Subject: [RFC PATCH v1 1/3] PCI: designware: Add ARM64 support

From: [email-masked] (Zhou Wang)
Date: Thu, 28 May 2015 19:40:05 +0800

On 2015/5/28 0:19, Fabrice Gasnier wrote:
> On 05/27/2015 05:43 PM, Arnd Bergmann wrote:
>> On Wednesday 27 May 2015 17:31:46 Arnd Bergmann wrote:
>>> Yes, that works. However there are two problems with the approach:
>>>
>>> - we have to change all PCI host drivers on ARM to do this in order to remove
>>>    the ARM-specific pcibios_msi_controller() function
>>> - it's possible that there are dw_pcie implementations that do not include
>>>    an MSI controller, so that pointer would be NULL, which leads to the
>>>    core code to still call the ARM-specific pcibios_msi_controller() function
>>>    unless we remove it.
>> I wonder if this simple patch would be sufficient to kill off
>> pcibios_msi_controller().
>>
>> Can one of you try it?
>>
>>     Arnd
> 
> Hi Arnd,
> I tested it quickly on my platform, with and without CONFIG_PCI_MSI.
> In both case it seems to run fine with dw pcie.
>

Hi Fabrice,

Thanks for testing. But if you applied this patch, the code will not go into
pcibios_init_hw(), so it did not touch what Arnd modified.

Best Regards,
Zhou

>>
>> diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c
>> index fcbbbb1b9e95..7afb6d253162 100644
>> --- a/arch/arm/kernel/bios32.c
>> +++ b/arch/arm/kernel/bios32.c
>> @@ -18,15 +18,6 @@
>>     static int debug_pci;
>>   -#ifdef CONFIG_PCI_MSI
>> -struct msi_controller *pcibios_msi_controller(struct pci_dev *dev)
>> -{
>> -    struct pci_sys_data *sysdata = dev->bus->sysdata;
>> -
>> -    return sysdata->msi_ctrl;
>> -}
>> -#endif
>> -
>>   /*
>>    * We can't use pci_get_device() here since we are
>>    * called from interrupt context.
>> @@ -462,9 +453,6 @@ static void pcibios_init_hw(struct device *parent, struct hw_pci *hw,
>>           if (!sys)
>>               panic("PCI: unable to allocate sys data!");
>>   -#ifdef CONFIG_PCI_MSI
>> -        sys->msi_ctrl = hw->msi_ctrl;
>> -#endif
>>           sys->busnr   = busnr;
>>           sys->swizzle = hw->swizzle;
>>           sys->map_irq = hw->map_irq;
>> @@ -493,6 +481,9 @@ static void pcibios_init_hw(struct device *parent, struct hw_pci *hw,
>>                   panic("PCI: unable to scan bus!");
>>                 busnr = sys->bus->busn_res.end + 1;
>> +#ifdef CONFIG_PCI_MSI
>> +            bus->msi = hw->msi_ctrl;
> 
> (with small adaptation here: s/bus->msi/sys->bus->msi)
> 
> BR,
> Fabrice
>> +#endif
>>                 list_add(&sys->node, head);
>>           } else {
>>
> 
> 
> .
>