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 "../rdma_utils.h" 21 #include "standard-headers/drivers/infiniband/hw/vmw_pvrdma/pvrdma_ring.h" 22 #include "pvrdma_dev_ring.h" 23 24 int pvrdma_ring_init(PvrdmaRing *ring, const char *name, PCIDevice *dev, 25 struct pvrdma_ring *ring_state, uint32_t max_elems, 26 size_t elem_sz, dma_addr_t *tbl, uint32_t npages) 27 { 28 int i; 29 int rc = 0; 30 31 strncpy(ring->name, name, MAX_RING_NAME_SZ); 32 ring->name[MAX_RING_NAME_SZ - 1] = 0; 33 pr_dbg("Initializing %s ring\n", ring->name); 34 ring->dev = dev; 35 ring->ring_state = ring_state; 36 ring->max_elems = max_elems; 37 ring->elem_sz = elem_sz; 38 pr_dbg("ring->elem_sz=%zu\n", ring->elem_sz); 39 pr_dbg("npages=%d\n", npages); 40 /* TODO: Give a moment to think if we want to redo driver settings 41 atomic_set(&ring->ring_state->prod_tail, 0); 42 atomic_set(&ring->ring_state->cons_head, 0); 43 */ 44 ring->npages = npages; 45 ring->pages = g_malloc(npages * sizeof(void *)); 46 47 for (i = 0; i < npages; i++) { 48 if (!tbl[i]) { 49 pr_err("npages=%ld but tbl[%d] is NULL\n", (long)npages, i); 50 continue; 51 } 52 53 ring->pages[i] = rdma_pci_dma_map(dev, tbl[i], TARGET_PAGE_SIZE); 54 if (!ring->pages[i]) { 55 rc = -ENOMEM; 56 pr_dbg("Failed to map to page %d\n", i); 57 goto out_free; 58 } 59 memset(ring->pages[i], 0, TARGET_PAGE_SIZE); 60 } 61 62 goto out; 63 64 out_free: 65 while (i--) { 66 rdma_pci_dma_unmap(dev, ring->pages[i], TARGET_PAGE_SIZE); 67 } 68 g_free(ring->pages); 69 70 out: 71 return rc; 72 } 73 74 void *pvrdma_ring_next_elem_read(PvrdmaRing *ring) 75 { 76 int e; 77 unsigned int idx = 0, offset; 78 79 e = pvrdma_idx_ring_has_data(ring->ring_state, ring->max_elems, &idx); 80 if (e <= 0) { 81 pr_dbg("No more data in ring\n"); 82 return NULL; 83 } 84 85 offset = idx * ring->elem_sz; 86 return ring->pages[offset / TARGET_PAGE_SIZE] + (offset % TARGET_PAGE_SIZE); 87 } 88 89 void pvrdma_ring_read_inc(PvrdmaRing *ring) 90 { 91 pvrdma_idx_ring_inc(&ring->ring_state->cons_head, ring->max_elems); 92 /* 93 pr_dbg("%s: t=%d, h=%d, m=%ld\n", ring->name, 94 ring->ring_state->prod_tail, ring->ring_state->cons_head, 95 ring->max_elems); 96 */ 97 } 98 99 void *pvrdma_ring_next_elem_write(PvrdmaRing *ring) 100 { 101 int idx; 102 unsigned int offset, tail; 103 104 idx = pvrdma_idx_ring_has_space(ring->ring_state, ring->max_elems, &tail); 105 if (idx <= 0) { 106 pr_dbg("CQ is full\n"); 107 return NULL; 108 } 109 110 idx = pvrdma_idx(&ring->ring_state->prod_tail, ring->max_elems); 111 if (idx < 0 || tail != idx) { 112 pr_dbg("invalid idx\n"); 113 return NULL; 114 } 115 116 offset = idx * ring->elem_sz; 117 return ring->pages[offset / TARGET_PAGE_SIZE] + (offset % TARGET_PAGE_SIZE); 118 } 119 120 void pvrdma_ring_write_inc(PvrdmaRing *ring) 121 { 122 pvrdma_idx_ring_inc(&ring->ring_state->prod_tail, ring->max_elems); 123 /* 124 pr_dbg("%s: t=%d, h=%d, m=%ld\n", ring->name, 125 ring->ring_state->prod_tail, ring->ring_state->cons_head, 126 ring->max_elems); 127 */ 128 } 129 130 void pvrdma_ring_free(PvrdmaRing *ring) 131 { 132 if (!ring) { 133 return; 134 } 135 136 if (!ring->pages) { 137 return; 138 } 139 140 pr_dbg("ring->npages=%d\n", ring->npages); 141 while (ring->npages--) { 142 rdma_pci_dma_unmap(ring->dev, ring->pages[ring->npages], 143 TARGET_PAGE_SIZE); 144 } 145 146 g_free(ring->pages); 147 ring->pages = NULL; 148 } 149