#include <linux/idr.h>
#include <linux/platform_data/x86/apple.h>
#include <linux/ptp_clock_kernel.h>
+#include <linux/percpu.h>
#define CREATE_TRACE_POINTS
#include <trace/events/spi.h>
spi_controller_put(spi->controller);
kfree(spi->driver_override);
+ free_percpu(spi->pcpu_statistics);
kfree(spi);
}
}
static DEVICE_ATTR_RW(driver_override);
+static struct spi_statistics *spi_alloc_pcpu_stats(struct device *dev)
+{
+ struct spi_statistics __percpu *pcpu_stats;
+
+ if (dev)
+ pcpu_stats = devm_alloc_percpu(dev, struct spi_statistics);
+ else
+ pcpu_stats = alloc_percpu_gfp(struct spi_statistics, GFP_KERNEL);
+
+ if (pcpu_stats) {
+ int cpu;
+
+ for_each_possible_cpu(cpu) {
+ struct spi_statistics *stat;
+
+ stat = per_cpu_ptr(pcpu_stats, cpu);
+ u64_stats_init(&stat->syncp);
+ }
+ }
+ return pcpu_stats;
+}
+
+#define spi_pcpu_stats_totalize(ret, in, field) \
+do { \
+ int i; \
+ ret = 0; \
+ for_each_possible_cpu(i) { \
+ const struct spi_statistics *pcpu_stats; \
+ u64 inc; \
+ unsigned int start; \
+ pcpu_stats = per_cpu_ptr(in, i); \
+ do { \
+ start = u64_stats_fetch_begin_irq( \
+ &pcpu_stats->syncp); \
+ inc = u64_stats_read(&pcpu_stats->field); \
+ } while (u64_stats_fetch_retry_irq( \
+ &pcpu_stats->syncp, start)); \
+ ret += inc; \
+ } \
+} while (0)
+
#define SPI_STATISTICS_ATTRS(field, file) \
static ssize_t spi_controller_##field##_show(struct device *dev, \
struct device_attribute *attr, \
{ \
struct spi_controller *ctlr = container_of(dev, \
struct spi_controller, dev); \
- return spi_statistics_##field##_show(&ctlr->statistics, buf); \
+ return spi_statistics_##field##_show(ctlr->pcpu_statistics, buf); \
} \
static struct device_attribute dev_attr_spi_controller_##field = { \
.attr = { .name = file, .mode = 0444 }, \
char *buf) \
{ \
struct spi_device *spi = to_spi_device(dev); \
- return spi_statistics_##field##_show(&spi->statistics, buf); \
+ return spi_statistics_##field##_show(spi->pcpu_statistics, buf); \
} \
static struct device_attribute dev_attr_spi_device_##field = { \
.attr = { .name = file, .mode = 0444 }, \
.show = spi_device_##field##_show, \
}
-#define SPI_STATISTICS_SHOW_NAME(name, file, field, format_string) \
+#define SPI_STATISTICS_SHOW_NAME(name, file, field) \
static ssize_t spi_statistics_##name##_show(struct spi_statistics *stat, \
char *buf) \
{ \
- unsigned long flags; \
ssize_t len; \
- spin_lock_irqsave(&stat->lock, flags); \
- len = sysfs_emit(buf, format_string "\n", stat->field); \
- spin_unlock_irqrestore(&stat->lock, flags); \
+ u64 val; \
+ spi_pcpu_stats_totalize(val, stat, field); \
+ len = sysfs_emit(buf, "%llu\n", val); \
return len; \
} \
SPI_STATISTICS_ATTRS(name, file)
-#define SPI_STATISTICS_SHOW(field, format_string) \
+#define SPI_STATISTICS_SHOW(field) \
SPI_STATISTICS_SHOW_NAME(field, __stringify(field), \
- field, format_string)
+ field)
-SPI_STATISTICS_SHOW(messages, "%lu");
-SPI_STATISTICS_SHOW(transfers, "%lu");
-SPI_STATISTICS_SHOW(errors, "%lu");
-SPI_STATISTICS_SHOW(timedout, "%lu");
