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

["Sören Brinkmann" <soren.brinkmann@xilinx.com>]

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.

	Thanks,
	Sören