hw/rdma/vmw/pvrdma_dev_ring.c

   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 }