igc_write_ivar(9)

🎀 NAME 🎀

Hey bestie 💖 welcome to igc_write_ivar(9), straight outta the Kernel API Manual. This page is all about igc_write_ivar — configure ivar for given MSI-X vector. That's the name, that's the vibe, periodt.

✨ SYNOPSIS ✨

No cap, here's the exact signature:

void igc_write_ivar (struct igc_hw *hw , int msix_vector , int index , int offset );

🌸 ARGUMENTS 🌸

Okay so this function takes four things, and every single one matters:

• hw — pointer to the HW structure. Your hardware main character 🫶
• msix_vector — vector number we are allocating to a given ring.
• index — row index of IVAR register to write within IVAR table.
• offset — column offset of in IVAR, should be multiple of 8. Lowkey important: multiple of 8, bestie.

🦋 DESCRIPTION 🦋

The IVAR table consists of 2 columns, each containing a cause allocation for an Rx and Tx ring, and a variable number of rows depending on the number of queues supported. So it's giving tiny-grid energy: two columns, cause allocation for Rx and Tx rings, and the row count is not fixed — it changes with how many queues are supported. Slay 💅

💖 SEE ALSO 💖

Go be nosy, bestie — these are all the neighbors 👑:

• Kernel file: ./drivers/net/ethernet/intel/igc/igc_main.c
• igc_power_up_link(9)
• igc_release_hw_control(9)
• igc_get_hw_control(9)
• igc_clean_tx_ring(9)
• igc_free_tx_resources(9)
• igc_free_all_tx_resources(9)
• igc_clean_all_tx_rings(9)
• igc_disable_all_tx_rings_hw(9)
• igc_setup_tx_resources(9)
• igc_setup_all_tx_resources(9)
• igc_clean_rx_ring(9)
• igc_clean_all_rx_rings(9)
• igc_free_rx_resources(9)
• igc_free_all_rx_resources(9)
• igc_setup_rx_resources(9)
• igc_setup_all_rx_resources(9)
• igc_configure_rx_ring(9)
• igc_configure_rx(9)
• igc_configure_tx_ring(9)
• igc_configure_tx(9)
• igc_setup_mrqc(9)
• igc_setup_rctl(9)
• igc_setup_tctl(9)
• igc_set_mac_filter_hw(9)
• igc_clear_mac_filter_hw(9)
• igc_set_mac(9)
• igc_write_mc_addr_list(9)
• igc_process_skb_fields(9)
• igc_add_rx_frag(9)
• igc_reuse_rx_page(9)
• igc_is_non_eop(9)
• igc_cleanup_headers(9)
• igc_alloc_rx_buffers(9)
• igc_clean_tx_irq(9)
• igc_add_mac_filter(9)
• igc_del_mac_filter(9)
• igc_add_vlan_prio_filter(9)
• igc_del_vlan_prio_filter(9)
• igc_add_etype_filter(9)
• igc_del_etype_filter(9)
• igc_get_nfc_rule(9)
• igc_del_nfc_rule(9)
• igc_add_nfc_rule(9)
• igc_enable_empty_addr_recv(9)
• igc_set_rx_mode(9)
• igc_configure(9)
• igc_configure_msix(9)
• igc_irq_enable(9)
• igc_irq_disable(9)
• igc_reset_q_vector(9)
• igc_free_q_vector(9)
• igc_free_q_vectors(9)
• igc_update_itr(9)
• igc_set_interrupt_capability(9)
• igc_update_ring_itr(9)
• igc_cache_ring_register(9)
• igc_poll(9)
• igc_alloc_q_vector(9)
• igc_alloc_q_vectors(9)
• igc_init_interrupt_scheme(9)
• igc_sw_init(9)
• igc_up(9)
• igc_update_stats(9)
• igc_down(9)
• igc_change_mtu(9)
• igc_tx_timeout(9)
• igc_get_stats64(9)
• igc_msix_other(9)
• igc_request_msix(9)
• igc_clear_interrupt_scheme(9)
• igc_has_link(9)
• igc_watchdog(9)
• igc_intr_msi(9)
• igc_intr(9)
• igc_request_irq(9)
• __igc_open(9)
• __igc_close(9)
• igc_probe(9)
• igc_remove(9)
• igc_io_error_detected(9)
• igc_io_slot_reset(9)
• igc_io_resume(9)
• igc_reinit_queues(9)
• igc_get_hw_dev(9)
• igc_init_module(9)
• igc_exit_module(9)

Source / version / date sign-off: ./drivers/net/ethernet/intel/igc · October 2026 · igc_write_ivar(9) — mwah, bye bestie 💋✨