zephyr/drivers/dma/dma_emul.c

618 lines
19 KiB
C

/*
* Copyright (c) 2023, Meta
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <errno.h>
#include <stdint.h>
#include <stdio.h>
#include <zephyr/device.h>
#include <zephyr/drivers/dma.h>
#include <zephyr/kernel.h>
#include <zephyr/logging/log.h>
#include <zephyr/pm/device.h>
#include <zephyr/sys/util.h>
#define DT_DRV_COMPAT zephyr_dma_emul
#ifdef CONFIG_DMA_64BIT
#define dma_addr_t uint64_t
#else
#define dma_addr_t uint32_t
#endif
enum dma_emul_channel_state {
DMA_EMUL_CHANNEL_UNUSED,
DMA_EMUL_CHANNEL_LOADED,
DMA_EMUL_CHANNEL_STARTED,
DMA_EMUL_CHANNEL_STOPPED,
};
struct dma_emul_xfer_desc {
struct dma_config config;
};
struct dma_emul_work {
const struct device *dev;
uint32_t channel;
struct k_work work;
};
struct dma_emul_config {
uint32_t channel_mask;
size_t num_channels;
size_t num_requests;
size_t addr_align;
size_t size_align;
size_t copy_align;
k_thread_stack_t *work_q_stack;
size_t work_q_stack_size;
int work_q_priority;
/* points to an array of size num_channels */
struct dma_emul_xfer_desc *xfer;
/* points to an array of size num_channels * num_requests */
struct dma_block_config *block;
};
struct dma_emul_data {
struct dma_context dma_ctx;
atomic_t *channels_atomic;
struct k_spinlock lock;
struct k_work_q work_q;
struct dma_emul_work work;
};
static void dma_emul_work_handler(struct k_work *work);
LOG_MODULE_REGISTER(dma_emul, CONFIG_DMA_LOG_LEVEL);
static inline bool dma_emul_xfer_is_error_status(int status)
{
return status < 0;
}
static inline const char *const dma_emul_channel_state_to_string(enum dma_emul_channel_state state)
{
switch (state) {
case DMA_EMUL_CHANNEL_UNUSED:
return "UNUSED";
case DMA_EMUL_CHANNEL_LOADED:
return "LOADED";
case DMA_EMUL_CHANNEL_STARTED:
return "STARTED";
case DMA_EMUL_CHANNEL_STOPPED:
return "STOPPED";
default:
return "(invalid)";
};
}
/*
* Repurpose the "_reserved" field for keeping track of internal
* channel state.
*
* Note: these must be called with data->lock locked!
*/
static enum dma_emul_channel_state dma_emul_get_channel_state(const struct device *dev,
uint32_t channel)
{
const struct dma_emul_config *config = dev->config;
__ASSERT_NO_MSG(channel < config->num_channels);
return (enum dma_emul_channel_state)config->xfer[channel].config._reserved;
}
static void dma_emul_set_channel_state(const struct device *dev, uint32_t channel,
enum dma_emul_channel_state state)
{
const struct dma_emul_config *config = dev->config;
LOG_DBG("setting channel %u state to %s", channel, dma_emul_channel_state_to_string(state));
__ASSERT_NO_MSG(channel < config->num_channels);
__ASSERT_NO_MSG(state >= DMA_EMUL_CHANNEL_UNUSED && state <= DMA_EMUL_CHANNEL_STOPPED);
config->xfer[channel].config._reserved = state;
}
static const char *dma_emul_xfer_config_to_string(const struct dma_config *cfg)
{
static char buffer[1024];
snprintf(buffer, sizeof(buffer),
"{"
"\n\tslot: %u"
"\n\tchannel_direction: %u"
