/*
* SiFive Platform DMA emulation
*
* Copyright (c) 2020 Wind River Systems, Inc.
*
* Author:
* Bin Meng <bin.meng@windriver.com>
*
* 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 2 or
* (at your option) version 3 of the License.
*
* 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 <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include "qemu/bitops.h"
#include "qemu/log.h"
#include "qapi/error.h"
#include "hw/hw.h"
#include "hw/irq.h"
#include "hw/qdev-properties.h"
#include "hw/sysbus.h"
#include "migration/vmstate.h"
#include "sysemu/dma.h"
#include "hw/dma/sifive_pdma.h"
#define DMA_CONTROL 0x000
#define CONTROL_CLAIM BIT(0)
#define CONTROL_RUN BIT(1)
#define CONTROL_DONE_IE BIT(14)
#define CONTROL_ERR_IE BIT(15)
#define CONTROL_DONE BIT(30)
#define CONTROL_ERR BIT(31)
#define DMA_NEXT_CONFIG 0x004
#define CONFIG_REPEAT BIT(2)
#define CONFIG_ORDER BIT(3)
#define CONFIG_WRSZ_SHIFT 24
#define CONFIG_RDSZ_SHIFT 28
#define CONFIG_SZ_MASK 0xf
#define DMA_NEXT_BYTES 0x008
#define DMA_NEXT_DST 0x010
#define DMA_NEXT_SRC 0x018
#define DMA_EXEC_CONFIG 0x104
#define DMA_EXEC_BYTES 0x108
#define DMA_EXEC_DST 0x110
#define DMA_EXEC_SRC 0x118
enum dma_chan_state {
DMA_CHAN_STATE_IDLE,
DMA_CHAN_STATE_STARTED,
DMA_CHAN_STATE_ERROR,
DMA_CHAN_STATE_DONE
};
static void sifive_pdma_run(SiFivePDMAState *s, int ch)
{
uint64_t bytes = s->chan[ch].next_bytes;
uint64_t dst = s->chan[ch].next_dst;
uint64_t src = s->chan[ch].next_src;
uint32_t config = s->chan[ch].next_config;
int wsize, rsize, size;
uint8_t buf[64];
int n;
/* do nothing if bytes to transfer is zero */
if (!bytes) {
goto error;
}
/*
* The manual does not describe how the hardware behaviors when
* config.wsize and config.rsize are given different values.
* A common case is memory to memory DMA, and in this case they
* are normally the same. Abort if this expectation fails.
*/
wsize = (config >> CONFIG_WRSZ_SHIFT) & CONFIG_SZ_MASK;
rsize = (config >> CONFIG_RDSZ_SHIFT) & CONFIG_SZ_MASK;
if (wsize != rsize) {
goto error;
}
/*
* Calculate the transaction size
*
* size field is base 2 logarithm of DMA transaction size,
* but there is an upper limit of 64 bytes per transaction.
*/
size = wsize;
if (size > 6) {
size = 6;
}
size = 1 << size;
/* the bytes to transfer should be multiple of transaction size */
if (bytes % size) {
goto error;
}
/* indicate a DMA transfer is started */
s->chan[ch].state = DMA_CHAN_STATE_STARTED;
s->chan[ch].control &= ~CONTROL_DONE;
s->chan[ch].control &= ~CONTROL_ERR;
/* load the next_ registers into their exec_ counterparts */
s->chan[ch].exec_config = config;
s->chan[ch].exec_bytes = bytes;
s->chan[ch].exec_dst = dst;
s->chan[ch].exec_src = src;
for (n = 0; n < bytes / size; n++) {
cpu_physical_memory_read(s->chan[ch].exec_src, buf, size);
cpu_physical_memory_write(s->chan[ch].exec_dst, buf, size);
s->chan[ch].exec_src += size;
s->chan[ch].exec_dst += size;
s->chan[ch].exec_bytes -= size;
}
/* indicate a DMA transfer is done */
s->chan[ch].state = DMA_CHAN_STATE_DONE;
s->chan[ch].control &= ~CONTROL_RUN;
s->chan[ch].control |= CONTROL_DONE;
/* reload exec_ registers if repeat is required */
if (s->chan[ch].next_config & CONFIG_REPEAT) {
s->chan[ch].exec_bytes = bytes;
s->chan[ch].exec_dst = dst;
s->chan[ch].exec_src = src;
}
return;
error:
s->chan[ch].state = DMA_CHAN_STATE_ERROR;
s->chan[ch].control |= CONTROL_ERR;
return;
}
static inline void sifive_pdma_update_irq(SiFivePDMAState *s, int ch)
