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

["Kanigeri, Hari" <h-kanigeri2@xxxxxx>]

>From bcdd232666a163d2661d704f9c21d055bacfd178 Mon Sep 17 00:00:00 2001
From: Hari Kanigeri <h-kanigeri2@xxxxxx>
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-kanigeri2@xxxxxx>
---
 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

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