runtime: avoid hardcoding ethmac slot layout, use info from CSR.

This commit is contained in:
whitequark 2017-10-03 19:14:54 +00:00
parent a89b053473
commit e7dac530c1
1 changed files with 27 additions and 29 deletions

View File

@ -3,19 +3,19 @@ use board::{csr, mem};
use smoltcp::Error;
use smoltcp::phy::{DeviceLimits, Device};
const RX0_BASE: usize = mem::ETHMAC_BASE + 0x0000;
const RX1_BASE: usize = mem::ETHMAC_BASE + 0x0800;
const RX2_BASE: usize = mem::ETHMAC_BASE + 0x1000;
const RX3_BASE: usize = mem::ETHMAC_BASE + 0x1800;
const TX0_BASE: usize = mem::ETHMAC_BASE + 0x2000;
const TX1_BASE: usize = mem::ETHMAC_BASE + 0x2800;
const TX2_BASE: usize = mem::ETHMAC_BASE + 0x3000;
const TX3_BASE: usize = mem::ETHMAC_BASE + 0x3800;
const RX_SLOTS: usize = csr::ETHMAC_RX_SLOTS as usize;
const TX_SLOTS: usize = csr::ETHMAC_TX_SLOTS as usize;
const SLOT_SIZE: usize = csr::ETHMAC_SLOT_SIZE as usize;
const RX_BUFFERS: [*mut u8; 4] = [RX0_BASE as *mut u8, RX1_BASE as *mut u8,
RX2_BASE as *mut u8, RX3_BASE as *mut u8];
const TX_BUFFERS: [*mut u8; 4] = [TX0_BASE as *mut u8, TX1_BASE as *mut u8,
TX2_BASE as *mut u8, TX3_BASE as *mut u8];
fn rx_buffer(slot: usize) -> *const u8 {
debug_assert!(slot < RX_SLOTS);
(mem::ETHMAC_BASE + SLOT_SIZE * slot) as _
}
fn tx_buffer(slot: usize) -> *mut u8 {
debug_assert!(slot < TX_SLOTS);
(mem::ETHMAC_BASE + SLOT_SIZE * (RX_SLOTS + slot)) as _
}
pub struct EthernetDevice;
@ -26,35 +26,33 @@ impl Device for EthernetDevice {
fn limits(&self) -> DeviceLimits {
let mut limits = DeviceLimits::default();
limits.max_transmission_unit = 1514;
limits.max_burst_size = Some(RX_BUFFERS.len());
limits.max_burst_size = Some(RX_SLOTS);
limits
}
fn receive(&mut self, _timestamp: u64) -> Result<Self::RxBuffer, Error> {
unsafe {
if csr::ethmac::sram_writer_ev_pending_read() != 0 {
let slot = csr::ethmac::sram_writer_slot_read();
let length = csr::ethmac::sram_writer_length_read();
Ok(RxBuffer(slice::from_raw_parts(RX_BUFFERS[slot as usize],
length as usize)))
} else {
Err(Error::Exhausted)
if csr::ethmac::sram_writer_ev_pending_read() == 0 {
return Err(Error::Exhausted)
}
let slot = csr::ethmac::sram_writer_slot_read() as usize;
let length = csr::ethmac::sram_writer_length_read() as usize;
Ok(RxBuffer(slice::from_raw_parts(rx_buffer(slot), length)))
}
}
fn transmit(&mut self, _timestamp: u64, length: usize) -> Result<Self::TxBuffer, Error> {
unsafe {
if csr::ethmac::sram_reader_ready_read() != 0 {
let slot = csr::ethmac::sram_reader_slot_read();
let slot = (slot + 1) % (TX_BUFFERS.len() as u8);
csr::ethmac::sram_reader_slot_write(slot);
csr::ethmac::sram_reader_length_write(length as u16);
Ok(TxBuffer(slice::from_raw_parts_mut(TX_BUFFERS[slot as usize],
length as usize)))
} else {
Err(Error::Exhausted)
if csr::ethmac::sram_reader_ready_read() == 0 {
return Err(Error::Exhausted)
}
let slot = csr::ethmac::sram_reader_slot_read() as usize;
let slot = (slot + 1) % TX_SLOTS;
csr::ethmac::sram_reader_slot_write(slot as u8);
csr::ethmac::sram_reader_length_write(length as u16);
Ok(TxBuffer(slice::from_raw_parts_mut(tx_buffer(slot), length)))
}
}
}