[U-Boot] [PATCH 7/7] pci/layerscape: set LUT and msi-map for discovered PCI devices

[Marc Zyngier]

On 23/02/16 15:01, Stuart Yoder wrote:
> 
> 
>> -----Original Message-----
>> From: Minghuan Lian
>> Sent: Tuesday, February 23, 2016 3:57 AM
>> To: Stuart Yoder <stuart.yoder at nxp.com>; u-boot at lists.denx.de
>> Cc: york sun <york.sun at nxp.com>; Prabhakar Kushwaha <prabhakar.kushwaha at nxp.com>;
>> Mingkai Hu <mingkai.hu at nxp.com>; Yang-Leo Li <leoyang.li at nxp.com>; marc.zyngier at arm.com;
>> Stuart Yoder <stuart.yoder at nxp.com>
>> Subject: RE: [PATCH 7/7] pci/layerscape: set LUT and msi-map for discovered PCI devices
>>
>> Hi Stuart,
>>
>>
>>> -----Original Message-----
>>> From: Stuart Yoder [mailto:stuart.yoder at nxp.com]
>>> Sent: Monday, February 22, 2016 11:26 PM
>>> To: u-boot at lists.denx.de
>>> Cc: york sun <york.sun at nxp.com>; Prabhakar Kushwaha
>>> <prabhakar.kushwaha at nxp.com>; Mingkai Hu <mingkai.hu at nxp.com>;
>>> Minghuan Lian <minghuan.lian at nxp.com>; Yang-Leo Li <leoyang.li at nxp.com>;
>>> marc.zyngier at arm.com; Stuart Yoder <stuart.yoder at nxp.com>
>>> Subject: [PATCH 7/7] pci/layerscape: set LUT and msi-map for discovered PCI
>>> devices
>>>
>>> From: Stuart Yoder <stuart.yoder at nxp.com>
>>>
>>> for all PCI devices discovered in a system:
>>>   -allocate a LUT (look-up-table) entry in that PCI controller
>>>   -allocate a stream ID for the device
>>>   -program and enable a LUT entry (maps PCI requester id to stream ID)
>>>   -set the msi-map property on the controller reflecting the
>>>    LUT mapping
>>>
>>> basic bus scanning loop/logic was taken from drivers/pci/pci.c
>>> pci_hose_scan_bus().
>>>
>>> Signed-off-by: Stuart Yoder <stuart.yoder at nxp.com>
>>> ---
>>>  drivers/pci/pcie_layerscape.c |   68
>>> +++++++++++++++++++++++++++++++++++++++++
>>>  1 file changed, 68 insertions(+)
>>>
>>> diff --git a/drivers/pci/pcie_layerscape.c b/drivers/pci/pcie_layerscape.c index
>>> dfafaf2..eaac9e1 100644
>>> --- a/drivers/pci/pcie_layerscape.c
>>> +++ b/drivers/pci/pcie_layerscape.c
>>> @@ -569,6 +569,70 @@ static void fdt_pcie_set_msi_map_entry(void *blob,
>>> struct ls_pcie *pcie,
>>>  	fdt_appendprop_u32(blob, nodeoffset, "msi-map", 1);  }
>>>
>>> +static void fdt_fixup_pcie(void *blob)
>>> +{
>>> +	unsigned int found_multi = 0;
>>> +	unsigned char header_type;
>>> +	int index;
>>> +	u32 streamid;
>>> +	pci_dev_t dev;
>>> +	int bus;
>>> +	unsigned short id;
>>> +	struct pci_controller *hose;
>>> +	struct ls_pcie *pcie;
>>> +	int i;
>>> +
>>> +	for (i = 0, hose = pci_get_hose_head(); hose; hose = hose->next, i++) {
>>> +		pcie = hose->priv_data;
>>> +		for (bus = hose->first_busno; bus <= hose->last_busno; bus++) {
>>> +
>>> +			for (dev =  PCI_BDF(bus, 0, 0);
>>> +			     dev <  PCI_BDF(bus, PCI_MAX_PCI_DEVICES - 1,
>>> +					    PCI_MAX_PCI_FUNCTIONS - 1);
>>> +			     dev += PCI_BDF(0, 0, 1)) {
>>> +
>>> +				/* skip the host bridge */
>>> +				if (dev == PCI_BDF(0, 0, 0))
>>> +					continue;
>> [Lian Minghuan-B31939] PCIe controller also needs a stream ID. It may request a MSI for
>> AER PME hotplug service.
> 
> Is this a theoretical problem, or does the ls2080a actually support
> hotplug and assert an MSI?  Mingkai said that a hotplug interrupt
> could be an INTx interrupt.  The fdt_fixup_pcie() in this patch
> is specifically for Layerscape SoCs and I think it makes sense
> to implement what hardware actually supports.

For sure, the ls2085 reports such a capability, and the kernel assigns a
pair of MSIs to it.

 97:          0          0          0          0          0          0
        0          0   ITS-MSI   0 Edge      PCIe PME
 98:          0          0          0          0          0          0
        0          0   ITS-MSI   1 Edge      aerdrv

I haven't tried to exercise it though.

	M.
-- 
Jazz is not dead. It just smells funny...