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Subject: Re: [PATCH -next] powerpc/pseries/memory-hotplug: Fix return value
 type of find_aa_index
To:     YueHaibing <yuehaibing@huawei.com>, benh@kernel.crashing.org,
        paulus@samba.org, mpe@ellerman.id.au
Cc:     linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
References: <20180921103759.24976-1-yuehaibing@huawei.com>
From:   Nathan Fontenot <nfont@linux.vnet.ibm.com>
Date:   Fri, 28 Sep 2018 15:25:19 -0500
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On 09/21/2018 05:37 AM, YueHaibing wrote:
> find_aa_index will return -1 when dlpar_clone_property fails,
> its return value type should be int. Also the caller
> update_lmb_associativity_index should use a int variable to
> get it,then compared with 0.

The aa_index that we are handling here is defined as an unsigned value
in the PAPR so I'm a little hesitant in changing it to a signed value.
Also, changing the aa_index to be signed, we still assign it to the
u32 lmb->aa_index.

There are some other places where the aa_index is treated as a signed value
in finc_aa_index(). Perhaps the better solution is use an rc value to track
the validation of finding the aa_index instead of the aa_index value itself.

-Nathan 

> 
> Fixes: c05a5a40969e ("powerpc/pseries: Dynamic add entires to associativity lookup array")
> Signed-off-by: YueHaibing <yuehaibing@huawei.com>
> ---
>  arch/powerpc/platforms/pseries/hotplug-memory.c | 7 +++----
>  1 file changed, 3 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c
> index 9a15d39..6aad17c 100644
> --- a/arch/powerpc/platforms/pseries/hotplug-memory.c
> +++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
> @@ -101,13 +101,12 @@ static struct property *dlpar_clone_property(struct property *prop,
>  	return new_prop;
>  }
> 
> -static u32 find_aa_index(struct device_node *dr_node,
> +static int find_aa_index(struct device_node *dr_node,
>  			 struct property *ala_prop, const u32 *lmb_assoc)
>  {
>  	u32 *assoc_arrays;
> -	u32 aa_index;
>  	int aa_arrays, aa_array_entries, aa_array_sz;
> -	int i, index;
> +	int i, index, aa_index;
> 
>  	/*
>  	 * The ibm,associativity-lookup-arrays property is defined to be
> @@ -168,7 +167,7 @@ static int update_lmb_associativity_index(struct drmem_lmb *lmb)
>  	struct device_node *parent, *lmb_node, *dr_node;
>  	struct property *ala_prop;
>  	const u32 *lmb_assoc;
> -	u32 aa_index;
> +	int aa_index;
> 
>  	parent = of_find_node_by_path("/");
>  	if (!parent)
>