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()".
> @@ -304,6 +319,7 @@ static const struct iommu_functions omap2_iommu_ops = {
>
> .enable = omap2_iommu_enable,
> .disable = omap2_iommu_disable,
> + .set_twl = omap2_iommu_set_twl,
> .fault_isr = omap2_iommu_fault_isr,
>
> .tlb_read_cr = omap2_tlb_read_cr,
> diff --git a/arch/arm/plat-omap/include/plat/iommu.h b/arch/arm/plat-omap/include/plat/iommu.h
> index 0752af9..33c7d41 100644
> --- a/arch/arm/plat-omap/include/plat/iommu.h
> +++ b/arch/arm/plat-omap/include/plat/iommu.h
> @@ -80,6 +80,7 @@ struct iommu_functions {
>
> int (*enable)(struct iommu *obj);
> void (*disable)(struct iommu *obj);
> + void (*set_twl)(struct iommu *obj, bool on);
> u32 (*fault_isr)(struct iommu *obj, u32 *ra);
This could be like the following, which also keeps the order of the
above "struct iommu_functions".
Modified arch/arm/mach-omap2/iommu2.c
diff --git a/arch/arm/mach-omap2/iommu2.c b/arch/arm/mach-omap2/iommu2.c
index 3cfe1c4..c87f662 100644
--- a/arch/arm/mach-omap2/iommu2.c
+++ b/arch/arm/mach-omap2/iommu2.c
@@ -66,7 +66,7 @@
((pgsz) == MMU_CAM_PGSZ_4K) ? 0xfffff000 : 0)
-static void omap2_iommu_set_twl(struct iommu *obj, bool on)
+static void __iommu_set_twl(struct iommu *obj, bool on)
{
u32 l = iommu_read_reg(obj, MMU_CNTL);
@@ -121,7 +121,7 @@ static int omap2_iommu_enable(struct iommu *obj)
iommu_write_reg(obj, pa, MMU_TTB);
- omap2_iommu_set_twl(obj, true);
+ __iommu_set_twl(obj, true);
return 0;
}
@@ -137,6 +137,11 @@ static void omap2_iommu_disable(struct iommu *obj)
dev_dbg(obj->dev, "%s is shutting down\n", obj->name);
}
+static void omap2_iommu_set_twl(struct iommu *obj, bool on)
+{
+ __iommu_set_twl(obj, on);
+}
+
static u32 omap2_iommu_fault_isr(struct iommu *obj, u32 *ra)
{
int i;
--
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