362240)
Stack: (0xbf363e70 to 0xbf364000)
3e60:                                     bf0083c0 00000000 0000002f 80230d04
3e80: bf0083c0 bf008414 bf363fb0 f8200100 76e8e4d0 80590080 76f92008 00000000
3ea0: 07a7e79d bf363e70 8005cda0 ffff1240 600f01d1 ffffffff 8005cd04 0000002f
3ec0: 0000002f 800598bc 8058cc70 8000ed00 f820010c 8059684c bf363ef8 80008528
3ee0: 80023730 80023744 200f0113 ffffffff bf363f2c 80012180 00000000 805baa00
3f00: 00000000 00000100 00000002 00000022 00000000 bf362000 76e8e4d0 80590080
3f20: 76f92008 00000000 0000000a bf363f40 80023730 80023744 200f0113 ffffffff
3f40: bf007a14 8059ac00 00000000 0000000a ffff8dd7 00400140 bf0079c0 8058cc70
3f60: 00000022 00000000 f8200100 76e8e4d0 76f9201c 76f92008 00000000 80023af0
3f80: 8058cc70 8000ed04 f820010c 8059684c bf363fb0 80008528 00000000 76dd3b44
3fa0: 600f0010 ffffffff 0000000c 8001233c 00000000 00000000 76f93428 76f93428
3fc0: 76f93438 00000000 76f93448 0000000c 76e8e4d0 76f9201c 76f92008 00000000
3fe0: 00000000 7ec115c0 76f60914 76dd3b44 600f0010 ffffffff 9fffd821 9fffdc21
[<8005cda0>] (handle_fasteoi_irq) from [<80230d04>] (gic_eoi_irq+0x0/0x4c)
[<80230d04>] (gic_eoi_irq) from [<f8200100>] (0xf8200100)
Code: ee02af10 f57ff06f e59d8000 e59d9004 (e599b00c) 
---[ end trace 3dc3571209a017e1 ]---
Kernel panic - not syncing: Fatal exception in interrupt