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IDEDiskDevice: Support reading multiple sectors at a time with DMA.

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This is another sizable improvement to GCC compile times.
This commit is contained in:
Andreas Kling 2019-05-19 04:40:30 +02:00
parent ed79116e94
commit c7d8aa6969
4 changed files with 27 additions and 14 deletions
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27
Kernel/Devices/IDEDiskDevice.cpp
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@ -6,6 +6,7 @@
#include "Scheduler.h"
#include "PIC.h"
#include <Kernel/Lock.h>
#include <Kernel/VM/MemoryManager.h>
//#define DISK_DEBUG
@ -126,10 +127,17 @@ unsigned IDEDiskDevice::block_size() const
return 512;
}
bool IDEDiskDevice::read_blocks(unsigned index, word count, byte* out)
{
if (m_bus_master_base)
return read_sectors_with_dma(index, count, out);
return read_sectors(index, count, out);
}
bool IDEDiskDevice::read_block(unsigned index, byte* out) const
{
if (m_bus_master_base)
return const_cast<IDEDiskDevice&>(*this).read_sector_with_dma(index, out);
return const_cast<IDEDiskDevice&>(*this).read_sectors_with_dma(index, 1, out);
return const_cast<IDEDiskDevice&>(*this).read_sectors(index, 1, out);
}
@ -248,6 +256,7 @@ void IDEDiskDevice::initialize()
m_prdt.end_of_table = 0x8000;
PCI::enable_bus_mastering(m_pci_address);
m_bus_master_base = PCI::get_BAR4(m_pci_address) & 0xfffc;
m_dma_buffer_page = MM.allocate_supervisor_physical_page();
dbgprintf("PIIX Bus master IDE: I/O @ %x\n", m_bus_master_base);
}
}
@ -258,19 +267,21 @@ static void wait_400ns(word io_base)
IO::in8(io_base + ATA_REG_ALTSTATUS);
}
bool IDEDiskDevice::read_sector_with_dma(dword lba, byte* outbuf)
bool IDEDiskDevice::read_sectors_with_dma(dword lba, word count, byte* outbuf)
{
LOCKER(m_lock);
#ifdef DISK_DEBUG
dbgprintf("%s(%u): IDEDiskDevice::read_sector_with_dma (%u) -> %p\n",
dbgprintf("%s(%u): IDEDiskDevice::read_sectors_with_dma (%u x%u) -> %p\n",
current->process().name().characters(),
current->pid(), lba, outbuf);
current->pid(), lba, count, outbuf);
#endif
disable_irq();
m_prdt.offset = PhysicalAddress((dword)outbuf);
m_prdt.size = 512;
m_prdt.offset = m_dma_buffer_page->paddr();
m_prdt.size = 512 * count;
ASSERT(m_prdt.size <= PAGE_SIZE);
// Stop bus master
IO::out8(m_bus_master_base, 0);
@ -303,7 +314,7 @@ bool IDEDiskDevice::read_sector_with_dma(dword lba, byte* outbuf)
IO::out8(io_base + ATA_REG_LBA1, 0);
IO::out8(io_base + ATA_REG_LBA2, 0);
IO::out8(io_base + ATA_REG_SECCOUNT0, 1);
IO::out8(io_base + ATA_REG_SECCOUNT0, count);
IO::out8(io_base + ATA_REG_LBA0, (lba & 0x000000ff) >> 0);
IO::out8(io_base + ATA_REG_LBA1, (lba & 0x0000ff00) >> 8);
IO::out8(io_base + ATA_REG_LBA2, (lba & 0x00ff0000) >> 16);
@ -326,6 +337,8 @@ bool IDEDiskDevice::read_sector_with_dma(dword lba, byte* outbuf)
if (m_device_error)
return false;
memcpy(outbuf, m_dma_buffer_page->paddr().as_ptr(), 512 * count);
// 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;