Cleanup AHCI Ident a bit and reduce logging

Additionally add the first lock class since we are becoming more
concurrent.

lib/mammoth/CMakeLists.txt

@@ -1,6 +1,7 @@
 add_library(mammoth_lib STATIC
   src/channel.cpp
   src/debug.cpp
+  src/memory_region.cpp
   src/process.cpp
   src/thread.cpp
   )

lib/mammoth/include/mammoth/memory_region.h

@@ -0,0 +1,29 @@
+#pragma once
+
+#include <stdint.h>
+
+class MappedMemoryRegion {
+ public:
+  // FIXME: Introduce optional type to contain error or.
+  static MappedMemoryRegion DirectPhysical(uint64_t phys_addr, uint64_t size);
+  static MappedMemoryRegion ContiguousPhysical(uint64_t size);
+  static MappedMemoryRegion Default(uint64_t size);
+
+  MappedMemoryRegion() {}
+  // TODO: Disallow copy before doing any cleanup here.
+  ~MappedMemoryRegion() {}
+
+  uint64_t paddr() { return paddr_; }
+  uint64_t vaddr() { return vaddr_; }
+
+  operator bool() { return vmmo_cap_ != 0; }
+
+ private:
+  MappedMemoryRegion(uint64_t vmmo_cap, uint64_t paddr, uint64_t vaddr,
+                     uint64_t size)
+      : vmmo_cap_(vmmo_cap), paddr_(paddr), vaddr_(vaddr), size_(size) {}
+  uint64_t vmmo_cap_ = 0;
+  uint64_t paddr_ = 0;
+  uint64_t vaddr_ = 0;
+  uint64_t size_ = 0;
+};

lib/mammoth/src/memory_region.cpp

@@ -0,0 +1,36 @@
+#include "mammoth/memory_region.h"
+
+#include <zcall.h>
+
+#include "mammoth/debug.h"
+
+MappedMemoryRegion MappedMemoryRegion::DirectPhysical(uint64_t paddr,
+                                                      uint64_t size) {
+  uint64_t vmmo_cap;
+  check(ZMemoryObjectCreatePhysical(paddr, size, &vmmo_cap));
+
+  uint64_t vaddr;
+  check(ZAddressSpaceMap(Z_INIT_VMAS_SELF, 0, vmmo_cap, &vaddr));
+
+  return MappedMemoryRegion(vmmo_cap, paddr, vaddr, size);
+}
+
+MappedMemoryRegion MappedMemoryRegion::ContiguousPhysical(uint64_t size) {
+  uint64_t vmmo_cap, paddr;
+  check(ZMemoryObjectCreateContiguous(size, &vmmo_cap, &paddr));
+
+  uint64_t vaddr;
+  check(ZAddressSpaceMap(Z_INIT_VMAS_SELF, 0, vmmo_cap, &vaddr));
+
+  return MappedMemoryRegion(vmmo_cap, paddr, vaddr, size);
+}
+
+MappedMemoryRegion MappedMemoryRegion::Default(uint64_t size) {
+  uint64_t vmmo_cap;
+  check(ZMemoryObjectCreate(size, &vmmo_cap));
+
+  uint64_t vaddr;
+  check(ZAddressSpaceMap(Z_INIT_VMAS_SELF, 0, vmmo_cap, &vaddr));
+
+  return MappedMemoryRegion(vmmo_cap, 0, vaddr, size);
+}

sys/denali/ahci/ahci.h

@@ -35,7 +35,7 @@ struct PciMsiCap {
   uint8_t reserved;
   uint64_t message_address;
   uint16_t message_data;
-};
+} __attribute__((packed));
 
 struct AhciHba {
   uint32_t capabilities;
@@ -90,7 +90,7 @@ struct PhysicalRegionDescriptor {
   // 21:0 is byte count
   // 31 is Interrupt on Completion
   uint32_t byte_count;
-};
+} __attribute__((packed));
 
 struct CommandTable {
   uint8_t command_fis[64];
@@ -110,9 +110,73 @@ typedef enum {
   FIS_TYPE_DEV_BITS = 0xA1,   // Set device bits FIS - device to host
 } FIS_TYPE;
 
