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IDEDiskDevice: Implement basic DMA writes.

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This could share more code with reads, and generally be better. But it works
and it's considerably faster than PIO, so let's use it. :^)
This commit is contained in:
Andreas Kling 2019-05-26 14:58:21 +02:00
parent dd595fe865
commit bb288c1baf
2 changed files with 79 additions and 3 deletions
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75
Kernel/Devices/IDEDiskDevice.cpp
View file

@ -120,6 +120,8 @@ bool IDEDiskDevice::read_block(unsigned index, byte* out) const
bool IDEDiskDevice::write_blocks(unsigned index, word count, const byte* data)
{
if (m_bus_master_base && m_dma_enabled.resource())
return write_sectors_with_dma(index, count, data);
for (unsigned i = 0; i < count; ++i) {
if (!write_sectors(index + i, 1, data + i * 512))
return false;
@ -374,6 +376,79 @@ bool IDEDiskDevice::read_sectors(dword start_sector, word count, byte* outbuf)
return true;
}
bool IDEDiskDevice::write_sectors_with_dma(dword lba, word count, const byte* inbuf)
{
LOCKER(m_lock);
#ifdef DISK_DEBUG
dbgprintf("%s(%u): IDEDiskDevice::write_sectors_with_dma (%u x%u) <- %p\n",
current->process().name().characters(),
current->pid(), lba, count, inbuf);
#endif
disable_irq();
m_prdt.offset = m_dma_buffer_page->paddr();
m_prdt.size = 512 * count;
memcpy(m_dma_buffer_page->paddr().as_ptr(), inbuf, 512 * count);
ASSERT(m_prdt.size <= PAGE_SIZE);
// Stop bus master
IO::out8(m_bus_master_base, 0);
// Write the PRDT location
IO::out32(m_bus_master_base + 4, (dword)&m_prdt);
// Turn on "Interrupt" and "Error" flag. The error flag should be cleared by hardware.
IO::out8(m_bus_master_base + 2, IO::in8(m_bus_master_base + 2) | 0x6);
m_interrupted = false;
enable_irq();
while (IO::in8(m_io_base + ATA_REG_STATUS) & ATA_SR_BSY);
bool is_slave = false;
IO::out8(m_io_base + ATA_REG_CONTROL, 0);
IO::out8(m_io_base + ATA_REG_HDDEVSEL, 0xe0 | (is_slave << 4));
wait_400ns(m_io_base);
IO::out8(m_io_base + ATA_REG_FEATURES, 0);
IO::out8(m_io_base + ATA_REG_SECCOUNT0, 0);
IO::out8(m_io_base + ATA_REG_LBA0, 0);
IO::out8(m_io_base + ATA_REG_LBA1, 0);
IO::out8(m_io_base + ATA_REG_LBA2, 0);
IO::out8(m_io_base + ATA_REG_SECCOUNT0, count);
IO::out8(m_io_base + ATA_REG_LBA0, (lba & 0x000000ff) >> 0);
IO::out8(m_io_base + ATA_REG_LBA1, (lba & 0x0000ff00) >> 8);
IO::out8(m_io_base + ATA_REG_LBA2, (lba & 0x00ff0000) >> 16);
for (;;) {
auto status = IO::in8(m_io_base + ATA_REG_STATUS);
if (!(status & ATA_SR_BSY) && (status & ATA_SR_DRDY))
break;
}
IO::out8(m_io_base + ATA_REG_COMMAND, ATA_CMD_WRITE_DMA_EXT);
wait_400ns(m_io_base);
// Start bus master
IO::out8(m_bus_master_base, 0x1);
wait_for_irq();
disable_irq();
if (m_device_error)
return false;
// I read somewhere that this may trigger a cache flush so let's do it.
IO::out8(m_bus_master_base + 2, IO::in8(m_bus_master_base + 2) | 0x6);
return true;
}
bool IDEDiskDevice::write_sectors(dword start_sector, word count, const byte* data)
{
ASSERT(count <= 256);

7
Kernel/Devices/IDEDiskDevice.h
View file

@ -39,9 +39,10 @@ private:
void initialize();
bool wait_for_irq();
bool read_sectors_with_dma(dword sector, word count, byte*);
bool read_sectors(dword start_sector, word count, byte* buffer);
bool write_sectors(dword start_sector, word count, const byte* data);
bool read_sectors_with_dma(dword lba, word count, byte*);
bool write_sectors_with_dma(dword lba, word count, const byte*);
bool read_sectors(dword lba, word count, byte* buffer);
bool write_sectors(dword lba, word count, const byte* data);
Lock m_lock { "IDEDiskDevice" };
word m_cylinders { 0 };