Re: [PATCH net-next v5 4/5] net: stmmac: Add PCI driver support for BCM8958x

From: Serge Semin
Date: Tue Sep 10 2024 - 15:52:22 EST


On Tue, Sep 03, 2024 at 10:48:14PM -0700, jitendra.vegiraju@xxxxxxxxxxxx wrote:
> From: Jitendra Vegiraju <jitendra.vegiraju@xxxxxxxxxxxx>
>
> Add PCI ethernet driver support for Broadcom BCM8958x SoC devices used
> in automotive applications.
>
> 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 IP block on BCM8958x is based on Synopsis XGMAC 4.00a core. This
> driver uses common dwxgmac2 code where applicable.
> Driver functionality specific to this MAC is implemented in dw25gmac.c.
> The glue driver is responsible for setting up hdma mappings.
>
> Management of integrated ethernet switch on this SoC is not handled by
> the PCIe interface.
> Since BCM8958x is an early adopter device, override the hardware reported
> synopsis versions with actual DW25MAC versions that support hdma.
>
> This SoC device has PCIe ethernet MAC directly attached to an integrated
> ethernet switch using XGMII interface. Since device tree support is not
> available on this platform, a software node is created to enable
> fixed-link support using phylink driver.
>
> Signed-off-by: Jitendra Vegiraju <jitendra.vegiraju@xxxxxxxxxxxx>
> ---
> .../net/ethernet/stmicro/stmmac/dwmac-brcm.c | 507 ++++++++++++++++++
> 1 file changed, 507 insertions(+)
> create mode 100644 drivers/net/ethernet/stmicro/stmmac/dwmac-brcm.c
>
> diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-brcm.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-brcm.c
> new file mode 100644
> index 000000000000..b5dd97d9b938
> --- /dev/null
> +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-brcm.c
> @@ -0,0 +1,507 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/* Copyright (c) 2024 Broadcom Corporation
> + *
> + * PCI driver for ethernet interface of BCM8958X automotive switch chip.
> + *
> + * High level block diagram of the device.
> + * +=================================+
> + * | Host CPU/Linux |
> + * +=================================+
> + * || PCIe
> + * ||
> + * +==========================================+
> + * | +--------------+ |
> + * | | PCIE Endpoint| |
> + * | | Ethernet | |
> + * | | Controller | |
> + * | | DMA | |
> + * | +--------------+ |
> + * | | MAC | BCM8958X |
> + * | +--------------+ SoC |
> + * | || XGMII |
> + * | || |
> + * | +--------------+ |
> + * | | Ethernet | |
> + * | | switch | |
> + * | +--------------+ |
> + * | || || || || |
> + * +==========================================+
> + * || || || || More external interfaces
> + *
> + * This SoC device has PCIe ethernet MAC directly attached to an integrated
> + * ethernet switch using XGMII interface. Since devicetree support is not
> + * available on this platform, a software node is created to enable
> + * fixed-link support using phylink driver.
> + */
> +
> +#include <linux/clk-provider.h>
> +#include <linux/dmi.h>
> +#include <linux/pci.h>
> +#include <linux/phy.h>
> +
> +#include "stmmac.h"
> +#include "dwxgmac2.h"
> +#include "dw25gmac.h"
> +
> +#define PCI_DEVICE_ID_BROADCOM_BCM8958X 0xa00d
> +#define BRCM_MAX_MTU 1500

> +#define READ_POLL_DELAY_US 100
> +#define READ_POLL_TIMEOUT_US 10000

These macros are unused. Why do you need them here?

> +#define DWMAC_125MHZ 125000000
> +#define DWMAC_250MHZ 250000000

Drop these and use the literals directly.

> +#define BRCM_XGMAC_NUM_VLAN_FILTERS 32
> +
> +/* TX and RX Queue counts */
> +#define BRCM_TX_Q_COUNT 4
> +#define BRCM_RX_Q_COUNT 4
> +

> +#define BRCM_XGMAC_DMA_TX_SIZE 1024
> +#define BRCM_XGMAC_DMA_RX_SIZE 1024

Unused.

