freebsd-skq/sys/net/iflib.h
Matt Macy 81be655266 iflib: ensure that tx interrupts enabled and cleanups
Doing a 'dd' over iscsi will reliably cause stalls. Tx
cleaning _should_ reliably happen as data is sent.
However, currently if the transmit queue fills it will
wait until the iflib timer (hz/2) runs.

This change causes the the tx taskq thread to be run
if there are completed descriptors.

While here:

- make timer interrupt delay a sysctl

- simplify txd_db_check handling

- comment on INTR types

Background on the change:

Initially doorbell updates were minimized by only writing to the register
on every fourth packet. If txq_drain would return without writing to the
doorbell it scheduled a callout on the next tick to do the doorbell write
to ensure that the write otherwise happened "soon". At that time a sysctl
was added for users to avoid the potential added latency by simply writing
to the doorbell register on every packet. This worked perfectly well for
e1000 and ixgbe ... and appeared to work well on ixl. However, as it
turned out there was a race to this approach that would lockup the ixl MAC.
It was possible for a lower producer index to be written after a higher one.
On e1000 and ixgbe this was harmless - on ixl it was fatal. My initial
response was to add a lock around doorbell writes - fixing the problem but
adding an unacceptable amount of lock contention.

The next iteration was to use transmit interrupts to drive delayed doorbell
writes. If there were no packets in the queue all doorbell writes would be
immediate as the queue started to fill up we could delay doorbell writes
further and further. At the start of drain if we've cleaned any packets we
know we've moved the state machine along and we write the doorbell (an
obvious missing optimization was to skip that doorbell write if db_pending
is zero). This change required that tx interrupts be scheduled periodically
as opposed to just when the hardware txq was full. However, that just leads
to our next problem.

Initially dedicated msix vectors were used for both tx and rx. However, it
was often possible to use up all available vectors before we set up all the
queues we wanted. By having rx and tx share a vector for a given queue we
could halve the number of vectors used by a given configuration. The problem
here is that with this change only e1000 passed the necessary value to have
the fast interrupt drive tx when appropriate.

Reported by: mav@
Tested by: mav@
Reviewed by:    gallatin@
MFC after:      1 month
Sponsored by:   iXsystems
Differential Revision:  https://reviews.freebsd.org/D27683
2021-01-07 14:07:35 -08:00

