From b148d5fb2ef7bd1441e95402effe22b7b34f9a73 Mon Sep 17 00:00:00 2001 From: Suman Anna Date: Fri, 28 Feb 2014 14:42:37 -0600 Subject: iommu/omap: Enable bus-error back on supported iommus The remoteproc MMUs in OMAP4+ SoCs have some additional debug registers that can give out the PC value in addition to the MMU fault address. The PC value can be extracted properly only on the DSP cores, and is not available on the ARM processors within the IPU sub-systems. Instead, the MMUs have been enhanced to throw a bus-error response back to the IPU processors. This functionality is programmable through the MMU_GP_REG register. The cores are simply stalled if the MMU_GP_REG.BUS_ERR_BACK_EN bit is not set. When set, a bus-error exception is raised allowing the processor to handle it as a bus fault and provide additional debug information. This feature is turned on by default by the driver on iommus supporting it. Signed-off-by: Subramaniam Chanderashekarapuram Signed-off-by: Suman Anna Signed-off-by: Joerg Roedel --- drivers/iommu/omap-iommu.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/iommu/omap-iommu.c') diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c index eb73ef2b6fa9..28bc63143279 100644 --- a/drivers/iommu/omap-iommu.c +++ b/drivers/iommu/omap-iommu.c @@ -961,6 +961,8 @@ static int omap_iommu_probe(struct platform_device *pdev) */ obj->da_start = 0; obj->da_end = 0xfffff000; + if (of_find_property(of, "ti,iommu-bus-err-back", NULL)) + obj->has_bus_err_back = MMU_GP_REG_BUS_ERR_BACK_EN; } else { obj->nr_tlb_entries = pdata->nr_tlb_entries; obj->name = pdata->name; -- cgit v1.2.1