+SPI_STATISTICS_SHOW(messages);
+SPI_STATISTICS_SHOW(transfers);
+SPI_STATISTICS_SHOW(errors);
+SPI_STATISTICS_SHOW(timedout);
-SPI_STATISTICS_SHOW(spi_sync, "%lu");
-SPI_STATISTICS_SHOW(spi_sync_immediate, "%lu");
-SPI_STATISTICS_SHOW(spi_async, "%lu");
+SPI_STATISTICS_SHOW(spi_sync);
+SPI_STATISTICS_SHOW(spi_sync_immediate);
+SPI_STATISTICS_SHOW(spi_async);
-SPI_STATISTICS_SHOW(bytes, "%llu");
-SPI_STATISTICS_SHOW(bytes_rx, "%llu");
-SPI_STATISTICS_SHOW(bytes_tx, "%llu");
+SPI_STATISTICS_SHOW(bytes);
+SPI_STATISTICS_SHOW(bytes_rx);
+SPI_STATISTICS_SHOW(bytes_tx);
#define SPI_STATISTICS_TRANSFER_BYTES_HISTO(index, number) \
SPI_STATISTICS_SHOW_NAME(transfer_bytes_histo##index, \
"transfer_bytes_histo_" number, \
- transfer_bytes_histo[index], "%lu")
+ transfer_bytes_histo[index])
SPI_STATISTICS_TRANSFER_BYTES_HISTO(0, "0-1");
SPI_STATISTICS_TRANSFER_BYTES_HISTO(1, "2-3");
SPI_STATISTICS_TRANSFER_BYTES_HISTO(2, "4-7");
SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535");
SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+");
-SPI_STATISTICS_SHOW(transfers_split_maxsize, "%lu");
+SPI_STATISTICS_SHOW(transfers_split_maxsize);
static struct attribute *spi_dev_attrs[] = {
&dev_attr_modalias.attr,
NULL,
};
-static void spi_statistics_add_transfer_stats(struct spi_statistics *stats,
+static void spi_statistics_add_transfer_stats(struct spi_statistics *pcpu_stats,
struct spi_transfer *xfer,
struct spi_controller *ctlr)
{
- unsigned long flags;
int l2len = min(fls(xfer->len), SPI_STATISTICS_HISTO_SIZE) - 1;
+ struct spi_statistics *stats;
if (l2len < 0)
l2len = 0;
- spin_lock_irqsave(&stats->lock, flags);
+ get_cpu();
+ stats = this_cpu_ptr(pcpu_stats);
+ u64_stats_update_begin(&stats->syncp);
- stats->transfers++;
- stats->transfer_bytes_histo[l2len]++;
+ u64_stats_inc(&stats->transfers);
+ u64_stats_inc(&stats->transfer_bytes_histo[l2len]);
- stats->bytes += xfer->len;
+ u64_stats_add(&stats->bytes, xfer->len);
if ((xfer->tx_buf) &&
(xfer->tx_buf != ctlr->dummy_tx))
- stats->bytes_tx += xfer->len;
+ u64_stats_add(&stats->bytes_tx, xfer->len);
if ((xfer->rx_buf) &&
(xfer->rx_buf != ctlr->dummy_rx))
- stats->bytes_rx += xfer->len;
+ u64_stats_add(&stats->bytes_rx, xfer->len);
- spin_unlock_irqrestore(&stats->lock, flags);
+ u64_stats_update_end(&stats->syncp);
+ put_cpu();
}
/*
return NULL;
}
+ spi->pcpu_statistics = spi_alloc_pcpu_stats(NULL);
+ if (!spi->pcpu_statistics) {
+ kfree(spi);
+ spi_controller_put(ctlr);
+ return NULL;
+ }
+
spi->master = spi->controller = ctlr;
spi->dev.parent = &ctlr->dev;
spi->dev.bus = &spi_bus_type;
spi->dev.release = spidev_release;
spi->mode = ctlr->buswidth_override_bits;
- spin_lock_init(&spi->statistics.lock);
-
device_initialize(&spi->dev);
return spi;
}
struct spi_message *msg,
struct spi_transfer *xfer)
{
- struct spi_statistics *statm = &ctlr->statistics;
- struct spi_statistics *stats = &msg->spi->statistics;
+ struct spi_statistics *statm = ctlr->pcpu_statistics;
