linux/drivers/net/ethernet/intel/i40e/i40e_txrx.c

// SPDX-License-Identifier: GPL-2.0
/* Copyright(c) 2013 - 2018 Intel Corporation. */

#include <linux/bpf_trace.h>
#include <linux/net/intel/libie/rx.h>
#include <linux/prefetch.h>
#include <linux/sctp.h>
#include <net/mpls.h>
#include <net/xdp.h>
#include "i40e_txrx_common.h"
#include "i40e_trace.h"
#include "i40e_xsk.h"

#define I40E_TXD_CMD
/**
 * i40e_fdir - Generate a Flow Director descriptor based on fdata
 * @tx_ring: Tx ring to send buffer on
 * @fdata: Flow director filter data
 * @add: Indicate if we are adding a rule or deleting one
 *
 **/
static void i40e_fdir(struct i40e_ring *tx_ring,
		      struct i40e_fdir_filter *fdata, bool add)
{}

#define I40E_FD_CLEAN_DELAY
/**
 * i40e_program_fdir_filter - Program a Flow Director filter
 * @fdir_data: Packet data that will be filter parameters
 * @raw_packet: the pre-allocated packet buffer for FDir
 * @pf: The PF pointer
 * @add: True for add/update, False for remove
 **/
static int i40e_program_fdir_filter(struct i40e_fdir_filter *fdir_data,
				    u8 *raw_packet, struct i40e_pf *pf,
				    bool add)
{}

/**
 * i40e_create_dummy_packet - Constructs dummy packet for HW
 * @dummy_packet: preallocated space for dummy packet
 * @ipv4: is layer 3 packet of version 4 or 6
 * @l4proto: next level protocol used in data portion of l3
 * @data: filter data
 *
 * Returns address of layer 4 protocol dummy packet.
 **/
static char *i40e_create_dummy_packet(u8 *dummy_packet, bool ipv4, u8 l4proto,
				      struct i40e_fdir_filter *data)
{}

/**
 * i40e_create_dummy_udp_packet - helper function to create UDP packet
 * @raw_packet: preallocated space for dummy packet
 * @ipv4: is layer 3 packet of version 4 or 6
 * @l4proto: next level protocol used in data portion of l3
 * @data: filter data
 *
 * Helper function to populate udp fields.
 **/
static void i40e_create_dummy_udp_packet(u8 *raw_packet, bool ipv4, u8 l4proto,
					 struct i40e_fdir_filter *data)
{}

/**
 * i40e_create_dummy_tcp_packet - helper function to create TCP packet
 * @raw_packet: preallocated space for dummy packet
 * @ipv4: is layer 3 packet of version 4 or 6
 * @l4proto: next level protocol used in data portion of l3
 * @data: filter data
 *
 * Helper function to populate tcp fields.
 **/
static void i40e_create_dummy_tcp_packet(u8 *raw_packet, bool ipv4, u8 l4proto,
					 struct i40e_fdir_filter *data)
{}

/**
 * i40e_create_dummy_sctp_packet - helper function to create SCTP packet
 * @raw_packet: preallocated space for dummy packet
 * @ipv4: is layer 3 packet of version 4 or 6
 * @l4proto: next level protocol used in data portion of l3
 * @data: filter data
 *
 * Helper function to populate sctp fields.
 **/
static void i40e_create_dummy_sctp_packet(u8 *raw_packet, bool ipv4,
					  u8 l4proto,
					  struct i40e_fdir_filter *data)
{}

/**
 * i40e_prepare_fdir_filter - Prepare and program fdir filter
 * @pf: physical function to attach filter to
 * @fd_data: filter data
 * @add: add or delete filter
 * @packet_addr: address of dummy packet, used in filtering
 * @payload_offset: offset from dummy packet address to user defined data
 * @pctype: Packet type for which filter is used
 *
 * Helper function to offset data of dummy packet, program it and
 * handle errors.
 **/
static int i40e_prepare_fdir_filter(struct i40e_pf *pf,
				    struct i40e_fdir_filter *fd_data,
				    bool add, char *packet_addr,
				    int payload_offset, u8 pctype)
{}

