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>

diff --git a/arch/arm/mach-omap2/iommu2.c b/arch/arm/mach-omap2/iommu2.c
index ebbdae262f78a8a09914b966da31cce55176e5b2..edf7cd4b6553071c9ba119bec9471f977ed02f38 100644 (file)
--- 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,

diff --git a/arch/arm/plat-omap/include/plat/iommu.h b/arch/arm/plat-omap/include/plat/iommu.h
index 0752af9d099e017e216887c7f4d67a01d283330d..33c7d41cb6a55b1f166f563f76f79ffd0acf8481 100644 (file)
--- a/arch/arm/plat-omap/include/plat/iommu.h
+++ b/arch/arm/plat-omap/include/plat/iommu.h
@@ -80,6 +80,7 @@ struct iommu_functions {
 
        int (*enable)(struct iommu *obj);
        void (*disable)(struct iommu *obj);
+       void (*set_twl)(struct iommu *obj, bool on);
        u32 (*fault_isr)(struct iommu *obj, u32 *ra);
 
        void (*tlb_read_cr)(struct iommu *obj, struct cr_regs *cr);
@@ -143,6 +144,7 @@ extern void iotlb_cr_to_e(struct cr_regs *cr, struct iotlb_entry *e);
 extern u32 iotlb_cr_to_virt(struct cr_regs *cr);
 
 extern int load_iotlb_entry(struct iommu *obj, struct iotlb_entry *e);
+extern void iommu_set_twl(struct iommu *obj, bool on);
 extern void flush_iotlb_page(struct iommu *obj, u32 da);
 extern void flush_iotlb_range(struct iommu *obj, u32 start, u32 end);
 extern void flush_iotlb_all(struct iommu *obj);

diff --git a/arch/arm/plat-omap/iommu.c b/arch/arm/plat-omap/iommu.c
index 341c48179ee01720ae7cae76768c91e3decddb33..688ae66bb8fc552647aab7676496150c1e9a8c27 100644 (file)
--- a/arch/arm/plat-omap/iommu.c
+++ b/arch/arm/plat-omap/iommu.c
@@ -370,6 +370,23 @@ void flush_iotlb_all(struct iommu *obj)
 }
 EXPORT_SYMBOL_GPL(flush_iotlb_all);
 
+/**
+ * iommu_set_twl - enable/disable table walking logic
+ * @obj:       target iommu
+ * @on:                enable/disable
+ *
+ * Function used to enable/disable TWL. If one wants to work
+ * exclusively with locked TLB entries and receive notifications
+ * for TLB miss then call this function to disable TWL.
+ */
+void iommu_set_twl(struct iommu *obj, bool on)
+{
+       clk_enable(obj->clk);
+       arch_iommu->set_twl(obj, on);
+       clk_disable(obj->clk);
+}
+EXPORT_SYMBOL_GPL(iommu_set_twl);
+
 #if defined(CONFIG_OMAP_IOMMU_DEBUG_MODULE)
 
 ssize_t iommu_dump_ctx(struct iommu *obj, char *buf, ssize_t bytes)