> -----Original Message----- > From: Kishon Vijay Abraham I <[email protected]> > Sent: 2019年8月16日 18:50 > To: Xiaowei Bao <[email protected]>; Andrew Murray > <[email protected]> > Cc: [email protected]; [email protected]; > [email protected]; [email protected]; [email protected]; > [email protected]; Leo Li <[email protected]>; > [email protected]; [email protected]; [email protected]; > M.h. Lian <[email protected]>; Mingkai Hu <[email protected]>; > [email protected]; [email protected]; > [email protected]; [email protected]; > [email protected]; Z.q. Hou <[email protected]> > Subject: Re: [PATCH 02/10] PCI: designware-ep: Add the doorbell mode of > MSI-X in EP mode > > Hi, > > On 16/08/19 8:28 AM, Xiaowei Bao wrote: > > > > > >> -----Original Message----- > >> From: Andrew Murray <[email protected]> > >> Sent: 2019年8月15日 19:54 > >> To: Xiaowei Bao <[email protected]> > >> Cc: [email protected]; [email protected]; > >> [email protected]; [email protected]; [email protected]; > >> [email protected]; Leo Li <[email protected]>; [email protected]; > >> [email protected]; [email protected]; [email protected]; > >> M.h. Lian <[email protected]>; Mingkai Hu > <[email protected]>; > >> Roy Zang <[email protected]>; [email protected]; > >> [email protected]; [email protected]; > >> [email protected]; [email protected] > >> Subject: Re: [PATCH 02/10] PCI: designware-ep: Add the doorbell mode > >> of MSI-X in EP mode > >> > >> On Thu, Aug 15, 2019 at 04:37:08PM +0800, Xiaowei Bao wrote: > >>> Add the doorbell mode of MSI-X in EP mode. > >>> > >>> Signed-off-by: Xiaowei Bao <[email protected]> > >>> --- > >>> drivers/pci/controller/dwc/pcie-designware-ep.c | 14 > ++++++++++++++ > >>> drivers/pci/controller/dwc/pcie-designware.h | 14 > ++++++++++++++ > >>> 2 files changed, 28 insertions(+) > >>> > >>> diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c > >>> b/drivers/pci/controller/dwc/pcie-designware-ep.c > >>> index 75e2955..e3a7cdf 100644 > >>> --- a/drivers/pci/controller/dwc/pcie-designware-ep.c > >>> +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c > >>> @@ -454,6 +454,20 @@ 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, > >>> + 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) > >> > >> Have I understood correctly that the hardware provides an alternative > >> mechanism that allows for raising MSI-X interrupts without the bother > >> of reading the capabilities registers? > > Yes, the hardware provide two way to MSI-X, please check the page 492 > > of > > DWC_pcie_dm_registers_4.30 Menu. > > MSIX_DOORBELL_OFF on page 492 0x948 Description: MSI-X Doorbell > > Register....> > >> > >> If so is there any good reason to keep dw_pcie_ep_raise_msix_irq? > >> (And thus use it in dw_plat_pcie_ep_raise_irq also)? > > I am not sure, but I think the dw_pcie_ep_raise_msix_irq function is > > not correct, because I think we can't get the MSIX table from the > > address ep->phys_base + tbl_addr, but I also don't know where I can get the > correct MSIX table. > > Sometime back when I tried raising MSI-X from EP, it was failing. It's quite > possible dw_pcie_ep_raise_msix_irq function is not correct. > > MSI-X table can be obtained from the inbound ATU corresponding to the MSIX > bar. > IMO MSI-X support in EP mode needs rework. For instance set_msix should > also take BAR number as input to be configured in the MSI-X capability. The > function driver (pci-epf-test.c) should allocate memory taking into account > the > MSI-X table. Hi Kishon,
Thanks a lot for your explain, yes, we can get the MSI-X table from the inbound ATU of the MSIX BAR. > > Thanks > Kishon
