omap: IOMMU: add support to callback during fault handling

Add support to register an isr for IOMMU fault situations and adapt it
to allow such (*isr)() to be used as fault callback. Drivers using IOMMU
module might want to be informed when errors happen in order to debug it
or react.

Signed-off-by: David Cohen <dacohen@gmail.com>
Acked-by: Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

1 files changed, 15 insertions, 2 deletions

diff --git a/arch/arm/mach-omap2/iommu2.c b/arch/arm/mach-omap2/iommu2.c
index 49a1e5e841ca..adb083e41acd 100644
--- a/arch/arm/mach-omap2/iommu2.c
+++ b/arch/arm/mach-omap2/iommu2.c
@@ -146,18 +146,31 @@ static void omap2_iommu_set_twl(struct iommu *obj, bool on)
 static u32 omap2_iommu_fault_isr(struct iommu *obj, u32 *ra)
 {
         u32 stat, da;
+        u32 errs = 0;
 
         stat = iommu_read_reg(obj, MMU_IRQSTATUS);
         stat &= MMU_IRQ_MASK;
-        if (!stat)
+        if (!stat) {
+                *ra = 0;
                 return 0;
+        }
 
         da = iommu_read_reg(obj, MMU_FAULT_AD);
         *ra = da;
 
+        if (stat & MMU_IRQ_TLBMISS)
+                errs |= OMAP_IOMMU_ERR_TLB_MISS;
+        if (stat & MMU_IRQ_TRANSLATIONFAULT)
+                errs |= OMAP_IOMMU_ERR_TRANS_FAULT;
+        if (stat & MMU_IRQ_EMUMISS)
+                errs |= OMAP_IOMMU_ERR_EMU_MISS;
+        if (stat & MMU_IRQ_TABLEWALKFAULT)
+                errs |= OMAP_IOMMU_ERR_TBLWALK_FAULT;
+        if (stat & MMU_IRQ_MULTIHITFAULT)
+                errs |= OMAP_IOMMU_ERR_MULTIHIT_FAULT;
         iommu_write_reg(obj, stat, MMU_IRQSTATUS);
 
-        return stat;
+        return errs;
 }
 
 static void omap2_tlb_read_cr(struct iommu *obj, struct cr_regs *cr)