[PATCH v11 0/6] PCI EP driver support MSI doorbell from host

[Marc Zyngier]

On Thu, 22 Sep 2022 12:12:40 -0400,
Frank Li <Frank.Li at nxp.com> wrote:
> 
> 
> 
>                   ┌───────┐          ┌──────────┐
>                   │       │          │          │
> ┌─────────────┐   │       │          │ PCI Host │
> │ MSI         │◄┐ │       │          │          │
> │ Controller  │ │ │       │          │          │
> └─────────────┘ └─┼───────┼──────────┼─Bar0     │
>                   │ PCI   │          │ Bar1     │
>                   │ Func  │          │ Bar2     │
>                   │       │          │ Bar3     │
>                   │       │          │ Bar4     │
>                   │       ├─────────►│          │
>                   └───────┘          └──────────┘
> 
> Many PCI controllers provided Endpoint functions.
> Generally PCI endpoint is hardware, which is not running a rich OS,
> like linux.
> 
> But Linux also supports endpoint functions.  PCI Host write BAR<n> space
> like write to memory. The EP side can't know memory changed by the Host
> driver. 
> 
> PCI Spec has not defined a standard method to do that.  Only define
> MSI(x) to let EP notified RC status change. 

[...]

FWIW, I have queued the first 4 patches of this series into -next. If
there is a need for these patches to be pulled by another subsystem, I
have pushed out a stable branch at [1].

Thanks,

	M.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git/log/?h=irq/fsl-mu-msi

-- 
Without deviation from the norm, progress is not possible.