Hi Hari,
From: ext Hari Kanigeri <h-kanigeri2@xxxxxx>
Subject: [PATCH 2/2] omap: iommu-add functionality to get TLB miss interrupt
Date: Tue, 18 May 2010 01:12:30 +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.
I want to keep leave the functionality to allow the locked TLB and
TWL enabled at the same time too. Is it still feasible with this?
> New interface is added to disable twl and enable TLB miss
> interrupt.
>
> Signed-off-by: Hari Kanigeri <h-kanigeri2@xxxxxx>
> Signed-off-by: Ramesh Gupta <grgupta@xxxxxx>
> ---
> arch/arm/mach-omap2/iommu2.c | 13 +++++++++++++
> arch/arm/plat-omap/include/plat/iommu.h | 2 ++
> arch/arm/plat-omap/iommu.c | 12 ++++++++++++
> 3 files changed, 27 insertions(+), 0 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/iommu2.c b/arch/arm/mach-omap2/iommu2.c
> index fcf4f4a..2e78cea 100644
> --- a/arch/arm/mach-omap2/iommu2.c
> +++ b/arch/arm/mach-omap2/iommu2.c
> @@ -124,6 +124,18 @@ static void omap2_iommu_disable(struct iommu *obj)
> dev_dbg(obj->dev, "%s is shutting down\n", obj->name);
> }
>
> +static void omap2_iommu_disable_twl(struct iommu *obj)
> +{
> + u32 l = iommu_read_reg(obj, MMU_CNTL);
> +
> + l &= ~MMU_CNTL_MASK;
> + l |= (MMU_CNTL_MMU_EN);
> + iommu_write_reg(obj, l, MMU_CNTL);
> +
> + /* Enable TLB miss interrupt */
> + iommu_write_reg(obj, MMU_IRQ_TLB_MISS_MASK, MMU_IRQENABLE);
> +}
> +
> static u32 omap2_iommu_fault_isr(struct iommu *obj, u32 *ra)
> {
> int i;
> @@ -306,6 +318,7 @@ static const struct iommu_functions omap2_iommu_ops = {
>
> .enable = omap2_iommu_enable,
> .disable = omap2_iommu_disable,
> + .disable_twl = omap2_iommu_disable_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..52a3852 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 (*disable_twl)(struct iommu *obj);
> u32 (*fault_isr)(struct iommu *obj, u32 *ra);
>
> void (*tlb_read_cr)(struct iommu *obj, struct cr_regs *cr);
> @@ -143,6 +144,7 @@ extern void iotlb_cr_to_e(struct cr_regs *cr, struct iotlb_entry *e);
> extern u32 iotlb_cr_to_virt(struct cr_regs *cr);
>
> extern int load_iotlb_entry(struct iommu *obj, struct iotlb_entry *e);
> +extern void iommu_disable_twl(struct iommu *obj);
> extern void flush_iotlb_page(struct iommu *obj, u32 da);
> extern void flush_iotlb_range(struct iommu *obj, u32 start, u32 end);
> extern void flush_iotlb_all(struct iommu *obj);
> diff --git a/arch/arm/plat-omap/iommu.c b/arch/arm/plat-omap/iommu.c
> index b2b3937..d64a4d8 100644
> --- a/arch/arm/plat-omap/iommu.c
> +++ b/arch/arm/plat-omap/iommu.c
> @@ -370,6 +370,18 @@ void flush_iotlb_all(struct iommu *obj)
> }
> EXPORT_SYMBOL_GPL(flush_iotlb_all);
>
> +/**
> + * Call this function if working with locked TLB entries and
> + * TWL disabled
> + */
nitpick: It may be better to follow this for global func.
>From linux/Documentation/kernel-doc-nano-HOWTO.txt:
...
Example kernel-doc function comment:
/**
* foobar() - short function description of foobar
* @arg1: Describe the first argument to foobar.
* @arg2: Describe the second argument to foobar.
* One can provide multiple line descriptions
* for arguments.
*
* A longer description, with more discussion of the function foobar()
* that might be useful to those using or modifying it. Begins with
* empty comment line, and may include additional embedded empty
* comment lines.
*
* The longer description can have multiple paragraphs.
*/
> +extern void iommu_disable_twl(struct iommu *obj)
extern?
> +{
> + clk_enable(obj->clk);
> + arch_iommu->disable_twl(obj);
> + clk_disable(obj->clk);
> +}
> +EXPORT_SYMBOL_GPL(iommu_disable_twl);
> +
> #if defined(CONFIG_OMAP_IOMMU_DEBUG_MODULE)
>
> ssize_t iommu_dump_ctx(struct iommu *obj, char *buf, ssize_t bytes)
> --
> 1.7.0
>
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