+ struct spi_statistics *stats = msg->spi->pcpu_statistics;
u32 speed_hz = xfer->speed_hz;
unsigned long long ms;
/* Nothing to do here */
break;
case SPI_DELAY_UNIT_SCK:
- /* clock cycles need to be obtained from spi_transfer */
+ /* Clock cycles need to be obtained from spi_transfer */
if (!xfer)
return -EINVAL;
/*
u32 unit = xfer->cs_change_delay.unit;
int ret;
- /* return early on "fast" mode - for everything but USECS */
+ /* Return early on "fast" mode - for everything but USECS */
if (!delay) {
if (unit == SPI_DELAY_UNIT_USECS)
_spi_transfer_delay_ns(default_delay_ns);
struct spi_transfer *xfer;
bool keep_cs = false;
int ret = 0;
- struct spi_statistics *statm = &ctlr->statistics;
- struct spi_statistics *stats = &msg->spi->statistics;
+ struct spi_statistics *statm = ctlr->pcpu_statistics;
+ struct spi_statistics *stats = msg->spi->pcpu_statistics;
spi_set_cs(msg->spi, true, false);
}
}
+static int __spi_pump_transfer_message(struct spi_controller *ctlr,
+ struct spi_message *msg, bool was_busy)
+{
+ struct spi_transfer *xfer;
+ int ret;
+
+ if (!was_busy && ctlr->auto_runtime_pm) {
+ ret = pm_runtime_get_sync(ctlr->dev.parent);
+ if (ret < 0) {
+ pm_runtime_put_noidle(ctlr->dev.parent);
+ dev_err(&ctlr->dev, "Failed to power device: %d\n",
+ ret);
+ return ret;
+ }
+ }
+
+ if (!was_busy)
+ trace_spi_controller_busy(ctlr);
+
+ if (!was_busy && ctlr->prepare_transfer_hardware) {
+ ret = ctlr->prepare_transfer_hardware(ctlr);
+ if (ret) {
+ dev_err(&ctlr->dev,
+ "failed to prepare transfer hardware: %d\n",
+ ret);
+
+ if (ctlr->auto_runtime_pm)
+ pm_runtime_put(ctlr->dev.parent);
+
+ msg->status = ret;
+ spi_finalize_current_message(ctlr);
+
+ return ret;
+ }
+ }
+
+ trace_spi_message_start(msg);
+
+ if (ctlr->prepare_message) {
+ ret = ctlr->prepare_message(ctlr, msg);
+ if (ret) {
+ dev_err(&ctlr->dev, "failed to prepare message: %d\n",
+ ret);
+ msg->status = ret;
+ spi_finalize_current_message(ctlr);
+ return ret;
+ }
+ msg->prepared = true;
+ }
+
+ ret = spi_map_msg(ctlr, msg);
+ if (ret) {
+ msg->status = ret;
+ spi_finalize_current_message(ctlr);
+ return ret;
+ }
+
+ if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) {
+ list_for_each_entry(xfer, &msg->transfers, transfer_list) {
+ xfer->ptp_sts_word_pre = 0;
+ ptp_read_system_prets(xfer->ptp_sts);
+ }
+ }
+
+ /*
+ * Drivers implementation of transfer_one_message() must arrange for
+ * spi_finalize_current_message() to get called. Most drivers will do
+ * this in the calling context, but some don't. For those cases, a
+ * completion is used to guarantee that this function does not return
+ * until spi_finalize_current_message() is done accessing
+ * ctlr->cur_msg.
+ * Use of the following two flags enable to opportunistically skip the
+ * use of the completion since its use involves expensive spin locks.
+ * In case of a race with the context that calls
+ * spi_finalize_current_message() the completion will always be used,
+ * due to strict ordering of these flags using barriers.
