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dingusppc/devices/common/dbdma.cpp

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/*
DingusPPC - The Experimental PowerPC Macintosh emulator
Copyright (C) 2018-23 divingkatae and maximum
(theweirdo) spatium
(Contact divingkatae#1017 or powermax#2286 on Discord for more info)
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
/** @file Descriptor-based direct memory access emulation. */
#include <cpu/ppc/ppcmmu.h>
#include <devices/common/dbdma.h>
#include <devices/common/dmacore.h>
#include <devices/common/hwinterrupt.h>
#include <devices/common/mmiodevice.h>
#include <endianswap.h>
#include <memaccess.h>
#include <cinttypes>
#include <cstring>
#include <loguru.hpp>
void DMAChannel::set_callbacks(DbdmaCallback start_cb, DbdmaCallback stop_cb) {
this->start_cb = start_cb;
this->stop_cb = stop_cb;
}
/* Load DMACmd from physical memory. */
void DMAChannel::fetch_cmd(uint32_t cmd_addr, DMACmd* p_cmd) {
MapDmaResult res = mmu_map_dma_mem(cmd_addr, 16, false);
memcpy((uint8_t*)p_cmd, res.host_va, 16);
}
uint8_t DMAChannel::interpret_cmd() {
DMACmd cmd_struct;
MapDmaResult res;
if (this->cmd_in_progress) {
// return current command if there is data to transfer
if (this->queue_len)
return this->cur_cmd;
this->finish_cmd();
}
fetch_cmd(this->cmd_ptr, &cmd_struct);
this->ch_stat &= ~CH_STAT_WAKE; // clear wake bit (DMA spec, 5.5.3.4)
this->cur_cmd = cmd_struct.cmd_key >> 4;
switch (this->cur_cmd) {
case DBDMA_Cmd::OUTPUT_MORE:
case DBDMA_Cmd::OUTPUT_LAST:
case DBDMA_Cmd::INPUT_MORE:
case DBDMA_Cmd::INPUT_LAST:
if (cmd_struct.cmd_key & 7) {
LOG_F(ERROR, "Key > 0 not implemented");
break;
}
res = mmu_map_dma_mem(cmd_struct.address, cmd_struct.req_count, false);
this->queue_data = res.host_va;
this->queue_len = cmd_struct.req_count;
this->cmd_in_progress = true;
break;
case DBDMA_Cmd::STORE_QUAD:
if ((cmd_struct.cmd_key & 7) != 6)
LOG_F(9, "Invalid key %d in STORE_QUAD", cmd_struct.cmd_key & 7);
this->xfer_quad(&cmd_struct, true);
break;
case DBDMA_Cmd::LOAD_QUAD:
if ((cmd_struct.cmd_key & 7) != 6)
LOG_F(9, "Invalid key %d in LOAD_QUAD", cmd_struct.cmd_key & 7);
this->xfer_quad(&cmd_struct, false);
break;
case DBDMA_Cmd::NOP:
this->finish_cmd();
break;
case DBDMA_Cmd::STOP:
this->ch_stat &= ~CH_STAT_ACTIVE;
this->cmd_in_progress = false;
break;
default:
LOG_F(ERROR, "Unsupported DMA command 0x%X", this->cur_cmd);
this->ch_stat |= CH_STAT_DEAD;
this->ch_stat &= ~CH_STAT_ACTIVE;
}
return this->cur_cmd;
}
void DMAChannel::finish_cmd() {
DMACmd cmd_struct;
bool branch_taken = false;
// obtain real pointer to the descriptor of the command to be finished
MapDmaResult res = mmu_map_dma_mem(this->cmd_ptr, 16, false);
uint8_t *cmd_desc = res.host_va;
// get command code
this->cur_cmd = cmd_desc[3] >> 4;
// all commands except STOP update cmd.xferStatus and
// perform actions under control of "i", "b" and "w" bits
if (this->cur_cmd < DBDMA_Cmd::STOP) {
// react to cmd.w (wait) bits
if (cmd_desc[2] & 3) {
bool cond = true;
if ((cmd_desc[2] & 3) != 3) {
uint16_t wt_mask = this->wait_select >> 16;
cond = (this->ch_stat & wt_mask) == (this->wait_select & wt_mask);
if ((cmd_desc[2] & 3) == 2) {
cond = !cond; // wait if cond = false
}
}
if (cond)
return;
}
if (res.is_writable)
WRITE_WORD_LE_A(&cmd_desc[14], this->ch_stat | CH_STAT_ACTIVE);
// react to cmd.b (branch) bits
if (cmd_desc[2] & 0xC) {
bool cond = true;
if ((cmd_desc[2] & 0xC) != 0xC) {
uint16_t br_mask = this->branch_select >> 16;
