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Kernel: Add polling support to NVMe

Add polling support to NVMe so that it does not use interrupt to
complete a IO but instead actively polls for completion. This probably
is not very efficient in terms of CPU usage but it does not use
interrupts to complete a IO which is beneficial at the moment as there
is no MSI(X) support and it can reduce the latency of an IO in a very
fast NVMe device.

The NVMeQueue class has been made the base class for NVMeInterruptQueue
and NVMePollQueue. The factory function `NVMeQueue::try_create` will
return the appropriate queue to the controller based on the polling
boot parameter.

The polling mode can be enabled by adding an extra boot parameter:
`nvme_poll`.
This commit is contained in:
Pankaj Raghav 2022-01-27 16:44:58 +05:30 committed by Andreas Kling
parent aa832ee251
commit d234e6b801
13 changed files with 211 additions and 83 deletions

View file

@ -26,8 +26,8 @@ namespace Kernel {
class NVMeController : public PCI::Device
, public StorageController {
public:
static ErrorOr<NonnullRefPtr<NVMeController>> try_initialize(PCI::DeviceIdentifier const&);
ErrorOr<void> initialize();
static ErrorOr<NonnullRefPtr<NVMeController>> try_initialize(PCI::DeviceIdentifier const&, bool is_queue_polled);
ErrorOr<void> initialize(bool is_queue_polled);
explicit NVMeController(PCI::DeviceIdentifier const&);
RefPtr<StorageDevice> device(u32 index) const override;
size_t devices_count() const override;
@ -58,8 +58,8 @@ public:
private:
ErrorOr<void> identify_and_init_namespaces();
Tuple<u64, u8> get_ns_features(IdentifyNamespace& identify_data_struct);
ErrorOr<void> create_admin_queue(u8 irq);
ErrorOr<void> create_io_queue(u8 irq, u8 qid);
ErrorOr<void> create_admin_queue(Optional<u8> irq);
ErrorOr<void> create_io_queue(u8 qid, Optional<u8> irq);
void calculate_doorbell_stride()
{
m_dbl_stride = (m_controller_regs->cap >> CAP_DBL_SHIFT) & CAP_DBL_MASK;