+ */
+ WRITE_ONCE(ctlr->cur_msg_incomplete, true);
+ WRITE_ONCE(ctlr->cur_msg_need_completion, false);
+ reinit_completion(&ctlr->cur_msg_completion);
+ smp_wmb(); /* Make these available to spi_finalize_current_message() */
+
+ ret = ctlr->transfer_one_message(ctlr, msg);
+ if (ret) {
+ dev_err(&ctlr->dev,
+ "failed to transfer one message from queue\n");
+ return ret;
+ }
+
+ WRITE_ONCE(ctlr->cur_msg_need_completion, true);
+ smp_mb(); /* See spi_finalize_current_message()... */
+ if (READ_ONCE(ctlr->cur_msg_incomplete))
+ wait_for_completion(&ctlr->cur_msg_completion);
+
+ return 0;
+}
+
/**
* __spi_pump_messages - function which processes spi message queue
* @ctlr: controller to process queue for
*/
static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread)
{
- struct spi_transfer *xfer;
struct spi_message *msg;
bool was_busy = false;
unsigned long flags;
int ret;
+ /* Take the IO mutex */
+ mutex_lock(&ctlr->io_mutex);
+
/* Lock queue */
spin_lock_irqsave(&ctlr->queue_lock, flags);
/* Make sure we are not already running a message */
- if (ctlr->cur_msg) {
- spin_unlock_irqrestore(&ctlr->queue_lock, flags);
- return;
- }
-
- /* If another context is idling the device then defer */
- if (ctlr->idling) {
- kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
- spin_unlock_irqrestore(&ctlr->queue_lock, flags);
- return;
- }
+ if (ctlr->cur_msg)
+ goto out_unlock;
/* Check if the queue is idle */
if (list_empty(&ctlr->queue) || !ctlr->running) {
- if (!ctlr->busy) {
- spin_unlock_irqrestore(&ctlr->queue_lock, flags);
- return;
- }
+ if (!ctlr->busy)
+ goto out_unlock;
/* Defer any non-atomic teardown to the thread */
if (!in_kthread) {
!ctlr->unprepare_transfer_hardware) {
spi_idle_runtime_pm(ctlr);
ctlr->busy = false;
+ ctlr->queue_empty = true;
trace_spi_controller_idle(ctlr);
} else {
kthread_queue_work(ctlr->kworker,
&ctlr->pump_messages);
}
- spin_unlock_irqrestore(&ctlr->queue_lock, flags);
- return;
+ goto out_unlock;
}
ctlr->busy = false;
- ctlr->idling = true;
spin_unlock_irqrestore(&ctlr->queue_lock, flags);
kfree(ctlr->dummy_rx);
trace_spi_controller_idle(ctlr);
spin_lock_irqsave(&ctlr->queue_lock, flags);
- ctlr->idling = false;
- spin_unlock_irqrestore(&ctlr->queue_lock, flags);
- return;
+ ctlr->queue_empty = true;
+ goto out_unlock;
}
/* Extract head of queue */
ctlr->busy = true;
spin_unlock_irqrestore(&ctlr->queue_lock, flags);
- mutex_lock(&ctlr->io_mutex);
-
- if (!was_busy && ctlr->auto_runtime_pm) {
- ret = pm_runtime_resume_and_get(ctlr->dev.parent);
- if (ret < 0) {
- dev_err(&ctlr->dev, "Failed to power device: %d\n",
- ret);
- mutex_unlock(&ctlr->io_mutex);
- return;
- }
- }
-
- if (!was_busy)
- trace_spi_controller_busy(ctlr);
-
- if (!was_busy && ctlr->prepare_transfer_hardware) {
- ret = ctlr->prepare_transfer_hardware(ctlr);
- if (ret) {
- dev_err(&ctlr->dev,
- "failed to prepare transfer hardware: %d\n",
- ret);
-
- if (ctlr->auto_runtime_pm)
- pm_runtime_put(ctlr->dev.parent);
-
- msg->status = ret;
- spi_finalize_current_message(ctlr);
-
- mutex_unlock(&ctlr->io_mutex);
- return;
- }
- }
-
- trace_spi_message_start(msg);
-
- if (ctlr->prepare_message) {
- ret = ctlr->prepare_message(ctlr, msg);
- if (ret) {
- dev_err(&ctlr->dev, "failed to prepare message: %d\n",
- ret);
- msg->status = ret;
- spi_finalize_current_message(ctlr);
- goto out;
- }
- ctlr->cur_msg_prepared = true;
- }
-
- ret = spi_map_msg(ctlr, msg);
- if (ret) {
- msg->status = ret;
- spi_finalize_current_message(ctlr);
- goto out;
- }
-
- if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) {
- list_for_each_entry(xfer, &msg->transfers, transfer_list) {
- xfer->ptp_sts_word_pre = 0;
- ptp_read_system_prets(xfer->ptp_sts);
