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

From: Thomas Huth <[email-masked]>
Date: Mon, 27 Apr 2015 10:38:16 +0200

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)

> +       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]>