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

> 
> .
> 


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