DMA: Properly handle bus errors and DICR transitions

This commit is contained in:
Stenzek 2024-03-17 20:45:12 +10:00
parent fa6850902a
commit 2003c9452b
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@ -42,7 +42,8 @@ enum class SyncMode : u32
};
static constexpr PhysicalMemoryAddress BASE_ADDRESS_MASK = UINT32_C(0x00FFFFFF);
// static constexpr PhysicalMemoryAddress ADDRESS_MASK = UINT32_C(0x001FFFFC);
static constexpr PhysicalMemoryAddress TRANSFER_ADDRESS_MASK = UINT32_C(0x00FFFFFC);
static constexpr PhysicalMemoryAddress LINKED_LIST_TERMINATOR = UINT32_C(0x00FFFFFF);
struct ChannelState
{
@ -119,7 +120,7 @@ union DICR
{
u32 bits;
BitField<u32, bool, 15, 1> force_irq;
BitField<u32, bool, 15, 1> bus_error;
BitField<u32, bool, 16, 1> MDECin_irq_enable;
BitField<u32, bool, 17, 1> MDECout_irq_enable;
BitField<u32, bool, 18, 1> GPU_irq_enable;
@ -137,27 +138,33 @@ union DICR
BitField<u32, bool, 30, 1> OTC_irq_flag;
BitField<u32, bool, 31, 1> master_flag;
ALWAYS_INLINE bool IsIRQEnabled(Channel channel) const
ALWAYS_INLINE bool GetIRQEnabled(Channel channel) const
{
return ConvertToBoolUnchecked((bits >> (static_cast<u8>(channel) + 16)) & u32(1));
return ConvertToBoolUnchecked((bits >> (static_cast<u8>(channel) + 16)) & 1u);
}
ALWAYS_INLINE bool GetIRQFlag(Channel channel) const
{
return ConvertToBoolUnchecked((bits >> (static_cast<u8>(channel) + 24)) & u32(1));
return ConvertToBoolUnchecked((bits >> (static_cast<u8>(channel) + 24)) & 1u);
}
ALWAYS_INLINE void SetIRQFlag(Channel channel) { bits |= (u32(1) << (static_cast<u8>(channel) + 24)); }
ALWAYS_INLINE void ClearIRQFlag(Channel channel) { bits &= ~(u32(1) << (static_cast<u8>(channel) + 24)); }
ALWAYS_INLINE void SetIRQFlag(Channel channel) { bits |= (1u << (static_cast<u8>(channel) + 24)); }
ALWAYS_INLINE bool ShouldSetIRQFlag(Channel channel)
{
// bus errors trigger IRQ unconditionally, completion requires the master flag to be enabled
return ConvertToBoolUnchecked(((bits >> (static_cast<u8>(channel) + 16)) & ((bits >> 23) & 1u)));
}
ALWAYS_INLINE void UpdateMasterFlag()
{
master_flag = master_enable && ((((bits >> 16) & u32(0b1111111)) & ((bits >> 24) & u32(0b1111111))) != 0);
master_flag =
(((bits & (1u << 15)) != 0u) || // bus error, or
(((bits & (1u << 23)) != 0u) != 0u && (bits & (0b1111111u << 24)) != 0u)); // master enable + irq on any channel
}
};
} // namespace
static u32 GetAddressMask();
static void ClearState();
// is everything enabled for a channel to operate?