-struct DmaFis {};
+struct DmaFis {
+  // DWORD 0
+  uint8_t fis_type;  // FIS_TYPE_DMA_SETUP
+
+  uint8_t pmport : 4;  // Port multiplier
+  uint8_t rsv0 : 1;    // Reserved
+  uint8_t d : 1;       // Data transfer direction, 1 - device to host
+  uint8_t i : 1;       // Interrupt bit
+  uint8_t a : 1;       // Auto-activate. Specifies if DMA Activate FIS is needed
+
+  uint8_t rsved[2];  // Reserved
+
+  // DWORD 1&2
+
+  uint64_t DMAbufferID;  // DMA Buffer Identifier. Used to Identify DMA buffer
+                         // in host memory. SATA Spec says host specific and not
+                         // in Spec. Trying AHCI spec might work.
+
+  // DWORD 3
+  uint32_t rsvd;  // More reserved
+
+  // DWORD 4
+  uint32_t DMAbufOffset;  // Byte offset into buffer. First 2 bits must be 0
+
+  // DWORD 5
+  uint32_t TransferCount;  // Number of bytes to transfer. Bit 0 must be 0
+
+  // DWORD 6
+  uint32_t resvd;  // Reserved
+} __attribute__((packed));
+
+struct PioSetupFis {
+  // DWORD 0
+  uint8_t fis_type;  // FIS_TYPE_PIO_SETUP
+
+  uint8_t pmport : 4;  // Port multiplier
+  uint8_t rsv0 : 1;    // Reserved
+  uint8_t d : 1;       // Data transfer direction, 1 - device to host
+  uint8_t i : 1;       // Interrupt bit
+  uint8_t rsv1 : 1;
+
+  uint8_t status;  // Status register
+  uint8_t error;   // Error register
+
+  // DWORD 1
+  uint8_t lba0;    // LBA low register, 7:0
+  uint8_t lba1;    // LBA mid register, 15:8
+  uint8_t lba2;    // LBA high register, 23:16
+  uint8_t device;  // Device register
+
+  // DWORD 2
+  uint8_t lba3;  // LBA register, 31:24
+  uint8_t lba4;  // LBA register, 39:32
+  uint8_t lba5;  // LBA register, 47:40
+  uint8_t rsv2;  // Reserved
+
+  // DWORD 3
+  uint8_t countl;    // Count register, 7:0
+  uint8_t counth;    // Count register, 15:8
+  uint8_t rsv3;      // Reserved
+  uint8_t e_status;  // New value of status register
+
+  // DWORD 4
+  uint16_t tc;      // Transfer count
+  uint8_t rsv4[2];  // Reserved
+} __attribute__((packed));
 
-struct PioSetupFis {};
 struct HostToDeviceRegisterFis {
   uint8_t fis_type;  // FIS_TYPE_REG_H2D
   uint8_t pmp_and_c;
@@ -138,9 +202,36 @@ struct HostToDeviceRegisterFis {
 
   // DWORD 4
   uint32_t reserved;  // Reserved
-};
+} __attribute__((packed));
-struct DeviceToHostRegisterFis {};
+struct DeviceToHostRegisterFis {
-struct SetDeviceBitsFis {};
+  // DWORD 0
+  uint8_t fis_type;  // FIS_TYPE_REG_D2H
+
+  uint8_t pmport_and_i;
+
+  uint8_t status;  // Status register
+  uint8_t error;   // Error register
+
+  // DWORD 1
+  uint8_t lba0;    // LBA low register, 7:0
+  uint8_t lba1;    // LBA mid register, 15:8
+  uint8_t lba2;    // LBA high register, 23:16
+  uint8_t device;  // Device register
+
+  // DWORD 2
+  uint8_t lba3;  // LBA register, 31:24
+  uint8_t lba4;  // LBA register, 39:32
+  uint8_t lba5;  // LBA register, 47:40
+  uint8_t reserved1;
+
+  // DWORD 3
+  uint16_t count;
+  uint16_t reserved2;
+
+  uint32_t reserved3;
+} __attribute__((packed));
+struct SetDeviceBitsFis {
+} __attribute__((packed));
 
 struct ReceivedFis {
   DmaFis dma_fis;

sys/denali/ahci/ahci_device.cpp

@@ -4,6 +4,12 @@
 #include <string.h>
 #include <zcall.h>
 
+namespace {
+
+void HandleIdent(AhciDevice* dev) { dev->HandleIdentify(); }
+
+}  // namespace
+
 AhciDevice::AhciDevice(AhciPort* port) : port_struct_(port) {
   if ((port_struct_->sata_status & 0x103) != 0x103) {
     return;
@@ -15,26 +21,30 @@ AhciDevice::AhciDevice(AhciPort* port) : port_struct_(port) {
     crash("Non adjacent cl & fis", Z_ERR_UNIMPLEMENTED);
   }
 
-  check(ZMemoryObjectCreatePhysical(cl_page, 0x1000, &vmmo_cap_));
+  command_structures_ = MappedMemoryRegion::DirectPhysical(cl_page, 0x1000);
-
-  uint64_t vaddr;
-  check(ZAddressSpaceMap(Z_INIT_VMAS_SELF, 0, vmmo_cap_, &vaddr));
 
   uint64_t cl_off = port_struct_->command_list_base & 0xFFF;
-  command_list_ = reinterpret_cast<CommandList*>(vaddr + cl_off);
+  command_list_ =
+      reinterpret_cast<CommandList*>(command_structures_.vaddr() + cl_off);
 
   uint64_t fis_off = port_struct_->fis_base & 0xFFF;
-  received_fis_ = reinterpret_cast<ReceivedFis*>(vaddr + fis_off);
+  received_fis_ =
+      reinterpret_cast<ReceivedFis*>(command_structures_.vaddr() + fis_off);
 
