RE: [PATCHv7 02/12] PCI: designware-ep: Add the doorbell mode of MSI-X in EP mode

["Z.q. Hou" <zhiqiang.hou@nxp.com>]

Hi Rob,

Thanks a lot for your comments!

> -----Original Message-----
> From: Rob Herring <robh@kernel.org>
> Sent: 2020年9月11日 1:58
> To: Z.q. Hou <zhiqiang.hou@nxp.com>
> Cc: linux-pci@vger.kernel.org; devicetree@vger.kernel.org;
> linux-kernel@vger.kernel.org; linux-arm-kernel@lists.infradead.org;
> linuxppc-dev@lists.ozlabs.org; bhelgaas@google.com;
> lorenzo.pieralisi@arm.com; shawnguo@kernel.org; Leo Li
> <leoyang.li@nxp.com>; kishon@ti.com; gustavo.pimentel@synopsys.com;
> Roy Zang <roy.zang@nxp.com>; jingoohan1@gmail.com;
> andrew.murray@arm.com; Mingkai Hu <mingkai.hu@nxp.com>; M.h. Lian
> <minghuan.lian@nxp.com>; Xiaowei Bao <xiaowei.bao@nxp.com>
> Subject: Re: [PATCHv7 02/12] PCI: designware-ep: Add the doorbell mode of
> MSI-X in EP mode
> 
> On Tue, Aug 11, 2020 at 05:54:31PM +0800, Zhiqiang Hou wrote:
> > From: Xiaowei Bao <xiaowei.bao@nxp.com>
> >
> > Add the doorbell mode of MSI-X in DWC EP driver.
> >
> > Signed-off-by: Xiaowei Bao <xiaowei.bao@nxp.com>
> > Reviewed-by: Andrew Murray <andrew.murray@arm.com>
> > Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
> > ---
> > V7:
> >  - Rebase the patch without functionality change.
> >
> >  drivers/pci/controller/dwc/pcie-designware-ep.c | 14 ++++++++++++++
> >  drivers/pci/controller/dwc/pcie-designware.h    | 12 ++++++++++++
> >  2 files changed, 26 insertions(+)
> >
> > diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c
> > b/drivers/pci/controller/dwc/pcie-designware-ep.c
> > index e5bd3a5ef380..e76b504ed465 100644
> > --- a/drivers/pci/controller/dwc/pcie-designware-ep.c
> > +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
> > @@ -471,6 +471,20 @@ int dw_pcie_ep_raise_msi_irq(struct dw_pcie_ep
> *ep, u8 func_no,
> >  	return 0;
> >  }
> >
> > +int dw_pcie_ep_raise_msix_irq_doorbell(struct dw_pcie_ep *ep, u8
> > +func_no,
> 
> return void. It never has an error.
> 
> It could also just be an inline function.

Yes, make sense and will change in next version.

Thanks,
Zhiqiang

> 
> > +				       u16 interrupt_num)
> > +{
> > +	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
> > +	u32 msg_data;
> > +
> > +	msg_data = (func_no << PCIE_MSIX_DOORBELL_PF_SHIFT) |
> > +		   (interrupt_num - 1);
> > +
> > +	dw_pcie_writel_dbi(pci, PCIE_MSIX_DOORBELL, msg_data);
> > +
> > +	return 0;
> > +}
> > +
> >  int dw_pcie_ep_raise_msix_irq(struct dw_pcie_ep *ep, u8 func_no,
> >  			      u16 interrupt_num)
> >  {
> > diff --git a/drivers/pci/controller/dwc/pcie-designware.h
> > b/drivers/pci/controller/dwc/pcie-designware.h
> > index 89f8271ec5ee..745b4938225a 100644
> > --- a/drivers/pci/controller/dwc/pcie-designware.h
> > +++ b/drivers/pci/controller/dwc/pcie-designware.h
> > @@ -97,6 +97,9 @@
> >  #define PCIE_MISC_CONTROL_1_OFF		0x8BC
> >  #define PCIE_DBI_RO_WR_EN		BIT(0)
> >
> > +#define PCIE_MSIX_DOORBELL		0x948
> > +#define PCIE_MSIX_DOORBELL_PF_SHIFT	24
> > +
> >  #define PCIE_PL_CHK_REG_CONTROL_STATUS			0xB20
> >  #define PCIE_PL_CHK_REG_CHK_REG_START			BIT(0)
> >  #define PCIE_PL_CHK_REG_CHK_REG_CONTINUOUS		BIT(1)
> > @@ -434,6 +437,8 @@ int dw_pcie_ep_raise_msi_irq(struct dw_pcie_ep
> *ep, u8 func_no,
> >  			     u8 interrupt_num);
> >  int dw_pcie_ep_raise_msix_irq(struct dw_pcie_ep *ep, u8 func_no,
> >  			     u16 interrupt_num);
> > +int dw_pcie_ep_raise_msix_irq_doorbell(struct dw_pcie_ep *ep, u8
> func_no,
> > +				       u16 interrupt_num);
> >  void dw_pcie_ep_reset_bar(struct dw_pcie *pci, enum pci_barno bar);
> > #else  static inline void dw_pcie_ep_linkup(struct dw_pcie_ep *ep) @@
> > -475,6 +480,13 @@ static inline int dw_pcie_ep_raise_msix_irq(struct
> dw_pcie_ep *ep, u8 func_no,
> >  	return 0;
> >  }
> >
> > +static inline int dw_pcie_ep_raise_msix_irq_doorbell(struct dw_pcie_ep
> *ep,
> > +						     u8 func_no,
> > +						     u16 interrupt_num)
> > +{
> > +	return 0;
> > +}
> > +
> >  static inline void dw_pcie_ep_reset_bar(struct dw_pcie *pci, enum
> > pci_barno bar)  {  }
> > --
> > 2.17.1
> >