@ -175,6 +182,10 @@ static void UnhaltTransfer(void*, TickCount ticks, TickCount ticks_late);
template<Channel channel>
static bool TransferChannel();
static bool IsLinkedListTerminator(PhysicalMemoryAddress address);
static bool CheckForBusError(Channel channel, ChannelState& cs, PhysicalMemoryAddress address, u32 size);
static void CompleteTransfer(Channel channel, ChannelState& cs);
// from device -> memory
template<Channel channel>
static TickCount TransferDeviceToMemory(u32 address, u32 increment, u32 word_count);
@ -183,6 +194,8 @@ static TickCount TransferDeviceToMemory(u32 address, u32 increment, u32 word_cou
template<Channel channel>
static TickCount TransferMemoryToDevice(u32 address, u32 increment, u32 word_count);
// configuration
static TickCount s_max_slice_ticks = 1000;
static TickCount s_halt_ticks = 100;
@ -219,17 +232,11 @@ struct fmt::formatter<DMA::Channel> : fmt::formatter<fmt::string_view>
}
};
u32 DMA::GetAddressMask()
{
return Bus::g_ram_mask & 0xFFFFFFFCu;
}
void DMA::Initialize()
{
s_max_slice_ticks = g_settings.dma_max_slice_ticks;
s_halt_ticks = g_settings.dma_halt_ticks;
s_transfer_buffer.resize(32);
s_unhalt_event =
TimingEvents::CreateTimingEvent("DMA Transfer Unhalt", 1, s_max_slice_ticks, &DMA::UnhaltTransfer, nullptr, false);
Reset();
@ -300,17 +307,20 @@ u32 DMA::ReadRegister(u32 offset)
{
case 0x00:
{
Log_TracePrintf("DMA%u base address -> 0x%08X", channel_index, s_state[channel_index].base_address);
Log_TraceFmt("DMA[{}] base address -> 0x{:08X}", static_cast<Channel>(channel_index),
s_state[channel_index].base_address);
return s_state[channel_index].base_address;
}
case 0x04:
{
Log_TracePrintf("DMA%u block control -> 0x%08X", channel_index, s_state[channel_index].block_control.bits);
Log_TraceFmt("DMA[{}] block control -> 0x{:08X}", static_cast<Channel>(channel_index),
s_state[channel_index].block_control.bits);
return s_state[channel_index].block_control.bits;
}
case 0x08:
{
Log_TracePrintf("DMA%u channel control -> 0x%08X", channel_index, s_state[channel_index].channel_control.bits);
Log_TraceFmt("DMA[{}] channel control -> 0x{:08X}", static_cast<Channel>(channel_index),
s_state[channel_index].channel_control.bits);
return s_state[channel_index].channel_control.bits;
}
default:
@ -321,17 +331,17 @@ u32 DMA::ReadRegister(u32 offset)
{
if (offset == 0x70)
{
Log_TracePrintf("DPCR -> 0x%08X", s_DPCR.bits);
Log_TraceFmt("DPCR -> 0x{:08X}", s_DPCR.bits);
return s_DPCR.bits;
}
else if (offset == 0x74)
{
Log_TracePrintf("DPCR -> 0x%08X", s_DPCR.bits);
Log_TraceFmt("DICR -> 0x{:08X}", s_DICR.bits);
return s_DICR.bits;
}
}
Log_ErrorPrintf("Unhandled register read: %02X", offset);
Log_ErrorFmt("Unhandled register read: {:02X}", offset);
return UINT32_C(0xFFFFFFFF);
}
@ -367,7 +377,7 @@ void DMA::WriteRegister(u32 offset, u32 value)
state.channel_control.bits = (state.channel_control.bits & ~ChannelState::ChannelControl::WRITE_MASK) |
(value & ChannelState::ChannelControl::WRITE_MASK);
Log_TracePrintf("DMA channel {} channel control <- 0x{:08X}", static_cast<Channel>(channel_index),
Log_TraceFmt("DMA channel {} channel control <- 0x{:08X}", static_cast<Channel>(channel_index),
state.channel_control.bits);
// start/trigger bit must be enabled for OTC
@ -416,7 +426,7 @@ void DMA::WriteRegister(u32 offset, u32 value)
{
case 0x70:
{
Log_TracePrintf("DPCR <- 0x%08X", value);
Log_TraceFmt("DPCR <- 0x{:08X}", value);
s_DPCR.bits = value;
for (u32 i = 0; i < NUM_CHANNELS; i++)
@ -433,7 +443,7 @@ void DMA::WriteRegister(u32 offset, u32 value)
case 0x74:
{
Log_TracePrintf("DCIR <- 0x%08X", value);
Log_TraceFmt("DICR <- 0x{:08X}", value);
s_DICR.bits = (s_DICR.bits & ~DICR_WRITE_MASK) | (value & DICR_WRITE_MASK);
s_DICR.bits = s_DICR.bits & ~(value & DICR_RESET_MASK);
UpdateIRQ();
@ -445,7 +455,7 @@ void DMA::WriteRegister(u32 offset, u32 value)
}
}
Log_ErrorPrintf("Unhandled register write: %02X <- %08X", offset, value);
Log_ErrorFmt("Unhandled register write: {:02X} <- {:08X}", offset, value);
}
void DMA::SetRequest(Channel channel, bool request)
@ -491,20 +501,58 @@ bool DMA::IsTransferHalted()
void DMA::UpdateIRQ()
{
[[maybe_unused]] const auto old_dicr = s_DICR;
s_DICR.UpdateMasterFlag();
if (s_DICR.master_flag)
if (!old_dicr.master_flag && s_DICR.master_flag)
Log_TracePrintf("Firing DMA master interrupt");
InterruptController::SetLineState(InterruptController::IRQ::DMA, s_DICR.master_flag);
}
ALWAYS_INLINE_RELEASE bool DMA::IsLinkedListTerminator(PhysicalMemoryAddress address)
{
return ((address & LINKED_LIST_TERMINATOR) == LINKED_LIST_TERMINATOR);
}
ALWAYS_INLINE_RELEASE bool DMA::CheckForBusError(Channel channel, ChannelState& cs, PhysicalMemoryAddress address,
u32 size)
{
// Relying on a transfer partially happening at the end of RAM, then hitting a bus error would be pretty silly.