   // FIXME: Hacky
   uint64_t ct_off =
       command_list_->command_headers[0].command_table_base_addr & 0xFFF;
-  command_table_ = reinterpret_cast<CommandTable*>(vaddr + ct_off);
+  command_table_ =
+      reinterpret_cast<CommandTable*>(command_structures_.vaddr() + ct_off);
 
   port_struct_->interrupt_enable = 0xFFFFFFFF;
+
+  if (port_struct_->signature == 0x101) {
+    SendIdentify();
+  }
 }
 
-z_err_t AhciDevice::SendIdentify(uint16_t** result) {
+z_err_t AhciDevice::SendIdentify() {
   HostToDeviceRegisterFis fis{
       .fis_type = FIS_TYPE_REG_H2D,
       .pmp_and_c = 0x80,
@@ -63,22 +73,24 @@ z_err_t AhciDevice::SendIdentify(uint16_t** result) {
 
   memcpy(command_table_->command_fis, &fis, sizeof(fis));
 
-  port_struct_->command_issue |= 1;
+  commands_[0].region = MappedMemoryRegion::ContiguousPhysical(512);
+  commands_[0].callback = HandleIdent;
 
-  uint64_t vmmo_cap, paddr;
+  command_table_->prds[0].region_address = commands_[0].region.paddr();
-  RET_ERR(ZMemoryObjectCreateContiguous(512, &vmmo_cap, &paddr));
-
-  command_table_->prds[0].region_address = paddr;
   command_table_->prds[0].byte_count = 512;
 
-  uint64_t vaddr;
+  port_struct_->command_issue |= 1;
-  RET_ERR(ZAddressSpaceMap(Z_INIT_VMAS_SELF, 0, vmmo_cap, &vaddr));
+  commands_issued_ |= 1;
-
-  *result = reinterpret_cast<uint16_t*>(vaddr);
 
   return Z_OK;
 }
 
+void AhciDevice::HandleIdentify() {
+  dbgln("Handling Idenify");
+  uint16_t* ident = reinterpret_cast<uint16_t*>(commands_[0].region.vaddr());
+  dbgln("Ident: %x", ident[0]);
+}
+
 void AhciDevice::DumpInfo() {
   dbgln("Comlist: %lx", port_struct_->command_list_base);
   dbgln("FIS: %lx", port_struct_->fis_base);
@@ -87,7 +99,6 @@ void AhciDevice::DumpInfo() {
   dbgln("SATA status: %x", port_struct_->sata_status);
   dbgln("Int status: %x", port_struct_->interrupt_status);
   dbgln("Int enable: %x", port_struct_->interrupt_enable);
-  dbgln("Int enable: %x", port_struct_->interrupt_enable);
 
   // Just dump one command info for now.
   for (uint64_t i = 0; i < 1; i++) {
@@ -104,5 +115,36 @@ void AhciDevice::HandleIrq() {
   // FIXME: Probably only clear the interrupts we know how to handle.
   port_struct_->interrupt_status = int_status;
 
-  dbgln("int receieved: %x", int_status);
+  uint32_t commands_finished = commands_issued_ & ~port_struct_->command_issue;
+
+  for (uint64_t i = 0; i < 32; i++) {
+    if (commands_finished & (1 << i)) {
+      commands_[i].callback(this);
+      commands_issued_ &= ~(1 << i);
+    }
+  }
+
+  // TODO: Do something with this information.
+  if (int_status & 0x1) {
+    // Device to host.
+    DeviceToHostRegisterFis& fis = received_fis_->device_to_host_register_fis;
+    if (fis.fis_type != FIS_TYPE_REG_D2H) {
+      dbgln("BAD FIS TYPE (exp,act): %x, %x", FIS_TYPE_REG_D2H, fis.fis_type);
+      return;
+    }
+    if (fis.error) {
+      dbgln("D2H err: %x", fis.error);
+    }
+  }
+  if (int_status & 0x2) {
+    // PIO.
+    PioSetupFis& fis = received_fis_->pio_set_fis;
+    if (fis.fis_type != FIS_TYPE_PIO_SETUP) {
+      dbgln("BAD FIS TYPE (exp,act): %x, %x", FIS_TYPE_PIO_SETUP, fis.fis_type);
+      return;
+    }
+    if (fis.error) {
+      dbgln("PIO err: %x", fis.error);
+    }
+  }
 }

sys/denali/ahci/ahci_device.h

@@ -1,5 +1,6 @@
 #pragma once
 
+#include <mammoth/memory_region.h>
 #include <zerrors.h>
 
 #include "ahci/ahci.h"
@@ -12,18 +13,26 @@ class AhciDevice {
 
   void DumpInfo();
 
