STRUCT EFX_SPECIAL_BUFFER(9)

✨ NAME ✨

struct efx_special_buffer — the DMA buffer entered into the buffer table, bestie 💅

Welcome to the struct efx_special_buffer(9) page in the Kernel API Manual. Pull up a chair, this one's lowkey iconic.

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🧚 SYNOPSIS 🧚

It's giving very demure, very mindful struct definition:

       struct efx_special_buffer {
           struct efx_buffer buf;
           unsigned int index;
           unsigned int entries;
        };

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🎀 Members 🎀

• buf — Standard struct efx_buffer. The classic, the blueprint, no notes. 🫶
• index — Buffer index within the controller's buffer table. Homegirl's address, basically.
• entries — Number of buffer table entries. Counting era 💅

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💖 Description 💖

okay so picture this: the NIC has a buffer table that maps buffers of size EFX_BUF_SIZE. That's the whole vibe. ✨

Event and descriptor rings are addressed via one or more buffer table entries, and because of that they can be physically non-contiguous — although we currently do not take advantage of that, bestie. The potential is there, we're just not using it. Not me ignoring a feature 😭

On Falcon and Siena, we have to take care of allocating and initialising the entries ourselves. Main character chores, honestly. On later hardware, this is managed by the firmware and index and entries are left as 0. Periodt. 💀

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🌈 SEE ALSO 🌈

The whole squad, no cap. Go peep the Kernel file ./drivers/net/ethernet/sfc/siena/net_driver.h and also:

• struct efx_buffer(9)
• struct efx_tx_buffer(9)
• struct efx_tx_queue(9)
• struct efx_rx_buffer(9)
• struct efx_rx_page_state(9)
• struct efx_rx_queue(9)
• struct efx_channel(9)
• struct efx_msi_context(9)
• struct efx_channel_type(9)
• struct efx_link_state(9)
• enum efx_phy_mode(9)
• struct efx_hw_stat_desc(9)
• struct efx_rss_context(9)
• struct efx_arfs_rule(9)
• struct efx_async_filter_insertion(9)
• struct efx_nic(9)
• struct efx_nic_type(9)

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mwah 💋 this lil page lives in the Kernel API Manual as struct efx_special_buffer(9), sourced from ./drivers/net/ethernet/sfc/siena, and dated October 2026. stan. 🎀🦋