- }
- }
+ ret = __spi_pump_transfer_message(ctlr, msg, was_busy);
+ if (!ret)
+ kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
- ret = ctlr->transfer_one_message(ctlr, msg);
- if (ret) {
- dev_err(&ctlr->dev,
- "failed to transfer one message from queue: %d\n",
- ret);
- goto out;
- }
+ ctlr->cur_msg = NULL;
+ ctlr->fallback = false;
-out:
mutex_unlock(&ctlr->io_mutex);
/* Prod the scheduler in case transfer_one() was busy waiting */
if (!ret)
cond_resched();
+ return;
+
+out_unlock:
+ spin_unlock_irqrestore(&ctlr->queue_lock, flags);
+ mutex_unlock(&ctlr->io_mutex);
}
/**
{
ctlr->running = false;
ctlr->busy = false;
+ ctlr->queue_empty = true;
ctlr->kworker = kthread_create_worker(0, dev_name(&ctlr->dev));
if (IS_ERR(ctlr->kworker)) {
struct spi_message *next;
unsigned long flags;
- /* get a pointer to the next message, if any */
+ /* Get a pointer to the next message, if any */
spin_lock_irqsave(&ctlr->queue_lock, flags);
next = list_first_entry_or_null(&ctlr->queue, struct spi_message,
queue);
{
struct spi_transfer *xfer;
struct spi_message *mesg;
- unsigned long flags;
int ret;
- spin_lock_irqsave(&ctlr->queue_lock, flags);
mesg = ctlr->cur_msg;
- spin_unlock_irqrestore(&ctlr->queue_lock, flags);
if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) {
list_for_each_entry(xfer, &mesg->transfers, transfer_list) {
*/
spi_res_release(ctlr, mesg);
- if (ctlr->cur_msg_prepared && ctlr->unprepare_message) {
+ if (mesg->prepared && ctlr->unprepare_message) {
ret = ctlr->unprepare_message(ctlr, mesg);
if (ret) {
dev_err(&ctlr->dev, "failed to unprepare message: %d\n",
}
}
- spin_lock_irqsave(&ctlr->queue_lock, flags);
- ctlr->cur_msg = NULL;
- ctlr->cur_msg_prepared = false;
- ctlr->fallback = false;
- kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
- spin_unlock_irqrestore(&ctlr->queue_lock, flags);
+ mesg->prepared = false;
+
+ WRITE_ONCE(ctlr->cur_msg_incomplete, false);
+ smp_mb(); /* See __spi_pump_transfer_message()... */
+ if (READ_ONCE(ctlr->cur_msg_need_completion))
+ complete(&ctlr->cur_msg_completion);
trace_spi_message_done(mesg);
msg->status = -EINPROGRESS;
list_add_tail(&msg->queue, &ctlr->queue);
+ ctlr->queue_empty = false;
if (!ctlr->busy && need_pump)
kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
if (lookup->index != -1 && lookup->n++ != lookup->index)
return 1;
- if (lookup->index == -1 && !ctlr)
- return -ENODEV;
-
status = acpi_get_handle(NULL,
sb->resource_source.string_ptr,
&parent_handle);
ctlr = acpi_spi_find_controller_by_adev(adev);
if (!ctlr)
- return -ENODEV;
+ return -EPROBE_DEFER;
lookup->ctlr = ctlr;
}
acpi_dev_free_resource_list(&resource_list);
if (ret < 0)
- /* found SPI in _CRS but it points to another controller */
- return ERR_PTR(-ENODEV);
+ /* Found SPI in _CRS but it points to another controller */
+ return ERR_PTR(ret);
if (!lookup.max_speed_hz &&
ACPI_SUCCESS(acpi_get_parent(adev->handle, &parent_handle)) &&
return status;
if (ctlr->bus_num >= 0) {
- /* devices with a fixed bus num must check-in with the num */
+ /* Devices with a fixed bus num must check-in with the num */
mutex_lock(&board_lock);
id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num,
ctlr->bus_num + 1, GFP_KERNEL);
return id == -ENOSPC ? -EBUSY : id;
ctlr->bus_num = id;
} else if (ctlr->dev.of_node) {
- /* allocate dynamic bus number using Linux idr */
+ /* Allocate dynamic bus number using Linux idr */
id = of_alias_get_id(ctlr->dev.of_node, "spi");
if (id >= 0) {
ctlr->bus_num = id;
}
ctlr->bus_lock_flag = 0;
init_completion(&ctlr->xfer_completion);
+ init_completion(&ctlr->cur_msg_completion);
if (!ctlr->max_dma_len)
ctlr->max_dma_len = INT_MAX;
goto free_bus_id;
}
