consts.h

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#ifndef SOFTWARE_INCLUDE_ENSO_CONSTS_H_
#define SOFTWARE_INCLUDE_ENSO_CONSTS_H_
 
#include <cstdint>
#include <string>
 
namespace enso {
 
// These determine the maximum number of notification buffers and enso pipes,
// these macros also exist in hardware and **must be kept in sync**. Update the
// variables with the same name on `hardware/src/constants.sv`,
// `software/kernel/linux/intel_fpga_pcie_setup.h`, and
// `scripts/hwtest/my_stats.tcl`.
#define MAX_NB_APPS 1024
#define MAX_NB_FLOWS 8192
 
constexpr uint32_t kMaxNbApps = MAX_NB_APPS;
constexpr uint32_t kMaxNbFlows = MAX_NB_FLOWS;
 
constexpr uint32_t kMaxTransferLen = 131072;
 
// Maximum number of tails to process at once.
constexpr uint32_t kBatchSize = 64;
 
#ifndef NOTIFICATION_BUF_SIZE
// This should be the max buffer supported by the hardware, we may override this
// value when compiling. It is defined in number of flits (64 bytes).
#define NOTIFICATION_BUF_SIZE 16384
#endif
constexpr uint32_t kNotificationBufSize = NOTIFICATION_BUF_SIZE;
 
#ifndef ENSO_PIPE_SIZE
// This should be the max buffer supported by the hardware, we may override this
// value when compiling. It is defined in number of flits (64 bytes).
#define ENSO_PIPE_SIZE 32768
#endif
constexpr uint32_t kEnsoPipeSize = ENSO_PIPE_SIZE;
 
constexpr uint32_t kMaxPendingTxRequests = kNotificationBufSize - 1;
 
// Using 2MB huge pages (size in bytes).
constexpr uint32_t kBufPageSize = 1UL << 21;
 
// Huge page paths.
static constexpr std::string_view kHugePageDefaultPrefix = "/mnt/huge/enso";
static constexpr std::string_view kHugePageRxPipePathPrefix = "_rx_pipe:";
static constexpr std::string_view kHugePagePathPrefix = "_tx_pipe:";
static constexpr std::string_view kHugePageNotifBufPathPrefix = "_notif_buf:";
static constexpr std::string_view kHugePageQueuePathPrefix = "_queue:";
 
// We need this to allow the same huge page to be mapped to adjacent memory
// regions.
// TODO(sadok): support other buffer sizes. It may be possible to support
// other buffer sizes by overlaying regular pages on top of the huge pages.
// We might use those only for requests that overlap to avoid adding too
// many entries to the TLB.
static_assert(ENSO_PIPE_SIZE * 64 == kBufPageSize, "Unsupported buffer size");
 
constexpr uint32_t kAlignedDscBufPairSize =
    ((kNotificationBufSize * 64 * 2 - 1) / kBufPageSize + 1) * kBufPageSize;
 
constexpr uint32_t kNsPerTimestampCycle = 5;
 
constexpr uint8_t kDefaultRttOffset = 18;
 
constexpr uint32_t kMaxHardwareFlitRate = 200e6;
 
constexpr uint32_t kMemorySpacePerQueue = 1 << 12;
 
constexpr uint32_t kCacheLineSize = 64;  // bytes.
 
// Software backend definitions.
 
// IPC queue names for software backend.
static constexpr std::string_view kIpcQueueToAppName = "enso_ipc_queue_to_app";
static constexpr std::string_view kIpcQueueFromAppName =
    "enso_ipc_queue_from_app";
 
enum class NotifType : uint8_t {
  kWrite = 0,
  kRead = 1,
  kTranslAddr = 2,  // Used to translate physical address to virtual address in
                    // the software backend address space.
  kAllocatePipe = 3,
  kAllocateNotifBuf = 4,
  kGetNbFallbackQueues = 5,
  kSetRrStatus = 6,
  kGetRrStatus = 7,
  kFreeNotifBuf = 8,
  kFreePipe = 9
};
 
struct MmioNotification {
  NotifType type;
  uint64_t address;
  uint64_t value;
};
 
struct FallbackNotification {
  NotifType type;
  uint64_t nb_fallback_queues;
  uint64_t result;
};
 
struct RoundRobinNotification {
  NotifType type;
  uint64_t round_robin;
  uint64_t result;
};
 
struct NotifBufNotification {
  NotifType type;
  uint64_t notif_buf_id;
  uint64_t result;
};
 
struct AllocatePipeNotification {
  NotifType type;
  uint64_t fallback;
  uint64_t pipe_id;
};
 
struct FreePipeNotification {
  NotifType type;
  uint64_t pipe_id;
  uint64_t result;
};
 
struct PipeNotification {
  NotifType type;
  uint64_t data[2];
};
 
}  // namespace enso
 
#endif  // SOFTWARE_INCLUDE_ENSO_CONSTS_H_