Subject: Re: [PATCH linux-next] iommu: Enable LPAE pagetable on ARM only

From: Laurent Pinchart <laurent.pinchart-ryLnwIuWjnjg/[email-masked]>
Date: Mon, 23 Feb 2015 18:52:41 +0200

Hi Vincent,

Thank you for the patch.

On Sunday 22 February 2015 17:09:06 Vincent Stehlé wrote:
> LPAE iommu page table makes sense only for ARM architecture. Add the
> corresponding dependency in Kconfig.
> 
> This fixes the following runtime warnings on PA-RISC architecture:

I suppose this is caused by the selftest code ?

>   WARNING: at drivers/iommu/io-pgtable-arm.c:413
>   Modules linked in:
>   CPU: 0 PID: 1 Comm: swapper/0 Not tainted
> 3.19.0-next-20150222-00002-gc420256 #2 task: 17ca0000 ti: 17ca8000 task.ti:
> 17ca8000
> 
>        YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI
>   PSW: 00000000000001001111111100001111 Not tainted
>   r00-03  0004ff0f 0000001b 104871b0 17ca83c0
>   r04-07  00001000 00000000 00000000 00000000
>   r08-11  00000000 40001000 1013b36c 17ca8248
>   r12-15  00000080 17e712c0 00000000 17c5e100
>   r16-19  0000000c 105d8eb0 40001000 ffffffff
>   r20-23  00000000 00800020 1048717c 00000000
>   r24-27  00001000 00000000 00000009 10774ce0
>   r28-31  00000000 00000027 17ca8480 10486d44
>   sr00-03  00000000 00000000 00000000 00000000
>   sr04-07  00000000 00000000 00000000 00000000
> 
>   IASQ: 00000000 00000000 IAOQ: 10486df4 10486df8
>    IIR: 03ffe01f    ISR: 00000000  IOR: 17c86e54
>    CPU:        0   CR30: 17ca8000 CR31: 00000002
>    ORIG_R28: 00000001
>    IAOQ[0]: __arm_lpae_unmap+0x144/0x4cc
>    IAOQ[1]: __arm_lpae_unmap+0x148/0x4cc
>    RP(r2): arm_lpae_unmap+0x34/0x6c
>   Backtrace:
>    [<104871b0>] arm_lpae_unmap+0x34/0x6c
>    [<10127944>] 0x10127944
>    [<10168ee0>] do_one_initcall+0x128/0x1dc
>    [<101028fc>] 0x101028fc
>    [<10161b48>] kernel_init+0x1c/0x118
>    [<1015d01c>] end_fault_vector+0x1c/0x24
>    [<101762ec>] save_stack_trace+0x28/0x60
> 
> Signed-off-by: Vincent Stehlé <[email-masked]>
> Cc: Laurent Pinchart <laurent.pinchart-ryLnwIuWjnjg/[email-masked]>
> Cc: Will Deacon <[email-masked]>
> ---
> 
> 
> Hi,
> 
> This can be seen with e.g. Linux next-20150222 on parisc with allmodconfig.
> 
> Best regards,
> 
> V.
> 
> 
>  drivers/iommu/Kconfig | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
> index baa0d97..c73fd72 100644
> --- a/drivers/iommu/Kconfig
> +++ b/drivers/iommu/Kconfig
> @@ -22,6 +22,7 @@ config IOMMU_IO_PGTABLE
> 
>  config IOMMU_IO_PGTABLE_LPAE
>  	bool "ARMv7/v8 Long Descriptor Format"
> +	depends on ARM

How about ARM || COMPILE_TEST ? It can still be useful to compile the module 
on other architectures.

>  	select IOMMU_IO_PGTABLE
>  	help
>  	  Enable support for the ARM long descriptor pagetable format.

-- 
Regards,

Laurent Pinchart