C++ SharedMemBufferPtr::GetAlignment方法代码示例

void
CQ::Init(uint16_t qId, uint16_t entrySize, uint16_t numEntries,
    const SharedMemBufferPtr memBuffer, bool irqEnabled, uint16_t irqVec)
{
    Queue::Init(qId, entrySize, numEntries);
    mIrqEnabled = irqEnabled;
    mIrqVec = irqVec;


    LOG_NRM("Allocating discontiguous CQ memory in tnvme");
    if (numEntries < 2)
        LOG_WARN("Number elements breaches spec requirement");

    if (memBuffer == MemBuffer::NullMemBufferPtr) {
        LOG_DBG("Passing an uninitialized SharedMemBufferPtr");
        throw exception();
    } else if (GetIsAdmin()) {
        // There are no appropriate methods for an NVME device to report ASC/ACQ
        // creation errors, thus since ASC/ASQ may only be contiguous then don't
        // allow these problems to be injected, at best they will only succeed
        // to seg fault the app or crash the kernel.
        LOG_DBG("Illegal memory alignment will corrupt");
        throw exception();
    } else  if (memBuffer->GetBufSize() < GetQSize()) {
        LOG_DBG("Q buffer memory ambiguous to passed size params");
        LOG_DBG("Mem buffer size = %d, Q size = %d", memBuffer->GetBufSize(),
            GetQSize());
        throw exception();
    } else if (memBuffer->GetAlignment() != sysconf(_SC_PAGESIZE)) {
        // Nonconformance to page alignment will seg fault the app or crash
        // the kernel. This state is not testable since no errors can be
        // reported by hdw, thus disallow this attempt.
        LOG_DBG("Q content memory shall be page aligned");
        throw exception();
    }

    // Zero out the content memory so the P-bit correlates to a newly alloc'd Q.
    // Also assuming life time ownership of this object if it wasn't created
    // by the RsrcMngr.
    mDiscontigBuf = memBuffer;
    mDiscontigBuf->Zero();

    // We are creating a discontiguous IOCQ
    struct nvme_prep_cq q;
    q.cq_id = GetQId();
    q.elements = GetNumEntries();
    q.contig = false;
    CreateIOCQ(q);

    LOG_NRM(
        "Created CQ: (id, entrySize, numEntry, IRQEnable) = (%d, %d, %d, %s)",
        GetQId(), GetEntrySize(), GetNumEntries(), GetIrqEnabled() ? "T" : "F");
}

void
SQ::Init(uint16_t qId, uint16_t entrySize, uint32_t numEntries,
    const SharedMemBufferPtr memBuffer, uint16_t cqId)
{
    uint64_t work;


    mCqId = cqId;
    Queue::Init(qId, entrySize, numEntries);
    LOG_NRM("Create SQ: (id,cqid,entrySize,numEntries) = (%d,%d,%d,%d)",
        GetQId(), GetCqId(), GetEntrySize(), GetNumEntries());

    LOG_NRM("Allocating discontiguous SQ memory in tnvme");
    if (numEntries < 2) {
        throw FrmwkEx(HERE, "Number elements breaches spec requirement");
    } else if (gRegisters->Read(CTLSPC_CAP, work) == false) {
        throw FrmwkEx(HERE, "Unable to determine MQES");
    }

    // Detect if doing something that looks suspicious/incorrect/illegal
    work &= CAP_MQES;
    work += 1;      // convert to 1-based
    if (work < (uint64_t)numEntries) {
        LOG_WARN("Creating Q with %d entries, but DUT only allows %d",
            numEntries, (uint32_t)work);
    }


    if (memBuffer == MemBuffer::NullMemBufferPtr) {
        throw FrmwkEx(HERE, "Passing an uninitialized SharedMemBufferPtr");
    } else if (GetIsAdmin()) {
        // There are no appropriate methods for an NVME device to report ASC/ACQ
        // creation errors, thus since ASC/ASQ may only be contiguous then don't
        // allow these problems to be injected, at best they will only succeed
        // to seg fault the app or crash the kernel.
        throw FrmwkEx(HERE, "Illegal memory alignment will corrupt");
    } else  if (memBuffer->GetBufSize() < GetQSize()) {
        LOG_ERR("Q buffer memory ambiguous to passed size params");
        throw FrmwkEx(HERE, "Mem buffer size = %d, Q size = %d",
            memBuffer->GetBufSize(), GetQSize());
    } else if (memBuffer->GetAlignment() != sysconf(_SC_PAGESIZE)) {
        // Nonconformance to page alignment will seg fault the app or crash
        // the kernel. This state is not testable since no errors can be
        // reported by hdw, thus disallow this attempt.
        throw FrmwkEx(HERE, "Q content memory shall be page aligned");
    }

    // Zero out the content memory so the P-bit correlates to a newly alloc'd Q.
    // Also assuming life time ownership of this object if it wasn't created
    // by the RsrcMngr.
    mDiscontigBuf = memBuffer;
    mDiscontigBuf->Zero();

    // We are creating a discontiguous IOSQ
    struct nvme_prep_sq q;
    q.sq_id = GetQId();
    q.cq_id = GetCqId();
    q.elements = GetNumEntries();
    q.contig = false;
    CreateIOSQ(q);
}