From: Hiroshi DOYU <Hiroshi.DOYU@xxxxxxxxx>
Subject: Re: [PATCH 2/2] omap: iommu-add functionality to get TLB miss interrupt
Date: Fri, 21 May 2010 08:45:14 +0300 (EEST)
> Hi Hari,
>
> From: ext Hari Kanigeri <h-kanigeri2@xxxxxx>
> Subject: [PATCH 2/2] omap: iommu-add functionality to get TLB miss interrupt
> Date: Thu, 20 May 2010 23:10:23 +0200
>
>> 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@xxxxxx>
>> Signed-off-by: Ramesh Gupta <grgupta@xxxxxx>
>> Signed-off-by: Hiroshi Doyu <Hiroshi.DOYU@xxxxxxxxx>
>> ---
>> arch/arm/mach-omap2/iommu2.c | 26 +++++++++++++++++++++-----
>> arch/arm/plat-omap/include/plat/iommu.h | 2 ++
>> arch/arm/plat-omap/iommu.c | 17 +++++++++++++++++
>> 3 files changed, 40 insertions(+), 5 deletions(-)
>>
>> diff --git a/arch/arm/mach-omap2/iommu2.c b/arch/arm/mach-omap2/iommu2.c
>> index ebbdae2..3cfe1c4 100644
>> --- a/arch/arm/mach-omap2/iommu2.c
>> +++ b/arch/arm/mach-omap2/iommu2.c
>> @@ -65,6 +65,25 @@
>> ((pgsz) == MMU_CAM_PGSZ_64K) ? 0xffff0000 : \
>> ((pgsz) == MMU_CAM_PGSZ_4K) ? 0xfffff000 : 0)
>>
>> +
>> +static void omap2_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 +119,9 @@ 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);
>> + omap2_iommu_set_twl(obj, true);
>>
>> return 0;
>> }
>
> nitpick: The function prefix "omap2_iommu_" are used to indicate that
> this prefixed function belongs to "omap2_iommu_ops" to provide iommu
> basic functionalities for the above layer. It's better to avoid to use
> the prefixed function in the same prefixed ones, IOW, nested like
> above, where "omap2_iommu_enable()" calls "omap2_iommu_set_twl()"
> internally. It's can be considered as a violation of layer? Same to
> "omap2_iommu_disable()".
For the case of "omap2_iommu_disable()", I attached the fix.
>From 47994f0cb3ea3b3846f3b92bc9ab16f82d112d0b Mon Sep 17 00:00:00 2001
From: Hiroshi DOYU <Hiroshi.DOYU@xxxxxxxxx>
Date: Fri, 21 May 2010 12:17:32 +0300
Subject: [PATCH 1/1] omap iommu: move iommu_disable at fault to the above layer
The function prefix "omap2_iommu_" indicates that the prefixed
function belongs to "omap2_iommu_ops" to provide iommu basic
functionalities for the above layers. It's better to avoid the
prefixed function called in the same prefixed ones internally, like
nested here. Now "iommu_disable" is called just after fault_isr() in
the above layer. This is a little bit more sensible to keep the
consistency of module layers.
Signed-off-by: Hiroshi DOYU <Hiroshi.DOYU@xxxxxxxxx>
---
arch/arm/mach-omap2/iommu2.c | 2 +-
arch/arm/plat-omap/iommu.c | 2 ++
2 files changed, 3 insertions(+), 1 deletions(-)
diff --git a/arch/arm/mach-omap2/iommu2.c b/arch/arm/mach-omap2/iommu2.c
index ebbdae2..bcd816e 100644
--- a/arch/arm/mach-omap2/iommu2.c
+++ b/arch/arm/mach-omap2/iommu2.c
@@ -151,7 +151,7 @@ static u32 omap2_iommu_fault_isr(struct iommu *obj, u32 *ra)
printk("\n");
iommu_write_reg(obj, stat, MMU_IRQSTATUS);
- omap2_iommu_disable(obj);
+
return stat;
}
diff --git a/arch/arm/plat-omap/iommu.c b/arch/arm/plat-omap/iommu.c
index 3381070..7245de4 100644
--- a/arch/arm/plat-omap/iommu.c
+++ b/arch/arm/plat-omap/iommu.c
@@ -783,6 +783,8 @@ static irqreturn_t iommu_fault_handler(int irq, void *data)
if (!stat)
return IRQ_HANDLED;
+ iommu_disable(obj);
+
iopgd = iopgd_offset(obj, da);
if (!iopgd_is_table(*iopgd)) {
--
1.7.1.rc1
