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DMA: Simplify address masking

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This commit is contained in:
Connor McLaughlin 2019-11-11 20:34:41 +10:00
parent 6f4cf7d5e3
commit 29674df803
2 changed files with 16 additions and 14 deletions
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27
src/core/dma.cpp
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@ -105,7 +105,7 @@ void DMA::WriteRegister(u32 offset, u32 value)
{ {
case 0x00: case 0x00:
{ {
state.base_address = value & ADDRESS_MASK; state.base_address = value & BASE_ADDRESS_MASK;
Log_TracePrintf("DMA channel %u base address <- 0x%08X", channel_index, state.base_address); Log_TracePrintf("DMA channel %u base address <- 0x%08X", channel_index, state.base_address);
return; return;
} }
@ -247,7 +247,7 @@ void DMA::TransferChannel(Channel channel)
// start/trigger bit is cleared on beginning of transfer // start/trigger bit is cleared on beginning of transfer
cs.channel_control.start_trigger = false; cs.channel_control.start_trigger = false;
PhysicalMemoryAddress current_address = (cs.base_address & ~UINT32_C(3)) & ADDRESS_MASK; PhysicalMemoryAddress current_address = cs.base_address;
const PhysicalMemoryAddress increment = cs.channel_control.address_step_reverse ? static_cast<u32>(-4) : UINT32_C(4); const PhysicalMemoryAddress increment = cs.channel_control.address_step_reverse ? static_cast<u32>(-4) : UINT32_C(4);
switch (cs.channel_control.sync_mode) switch (cs.channel_control.sync_mode)
{ {
@ -277,23 +277,24 @@ void DMA::TransferChannel(Channel channel)
for (;;) for (;;)
{ {
u32 header; u32 header;
m_bus->DispatchAccess<MemoryAccessType::Read, MemoryAccessSize::Word>(current_address, header); m_bus->DispatchAccess<MemoryAccessType::Read, MemoryAccessSize::Word>(current_address & ADDRESS_MASK, header);
const u32 word_count = header >> 24; const u32 word_count = header >> 24;
const u32 next_address = header & UINT32_C(0xFFFFFF); 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, Log_TracePrintf(" .. linked list entry at 0x%08X size=%u(%u words) next=0x%08X", current_address,
word_count * UINT32_C(4), word_count, next_address); word_count * UINT32_C(4), word_count, next_address);
current_address += sizeof(header); current_address += sizeof(header);
if (word_count > 0) if (word_count > 0)
TransferMemoryToDevice(channel, current_address, 4, word_count); TransferMemoryToDevice(channel, current_address & ADDRESS_MASK, 4, word_count);
if (next_address & UINT32_C(0x800000)) current_address = next_address;
if (current_address & UINT32_C(0x800000))
break; break;
current_address = next_address & ADDRESS_MASK;
} }
} }
cs.base_address = current_address;
} }
break; break;
@ -312,8 +313,8 @@ void DMA::TransferChannel(Channel channel)
do do
{ {
blocks_remaining--; blocks_remaining--;
TransferMemoryToDevice(channel, current_address, increment, block_size); TransferMemoryToDevice(channel, current_address & ADDRESS_MASK, increment, block_size);
current_address = (current_address + (increment * block_size)) & ADDRESS_MASK; current_address = (current_address + (increment * block_size));
} while (cs.request && blocks_remaining > 0); } while (cs.request && blocks_remaining > 0);
} }
else else
@ -321,12 +322,12 @@ void DMA::TransferChannel(Channel channel)
do do
{ {
blocks_remaining--; blocks_remaining--;
TransferDeviceToMemory(channel, current_address, increment, block_size); TransferDeviceToMemory(channel, current_address & ADDRESS_MASK, increment, block_size);
current_address = (current_address + (increment * block_size)) & ADDRESS_MASK; current_address = (current_address + (increment * block_size));
} while (cs.request && blocks_remaining > 0); } while (cs.request && blocks_remaining > 0);
} }
cs.base_address = current_address; cs.base_address = current_address & BASE_ADDRESS_MASK;
cs.block_control.request.block_count = blocks_remaining; cs.block_control.request.block_count = blocks_remaining;
// finish transfer later if the request was cleared // finish transfer later if the request was cleared

3
src/core/dma.h
View file

@ -49,7 +49,8 @@ public:
void SetGPU(GPU* gpu) { m_gpu = gpu; } void SetGPU(GPU* gpu) { m_gpu = gpu; }
private: private:
static constexpr PhysicalMemoryAddress ADDRESS_MASK = UINT32_C(0x00FFFFFF); static constexpr PhysicalMemoryAddress BASE_ADDRESS_MASK = UINT32_C(0x00FFFFFF);
static constexpr PhysicalMemoryAddress ADDRESS_MASK = UINT32_C(0x001FFFFC);
static constexpr u32 TRANSFER_TICKS = 10; static constexpr u32 TRANSFER_TICKS = 10;
enum class SyncMode : u32 enum class SyncMode : u32