On Wed, Oct 15, 2014 at 04:06:52AM +0100, Yijing Wang wrote:
> Saving msi chip in pci_sys_data can make pci bus and
> devices don't need to know msi chip detail, it also
> make pci enumeration code be decoupled from msi chip.
> In fact, all pci devices under the same pci hostbridge
> share same msi chip. So msi chip should be seen as one
> of resources or attributes to be initialized in pci host
> bridge driver. Currently, pci hostbridge drivers create
> pci_host_bridge in pci_create_root_bus(), and pass arch
> specific pci sysdata to core pci scan functions. So pci
> arch sysdata is good place to save msi chip.
>
> Signed-off-by: Yijing Wang <wangyijing@xxxxxxxxxx>
> ---
> arch/arm/include/asm/mach/pci.h | 6 ++++++
> arch/arm/include/asm/pci.h | 9 +++++++++
> arch/arm/kernel/bios32.c | 3 +++
> drivers/pci/msi.c | 6 ++++++
> include/linux/pci.h | 9 +++++++++
> 5 files changed, 33 insertions(+), 0 deletions(-)
>
> diff --git a/arch/arm/include/asm/mach/pci.h b/arch/arm/include/asm/mach/pci.h
> index 7fc4278..59b0d87 100644
> --- a/arch/arm/include/asm/mach/pci.h
> +++ b/arch/arm/include/asm/mach/pci.h
> @@ -22,6 +22,9 @@ struct hw_pci {
> #ifdef CONFIG_PCI_DOMAINS
> int domain;
> #endif
> +#ifdef CONFIG_PCI_MSI
> + struct msi_chip *msi_chip;
> +#endif
> struct pci_ops *ops;
> int nr_controllers;
> void **private_data;
> @@ -47,6 +50,9 @@ struct pci_sys_data {
> #ifdef CONFIG_PCI_DOMAINS
> int domain;
> #endif
> +#ifdef CONFIG_PCI_MSI
> + struct msi_chip *msi_chip;
> +#endif
This struct is defined for ARM only. We are trying to remove dependency on it
so that we can have a single driver for ARM32 and ARM64 systems without
pcibios dependency. Why can't we add this msi chip data to the host
bridge struct instead ? I understand it is all a matter of how to pass
the pointer to pci_scan_root_bus(), where the bridge is created.
We could initialize the msi chip on the bridge through the bus pointer
returned by the pci_scan_root_bus() function.
Thanks,
Lorenzo
> struct list_head node;
> int busnr; /* primary bus number */
> u64 mem_offset; /* bus->cpu memory mapping offset */
> diff --git a/arch/arm/include/asm/pci.h b/arch/arm/include/asm/pci.h
> index 7e95d85..b562c09 100644
> --- a/arch/arm/include/asm/pci.h
> +++ b/arch/arm/include/asm/pci.h
> @@ -31,6 +31,15 @@ static inline int pci_proc_domain(struct pci_bus *bus)
> }
> #endif /* CONFIG_PCI_DOMAINS */
>
> +#ifdef CONFIG_PCI_MSI
> +static inline struct msi_chip *pci_msi_chip(struct pci_bus *bus)
> +{
> + struct pci_sys_data *root = bus->sysdata;
> +
> + return root->msi_chip;
> +}
> +#endif
> +
> /*
> * The PCI address space does equal the physical memory address space.
> * The networking and block device layers use this boolean for bounce
> diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c
> index 17a26c1..a19038d 100644
> --- a/arch/arm/kernel/bios32.c
> +++ b/arch/arm/kernel/bios32.c
> @@ -471,6 +471,9 @@ static void pcibios_init_hw(struct device *parent, struct hw_pci *hw,
> #ifdef CONFIG_PCI_DOMAINS
> sys->domain = hw->domain;
> #endif
> +#ifdef CONFIG_PCI_MSI
> + sys->msi_chip = hw->msi_chip;
> +#endif
> sys->busnr = busnr;
> sys->swizzle = hw->swizzle;
> sys->map_irq = hw->map_irq;
> diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
> index 22e413c..f11108c 100644
> --- a/drivers/pci/msi.c
> +++ b/drivers/pci/msi.c
> @@ -35,6 +35,9 @@ int __weak arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc)
> struct msi_chip *chip = dev->bus->msi;
> int err;
>
> + if (!chip)
> + chip = pci_msi_chip(dev->bus);
> +
> if (!chip || !chip->setup_irq)
> return -EINVAL;
>
> @@ -50,6 +53,9 @@ void __weak arch_teardown_msi_irq(unsigned int irq)
> struct msi_desc *entry = irq_get_msi_desc(irq);
> struct msi_chip *chip = entry->dev->bus->msi;
>
> + if (!chip)
> + chip = pci_msi_chip(entry->dev->bus);
> +
> if (!chip || !chip->teardown_irq)
> return;
>
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 9cd2721..7a48b40 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -1433,6 +1433,15 @@ static inline int pci_get_new_domain_nr(void) { return -ENOSYS; }
>
> #include <asm/pci.h>
>
> +/* Just avoid compile error, will be clean up later */
> +#ifdef CONFIG_PCI_MSI
> +
> +#ifndef pci_msi_chip
> +#define pci_msi_chip(bus) NULL
> +#endif
> +
> +#endif
> +
> /* these helpers provide future and backwards compatibility
> * for accessing popular PCI BAR info */
> #define pci_resource_start(dev, bar) ((dev)->resource[(bar)].start)
> --
> 1.7.1
>
> --
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