1 /* SPDX-License-Identifier: GPL-2.0 */ 2 3 #include "kublk.h" 4 5 #ifndef IORING_NOP_INJECT_RESULT 6 #define IORING_NOP_INJECT_RESULT (1U << 0) 7 #endif 8 9 #ifndef IORING_NOP_FIXED_BUFFER 10 #define IORING_NOP_FIXED_BUFFER (1U << 3) 11 #endif 12 13 static int ublk_null_tgt_init(const struct dev_ctx *ctx, struct ublk_dev *dev) 14 { 15 const struct ublksrv_ctrl_dev_info *info = &dev->dev_info; 16 unsigned long dev_size = 250UL << 30; 17 18 dev->tgt.dev_size = dev_size; 19 dev->tgt.params = (struct ublk_params) { 20 .types = UBLK_PARAM_TYPE_BASIC | UBLK_PARAM_TYPE_DMA_ALIGN | 21 UBLK_PARAM_TYPE_SEGMENT, 22 .basic = { 23 .logical_bs_shift = 9, 24 .physical_bs_shift = 12, 25 .io_opt_shift = 12, 26 .io_min_shift = 9, 27 .max_sectors = info->max_io_buf_bytes >> 9, 28 .dev_sectors = dev_size >> 9, 29 }, 30 .dma = { 31 .alignment = 4095, 32 }, 33 .seg = { 34 .seg_boundary_mask = 4095, 35 .max_segment_size = 32 << 10, 36 .max_segments = 32, 37 }, 38 }; 39 ublk_set_integrity_params(ctx, &dev->tgt.params); 40 41 if (info->flags & UBLK_F_SUPPORT_ZERO_COPY) 42 dev->tgt.sq_depth = dev->tgt.cq_depth = 2 * info->queue_depth; 43 return 0; 44 } 45 46 static void __setup_nop_io(int tag, const struct ublksrv_io_desc *iod, 47 struct io_uring_sqe *sqe, int q_id) 48 { 49 unsigned ublk_op = ublksrv_get_op(iod); 50 51 io_uring_prep_nop(sqe); 52 sqe->buf_index = tag; 53 sqe->flags |= IOSQE_FIXED_FILE; 54 sqe->rw_flags = IORING_NOP_FIXED_BUFFER | IORING_NOP_INJECT_RESULT; 55 sqe->len = iod->nr_sectors << 9; /* injected result */ 56 sqe->user_data = build_user_data(tag, ublk_op, 0, q_id, 1); 57 } 58 59 static int null_queue_zc_io(struct ublk_thread *t, struct ublk_queue *q, 60 int tag) 61 { 62 const struct ublksrv_io_desc *iod = ublk_get_iod(q, tag); 63 struct io_uring_sqe *sqe[3]; 64 65 ublk_io_alloc_sqes(t, sqe, 3); 66 67 io_uring_prep_buf_register(sqe[0], q, tag, q->q_id, ublk_get_io(q, tag)->buf_index); 68 sqe[0]->user_data = build_user_data(tag, 69 ublk_cmd_op_nr(sqe[0]->cmd_op), 0, q->q_id, 1); 70 sqe[0]->flags |= IOSQE_CQE_SKIP_SUCCESS | IOSQE_IO_HARDLINK; 71 72 __setup_nop_io(tag, iod, sqe[1], q->q_id); 73 sqe[1]->flags |= IOSQE_IO_HARDLINK; 74 75 io_uring_prep_buf_unregister(sqe[2], q, tag, q->q_id, ublk_get_io(q, tag)->buf_index); 76 sqe[2]->user_data = build_user_data(tag, ublk_cmd_op_nr(sqe[2]->cmd_op), 0, q->q_id, 1); 77 78 // buf register is marked as IOSQE_CQE_SKIP_SUCCESS 79 return 2; 80 } 81 82 static int null_queue_auto_zc_io(struct ublk_thread *t, struct ublk_queue *q, 83 int tag) 84 { 85 const struct ublksrv_io_desc *iod = ublk_get_iod(q, tag); 86 struct io_uring_sqe *sqe[1]; 87 88 ublk_io_alloc_sqes(t, sqe, 1); 89 __setup_nop_io(tag, iod, sqe[0], q->q_id); 90 return 1; 91 } 92 93 static void ublk_null_io_done(struct ublk_thread *t, struct ublk_queue *q, 94 const struct io_uring_cqe *cqe) 95 { 96 unsigned tag = user_data_to_tag(cqe->user_data); 97 unsigned op = user_data_to_op(cqe->user_data); 98 struct ublk_io *io = ublk_get_io(q, tag); 99 100 if (cqe->res < 0 || op != ublk_cmd_op_nr(UBLK_U_IO_UNREGISTER_IO_BUF)) { 101 if (!io->result) 102 io->result = cqe->res; 103 if (cqe->res < 0) 104 ublk_err("%s: io failed op %x user_data %lx\n", 105 __func__, op, cqe->user_data); 106 } 107 108 /* buffer register op is IOSQE_CQE_SKIP_SUCCESS */ 109 if (op == ublk_cmd_op_nr(UBLK_U_IO_REGISTER_IO_BUF)) 110 io->tgt_ios += 1; 111 112 if (ublk_completed_tgt_io(t, q, tag)) 113 ublk_complete_io(t, q, tag, io->result); 114 } 115 116 static int ublk_null_queue_io(struct ublk_thread *t, struct ublk_queue *q, 117 int tag) 118 { 119 const struct ublksrv_io_desc *iod = ublk_get_iod(q, tag); 120 unsigned auto_zc = ublk_queue_use_auto_zc(q); 121 unsigned zc = ublk_queue_use_zc(q); 122 int queued; 123 124 if (auto_zc && !ublk_io_auto_zc_fallback(iod)) 125 queued = null_queue_auto_zc_io(t, q, tag); 126 else if (zc) 127 queued = null_queue_zc_io(t, q, tag); 128 else { 129 ublk_complete_io(t, q, tag, iod->nr_sectors << 9); 130 return 0; 131 } 132 ublk_queued_tgt_io(t, q, tag, queued); 133 return 0; 134 } 135 136 /* 137 * return invalid buffer index for triggering auto buffer register failure, 138 * then UBLK_IO_RES_NEED_REG_BUF handling is covered 139 */ 140 static unsigned short ublk_null_buf_index(const struct ublk_queue *q, int tag) 141 { 142 if (ublk_queue_auto_zc_fallback(q)) 143 return (unsigned short)-1; 144 return q->ios[tag].buf_index; 145 } 146 147 const struct ublk_tgt_ops null_tgt_ops = { 148 .name = "null", 149 .init_tgt = ublk_null_tgt_init, 150 .queue_io = ublk_null_queue_io, 151 .tgt_io_done = ublk_null_io_done, 152 .buf_index = ublk_null_buf_index, 153 }; 154