> +#define BRCM_XGMAC_BAR0_MASK BIT(0)
> +
> +#define BRCM_XGMAC_IOMEM_MISC_REG_OFFSET 0x0
> +#define BRCM_XGMAC_IOMEM_MBOX_REG_OFFSET 0x1000
> +#define BRCM_XGMAC_IOMEM_CFG_REG_OFFSET 0x3000
> +
> +#define XGMAC_MMC_CTRL_RCHM_DISABLE BIT(31)
> +#define XGMAC_PCIE_CFG_MSIX_ADDR_MATCH_LOW 0x940
> +#define XGMAC_PCIE_CFG_MSIX_ADDR_MATCH_LO_VALUE 0x00000001
> +#define XGMAC_PCIE_CFG_MSIX_ADDR_MATCH_HIGH 0x944
> +#define XGMAC_PCIE_CFG_MSIX_ADDR_MATCH_HI_VALUE 0x88000000
> +
> +#define XGMAC_PCIE_MISC_MII_CTRL_OFFSET 0x4
> +#define XGMAC_PCIE_MISC_MII_CTRL_PAUSE_RX BIT(0)
> +#define XGMAC_PCIE_MISC_MII_CTRL_PAUSE_TX BIT(1)
> +#define XGMAC_PCIE_MISC_MII_CTRL_LINK_UP BIT(2)
> +#define XGMAC_PCIE_MISC_PCIESS_CTRL_OFFSET 0x8
> +#define XGMAC_PCIE_MISC_PCIESS_CTRL_EN_MSI_MSIX BIT(9)
> +#define XGMAC_PCIE_MISC_MSIX_ADDR_MATCH_LO_OFFSET 0x90
> +#define XGMAC_PCIE_MISC_MSIX_ADDR_MATCH_LO_VALUE 0x00000001
> +#define XGMAC_PCIE_MISC_MSIX_ADDR_MATCH_HI_OFFSET 0x94
> +#define XGMAC_PCIE_MISC_MSIX_ADDR_MATCH_HI_VALUE 0x88000000
> +#define XGMAC_PCIE_MISC_MSIX_VECTOR_MAP_EP2HOST0_OFFSET 0x700
> +#define XGMAC_PCIE_MISC_MSIX_VECTOR_MAP_EP2HOST0_VALUE 1
> +#define XGMAC_PCIE_MISC_MSIX_VECTOR_MAP_EP2HOST1_OFFSET 0x704
> +#define XGMAC_PCIE_MISC_MSIX_VECTOR_MAP_EP2HOST1_VALUE 1
> +#define XGMAC_PCIE_MISC_MSIX_VECTOR_MAP_EP2HOST_DBELL_OFFSET 0x728
> +#define XGMAC_PCIE_MISC_MSIX_VECTOR_MAP_EP2HOST_DBELL_VALUE 1
> +#define XGMAC_PCIE_MISC_MSIX_VECTOR_MAP_SBD_ALL_OFFSET 0x740
> +#define XGMAC_PCIE_MISC_MSIX_VECTOR_MAP_SBD_ALL_VALUE 0
> +
> +#define XGMAC_PCIE_MISC_FUNC_RESOURCES_PF0_OFFSET 0x804
> +
> +/* MSIX Vector map register starting offsets */
> +#define XGMAC_PCIE_MISC_MSIX_VECTOR_MAP_RX0_PF0_OFFSET 0x840
> +#define XGMAC_PCIE_MISC_MSIX_VECTOR_MAP_TX0_PF0_OFFSET 0x890
> +#define BRCM_MAX_DMA_CHANNEL_PAIRS 4
> +
> +#define BRCM_XGMAC_MSI_MAC_VECTOR 0
> +#define BRCM_XGMAC_MSI_RX_VECTOR_START 9
> +#define BRCM_XGMAC_MSI_TX_VECTOR_START 10
> +
> +static char *fixed_link_node_name = "fixed-link";
> +
> +static const struct property_entry fixed_link_properties[] = {
> + PROPERTY_ENTRY_U32("speed", 10000),
> + PROPERTY_ENTRY_BOOL("full-duplex"),
> + PROPERTY_ENTRY_BOOL("pause"),
> + { }
> +};
> +
> +struct brcm_priv_data {
> + void __iomem *mbox_regs; /* MBOX Registers*/
> + void __iomem *misc_regs; /* MISC Registers*/
> + void __iomem *xgmac_regs; /* XGMAC Registers*/
> + struct software_node fixed_link_node;
> +};
> +
> +struct dwxgmac_brcm_pci_info {
> + int (*setup)(struct pci_dev *pdev, struct plat_stmmacenet_data *plat);
> +};
> +
> +static void misc_iowrite(struct brcm_priv_data *brcm_priv,
> + u32 reg, u32 val)
> +{
> + iowrite32(val, brcm_priv->misc_regs + reg);
> +}
> +
> +static void dwxgmac_brcm_common_default_data(struct plat_stmmacenet_data *plat)
> +{
> + int i;
> +
> + plat->has_xgmac = 1;
> + plat->force_sf_dma_mode = 1;
> + plat->mac_port_sel_speed = SPEED_10000;