"\n\tcomplete_callback_en: %u"
"\n\terror_callback_dis: %u"
"\n\tsource_handshake: %u"
"\n\tdest_handshake: %u"
"\n\tchannel_priority: %u"
"\n\tsource_chaining_en: %u"
"\n\tdest_chaining_en: %u"
"\n\tlinked_channel: %u"
"\n\tcyclic: %u"
"\n\t_reserved: %u"
"\n\tsource_data_size: %u"
"\n\tdest_data_size: %u"
"\n\tsource_burst_length: %u"
"\n\tdest_burst_length: %u"
"\n\tblock_count: %u"
"\n\thead_block: %p"
"\n\tuser_data: %p"
"\n\tdma_callback: %p"
"\n}",
cfg->dma_slot, cfg->channel_direction, cfg->complete_callback_en,
cfg->error_callback_dis, cfg->source_handshake, cfg->dest_handshake,
cfg->channel_priority, cfg->source_chaining_en, cfg->dest_chaining_en,
cfg->linked_channel, cfg->cyclic, cfg->_reserved, cfg->source_data_size,
cfg->dest_data_size, cfg->source_burst_length, cfg->dest_burst_length,
cfg->block_count, cfg->head_block, cfg->user_data, cfg->dma_callback);
return buffer;
}
static const char *dma_emul_block_config_to_string(const struct dma_block_config *cfg)
{
static char buffer[1024];
snprintf(buffer, sizeof(buffer),
"{"
"\n\tsource_address: %p"
"\n\tdest_address: %p"
"\n\tsource_gather_interval: %u"
"\n\tdest_scatter_interval: %u"
"\n\tdest_scatter_count: %u"
"\n\tsource_gather_count: %u"
"\n\tblock_size: %u"
"\n\tnext_block: %p"
"\n\tsource_gather_en: %u"
"\n\tdest_scatter_en: %u"
"\n\tsource_addr_adj: %u"
"\n\tdest_addr_adj: %u"
"\n\tsource_reload_en: %u"
"\n\tdest_reload_en: %u"
"\n\tfifo_mode_control: %u"
"\n\tflow_control_mode: %u"
"\n\t_reserved: %u"
"\n}",
(void *)cfg->source_address, (void *)cfg->dest_address,
cfg->source_gather_interval, cfg->dest_scatter_interval, cfg->dest_scatter_count,
cfg->source_gather_count, cfg->block_size, cfg->next_block, cfg->source_gather_en,
cfg->dest_scatter_en, cfg->source_addr_adj, cfg->dest_addr_adj,
cfg->source_reload_en, cfg->dest_reload_en, cfg->fifo_mode_control,
cfg->flow_control_mode, cfg->_reserved
);
return buffer;
}
static void dma_emul_work_handler(struct k_work *work)
{
size_t i;
size_t bytes;
uint32_t channel;
k_spinlock_key_t key;
struct dma_block_config block;
struct dma_config xfer_config;
enum dma_emul_channel_state state;
struct dma_emul_xfer_desc *xfer;
struct dma_emul_work *dma_work = CONTAINER_OF(work, struct dma_emul_work, work);
const struct device *dev = dma_work->dev;
struct dma_emul_data *data = dev->data;
const struct dma_emul_config *config = dev->config;
channel = dma_work->channel;
do {
key = k_spin_lock(&data->lock);
xfer = &config->xfer[channel];
/*
* copy the dma_config so we don't have to worry about
* it being asynchronously updated.
*/
memcpy(&xfer_config, &xfer->config, sizeof(xfer_config));
k_spin_unlock(&data->lock, key);
LOG_DBG("processing xfer %p for channel %u", xfer, channel);
for (i = 0; i < xfer_config.block_count; ++i) {
LOG_DBG("processing block %zu", i);
key = k_spin_lock(&data->lock);
/*
* copy the dma_block_config so we don't have to worry about
* it being asynchronously updated.
