Re: [Xen-devel] [GSOC-2019] Problem with initializing crossbar on bb-x15 in dom0

[Denis Obrezkov <denisobrezkov@xxxxxxxxx>]

Hi,

On 7/6/19 12:56 PM, Julien Grall wrote:
> Hi Denis,
> 
> On 7/6/19 11:19 AM, Denis Obrezkov wrote:
>> On 7/5/19 11:47 PM, Denis Obrezkov wrote:
>>> So,
>>>
>>>
>>>> I am going to try to expose the whole crossbar to the dom0 by
>>>> mapping it
>>>> into dom0 and after that to unmap it and restrict the use of the
>>>> control
>>>> register via register_mmio_handler. Don't know whether this will work.
>>>>
>>>
>>> I tried and write now now visible progress:
>>> --- a/xen/arch/arm/platforms/omap5.c
>>> +++ b/xen/arch/arm/platforms/omap5.c
>>> @@ -23,6 +23,8 @@
>>>   #include <xen/vmap.h>
>>>   #include <asm/io.h>
>>>
>>> +#define OMAP5_CTRL_CORE_MPU_IRQ 0x00000A48
>>> +
>>>   void omap5_init_secondary(void);
>>>   asm (
>>>           ".text                              \n\t"
>>> @@ -124,6 +126,8 @@ static int omap5_specific_mapping(struct domain *d)
>>>       map_mmio_regions(d, gaddr_to_gfn(OMAP5_SRAM_PA), 32,
>>>                        maddr_to_mfn(OMAP5_SRAM_PA));
>>>
>>> +    map_mmio_regions(d, gaddr_to_gfn(OMAP5_CTRL_CORE_MPU_IRQ), 300,
>>> +                    maddr_to_mfn(OMAP5_CTRL_CORE_MPU_IRQ));
>>>       return 0;
>>>   }
>>>
>>>
>> I can see there is a mistake in OMAP5_CTRL_CORE_MPU_IRQ address, so, I
>> tried the right address for the MPU crossbar cotrol registers and I also
>> tried to expose the whole control CTRL register but unsurprisingly
>> haven't succeeded.
>>
> 
> The crossbar is described in the Device-Tree, Xen should already map the
> crossbar in Dom0.
> 
> I wasn't able to find any clue in the log (from your first e-mail) that
> the crossbar is not mapped to Dom0. Actually, per the log, the mapping
> should have been done:
> 
> (XEN) handle /ocp/crossbar@4a002a48
> (XEN) dt_irq_number: dev=/ocp/crossbar@4a002a48
> (XEN) /ocp/crossbar@4a002a48 passthrough = 1 nirq = 0 naddr = 1
> (XEN) DT: ** translation for device /ocp/crossbar@4a002a48 **
> (XEN) DT: bus is default (na=1, ns=1) on /ocp
> (XEN) DT: translating address:<3> 4a002a48<3>
> (XEN) DT: parent bus is default (na=2, ns=2) on /
> (XEN) DT: walking ranges...
> (XEN) DT: default map, cp=0, s=c0000000, da=4a002a48
> (XEN) DT: parent translation for:<3> 00000000<3> 00000000<3>
> (XEN) DT: with offset: 4a002a48
> (XEN) DT: one level translation:<3> 00000000<3> 4a002a48<3>
> (XEN) DT: reached root node
> (XEN)   - MMIO: 004a002a48 - 004a002b78 P2MType=5
> (XEN) handle /ocp/dss@58000000
> (XEN) dt_irq_number: dev=/ocp/dss@58000000
> (XEN) /ocp/dss@58000000 passthrough = 1 nirq = 0 naddr = 5
> (XEN) DT: ** translation for device /ocp/dss@58000000 **
> 
> Looking towards the end of the log:
> 
> (XEN) traps.c:1998:d0v0 HSR=0x93800007 pc=0xc012bd5c gva=0xfa243404
> gpa=0x00000048243404
> 
> This means Linux is trying to access the address 0x00000048243404 which
> was not mapped in the stage-2. This does not seem to belong to the
> crossbar but PRCM_MPU. The function omap5_specific_mapping() should do
> the mapping for you. Is it called for your platform?
> 
> On a side note, I am not convinced exposing directly (i.e without
> emulation) the crossbar to dom0 will help us. Per the log, the UART will
> also use the crossbar:
> 
> (XEN) omap-uart: Unable to retrieve the IRQ
> (XEN) Unable to initialize dtuart: -22
> (XEN) Bad console= option 'dtuart'
> 
> So Xen needs to be able to control it. To make things easier, it would
> probably better to first focus on getting a small crossbar driver in Xen
> and verify you can use the UART in Xen (such as receiving characters).
> 
> Cheers,
> 
sorry for confusing you, I share a bit outdated log but only to show the
output of xen about device tree. We already overcome that error about
omap specific mapping (applied one of Iain's patches).

I tried to replicate the tegra version of legacy irq controller support
you mentioned in the irq:
https://github.com/embeddedden/xen/commit/180af7ffc8abbbc3ed41dcbc9abc6e8b12daa57a

Now, I have an error:
(XEN) *** LOADING DOMAIN 0 ***



(XEN) Loading d0 kernel from boot module @ 0000000082000000



(XEN) Loading ramdisk from boot module @ 0000000084000000



(XEN) Allocating 1:1 mappings totalling 512MB for dom0:



(XEN) BANK[0] 0x000000a0000000-0x000000c0000000 (512MB)



(XEN) Grant table range: 0x00000085000000-0x00000085040000



(XEN) Allocating PPI 16 for event channel interrupt



(XEN) Loading zImage from 0000000082000000 to
00000000a7c00000-00000000a7fdea20


(XEN)



(XEN) ****************************************



(XEN) Panic on CPU 0:



(XEN) Unable to copy the kernel in the hwdom memory



(XEN) ****************************************
Probably, I messed something with remapping.


-- 
Regards, Denis Obrezkov

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