LXR qemu/hw/rdma/vmw/pvrdma_dev

   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 "qemu/cutils.h"
  18#include "hw/pci/pci.h"
  19#include "cpu.h"
  20#include "qemu/cutils.h"
  21
  22#include "trace.h"
  23
  24#include "../rdma_utils.h"
  25#include "standard-headers/drivers/infiniband/hw/vmw_pvrdma/pvrdma_ring.h"
  26#include "pvrdma_dev_ring.h"
  27
  28int pvrdma_ring_init(PvrdmaRing *ring, const char *name, PCIDevice *dev,
  29                     struct pvrdma_ring *ring_state, uint32_t max_elems,
  30                     size_t elem_sz, dma_addr_t *tbl, uint32_t npages)
  31{
  32    int i;
  33    int rc = 0;
  34
  35    pstrcpy(ring->name, MAX_RING_NAME_SZ, name);
  36    ring->dev = dev;
  37    ring->ring_state = ring_state;
  38    ring->max_elems = max_elems;
  39    ring->elem_sz = elem_sz;
  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            rdma_error_report("npages=%d but tbl[%d] is NULL", 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            rdma_error_report("Failed to map to page %d in ring %s", i, name);
  57            goto out_free;
  58        }
  59        memset(ring->pages[i], 0, TARGET_PAGE_SIZE);
  60    }
  61
  62    goto out;
  63
  64out_free:
  65    while (i--) {
  66        rdma_pci_dma_unmap(dev, ring->pages[i], TARGET_PAGE_SIZE);
  67    }
  68    g_free(ring->pages);
  69
  70out:
  71    return rc;
  72}
  73
  74void *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        trace_pvrdma_ring_next_elem_read_no_data(ring->name);
  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
  89void pvrdma_ring_read_inc(PvrdmaRing *ring)
  90{
  91    pvrdma_idx_ring_inc(&ring->ring_state->cons_head, ring->max_elems);
  92}
  93
  94void *pvrdma_ring_next_elem_write(PvrdmaRing *ring)
  95{
  96    int idx;
  97    unsigned int offset, tail;
  98
  99    idx = pvrdma_idx_ring_has_space(ring->ring_state, ring->max_elems, &tail);
 100    if (idx <= 0) {
 101        rdma_error_report("CQ is full");
 102        return NULL;
 103    }
 104
 105    idx = pvrdma_idx(&ring->ring_state->prod_tail, ring->max_elems);
 106    if (idx < 0 || tail != idx) {
 107        rdma_error_report("Invalid idx %d", idx);
 108        return NULL;
 109    }
 110
 111    offset = idx * ring->elem_sz;
 112    return ring->pages[offset / TARGET_PAGE_SIZE] + (offset % TARGET_PAGE_SIZE);
 113}
 114
 115void pvrdma_ring_write_inc(PvrdmaRing *ring)
 116{
 117    pvrdma_idx_ring_inc(&ring->ring_state->prod_tail, ring->max_elems);
 118}
 119
 120void pvrdma_ring_free(PvrdmaRing *ring)
 121{
 122    if (!ring) {
 123        return;
 124    }
 125
 126    if (!ring->pages) {
 127        return;
 128    }
 129
 130    while (ring->npages--) {
 131        rdma_pci_dma_unmap(ring->dev, ring->pages[ring->npages],
 132                           TARGET_PAGE_SIZE);
 133    }
 134
 135    g_free(ring->pages);
 136    ring->pages = NULL;
 137}
 138