*/
memcpy(&block,
&config->block[channel * config->num_requests +
xfer_config.dma_slot + i],
sizeof(block));
k_spin_unlock(&data->lock, key);
/* transfer data in bursts */
for (bytes = MIN(block.block_size, xfer_config.dest_burst_length);
bytes > 0; block.block_size -= bytes, block.source_address += bytes,
block.dest_address += bytes,
bytes = MIN(block.block_size, xfer_config.dest_burst_length)) {
key = k_spin_lock(&data->lock);
state = dma_emul_get_channel_state(dev, channel);
k_spin_unlock(&data->lock, key);
if (state == DMA_EMUL_CHANNEL_STOPPED) {
LOG_DBG("asynchronously canceled");
if (!xfer_config.error_callback_dis) {
xfer_config.dma_callback(dev, xfer_config.user_data,
channel, -ECANCELED);
} else {
LOG_DBG("error_callback_dis is not set (async "
"cancel)");
}
goto out;
}
__ASSERT_NO_MSG(state == DMA_EMUL_CHANNEL_STARTED);
/*
* FIXME: create a backend API (memcpy, TCP/UDP socket, etc)
* Simple copy for now
*/
memcpy((void *)(uintptr_t)block.dest_address,
(void *)(uintptr_t)block.source_address, bytes);
}
}
key = k_spin_lock(&data->lock);
dma_emul_set_channel_state(dev, channel, DMA_EMUL_CHANNEL_STOPPED);
k_spin_unlock(&data->lock, key);
/* FIXME: tests/drivers/dma/chan_blen_transfer/ does not set complete_callback_en */
if (true) {
xfer_config.dma_callback(dev, xfer_config.user_data, channel,
DMA_STATUS_COMPLETE);
} else {
LOG_DBG("complete_callback_en is not set");
}
if (xfer_config.source_chaining_en || xfer_config.dest_chaining_en) {
LOG_DBG("%s(): Linked channel %u -> %u", __func__, channel,
xfer_config.linked_channel);
__ASSERT_NO_MSG(channel != xfer_config.linked_channel);
channel = xfer_config.linked_channel;
} else {
LOG_DBG("%s(): done!", __func__);
break;
}
} while (true);
out:
return;
}
static bool dma_emul_config_valid(const struct device *dev, uint32_t channel,
const struct dma_config *xfer_config)
{
size_t i;
struct dma_block_config *block;
const struct dma_emul_config *config = dev->config;
if (xfer_config->dma_slot >= config->num_requests) {
LOG_ERR("invalid dma_slot %u", xfer_config->dma_slot);
return false;
}
if (channel >= config->num_channels) {
LOG_ERR("invalid DMA channel %u", channel);
return false;
}
if (xfer_config->dest_burst_length != xfer_config->source_burst_length) {
LOG_ERR("burst length does not agree. source: %u dest: %u ",
xfer_config->source_burst_length, xfer_config->dest_burst_length);
return false;
}
for (i = 0, block = xfer_config->head_block; i < xfer_config->block_count;
++i, block = block->next_block) {
if (block == NULL) {
LOG_ERR("block %zu / %u is NULL", i + 1, xfer_config->block_count);
return false;
}
if (i >= config->num_requests) {
LOG_ERR("not enough slots to store block %zu / %u", i + 1,
xfer_config->block_count);
return false;
}
}
/*
* FIXME:
*
* Need to verify all of the fields in struct dma_config with different DT
* configurations so that the driver model is at least consistent and
* verified by CI.
*/
return true;
}
static int dma_emul_configure(const struct device *dev, uint32_t channel,
struct dma_config *xfer_config)
{
size_t i;
int ret = 0;
size_t block_idx;
k_spinlock_key_t key;
struct dma_block_config *block;
struct dma_block_config *block_it;
enum dma_emul_channel_state state;
struct dma_emul_xfer_desc *xfer;
struct dma_emul_data *data = dev->data;
const struct dma_emul_config *config = dev->config;
if (!dma_emul_config_valid(dev, channel, xfer_config)) {
return -EINVAL;
}
key = k_spin_lock(&data->lock);
xfer = &config->xfer[channel];
LOG_DBG("%s():\nchannel: %u\nconfig: %s", __func__, channel,
