1 /* 2 * QEMU paravirtual RDMA - Device rings 3 * 4 * Copyright (C) 2018 Oracle 5 * Copyright (C) 2018 Red Hat Inc 6 * 7 * Authors: 8 * Yuval Shaia <yuval.shaia@oracle.com> 9 * Marcel Apfelbaum <marcel@redhat.com> 10 * 11 * This work is licensed under the terms of the GNU GPL, version 2 or later. 12 * See the COPYING file in the top-level directory. 13 * 14 */ 15 16 #include "qemu/osdep.h" 17 #include "hw/pci/pci.h" 18 #include "cpu.h" 19 20 #include "trace.h" 21 22 #include "../rdma_utils.h" 23 #include "standard-headers/drivers/infiniband/hw/vmw_pvrdma/pvrdma_ring.h" 24 #include "pvrdma_dev_ring.h" 25 26 int pvrdma_ring_init(PvrdmaRing *ring, const char *name, PCIDevice *dev, 27 struct pvrdma_ring *ring_state, uint32_t max_elems, 28 size_t elem_sz, dma_addr_t *tbl, uint32_t npages) 29 { 30 int i; 31 int rc = 0; 32 33 strncpy(ring->name, name, MAX_RING_NAME_SZ); 34 ring->name[MAX_RING_NAME_SZ - 1] = 0; 35 ring->dev = dev; 36 ring->ring_state = ring_state; 37 ring->max_elems = max_elems; 38 ring->elem_sz = elem_sz; 39 /* TODO: Give a moment to think if we want to redo driver settings 40 atomic_set(&ring->ring_state->prod_tail, 0); 41 atomic_set(&ring->ring_state->cons_head, 0); 42 */ 43 ring->npages = npages; 44 ring->pages = g_malloc(npages * sizeof(void *)); 45 46 for (i = 0; i < npages; i++) { 47 if (!tbl[i]) { 48 rdma_error_report("npages=%d but tbl[%d] is NULL", npages, i); 49 continue; 50 } 51 52 ring->pages[i] = rdma_pci_dma_map(dev, tbl[i], TARGET_PAGE_SIZE); 53 if (!ring->pages[i]) { 54 rc = -ENOMEM; 55 rdma_error_report("Failed to map to page %d in ring %s", i, name); 56 goto out_free; 57 } 58 memset(ring->pages[i], 0, TARGET_PAGE_SIZE); 59 } 60 61 goto out; 62 63 out_free: 64 while (i--) { 65 rdma_pci_dma_unmap(dev, ring->pages[i], TARGET_PAGE_SIZE); 66 } 67 g_free(ring->pages); 68 69 out: 70 return rc; 71 } 72 73 void *pvrdma_ring_next_elem_read(PvrdmaRing *ring) 74 { 75 int e; 76 unsigned int idx = 0, offset; 77 78 e = pvrdma_idx_ring_has_data(ring->ring_state, ring->max_elems, &idx); 79 if (e <= 0) { 80 trace_pvrdma_ring_next_elem_read_no_data(ring->name); 81 return NULL; 82 } 83 84 offset = idx * ring->elem_sz; 85 return ring->pages[offset / TARGET_PAGE_SIZE] + (offset % TARGET_PAGE_SIZE); 86 } 87 88 void pvrdma_ring_read_inc(PvrdmaRing *ring) 89 { 90 pvrdma_idx_ring_inc(&ring->ring_state->cons_head, ring->max_elems); 91 } 92 93 void *pvrdma_ring_next_elem_write(PvrdmaRing *ring) 94 { 95 int idx; 96 unsigned int offset, tail; 97 98 idx = pvrdma_idx_ring_has_space(ring->ring_state, ring->max_elems, &tail); 99 if (idx <= 0) { 100 rdma_error_report("CQ is full"); 101 return NULL; 102 } 103 104 idx = pvrdma_idx(&ring->ring_state->prod_tail, ring->max_elems); 105 if (idx < 0 || tail != idx) { 106 rdma_error_report("Invalid idx %d", idx); 107 return NULL; 108 } 109 110 offset = idx * ring->elem_sz; 111 return ring->pages[offset / TARGET_PAGE_SIZE] + (offset % TARGET_PAGE_SIZE); 112 } 113 114 void pvrdma_ring_write_inc(PvrdmaRing *ring) 115 { 116 pvrdma_idx_ring_inc(&ring->ring_state->prod_tail, ring->max_elems); 117 } 118 119 void pvrdma_ring_free(PvrdmaRing *ring) 120 { 121 if (!ring) { 122 return; 123 } 124 125 if (!ring->pages) { 126 return; 127 } 128 129 while (ring->npages--) { 130 rdma_pci_dma_unmap(ring->dev, ring->pages[ring->npages], 131 TARGET_PAGE_SIZE); 132 } 133 134 g_free(ring->pages); 135 ring->pages = NULL; 136 } 137