[PATCH] ARM: OMAP add TLB preservation support to IOMMU

[Kanigeri, Hari]

>From bcdd232666a163d2661d704f9c21d055bacfd178 Mon Sep 17 00:00:00 2001
From: Hari Kanigeri <h-kanige...@ti.com>
Date: Mon, 8 Mar 2010 18:00:36 -0600
Subject: [PATCH] ARM: OMAP add TLB preservation support to IOMMU

This patch adds TLB preservation support to IOMMU module

Signed-off-by: Hari Kanigeri <h-kanige...@ti.com>
---
 arch/arm/mach-omap2/iommu2.c |    7 +++++--
 arch/arm/plat-omap/iommu.c   |   16 +++++++++-------
 2 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/arch/arm/mach-omap2/iommu2.c b/arch/arm/mach-omap2/iommu2.c
index 6f4b7cc..2735bd7 100644
--- a/arch/arm/mach-omap2/iommu2.c
+++ b/arch/arm/mach-omap2/iommu2.c
@@ -146,6 +146,8 @@ static u32 omap2_iommu_fault_isr(struct iommu *obj, u32 *ra)
        printk("\n");
 
        iommu_write_reg(obj, stat, MMU_IRQSTATUS);
+       /* Disable MMU to stop continuous generation of MMU faults */
+       omap2_iommu_disable(obj);
        return stat;
 }
 
@@ -183,7 +185,7 @@ static struct cr_regs *omap2_alloc_cr(struct iommu *obj, 
struct iotlb_entry *e)
        if (!cr)
                return ERR_PTR(-ENOMEM);
 
-       cr->cam = (e->da & MMU_CAM_VATAG_MASK) | e->prsvd | e->pgsz;
+       cr->cam = (e->da & MMU_CAM_VATAG_MASK) | e->prsvd | e->pgsz | e->valid;
        cr->ram = e->pa | e->endian | e->elsz | e->mixed;
 
        return cr;
@@ -211,7 +213,8 @@ static ssize_t omap2_dump_cr(struct iommu *obj, struct 
cr_regs *cr, char *buf)
        char *p = buf;
 
        /* FIXME: Need more detail analysis of cam/ram */
-       p += sprintf(p, "%08x %08x\n", cr->cam, cr->ram);
+       p += sprintf(p, "%08x %08x %01x\n", cr->cam, cr->ram,
+                                       (cr->cam & MMU_CAM_P) ? 1 : 0);
 
        return p - buf;
 }
diff --git a/arch/arm/plat-omap/iommu.c b/arch/arm/plat-omap/iommu.c
index 5186728..64d676e 100644
--- a/arch/arm/plat-omap/iommu.c
+++ b/arch/arm/plat-omap/iommu.c
@@ -171,15 +171,12 @@ 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);
 
@@ -241,7 +238,7 @@ int load_iotlb_entry(struct iommu *obj, struct iotlb_entry 
*e)
                        break;
        }
 
-       if (i == obj->nr_tlb_entries) {
+       if (i == obj->nr_tlb_entries || (l.base == obj->nr_tlb_entries)) {
                dev_dbg(obj->dev, "%s: full: no entry\n", __func__);
                err = -EBUSY;
                goto out;
@@ -252,13 +249,18 @@ int load_iotlb_entry(struct iommu *obj, struct 
iotlb_entry *e)
                clk_disable(obj->clk);
                return PTR_ERR(cr);
        }
-
        iotlb_load_cr(obj, cr);
        kfree(cr);
 
+       /* Increment base number if preservation is set */
+       if (e->prsvd)
+               l.base++;
        /* increment victim for next tlb load */
-       if (++l.vict == obj->nr_tlb_entries)
-               l.vict = 0;
+       if (++l.vict == obj->nr_tlb_entries) {
+               l.vict = l.base;
+               goto out;
+       }
+
        iotlb_lock_set(obj, &l);
 out:
        clk_disable(obj->clk);
-- 
1.7.0


Thank you,
Best regards,
Hari

0001-ARM-OMAP-add-TLB-preservation-support-to-IOMMU.patch
Description: 0001-ARM-OMAP-add-TLB-preservation-support-to-IOMMU.patch