499 lines
14 KiB
C

/*-
* Copyright (c) 2014-2017, Matthew Macy (mmacy@mattmacy.io)
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. Neither the name of Matthew Macy nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef __IFLIB_H_
#define __IFLIB_H_
#include <sys/kobj.h>
#include <sys/bus.h>
#include <sys/cpuset.h>
#include <machine/bus.h>
#include <sys/nv.h>
#include <sys/gtaskqueue.h>
struct if_clone;
/*
* The value type for indexing, limits max descriptors
* to 65535 can be conditionally redefined to uint32_t
* in the future if the need arises.
*/
typedef uint16_t qidx_t;
#define QIDX_INVALID 0xFFFF
struct iflib_ctx;
typedef struct iflib_ctx *if_ctx_t;
struct if_shared_ctx;
typedef struct if_shared_ctx *if_shared_ctx_t;
struct if_int_delay_info;
typedef struct if_int_delay_info *if_int_delay_info_t;
struct if_pseudo;
typedef struct if_pseudo *if_pseudo_t;
/*
* File organization:
* - public structures
* - iflib accessors
* - iflib utility functions
* - iflib core functions
*/
typedef struct if_rxd_frag {
uint8_t irf_flid;
qidx_t irf_idx;
uint16_t irf_len;
} *if_rxd_frag_t;
/* bnxt supports 64 with hardware LRO enabled */
#define IFLIB_MAX_RX_SEGS 64
typedef struct if_rxd_info {
/* set by iflib */
uint16_t iri_qsidx; /* qset index */
uint16_t iri_vtag; /* vlan tag - if flag set */
/* XXX redundant with the new irf_len field */
uint16_t iri_len; /* packet length */
qidx_t iri_cidx; /* consumer index of cq */
if_t iri_ifp; /* driver may have >1 iface per softc */
/* updated by driver */
if_rxd_frag_t iri_frags;
uint32_t iri_flowid; /* RSS hash for packet */
uint32_t iri_csum_flags; /* m_pkthdr csum flags */
uint32_t iri_csum_data; /* m_pkthdr csum data */
uint8_t iri_flags; /* mbuf flags for packet */
uint8_t iri_nfrags; /* number of fragments in packet */
uint8_t iri_rsstype; /* RSS hash type */
uint8_t iri_pad; /* any padding in the received data */
} *if_rxd_info_t;
typedef struct if_rxd_update {
uint64_t *iru_paddrs;
qidx_t *iru_idxs;
qidx_t iru_pidx;
uint16_t iru_qsidx;
uint16_t iru_count;
uint16_t iru_buf_size;
uint8_t iru_flidx;
} *if_rxd_update_t;
#define IPI_TX_INTR 0x1 /* send an interrupt when this packet is sent */
#define IPI_TX_IPV4 0x2 /* ethertype IPv4 */
#define IPI_TX_IPV6 0x4 /* ethertype IPv6 */
typedef struct if_pkt_info {
bus_dma_segment_t *ipi_segs; /* physical addresses */
uint32_t ipi_len; /* packet length */
uint16_t ipi_qsidx; /* queue set index */
qidx_t ipi_nsegs; /* number of segments */
qidx_t ipi_ndescs; /* number of descriptors used by encap */
uint16_t ipi_flags; /* iflib per-packet flags */
qidx_t ipi_pidx; /* start pidx for encap */
qidx_t ipi_new_pidx; /* next available pidx post-encap */
/* offload handling */
uint8_t ipi_ehdrlen; /* ether header length */
uint8_t ipi_ip_hlen; /* ip header length */
uint8_t ipi_tcp_hlen; /* tcp header length */
uint8_t ipi_ipproto; /* ip protocol */
uint32_t ipi_csum_flags; /* packet checksum flags */
uint16_t ipi_tso_segsz; /* tso segment size */
uint16_t ipi_vtag; /* VLAN tag */
uint16_t ipi_etype; /* ether header type */
uint8_t ipi_tcp_hflags; /* tcp header flags */
uint8_t ipi_mflags; /* packet mbuf flags */
uint32_t ipi_tcp_seq; /* tcp seqno */
uint32_t __spare0__;
} *if_pkt_info_t;
typedef struct if_irq {
struct resource *ii_res;
