On Mon, Aug 5, 2024 at 3:43 PM Serge Semin <fancer.lancer@xxxxxxxxx> wrote: > > On Fri, Aug 02, 2024 at 03:06:05PM -0700, Jitendra Vegiraju wrote: > > On Fri, Aug 2, 2024 at 3:02 AM Serge Semin <fancer.lancer@xxxxxxxxx> wrote: > > > > > > Hi Jitendra > > > > > > On Thu, Aug 01, 2024 at 08:18:19PM -0700, jitendra.vegiraju@xxxxxxxxxxxx wrote: > > > > From: Jitendra Vegiraju <jitendra.vegiraju@xxxxxxxxxxxx> > > > > > > > > This patchset adds basic PCI ethernet device driver support for Broadcom > > > > BCM8958x Automotive Ethernet switch SoC devices. > > > > > > > > This SoC device has PCIe ethernet MAC attached to an integrated ethernet > > > > switch using XGMII interface. The PCIe ethernet controller is presented to > > > > the Linux host as PCI network device. > > > > > > > > The following block diagram gives an overview of the application. > > > > +=================================+ > > > > | Host CPU/Linux | > > > > +=================================+ > > > > || PCIe > > > > || > > > > +==========================================+ > > > > | +--------------+ | > > > > | | PCIE Endpoint| | > > > > | | Ethernet | | > > > > | | Controller | | > > > > | | DMA | | > > > > | +--------------+ | > > > > | | MAC | BCM8958X | > > > > | +--------------+ SoC | > > > > | || XGMII | > > > > | || | > > > > | +--------------+ | > > > > | | Ethernet | | > > > > | | switch | | > > > > | +--------------+ | > > > > | || || || || | > > > > +==========================================+ > > > > || || || || More external interfaces > > > > > > > > The MAC block on BCM8958x is based on Synopsis XGMAC 4.00a core. This > > > > driver uses common dwxgmac2 code where applicable. > > > > > > Thanks for submitting the series. > > > > > > I am curious how come Broadcom got to use an IP-core which hasn't > > > been even announced by Synopsys. AFAICS the most modern DW XGMAC > > > IP-core is of v3.xxa version: > > > > > > https://www.synopsys.com/dw/ipdir.php?ds=dwc_ether_xgmac > > > > > > I am not sure why the 4.00a IP-code is not announced for general > > availability yet. > > The Synopsis documentation for this IP mentions 3.xx IP as reference > > for this design and lists > > new features for 4.00a. > > > > > Are you sure that your device isn't equipped with some another DW MAC > > > IP-core, like DW 25G Ethernet MAC? (which BTW is equipped with a new > > > Hyper DMA engine with a capability to have up to 128/256 channels with > > > likely indirect addressing.) Do I miss something? > > > > > Yes, I briefly mentioned the new DMA architecture in the commit log > > for patch 1/3. > > You are correct, the name for the new DMA engine is Hyper DMA. It > > probably started with some 3.xx IP-Core. > > This DW-MAC is capable of 25G, but this SOC is not using 25G support. > > Then what you have is likely the DW 25GMAC since just DW XGMAC hasn't > been announced to have neither 25G speed nor the Hyper-DMA with the > virtualization channels capabilities. Meanwhile the former IP-core > does have these features: > https://www.synopsys.com/dw/ipdir.php?ds=dwc_25g_ethernet_mac_ip > > Alas I don't have the DW 25GMAC IP-core databook to say for sure, but > that's the only explanation of why you have the 0x40 Synopsys ID and > the IP-core version of v4.00a, and the 25G capability of the MAC. > > Seeing Synopsys tends to re-use the CSRs mapping even across the major > IP-core releases it isn't that surprising that the DW XGMAC 3.xx > IP-core was referenced in the doc. (See the driver, DW XLGMAC is > almost fully compatible with the DW