- /* setting last_cs to -1 means no chip selected */
+ /* Setting last_cs to -1 means no chip selected */
ctlr->last_cs = -1;
status = device_add(&ctlr->dev);
goto free_bus_id;
}
}
- /* add statistics */
- spin_lock_init(&ctlr->statistics.lock);
+ /* Add statistics */
+ ctlr->pcpu_statistics = spi_alloc_pcpu_stats(dev);
+ if (!ctlr->pcpu_statistics) {
+ dev_err(dev, "Error allocating per-cpu statistics\n");
+ status = -ENOMEM;
+ goto destroy_queue;
+ }
mutex_lock(&board_lock);
list_add_tail(&ctlr->list, &spi_controller_list);
acpi_register_spi_devices(ctlr);
return status;
+destroy_queue:
+ spi_destroy_queue(ctlr);
free_bus_id:
mutex_lock(&board_lock);
idr_remove(&spi_master_idr, ctlr->bus_num);
}
EXPORT_SYMBOL_GPL(spi_register_controller);
-static void devm_spi_unregister(void *ctlr)
+static void devm_spi_unregister(struct device *dev, void *res)
{
- spi_unregister_controller(ctlr);
+ spi_unregister_controller(*(struct spi_controller **)res);
}
/**
int devm_spi_register_controller(struct device *dev,
struct spi_controller *ctlr)
{
+ struct spi_controller **ptr;
int ret;
+ ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL);
+ if (!ptr)
+ return -ENOMEM;
+
ret = spi_register_controller(ctlr);
- if (ret)
- return ret;
+ if (!ret) {
+ *ptr = ctlr;
+ devres_add(dev, ptr);
+ } else {
+ devres_free(ptr);
+ }
- return devm_add_action_or_reset(dev, devm_spi_unregister, ctlr);
+ return ret;
}
EXPORT_SYMBOL_GPL(devm_spi_register_controller);
device_del(&ctlr->dev);
- /* free bus id */
+ /* Free bus id */
mutex_lock(&board_lock);
if (found == ctlr)
idr_remove(&spi_master_idr, id);
struct spi_replaced_transfers *rxfer = res;
size_t i;
- /* call extra callback if requested */
+ /* Call extra callback if requested */
if (rxfer->release)
rxfer->release(ctlr, msg, res);
- /* insert replaced transfers back into the message */
+ /* Insert replaced transfers back into the message */
list_splice(&rxfer->replaced_transfers, rxfer->replaced_after);
- /* remove the formerly inserted entries */
+ /* Remove the formerly inserted entries */
for (i = 0; i < rxfer->inserted; i++)
list_del(&rxfer->inserted_transfers[i].transfer_list);
}
struct spi_transfer *xfer;
size_t i;
- /* allocate the structure using spi_res */
+ /* Allocate the structure using spi_res */
rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release,
struct_size(rxfer, inserted_transfers, insert)
+ extradatasize,
if (!rxfer)
return ERR_PTR(-ENOMEM);
- /* the release code to invoke before running the generic release */
+ /* The release code to invoke before running the generic release */
rxfer->release = release;
- /* assign extradata */
+ /* Assign extradata */
if (extradatasize)
rxfer->extradata =
&rxfer->inserted_transfers[insert];
- /* init the replaced_transfers list */
+ /* Init the replaced_transfers list */
INIT_LIST_HEAD(&rxfer->replaced_transfers);
/*
*/
rxfer->replaced_after = xfer_first->transfer_list.prev;
- /* remove the requested number of transfers */
+ /* Remove the requested number of transfers */
for (i = 0; i < remove; i++) {
/*
* If the entry after replaced_after it is msg->transfers
if (rxfer->replaced_after->next == &msg->transfers) {
dev_err(&msg->spi->dev,
"requested to remove more spi_transfers than are available\n");
- /* insert replaced transfers back into the message */
+ /* Insert replaced transfers back into the message */
list_splice(&rxfer->replaced_transfers,
rxfer->replaced_after);
- /* free the spi_replace_transfer structure */
+ /* Free the spi_replace_transfer structure... */
spi_res_free(rxfer);
- /* and return with an error */
+ /* ...and return with an error */
return ERR_PTR(-EINVAL);
}
* based on the first transfer to get removed.