dma_emul_xfer_config_to_string(xfer_config));
block_idx = channel * config->num_requests + xfer_config->dma_slot;
block = &config->block[channel * config->num_requests + xfer_config->dma_slot];
state = dma_emul_get_channel_state(dev, channel);
switch (state) {
case DMA_EMUL_CHANNEL_UNUSED:
case DMA_EMUL_CHANNEL_STOPPED:
/* copy the configuration into the driver */
memcpy(&xfer->config, xfer_config, sizeof(xfer->config));
/* copy all blocks into slots */
for (i = 0, block_it = xfer_config->head_block; i < xfer_config->block_count;
++i, block_it = block_it->next_block, ++block) {
__ASSERT_NO_MSG(block_it != NULL);
LOG_DBG("block_config %s", dma_emul_block_config_to_string(block_it));
memcpy(block, block_it, sizeof(*block));
}
dma_emul_set_channel_state(dev, channel, DMA_EMUL_CHANNEL_LOADED);
break;
default:
LOG_ERR("attempt to configure DMA in state %d", state);
ret = -EBUSY;
}
k_spin_unlock(&data->lock, key);
return ret;
}
static int dma_emul_reload(const struct device *dev, uint32_t channel, dma_addr_t src,
dma_addr_t dst, size_t size)
{
LOG_DBG("%s()", __func__);
return -ENOSYS;
}
static int dma_emul_start(const struct device *dev, uint32_t channel)
{
int ret = 0;
k_spinlock_key_t key;
enum dma_emul_channel_state state;
struct dma_emul_xfer_desc *xfer;
struct dma_config *xfer_config;
struct dma_emul_data *data = dev->data;
const struct dma_emul_config *config = dev->config;
LOG_DBG("%s(channel: %u)", __func__, channel);
if (channel >= config->num_channels) {
return -EINVAL;
}
key = k_spin_lock(&data->lock);
xfer = &config->xfer[channel];
state = dma_emul_get_channel_state(dev, channel);
switch (state) {
case DMA_EMUL_CHANNEL_STARTED:
/* start after being started already is a no-op */
break;
case DMA_EMUL_CHANNEL_LOADED:
case DMA_EMUL_CHANNEL_STOPPED:
data->work.channel = channel;
while (true) {
dma_emul_set_channel_state(dev, channel, DMA_EMUL_CHANNEL_STARTED);
xfer_config = &config->xfer[channel].config;
if (xfer_config->source_chaining_en || xfer_config->dest_chaining_en) {
LOG_DBG("%s(): Linked channel %u -> %u", __func__, channel,
xfer_config->linked_channel);
channel = xfer_config->linked_channel;
} else {
break;
}
}
ret = k_work_submit_to_queue(&data->work_q, &data->work.work);
ret = (ret < 0) ? ret : 0;
break;
default:
LOG_ERR("attempt to start dma in invalid state %d", state);
ret = -EIO;
break;
}
k_spin_unlock(&data->lock, key);
return ret;
}
static int dma_emul_stop(const struct device *dev, uint32_t channel)
{
k_spinlock_key_t key;
struct dma_emul_data *data = dev->data;
key = k_spin_lock(&data->lock);
dma_emul_set_channel_state(dev, channel, DMA_EMUL_CHANNEL_STOPPED);
k_spin_unlock(&data->lock, key);
return 0;
}
static int dma_emul_suspend(const struct device *dev, uint32_t channel)
{
LOG_DBG("%s()", __func__);
return -ENOSYS;
}
static int dma_emul_resume(const struct device *dev, uint32_t channel)
{
LOG_DBG("%s()", __func__);
return -ENOSYS;
}
static int dma_emul_get_status(const struct device *dev, uint32_t channel,
struct dma_status *status)
{
LOG_DBG("%s()", __func__);
return -ENOSYS;
}
static int dma_emul_get_attribute(const struct device *dev, uint32_t type, uint32_t *value)
{
LOG_DBG("%s()", __func__);
return -ENOSYS;
}
static bool dma_emul_chan_filter(const struct device *dev, int channel, void *filter_param)
{
bool success;
k_spinlock_key_t key;
struct dma_emul_data *data = dev->data;
key = k_spin_lock(&data->lock);
/* lets assume the struct dma_context handles races properly */
success = dma_emul_get_channel_state(dev, channel) == DMA_EMUL_CHANNEL_UNUSED;