if ((address + size) > Bus::RAM_8MB_SIZE) [[unlikely]]
{
Log_DebugFmt("DMA bus error on channel {} at address 0x{:08X} size {}", channel, address, size);
cs.channel_control.enable_busy = false;
s_DICR.bus_error = true;
s_DICR.SetIRQFlag(channel);
UpdateIRQ();
return true;
}
return false;
}
ALWAYS_INLINE_RELEASE void DMA::CompleteTransfer(Channel channel, ChannelState& cs)
{
// start/busy bit is cleared on end of transfer
Log_DebugFmt("DMA transfer for channel {} complete", channel);
cs.channel_control.enable_busy = false;
if (s_DICR.ShouldSetIRQFlag(channel))
{
Log_DebugFmt("Setting DMA interrupt for channel {}", channel);
s_DICR.SetIRQFlag(channel);
UpdateIRQ();
}
}
// Plenty of games seem to suffer from this issue where they have a linked list DMA going while polling the
// controller. Using a too-large slice size will result in the serial timing being off, and the game thinking
// the controller is disconnected. So we don't hurt performance too much for the general case, we reduce this
// to equal CPU and DMA time when the controller is transferring, but otherwise leave it at the higher size.
enum : u32
enum : TickCount
{
SLICE_SIZE_WHEN_TRANSMITTING_PAD = 100,
HALT_TICKS_WHEN_TRANSMITTING_PAD = 100
HALT_TICKS_WHEN_TRANSMITTING_PAD = 100,
LINKED_LIST_HEADER_READ_TICKS = 10,
LINKED_LIST_BLOCK_SETUP_TICKS = 5,
};
TickCount DMA::GetTransferSliceTicks()
@ -529,7 +577,6 @@ template<DMA::Channel channel>
bool DMA::TransferChannel()
{
ChannelState& cs = s_state[static_cast<u32>(channel)];
const u32 mask = GetAddressMask();
const bool copy_to_device = cs.channel_control.copy_to_device;
@ -543,18 +590,23 @@ bool DMA::TransferChannel()
case SyncMode::Manual:
{
const u32 word_count = cs.block_control.manual.GetWordCount();
Log_DebugPrintf("DMA%u: Copying %u words %s 0x%08X", static_cast<u32>(channel), word_count,
copy_to_device ? "from" : "to", current_address & mask);
Log_DebugFmt("DMA[{}]: Copying {} words {} 0x{:08X}", channel, word_count, copy_to_device ? "from" : "to",
current_address);
const PhysicalMemoryAddress transfer_addr = current_address & TRANSFER_ADDRESS_MASK;
if (CheckForBusError(channel, cs, transfer_addr, word_count * sizeof(u32))) [[unlikely]]
return true;
TickCount used_ticks;
if (copy_to_device)
used_ticks = TransferMemoryToDevice<channel>(current_address & mask, increment, word_count);
used_ticks = TransferMemoryToDevice<channel>(transfer_addr, increment, word_count);
else
used_ticks = TransferDeviceToMemory<channel>(current_address & mask, increment, word_count);
used_ticks = TransferDeviceToMemory<channel>(transfer_addr, increment, word_count);
CPU::AddPendingTicks(used_ticks);
CompleteTransfer(channel, cs);
return true;
}
break;
case SyncMode::LinkedList:
{
@ -564,43 +616,53 @@ bool DMA::TransferChannel()
return true;
}
Log_DebugPrintf("DMA%u: Copying linked list starting at 0x%08X to device", static_cast<u32>(channel),
current_address & mask);
Log_DebugFmt("DMA[{}]: Copying linked list starting at 0x{:08X} to device", channel, current_address);
// Prove to the compiler that nothing's going to modify these.