> + plat->clk_ptp_rate = DWMAC_125MHZ;
> + plat->clk_ref_rate = DWMAC_250MHZ;

Just 125000000 and 250000000. There is no need in defining the macro
with the names matching the numerical literals.

> + plat->tx_coe = 1;
> + plat->rx_coe = 1;
> + plat->max_speed = SPEED_10000;
> +
> + /* Set default value for multicast hash bins */
> + plat->multicast_filter_bins = HASH_TABLE_SIZE;
> +
> + /* Set default value for unicast filter entries */
> + plat->unicast_filter_entries = 1;
> +
> + /* Set the maxmtu to device's default */
> + plat->maxmtu = BRCM_MAX_MTU;
> +
> + /* Set default number of RX and TX queues to use */
> + plat->tx_queues_to_use = BRCM_TX_Q_COUNT;
> + plat->rx_queues_to_use = BRCM_RX_Q_COUNT;
> +
> + plat->tx_sched_algorithm = MTL_TX_ALGORITHM_SP;
> + for (i = 0; i < plat->tx_queues_to_use; i++) {
> + plat->tx_queues_cfg[i].use_prio = false;
> + plat->tx_queues_cfg[i].prio = 0;
> + plat->tx_queues_cfg[i].mode_to_use = MTL_QUEUE_AVB;
> + }
> +
> + plat->rx_sched_algorithm = MTL_RX_ALGORITHM_SP;
> + for (i = 0; i < plat->rx_queues_to_use; i++) {
> + plat->rx_queues_cfg[i].use_prio = false;
> + plat->rx_queues_cfg[i].mode_to_use = MTL_QUEUE_AVB;
> + plat->rx_queues_cfg[i].pkt_route = 0x0;
> + plat->rx_queues_cfg[i].chan = i;
> + }
> +}
> +
> +static int dwxgmac_brcm_default_data(struct pci_dev *pdev,
> + struct plat_stmmacenet_data *plat)
> +{
> + /* Set common default data first */
> + dwxgmac_brcm_common_default_data(plat);
> +
> + plat->snps_id = DW25GMAC_CORE_4_00;
> + plat->snps_dev_id = DW25GMAC_ID;
> + plat->bus_id = 0;
> + plat->phy_addr = 0;

> + plat->phy_interface = PHY_INTERFACE_MODE_USXGMII;

Really, USXGMII? Universal Serial XGMII? Synopsys call it just XGMII:
https://www.synopsys.com/dw/ipdir.php?ds=dwc_25g_ethernet_mac_ip

> +
> + plat->dma_cfg->pbl = 32;
> + plat->dma_cfg->pblx8 = 0;
> + plat->dma_cfg->aal = 0;
> + plat->dma_cfg->eame = 1;
> +
> + plat->axi->axi_wr_osr_lmt = 31;
> + plat->axi->axi_rd_osr_lmt = 31;
> + plat->axi->axi_fb = 0;
> + plat->axi->axi_blen[0] = 4;
> + plat->axi->axi_blen[1] = 8;
> + plat->axi->axi_blen[2] = 16;
> + plat->axi->axi_blen[3] = 32;
> + plat->axi->axi_blen[4] = 64;
> + plat->axi->axi_blen[5] = 128;
> + plat->axi->axi_blen[6] = 256;
> +

> + plat->msi_mac_vec = BRCM_XGMAC_MSI_MAC_VECTOR;
> + plat->msi_rx_base_vec = BRCM_XGMAC_MSI_RX_VECTOR_START;
> + plat->msi_tx_base_vec = BRCM_XGMAC_MSI_TX_VECTOR_START;

Please see my next comments about these fields utilization.