-  bool IsInit() { return port_struct_ != nullptr && vmmo_cap_ != 0; }
+  bool IsInit() { return port_struct_ != nullptr && command_structures_; }
 
-  // Result will point to a 512 byte (256 word array).
+  z_err_t SendIdentify();
-  z_err_t SendIdentify(uint16_t** result);
+  void HandleIdentify();
 
   void HandleIrq();
 
  private:
   AhciPort* port_struct_ = nullptr;
-  uint64_t vmmo_cap_ = 0;
+  MappedMemoryRegion command_structures_;
 
   CommandList* command_list_ = nullptr;
   ReceivedFis* received_fis_ = nullptr;
   CommandTable* command_table_ = nullptr;
+
+  struct Command {
+    typedef void (*Callback)(AhciDevice*);
+    MappedMemoryRegion region;
+    Callback callback;
+  };
+  Command commands_[32];
+  uint32_t commands_issued_ = 0;
 };

sys/denali/ahci/ahci_driver.cpp

@@ -13,7 +13,6 @@ const uint64_t kGhc_InteruptEnable = 0x2;
 
 void interrupt_thread(void* void_driver) {
   AhciDriver* driver = static_cast<AhciDriver*>(void_driver);
-  dbgln("this %lx", driver);
 
   driver->InterruptLoop();
 
@@ -24,17 +23,13 @@ void interrupt_thread(void* void_driver) {
 
 z_err_t AhciDriver::Init() {
   RET_ERR(LoadPciDeviceHeader());
-  RET_ERR(LoadCapabilities());
+  // RET_ERR(LoadCapabilities());
-  dbgln("ABAR: %x", pci_device_header_->abar);
-  dbgln("Interrupt line: %x", pci_device_header_->interrupt_line);
-  dbgln("Interrupt pin: %x", pci_device_header_->interrupt_pin);
   RET_ERR(RegisterIrq());
   RET_ERR(LoadHbaRegisters());
-  dbgln("Version: %x", ahci_hba_->version);
   ahci_hba_->global_host_control |= kGhc_InteruptEnable;
   RET_ERR(LoadDevices());
-  DumpCapabilities();
+  // DumpCapabilities();
-  DumpPorts();
+  // DumpPorts();
   return Z_OK;
 }
 
@@ -42,8 +37,6 @@ void AhciDriver::DumpCapabilities() {
   dbgln("AHCI Capabilities:");
   uint32_t caps = ahci_hba_->capabilities;
 
-  dbgln("Num Ports: %u", (caps & 0x1F) + 1);
-  dbgln("Num Command Slots: %u", ((caps & 0x1F00) >> 8) + 1);
   if (caps & 0x20) {
     dbgln("External SATA");
   }
@@ -132,25 +125,21 @@ void AhciDriver::DumpPorts() {
 }
 
 void AhciDriver::InterruptLoop() {
-  dbgln("this %lx", this);
   while (true) {
     uint64_t type, bytes, caps;
     check(ZPortRecv(irq_port_cap_, 0, 0, 0, 0, &type, &bytes, &caps));
-    for (uint64_t i = 0; i < 6; i++) {
+    for (uint64_t i = 0; i < 32; i++) {
-      if (devices_[i].IsInit()) {
+      if (devices_[i].IsInit() && (ahci_hba_->interrupt_status & (1 << i))) {
         devices_[i].HandleIrq();
+        ahci_hba_->interrupt_status &= ~(1 << i);
       }
     }
   }
 }
 
 z_err_t AhciDriver::LoadPciDeviceHeader() {
-  uint64_t vmmo_cap;
+  pci_region_ = MappedMemoryRegion::DirectPhysical(kSataPciPhys, kPciSize);
-  RET_ERR(ZMemoryObjectCreatePhysical(kSataPciPhys, kPciSize, &vmmo_cap));
+  pci_device_header_ = reinterpret_cast<PciDeviceHeader*>(pci_region_.vaddr());
-
-  uint64_t vaddr;
-  RET_ERR(ZAddressSpaceMap(Z_INIT_VMAS_SELF, 0, vmmo_cap, &vaddr));
-  pci_device_header_ = reinterpret_cast<PciDeviceHeader*>(vaddr);
   return Z_OK;
 }
 
@@ -189,37 +178,28 @@ z_err_t AhciDriver::RegisterIrq() {
   }
   uint64_t irq_num = Z_IRQ_PCI_BASE + pci_device_header_->interrupt_pin - 1;
   RET_ERR(ZIrqRegister(irq_num, &irq_port_cap_));
-  dbgln("this %lx", this);
   irq_thread_ = Thread(interrupt_thread, this);
   return Z_OK;
 }
 
 z_err_t AhciDriver::LoadHbaRegisters() {
-  uint64_t vmmo_cap;
+  ahci_region_ =
-  RET_ERR(
+      MappedMemoryRegion::DirectPhysical(pci_device_header_->abar, 0x1100);
-      ZMemoryObjectCreatePhysical(pci_device_header_->abar, 0x1100, &vmmo_cap));
+  ahci_hba_ = reinterpret_cast<AhciHba*>(ahci_region_.vaddr());
+  num_ports_ = (ahci_hba_->capabilities & 0x1F) + 1;
+  num_commands_ = ((ahci_hba_->capabilities & 0x1F00) >> 8) + 1;
 