/**
 * i40e_change_filter_num - Prepare and program fdir filter
 * @ipv4: is layer 3 packet of version 4 or 6
 * @add: add or delete filter
 * @ipv4_filter_num: field to update
 * @ipv6_filter_num: field to update
 *
 * Update filter number field for pf.
 **/
static void i40e_change_filter_num(bool ipv4, bool add, u16 *ipv4_filter_num,
				   u16 *ipv6_filter_num)
{}

#define I40E_UDPIP_DUMMY_PACKET_LEN
#define I40E_UDPIP6_DUMMY_PACKET_LEN
/**
 * i40e_add_del_fdir_udp - Add/Remove UDP filters
 * @vsi: pointer to the targeted VSI
 * @fd_data: the flow director data required for the FDir descriptor
 * @add: true adds a filter, false removes it
 * @ipv4: true is v4, false is v6
 *
 * Returns 0 if the filters were successfully added or removed
 **/
static int i40e_add_del_fdir_udp(struct i40e_vsi *vsi,
				 struct i40e_fdir_filter *fd_data,
				 bool add,
				 bool ipv4)
{}

#define I40E_TCPIP_DUMMY_PACKET_LEN
#define I40E_TCPIP6_DUMMY_PACKET_LEN
/**
 * i40e_add_del_fdir_tcp - Add/Remove TCPv4 filters
 * @vsi: pointer to the targeted VSI
 * @fd_data: the flow director data required for the FDir descriptor
 * @add: true adds a filter, false removes it
 * @ipv4: true is v4, false is v6
 *
 * Returns 0 if the filters were successfully added or removed
 **/
static int i40e_add_del_fdir_tcp(struct i40e_vsi *vsi,
				 struct i40e_fdir_filter *fd_data,
				 bool add,
				 bool ipv4)
{}

#define I40E_SCTPIP_DUMMY_PACKET_LEN
#define I40E_SCTPIP6_DUMMY_PACKET_LEN
/**
 * i40e_add_del_fdir_sctp - Add/Remove SCTPv4 Flow Director filters for
 * a specific flow spec
 * @vsi: pointer to the targeted VSI
 * @fd_data: the flow director data required for the FDir descriptor
 * @add: true adds a filter, false removes it
 * @ipv4: true is v4, false is v6
 *
 * Returns 0 if the filters were successfully added or removed
 **/
static int i40e_add_del_fdir_sctp(struct i40e_vsi *vsi,
				  struct i40e_fdir_filter *fd_data,
				  bool add,
				  bool ipv4)
{}

#define I40E_IP_DUMMY_PACKET_LEN
#define I40E_IP6_DUMMY_PACKET_LEN
/**
 * i40e_add_del_fdir_ip - Add/Remove IPv4 Flow Director filters for
 * a specific flow spec
 * @vsi: pointer to the targeted VSI
 * @fd_data: the flow director data required for the FDir descriptor
 * @add: true adds a filter, false removes it
 * @ipv4: true is v4, false is v6
 *
 * Returns 0 if the filters were successfully added or removed
 **/
static int i40e_add_del_fdir_ip(struct i40e_vsi *vsi,
				struct i40e_fdir_filter *fd_data,
				bool add,
				bool ipv4)
{}

/**
 * i40e_add_del_fdir - Build raw packets to add/del fdir filter
 * @vsi: pointer to the targeted VSI
 * @input: filter to add or delete
 * @add: true adds a filter, false removes it
 *
 **/
int i40e_add_del_fdir(struct i40e_vsi *vsi,
		      struct i40e_fdir_filter *input, bool add)
{}

/**
 * i40e_fd_handle_status - check the Programming Status for FD
 * @rx_ring: the Rx ring for this descriptor
 * @qword0_raw: qword0
 * @qword1: qword1 after le_to_cpu
 * @prog_id: the id originally used for programming
 *
 * This is used to verify if the FD programming or invalidation
 * requested by SW to the HW is successful or not and take actions accordingly.
 **/
static void i40e_fd_handle_status(struct i40e_ring *rx_ring, u64 qword0_raw,
				  u64 qword1, u8 prog_id)
{}