> +
> + return 0;
> +}
> +
> +static struct dwxgmac_brcm_pci_info dwxgmac_brcm_pci_info = {
> + .setup = dwxgmac_brcm_default_data,
> +};
> +
> +static void brcm_config_misc_regs(struct pci_dev *pdev,
> + struct brcm_priv_data *brcm_priv)
> +{
> + pci_write_config_dword(pdev, XGMAC_PCIE_CFG_MSIX_ADDR_MATCH_LOW,
> + XGMAC_PCIE_CFG_MSIX_ADDR_MATCH_LO_VALUE);
> + pci_write_config_dword(pdev, XGMAC_PCIE_CFG_MSIX_ADDR_MATCH_HIGH,
> + XGMAC_PCIE_CFG_MSIX_ADDR_MATCH_HI_VALUE);
> +
> + misc_iowrite(brcm_priv, XGMAC_PCIE_MISC_MSIX_ADDR_MATCH_LO_OFFSET,
> + XGMAC_PCIE_MISC_MSIX_ADDR_MATCH_LO_VALUE);
> + misc_iowrite(brcm_priv, XGMAC_PCIE_MISC_MSIX_ADDR_MATCH_HI_OFFSET,
> + XGMAC_PCIE_MISC_MSIX_ADDR_MATCH_HI_VALUE);
> +
> + /* Enable Switch Link */
> + misc_iowrite(brcm_priv, XGMAC_PCIE_MISC_MII_CTRL_OFFSET,
> + XGMAC_PCIE_MISC_MII_CTRL_PAUSE_RX |
> + XGMAC_PCIE_MISC_MII_CTRL_PAUSE_TX |
> + XGMAC_PCIE_MISC_MII_CTRL_LINK_UP);
> +}
> +
> +static int brcm_config_multi_msi(struct pci_dev *pdev,
> + struct plat_stmmacenet_data *plat,
> + struct stmmac_resources *res)
> +{
> + int ret, i;
> +

> + if (plat->msi_rx_base_vec >= STMMAC_MSI_VEC_MAX ||
> + plat->msi_tx_base_vec >= STMMAC_MSI_VEC_MAX) {

Please see my next comment about these fields and STMMAC_MSI_VEC_MAX
utilization.

> + dev_err(&pdev->dev, "%s: Invalid RX & TX vector defined\n",
> + __func__);
> + return -EINVAL;
> + }
> +
> + ret = pci_alloc_irq_vectors(pdev, 2, STMMAC_MSI_VEC_MAX,
> + PCI_IRQ_MSI | PCI_IRQ_MSIX);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "%s: multi MSI enablement failed\n",
> + __func__);
> + return ret;
> + }
> +
> + /* For RX MSI */
> + for (i = 0; i < plat->rx_queues_to_use; i++)
> + res->rx_irq[i] = pci_irq_vector(pdev,
> + plat->msi_rx_base_vec + i * 2);
> +
> + /* For TX MSI */
> + for (i = 0; i < plat->tx_queues_to_use; i++)
> + res->tx_irq[i] = pci_irq_vector(pdev,
> + plat->msi_tx_base_vec + i * 2);
> +

> + if (plat->msi_mac_vec < STMMAC_MSI_VEC_MAX)
> + res->irq = pci_irq_vector(pdev, plat->msi_mac_vec);

What if msi_mac_vec is greater than STMMAC_MSI_VEC_MAX? Will your
device work without delivering the MAC IRQs? I doubt so.

In anyway see my next comment.