-  uint64_t vaddr;
-  RET_ERR(ZAddressSpaceMap(Z_INIT_VMAS_SELF, 0, vmmo_cap, &vaddr));
-  ahci_hba_ = reinterpret_cast<AhciHba*>(vaddr);
   return Z_OK;
 }
 
 z_err_t AhciDriver::LoadDevices() {
-  // FIXME: Don't set this up so we hardcode 6 devices.
+  for (uint8_t i = 0; i < 32; i++) {
-  for (uint8_t i = 0; i < 6; i++) {
     if (!(ahci_hba_->port_implemented & (1 << i))) {
       continue;
     }
     uint64_t port_addr =
         reinterpret_cast<uint64_t>(ahci_hba_) + 0x100 + (0x80 * i);
     devices_[i] = AhciDevice(reinterpret_cast<AhciPort*>(port_addr));
-    if (!devices_[i].IsInit()) {
-      continue;
-    }
-    dbgln("Identify %u", i);
-    uint16_t* identify;
-    devices_[i].SendIdentify(&identify);
   }
   return Z_OK;
 }

sys/denali/ahci/ahci_driver.h

@@ -16,14 +16,20 @@ class AhciDriver {
   void DumpPorts();
 
  private:
+  MappedMemoryRegion pci_region_;
   PciDeviceHeader* pci_device_header_ = nullptr;
+  MappedMemoryRegion ahci_region_;
   AhciHba* ahci_hba_ = nullptr;
 
-  AhciDevice devices_[6];
+  // TODO: Allocate these dynamically.
+  AhciDevice devices_[32];
 
   Thread irq_thread_;
   uint64_t irq_port_cap_ = 0;
 
+  uint64_t num_ports_;
+  uint64_t num_commands_;
+
   z_err_t LoadPciDeviceHeader();
   z_err_t LoadCapabilities();
   z_err_t RegisterIrq();

zion/CMakeLists.txt

@@ -10,6 +10,7 @@ add_executable(zion
   interrupt/interrupt.cpp
   interrupt/interrupt_enter.s
   interrupt/timer.cpp
+  lib/mutex.cpp
   loader/init_loader.cpp
   memory/kernel_heap.cpp
   memory/kernel_stack_manager.cpp

zion/boot/acpi.cpp

@@ -136,7 +136,6 @@ void ParseMcfg(SdtHeader* rsdt) {
 void ParseMadt(SdtHeader* rsdt) {
 #if K_ACPI_DEBUG
   dbgsz(rsdt->signature, 4);
-#endif
   uint64_t max_addr = reinterpret_cast<uint64_t>(rsdt) + rsdt->length;
   MadtHeader* header = reinterpret_cast<MadtHeader*>(rsdt);
 
@@ -180,6 +179,7 @@ void ParseMadt(SdtHeader* rsdt) {
     entry = reinterpret_cast<MadtEntry*>(reinterpret_cast<uint64_t>(entry) +
                                          entry->length);
   }
+#endif
 }
 
 void ParseSdt(SdtHeader* rsdt) {

zion/debug/debug.cpp

@@ -76,8 +76,8 @@ void MemToStr(uint64_t u, char* str) {
 
 void AddProcPrefix() {
   if (gScheduler != nullptr) {
-    auto& t = gScheduler->CurrentThread();
+    auto t = gScheduler->CurrentThread();
-    dbg("[%u.%u] ", t.pid(), t.tid());
+    dbg("[%u.%u] ", t->pid(), t->tid());
   }
 }
 

zion/interrupt/apic.cpp

@@ -7,7 +7,7 @@
 #include "common/port.h"
 #include "debug/debug.h"
 
-#define APIC_DEBUG 1
+#define APIC_DEBUG 0
 
 namespace {
 

zion/lib/mutex.cpp

@@ -0,0 +1,11 @@
+#include "lib/mutex.h"
+
+#include "debug/debug.h"
+#include "scheduler/scheduler.h"
+
+void Mutex::Lock() {
+  while (__atomic_fetch_or(&lock_, 0x1, __ATOMIC_SEQ_CST) == 0x1) {
+    dbgln("Lock sleep: %s", name_);
+    gScheduler->Preempt();
+  }
+}

