remoteproc: add IOMMU hardware capability flag

The remoteproc framework currently relies on iommu_present() on
the bus the device is on, to perform MMU management. However, this
logic doesn't scale for multi-arch, especially for processors that
do not have an IOMMU. Replace this logic instead by using a h/w
capability flag for the presence of IOMMU in the rproc structure.

This issue is seen on OMAP platforms when trying to add a remoteproc
driver for a small Cortex M3 called the WkupM3 used for suspend /
resume management on TI AM335/AM437x SoCs. This processor does not
have an MMU. Same is the case with another processor subsystem
PRU-ICSS on AM335/AM437x. All these are platform devices, and the
current iommu_present check will not scale for the same kernel image
to support OMAP4/OMAP5 and AM335/AM437x.

The existing platform implementation drivers - OMAP remoteproc, STE
Modem remoteproc and DA8xx remoteproc, are updated as well to properly
configure the newly added rproc field.

Cc: Robert Tivy <rtivy@ti.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Suman Anna <s-anna@ti.com>
[small change in the commit title and in a single comment]
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/remoteproc/ste_modem_rproc.c b/drivers/remoteproc/ste_modem_rproc.c
index 16b7b7bd805b..dd193f35a1ff 100644
--- a/drivers/remoteproc/ste_modem_rproc.c
+++ b/drivers/remoteproc/ste_modem_rproc.c
@@ -289,6 +289,7 @@ static int sproc_probe(struct platform_device *pdev)
         sproc = rproc->priv;
         sproc->mdev = mdev;
         sproc->rproc = rproc;
+        rproc->has_iommu = false;
         mdev->drv_data = sproc;
 
         /* Provide callback functions to modem device */