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

From: [email-masked] (Zhou Wang)
Date: Thu, 28 May 2015 19:48:37 +0800

On 2015/5/28 3:51, Arnd Bergmann wrote:
> On Wednesday 27 May 2015 18:19:57 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.
>>
> 
> Awesome. Now we just need to find a way to move the align_resource callback.
> I wonder if the approach below would be acceptable.
> 
> 	Arnd
> 

Hi Arnd,

Many thanks for your kindly suggestions.

> diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c
> index fcbbbb1b9e95..20839d26a490 100644
> --- a/arch/arm/kernel/bios32.c
> +++ b/arch/arm/kernel/bios32.c
> @@ -597,9 +588,6 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res,
>  
>  	start = (start + align - 1) & ~(align - 1);
>  
> -	if (sys->align_resource)
> -		return sys->align_resource(dev, res, start, size, align);
> -
>  	return start;
>  }
>  
> diff --git a/drivers/pci/host/pci-mvebu.c b/drivers/pci/host/pci-mvebu.c
> index 1ab863551920..74216c9c2822 100644
> --- a/drivers/pci/host/pci-mvebu.c
> +++ b/drivers/pci/host/pci-mvebu.c
> @@ -751,27 +751,20 @@ static int mvebu_pcie_setup(int nr, struct pci_sys_data *sys)
>  	return 1;
>  }
>  
> -static struct pci_bus *mvebu_pcie_scan_bus(int nr, struct pci_sys_data *sys)
> +static resource_size_t mvebu_pcie_align_resource(void *data,
> +						 const struct resource *res,
> +						 resource_size_t size,
> +						 resource_size_t align)
>  {
> -	struct mvebu_pcie *pcie = sys_to_pcie(sys);
> -	struct pci_bus *bus;
> +	struct device *dev = data;
>  
> -	bus = pci_create_root_bus(&pcie->pdev->dev, sys->busnr,
> -				  &mvebu_pcie_ops, sys, &sys->resources);
> -	if (!bus)
> -		return NULL;
> +	resource_size_t start = res->start;
>  
> -	pci_scan_child_bus(bus);
> +	if (res->flags & IORESOURCE_IO && start & 0x300)
> +		start = (start + 0x3ff) & ~0x3ff;
>  
> -	return bus;
> -}
> +	start = (start + align - 1) & ~(align - 1);
>  
> -static resource_size_t mvebu_pcie_align_resource(struct pci_dev *dev,
> -						 const struct resource *res,
> -						 resource_size_t start,
> -						 resource_size_t size,
> -						 resource_size_t align)
> -{
>  	if (dev->bus->number != 0)
>  		return start;
>  
> @@ -796,6 +789,25 @@ static resource_size_t mvebu_pcie_align_resource(struct pci_dev *dev,
>  		return start;
>  }
>  
> +static struct pci_bus *mvebu_pcie_scan_bus(int nr, struct pci_sys_data *sys)
> +{
> +	struct mvebu_pcie *pcie = sys_to_pcie(sys);
> +	struct pci_host_bridge *phb;
> +	struct pci_bus *bus;
> +
> +	bus = pci_create_root_bus(&pcie->pdev->dev, sys->busnr,
> +				  &mvebu_pcie_ops, sys, &sys->resources);
> +	if (!bus)
> +		return NULL;
> +
> +	phb = pci_find_host_bridge(bus);
> +	phb->align_resource = mvebu_pcie_align_resource;
> +
> +	pci_scan_child_bus(bus);
> +
> +	return bus;
> +}
> +
>  static void mvebu_pcie_enable(struct mvebu_pcie *pcie)
>  {
>  	struct hw_pci hw;
> @@ -812,7 +824,6 @@ static void mvebu_pcie_enable(struct mvebu_pcie *pcie)
>  	hw.scan           = mvebu_pcie_scan_bus;
>  	hw.map_irq        = of_irq_parse_and_map_pci;
>  	hw.ops            = &mvebu_pcie_ops;
> -	hw.align_resource = mvebu_pcie_align_resource;
>  
>  	pci_common_init(&hw);
>  }
> diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c
> index 232f9254c11a..e1f5e13c4636 100644
> --- a/drivers/pci/setup-res.c
> +++ b/drivers/pci/setup-res.c
> @@ -200,7 +200,11 @@ static int pci_revert_fw_address(struct resource *res, struct pci_dev *dev,
>  }
>  
>  static int __pci_assign_resource(struct pci_bus *bus, struct pci_dev *dev,
> -		int resno, resource_size_t size, resource_size_t align)
> +		int resno, resource_size_t size, resource_size_t align,
> +		resource_size_t (*alignf)(void *,
> +					  const struct resource *,
> +					  resource_size_t,
> +					  resource_size_t))
>  {
>  	struct resource *res = dev->resource + resno;
>  	resource_size_t min;
> @@ -217,7 +221,7 @@ static int __pci_assign_resource(struct pci_bus *bus, struct pci_dev *dev,
>  	 */
>  	ret = pci_bus_alloc_resource(bus, res, size, align, min,
>  				     IORESOURCE_PREFETCH | IORESOURCE_MEM_64,
> -				     pcibios_align_resource, dev);
> +				     alignf, dev);
>  	if (ret == 0)
>  		return 0;
>  
> @@ -229,7 +233,7 @@ static int __pci_assign_resource(struct pci_bus *bus, struct pci_dev *dev,
>  	     (IORESOURCE_PREFETCH | IORESOURCE_MEM_64)) {
>  		ret = pci_bus_alloc_resource(bus, res, size, align, min,
>  					     IORESOURCE_PREFETCH,
> -					     pcibios_align_resource, dev);
> +					     alignf, dev);
>  		if (ret == 0)
>  			return 0;
>  	}
> @@ -242,7 +246,7 @@ static int __pci_assign_resource(struct pci_bus *bus, struct pci_dev *dev,
>  	 */
>  	if (res->flags & (IORESOURCE_PREFETCH | IORESOURCE_MEM_64))
>  		ret = pci_bus_alloc_resource(bus, res, size, align, min, 0,
> -					     pcibios_align_resource, dev);
> +					     alignf, dev);
>  
>  	return ret;
>  }
> @@ -251,10 +255,19 @@ static int _pci_assign_resource(struct pci_dev *dev, int resno,
>  				resource_size_t size, resource_size_t min_align)
>  {
>  	struct pci_bus *bus;
> +	struct pci_host_bridge *phb;
>  	int ret;
>  
>  	bus = dev->bus;
> -	while ((ret = __pci_assign_resource(bus, dev, resno, size, min_align))) {
> +	phb = pci_find_host_bridge(bus);
> +
> +	if (phb->align_resource)
> +		alignf = phb->align_resource;
> +	else
> +		alignf = pcibios_align_resource;
> +
> +	while ((ret = __pci_assign_resource(bus, dev, resno, size,
> +					    min_align, alignf))) {
>  		if (!bus->parent || !bus->self->transparent)
>  			break;
>  		bus = bus->parent;
> 

I think this code is fine, and we also should add a funtion point in struct pci_host_bridge to
store mvebu_pcie_align_resource. How about I make a new version patchset with above codes for
further reviewing ?

Best Regards,
Zhou

> .