banan-os/kernel/kernel/Storage/NVMe/Queue.cpp

114 lines
3.0 KiB
C++

#include <kernel/Lock/LockGuard.h>
#include <kernel/Storage/NVMe/Queue.h>
#include <kernel/Thread.h>
#include <kernel/Timer/Timer.h>
namespace Kernel
{
static constexpr uint64_t s_nvme_command_timeout_ms = 1000;
static constexpr uint64_t s_nvme_command_poll_timeout_ms = 20;
NVMeQueue::NVMeQueue(BAN::UniqPtr<Kernel::DMARegion>&& cq, BAN::UniqPtr<Kernel::DMARegion>&& sq, volatile NVMe::DoorbellRegisters& db, uint32_t qdepth, uint8_t irq)
: m_completion_queue(BAN::move(cq))
, m_submission_queue(BAN::move(sq))
, m_doorbell(db)
, m_qdepth(qdepth)
{
for (uint32_t i = qdepth; i < m_mask_bits; i++)
m_used_mask |= (size_t)1 << i;
set_irq(irq);
enable_interrupt();
}
void NVMeQueue::handle_irq()
{
auto* cq_ptr = reinterpret_cast<NVMe::CompletionQueueEntry*>(m_completion_queue->vaddr());
while ((cq_ptr[m_cq_head].sts & 1) == m_cq_valid_phase)
{
uint16_t sts = cq_ptr[m_cq_head].sts >> 1;
uint16_t cid = cq_ptr[m_cq_head].cid;
size_t cid_mask = (size_t)1 << cid;
ASSERT(cid < m_mask_bits);
ASSERT((m_done_mask & cid_mask) == 0);
m_status_codes[cid] = sts;
m_done_mask |= cid_mask;
m_cq_head = (m_cq_head + 1) % m_qdepth;
if (m_cq_head == 0)
m_cq_valid_phase ^= 1;
}
m_doorbell.cq_head = m_cq_head;
m_thread_blocker.unblock();
}
uint16_t NVMeQueue::submit_command(NVMe::SubmissionQueueEntry& sqe)
{
uint16_t cid = reserve_cid();
size_t cid_mask = (size_t)1 << cid;
{
SpinLockGuard _(m_lock);
m_done_mask &= ~cid_mask;
m_status_codes[cid] = 0;
sqe.cid = cid;
auto* sqe_ptr = reinterpret_cast<NVMe::SubmissionQueueEntry*>(m_submission_queue->vaddr());
memcpy(&sqe_ptr[m_sq_tail], &sqe, sizeof(NVMe::SubmissionQueueEntry));
m_sq_tail = (m_sq_tail + 1) % m_qdepth;
m_doorbell.sq_tail = m_sq_tail;
}
const uint64_t start_time_ms = SystemTimer::get().ms_since_boot();
while (!(m_done_mask & cid_mask) && SystemTimer::get().ms_since_boot() < start_time_ms + s_nvme_command_poll_timeout_ms)
continue;
// FIXME: Here is a possible race condition if done mask is set before
// scheduler has put the current thread blocking.
// EINTR should also be handled here.
while (!(m_done_mask & cid_mask) && SystemTimer::get().ms_since_boot() < start_time_ms + s_nvme_command_timeout_ms)
m_thread_blocker.block_with_wake_time_ms(start_time_ms + s_nvme_command_timeout_ms);
if (m_done_mask & cid_mask)
{
uint16_t status = m_status_codes[cid];
m_used_mask &= ~cid_mask;
return status;
}
m_used_mask &= ~cid_mask;
return 0xFFFF;
}
uint16_t NVMeQueue::reserve_cid()
{
auto state = m_lock.lock();
while (~m_used_mask == 0)
{
m_lock.unlock(state);
m_thread_blocker.block_with_timeout_ms(s_nvme_command_timeout_ms);
state = m_lock.lock();
}
uint16_t cid = 0;
for (; cid < m_mask_bits; cid++)
if ((m_used_mask & ((size_t)1 << cid)) == 0)
break;
ASSERT(cid < m_mask_bits);
ASSERT(cid < m_qdepth);
m_used_mask |= (size_t)1 << cid;
m_lock.unlock(state);
return cid;
}
}