zion/lib/mutex.h

@@ -0,0 +1,29 @@
+#pragma once
+
+#include <stdint.h>
+
+class Mutex {
+ public:
+  Mutex(const char* name) : name_(name) {}
+
+  void Lock();
+  void Unlock() { lock_ = false; }
+
+ private:
+  const char* name_;
+
+  uint8_t lock_ = 0;
+};
+
+class MutexHolder {
+ public:
+  MutexHolder(Mutex& mutex) : mutex_(mutex) { mutex_.Lock(); }
+
+  ~MutexHolder() { mutex_.Unlock(); }
+
+  MutexHolder(MutexHolder&) = delete;
+  MutexHolder(MutexHolder&&) = delete;
+
+ private:
+  Mutex& mutex_;
+};

zion/memory/kernel_heap.cpp

@@ -24,7 +24,8 @@ KernelHeap::KernelHeap(uint64_t lower_bound, uint64_t upper_bound)
 
 void* KernelHeap::Allocate(uint64_t size) {
   if (next_addr_ + size >= upper_bound_) {
-    panic("Kernel Heap Overrun");
+    panic("Kernel Heap Overrun (next, size, max): %m, %x, %m", next_addr_, size,
+          upper_bound_);
   }
 #if K_HEAP_DEBUG
   RecordSize(size);

zion/memory/physical_memory.cpp

@@ -61,6 +61,9 @@ class PhysicalMemoryManager {
       front_ = front_->next;
       delete temp;
     }
+#if K_PHYS_DEBUG
+    dbgln("Single %m", page);
+#endif
     return page;
   }
   uint64_t AllocateContinuous(uint64_t num_pages) {
@@ -89,6 +92,9 @@ class PhysicalMemoryManager {
       front_ = front_->next;
       delete temp;
     }
+#if K_PHYS_DEBUG
+    dbgln("Continuous %m:%u", page, num_pages);
+#endif
     return page;
   }
   void FreePage(uint64_t page) { AddMemoryRegion(page, 0x1000); }

zion/memory/user_stack_manager.cpp

@@ -21,3 +21,14 @@ void UserStackManager::FreeUserStack(uint64_t stack_ptr) {
   freed_stacks_++;
   dbgln("%u freed user stacks", freed_stacks_);
 }
+
+bool UserStackManager::IsValidStack(uint64_t vaddr) {
+  if (vaddr < next_stack_ || vaddr > (kStackMax - 0x1000)) {
+    return false;
+  }
+  // Checks if the address is in the first page of the stack.
+  if (vaddr & 0xFF000) {
+    return true;
+  }
+  return false;
+}

zion/memory/user_stack_manager.h

@@ -20,6 +20,9 @@ class UserStackManager {
   uint64_t NewUserStack();
   void FreeUserStack(uint64_t stack_ptr);
 
+  // Used to check if we should page in this address.
+  bool IsValidStack(uint64_t vaddr);
+
  private:
   const uint64_t kStackMax = 0x00008000'00000000;
   const uint64_t kStackMin = 0x00007FF0'00000000;

zion/object/address_space.cpp

@@ -55,6 +55,11 @@ bool AddressSpace::HandlePageFault(uint64_t vaddr) {
 #if K_VMAS_DEBUG
   dbgln("[VMAS] Page Fault!");
 #endif
+  if (user_stacks_.IsValidStack(vaddr)) {
+    MapPage(cr3_, vaddr, phys_mem::AllocatePage());
+    return true;
+  }
+
   MemoryMapping* mapping = GetMemoryMappingForAddr(vaddr);
   if (mapping == nullptr) {
     return false;

zion/object/port.cpp

@@ -1,5 +1,7 @@
 #include "object/port.h"
 
+#include "scheduler/scheduler.h"
+
 Port::Port() {}
 
 z_err_t Port::Write(const ZMessage& msg) {
@@ -21,16 +23,26 @@ z_err_t Port::Write(const ZMessage& msg) {
   for (uint64_t i = 0; i < msg.num_bytes; i++) {
     message.bytes[i] = msg.bytes[i];
   }
+
+  MutexHolder lock(mutex_);
   pending_messages_.PushBack(message);
+  if (blocked_threads_.size() > 0) {
+    gScheduler->Enqueue(blocked_threads_.PopFront());
+  }
   return Z_OK;
 }
 
 z_err_t Port::Read(ZMessage& msg) {
-  if (pending_messages_.size() < 1) {
+  mutex_.Lock();
-    dbgln("Implement blocking");
+  while (pending_messages_.size() < 1) {
-    return Z_ERR_UNIMPLEMENTED;
+    blocked_threads_.PushBack(gScheduler->CurrentThread());
+    mutex_.Unlock();
+    gScheduler->Yield();
+    mutex_.Lock();
   }
+  mutex_.Unlock();
 
+  MutexHolder lock(mutex_);
   Message next_msg = pending_messages_.PeekFront();
   if (next_msg.num_bytes > msg.num_bytes) {
     return Z_ERR_BUFF_SIZE;

zion/object/port.h

@@ -1,7 +1,9 @@
 #pragma once
 
 #include "lib/linked_list.h"
+#include "lib/mutex.h"
 #include "object/kernel_object.h"
+#include "object/thread.h"
 #include "usr/zcall_internal.h"
 
 class Port : public KernelObject {
@@ -19,4 +21,8 @@ class Port : public KernelObject {
   };
 
