Re: [RFC PATCH 00/11] Refactor MSI to support Non-PCI device

[Yijing Wang <wangyijing@huawei.com>]

>>> We in Freescale will be using MSI for the devices behind a new-bus (which is
>> not PCI based), We have a separate bus driver for same. And this new bus driver
>> register/provide its own address/data write function which is based on that
>> specific bus protocol.
>>
>> Hi Bharat, I'm glad to know your MSI device working mode.
>> Provide the private MSI setup functions in bus-driver layer can't apply to all
>> Non-PCI MSI devices, because we can not guarantee Non-PCI MSI devices are always
>> on a bus. The existing HPET, DMAR device both have no bus bind.
> 
> Yes, that's why I was not sure of bus-driver or device-driver model.
> 
>> I'm working on a
>> new MSI setup framework, as you mentioned before, in device-driver model.
>>
>> I abstracted a new virtual device (called struct msi_dev), this msi_dev will
>> manage all MSI info,
> 
> Will this "struct msi_dev" will be part of "struct device"?

struct msi_dev contains the struct device

piece code:

struct msi_dev {
    u8 type;
    u8 enabled;
    u8 nvec;
    u8 nvec_retry;
    char *id;
    void __iomem *base;
    struct msix_entry *entries;
    struct list_head msi_list;
    struct device dev;
    void *msi_data;
    struct msi_driver *driver;
    const struct attribute_group **irq_groups;
};


struct msi_driver {
    const char *name;
    char *id;
    void (*msi_set_enable)(struct msi_dev *dev, int enable);
    int (*msi_setup_entry)(struct msi_dev *dev, struct msi_desc *entry);
    int (*msix_setup_entries)(struct msi_dev *dev, struct msi_desc *entry, int index);
    u32 (*msi_mask_irq)(struct msi_desc *desc, u32 mask, u32 flag);
    u32 (*msix_mask_irq)(struct msi_desc *desc, u32 flag);
    void (*msi_read_message)(struct msi_desc *desc, struct msi_msg *msg);
    void (*msi_write_message)(struct msi_desc *desc, struct msi_msg *msg);
    void (*msi_set_legacy_irq)(struct msi_dev *dev, int enable);
    struct device_driver driver;
};

Thanks!
Yijing.

> 
>> and a new bus named msi_bus, also introduced a new driver
>> msi_driver, msi_bus is responsible for binding msi_dev and msi_driver.
>> All MSI devices will be classified into different MSI device types, like
>> MSI_TYPE_PCI, MSI_TYPE_HPET, MSI_TYPE_DMAR, etc..
>>
>> Each MSI type device should provide a private struct msi_driver. msi_driver
>> should contain the type specific MSI ops functions to help setup and enable MSI
>> device, request MSI irq.
>>
>> I almost finish the first draft, and will post out next week in plan :)
> 
> Will be looking forward to next version.
> 
> Thanks
> -Bharat
> 
>>
>>
>> Thanks!
>> Yijing.
>>
>>>
>>> Thanks
>>> -Bharat
>>>
>>>>
>>>> My patchset is just a RFC draft, I will update it later, all we want
>>>> to do is make kernel support Non-PCI MSI devices.
>>>>
>>>> Thanks!
>>>> Yijing.
>>>>
>>>>
>>>>>
>>>>> Thanks
>>>>> Arnab
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>>>>>
>>>>
>>>>
>>>> --
>>>> Thanks!
>>>> Yijing
>>>>
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>>> .
>>>
>>
>>
>> --
>> Thanks!
>> Yijing
>>
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-- 
Thanks!
Yijing