Subject: Re: [PATCH v2 4/4] pci: Use QEMU created PCI device nodes

From: Nikunj A Dadhania <[email-masked]>
Date: Mon, 27 Apr 2015 15:26:00 +0530

Thomas Huth <[email-masked]> writes:

> On Mon, 27 Apr 2015 13:32:33 +0530
> Nikunj A Dadhania <[email-masked]> wrote:
>
>> PCI Enumeration has been part of SLOF. Now with hotplug code addition
>> in QEMU, it makes more sense to have this code in one place,
>> i.e. QEMU.
>> 
>> Adding routines to walk through the device nodes created by QEMU. SLOF
>> will now configure the device/bridges and program the BARs for
>> communicating with the devices.
>> 
>> Signed-off-by: Nikunj A Dadhania <[email-masked]>
>> ---
>>  board-qemu/slof/pci-phb.fs | 44 +++++++++++++++++++++++++++++++++++++++++++-
>>  slof/fs/pci-properties.fs  |  6 +++++-
>>  2 files changed, 48 insertions(+), 2 deletions(-)
>> 
>> diff --git a/board-qemu/slof/pci-phb.fs b/board-qemu/slof/pci-phb.fs
>> index 529772f..a8fb7ca 100644
>> --- a/board-qemu/slof/pci-phb.fs
>> +++ b/board-qemu/slof/pci-phb.fs
>> @@ -282,6 +282,41 @@ setup-puid
>>     THEN
>>  ;
>>  
>> +: phb-pci-walk-bridge ( -- )
>> +    phb-debug? IF ."   Calling pci-walk-bridge " pwd cr THEN
>> +
>> +    get-node child ?dup 0= IF EXIT THEN    \ get and check if we have children
>> +    0 to pci-device-slots                  \ reset slot array to unpoppulated
>> +    BEGIN
>> +        dup                                \ Continue as long as there are children
>> +    WHILE
>> +        dup set-node                       \ Set child node as current node
>> +        my-space pci-set-slot              \ set the slot bit
>> +        my-space pci-htype@                \ read HEADER-Type
>> +        7f and                             \ Mask bit 7 - multifunction device
>> +        CASE
>> +            0 OF my-space pci-device-setup ENDOF  \ | set up the device
>> +            1 OF my-space pci-bridge-setup ENDOF  \ | set up the bridge
>> +            dup OF my-space pci-htype@ pci-out ENDOF
>> +        ENDCASE
>> +        peer
>> +    REPEAT drop
>> +    get-parent set-node
>> +;
>> +
>> +\ Landing routing to probe the popuated device tree
>> +: phb-pci-probe-bus ( busnr -- )
>> +    drop phb-pci-walk-bridge
>> +;
>> +
>> +\ Stub routine, as qemu has enumerated, we already have the device
>> +\ properties set.
>> +: phb-pci-device-props ( addr -- )
>> +    dup pci-class-name device-name
>> +    dup pci-device-assigned-addresses-prop
>> +    drop
>> +;
>> +
>>  \ Scan the child nodes of the pci root node to assign bars, fixup
>>  \ properties etc.
>>  : phb-setup-children
>> @@ -289,7 +324,14 @@ setup-puid
>>     my-puid TO puid                  \ Set current puid
>>     phb-parse-ranges
>>     1 TO pci-hotplug-enabled
>> -   1 0 (probe-pci-host-bridge)
>> +   s" qemu,phb-enumerated" get-node get-property 0<> IF
>
> I think you could simply omit the "0<>" in the above line (get-property
> returns TRUE if the property has not been found and FALSE if it has
> been found, so the topmost stack item is already suitable for the IF
> statement)

I find the usage of get-property a bit odd, as it returns TRUE when it
is not found. So have put " != 0"  as the condition, which I felt as more
intuitive.

If you don't feel strongly about it, I will like to have it this way.

>> +       1 0 (probe-pci-host-bridge)
>> +   ELSE
>> +       2drop
>> +       ['] phb-pci-probe-bus TO func-pci-probe-bus
>> +       ['] phb-pci-device-props TO func-pci-device-props
>> +       phb-pci-walk-bridge          \ PHB device tree is already populated.
>> +   THEN
>>     r> TO puid                       \ Restore previous puid
>>  ;
>>  phb-setup-children
>> diff --git a/slof/fs/pci-properties.fs b/slof/fs/pci-properties.fs
>> index 9efa87e..4f13402 100644
>> --- a/slof/fs/pci-properties.fs
>> +++ b/slof/fs/pci-properties.fs
>> @@ -651,6 +651,8 @@
>>          r> TO pci-device-slots          \ and reset the slot array
>>  ;
>>  
>> +DEFER func-pci-device-props
>> +
>>  \ used for an gerneric device set up
>>  \ if a device has no special handling for setup
>>  \ the device file (pci-device_VENDOR_DEVICE.fs) can call
>> @@ -659,6 +661,8 @@
>>          dup assign-all-device-bars      \ calc all BARs
>>          dup pci-set-irq-line            \ set the interrupt pin
>>          dup pci-set-capabilities        \ set up the capabilities
>> -        dup pci-device-props            \ and generate all properties
>> +        dup func-pci-device-props       \ and generate all properties
>>          drop                            \ forget the config-addr
>>  ;
>> +
>> +' pci-device-props TO func-pci-device-props
>
> Apart from the minor nit, looks fine to me now.
>
> Reviewed-by: Thomas Huth <[email-masked]>

Thanks,
Nikunj