   LinkedList<Message> pending_messages_;
+
+  LinkedList<RefPtr<Thread>> blocked_threads_;
+
+  Mutex mutex_{"Port"};
 };

zion/object/process.cpp

@@ -34,12 +34,14 @@ Process::Process()
     : id_(gNextId++), vmas_(MakeRefCounted<AddressSpace>()), state_(RUNNING) {}
 
 RefPtr<Thread> Process::CreateThread() {
+  MutexHolder lock(mutex_);
   RefPtr<Thread> thread = MakeRefCounted<Thread>(*this, next_thread_id_++);
   threads_.PushBack(thread);
   return thread;
 }
 
 RefPtr<Thread> Process::GetThread(uint64_t tid) {
+  MutexHolder lock(mutex_);
   auto iter = threads_.begin();
   while (iter != threads_.end()) {
     if (iter->tid() == tid) {
@@ -52,6 +54,7 @@ RefPtr<Thread> Process::GetThread(uint64_t tid) {
 }
 
 void Process::CheckState() {
+  MutexHolder lock(mutex_);
   auto iter = threads_.begin();
   while (iter != threads_.end()) {
     if (iter->GetState() != Thread::FINISHED) {
@@ -63,6 +66,7 @@ void Process::CheckState() {
 }
 
 RefPtr<Capability> Process::ReleaseCapability(uint64_t cid) {
+  MutexHolder lock(mutex_);
   auto iter = caps_.begin();
   while (iter != caps_.end()) {
     if (*iter && iter->id() == cid) {
@@ -78,6 +82,7 @@ RefPtr<Capability> Process::ReleaseCapability(uint64_t cid) {
 }
 
 RefPtr<Capability> Process::GetCapability(uint64_t cid) {
+  MutexHolder lock(mutex_);
   auto iter = caps_.begin();
   while (iter != caps_.end()) {
     if (*iter && iter->id() == cid) {
@@ -91,11 +96,13 @@ RefPtr<Capability> Process::GetCapability(uint64_t cid) {
 }
 
 uint64_t Process::AddCapability(const RefPtr<Capability>& cap) {
+  MutexHolder lock(mutex_);
   cap->set_id(next_cap_id_++);
   caps_.PushBack(cap);
   return cap->id();
 }
 uint64_t Process::AddCapability(const RefPtr<Thread>& thread) {
+  MutexHolder lock(mutex_);
   uint64_t cap_id = next_cap_id_++;
   caps_.PushBack(
       MakeRefCounted<Capability>(thread, Capability::THREAD, cap_id, ZC_WRITE));
@@ -103,24 +110,28 @@ uint64_t Process::AddCapability(const RefPtr<Thread>& thread) {
 }
 
 uint64_t Process::AddCapability(const RefPtr<Process>& p) {
+  MutexHolder lock(mutex_);
   uint64_t cap_id = next_cap_id_++;
   caps_.PushBack(MakeRefCounted<Capability>(p, Capability::PROCESS, cap_id,
                                             ZC_WRITE | ZC_PROC_SPAWN_THREAD));
   return cap_id;
 }
 uint64_t Process::AddCapability(const RefPtr<AddressSpace>& vmas) {
+  MutexHolder lock(mutex_);
   uint64_t cap_id = next_cap_id_++;
   caps_.PushBack(MakeRefCounted<Capability>(vmas, Capability::ADDRESS_SPACE,
                                             cap_id, ZC_WRITE));
   return cap_id;
 }
 uint64_t Process::AddCapability(const RefPtr<MemoryObject>& vmmo) {
+  MutexHolder lock(mutex_);
   uint64_t cap_id = next_cap_id_++;
   caps_.PushBack(MakeRefCounted<Capability>(vmmo, Capability::MEMORY_OBJECT,
                                             cap_id, ZC_WRITE));
   return cap_id;
 }
 uint64_t Process::AddCapability(const RefPtr<Channel>& chan) {
+  MutexHolder lock(mutex_);
   uint64_t cap_id = next_cap_id_++;
   caps_.PushBack(MakeRefCounted<Capability>(chan, Capability::CHANNEL, cap_id,
                                             ZC_WRITE | ZC_READ));
@@ -128,6 +139,7 @@ uint64_t Process::AddCapability(const RefPtr<Channel>& chan) {
 }
 
 uint64_t Process::AddCapability(const RefPtr<Port>& port) {
+  MutexHolder lock(mutex_);
   uint64_t cap_id = next_cap_id_++;
   caps_.PushBack(MakeRefCounted<Capability>(port, Capability::PORT, cap_id,
                                             ZC_WRITE | ZC_READ));
@@ -135,6 +147,7 @@ uint64_t Process::AddCapability(const RefPtr<Port>& port) {
 }
 
