diff options
Diffstat (limited to 'drivers/net/ethernet/google/gve/gve_desc_dqo.h')
| -rw-r--r-- | drivers/net/ethernet/google/gve/gve_desc_dqo.h | 256 |
1 files changed, 256 insertions, 0 deletions
diff --git a/drivers/net/ethernet/google/gve/gve_desc_dqo.h b/drivers/net/ethernet/google/gve/gve_desc_dqo.h new file mode 100644 index 000000000000..e8fe9adef7f2 --- /dev/null +++ b/drivers/net/ethernet/google/gve/gve_desc_dqo.h @@ -0,0 +1,256 @@ +/* SPDX-License-Identifier: (GPL-2.0 OR MIT) + * Google virtual Ethernet (gve) driver + * + * Copyright (C) 2015-2021 Google, Inc. + */ + +/* GVE DQO Descriptor formats */ + +#ifndef _GVE_DESC_DQO_H_ +#define _GVE_DESC_DQO_H_ + +#include <linux/build_bug.h> + +#define GVE_TX_MAX_HDR_SIZE_DQO 255 +#define GVE_TX_MIN_TSO_MSS_DQO 88 + +#ifndef __LITTLE_ENDIAN_BITFIELD +#error "Only little endian supported" +#endif + +/* Basic TX descriptor (DTYPE 0x0C) */ +struct gve_tx_pkt_desc_dqo { + __le64 buf_addr; + + /* Must be GVE_TX_PKT_DESC_DTYPE_DQO (0xc) */ + u8 dtype: 5; + + /* Denotes the last descriptor of a packet. */ + u8 end_of_packet: 1; + u8 checksum_offload_enable: 1; + + /* If set, will generate a descriptor completion for this descriptor. */ + u8 report_event: 1; + u8 reserved0; + __le16 reserved1; + + /* The TX completion associated with this packet will contain this tag. + */ + __le16 compl_tag; + u16 buf_size: 14; + u16 reserved2: 2; +} __packed; +static_assert(sizeof(struct gve_tx_pkt_desc_dqo) == 16); + +#define GVE_TX_PKT_DESC_DTYPE_DQO 0xc +#define GVE_TX_MAX_BUF_SIZE_DQO ((16 * 1024) - 1) + +/* Maximum number of data descriptors allowed per packet, or per-TSO segment. */ +#define GVE_TX_MAX_DATA_DESCS 10 + +/* Min gap between tail and head to avoid cacheline overlap */ +#define GVE_TX_MIN_DESC_PREVENT_CACHE_OVERLAP 4 + +/* "report_event" on TX packet descriptors may only be reported on the last + * descriptor of a TX packet, and they must be spaced apart with at least this + * value. + */ +#define GVE_TX_MIN_RE_INTERVAL 32 + +struct gve_tx_context_cmd_dtype { + u8 dtype: 5; + u8 tso: 1; + u8 reserved1: 2; + + u8 reserved2; +}; + +static_assert(sizeof(struct gve_tx_context_cmd_dtype) == 2); + +/* TX Native TSO Context DTYPE (0x05) + * + * "flex" fields allow the driver to send additional packet context to HW. + */ +struct gve_tx_tso_context_desc_dqo { + /* The L4 payload bytes that should be segmented. */ + u32 tso_total_len: 24; + u32 flex10: 8; + + /* Max segment size in TSO excluding headers. */ + u16 mss: 14; + u16 reserved: 2; + + u8 header_len; /* Header length to use for TSO offload */ + u8 flex11; + struct gve_tx_context_cmd_dtype cmd_dtype; + u8 flex0; + u8 flex5; + u8 flex6; + u8 flex7; + u8 flex8; + u8 flex9; +} __packed; +static_assert(sizeof(struct gve_tx_tso_context_desc_dqo) == 16); + +#define GVE_TX_TSO_CTX_DESC_DTYPE_DQO 0x5 + +/* General context descriptor for sending metadata. */ +struct gve_tx_general_context_desc_dqo { + u8 flex4; + u8 flex5; + u8 flex6; + u8 flex7; + u8 flex8; + u8 flex9; + u8 flex10; + u8 flex11; + struct gve_tx_context_cmd_dtype cmd_dtype; + u16 reserved; + u8 flex0; + u8 flex1; + u8 flex2; + u8 flex3; +} __packed; +static_assert(sizeof(struct gve_tx_general_context_desc_dqo) == 16); + +#define GVE_TX_GENERAL_CTX_DESC_DTYPE_DQO 0x4 + +/* Logical structure of metadata which is packed into context