int __spare0__;
void *ii_tag;
} *if_irq_t;
struct if_int_delay_info {
if_ctx_t iidi_ctx; /* Back-pointer to the iflib ctx (softc) */
int iidi_offset; /* Register offset to read/write */
int iidi_value; /* Current value in usecs */
struct sysctl_oid *iidi_oidp;
struct sysctl_req *iidi_req;
};
typedef enum {
IFLIB_INTR_LEGACY,
IFLIB_INTR_MSI,
IFLIB_INTR_MSIX
} iflib_intr_mode_t;
/*
* This really belongs in pciio.h or some place more general
* but this is the only consumer for now.
*/
typedef struct pci_vendor_info {
uint32_t pvi_vendor_id;
uint32_t pvi_device_id;
uint32_t pvi_subvendor_id;
uint32_t pvi_subdevice_id;
uint32_t pvi_rev_id;
uint32_t pvi_class_mask;
const char *pvi_name;
} pci_vendor_info_t;
#define PVID(vendor, devid, name) {vendor, devid, 0, 0, 0, 0, name}
#define PVID_OEM(vendor, devid, svid, sdevid, revid, name) {vendor, devid, svid, sdevid, revid, 0, name}
#define PVID_END {0, 0, 0, 0, 0, 0, NULL}
/* No drivers in tree currently match on anything except vendor:device. */
#define IFLIB_PNP_DESCR "U32:vendor;U32:device;U32:#;U32:#;" \
"U32:#;U32:#;D:#"
#define IFLIB_PNP_INFO(b, u, t) \
MODULE_PNP_INFO(IFLIB_PNP_DESCR, b, u, t, nitems(t) - 1)
typedef struct if_txrx {
int (*ift_txd_encap) (void *, if_pkt_info_t);
void (*ift_txd_flush) (void *, uint16_t, qidx_t pidx);
int (*ift_txd_credits_update) (void *, uint16_t qsidx, bool clear);
int (*ift_rxd_available) (void *, uint16_t qsidx, qidx_t pidx, qidx_t budget);
int (*ift_rxd_pkt_get) (void *, if_rxd_info_t ri);
void (*ift_rxd_refill) (void * , if_rxd_update_t iru);
void (*ift_rxd_flush) (void *, uint16_t qsidx, uint8_t flidx, qidx_t pidx);
int (*ift_legacy_intr) (void *);
} *if_txrx_t;
typedef struct if_softc_ctx {
int isc_vectors;
int isc_nrxqsets;
int isc_ntxqsets;
uint16_t __spare0__;
uint32_t __spare1__;
int isc_msix_bar; /* can be model specific - initialize in attach_pre */
int isc_tx_nsegments; /* can be model specific - initialize in attach_pre */
int isc_ntxd[8];
int isc_nrxd[8];
uint32_t isc_txqsizes[8];
uint32_t isc_rxqsizes[8];
/* is there such thing as a descriptor that is more than 248 bytes ? */
uint8_t isc_txd_size[8];
uint8_t isc_rxd_size[8];
int isc_tx_tso_segments_max;
int isc_tx_tso_size_max;
int isc_tx_tso_segsize_max;
int isc_tx_csum_flags;
int isc_capabilities;
int isc_capenable;
int isc_rss_table_size;
int isc_rss_table_mask;
int isc_nrxqsets_max;
int isc_ntxqsets_max;
uint32_t __spare2__;
iflib_intr_mode_t isc_intr;
uint16_t isc_rxd_buf_size[8]; /* set at init time by driver, 0
means use iflib-calculated size
based on isc_max_frame_size */
uint16_t isc_max_frame_size; /* set at init time by driver */
uint16_t isc_min_frame_size; /* set at init time by driver, only used if
IFLIB_NEED_ETHER_PAD is set. */
uint32_t isc_pause_frames; /* set by driver for iflib_timer to detect */
uint32_t __spare3__;
uint32_t __spare4__;
uint32_t __spare5__;
uint32_t __spare6__;
uint32_t __spare7__;
uint32_t __spare8__;
caddr_t __spare9__;
int isc_disable_msix;
if_txrx_t isc_txrx;
struct ifmedia *isc_media;
} *if_softc_ctx_t;
/*
* Initialization values for device
*/
struct if_shared_ctx {
unsigned isc_magic;
driver_t *isc_driver;
bus_size_t isc_q_align;
bus_size_t isc_tx_maxsize;
bus_size_t isc_tx_maxsegsize;
bus_size_t isc_tso_maxsize;
