diff options
Diffstat (limited to 'drivers/net/ethernet/google/gve/gve_desc.h')
| -rw-r--r-- | drivers/net/ethernet/google/gve/gve_desc.h | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/drivers/net/ethernet/google/gve/gve_desc.h b/drivers/net/ethernet/google/gve/gve_desc.h new file mode 100644 index 000000000000..54779871d52e --- /dev/null +++ b/drivers/net/ethernet/google/gve/gve_desc.h @@ -0,0 +1,113 @@ +/* SPDX-License-Identifier: (GPL-2.0 OR MIT) + * Google virtual Ethernet (gve) driver + * + * Copyright (C) 2015-2019 Google, Inc. + */ + +/* GVE Transmit Descriptor formats */ + +#ifndef _GVE_DESC_H_ +#define _GVE_DESC_H_ + +#include <linux/build_bug.h> + +/* A note on seg_addrs + * + * Base addresses encoded in seg_addr are not assumed to be physical + * addresses. The ring format assumes these come from some linear address + * space. This could be physical memory, kernel virtual memory, user virtual + * memory. gVNIC uses lists of registered pages. Each queue is assumed + * to be associated with a single such linear address space to ensure a + * consistent meaning for seg_addrs posted to its rings. + */ + +struct gve_tx_pkt_desc { + u8 type_flags; /* desc type is lower 4 bits, flags upper */ + u8 l4_csum_offset; /* relative offset of L4 csum word */ + u8 l4_hdr_offset; /* Offset of start of L4 headers in packet */ + u8 desc_cnt; /* Total descriptors for this packet */ + __be16 len; /* Total length of this packet (in bytes) */ + __be16 seg_len; /* Length of this descriptor's segment */ + __be64 seg_addr; /* Base address (see note) of this segment */ +} __packed; + +struct gve_tx_seg_desc { + u8 type_flags; /* type is lower 4 bits, flags upper */ + u8 l3_offset; /* TSO: 2 byte units to start of IPH */ + __be16 reserved; + __be16 mss; /* TSO MSS */ + __be16 seg_len; + __be64 seg_addr; +} __packed; + +/* GVE Transmit Descriptor Types */ +#define GVE_TXD_STD (0x0 << 4) /* Std with Host Address */ +#define GVE_TXD_TSO (0x1 << 4) /* TSO with Host Address */ +#define GVE_TXD_SEG (0x2 << 4) /* Seg with Host Address */ + +/* GVE Transmit Descriptor Flags for Std Pkts */ +#define GVE_TXF_L4CSUM BIT(0) /* Need csum offload */ +#define GVE_TXF_TSTAMP BIT(2) /* Timestamp required */ + +/* GVE Transmit Descriptor Flags for TSO Segs */ +#define GVE_TXSF_IPV6 BIT(1) /* IPv6 TSO */ + +/* GVE Receive Packet Descriptor */ +/* The start of an ethernet packet comes 2 bytes into the rx buffer. + * gVNIC adds this padding so that both the DMA and the L3/4 protocol header + * access is aligned. + */ +#define GVE_RX_PAD 2 + +struct gve_rx_desc { + u8 padding[48]; + __be32 rss_hash; /* Receive-side scaling hash (Toeplitz for gVNIC) */ + __be16 mss; + __be16 reserved; /* Reserved to zero */ + u8 hdr_len; /* Header length (L2-L4) including padding */ + u8 hdr_off; /* 64-byte-scaled offset into RX_DATA entry */ + __sum16 csum; /* 1's-complement partial checksum of L3+ bytes */ + __be16 len; /* Length of the received packet */ + __be16 flags_seq; /* Flags [15:3] and sequence number [2:0] (1-7) */ +} __packed; +static_assert(sizeof(struct gve_rx_desc) == 64); + +/* As with the Tx ring format, the qpl_offset entries below are offsets into an + * ordered list of registered pages. + */ +struct gve_rx_data_slot { + /* byte offset into the rx registered segment of this slot */ + __be64 qpl_offset; +}; + +/* GVE Recive Packet Descriptor Seq No */ +#define GVE_SEQNO(x) (be16_to_cpu(x) & 0x7) + +/* GVE Recive Packet Descriptor Flags */ +#define GVE_RXFLG(x) cpu_to_be16(1 << (3 + (x))) +#define GVE_RXF_FRAG GVE_RXFLG(3) /* IP Fragment */ +#define GVE_RXF_IPV4 GVE_RXFLG(4) /* IPv4 */ +#define GVE_RXF_IPV6 GVE_RXFLG(5) /* IPv6 */ +#define GVE_RXF_TCP GVE_RXFLG(6) /* TCP Packet */ +#define GVE_RXF_UDP GVE_RXFLG(7) /* UDP Packet */ +#define GVE_RXF_ERR GVE_RXFLG(8) /* Packet Error Detected */ + +/* GVE IRQ */ +#define GVE_IRQ_ACK BIT(31) +#define GVE_IRQ_MASK BIT(30) +#define GVE_IRQ_EVENT BIT(29) + +static inline bool gve_needs_rss(__be16 flag) +{ + if (flag & GVE_RXF_FRAG) + return false; + if (flag & (GVE_RXF_IPV4 | GVE_RXF_IPV6)) + return true; + return false; +} + +static inline u8 gve_next_seqno(u8 seq) +{ + return (seq + 1) == 8 ? 1 : seq + 1; +} +#endif /* _GVE_DESC_H_ */ |