pci_msi.cpp

#include <hw/pci_device.hpp>
#include <hw/pci.hpp>
#include <hw/msi.hpp>

// Message Signalled Interrupts registers
#define PCI_MSI_FLAGS_ENABLE  0x0001  /* MSI feature enabled */
#define PCI_MSI_FLAGS_QMASK   0x000e  /* Maximum queue size available */
#define PCI_MSI_FLAGS_QSIZE   0x0070  /* Message queue size configured */
#define PCI_MSI_FLAGS_64BIT   0x0080  /* 64-bit addresses allowed */
#define PCI_MSI_FLAGS_MASKBIT 0x0100  /* Per-vector masking capable */

#define PCI_MSI_FLAGS              2  /* Message Control */
#define PCI_MSI_RFU                3  /* Rest of capability flags */
#define PCI_MSI_ADDRESS_LO         4  /* Lower 32 bits */
#define PCI_MSI_ADDRESS_HI         8  /* Upper 32 bits (if PCI_MSI_FLAGS_64BIT set) */
#define PCI_MSI_DATA_32            8  /* 16 bits of data for 32-bit devices */
#define PCI_MSI_MASK_32           12  /* Mask bits register for 32-bit devices */
#define PCI_MSI_PENDING_32        16  /* Pending intrs for 32-bit devices */
#define PCI_MSI_DATA_64           12  /* 16 bits of data for 64-bit devices */
#define PCI_MSI_MASK_64           16  /* Mask bits register for 64-bit devices */
#define PCI_MSI_PENDING_64        20  /* Pending intrs for 64-bit devices */

namespace hw
{
  int PCI_Device::msi_cap()
  {
    return caps[static_cast<size_t>(PCI::cap_id::MSI)];
  }

  int PCI_Device::msix_cap()
  {
    return caps[static_cast<size_t>(PCI::cap_id::MSIX)];
  }

  void PCI_Device::init_msix()
  {
    assert(this->msix == nullptr);
    // disable intx
    auto cmd = read16(static_cast<uint8_t>(PCI::config_reg::CMD));
    write16(static_cast<uint8_t>(PCI::config_reg::CMD), cmd | (1 << 10));
    // enable MSI-X
    this->msix = new msix_t(*this, msix_cap());
    // deallocate if it failed
    if (this->msix->vectors() == 0) {
      delete this->msix;
    }
  }
  int PCI_Device::setup_msix_vector(uint8_t cpu, uint8_t irq)
  {
    return msix->setup_vector(cpu, irq);
  }
  void PCI_Device::rebalance_msix_vector(uint16_t idx, uint8_t cpu, uint8_t irq)
  {
    msix->redirect_vector(idx, cpu, irq);
  }

  void PCI_Device::deactivate_msix()
  {
    for (size_t ent = 0; ent < msix->vectors(); ent++) {
        msix->mask_entry(ent);
        msix->zero_entry(ent);
    }
  }

  uint8_t PCI_Device::get_msix_vectors()
  {
    if (this->msix == nullptr) return 0;
    return msix->vectors();
  }
}