 void Process::AddCapability(uint64_t cap_id, const RefPtr<MemoryObject>& vmmo) {
+  MutexHolder lock(mutex_);
   caps_.PushBack(MakeRefCounted<Capability>(vmmo, Capability::MEMORY_OBJECT,
                                             cap_id, ZC_WRITE));
 }

zion/object/process.h

@@ -4,6 +4,7 @@
 
 #include "capability/capability.h"
 #include "lib/linked_list.h"
+#include "lib/mutex.h"
 #include "lib/ref_ptr.h"
 #include "object/address_space.h"
 #include "object/channel.h"
@@ -51,6 +52,9 @@ class Process : public KernelObject {
   friend class MakeRefCountedFriend<Process>;
   Process();
   Process(uint64_t id) : id_(id), vmas_(AddressSpace::ForRoot()) {}
+
+  Mutex mutex_{"Process"};
+
   uint64_t id_;
   RefPtr<AddressSpace> vmas_;
   State state_;

zion/object/thread.cpp

@@ -15,7 +15,7 @@ extern "C" void jump_user_space(uint64_t rip, uint64_t rsp, uint64_t arg1,
 
 extern "C" void thread_init() {
   asm("sti");
-  gScheduler->CurrentThread().Init();
+  gScheduler->CurrentThread()->Init();
   panic("Reached end of thread.");
 }
 

zion/scheduler/scheduler.h

@@ -13,7 +13,7 @@ class Scheduler {
   void Enable() { enabled_ = true; }
 
   Process& CurrentProcess() { return current_thread_->process(); }
-  Thread& CurrentThread() { return *current_thread_; }
+  RefPtr<Thread> CurrentThread() { return current_thread_; }
 
   void Enqueue(const RefPtr<Thread>& thread) {
     runnable_threads_.PushBack(thread);

zion/syscall/syscall.cpp

@@ -24,7 +24,7 @@ extern "C" void syscall_enter();
 
 // Used by syscall_enter.s
 extern "C" uint64_t GetKernelRsp() {
-  return gScheduler->CurrentThread().Rsp0Start();
+  return gScheduler->CurrentThread()->Rsp0Start();
 }
 
 void InitSyscall() {
@@ -138,7 +138,7 @@ z_err_t MemoryObjectCreatePhysical(ZMemoryObjectCreatePhysicalReq* req,
   auto& curr_proc = gScheduler->CurrentProcess();
   uint64_t paddr = req->paddr;
   if (paddr == 0) {
-    paddr = phys_mem::AllocateContinuous((req->size - 1 / 0x1000) + 1);
+    paddr = phys_mem::AllocateContinuous(((req->size - 1) / 0x1000) + 1);
   }
   auto vmmo_ref = MakeRefCounted<FixedMemoryObject>(paddr, req->size);
   resp->vmmo_cap =
@@ -187,7 +187,6 @@ z_err_t ChannelRecv(ZChannelRecvReq* req) {
 
 z_err_t PortRecv(ZPortRecvReq* req) {
   auto& proc = gScheduler->CurrentProcess();
-  dbgln("Port cap %u", req->port_cap);
   auto port_cap = proc.GetCapability(req->port_cap);
   RET_ERR(ValidateCap(port_cap, Capability::PORT, ZC_READ));
 
@@ -199,23 +198,21 @@ z_err_t IrqRegister(ZIrqRegisterReq* req, ZIrqRegisterResp* resp) {
   auto& proc = gScheduler->CurrentProcess();
   if (req->irq_num != Z_IRQ_PCI_BASE) {
     // FIXME: Don't hardcode this nonsense.
-    dbgln("Irq %x", req->irq_num);
     return Z_ERR_UNIMPLEMENTED;
   }
   RefPtr<Port> port = MakeRefCounted<Port>();
   resp->port_cap = proc.AddCapability(port);
-  dbgln("Port cap %u", resp->port_cap);
   RegisterPciPort(port);
   return Z_OK;
 }
 
 extern "C" z_err_t SyscallHandler(uint64_t call_id, void* req, void* resp) {
-  Thread& thread = gScheduler->CurrentThread();
+  RefPtr<Thread> thread = gScheduler->CurrentThread();
   switch (call_id) {
     case Z_PROCESS_EXIT:
       // FIXME: kill process here.
       dbgln("Exit code: %u", req);
-      thread.Exit();
+      thread->Exit();
       panic("Returned from thread exit");
       break;
     case Z_PROCESS_SPAWN:
@@ -227,7 +224,7 @@ extern "C" z_err_t SyscallHandler(uint64_t call_id, void* req, void* resp) {
     case Z_THREAD_START:
       return ThreadStart(reinterpret_cast<ZThreadStartReq*>(req));
     case Z_THREAD_EXIT:
-      thread.Exit();
+      thread->Exit();
       panic("Returned from thread exit");
       break;