/**
 * i40e_unmap_and_free_tx_resource - Release a Tx buffer
 * @ring:      the ring that owns the buffer
 * @tx_buffer: the buffer to free
 **/
static void i40e_unmap_and_free_tx_resource(struct i40e_ring *ring,
					    struct i40e_tx_buffer *tx_buffer)
{}

/**
 * i40e_clean_tx_ring - Free any empty Tx buffers
 * @tx_ring: ring to be cleaned
 **/
void i40e_clean_tx_ring(struct i40e_ring *tx_ring)
{}

/**
 * i40e_free_tx_resources - Free Tx resources per queue
 * @tx_ring: Tx descriptor ring for a specific queue
 *
 * Free all transmit software resources
 **/
void i40e_free_tx_resources(struct i40e_ring *tx_ring)
{}

/**
 * i40e_get_tx_pending - how many tx descriptors not processed
 * @ring: the ring of descriptors
 * @in_sw: use SW variables
 *
 * Since there is no access to the ring head register
 * in XL710, we need to use our local copies
 **/
u32 i40e_get_tx_pending(struct i40e_ring *ring, bool in_sw)
{}

/**
 * i40e_detect_recover_hung - Function to detect and recover hung_queues
 * @pf: pointer to PF struct
 *
 * LAN VSI has netdev and netdev has TX queues. This function is to check
 * each of those TX queues if they are hung, trigger recovery by issuing
 * SW interrupt.
 **/
void i40e_detect_recover_hung(struct i40e_pf *pf)
{}

/**
 * i40e_clean_tx_irq - Reclaim resources after transmit completes
 * @vsi: the VSI we care about
 * @tx_ring: Tx ring to clean
 * @napi_budget: Used to determine if we are in netpoll
 * @tx_cleaned: Out parameter set to the number of TXes cleaned
 *
 * Returns true if there's any budget left (e.g. the clean is finished)
 **/
static bool i40e_clean_tx_irq(struct i40e_vsi *vsi,
			      struct i40e_ring *tx_ring, int napi_budget,
			      unsigned int *tx_cleaned)
{}

/**
 * i40e_enable_wb_on_itr - Arm hardware to do a wb, interrupts are not enabled
 * @vsi: the VSI we care about
 * @q_vector: the vector on which to enable writeback
 *
 **/
static void i40e_enable_wb_on_itr(struct i40e_vsi *vsi,
				  struct i40e_q_vector *q_vector)
{}

/**
 * i40e_force_wb - Issue SW Interrupt so HW does a wb
 * @vsi: the VSI we care about
 * @q_vector: the vector  on which to force writeback
 *
 **/
void i40e_force_wb(struct i40e_vsi *vsi, struct i40e_q_vector *q_vector)
{}

static inline bool i40e_container_is_rx(struct i40e_q_vector *q_vector,
					struct i40e_ring_container *rc)
{}

static inline unsigned int i40e_itr_divisor(struct i40e_q_vector *q_vector)
{}

/**
 * i40e_update_itr - update the dynamic ITR value based on statistics
 * @q_vector: structure containing interrupt and ring information
 * @rc: structure containing ring performance data
 *
 * Stores a new ITR value based on packets and byte
 * counts during the last interrupt.  The advantage of per interrupt
 * computation is faster updates and more accurate ITR for the current
 * traffic pattern.  Constants in this function were computed
 * based on theoretical maximum wire speed and thresholds were set based
 * on testing data as well as attempting to minimize response time
 * while increasing bulk throughput.
 **/
static void i40e_update_itr(struct i40e_q_vector *q_vector,
			    struct i40e_ring_container *rc)
{}

static struct i40e_rx_buffer *i40e_rx_bi(struct i40e_ring *rx_ring, u32 idx)
{}

/**
 * i40e_reuse_rx_page - page flip buffer and store it back on the ring
 * @rx_ring: rx descriptor ring to store buffers on
 * @old_buff: donor buffer to have page reused
 *
 * Synchronizes page for reuse by the adapter
 **/
static void i40e_reuse_rx_page(struct i40e_ring *rx_ring,
			       struct i40e_rx_buffer *old_buff)
{}

