Some systems implement a system MAC address object in the ACPI table, using either \\_SB.AMAC or \\MACA object names. This system MAC address, when enabled, is intended to override the permanent MAC address of a network controller in a docking station connected to the system.
Implement lookup of the relevant ACPI object names and use them to initialize the MAC address. Limit the scope to I225/I226 device IDs used in docking stations, to avoid interfering with onboard I225/I226 NICs. On systems where the feature is disabled or unsupported, the ACPI objects do not exist or do not contain a valid Ethernet MAC, causing a fallback to the existing MAC address initialization path. Assisted-by: GitHub-Copilot:claude-opus-4.7 Signed-off-by: Dima Ruinskiy <[email protected]> --- v2: limit scope to dock device ids v1: initial version --- drivers/net/ethernet/intel/igc/igc.h | 1 + drivers/net/ethernet/intel/igc/igc_base.c | 8 +++ drivers/net/ethernet/intel/igc/igc_hw.h | 2 + drivers/net/ethernet/intel/igc/igc_main.c | 69 +++++++++++++++++++++-- 4 files changed, 76 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/intel/igc/igc.h b/drivers/net/ethernet/intel/igc/igc.h index 88291f775c22..05affaa04aa4 100644 --- a/drivers/net/ethernet/intel/igc/igc.h +++ b/drivers/net/ethernet/intel/igc/igc.h @@ -567,6 +567,7 @@ enum igc_tx_flags { enum igc_boards { board_base, + board_dock, }; /* The largest size we can write to the descriptor is 65535. In order to diff --git a/drivers/net/ethernet/intel/igc/igc_base.c b/drivers/net/ethernet/intel/igc/igc_base.c index ab9120a3127f..c9067cc79b69 100644 --- a/drivers/net/ethernet/intel/igc/igc_base.c +++ b/drivers/net/ethernet/intel/igc/igc_base.c @@ -474,4 +474,12 @@ const struct igc_info igc_base_info = { .get_invariants = igc_get_invariants_base, .mac_ops = &igc_mac_ops_base, .phy_ops = &igc_phy_ops_base, + .is_dock = false, +}; + +const struct igc_info igc_dock_info = { + .get_invariants = igc_get_invariants_base, + .mac_ops = &igc_mac_ops_base, + .phy_ops = &igc_phy_ops_base, + .is_dock = true, }; diff --git a/drivers/net/ethernet/intel/igc/igc_hw.h b/drivers/net/ethernet/intel/igc/igc_hw.h index 62aaee55668a..d14b7666b5d7 100644 --- a/drivers/net/ethernet/intel/igc/igc_hw.h +++ b/drivers/net/ethernet/intel/igc/igc_hw.h @@ -69,9 +69,11 @@ struct igc_info { struct igc_mac_operations *mac_ops; const struct igc_phy_operations *phy_ops; struct igc_nvm_operations *nvm_ops; + bool is_dock; }; extern const struct igc_info igc_base_info; +extern const struct igc_info igc_dock_info; enum igc_forced_speed_duplex { IGC_FORCED_10H, diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c index 82800a4a6d6c..15d0815a2110 100644 --- a/drivers/net/ethernet/intel/igc/igc_main.c +++ b/drivers/net/ethernet/intel/igc/igc_main.c @@ -11,6 +11,8 @@ #include <net/pkt_sched.h> #include <linux/bpf_trace.h> #include <net/xdp_sock_drv.h> +#include <linux/acpi.h> +#include <linux/hex.h> #include <linux/pci.h> #include <linux/mdio.h> @@ -44,6 +46,7 @@ static const char igc_copyright[] = static const struct igc_info *igc_info_tbl[] = { [board_base] = &igc_base_info, + [board_dock] = &igc_dock_info, }; static const struct pci_device_id igc_pci_tbl[] = { @@ -54,8 +57,8 @@ static const struct pci_device_id igc_pci_tbl[] = { { PCI_VDEVICE(INTEL, IGC_DEV_ID_I225_K), .driver_data = board_base }, { PCI_VDEVICE(INTEL, IGC_DEV_ID_I225_K2), .driver_data = board_base }, { PCI_VDEVICE(INTEL, IGC_DEV_ID_I226_K), .driver_data = board_base }, - { PCI_VDEVICE(INTEL, IGC_DEV_ID_I225_LMVP), .driver_data = board_base }, - { PCI_VDEVICE(INTEL, IGC_DEV_ID_I226_LMVP), .driver_data = board_base }, + { PCI_VDEVICE(INTEL, IGC_DEV_ID_I225_LMVP), .driver_data = board_dock }, + { PCI_VDEVICE(INTEL, IGC_DEV_ID_I226_LMVP), .driver_data = board_dock }, { PCI_VDEVICE(INTEL, IGC_DEV_ID_I225_IT), .driver_data = board_base }, { PCI_VDEVICE(INTEL, IGC_DEV_ID_I226_LM), .driver_data = board_base }, { PCI_VDEVICE(INTEL, IGC_DEV_ID_I226_V), .driver_data = board_base }, @@ -7116,6 +7119,57 @@ static enum hrtimer_restart igc_qbv_scheduling_timer(struct hrtimer *timer) return HRTIMER_NORESTART; } +static bool igc_get_acpi_mac_passthru(u8 *mac) +{ + static const struct { + const char *name; + acpi_object_type type; + u32 length; + } sources[] = { + { "\\_SB.AMAC", ACPI_TYPE_BUFFER, 23 }, + { "\\MACA", ACPI_TYPE_STRING, 22 }, + }; + struct acpi_buffer buffer; + union acpi_object *obj; + bool mac_found = false; + acpi_status status; + u8 buf[ETH_ALEN]; + int i; + + if (!IS_ENABLED(CONFIG_ACPI)) + return false; + + for (i = 0; i < ARRAY_SIZE(sources) && !mac_found; i++) { + buffer.length = ACPI_ALLOCATE_BUFFER; + buffer.pointer = NULL; + + status = acpi_evaluate_object(NULL, (char *)sources[i].name, + NULL, &buffer); + if (ACPI_FAILURE(status)) + continue; + + obj = buffer.pointer; + if (!obj || obj->type != sources[i].type || + obj->string.length != sources[i].length) + goto free_obj; + + if (!strncmp(obj->string.pointer, "_AUXMAC_#", 9) || + obj->string.pointer[21] != '#') + goto free_obj; + + if (hex2bin(buf, obj->string.pointer + 9, ETH_ALEN) || + !is_valid_ether_addr(buf)) + goto free_obj; + + ether_addr_copy(mac, buf); + mac_found = true; +free_obj: + kfree(obj); + } + + return mac_found; +} + /** * igc_probe - Device Initialization Routine * @pdev: PCI device information struct @@ -7279,9 +7333,16 @@ static int igc_probe(struct pci_dev *pdev, } if (eth_platform_get_mac_address(&pdev->dev, hw->mac.addr)) { - /* copy the MAC address out of the NVM */ - if (hw->mac.ops.read_mac_addr(hw)) + /* Look for a system-provided MAC in the ACPI table before + * falling back to reading the address from the NVM. + */ + if (ei->is_dock && igc_get_acpi_mac_passthru(hw->mac.addr)) { + netdev->addr_assign_type = NET_ADDR_STOLEN; + dev_info(&pdev->dev, "Using ACPI pass-thru MAC addr %pM\n", + hw->mac.addr); + } else if (hw->mac.ops.read_mac_addr(hw)) { dev_err(&pdev->dev, "NVM Read Error\n"); + } } eth_hw_addr_set(netdev, hw->mac.addr); -- 2.43.7