XGMAC CSRs mapping.) > > Moreover the most DMA-capable device currently supported by the > STMMAC-driver is DW XGMAC/XLGMAC and it can't have more than 16 > DMA-channels. That allows to directly map all the channels CSRs to the > system memory. But your case is different. The DW 25GMAC IP-core is > announced to support virtualization up to 128/256 channels, for which > the direct CSRs mapping could require 16-times more memory. That's > likely why the indirect addressing was implemented to access the > settings of all the possible channels. That's also implicitly proofs > that you have the DW 25GMAC IP-core. Hi Serge(y) Thanks for reviewing the patch series. Sorry for the delay in my response. We waited for a clarification on the IP version. Its confirmed that we got an early adapter version of 25GMAC IP-Core. Added more details in the context of other questions in Patch 1,2. > > -Serge(y) > > > > > > * I'll join the patch set review after the weekend, sometime on the > > > next week. > > > > > > -Serge(y) > > > > > > > Driver functionality specific to this MAC is implemented in dwxgmac4.c. > > > > Management of integrated ethernet switch on this SoC is not handled by > > > > the PCIe interface. > > > > This SoC device has PCIe ethernet MAC directly attached to an integrated > > > > ethernet switch using XGMII interface. > > > > > > > > v2->v3: > > > > Addressed v2 comments from Andrew, Jakub, Russel and Simon. > > > > Based on suggestion by Russel and Andrew, added software node to create > > > > phylink in fixed-link mode. > > > > Moved dwxgmac4 specific functions to new files dwxgmac4.c and dwxgmac4.h > > > > in stmmac core module. > > > > Reorganized the code to use the existing glue logic support for xgmac in > > > > hwif.c and override ops functions for dwxgmac4 specific functions. > > > > The patch is split into three parts. > > > > Patch#1 Adds dma_ops for dwxgmac4 in stmmac core > > > > Patch#2 Hooks in the hardware interface handling for dwxgmac4 > > > > Patch#3 Adds PCI driver for BCM8958x device > > > > > > > > v1->v2: > > > > Minor fixes to address coding style issues. > > > > Sent v2 too soon by mistake, without waiting for review comments. > > > > Received feedback on this version. > > > > https://lore.kernel.org/netdev/20240511015924.41457-1-jitendra.vegiraju@xxxxxxxxxxxx/ > > > > > > > > v1: > > > > https://lore.kernel.org/netdev/20240510000331.154486-1-jitendra.vegiraju@xxxxxxxxxxxx/ > > > > > > > > Jitendra Vegiraju (3): > > > > Add basic dwxgmac4 support to stmmac core > > > > Integrate dwxgmac4 into stmmac hwif handling > > > > Add PCI driver support for BCM8958x > > > > > > > > MAINTAINERS | 8 + > > > > drivers/net/ethernet/stmicro/stmmac/Kconfig | 11 + > > > > drivers/net/ethernet/stmicro/stmmac/Makefile | 3 +- > > > > drivers/net/ethernet/stmicro/stmmac/common.h | 4 + > > > > .../net/ethernet/stmicro/stmmac/dwmac-brcm.c | 517 ++++++++++++++++++ > > > > .../ethernet/stmicro/stmmac/dwxgmac2_dma.c | 31 ++ > > > > .../net/ethernet/stmicro/stmmac/dwxgmac4.c | 142 +++++ > > > > .../net/ethernet/stmicro/stmmac/dwxgmac4.h | 84 +++ > > > > drivers/net/ethernet/stmicro/stmmac/hwif.c | 26 +- > > > > drivers/net/ethernet/stmicro/stmmac/hwif.h | 1 + > > > > 10 files changed, 825 insertions(+), 2 deletions(-) > > > > create mode 100644 drivers/net/ethernet/stmicro/stmmac/dwmac-brcm.c > > > > create mode 100644 drivers/net/ethernet/stmicro/stmmac/dwxgmac4.c > > > > create mode 100644 drivers/net/ethernet/stmicro/stmmac/dwxgmac4.h > > > > > > > > -- > > > > 2.34.1 > > > > > > > >
