Jarkko Nikula 4afd728769 i3c: mipi-i3c-hci: Add DMA bounce buffer for private transfers ... Implement a local bounce buffer for private I3C SDR and I2C transfers when using DMA and the buffer attached to the transfer is not DMA safe. Otherwise the DMA transfer will fail and with following warning: [ 11.411059] i3c mipi-i3c-hci.0: rejecting DMA map of vmalloc memory [ 11.417313] WARNING: CPU: 3 PID: 357 at include/linux/dma-mapping.h:332 hci_dma_queue_xfer+0x2e2/0x300 [mipi_i3c_hci] Strictly speaking private I3C SDR transfers are expected to pass a DMA-able buffer. However I fear this requirement may easily be slipped or go unnoticed when I3C interface support is added into a existing device driver that use regmap API to read/write stack variables. For example this is the case with the commit 2660b0080b ("iio: imu: st_lsm6dsx: add i3c basic support for LSM6DSO and LSM6DSR"). Buffer of an I2C message is not required to be DMA safe and the I2C core provides i2c_(get|put)_dma_safe_msg_buf() helpers for the host controllers that do DMA and that is also recommendation for the i2c_xfers() callback from the I3C core. However due to above I3C private transfers reason I decided to implement a bounce buffer for them and reuse the same code for the I2C transfers too. Since this driver is currently the only I3C host controller driver that can do DMA the implementation is done here and not in I3C core. Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Link: https://lore.kernel.org/r/20231109133708.653950-5-jarkko.nikula@linux.intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>		2023-11-16 23:36:44 +01:00
..
master	i3c: mipi-i3c-hci: Add DMA bounce buffer for private transfers	2023-11-16 23:36:44 +01:00
device.c	driver core: make struct device_type.uevent() take a const *	2023-01-27 13:45:36 +01:00
internals.h	i3c: export SETDASA method	2022-12-11 21:25:58 +01:00
Kconfig
Makefile
master.c	I3C for 6.7	2023-11-04 16:25:36 -10:00