cond = (this->ch_stat & br_mask) == (this->branch_select & br_mask);
if ((cmd_desc[2] & 0xC) == 0x8) {
cond = !cond; // branch if cond = false
}
}
if (cond) {
this->cmd_ptr = READ_DWORD_LE_A(&cmd_desc[8]);
branch_taken = true;
}
}
this->update_irq();
}
// all INPUT and OUTPUT commands update cmd.resCount
if (this->cur_cmd < DBDMA_Cmd::STORE_QUAD && res.is_writable) {
WRITE_WORD_LE_A(&cmd_desc[12], this->queue_len & 0xFFFFUL);
}
if (!branch_taken)
this->cmd_ptr += 16;
this->cmd_in_progress = false;
}
void DMAChannel::xfer_quad(const DMACmd *cmd_desc, const bool is_store) {
MapDmaResult res;
uint8_t *src, *dst;
uint32_t addr;
// parse and fix reqCount
uint32_t xfer_size = cmd_desc->req_count & 7;
if (xfer_size & 4) {
xfer_size = 4;
} else if (xfer_size & 2) {
xfer_size = 2;
} else {
xfer_size = 1;
}
addr = cmd_desc->address & ~(xfer_size - 1);
// prepare data pointers and perform data transfer
if (is_store) {
res = mmu_map_dma_mem(this->cmd_ptr, 16, false);
src = res.host_va + 8; // move src to cmd.data32
res = mmu_map_dma_mem(addr, xfer_size, true);
if (res.type & RT_MMIO) {
res.dev_obj->write(res.dev_base, addr - res.dev_base,
read_mem_rev(src, xfer_size), xfer_size);
} else if (res.is_writable) {
std::memcpy(res.host_va, src, xfer_size);
}
} else {
res = mmu_map_dma_mem(this->cmd_ptr, 16, false);
if (res.is_writable) {
dst = res.host_va + 8; // move dst to cmd.data32
res = mmu_map_dma_mem(addr, xfer_size, true);
if (res.type & RT_MMIO) {
write_mem_rev(dst,
res.dev_obj->read(res.dev_base, addr - res.dev_base, xfer_size),
xfer_size);
} else {
std::memcpy(dst, res.host_va, xfer_size);
}
}
}
if (cmd_desc->cmd_bits & 0xC)
ABORT_F("DBDMA: cmd_bits.b should be zero for LOAD/STORE_QUAD!");
this->finish_cmd();
}
void DMAChannel::update_irq() {
// obtain real pointer to the descriptor of the completed command
MapDmaResult res = mmu_map_dma_mem(this->cmd_ptr, 16, false);
uint8_t *cmd_desc = res.host_va;
// STOP doesn't generate interrupts
if (this->cur_cmd < DBDMA_Cmd::STOP) {
// react to cmd.i (interrupt) bits
if (cmd_desc[2] & 0x30) {
bool cond = true;
if ((cmd_desc[2] & 0x30) != 0x30) {
uint16_t int_mask = this->int_select >> 16;
cond = (this->ch_stat & int_mask) == (this->int_select & int_mask);
if ((cmd_desc[2] & 0x30) == 0x20) {
cond = !cond; // generate interrupt if cond = false
}
}
if (cond) {
this->int_ctrl->ack_dma_int(this->irq_id, 1);
}
}
}
}
uint32_t DMAChannel::reg_read(uint32_t offset, int size) {
if (size != 4) {
ABORT_F("DBDMA: non-DWORD read from a DMA channel not supported");
}
switch (offset) {
case DMAReg::CH_CTRL:
return 0; // ChannelControl reads as 0 (DBDMA spec 5.5.1, table 74)
case DMAReg::CH_STAT:
return BYTESWAP_32(this->ch_stat);
case DMAReg::CMD_PTR_LO:
return BYTESWAP_32(this->cmd_ptr);
default:
LOG_F(WARNING, "Unsupported DMA channel register 0x%X", offset);
}
return 0;
}
void DMAChannel::reg_write(uint32_t offset, uint32_t value, int size) {
uint16_t mask, old_stat, new_stat;
if (size != 4) {
ABORT_F("DBDMA: non-DWORD writes to a DMA channel not supported");
}
value = BYTESWAP_32(value);
old_stat = this->ch_stat;
switch (offset) {
case DMAReg::CH_CTRL:
mask = value >> 16;
new_stat = (value & mask & 0xF0FFU) | (old_stat & ~mask);
LOG_F(9, "New ChannelStatus value = 0x%X", new_stat);
// update ch_stat.s0...s7 if requested (needed for interrupt generation)
if ((new_stat & 0xFF) != (old_stat & 0xFF)) {
this->ch_stat |= new_stat & 0xFF;
}
// flush bit can be set at the same time the run bit is cleared.
