The remoteproc driver core 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@xxxxxx> Cc: Linus Walleij <linus.walleij@xxxxxxxxxx> Signed-off-by: Suman Anna <s-anna@xxxxxx> --- v3: - no changes w.r.t v2 drivers/remoteproc/da8xx_remoteproc.c | 1 + drivers/remoteproc/omap_remoteproc.c | 5 +++++ drivers/remoteproc/remoteproc_core.c | 15 ++------------- drivers/remoteproc/ste_modem_rproc.c | 1 + include/linux/remoteproc.h | 2 ++ 5 files changed, 11 insertions(+), 13 deletions(-) diff --git a/drivers/remoteproc/da8xx_remoteproc.c b/drivers/remoteproc/da8xx_remoteproc.c index 89fd057e5f1d..f8d6a0661c14 100644 --- a/drivers/remoteproc/da8xx_remoteproc.c +++ b/drivers/remoteproc/da8xx_remoteproc.c @@ -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); diff --git a/drivers/remoteproc/omap_remoteproc.c b/drivers/remoteproc/omap_remoteproc.c index e85f30370760..4be005b272a7 100644 --- a/drivers/remoteproc/omap_remoteproc.c +++ b/drivers/remoteproc/omap_remoteproc.c @@ -202,6 +202,11 @@ static int omap_rproc_probe(struct platform_device *pdev) oproc = rproc->priv; oproc->rproc = rproc; + /* + * All existing OMAP IPU and DSP processors do have an MMU, and + * are expected to use MMU, so this statement suffices. + */ + rproc->has_iommu = true; platform_set_drvdata(pdev, rproc); diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c index 3cd85a638afa..11cdb119e4f3 100644 --- a/drivers/remoteproc/remoteproc_core.c +++ b/drivers/remoteproc/remoteproc_core.c @@ -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; } 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 */ diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h index 9e7e745dac55..78b8a9b9d40a 100644 --- a/include/linux/remoteproc.h +++ b/include/linux/remoteproc.h @@ -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 */ -- 2.2.1 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html