bus_size_t isc_tso_maxsegsize;
bus_size_t isc_rx_maxsize;
bus_size_t isc_rx_maxsegsize;
int isc_rx_nsegments;
int isc_admin_intrcnt; /* # of admin/link interrupts */
/* fields necessary for probe */
const pci_vendor_info_t *isc_vendor_info;
const char *isc_driver_version;
/* optional function to transform the read values to match the table*/
void (*isc_parse_devinfo) (uint16_t *device_id, uint16_t *subvendor_id,
uint16_t *subdevice_id, uint16_t *rev_id);
int isc_nrxd_min[8];
int isc_nrxd_default[8];
int isc_nrxd_max[8];
int isc_ntxd_min[8];
int isc_ntxd_default[8];
int isc_ntxd_max[8];
/* actively used during operation */
int isc_nfl __aligned(CACHE_LINE_SIZE);
int isc_ntxqs; /* # of tx queues per tx qset - usually 1 */
int isc_nrxqs; /* # of rx queues per rx qset - intel 1, chelsio 2, broadcom 3 */
int __spare0__;
int isc_tx_reclaim_thresh;
int isc_flags;
const char *isc_name;
};
typedef struct iflib_dma_info {
bus_addr_t idi_paddr;
caddr_t idi_vaddr;
bus_dma_tag_t idi_tag;
bus_dmamap_t idi_map;
uint32_t idi_size;
} *iflib_dma_info_t;
#define IFLIB_MAGIC 0xCAFEF00D
typedef enum {
/* Interrupt or softirq handles only receive */
IFLIB_INTR_RX,
/* Interrupt or softirq handles only transmit */
IFLIB_INTR_TX,
/*
* Interrupt will check for both pending receive
* and available tx credits and dispatch a task
* for one or both depending on the disposition
* of the respective queues.
*/
IFLIB_INTR_RXTX,
/*
* Other interrupt - typically link status and
* or error conditions.
*/
IFLIB_INTR_ADMIN,
/* Softirq (task) for iov handling */
IFLIB_INTR_IOV,
} iflib_intr_type_t;
/*
* Interface has a separate completion queue for RX
*/
#define IFLIB_HAS_RXCQ 0x01
/*
* Driver has already allocated vectors
*/
#define IFLIB_SKIP_MSIX 0x02
/*
* Interface is a virtual function
*/
#define IFLIB_IS_VF 0x04
/*
* Interface has a separate completion queue for TX
*/
#define IFLIB_HAS_TXCQ 0x08
/*
* Interface does checksum in place
*/
#define IFLIB_NEED_SCRATCH 0x10
/*
* Interface doesn't expect in_pseudo for th_sum
*/
#define IFLIB_TSO_INIT_IP 0x20
/*
* Interface doesn't align IP header
*/
#define IFLIB_DO_RX_FIXUP 0x40
/*
* Driver needs csum zeroed for offloading
*/
#define IFLIB_NEED_ZERO_CSUM 0x80
/*
* Driver needs frames padded to some minimum length
*/
#define IFLIB_NEED_ETHER_PAD 0x100
/*
* Packets can be freed immediately after encap
*/
#define IFLIB_TXD_ENCAP_PIO 0x00200
/*
* Use RX completion handler
*/
#define IFLIB_RX_COMPLETION 0x00400
/*
* Skip refilling cluster free lists
*/
#define IFLIB_SKIP_CLREFILL 0x00800
/*
* Don't reset on hang
*/
#define IFLIB_NO_HANG_RESET 0x01000
/*
* Don't need/want most of the niceties of
* queue management
*/
#define IFLIB_PSEUDO 0x02000
/*
* No DMA support needed / wanted
*/
#define IFLIB_VIRTUAL 0x04000
/*
* autogenerate a MAC address
*/
#define IFLIB_GEN_MAC 0x08000
/*
* Interface needs admin task to ignore interface up/down status
*/
#define IFLIB_ADMIN_ALWAYS_RUN 0x10000
/*
* Driver will pass the media
*/
#define IFLIB_DRIVER_MEDIA 0x20000
/*
* When using a single hardware interrupt for the interface, only process RX
* interrupts instead of doing combined RX/TX processing.
*/
#define IFLIB_SINGLE_IRQ_RX_ONLY 0x40000
/*
* Don't need/want most of the niceties of
* emulating ethernet
*/