*/
for (i = 0; i < insert; i++) {
- /* we need to run in reverse order */
+ /* We need to run in reverse order */
xfer = &rxfer->inserted_transfers[insert - 1 - i];
- /* copy all spi_transfer data */
+ /* Copy all spi_transfer data */
memcpy(xfer, xfer_first, sizeof(*xfer));
- /* add to list */
+ /* Add to list */
list_add(&xfer->transfer_list, rxfer->replaced_after);
- /* clear cs_change and delay for all but the last */
+ /* Clear cs_change and delay for all but the last */
if (i) {
xfer->cs_change = false;
xfer->delay.value = 0;
}
}
- /* set up inserted */
+ /* Set up inserted... */
rxfer->inserted = insert;
- /* and register it with spi_res/spi_message */
+ /* ...and register it with spi_res/spi_message */
spi_res_add(msg, rxfer);
return rxfer;
size_t offset;
size_t count, i;
- /* calculate how many we have to replace */
+ /* Calculate how many we have to replace */
count = DIV_ROUND_UP(xfer->len, maxsize);
- /* create replacement */
+ /* Create replacement */
srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp);
if (IS_ERR(srt))
return PTR_ERR(srt);
*/
xfers[0].len = min_t(size_t, maxsize, xfer[0].len);
- /* all the others need rx_buf/tx_buf also set */
+ /* All the others need rx_buf/tx_buf also set */
for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) {
- /* update rx_buf, tx_buf and dma */
+ /* Update rx_buf, tx_buf and dma */
if (xfers[i].rx_buf)
xfers[i].rx_buf += offset;
if (xfers[i].rx_dma)
if (xfers[i].tx_dma)
xfers[i].tx_dma += offset;
- /* update length */
+ /* Update length */
xfers[i].len = min(maxsize, xfers[i].len - offset);
}
*/
*xferp = &xfers[count - 1];
- /* increment statistics counters */
- SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics,
+ /* Increment statistics counters */
+ SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics,
transfers_split_maxsize);
- SPI_STATISTICS_INCREMENT_FIELD(&msg->spi->statistics,
+ SPI_STATISTICS_INCREMENT_FIELD(msg->spi->pcpu_statistics,
transfers_split_maxsize);
return 0;
return ret;
list_for_each_entry(xfer, &message->transfers, transfer_list) {
- /* don't change cs_change on the last entry in the list */
+ /* Don't change cs_change on the last entry in the list */
if (list_is_last(&xfer->transfer_list, &message->transfers))
break;
xfer->cs_change = 1;
!(spi->mode & SPI_TX_QUAD))
return -EINVAL;
}
- /* check transfer rx_nbits */
+ /* Check transfer rx_nbits */
if (xfer->rx_buf) {
if (spi->mode & SPI_NO_RX)
return -EINVAL;
message->spi = spi;
- SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_async);
- SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_async);
+ SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics, spi_async);
+ SPI_STATISTICS_INCREMENT_FIELD(spi->pcpu_statistics, spi_async);
trace_spi_message_submit(message);
}
+static void __spi_transfer_message_noqueue(struct spi_controller *ctlr, struct spi_message *msg)
+{
+ bool was_busy;
+ int ret;
+
+ mutex_lock(&ctlr->io_mutex);
+
+ was_busy = ctlr->busy;
+
+ ctlr->cur_msg = msg;
+ ret = __spi_pump_transfer_message(ctlr, msg, was_busy);
+ if (ret)
+ goto out;
+
+ ctlr->cur_msg = NULL;
+ ctlr->fallback = false;
+
+ if (!was_busy) {
+ kfree(ctlr->dummy_rx);
+ ctlr->dummy_rx = NULL;
+ kfree(ctlr->dummy_tx);
+ ctlr->dummy_tx = NULL;
+ if (ctlr->unprepare_transfer_hardware &&
+ ctlr->unprepare_transfer_hardware(ctlr))
+ dev_err(&ctlr->dev,
+ "failed to unprepare transfer hardware\n");
+ spi_idle_runtime_pm(ctlr);
+ }
+
+out:
+ mutex_unlock(&ctlr->io_mutex);
+}
+
/*-------------------------------------------------------------------------*/
/*
DECLARE_COMPLETION_ONSTACK(done);
int status;
struct spi_controller *ctlr = spi->controller;
- unsigned long flags;
status = __spi_validate(spi, message);
if (status != 0)
return status;
- message->complete = spi_complete;
- message->context = &done;
message->spi = spi;
- SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_sync);
- SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync);
+ SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics, spi_sync);
+ SPI_STATISTICS_INCREMENT_FIELD(spi->pcpu_statistics, spi_sync);
/*
- * If we're not using the legacy transfer method then we will
- * try to transfer in the calling context so special case.