k_spin_unlock(&data->lock, key);
return success;
}
static const struct dma_driver_api dma_emul_driver_api = {
.config = dma_emul_configure,
.reload = dma_emul_reload,
.start = dma_emul_start,
.stop = dma_emul_stop,
.suspend = dma_emul_suspend,
.resume = dma_emul_resume,
.get_status = dma_emul_get_status,
.get_attribute = dma_emul_get_attribute,
.chan_filter = dma_emul_chan_filter,
};
#ifdef CONFIG_PM_DEVICE
static int gpio_emul_pm_device_pm_action(const struct device *dev, enum pm_device_action action)
{
ARG_UNUSED(dev);
ARG_UNUSED(action);
return 0;
}
#endif
static int dma_emul_init(const struct device *dev)
{
struct dma_emul_data *data = dev->data;
const struct dma_emul_config *config = dev->config;
data->work.dev = dev;
data->dma_ctx.magic = DMA_MAGIC;
data->dma_ctx.dma_channels = config->num_channels;
data->dma_ctx.atomic = data->channels_atomic;
k_work_queue_init(&data->work_q);
k_work_init(&data->work.work, dma_emul_work_handler);
k_work_queue_start(&data->work_q, config->work_q_stack, config->work_q_stack_size,
config->work_q_priority, NULL);
return 0;
}
#define DMA_EMUL_INST_HAS_PROP(_inst, _prop) DT_NODE_HAS_PROP(DT_DRV_INST(_inst), _prop)
#define DMA_EMUL_INST_CHANNEL_MASK(_inst) \
DT_INST_PROP_OR(_inst, dma_channel_mask, \
DMA_EMUL_INST_HAS_PROP(_inst, dma_channels) \
? ((DT_INST_PROP(_inst, dma_channels) > 0) \
? BIT_MASK(DT_INST_PROP_OR(_inst, dma_channels, 0)) \
: 0) \
: 0)
#define DMA_EMUL_INST_NUM_CHANNELS(_inst) \
DT_INST_PROP_OR(_inst, dma_channels, \
DMA_EMUL_INST_HAS_PROP(_inst, dma_channel_mask) \
? POPCOUNT(DT_INST_PROP_OR(_inst, dma_channel_mask, 0)) \
: 0)
#define DMA_EMUL_INST_NUM_REQUESTS(_inst) DT_INST_PROP_OR(_inst, dma_requests, 1)
#define DEFINE_DMA_EMUL(_inst) \
BUILD_ASSERT(DMA_EMUL_INST_HAS_PROP(_inst, dma_channel_mask) || \
DMA_EMUL_INST_HAS_PROP(_inst, dma_channels), \
"at least one of dma_channel_mask or dma_channels must be provided"); \
\
BUILD_ASSERT(DMA_EMUL_INST_NUM_CHANNELS(_inst) <= 32, "invalid dma-channels property"); \
\
static K_THREAD_STACK_DEFINE(work_q_stack_##_inst, DT_INST_PROP(_inst, stack_size)); \
\
static struct dma_emul_xfer_desc \
dma_emul_xfer_desc_##_inst[DMA_EMUL_INST_NUM_CHANNELS(_inst)]; \
\
static struct dma_block_config \
dma_emul_block_config_##_inst[DMA_EMUL_INST_NUM_CHANNELS(_inst) * \
DMA_EMUL_INST_NUM_REQUESTS(_inst)]; \
\
static const struct dma_emul_config dma_emul_config_##_inst = { \
.channel_mask = DMA_EMUL_INST_CHANNEL_MASK(_inst), \
.num_channels = DMA_EMUL_INST_NUM_CHANNELS(_inst), \
.num_requests = DMA_EMUL_INST_NUM_REQUESTS(_inst), \
.addr_align = DT_INST_PROP_OR(_inst, dma_buf_addr_alignment, 1), \
.size_align = DT_INST_PROP_OR(_inst, dma_buf_size_alignment, 1), \
.copy_align = DT_INST_PROP_OR(_inst, dma_copy_alignment, 1), \
.work_q_stack = (k_thread_stack_t *)&work_q_stack_##_inst, \
.work_q_stack_size = K_THREAD_STACK_SIZEOF(work_q_stack_##_inst), \
.work_q_priority = DT_INST_PROP_OR(_inst, priority, 0), \
.xfer = dma_emul_xfer_desc_##_inst, \
.block = dma_emul_block_config_##_inst, \
}; \
\
static ATOMIC_DEFINE(dma_emul_channels_atomic_##_inst, \
DT_INST_PROP_OR(_inst, dma_channels, 0)); \
\
static struct dma_emul_data dma_emul_data_##_inst = { \
.channels_atomic = dma_emul_channels_atomic_##_inst, \
}; \
\
PM_DEVICE_DT_INST_DEFINE(_inst, dma_emul_pm_device_pm_action); \
\
DEVICE_DT_INST_DEFINE(_inst, dma_emul_init, PM_DEVICE_DT_INST_GET(_inst), \
&dma_emul_data_##_inst, &dma_emul_config_##_inst, POST_KERNEL, \
CONFIG_DMA_INIT_PRIORITY, &dma_emul_driver_api);
DT_INST_FOREACH_STATUS_OKAY(DEFINE_DMA_EMUL)