const u8* const ram_ptr = Bus::g_ram;
const u32 mask = Bus::g_ram_mask;
u8* ram_pointer = Bus::g_ram;
TickCount remaining_ticks = GetTransferSliceTicks();
while (cs.request && remaining_ticks > 0)
{
u32 header;
std::memcpy(&header, &ram_pointer[current_address & mask], sizeof(header));
CPU::AddPendingTicks(10);
remaining_ticks -= 10;
PhysicalMemoryAddress transfer_addr = current_address & TRANSFER_ADDRESS_MASK;
if (CheckForBusError(channel, cs, current_address, sizeof(header))) [[unlikely]]
{
cs.base_address = current_address;
return true;
}
std::memcpy(&header, &ram_ptr[transfer_addr & mask], sizeof(header));
const u32 word_count = header >> 24;
const u32 next_address = header & UINT32_C(0x00FFFFFF);
Log_TracePrintf(" .. linked list entry at 0x%08X size=%u(%u words) next=0x%08X", current_address & mask,
word_count * UINT32_C(4), word_count, next_address);
const u32 next_address = header & 0x00FFFFFFu;
Log_TraceFmt(" .. linked list entry at 0x{:08X} size={}({} words) next=0x{:08X}", current_address,
word_count * 4, word_count, next_address);
const TickCount setup_ticks = (word_count > 0) ?
(LINKED_LIST_HEADER_READ_TICKS + LINKED_LIST_BLOCK_SETUP_TICKS) :
LINKED_LIST_HEADER_READ_TICKS;
CPU::AddPendingTicks(setup_ticks);
remaining_ticks -= setup_ticks;
if (word_count > 0)
{
CPU::AddPendingTicks(5);
remaining_ticks -= 5;
const TickCount block_ticks =
TransferMemoryToDevice<channel>((current_address + sizeof(header)) & mask, 4, word_count);
const TickCount block_ticks = TransferMemoryToDevice<channel>(transfer_addr + sizeof(header), 4, word_count);
CPU::AddPendingTicks(block_ticks);
remaining_ticks -= block_ticks;
}
current_address = next_address;
if (current_address & UINT32_C(0x800000))
break;
if (IsLinkedListTerminator(current_address))
{
// Terminator is 24 bits, so is MADR, so it'll always be 0xFFFFFF.
cs.base_address = LINKED_LIST_TERMINATOR;
CompleteTransfer(channel, cs);
return true;
}
}
cs.base_address = current_address;
if (current_address & UINT32_C(0x800000))
break;
if (cs.request)
{
// stall the transfer for a bit if we ran for too long
@ -613,7 +675,6 @@ bool DMA::TransferChannel()
return true;
}
}
break;
case SyncMode::Request:
{
@ -630,30 +691,46 @@ bool DMA::TransferChannel()
{
do
{
const PhysicalMemoryAddress transfer_addr = current_address & TRANSFER_ADDRESS_MASK;
if (CheckForBusError(channel, cs, transfer_addr, block_size * increment)) [[unlikely]]
{
cs.base_address = current_address;
cs.block_control.request.block_count = blocks_remaining;
return true;
}
const TickCount ticks = TransferMemoryToDevice<channel>(transfer_addr, increment, block_size);
CPU::AddPendingTicks(ticks);
ticks_remaining -= ticks;
blocks_remaining--;
const TickCount ticks = TransferMemoryToDevice<channel>(current_address & mask, increment, block_size);
CPU::AddPendingTicks(ticks);
ticks_remaining -= ticks;
current_address = (current_address + (increment * block_size));
current_address = (transfer_addr + (increment * block_size));
} while (cs.request && blocks_remaining > 0 && ticks_remaining > 0);
}
else
{
do
{
const PhysicalMemoryAddress transfer_addr = current_address & TRANSFER_ADDRESS_MASK;
if (CheckForBusError(channel, cs, transfer_addr, block_size * increment)) [[unlikely]]
{
cs.base_address = current_address;
cs.block_control.request.block_count = blocks_remaining;
return true;
}
const TickCount ticks = TransferDeviceToMemory<channel>(transfer_addr, increment, block_size);
CPU::AddPendingTicks(ticks);
ticks_remaining -= ticks;