/**
 * i40e_clean_programming_status - clean the programming status descriptor
 * @rx_ring: the rx ring that has this descriptor
 * @qword0_raw: qword0
 * @qword1: qword1 representing status_error_len in CPU ordering
 *
 * Flow director should handle FD_FILTER_STATUS to check its filter programming
 * status being successful or not and take actions accordingly. FCoE should
 * handle its context/filter programming/invalidation status and take actions.
 *
 * Returns an i40e_rx_buffer to reuse if the cleanup occurred, otherwise NULL.
 **/
void i40e_clean_programming_status(struct i40e_ring *rx_ring, u64 qword0_raw,
				   u64 qword1)
{}

/**
 * i40e_setup_tx_descriptors - Allocate the Tx descriptors
 * @tx_ring: the tx ring to set up
 *
 * Return 0 on success, negative on error
 **/
int i40e_setup_tx_descriptors(struct i40e_ring *tx_ring)
{}

static void i40e_clear_rx_bi(struct i40e_ring *rx_ring)
{}

/**
 * i40e_clean_rx_ring - Free Rx buffers
 * @rx_ring: ring to be cleaned
 **/
void i40e_clean_rx_ring(struct i40e_ring *rx_ring)
{}

/**
 * i40e_free_rx_resources - Free Rx resources
 * @rx_ring: ring to clean the resources from
 *
 * Free all receive software resources
 **/
void i40e_free_rx_resources(struct i40e_ring *rx_ring)
{}

/**
 * i40e_setup_rx_descriptors - Allocate Rx descriptors
 * @rx_ring: Rx descriptor ring (for a specific queue) to setup
 *
 * Returns 0 on success, negative on failure
 **/
int i40e_setup_rx_descriptors(struct i40e_ring *rx_ring)
{}

/**
 * i40e_release_rx_desc - Store the new tail and head values
 * @rx_ring: ring to bump
 * @val: new head index
 **/
void i40e_release_rx_desc(struct i40e_ring *rx_ring, u32 val)
{}

#if (PAGE_SIZE >= 8192)
static unsigned int i40e_rx_frame_truesize(struct i40e_ring *rx_ring,
					   unsigned int size)
{
	unsigned int truesize;

	truesize = rx_ring->rx_offset ?
		SKB_DATA_ALIGN(size + rx_ring->rx_offset) +
		SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) :
		SKB_DATA_ALIGN(size);
	return truesize;
}
#endif

/**
 * i40e_alloc_mapped_page - recycle or make a new page
 * @rx_ring: ring to use
 * @bi: rx_buffer struct to modify
 *
 * Returns true if the page was successfully allocated or
 * reused.
 **/
static bool i40e_alloc_mapped_page(struct i40e_ring *rx_ring,
				   struct i40e_rx_buffer *bi)
{}

/**
 * i40e_alloc_rx_buffers - Replace used receive buffers
 * @rx_ring: ring to place buffers on
 * @cleaned_count: number of buffers to replace
 *
 * Returns false if all allocations were successful, true if any fail
 **/
bool i40e_alloc_rx_buffers(struct i40e_ring *rx_ring, u16 cleaned_count)
{}

/**
 * i40e_rx_checksum - Indicate in skb if hw indicated a good cksum
 * @vsi: the VSI we care about
 * @skb: skb currently being received and modified
 * @rx_desc: the receive descriptor
 **/
static inline void i40e_rx_checksum(struct i40e_vsi *vsi,
				    struct sk_buff *skb,
				    union i40e_rx_desc *rx_desc)
{}

/**
 * i40e_rx_hash - set the hash value in the skb
 * @ring: descriptor ring
 * @rx_desc: specific descriptor
 * @skb: skb currently being received and modified
 * @rx_ptype: Rx packet type
 **/
static inline void i40e_rx_hash(struct i40e_ring *ring,
				union i40e_rx_desc *rx_desc,
				struct sk_buff *skb,
				u8 rx_ptype)
{}

/**
 * i40e_process_skb_fields - Populate skb header fields from Rx descriptor
 * @rx_ring: rx descriptor ring packet is being transacted on
 * @rx_desc: pointer to the EOP Rx descriptor
 * @skb: pointer to current skb being populated
 *
 * This function checks the ring, descriptor, and packet information in
 * order to populate the hash, checksum, VLAN, protocol, and
 * other fields within the skb.
 **/
void i40e_process_skb_fields(struct i40e_ring *rx_ring,
			     union i40e_rx_desc *rx_desc, struct sk_buff *skb)
{}

