1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 2023 Google LLC 5 * 6 * Redistribution and use in source and binary forms, with or without modification, 7 * are permitted provided that the following conditions are met: 8 * 9 * 1. Redistributions of source code must retain the above copyright notice, this 10 * list of conditions and the following disclaimer. 11 * 12 * 2. Redistributions in binary form must reproduce the above copyright notice, 13 * this list of conditions and the following disclaimer in the documentation 14 * and/or other materials provided with the distribution. 15 * 16 * 3. Neither the name of the copyright holder nor the names of its contributors 17 * may be used to endorse or promote products derived from this software without 18 * specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 22 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 23 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR 24 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 25 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 26 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON 27 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 29 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 */ 31 #ifndef _GVE_DESC_H_ 32 #define _GVE_DESC_H_ 33 34 #include "gve_plat.h" 35 36 /* 37 * A note on seg_addrs 38 * 39 * Base addresses encoded in seg_addr are not assumed to be physical 40 * addresses. The ring format assumes these come from some linear address 41 * space. This could be physical memory, kernel virtual memory, user virtual 42 * memory. 43 * 44 * Each queue is assumed to be associated with a single such linear 45 * address space to ensure a consistent meaning for seg_addrs posted to its 46 * rings. 47 */ 48 struct gve_tx_pkt_desc { 49 uint8_t type_flags; /* desc type is lower 4 bits, flags upper */ 50 uint8_t l4_csum_offset; /* relative offset of L4 csum word */ 51 uint8_t l4_hdr_offset; /* Offset of start of L4 headers in packet */ 52 uint8_t desc_cnt; /* Total descriptors for this packet */ 53 __be16 len; /* Total length of this packet (in bytes) */ 54 __be16 seg_len; /* Length of this descriptor's segment */ 55 __be64 seg_addr; /* Base address (see note) of this segment */ 56 } __packed; 57 58 struct gve_tx_mtd_desc { 59 uint8_t type_flags; /* type is lower 4 bits, subtype upper */ 60 uint8_t path_state; /* state is lower 4 bits, hash type upper */ 61 __be16 reserved0; 62 __be32 path_hash; 63 __be64 reserved1; 64 } __packed; 65 66 struct gve_tx_seg_desc { 67 uint8_t type_flags; /* type is lower 4 bits, flags upper */ 68 uint8_t l3_offset; /* TSO: 2 byte units to start of IPH */ 69 __be16 reserved; 70 __be16 mss; /* TSO MSS */ 71 __be16 seg_len; 72 __be64 seg_addr; 73 } __packed; 74 75 /* GVE Transmit Descriptor Types */ 76 #define GVE_TXD_STD (0x0 << 4) /* Std with Host Address */ 77 #define GVE_TXD_TSO (0x1 << 4) /* TSO with Host Address */ 78 #define GVE_TXD_SEG (0x2 << 4) /* Seg with Host Address */ 79 #define GVE_TXD_MTD (0x3 << 4) /* Metadata */ 80 81 /* GVE Transmit Descriptor Flags for Std Pkts */ 82 #define GVE_TXF_L4CSUM BIT(0) /* Need csum offload */ 83 #define GVE_TXF_TSTAMP BIT(2) /* Timestamp required */ 84 85 /* GVE Transmit Descriptor Flags for TSO Segs */ 86 #define GVE_TXSF_IPV6 BIT(1) /* IPv6 TSO */ 87 88 /* GVE Transmit Descriptor Options for MTD Segs */ 89 #define GVE_MTD_SUBTYPE_PATH 0 90 91 #define GVE_MTD_PATH_STATE_DEFAULT 0 92 #define GVE_MTD_PATH_STATE_TIMEOUT 1 93 #define GVE_MTD_PATH_STATE_CONGESTION 2 94 #define GVE_MTD_PATH_STATE_RETRANSMIT 3 95 96 #define GVE_MTD_PATH_HASH_NONE (0x0 << 4) 97 #define GVE_MTD_PATH_HASH_L4 (0x1 << 4) 98 99 /* 100 * GVE Receive Packet Descriptor 101 * 102 * The start of an ethernet packet comes 2 bytes into the rx buffer. 103 * gVNIC adds this padding so that both the DMA and the L3/4 protocol header 104 * access is aligned. 105 */ 106 #define GVE_RX_PAD 2 107 108 struct gve_rx_desc { 109 uint8_t padding[48]; 110 __be32 rss_hash; /* Receive-side scaling hash (Toeplitz for gVNIC) */ 111 __be16 mss; 112 __be16 reserved; /* Reserved to zero */ 113 uint8_t hdr_len; /* Header length (L2-L4) including padding */ 114 uint8_t hdr_off; /* 64-byte-scaled offset into RX_DATA entry */ 115 uint16_t csum; /* 1's-complement partial checksum of L3+ bytes */ 116 __be16 len; /* Length of the received packet */ 117 __be16 flags_seq; /* Flags [15:3] and sequence number [2:0] (1-7) */ 118 } __packed; 119 _Static_assert(sizeof(struct gve_rx_desc) == 64, "gve: bad desc struct length"); 120 121 /* 122 * If the device supports raw dma addressing then the addr in data slot is 123 * the dma address of the buffer. 124 * If the device only supports registered segments then the addr is a byte 125 * offset into the registered segment (an ordered list of pages) where the 126 * buffer is. 127 */ 128 union gve_rx_data_slot { 129 __be64 qpl_offset; 130 __be64 addr; 131 }; 132 133 /* GVE Recive Packet Descriptor Seq No */ 134 #define GVE_SEQNO(x) (be16toh(x) & 0x7) 135 136 /* GVE Recive Packet Descriptor Flags */ 137 #define GVE_RXFLG(x) htobe16(1 << (3 + (x))) 138 #define GVE_RXF_FRAG GVE_RXFLG(3) /* IP Fragment */ 139 #define GVE_RXF_IPV4 GVE_RXFLG(4) /* IPv4 */ 140 #define GVE_RXF_IPV6 GVE_RXFLG(5) /* IPv6 */ 141 #define GVE_RXF_TCP GVE_RXFLG(6) /* TCP Packet */ 142 #define GVE_RXF_UDP GVE_RXFLG(7) /* UDP Packet */ 143 #define GVE_RXF_ERR GVE_RXFLG(8) /* Packet Error Detected */ 144 #define GVE_RXF_PKT_CONT GVE_RXFLG(10) /* Multi Fragment RX packet */ 145 146 /* GVE IRQ */ 147 #define GVE_IRQ_ACK BIT(31) 148 #define GVE_IRQ_MASK BIT(30) 149 #define GVE_IRQ_EVENT BIT(29) 150 151 #endif /* _GVE_DESC_H_ */ 152