Re: [PATCH] xen/arm: smmuv1: Fixed stream matching register allocation

[Julien Grall <julien@xxxxxxx>]

Hi Rahul,

On 25/06/2021 17:37, Rahul Singh wrote:
> SMR allocation should be based on the number of supported stream
> matching register for each SMMU device.
>
> Issue introduced by commit 5e08586afbb90b2e2d56c175c07db77a4afa873c
> when backported the patches from Linux to XEN to fix the stream match
> conflict issue when two devices have the same stream-id.
>
> Acked-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>
> Tested-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>
> Signed-off-by: Rahul Singh <rahul.singh@xxxxxxx>
> ---
>   xen/drivers/passthrough/arm/smmu.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/xen/drivers/passthrough/arm/smmu.c 
> b/xen/drivers/passthrough/arm/smmu.c
> index d9a3a0cbf6..da2cd457d7 100644
> --- a/xen/drivers/passthrough/arm/smmu.c
> +++ b/xen/drivers/passthrough/arm/smmu.c
> @@ -149,6 +149,7 @@ typedef enum irqreturn irqreturn_t;
>   #define kzalloc(size, flags)          _xzalloc(size, sizeof(void *))
>   #define devm_kzalloc(dev, size, flags)        _xzalloc(size, sizeof(void *))
>   #define kmalloc_array(size, n, flags) _xmalloc_array(size, sizeof(void *), n)
> +#define kzalloc_array(size, n, flags)  _xzalloc_array(size, sizeof(void *), n)
>   
>   static void __iomem *devm_ioremap_resource(struct device *dev,
>                                            struct resource *res)
> @@ -2221,7 +2222,7 @@ static int arm_smmu_device_cfg_probe(struct 
> arm_smmu_device *smmu)
>                 smmu->smr_mask_mask = smr >> SMR_MASK_SHIFT;
>   
>   		/* Zero-initialised to mark as invalid */
> -               smmu->smrs = devm_kzalloc(smmu->dev, sizeof(*smmu->smrs), 
> GFP_KERNEL);
> +               smmu->smrs = kzalloc_array(sizeof(*smmu->smrs), size, 
> GFP_KERNEL);
I noticed this is already in... However, I am a bit puzzled into why 
this was switched devm_kzalloc() to kzalloc_array(). This doesn't matter 
for Xen as they are just wrappers to x*alloc() but a mention in the 
commit message would have been useful.
Also, when sending series, please remember to create a cover letter and 
number each patch.
Cheers,

--
Julien Grall