/**
 * i40e_cleanup_headers - Correct empty headers
 * @rx_ring: rx descriptor ring packet is being transacted on
 * @skb: pointer to current skb being fixed
 * @rx_desc: pointer to the EOP Rx descriptor
 *
 * In addition if skb is not at least 60 bytes we need to pad it so that
 * it is large enough to qualify as a valid Ethernet frame.
 *
 * Returns true if an error was encountered and skb was freed.
 **/
static bool i40e_cleanup_headers(struct i40e_ring *rx_ring, struct sk_buff *skb,
				 union i40e_rx_desc *rx_desc)

{}

/**
 * i40e_can_reuse_rx_page - Determine if page can be reused for another Rx
 * @rx_buffer: buffer containing the page
 * @rx_stats: rx stats structure for the rx ring
 *
 * If page is reusable, we have a green light for calling i40e_reuse_rx_page,
 * which will assign the current buffer to the buffer that next_to_alloc is
 * pointing to; otherwise, the DMA mapping needs to be destroyed and
 * page freed.
 *
 * rx_stats will be updated to indicate whether the page was waived
 * or busy if it could not be reused.
 */
static bool i40e_can_reuse_rx_page(struct i40e_rx_buffer *rx_buffer,
				   struct i40e_rx_queue_stats *rx_stats)
{}

/**
 * i40e_rx_buffer_flip - adjusted rx_buffer to point to an unused region
 * @rx_buffer: Rx buffer to adjust
 * @truesize: Size of adjustment
 **/
static void i40e_rx_buffer_flip(struct i40e_rx_buffer *rx_buffer,
				unsigned int truesize)
{}

/**
 * i40e_get_rx_buffer - Fetch Rx buffer and synchronize data for use
 * @rx_ring: rx descriptor ring to transact packets on
 * @size: size of buffer to add to skb
 *
 * This function will pull an Rx buffer from the ring and synchronize it
 * for use by the CPU.
 */
static struct i40e_rx_buffer *i40e_get_rx_buffer(struct i40e_ring *rx_ring,
						 const unsigned int size)
{}

/**
 * i40e_put_rx_buffer - Clean up used buffer and either recycle or free
 * @rx_ring: rx descriptor ring to transact packets on
 * @rx_buffer: rx buffer to pull data from
 *
 * This function will clean up the contents of the rx_buffer.  It will
 * either recycle the buffer or unmap it and free the associated resources.
 */
static void i40e_put_rx_buffer(struct i40e_ring *rx_ring,
			       struct i40e_rx_buffer *rx_buffer)
{}

/**
 * i40e_process_rx_buffs- Processing of buffers post XDP prog or on error
 * @rx_ring: Rx descriptor ring to transact packets on
 * @xdp_res: Result of the XDP program
 * @xdp: xdp_buff pointing to the data
 **/
static void i40e_process_rx_buffs(struct i40e_ring *rx_ring, int xdp_res,
				  struct xdp_buff *xdp)
{}

/**
 * i40e_construct_skb - Allocate skb and populate it
 * @rx_ring: rx descriptor ring to transact packets on
 * @xdp: xdp_buff pointing to the data
 *
 * This function allocates an skb.  It then populates it with the page
 * data from the current receive descriptor, taking care to set up the
 * skb correctly.
 */
static struct sk_buff *i40e_construct_skb(struct i40e_ring *rx_ring,
					  struct xdp_buff *xdp)
{}

/**
 * i40e_build_skb - Build skb around an existing buffer
 * @rx_ring: Rx descriptor ring to transact packets on
 * @xdp: xdp_buff pointing to the data
 *
 * This function builds an skb around an existing Rx buffer, taking care
 * to set up the skb correctly and avoid any memcpy overhead.
 */
static struct sk_buff *i40e_build_skb(struct i40e_ring *rx_ring,
				      struct xdp_buff *xdp)
{}

