Re: [RFC 2/4] PCI: generic: Add support for ARM64 and MSI(x)

[Liviu Dudau]

On Wed, Oct 22, 2014 at 09:52:19PM +0100, Arnd Bergmann wrote:
> On Wednesday 22 October 2014 16:59:14 Lorenzo Pieralisi wrote:
> > On Wed, Oct 01, 2014 at 10:38:45AM +0100, Arnd Bergmann wrote:
> > 
> > [...]
> > 
> > > The arm32 implementations of pci_domain_nr/pci_proc_domain can probably be
> > > removed if we change the arm32 pcibios_init_hw function to call the new
> > > interfaces that set the domain number.
> > 
> > I wished, but it is a bit more complicated than I thought unfortunately,
> > mostly because some drivers, eg cns3xxx set the domain numbers
> > statically in pci_sys_data and this sets a chain of dependency that is
> > not easy to untangle. I think cns3xxx is the only legacy driver that "uses"
> > the domain number (in pci_sys_data) in a way that clashes with the
> > generic domain_nr implementation, I need to give it more thought.
> 
> Just had a look at that driver, shouldn't be too hard to change, see below.

I like this!

One thing though ...

> 
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> 
> diff --git a/arch/arm/mach-cns3xxx/pcie.c b/arch/arm/mach-cns3xxx/pcie.c
> index 45d6bd09e6ef..aa4b9d7c52fd 100644
> --- a/arch/arm/mach-cns3xxx/pcie.c
> +++ b/arch/arm/mach-cns3xxx/pcie.c
> @@ -30,18 +30,15 @@ struct cns3xxx_pcie {
>  	unsigned int irqs[2];
>  	struct resource res_io;
>  	struct resource res_mem;
> -	struct hw_pci hw_pci;
> -
> +	int port;
>  	bool linked;
>  };
>  
> -static struct cns3xxx_pcie cns3xxx_pcie[]; /* forward decl. */
> -
>  static struct cns3xxx_pcie *sysdata_to_cnspci(void *sysdata)
>  {
>  	struct pci_sys_data *root = sysdata;
>  
> -	return &cns3xxx_pcie[root->domain];
> +	return root->private_data;
>  }
>  
>  static struct cns3xxx_pcie *pdev_to_cnspci(const struct pci_dev *dev)
> @@ -192,13 +189,7 @@ static struct cns3xxx_pcie cns3xxx_pcie[] = {
>  			.flags = IORESOURCE_MEM,
>  		},
>  		.irqs = { IRQ_CNS3XXX_PCIE0_RC, IRQ_CNS3XXX_PCIE0_DEVICE, },
> -		.hw_pci = {
> -			.domain = 0,
> -			.nr_controllers = 1,
> -			.ops = &cns3xxx_pcie_ops,
> -			.setup = cns3xxx_pci_setup,
> -			.map_irq = cns3xxx_pcie_map_irq,
> -		},
> +		.port = 0,
>  	},
>  	[1] = {
>  		.host_regs = (void __iomem *)CNS3XXX_PCIE1_HOST_BASE_VIRT,
> @@ -217,19 +208,13 @@ static struct cns3xxx_pcie cns3xxx_pcie[] = {
>  			.flags = IORESOURCE_MEM,
>  		},
>  		.irqs = { IRQ_CNS3XXX_PCIE1_RC, IRQ_CNS3XXX_PCIE1_DEVICE, },
> -		.hw_pci = {
> -			.domain = 1,
> -			.nr_controllers = 1,
> -			.ops = &cns3xxx_pcie_ops,
> -			.setup = cns3xxx_pci_setup,
> -			.map_irq = cns3xxx_pcie_map_irq,
> -		},
> +		.port = 1,
>  	},
>  };
>  
>  static void __init cns3xxx_pcie_check_link(struct cns3xxx_pcie *cnspci)
>  {
> -	int port = cnspci->hw_pci.domain;
> +	int port = cnspci->port;
>  	u32 reg;
>  	unsigned long time;
>  
> @@ -260,9 +245,10 @@ static void __init cns3xxx_pcie_check_link(struct cns3xxx_pcie *cnspci)
>  
>  static void __init cns3xxx_pcie_hw_init(struct cns3xxx_pcie *cnspci)
>  {
> -	int port = cnspci->hw_pci.domain;
> +	int port = cnspci->port;
>  	struct pci_sys_data sd = {
>  		.domain = port,
> +		.private_data = cnspci,
>  	};
>  	struct pci_bus bus = {
>  		.number = 0,
> @@ -323,6 +309,14 @@ static int cns3xxx_pcie_abort_handler(unsigned long addr, unsigned int fsr,
>  void __init cns3xxx_pcie_init_late(void)
>  {
>  	int i;
> +	void *private_data;
> +	struct hw_pci hw_pci = {
> +		.nr_controllers = 1,
> +		.ops = &cns3xxx_pcie_ops,
> +		.setup = cns3xxx_pci_setup,
> +		.map_irq = cns3xxx_pcie_map_irq,
> +		.private_data = &private_data,
> +	};
>  
>  	pcibios_min_io = 0;
>  	pcibios_min_mem = 0;
> @@ -335,7 +329,9 @@ void __init cns3xxx_pcie_init_late(void)
>  		cns3xxx_pwr_soft_rst(0x1 << PM_SOFT_RST_REG_OFFST_PCIE(i));
>  		cns3xxx_pcie_check_link(&cns3xxx_pcie[i]);
>  		cns3xxx_pcie_hw_init(&cns3xxx_pcie[i]);
> -		pci_common_init(&cns3xxx_pcie[i].hw_pci);
> +		hw_pci->domain = i;
> +		private_data = &cns3xxx_pcie[i];

Is this dance with pointers absolutely necessary? Does gcc though dishes at you
for doing hw_pci->private_data = &cns3xxx_pcie[i] directly?

Best regards,
Liviu

> +		pci_common_init(&hw_pci);
>  	}
>  
>  	pci_assign_unassigned_resources();
> 
> 
> 
> 

-- 
====================
| I would like to |
| fix the world,  |
| but they're not |
| giving me the   |
 \ source code!  /
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