[RFC] PCI: pcie-designware: allow drivers as loadable modules

[bhelgaas@google.com (Bjorn Helgaas)]

On Thu, Jul 24, 2014 at 11:17:45AM +0200, Arnd Bergmann wrote:
> From 0ee79c7451851a34e5a7c33eb6020befcdcb2b24 Mon Sep 17 00:00:00 2001
> From: Arnd Bergmann <arnd@arndb.de>
> Date: Thu, 24 Jul 2014 11:12:48 +0200
> Subject: [PATCH] PCI: pcie-designware: allow drivers as loadable modules
> 
> The new pcie-spear13xx driver uses the pcie-designware library
> and in the current form it can be built as a loadable module.
> However, the functions it uses from the base driver are not exported,
> so this results in a build failure and a module that can never
> be loaded:
> 
> ERROR: "dw_pcie_host_init" [drivers/pci/host/pcie-spear13xx.ko] undefined!
> ERROR: "dw_handle_msi_irq" [drivers/pci/host/pcie-spear13xx.ko] undefined!
> ERROR: "dw_pcie_msi_init" [drivers/pci/host/pcie-spear13xx.ko] undefined!
> ERROR: "dw_pcie_cfg_write" [drivers/pci/host/pcie-spear13xx.ko] undefined!
> ERROR: "dw_pcie_cfg_read" [drivers/pci/host/pcie-spear13xx.ko] undefined!
> ERROR: "dw_pcie_setup_rc" [drivers/pci/host/pcie-spear13xx.ko] undefined!
> ERROR: "dw_pcie_link_up" [drivers/pci/host/pcie-spear13xx.ko] undefined!
> 
> If we want to allow loadable pcie-designware drivers, we have to
> export all those symbols and ensure none of them are marked as __init.
> This also requires making pci_assign_unassigned_resources available
> after boot.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
> If we don't want this patch for some reason, we should instead mark
> this driver 'bool' in Kconfig, so it becomes impossible to encounter
> this build error.

I'm not opposed to doing this, but I applied Sachin's patch that changes
the Kconfig option to bool, so I'll drop this one for now.

> diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-designware.c
> index 1eaf4df3618a..0348408ebc68 100644
> --- a/drivers/pci/host/pcie-designware.c
> +++ b/drivers/pci/host/pcie-designware.c
> @@ -88,6 +88,7 @@ int dw_pcie_cfg_read(void __iomem *addr, int where, int size, u32 *val)
>  
>  	return PCIBIOS_SUCCESSFUL;
>  }
> +EXPORT_SYMBOL_GPL(dw_pcie_cfg_read);
>  
>  int dw_pcie_cfg_write(void __iomem *addr, int where, int size, u32 val)
>  {
> @@ -102,6 +103,7 @@ int dw_pcie_cfg_write(void __iomem *addr, int where, int size, u32 val)
>  
>  	return PCIBIOS_SUCCESSFUL;
>  }
> +EXPORT_SYMBOL_GPL(dw_pcie_cfg_write);
>  
>  static inline void dw_pcie_readl_rc(struct pcie_port *pp, u32 reg, u32 *val)
>  {
> @@ -182,6 +184,7 @@ irqreturn_t dw_handle_msi_irq(struct pcie_port *pp)
>  
>  	return ret;
>  }
> +EXPORT_SYMBOL_GPL(dw_handle_msi_irq);
>  
>  void dw_pcie_msi_init(struct pcie_port *pp)
>  {
> @@ -192,6 +195,7 @@ void dw_pcie_msi_init(struct pcie_port *pp)
>  			virt_to_phys((void *)pp->msi_data));
>  	dw_pcie_wr_own_conf(pp, PCIE_MSI_ADDR_HI, 4, 0);
>  }
> +EXPORT_SYMBOL_GPL(dw_pcie_msi_init);
>  
>  static int find_valid_pos0(struct pcie_port *pp, int msgvec, int pos, int *pos0)
>  {
> @@ -378,6 +382,7 @@ int dw_pcie_link_up(struct pcie_port *pp)
>  	else
>  		return 0;
>  }
> +EXPORT_SYMBOL_GPL(dw_pcie_link_up);
>  
>  static int dw_pcie_msi_map(struct irq_domain *domain, unsigned int irq,
>  			irq_hw_number_t hwirq)
> @@ -393,7 +398,7 @@ static const struct irq_domain_ops msi_domain_ops = {
>  	.map = dw_pcie_msi_map,
>  };
>  
> -int __init dw_pcie_host_init(struct pcie_port *pp)
> +int dw_pcie_host_init(struct pcie_port *pp)
>  {
>  	struct device_node *np = pp->dev->of_node;
>  	struct of_pci_range range;
> @@ -503,6 +508,7 @@ int __init dw_pcie_host_init(struct pcie_port *pp)
>  
>  	return 0;
>  }
> +EXPORT_SYMBOL_GPL(dw_pcie_host_init);
>  
>  static void dw_pcie_prog_viewport_cfg0(struct pcie_port *pp, u32 busdev)
>  {
> @@ -829,6 +835,7 @@ void dw_pcie_setup_rc(struct pcie_port *pp)
>  		PCI_COMMAND_MASTER | PCI_COMMAND_SERR;
>  	dw_pcie_writel_rc(pp, val, PCI_COMMAND);
>  }
> +EXPORT_SYMBOL_GPL(dw_pcie_setup_rc);
>  
>  MODULE_AUTHOR("Jingoo Han <jg1.han@samsung.com>");
>  MODULE_DESCRIPTION("Designware PCIe host controller driver");
> diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
> index 6373985ad3f7..eeef7a1f4d0d 100644
> --- a/drivers/pci/setup-bus.c
> +++ b/drivers/pci/setup-bus.c
> @@ -1634,7 +1634,7 @@ dump:
>  	pci_bus_dump_resources(bus);
>  }
>  
> -void __init pci_assign_unassigned_resources(void)
> +void pci_assign_unassigned_resources(void)
>  {
>  	struct pci_bus *root_bus;
>  
> 
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