- * This code would be less tricky if we could remove the
- * support for driver implemented message queues.
+ * Checking queue_empty here only guarantees async/sync message
+ * ordering when coming from the same context. It does not need to
+ * guard against reentrancy from a different context. The io_mutex
+ * will catch those cases.
*/
- if (ctlr->transfer == spi_queued_transfer) {
- spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
+ if (READ_ONCE(ctlr->queue_empty)) {
+ message->actual_length = 0;
+ message->status = -EINPROGRESS;
trace_spi_message_submit(message);
- status = __spi_queued_transfer(spi, message, false);
+ SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics, spi_sync_immediate);
+ SPI_STATISTICS_INCREMENT_FIELD(spi->pcpu_statistics, spi_sync_immediate);
- spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
- } else {
- status = spi_async_locked(spi, message);
+ __spi_transfer_message_noqueue(ctlr, message);
+
+ return message->status;
}
+ /*
+ * There are messages in the async queue that could have originated
+ * from the same context, so we need to preserve ordering.
+ * Therefor we send the message to the async queue and wait until they
+ * are completed.
+ */
+ message->complete = spi_complete;
+ message->context = &done;
+ status = spi_async_locked(spi, message);
if (status == 0) {
- /* Push out the messages in the calling context if we can */
- if (ctlr->transfer == spi_queued_transfer) {
- SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics,
- spi_sync_immediate);
- SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics,
- spi_sync_immediate);
- __spi_pump_messages(ctlr, false);
- }
-
wait_for_completion(&done);
status = message->status;
}
message->context = NULL;
+
return status;
}
ctlr->bus_lock_flag = 1;
spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
- /* mutex remains locked until spi_bus_unlock is called */
+ /* Mutex remains locked until spi_bus_unlock() is called */
return 0;
}
}
EXPORT_SYMBOL_GPL(spi_bus_unlock);
-/* portable code must never pass more than 32 bytes */
+/* Portable code must never pass more than 32 bytes */
#define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
static u8 *buf;
x[0].tx_buf = local_buf;
x[1].rx_buf = local_buf + n_tx;
- /* do the i/o */
+ /* Do the i/o */
status = spi_sync(spi, &message);
if (status == 0)
memcpy(rxbuf, x[1].rx_buf, n_rx);
/*-------------------------------------------------------------------------*/
#if IS_ENABLED(CONFIG_OF_DYNAMIC)
-/* must call put_device() when done with returned spi_device device */
+/* Must call put_device() when done with returned spi_device device */
static struct spi_device *of_find_spi_device_by_node(struct device_node *node)
{
struct device *dev = bus_find_device_by_of_node(&spi_bus_type, node);
return dev ? to_spi_device(dev) : NULL;
}
-/* the spi controllers are not using spi_bus, so we find it with another way */
+/* The spi controllers are not using spi_bus, so we find it with another way */
static struct spi_controller *of_find_spi_controller_by_node(struct device_node *node)
{
struct device *dev;
if (!dev)
return NULL;
- /* reference got in class_find_device */
+ /* Reference got in class_find_device */
return container_of(dev, struct spi_controller, dev);
}
case OF_RECONFIG_CHANGE_ADD:
ctlr = of_find_spi_controller_by_node(rd->dn->parent);
if (ctlr == NULL)
- return NOTIFY_OK; /* not for us */
+ return NOTIFY_OK; /* Not for us */
if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
put_device(&ctlr->dev);
break;
case OF_RECONFIG_CHANGE_REMOVE:
- /* already depopulated? */
+ /* Already depopulated? */
if (!of_node_check_flag(rd->dn, OF_POPULATED))
return NOTIFY_OK;
- /* find our device by node */
+ /* Find our device by node */
spi = of_find_spi_device_by_node(rd->dn);
if (spi == NULL)
- return NOTIFY_OK; /* no? not meant for us */
+ return NOTIFY_OK; /* No? not meant for us */
- /* unregister takes one ref away */
+ /* Unregister takes one ref away */
spi_unregister_device(spi);
- /* and put the reference of the find */
+ /* And put the reference of the find */
put_device(&spi->dev);
break;
}
git.samba.org / sfrench / cifs-2.6.git / blobdiff