omap iommu: add functionality to get TLB miss interrupt

In order to enable TLB miss interrupt, the TWL should be
disabled. This patch provides the functionality to get the
MMU fault interrupt for a TLB miss in the cases where the
users are working with the locked TLB entries and with TWL
disabled.
New interface is added to select twl and to enable TLB miss
interrupt.

Signed-off-by: Hari Kanigeri <h-kanigeri2@ti.com>
Signed-off-by: Ramesh Gupta <grgupta@ti.com>
Signed-off-by: Hiroshi Doyu <Hiroshi.DOYU@nokia.com>

1 files changed, 27 insertions, 5 deletions

diff --git a/arch/arm/mach-omap2/iommu2.c b/arch/arm/mach-omap2/iommu2.c
index ebbdae262f78..edf7cd4b6553 100644
--- a/arch/arm/mach-omap2/iommu2.c
+++ b/arch/arm/mach-omap2/iommu2.c
@@ -65,6 +65,26 @@
          ((pgsz) == MMU_CAM_PGSZ_64K) ? 0xffff0000 :    \
          ((pgsz) == MMU_CAM_PGSZ_4K)  ? 0xfffff000 : 0)
 
+
+static void __iommu_set_twl(struct iommu *obj, bool on)
+{
+        u32 l = iommu_read_reg(obj, MMU_CNTL);
+
+        if (on)
+                iommu_write_reg(obj, MMU_IRQ_TWL_MASK, MMU_IRQENABLE);
+        else
+                iommu_write_reg(obj, MMU_IRQ_TLB_MISS_MASK, MMU_IRQENABLE);
+
+        l &= ~MMU_CNTL_MASK;
+        if (on)
+                l |= (MMU_CNTL_MMU_EN | MMU_CNTL_TWL_EN);
+        else
+                l |= (MMU_CNTL_MMU_EN);
+
+        iommu_write_reg(obj, l, MMU_CNTL);
+}
+
+
 static int omap2_iommu_enable(struct iommu *obj)
 {
         u32 l, pa;
@@ -100,13 +120,9 @@ static int omap2_iommu_enable(struct iommu *obj)
         l |= (MMU_SYS_IDLE_SMART | MMU_SYS_AUTOIDLE);
         iommu_write_reg(obj, l, MMU_SYSCONFIG);
 
-        iommu_write_reg(obj, MMU_IRQ_TWL_MASK, MMU_IRQENABLE);
         iommu_write_reg(obj, pa, MMU_TTB);
 
-        l = iommu_read_reg(obj, MMU_CNTL);
-        l &= ~MMU_CNTL_MASK;
-        l |= (MMU_CNTL_MMU_EN | MMU_CNTL_TWL_EN);
-        iommu_write_reg(obj, l, MMU_CNTL);
+        __iommu_set_twl(obj, true);
 
         return 0;
 }
@@ -122,6 +138,11 @@ static void omap2_iommu_disable(struct iommu *obj)
         dev_dbg(obj->dev, "%s is shutting down\n", obj->name);
 }
 
+static void omap2_iommu_set_twl(struct iommu *obj, bool on)
+{
+        __iommu_set_twl(obj, false);
+}
+
 static u32 omap2_iommu_fault_isr(struct iommu *obj, u32 *ra)
 {
         int i;
@@ -304,6 +325,7 @@ static const struct iommu_functions omap2_iommu_ops = {
 
         .enable         = omap2_iommu_enable,
         .disable        = omap2_iommu_disable,
+        .set_twl        = omap2_iommu_set_twl,
         .fault_isr      = omap2_iommu_fault_isr,
 
         .tlb_read_cr    = omap2_tlb_read_cr,