Hi Hari,
From: ext Kanigeri, Hari h-kanige...@ti.com
Subject: [PATCH] ARM: OMAP add TLB preservation support to IOMMU
Date: Fri, 16 Apr 2010 18:18:59 +0200
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);
The above comment may look a bit redundant.
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;
Good finding. This can be a separate patch.
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);
This is ok for now.
As described in FIXME comment, this cam/ram whole anaylysis can be
improved/implemented in order to display all items/bits in the end.
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)) {
The above should be dealt separately, since no vacant entry is normal,
but no room to be replaced because of preservation should be warned,
at least.
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++;
redundant comment? It tells what the code does.
/* increment victim for next tlb load */
Although the above is my comment, this looks redundant now too.
- if (++l.vict == obj-nr_tlb_entries)
- l.vict = 0;
+ if (++l.vict == obj-nr_tlb_entries) {
+ l.vict = l.base;
+ goto out;
+ }
Does the above work?
+
iotlb_lock_set(obj, l);
out:
clk_disable(obj-clk);
--
1.7.0
Thank you,
Best regards,
Hari
--
To unsubscribe from this list: send the line unsubscribe linux-omap in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