> +
> + plat->flags |= STMMAC_FLAG_MULTI_MSI_EN;
> + plat->flags |= STMMAC_FLAG_TSO_EN;
> +
> + return 0;
> +}
> +
> +static int dwxgmac_brcm_pci_probe(struct pci_dev *pdev,
> + const struct pci_device_id *id)
> +{
> + struct dwxgmac_brcm_pci_info *info =
> + (struct dwxgmac_brcm_pci_info *)id->driver_data;
> + struct plat_stmmacenet_data *plat;
> + struct brcm_priv_data *brcm_priv;
> + struct stmmac_resources res;
> + struct device *dev;
> + int rx_offset;
> + int tx_offset;
> + int vector;
> + int ret;
> +
> + dev = &pdev->dev;
> +
> + brcm_priv = devm_kzalloc(&pdev->dev, sizeof(*brcm_priv), GFP_KERNEL);
> + if (!brcm_priv)
> + return -ENOMEM;
> +
> + plat = devm_kzalloc(&pdev->dev, sizeof(*plat), GFP_KERNEL);
> + if (!plat)
> + return -ENOMEM;
> +
> + plat->dma_cfg = devm_kzalloc(&pdev->dev, sizeof(*plat->dma_cfg),
> + GFP_KERNEL);
> + if (!plat->dma_cfg)
> + return -ENOMEM;
> +
> + plat->axi = devm_kzalloc(&pdev->dev, sizeof(*plat->axi), GFP_KERNEL);
> + if (!plat->axi)
> + return -ENOMEM;
> +
> + /* This device is directly attached to the switch chip internal to the
> + * SoC using XGMII interface. Since no MDIO is present, register
> + * fixed-link software_node to create phylink.
> + */
> + plat->port_node = fwnode_create_software_node(NULL, NULL);
> + brcm_priv->fixed_link_node.name = fixed_link_node_name;
> + brcm_priv->fixed_link_node.properties = fixed_link_properties;
> + brcm_priv->fixed_link_node.parent = to_software_node(plat->port_node);
> + device_add_software_node(dev, &brcm_priv->fixed_link_node);
> +
> + /* Disable D3COLD as our device does not support it */
> + pci_d3cold_disable(pdev);
> +
> + /* Enable PCI device */
> + ret = pcim_enable_device(pdev);
> + if (ret) {
> + dev_err(&pdev->dev, "%s: ERROR: failed to enable device\n",
> + __func__);
> + return ret;
> + }
> +
> + /* Get the base address of device */
> + ret = pcim_iomap_regions(pdev, BRCM_XGMAC_BAR0_MASK, pci_name(pdev));
> + if (ret)
> + return ret;
> + pci_set_master(pdev);
> +
> + memset(&res, 0, sizeof(res));
> + res.addr = pcim_iomap_table(pdev)[0];
> + /* MISC Regs */
> + brcm_priv->misc_regs = res.addr + BRCM_XGMAC_IOMEM_MISC_REG_OFFSET;
> + /* MBOX Regs */
> + brcm_priv->mbox_regs = res.addr + BRCM_XGMAC_IOMEM_MBOX_REG_OFFSET;
> + /* XGMAC config Regs */
> + res.addr += BRCM_XGMAC_IOMEM_CFG_REG_OFFSET;
> + brcm_priv->xgmac_regs = res.addr;
> +
> + plat->bsp_priv = brcm_priv;
> +
> + /* Initialize all MSI vectors to invalid so that it can be set
> + * according to platform data settings below.
> + * Note: MSI vector takes value from 0 up to 31 (STMMAC_MSI_VEC_MAX)
> + */

> + plat->msi_mac_vec = STMMAC_MSI_VEC_MAX;
> + plat->msi_wol_vec = STMMAC_MSI_VEC_MAX;
> + plat->msi_lpi_vec = STMMAC_MSI_VEC_MAX;
> + plat->msi_sfty_ce_vec = STMMAC_MSI_VEC_MAX;
> + plat->msi_sfty_ue_vec = STMMAC_MSI_VEC_MAX;
> + plat->msi_rx_base_vec = STMMAC_MSI_VEC_MAX;
> + plat->msi_tx_base_vec = STMMAC_MSI_VEC_MAX;

Please don't use these fields and the STMMAC_MSI_VEC_MAX macro. Either
have the BRCM_XGMAC_MSI* macros utilized directly or define the
device-specific data in the glue driver (in brcm_priv_data if you
wish). Really the MSI vectors aren't related to any DW *MAC IP-core
these are the pure vendor platform-specific settings.

The fields originally have been introduced by the Intel developers,
who AFAICS just found it easier to extend the generic platform-data
structure instead of introducing the new Intel MAC-specific data.

I am going to drop these fields in a future cleanup patchset so to
reduce the plat_stmmacenet_data structure complexity.

-Serge(y)

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