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Kernel: Use rep insw/outsw for IDE transfers.

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There are much faster ways to do disk transfers, but I'm not implementing
those today. In the meantime, this is slightly nicer. :^)
This commit is contained in:
Andreas Kling 2019-04-23 03:45:55 +02:00
parent 37498c1566
commit 243e1d8462
2 changed files with 17 additions and 15 deletions
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21
Kernel/Devices/IDEDiskDevice.cpp
View file

@ -202,17 +202,12 @@ bool IDEDiskDevice::read_sectors(dword start_sector, word count, byte* outbuf)
return false; return false;
byte status = IO::in8(0x1f7); byte status = IO::in8(0x1f7);
if (status & DRQ) { ASSERT(status & DRQ);
#ifdef DISK_DEBUG #ifdef DISK_DEBUG
kprintf("Retrieving %u bytes (status=%b), outbuf=%p...\n", count * 512, status, outbuf); kprintf("Retrieving %u bytes (status=%b), outbuf=%p...\n", count * 512, status, outbuf);
#endif #endif
for (dword i = 0; i < (count * 512); i += 2) {
word w = IO::in16(IDE0_DATA);
outbuf[i] = LSB(w);
outbuf[i+1] = MSB(w);
}
}
IO::repeated_in16(IDE0_DATA, outbuf, count * 256);
return true; return true;
} }
@ -246,13 +241,8 @@ bool IDEDiskDevice::write_sectors(dword start_sector, word count, const byte* da
while (!(IO::in8(IDE0_STATUS) & DRQ)); while (!(IO::in8(IDE0_STATUS) & DRQ));
byte status = IO::in8(0x1f7); byte status = IO::in8(0x1f7);
if (status & DRQ) { ASSERT(status & DRQ);
//dbgprintf("Sending %u bytes (status=%b), data=%p...\n", count * 512, status, data); IO::repeated_out16(IDE0_DATA, data, count * 256);
auto* data_as_words = (const word*)data;
for (dword i = 0; i < (count * 512) / 2; ++i) {
IO::out16(IDE0_DATA, data_as_words[i]);
}
}
m_interrupted = false; m_interrupted = false;
enable_irq(); enable_irq();
@ -261,6 +251,7 @@ bool IDEDiskDevice::write_sectors(dword start_sector, word count, const byte* da
disable_irq(); disable_irq();
IO::out8(IDE0_COMMAND, FLUSH_CACHE); IO::out8(IDE0_COMMAND, FLUSH_CACHE);
while (IO::in8(IDE0_STATUS) & BUSY); while (IO::in8(IDE0_STATUS) & BUSY);
m_interrupted = false;
enable_irq(); enable_irq();
wait_for_irq(); wait_for_irq();

11
Kernel/IO.h
View file

@ -25,6 +25,11 @@ inline dword in32(word port)
return value; return value;
} }
inline void repeated_in16(word port, byte* buffer, int buffer_size)
{
asm volatile("rep insw" : "+D"(buffer), "+c"(buffer_size) : "d"(port) : "memory");
}
inline void out8(word port, byte value) inline void out8(word port, byte value)
{ {
asm volatile("outb %0, %1"::"a"(value), "Nd"(port)); asm volatile("outb %0, %1"::"a"(value), "Nd"(port));
@ -39,4 +44,10 @@ inline void out32(word port, dword value)
{ {
asm volatile("outl %0, %1"::"a"(value), "Nd"(port)); asm volatile("outl %0, %1"::"a"(value), "Nd"(port));
} }
inline void repeated_out16(word port, const byte* data, int data_size)
{
asm volatile("rep outsw" : "+S"(data), "+c"(data_size) : "d"(port));
}
} }