/**
 * i40e_is_non_eop - process handling of non-EOP buffers
 * @rx_ring: Rx ring being processed
 * @rx_desc: Rx descriptor for current buffer
 *
 * If the buffer is an EOP buffer, this function exits returning false,
 * otherwise return true indicating that this is in fact a non-EOP buffer.
 */
bool i40e_is_non_eop(struct i40e_ring *rx_ring,
		     union i40e_rx_desc *rx_desc)
{}

static int i40e_xmit_xdp_ring(struct xdp_frame *xdpf,
			      struct i40e_ring *xdp_ring);

int i40e_xmit_xdp_tx_ring(struct xdp_buff *xdp, struct i40e_ring *xdp_ring)
{}

/**
 * i40e_run_xdp - run an XDP program
 * @rx_ring: Rx ring being processed
 * @xdp: XDP buffer containing the frame
 * @xdp_prog: XDP program to run
 **/
static int i40e_run_xdp(struct i40e_ring *rx_ring, struct xdp_buff *xdp, struct bpf_prog *xdp_prog)
{}

/**
 * i40e_xdp_ring_update_tail - Updates the XDP Tx ring tail register
 * @xdp_ring: XDP Tx ring
 *
 * This function updates the XDP Tx ring tail register.
 **/
void i40e_xdp_ring_update_tail(struct i40e_ring *xdp_ring)
{}

/**
 * i40e_update_rx_stats - Update Rx ring statistics
 * @rx_ring: rx descriptor ring
 * @total_rx_bytes: number of bytes received
 * @total_rx_packets: number of packets received
 *
 * This function updates the Rx ring statistics.
 **/
void i40e_update_rx_stats(struct i40e_ring *rx_ring,
			  unsigned int total_rx_bytes,
			  unsigned int total_rx_packets)
{}

/**
 * i40e_finalize_xdp_rx - Bump XDP Tx tail and/or flush redirect map
 * @rx_ring: Rx ring
 * @xdp_res: Result of the receive batch
 *
 * This function bumps XDP Tx tail and/or flush redirect map, and
 * should be called when a batch of packets has been processed in the
 * napi loop.
 **/
void i40e_finalize_xdp_rx(struct i40e_ring *rx_ring, unsigned int xdp_res)
{}

/**
 * i40e_inc_ntp: Advance the next_to_process index
 * @rx_ring: Rx ring
 **/
static void i40e_inc_ntp(struct i40e_ring *rx_ring)
{}

/**
 * i40e_add_xdp_frag: Add a frag to xdp_buff
 * @xdp: xdp_buff pointing to the data
 * @nr_frags: return number of buffers for the packet
 * @rx_buffer: rx_buffer holding data of the current frag
 * @size: size of data of current frag
 */
static int i40e_add_xdp_frag(struct xdp_buff *xdp, u32 *nr_frags,
			     struct i40e_rx_buffer *rx_buffer, u32 size)
{}

/**
 * i40e_consume_xdp_buff - Consume all the buffers of the packet and update ntc
 * @rx_ring: rx descriptor ring to transact packets on
 * @xdp: xdp_buff pointing to the data
 * @rx_buffer: rx_buffer of eop desc
 */
static void i40e_consume_xdp_buff(struct i40e_ring *rx_ring,
				  struct xdp_buff *xdp,
				  struct i40e_rx_buffer *rx_buffer)
{}

/**
 * i40e_clean_rx_irq - Clean completed descriptors from Rx ring - bounce buf
 * @rx_ring: rx descriptor ring to transact packets on
 * @budget: Total limit on number of packets to process
 * @rx_cleaned: Out parameter of the number of packets processed
 *
 * This function provides a "bounce buffer" approach to Rx interrupt
 * processing.  The advantage to this is that on systems that have
 * expensive overhead for IOMMU access this provides a means of avoiding
 * it by maintaining the mapping of the page to the system.
 *
 * Returns amount of work completed
 **/
static int i40e_clean_rx_irq(struct i40e_ring *rx_ring, int budget,
			     unsigned int *rx_cleaned)
{}