#define IFLIB_PSEUDO_ETHER 0x80000
/*
* These enum values are used in iflib_needs_restart to indicate to iflib
* functions whether or not the interface needs restarting when certain events
* happen.
*/
enum iflib_restart_event {
IFLIB_RESTART_VLAN_CONFIG,
};
/*
* field accessors
*/
void *iflib_get_softc(if_ctx_t ctx);
device_t iflib_get_dev(if_ctx_t ctx);
if_t iflib_get_ifp(if_ctx_t ctx);
struct ifmedia *iflib_get_media(if_ctx_t ctx);
if_softc_ctx_t iflib_get_softc_ctx(if_ctx_t ctx);
if_shared_ctx_t iflib_get_sctx(if_ctx_t ctx);
void iflib_set_mac(if_ctx_t ctx, uint8_t mac[ETHER_ADDR_LEN]);
void iflib_request_reset(if_ctx_t ctx);
uint8_t iflib_in_detach(if_ctx_t ctx);
uint32_t iflib_get_rx_mbuf_sz(if_ctx_t ctx);
/*
* If the driver can plug cleanly in to newbus use these
*/
int iflib_device_probe(device_t);
int iflib_device_attach(device_t);
int iflib_device_detach(device_t);
int iflib_device_suspend(device_t);
int iflib_device_resume(device_t);
int iflib_device_shutdown(device_t);
/*
* Use this instead of iflib_device_probe if the driver should report
* BUS_PROBE_VENDOR instead of BUS_PROBE_DEFAULT. (For example, an out-of-tree
* driver based on iflib).
*/
int iflib_device_probe_vendor(device_t);
int iflib_device_iov_init(device_t, uint16_t, const nvlist_t *);
void iflib_device_iov_uninit(device_t);
int iflib_device_iov_add_vf(device_t, uint16_t, const nvlist_t *);
/*
* If the driver can't plug cleanly in to newbus
* use these
*/
int iflib_device_register(device_t dev, void *softc, if_shared_ctx_t sctx, if_ctx_t *ctxp);
int iflib_device_deregister(if_ctx_t);
int iflib_irq_alloc(if_ctx_t, if_irq_t, int, driver_filter_t, void *filter_arg, driver_intr_t, void *arg, const char *name);
int iflib_irq_alloc_generic(if_ctx_t ctx, if_irq_t irq, int rid,
iflib_intr_type_t type, driver_filter_t *filter,
void *filter_arg, int qid, const char *name);
void iflib_softirq_alloc_generic(if_ctx_t ctx, if_irq_t irq, iflib_intr_type_t type, void *arg, int qid, const char *name);
void iflib_irq_free(if_ctx_t ctx, if_irq_t irq);
void iflib_io_tqg_attach(struct grouptask *gt, void *uniq, int cpu,
const char *name);
void iflib_config_gtask_init(void *ctx, struct grouptask *gtask,
gtask_fn_t *fn, const char *name);
void iflib_config_gtask_deinit(struct grouptask *gtask);
void iflib_tx_intr_deferred(if_ctx_t ctx, int txqid);
void iflib_rx_intr_deferred(if_ctx_t ctx, int rxqid);
void iflib_admin_intr_deferred(if_ctx_t ctx);
void iflib_iov_intr_deferred(if_ctx_t ctx);
void iflib_link_state_change(if_ctx_t ctx, int linkstate, uint64_t baudrate);
int iflib_dma_alloc(if_ctx_t ctx, int size, iflib_dma_info_t dma, int mapflags);
int iflib_dma_alloc_align(if_ctx_t ctx, int size, int align, iflib_dma_info_t dma, int mapflags);
void iflib_dma_free(iflib_dma_info_t dma);
int iflib_dma_alloc_multi(if_ctx_t ctx, int *sizes, iflib_dma_info_t *dmalist, int mapflags, int count);
void iflib_dma_free_multi(iflib_dma_info_t *dmalist, int count);
struct sx *iflib_ctx_lock_get(if_ctx_t);
void iflib_led_create(if_ctx_t ctx);
void iflib_add_int_delay_sysctl(if_ctx_t, const char *, const char *,
if_int_delay_info_t, int, int);
/*
* Pseudo device support
*/
if_pseudo_t iflib_clone_register(if_shared_ctx_t);
void iflib_clone_deregister(if_pseudo_t);
#endif /* __IFLIB_H_ */