// That means we need to update memory before channel operation
// is aborted to prevent data loss.
if (new_stat & CH_STAT_FLUSH) {
// NOTE: because this implementation doesn't currently support
// partial memory updates no special action is taken here
new_stat &= ~CH_STAT_FLUSH;
this->ch_stat = new_stat;
}
if ((new_stat & CH_STAT_RUN) != (old_stat & CH_STAT_RUN)) {
if (new_stat & CH_STAT_RUN) {
new_stat |= CH_STAT_ACTIVE;
this->ch_stat = new_stat;
this->start();
} else {
this->abort();
this->update_irq();
new_stat &= ~CH_STAT_ACTIVE;
new_stat &= ~CH_STAT_DEAD;
this->cmd_in_progress = false;
this->ch_stat = new_stat;
}
} else if ((new_stat & CH_STAT_WAKE) != (old_stat & CH_STAT_WAKE)) {
new_stat |= CH_STAT_ACTIVE;
this->ch_stat = new_stat;
this->resume();
} else if ((new_stat & CH_STAT_PAUSE) != (old_stat & CH_STAT_PAUSE)) {
if (new_stat & CH_STAT_PAUSE) {
new_stat &= ~CH_STAT_ACTIVE;
this->ch_stat = new_stat;
this->pause();
}
}
break;
case DMAReg::CH_STAT:
break; // ingore writes to ChannelStatus
case DMAReg::CMD_PTR_HI: // Mac OS X writes this optional register with zero
LOG_F(9, "CommandPtrHi set to 0x%X", value);
break;
case DMAReg::CMD_PTR_LO:
if (!(this->ch_stat & CH_STAT_RUN) && !(this->ch_stat & CH_STAT_ACTIVE)) {
this->cmd_ptr = value;
LOG_F(9, "CommandPtrLo set to 0x%X", this->cmd_ptr);
}
break;
case DMAReg::INT_SELECT:
this->int_select = value & 0xFF00FFUL;
break;
case DMAReg::BRANCH_SELECT:
this->branch_select = value & 0xFF00FFUL;
break;
case DMAReg::WAIT_SELECT:
this->wait_select = value & 0xFF00FFUL;
break;
default:
LOG_F(WARNING, "Unsupported DMA channel register 0x%X", offset);
}
}
DmaPullResult DMAChannel::pull_data(uint32_t req_len, uint32_t *avail_len, uint8_t **p_data)
{
*avail_len = 0;
if (this->ch_stat & CH_STAT_DEAD || !(this->ch_stat & CH_STAT_ACTIVE)) {
// dead or idle channel? -> no more data
LOG_F(WARNING, "Dead/idle channel -> no more data");
return DmaPullResult::NoMoreData;
}
// interpret DBDMA program until we get data or become idle
while ((this->ch_stat & CH_STAT_ACTIVE) && !this->queue_len) {
this->interpret_cmd();
}
// dequeue data if any
if (this->queue_len) {
if (this->queue_len >= req_len) {
LOG_F(9, "Return req_len = %d data", req_len);
*p_data = this->queue_data;
*avail_len = req_len;
this->queue_len -= req_len;
this->queue_data += req_len;
} else { // return less data than req_len
LOG_F(9, "Return queue_len = %d data", this->queue_len);
*p_data = this->queue_data;
*avail_len = this->queue_len;
this->queue_len = 0;
}
return DmaPullResult::MoreData; // tell the caller there is more data
}
return DmaPullResult::NoMoreData; // tell the caller there is no more data
}
int DMAChannel::push_data(const char* src_ptr, int len) {
if (this->ch_stat & CH_STAT_DEAD || !(this->ch_stat & CH_STAT_ACTIVE)) {
LOG_F(WARNING, "DBDMA: attempt to push data to dead/idle channel");
return -1;
}
// interpret DBDMA program until we get buffer to fill in or become idle
while ((this->ch_stat & CH_STAT_ACTIVE) && !this->queue_len) {
this->interpret_cmd();
}
if (this->queue_len) {
len = std::min((int)this->queue_len, len);
std::memcpy(this->queue_data, src_ptr, len);
this->queue_data += len;
this->queue_len -= len;
}
// proceed with the DBDMA program if the buffer became exhausted
if (!this->queue_len) {
this->interpret_cmd();
}
return 0;
}
bool DMAChannel::is_active() {
if (this->ch_stat & CH_STAT_DEAD || !(this->ch_stat & CH_STAT_ACTIVE)) {
return false;
}
else {
return true;
}
}
void DMAChannel::start() {
if (this->ch_stat & CH_STAT_PAUSE) {
LOG_F(WARNING, "Cannot start DMA channel, PAUSE bit is set");
return;
}
this->queue_len = 0;
if (this->start_cb)
this->start_cb();
this->cmd_in_progress = false;
// some DBDMA programs contain commands that don't transfer data
// between a device and memory (LOAD_QUAD, STORE_QUAD, NOP and STOP).
// We thus interprete the DBDMA program until a data transfer between
// a device and memory is queued or the channel becomes idle/dead.
while (!this->cmd_in_progress && !(this->ch_stat & CH_STAT_DEAD) &&
(this->ch_stat & CH_STAT_ACTIVE)) {
this->interpret_cmd();
}
}
void DMAChannel::resume() {
if (this->ch_stat & CH_STAT_PAUSE) {
LOG_F(WARNING, "Cannot resume DMA channel, PAUSE bit is set");
return;
}
LOG_F(INFO, "Resuming DMA channel");
}
void DMAChannel::abort() {
LOG_F(9, "Aborting DMA channel");
if (this->stop_cb)
this->stop_cb();
}
void DMAChannel::pause() {
LOG_F(INFO, "Pausing DMA channel");
if (this->stop_cb)
this->stop_cb();
}
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