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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>
This commit is contained in:
Suman Anna 2015-01-09 15:21:58 -06:00 committed by Ohad Ben-Cohen
parent c517d838eb
commit 315491e5d6
5 changed files with 8 additions and 13 deletions
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1
drivers/remoteproc/da8xx_remoteproc.c
View File

@ -224,6 +224,7 @@ static int da8xx_rproc_probe(struct platform_device *pdev)
drproc = rproc->priv;
drproc->rproc = rproc;
rproc->has_iommu = false;
platform_set_drvdata(pdev, rproc);

2
drivers/remoteproc/omap_remoteproc.c
View File

@ -202,6 +202,8 @@ static int omap_rproc_probe(struct platform_device *pdev)
oproc = rproc->priv;
oproc->rproc = rproc;
/* All existing OMAP IPU and DSP processors have an MMU */
rproc->has_iommu = true;
platform_set_drvdata(pdev, rproc);

15
drivers/remoteproc/remoteproc_core.c
View File

@ -94,19 +94,8 @@ static int rproc_enable_iommu(struct rproc *rproc)
struct device *dev = rproc->dev.parent;
int ret;
/*
* We currently use iommu_present() to decide if an IOMMU
* setup is needed.
*
* This works for simple cases, but will easily fail with
* platforms that do have an IOMMU, but not for this specific
* rproc.
*
* This will be easily solved by introducing hw capabilities
* that will be set by the remoteproc driver.
*/
if (!iommu_present(dev->bus)) {
dev_dbg(dev, "iommu not found\n");
if (!rproc->has_iommu) {
dev_dbg(dev, "iommu not present\n");
return 0;
}

1
drivers/remoteproc/ste_modem_rproc.c
View File

@ -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 */

2
include/linux/remoteproc.h
View File

@ -404,6 +404,7 @@ enum rproc_crash_type {
* @table_ptr: pointer to the resource table in effect
* @cached_table: copy of the resource table
* @table_csum: checksum of the resource table
* @has_iommu: flag to indicate if remote processor is behind an MMU
*/
struct rproc {
struct klist_node node;
@ -435,6 +436,7 @@ struct rproc {
struct resource_table *table_ptr;
struct resource_table *cached_table;
u32 table_csum;
bool has_iommu;
};
/* we currently support only two vrings per rvdev */