/**
 * i40e_buildreg_itr - build a value for writing to I40E_PFINT_DYN_CTLN register
 * @itr_idx: interrupt throttling index
 * @interval: interrupt throttling interval value in usecs
 * @force_swint: force software interrupt
 *
 * The function builds a value for I40E_PFINT_DYN_CTLN register that
 * is used to update interrupt throttling interval for specified ITR index
 * and optionally enforces a software interrupt. If the @itr_idx is equal
 * to I40E_ITR_NONE then no interval change is applied and only @force_swint
 * parameter is taken into account. If the interval change and enforced
 * software interrupt are not requested then the built value just enables
 * appropriate vector interrupt.
 **/
static u32 i40e_buildreg_itr(enum i40e_dyn_idx itr_idx, u16 interval,
			     bool force_swint)
{}

/* The act of updating the ITR will cause it to immediately trigger. In order
 * to prevent this from throwing off adaptive update statistics we defer the
 * update so that it can only happen so often. So after either Tx or Rx are
 * updated we make the adaptive scheme wait until either the ITR completely
 * expires via the next_update expiration or we have been through at least
 * 3 interrupts.
 */
#define ITR_COUNTDOWN_START

/**
 * i40e_update_enable_itr - Update itr and re-enable MSIX interrupt
 * @vsi: the VSI we care about
 * @q_vector: q_vector for which itr is being updated and interrupt enabled
 *
 **/
static inline void i40e_update_enable_itr(struct i40e_vsi *vsi,
					  struct i40e_q_vector *q_vector)
{}

/**
 * i40e_napi_poll - NAPI polling Rx/Tx cleanup routine
 * @napi: napi struct with our devices info in it
 * @budget: amount of work driver is allowed to do this pass, in packets
 *
 * This function will clean all queues associated with a q_vector.
 *
 * Returns the amount of work done
 **/
int i40e_napi_poll(struct napi_struct *napi, int budget)
{}

/**
 * i40e_atr - Add a Flow Director ATR filter
 * @tx_ring:  ring to add programming descriptor to
 * @skb:      send buffer
 * @tx_flags: send tx flags
 **/
static void i40e_atr(struct i40e_ring *tx_ring, struct sk_buff *skb,
		     u32 tx_flags)
{}

/**
 * i40e_tx_prepare_vlan_flags - prepare generic TX VLAN tagging flags for HW
 * @skb:     send buffer
 * @tx_ring: ring to send buffer on
 * @flags:   the tx flags to be set
 *
 * Checks the skb and set up correspondingly several generic transmit flags
 * related to VLAN tagging for the HW, such as VLAN, DCB, etc.
 *
 * Returns error code indicate the frame should be dropped upon error and the
 * otherwise  returns 0 to indicate the flags has been set properly.
 **/
static inline int i40e_tx_prepare_vlan_flags(struct sk_buff *skb,
					     struct i40e_ring *tx_ring,
					     u32 *flags)
{}

/**
 * i40e_tso - set up the tso context descriptor
 * @first:    pointer to first Tx buffer for xmit
 * @hdr_len:  ptr to the size of the packet header
 * @cd_type_cmd_tso_mss: Quad Word 1
 *
 * Returns 0 if no TSO can happen, 1 if tso is going, or error
 **/
static int i40e_tso(struct i40e_tx_buffer *first, u8 *hdr_len,
		    u64 *cd_type_cmd_tso_mss)
{}

/**
 * i40e_tsyn - set up the tsyn context descriptor
 * @tx_ring:  ptr to the ring to send
 * @skb:      ptr to the skb we're sending
 * @tx_flags: the collected send information
 * @cd_type_cmd_tso_mss: Quad Word 1
 *
 * Returns 0 if no Tx timestamp can happen and 1 if the timestamp will happen
 **/
static int i40e_tsyn(struct i40e_ring *tx_ring, struct sk_buff *skb,
		     u32 tx_flags, u64 *cd_type_cmd_tso_mss)
{}

/**
 * i40e_tx_enable_csum - Enable Tx checksum offloads
 * @skb: send buffer
 * @tx_flags: pointer to Tx flags currently set
 * @td_cmd: Tx descriptor command bits to set
 * @td_offset: Tx descriptor header offsets to set
 * @tx_ring: Tx descriptor ring
 * @cd_tunneling: ptr to context desc bits
 **/
static int i40e_tx_enable_csum(struct sk_buff *skb, u32 *tx_flags,
			       u32 *td_cmd, u32 *td_offset,
			       struct i40e_ring *tx_ring,
			       u32 *cd_tunneling)
{}