blocks_remaining--;
const TickCount ticks = TransferDeviceToMemory<channel>(current_address & mask, increment, block_size);
CPU::AddPendingTicks(ticks);
ticks_remaining -= ticks;
current_address = (current_address + (increment * block_size));
current_address = (transfer_addr + (increment * block_size));
} while (cs.request && blocks_remaining > 0 && ticks_remaining > 0);
}
cs.base_address = current_address & BASE_ADDRESS_MASK;
cs.base_address = current_address;
cs.block_control.request.block_count = blocks_remaining;
// finish transfer later if the request was cleared
@ -670,25 +747,16 @@ bool DMA::TransferChannel()
return true;
}
CompleteTransfer(channel, cs);
return true;
}
break;
default:
Panic("Unimplemented sync mode");
break;
}
// start/busy bit is cleared on end of transfer
Log_DebugFmt("DMA transfer for channel {} complete", channel);
cs.channel_control.enable_busy = false;
if (s_DICR.IsIRQEnabled(channel))
{
Log_DebugFmt("Setting DMA interrupt for channel {}", channel);
s_DICR.SetIRQFlag(channel);
UpdateIRQ();
}
return true;
UnreachableCode();
}
void DMA::HaltTransfer(TickCount duration)
@ -726,8 +794,15 @@ void DMA::UnhaltTransfer(void*, TickCount ticks, TickCount ticks_late)
template<DMA::Channel channel>
TickCount DMA::TransferMemoryToDevice(u32 address, u32 increment, u32 word_count)
{
const u32 mask = Bus::g_ram_mask;
#ifdef _DEBUG
if ((address & mask) != address)
Log_DebugFmt("DMA TO {} from masked RAM address 0x{:08X} => 0x{:08X}", channel, address, (address & mask));
#endif
address &= mask;
const u32* src_pointer = reinterpret_cast<u32*>(Bus::g_ram + address);
const u32 mask = GetAddressMask();
if constexpr (channel != Channel::GPU)
{
if (static_cast<s32>(increment) < 0 || ((address + (increment * word_count)) & mask) <= address) [[unlikely]]
@ -787,7 +862,14 @@ TickCount DMA::TransferMemoryToDevice(u32 address, u32 increment, u32 word_count
template<DMA::Channel channel>
TickCount DMA::TransferDeviceToMemory(u32 address, u32 increment, u32 word_count)
{
const u32 mask = GetAddressMask();
const u32 mask = Bus::g_ram_mask;
#ifdef _DEBUG
if ((address & mask) != address)
Log_DebugFmt("DMA FROM {} to masked RAM address 0x{:08X} => 0x{:08X}", channel, address, (address & mask));
#endif
// TODO: This might not be correct for OTC.
address &= mask;
if constexpr (channel == Channel::OTC)
{
@ -796,9 +878,9 @@ TickCount DMA::TransferDeviceToMemory(u32 address, u32 increment, u32 word_count
const u32 word_count_less_1 = word_count - 1;
for (u32 i = 0; i < word_count_less_1; i++)
{
u32 value = ((address - 4) & mask);
std::memcpy(&ram_pointer[address], &value, sizeof(value));
address = (address - 4) & mask;
u32 next = ((address - 4) & mask);
std::memcpy(&ram_pointer[address], &next, sizeof(next));
address = next;
}
const u32 terminator = UINT32_C(0xFFFFFF);
@ -918,8 +1000,8 @@ void DMA::DrawDebugStateWindow()
ImGui::TextColored(s_DPCR.GetMasterEnable(static_cast<Channel>(i)) ? active : inactive, "%u",
s_DPCR.GetPriority(static_cast<Channel>(i)));
ImGui::NextColumn();
ImGui::TextColored(s_DICR.IsIRQEnabled(static_cast<Channel>(i)) ? active : inactive,
s_DICR.IsIRQEnabled(static_cast<Channel>(i)) ? "Enabled" : "Disabled");
ImGui::TextColored(s_DICR.GetIRQEnabled(static_cast<Channel>(i)) ? active : inactive,
s_DICR.GetIRQEnabled(static_cast<Channel>(i)) ? "Enabled" : "Disabled");
ImGui::NextColumn();
ImGui::TextColored(s_DICR.GetIRQFlag(static_cast<Channel>(i)) ? active : inactive,
s_DICR.GetIRQFlag(static_cast<Channel>(i)) ? "IRQ" : "");