Add new uio device for dynamic memory allocation
This device extends the uio_pdrv_genirq driver to provide limited
dynamic memory allocation for UIO devices. This allows UIO devices
to use CMA and IOMMU allocated memory regions. This driver is based
on the uio_pdrv_genirq driver and provides the same generic interrupt
handling capabilities. Like uio_prdv_genirq,
a fixed number of memory regions, defined in the platform device's
.resources field are exported to userpace. This driver adds the ability
to export additional regions whose number and size are known at boot time,
but whose memory is not allocated until the uio device file is opened for
the first time. When the device file is closed, the allocated memory block
is freed. Physical (DMA) addresses for the dynamic regions are provided to
the userspace via /sys/class/uio/uioX/maps/mapY/addr in the same way as
static addresses are when the uio device file is open, when no processes
are holding the device file open, the address returned to userspace is
DMA_ERROR_CODE.
Signed-off-by: Damian Hobson-Garcia <dhobsong@igel.co.jp>
Signed-off-by: "Hans J. Koch" <hjk@hansjkoch.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/uio/Kconfig b/drivers/uio/Kconfig
index 6f3ea9b..82e2b89 100644
--- a/drivers/uio/Kconfig
+++ b/drivers/uio/Kconfig
@@ -44,6 +44,22 @@
If you don't know what to do here, say N.
+config UIO_DMEM_GENIRQ
+ tristate "Userspace platform driver with generic irq and dynamic memory"
+ help
+ Platform driver for Userspace I/O devices, including generic
+ interrupt handling code. Shared interrupts are not supported.
+
+ Memory regions can be specified with the same platform device
+ resources as the UIO_PDRV drivers, but dynamic regions can also
+ be specified.
+ The number and size of these regions is static,
+ but the memory allocation is not performed until
+ the associated device file is opened. The
+ memory is freed once the uio device is closed.
+
+ If you don't know what to do here, say N.
+
config UIO_AEC
tristate "AEC video timestamp device"
depends on PCI