/**
 * i40e_create_tx_ctx - Build the Tx context descriptor
 * @tx_ring:  ring to create the descriptor on
 * @cd_type_cmd_tso_mss: Quad Word 1
 * @cd_tunneling: Quad Word 0 - bits 0-31
 * @cd_l2tag2: Quad Word 0 - bits 32-63
 **/
static void i40e_create_tx_ctx(struct i40e_ring *tx_ring,
			       const u64 cd_type_cmd_tso_mss,
			       const u32 cd_tunneling, const u32 cd_l2tag2)
{}

/**
 * __i40e_maybe_stop_tx - 2nd level check for tx stop conditions
 * @tx_ring: the ring to be checked
 * @size:    the size buffer we want to assure is available
 *
 * Returns -EBUSY if a stop is needed, else 0
 **/
int __i40e_maybe_stop_tx(struct i40e_ring *tx_ring, int size)
{}

/**
 * __i40e_chk_linearize - Check if there are more than 8 buffers per packet
 * @skb:      send buffer
 *
 * Note: Our HW can't DMA more than 8 buffers to build a packet on the wire
 * and so we need to figure out the cases where we need to linearize the skb.
 *
 * For TSO we need to count the TSO header and segment payload separately.
 * As such we need to check cases where we have 7 fragments or more as we
 * can potentially require 9 DMA transactions, 1 for the TSO header, 1 for
 * the segment payload in the first descriptor, and another 7 for the
 * fragments.
 **/
bool __i40e_chk_linearize(struct sk_buff *skb)
{}

/**
 * i40e_tx_map - Build the Tx descriptor
 * @tx_ring:  ring to send buffer on
 * @skb:      send buffer
 * @first:    first buffer info buffer to use
 * @tx_flags: collected send information
 * @hdr_len:  size of the packet header
 * @td_cmd:   the command field in the descriptor
 * @td_offset: offset for checksum or crc
 *
 * Returns 0 on success, -1 on failure to DMA
 **/
static inline int i40e_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb,
			      struct i40e_tx_buffer *first, u32 tx_flags,
			      const u8 hdr_len, u32 td_cmd, u32 td_offset)
{}

static u16 i40e_swdcb_skb_tx_hash(struct net_device *dev,
				  const struct sk_buff *skb,
				  u16 num_tx_queues)
{}

u16 i40e_lan_select_queue(struct net_device *netdev,
			  struct sk_buff *skb,
			  struct net_device __always_unused *sb_dev)
{}

/**
 * i40e_xmit_xdp_ring - transmits an XDP buffer to an XDP Tx ring
 * @xdpf: data to transmit
 * @xdp_ring: XDP Tx ring
 **/
static int i40e_xmit_xdp_ring(struct xdp_frame *xdpf,
			      struct i40e_ring *xdp_ring)
{}

/**
 * i40e_xmit_frame_ring - Sends buffer on Tx ring
 * @skb:     send buffer
 * @tx_ring: ring to send buffer on
 *
 * Returns NETDEV_TX_OK if sent, else an error code
 **/
static netdev_tx_t i40e_xmit_frame_ring(struct sk_buff *skb,
					struct i40e_ring *tx_ring)
{}

/**
 * i40e_lan_xmit_frame - Selects the correct VSI and Tx queue to send buffer
 * @skb:    send buffer
 * @netdev: network interface device structure
 *
 * Returns NETDEV_TX_OK if sent, else an error code
 **/
netdev_tx_t i40e_lan_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
{}

/**
 * i40e_xdp_xmit - Implements ndo_xdp_xmit
 * @dev: netdev
 * @n: number of frames
 * @frames: array of XDP buffer pointers
 * @flags: XDP extra info
 *
 * Returns number of frames successfully sent. Failed frames
 * will be free'ed by XDP core.
 *
 * For error cases, a negative errno code is returned and no-frames
 * are transmitted (caller must handle freeing frames).
 **/
int i40e_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **frames,
		  u32 flags)
{}