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IDE: Implement writing using Bus Mastering DMA

This commit is contained in:
TheOddGarlic 2022-08-17 17:19:27 +03:00
parent 9329059510
commit c6f7f7665c

View file

@ -76,9 +76,15 @@ const CMD_IDENTIFY: u8 = 0xEC;
/// ATA read using LBA28 DMA command
const CMD_READ_DMA: u8 = 0xC8;
/// ATA write using LBA28 DMA command
const CMD_WRITE_DMA: u8 = 0xCA;
/// ATA read using LBA48 DMA command
const CMD_READ_DMA_EXT: u8 = 0x25;
/// ATA write using LBA48 DMA command
const CMD_WRITE_DMA_EXT: u8 = 0x35;
pub struct PciIde {
device_info: PciDeviceInfo,
ide_devices: Vec<IdeDevice>,
@ -311,14 +317,14 @@ impl PciIde {
loop {
let status = unsafe { self.bmi_status(channel) };
// FIXME: error handling
// Bit 2 (INT) set?
if (status >> 2) & 1 == 1 {
break;
}
}
// FIXME: error handling
unsafe {
// Stop DMA
self.stop(channel);
@ -335,6 +341,91 @@ impl PciIde {
Ok(())
}
pub fn write(
&mut self,
channel: Channel,
drive: Drive,
lba: u64,
data: &[u8],
) -> Result<(), TryFromIntError> {
// FIXME: make this an error
assert!(data.len() % SECTOR_SIZE as usize == 0);
let lba48_support = self
.ide_devices
.iter()
.find(|d| d.channel == channel && d.drive == drive)
.map(|d| d.lba48_support)
.unwrap(); // FIXME: make this an error
let lba48 = lba > 0xFFFFFFF && lba48_support;
// FIXME: make this an error
assert!((lba48 && lba > 0xFFFFFFF) || (!lba48 && lba <= 0xFFFFFFF));
let byte_count = data.len() as u16;
let sector_count = byte_count / SECTOR_SIZE;
// prepare PRD table
let prd = PRDT_START as *mut PhysRegionDescriptor;
unsafe {
(*prd).data_buffer = self.buffer_frames.as_ref().unwrap()[0]
.start_address()
.as_u64()
.try_into()?;
(*prd).byte_count = byte_count;
// this is the end of table
(*prd).eot = 1 << 7;
// this byte is reserved, we should probably set it to 0
(*prd)._0 = 0;
}
// copy the data over to the DMA buffer
for i in 0..byte_count {
let addr = (BUFFER_START + i as u64) as *mut u8;
unsafe {
*addr = *data.get(i as usize).unwrap_or(&0);
}
}
unsafe {
self.load_prdt(channel);
self.stop(channel);
self.set_write(channel);
self.clear_bmi_status(channel);
select_drive(drive, channel);
set_lba(channel, lba, sector_count, lba48);
if lba48 {
ata_send_command(CMD_WRITE_DMA_EXT, channel);
} else {
ata_send_command(CMD_WRITE_DMA, channel);
}
self.start(channel);
}
loop {
let status = unsafe { self.bmi_status(channel) };
// FIXME: error handling
// Bit 2 (INT) set?
if (status >> 2) & 1 == 1 {
break;
}
}
unsafe {
// Stop DMA
self.stop(channel);
// Clear the interrupt bit
self.clear_bmi_status(channel);
}
Ok(())
}
pub fn device_info(&self) -> PciDeviceInfo {
self.device_info
}