descriptor flex + * fields. + */ +struct gve_tx_metadata_dqo { + union { + struct { + u8 version; + + /* If `skb->l4_hash` is set, this value should be + * derived from `skb->hash`. + * + * A zero value means no l4_hash was associated with the + * skb. + */ + u16 path_hash: 15; + + /* Should be set to 1 if the flow associated with the + * skb had a rehash from the TCP stack. + */ + u16 rehash_event: 1; + } __packed; + u8 bytes[12]; + }; +} __packed; +static_assert(sizeof(struct gve_tx_metadata_dqo) == 12); + +#define GVE_TX_METADATA_VERSION_DQO 0 + +/* TX completion descriptor */ +struct gve_tx_compl_desc { + /* For types 0-4 this is the TX queue ID associated with this + * completion. + */ + u16 id: 11; + + /* See: GVE_COMPL_TYPE_DQO* */ + u16 type: 3; + u16 reserved0: 1; + + /* Flipped by HW to notify the descriptor is populated. */ + u16 generation: 1; + union { + /* For descriptor completions, this is the last index fetched + * by HW + 1. + */ + __le16 tx_head; + + /* For packet completions, this is the completion tag set on the + * TX packet descriptors. + */ + __le16 completion_tag; + }; + __le32 reserved1; +} __packed; +static_assert(sizeof(struct gve_tx_compl_desc) == 8); + +#define GVE_COMPL_TYPE_DQO_PKT 0x2 /* Packet completion */ +#define GVE_COMPL_TYPE_DQO_DESC 0x4 /* Descriptor completion */ +#define GVE_COMPL_TYPE_DQO_MISS 0x1 /* Miss path completion */ +#define GVE_COMPL_TYPE_DQO_REINJECTION 0x3 /* Re-injection completion */ + +/* Descriptor to post buffers to HW on buffer queue. */ +struct gve_rx_desc_dqo { + __le16 buf_id; /* ID returned in Rx completion descriptor */ + __le16 reserved0; + __le32 reserved1; + __le64 buf_addr; /* DMA address of the buffer */ + __le64 header_buf_addr; + __le64 reserved2; +} __packed; +static_assert(sizeof(struct gve_rx_desc_dqo) == 32); + +/* Descriptor for HW to notify SW of new packets received on RX queue. */ +struct gve_rx_compl_desc_dqo { + /* Must be 1 */ + u8 rxdid: 4; + u8 reserved0: 4; + + /* Packet originated from this system rather than the network. */ + u8 loopback: 1; + /* Set when IPv6 packet contains a destination options header or routing + * header. + */ + u8 ipv6_ex_add: 1; + /* Invalid packet was received. */ + u8 rx_error: 1; + u8 reserved1: 5; + + u16 packet_type: 10; + u16 ip_hdr_err: 1; + u16 udp_len_err: 1; + u16 raw_cs_invalid: 1; + u16 reserved2: 3; + + u16 packet_len: 14; + /* Flipped by HW to notify the descriptor is populated. */ + u16 generation: 1; + /* Should be zero. */ + u16 buffer_queue_id: 1; + + u16 header_len: 10; + u16 rsc: 1; + u16 split_header: 1; + u16 reserved3: 4; + + u8 descriptor_done: 1; + u8 end_of_packet: 1; + u8 header_buffer_overflow: 1; + u8 l3_l4_processed: 1; + u8 csum_ip_err: 1; + u8 csum_l4_err: 1; + u8 csum_external_ip_err: 1; + u8 csum_external_udp_err: 1; + + u8 status_error1; + + __le16 reserved5; + __le16 buf_id; /* Buffer ID which was sent on the buffer queue. */ + + union { + /* Packet checksum. */ + __le16 raw_cs; + /* Segment length for RSC packets. */ + __le16 rsc_seg_len; + }; + __le32 hash; + __le32 reserved6; + __le64 reserved7; +} __packed; + +static_assert(sizeof(struct gve_rx_compl_desc_dqo) == 32); + +/* Ringing the doorbell too often can hurt performance. + * + * HW requires this value to be at least 8. + */ +#define GVE_RX_BUF_THRESH_DQO 32 + +#endif /* _GVE_DESC_DQO_H_ */ |