dma: Drop syscalls

DMA syscalls as they were implemented were unsafe. Accepting a void* was
never acceptable as many things could not be verified about it.
Accepting a channel identifier meant that a user mode thread could
start/stop any DMA channel which in theory could be owned by any other
driver. This shouldn't be possible.

Signed-off-by: Tom Burdick <[email protected]>

Author: teburd

include/zephyr/drivers/dma.h

@@ -451,9 +451,7 @@ static inline int dma_reload(const struct device *dev, uint32_t channel,
  * @retval 0 if successful.
  * @retval Negative errno code if failure.
  */
-__syscall int dma_start(const struct device *dev, uint32_t channel);
-
-static inline int z_impl_dma_start(const struct device *dev, uint32_t channel)
+static inline int dma_start(const struct device *dev, uint32_t channel)
 {
 	const struct dma_driver_api *api =
 		(const struct dma_driver_api *)dev->api;
@@ -479,9 +477,7 @@ static inline int z_impl_dma_start(const struct device *dev, uint32_t channel)
  * @retval 0 if successful.
  * @retval Negative errno code if failure.
  */
-__syscall int dma_stop(const struct device *dev, uint32_t channel);
-
-static inline int z_impl_dma_stop(const struct device *dev, uint32_t channel)
+static inline int dma_stop(const struct device *dev, uint32_t channel)
 {
 	const struct dma_driver_api *api =
 		(const struct dma_driver_api *)dev->api;
@@ -506,9 +502,7 @@ static inline int z_impl_dma_stop(const struct device *dev, uint32_t channel)
  * @retval -EINVAL If invalid channel id or state.
  * @retval -errno Other negative errno code failure.
  */
-__syscall int dma_suspend(const struct device *dev, uint32_t channel);
-
-static inline int z_impl_dma_suspend(const struct device *dev, uint32_t channel)
+static inline int dma_suspend(const struct device *dev, uint32_t channel)
 {
 	const struct dma_driver_api *api = (const struct dma_driver_api *)dev->api;
 
@@ -534,9 +528,7 @@ static inline int z_impl_dma_suspend(const struct device *dev, uint32_t channel)
  * @retval -EINVAL If invalid channel id or state.
  * @retval -errno Other negative errno code failure.
  */
-__syscall int dma_resume(const struct device *dev, uint32_t channel);
-
-static inline int z_impl_dma_resume(const struct device *dev, uint32_t channel)
+static inline int dma_resume(const struct device *dev, uint32_t channel)
 {
 	const struct dma_driver_api *api = (const struct dma_driver_api *)dev->api;
 
@@ -562,11 +554,7 @@ static inline int z_impl_dma_resume(const struct device *dev, uint32_t channel)
  * @retval dma channel if successful.
  * @retval Negative errno code if failure.
  */
-__syscall int dma_request_channel(const struct device *dev,
-				  void *filter_param);
-
-static inline int z_impl_dma_request_channel(const struct device *dev,
-					     void *filter_param)
+static inline int dma_request_channel(const struct device *dev, void *filter_param)
 {
 	int i = 0;
 	int channel = -EINVAL;
@@ -607,11 +595,7 @@ static inline int z_impl_dma_request_channel(const struct device *dev,
  * @param channel  channel number
  *
  */
-__syscall void dma_release_channel(const struct device *dev,
-				   uint32_t channel);
-
-static inline void z_impl_dma_release_channel(const struct device *dev,
-					      uint32_t channel)
+static inline void dma_release_channel(const struct device *dev, uint32_t channel)
 {
 	const struct dma_driver_api *api =
 		(const struct dma_driver_api *)dev->api;
@@ -643,11 +627,7 @@ static inline void z_impl_dma_release_channel(const struct device *dev,
  * @retval Negative errno code if not support
  *
  */
-__syscall int dma_chan_filter(const struct device *dev,
-				   int channel, void *filter_param);
-
-static inline int z_impl_dma_chan_filter(const struct device *dev,
-					      int channel, void *filter_param)
+static inline int dma_chan_filter(const struct device *dev, int channel, void *filter_param)
 {
 	const struct dma_driver_api *api =
 		(const struct dma_driver_api *)dev->api;
@@ -812,6 +792,4 @@ static inline uint32_t dma_burst_index(uint32_t burst)
 }
 #endif
 
-#include <zephyr/syscalls/dma.h>
-
 #endif /* ZEPHYR_INCLUDE_DRIVERS_DMA_H_ */