omap iommu: add TLB preservation support

This patch adds TLB preservation support to IOMMU module

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

1 files changed, 26 insertions, 17 deletions

diff --git a/arch/arm/plat-omap/iommu.c b/arch/arm/plat-omap/iommu.c
index 0e137663349c..1e83facb6b77 100644
--- a/arch/arm/plat-omap/iommu.c
+++ b/arch/arm/plat-omap/iommu.c
@@ -172,15 +172,12 @@ static void iotlb_lock_get(struct iommu *obj, struct iotlb_lock *l)
         l->base = MMU_LOCK_BASE(val);
         l->vict = MMU_LOCK_VICT(val);
 
-        BUG_ON(l->base != 0); /* Currently no preservation is used */
 }
 
 static void iotlb_lock_set(struct iommu *obj, struct iotlb_lock *l)
 {
         u32 val;
 
-        BUG_ON(l->base != 0); /* Currently no preservation is used */
-
         val = (l->base << MMU_LOCK_BASE_SHIFT);
         val |= (l->vict << MMU_LOCK_VICT_SHIFT);
 
@@ -231,22 +228,32 @@ int load_iotlb_entry(struct iommu *obj, struct iotlb_entry *e)
 
         clk_enable(obj->clk);
 
-        for (i = 0; i < obj->nr_tlb_entries; i++) {
-                struct cr_regs tmp;
-
-                iotlb_lock_get(obj, &l);
-                l.vict = i;
-                iotlb_lock_set(obj, &l);
-                iotlb_read_cr(obj, &tmp);
-                if (!iotlb_cr_valid(&tmp))
-                        break;
-        }
-
-        if (i == obj->nr_tlb_entries) {
-                dev_dbg(obj->dev, "%s: full: no entry\n", __func__);
+        iotlb_lock_get(obj, &l);
+        if (l.base == obj->nr_tlb_entries) {
+                dev_warn(obj->dev, "%s: preserve entries full\n", __func__);
                 err = -EBUSY;
                 goto out;
         }
+        if (!e->prsvd) {
+                for (i = l.base; i < obj->nr_tlb_entries; i++) {
+                        struct cr_regs tmp;
+
+                        iotlb_lock_get(obj, &l);
+                        l.vict = i;
+                        iotlb_lock_set(obj, &l);
+                        iotlb_read_cr(obj, &tmp);
+                        if (!iotlb_cr_valid(&tmp))
+                                break;
+                }
+                if (i == obj->nr_tlb_entries) {
+                        dev_dbg(obj->dev, "%s: full: no entry\n", __func__);
+                        err = -EBUSY;
+                        goto out;
+                }
+        } else {
+                l.vict = l.base;
+                iotlb_lock_set(obj, &l);
+        }
 
         cr = iotlb_alloc_cr(obj, e);
         if (IS_ERR(cr)) {
@@ -257,9 +264,11 @@ int load_iotlb_entry(struct iommu *obj, struct iotlb_entry *e)
         iotlb_load_cr(obj, cr);
         kfree(cr);
 
+        if (e->prsvd)
+                l.base++;
         /* increment victim for next tlb load */
         if (++l.vict == obj->nr_tlb_entries)
-                l.vict = 0;
+                l.vict = l.base;
         iotlb_lock_set(obj, &l);
 out:
         clk_disable(obj->clk);