Re: [PATCH] ARM64: ZynqMP: DT: Fix GIC's 'reg' property

[Michal Simek <michal.simek@xilinx.com>]

Hi,

On 15.12.2015 10:14, Sören Brinkmann wrote:
> On Mon, 2015-12-14 at 05:01PM +0000, Marc Zyngier wrote:
>> Mark,
>>
>> On 14/12/15 16:46, Mark Rutland wrote:
>>> On Mon, Dec 14, 2015 at 08:31:40AM -0800, Soren Brinkmann wrote:
>>>> Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
>>>> ---
>>>>  arch/arm64/boot/dts/xilinx/zynqmp.dtsi | 6 +++---
>>>>  1 file changed, 3 insertions(+), 3 deletions(-)
>>>>
>>>> diff --git a/arch/arm64/boot/dts/xilinx/zynqmp.dtsi b/arch/arm64/boot/dts/xilinx/zynqmp.dtsi
>>>> index 857eda5c7217..b5d1facadf16 100644
>>>> --- a/arch/arm64/boot/dts/xilinx/zynqmp.dtsi
>>>> +++ b/arch/arm64/boot/dts/xilinx/zynqmp.dtsi
>>>> @@ -80,10 +80,10 @@
>>>>  		gic: interrupt-controller@f9010000 {
>>>>  			compatible = "arm,gic-400", "arm,cortex-a15-gic";
>>>>  			#interrupt-cells = <3>;
>>>> -			reg = <0x0 0xf9010000 0x10000>,
>>>> -			      <0x0 0xf902f000 0x2000>,
>>>> +			reg = <0x0 0xf9010000 0x1000>,
>>>> +			      <0x0 0xf9020000 0x20000>,
>>>>  			      <0x0 0xf9040000 0x20000>,
>>>> -			      <0x0 0xf906f000 0x2000>;
>>>> +			      <0x0 0xf9060000 0x20000>;
>>>
>>> I'm confused. These sizes don't look right for GIC-400. Is this a custom
>>> GIC?
>>
>> Probably an implementation that obey the SBSA requirement of aliasing
>> the first 4kB of the CPU interface on a 64kB page, and the second one on
>> the following 64kB page. See the APM system for an example of such a
>> thing. I'm more concerned about the GICH region (3rd one), which has no
>> reason to be bigger than 4kB.
> 
> Xilinx didn't publish the memory map yet (at least I didn't see it in the
> public docs), so, let me give some excerpts:
> 
> GICD:
> GICD_CTLR 	0xF9010000 	32 	rw 	0x00000000 	Distributor Control Register
> ...
> GICD_CIDR3 	0xF9010FFC 	32 	ro 	0x000000B1 	Component ID3 Register
> 
> GICC:
> GICC_CTLR 	0xF9020000 	32 	rw 	0x00000000 	CPU Interface Control Register
> ...
> GICC_DIR 	0xF9030000 	32 	wo 	x 	Deactivate Interrupt Register
> 
> GICH:
> GICH_HCR 	0xF9040000 	32 	rw 	0x00000000 	Hypervisor Control Register
> ...
> GICH_LR3_Alias7 	0xF9050F0C 	32 	rw 	0x00000000 	List Register 3
> 
> GICV:
> GICV_CTLR 	0xF9060000 	32 	rw 	0x00000000 	Virtual Machine Control Register
> ...
> GICV_DIR 	0xF9070000 	32 	wo 	x 	VM Deactivate Interrupt Register
> 
> 
> Regarding the GICH area, it looks like it starts at 0xF9040000 and the
> alias blocks to access the other processor interfaces start at
> 0xF9050000.
> 
>>
>>> Did this ever work wit hteh old offsets and sizes?
>>
>> It probably dies when trying to use EOImode==1.
> 
> Without knowing what parts we really exercise, yes, the system comes up
> fine so far, but I recently found Linux boot hanging on QEMU and it
> seemed to be related to time not progressing (fast enough).
> I found a different DT using the values proposed here and that fixed the
> hang for me.

We have discussed this here before with Rob
https://lkml.org/lkml/2015/2/24/371

Not sure if there is any fix. It is probably just broken QEMU not DTS
description in mainline.

Thanks,
Michal