{
bool done_ie, err_ie;
done_ie = !!(s->chan[ch].control & CONTROL_DONE_IE);
err_ie = !!(s->chan[ch].control & CONTROL_ERR_IE);
if (done_ie && (s->chan[ch].control & CONTROL_DONE)) {
qemu_irq_raise(s->irq[ch * 2]);
} else {
qemu_irq_lower(s->irq[ch * 2]);
}
if (err_ie && (s->chan[ch].control & CONTROL_ERR)) {
qemu_irq_raise(s->irq[ch * 2 + 1]);
} else {
qemu_irq_lower(s->irq[ch * 2 + 1]);
}
s->chan[ch].state = DMA_CHAN_STATE_IDLE;
}
static uint64_t sifive_pdma_read(void *opaque, hwaddr offset, unsigned size)
{
SiFivePDMAState *s = opaque;
int ch = SIFIVE_PDMA_CHAN_NO(offset);
uint64_t val = 0;
if (ch >= SIFIVE_PDMA_CHANS) {
qemu_log_mask(LOG_GUEST_ERROR, "%s: Invalid channel no %d\n",
__func__, ch);
return 0;
}
offset &= 0xfff;
switch (offset) {
case DMA_CONTROL:
val = s->chan[ch].control;
break;
case DMA_NEXT_CONFIG:
val = s->chan[ch].next_config;
break;
case DMA_NEXT_BYTES:
val = s->chan[ch].next_bytes;
break;
case DMA_NEXT_DST:
val = s->chan[ch].next_dst;
break;
case DMA_NEXT_SRC:
val = s->chan[ch].next_src;
break;
case DMA_EXEC_CONFIG:
val = s->chan[ch].exec_config;
break;
case DMA_EXEC_BYTES:
val = s->chan[ch].exec_bytes;
break;
case DMA_EXEC_DST:
val = s->chan[ch].exec_dst;
break;
case DMA_EXEC_SRC:
val = s->chan[ch].exec_src;
break;
default:
qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset 0x%" HWADDR_PRIX "\n",
__func__, offset);
break;
}
return val;
}
static void sifive_pdma_write(void *opaque, hwaddr offset,
uint64_t value, unsigned size)
{
SiFivePDMAState *s = opaque;
int ch = SIFIVE_PDMA_CHAN_NO(offset);
if (ch >= SIFIVE_PDMA_CHANS) {
qemu_log_mask(LOG_GUEST_ERROR, "%s: Invalid channel no %d\n",
__func__, ch);
return;
}
offset &= 0xfff;
switch (offset) {
case DMA_CONTROL:
s->chan[ch].control = value;
if (value & CONTROL_RUN) {
sifive_pdma_run(s, ch);
}
sifive_pdma_update_irq(s, ch);
break;
case DMA_NEXT_CONFIG:
s->chan[ch].next_config = value;
break;
case DMA_NEXT_BYTES:
s->chan[ch].next_bytes = value;
break;
case DMA_NEXT_DST:
s->chan[ch].next_dst = value;
break;
case DMA_NEXT_SRC:
s->chan[ch].next_src = value;
break;
case DMA_EXEC_CONFIG:
case DMA_EXEC_BYTES:
case DMA_EXEC_DST:
case DMA_EXEC_SRC:
/* these are read-only registers */
break;
default:
qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset 0x%" HWADDR_PRIX "\n",
__func__, offset);
break;
}
}
static const MemoryRegionOps sifive_pdma_ops = {
.read = sifive_pdma_read,
.write = sifive_pdma_write,
.endianness = DEVICE_LITTLE_ENDIAN,
/* there are 32-bit and 64-bit wide registers */
.impl = {
.min_access_size = 4,
.max_access_size = 8,
}
};
static void sifive_pdma_realize(DeviceState *dev, Error **errp)
{
SiFivePDMAState *s = SIFIVE_PDMA(dev);
int i;
memory_region_init_io(&s->iomem, OBJECT(dev), &sifive_pdma_ops, s,
TYPE_SIFIVE_PDMA, SIFIVE_PDMA_REG_SIZE);
sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->iomem);
for (i = 0; i < SIFIVE_PDMA_IRQS; i++) {
sysbus_init_irq(SYS_BUS_DEVICE(dev), &s->irq[i]);
}
}
static void sifive_pdma_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
dc->desc = "SiFive Platform DMA controller";
dc->realize = sifive_pdma_realize;
}
static const TypeInfo sifive_pdma_info = {
.name = TYPE_SIFIVE_PDMA,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(SiFivePDMAState),
.class_init = sifive_pdma_class_init,
};
static void sifive_pdma_register_types(void)
{
type_register_static(&sifive_pdma_info);
}
type_init(sifive_pdma_register_types)
