RE: [PATCH -next] ACPI/IORT: Fix build error implicit-function-declaration

[Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>]

> -----Original Message-----
> From: renzhijie
> Sent: 24 July 2022 12:54
> To: lpieralisi@kernel.org; Guohanjun (Hanjun Guo)
> <guohanjun@huawei.com>; sudeep.holla@arm.com; rafael@kernel.org;
> lenb@kernel.org; Shameerali Kolothum Thodi
> <shameerali.kolothum.thodi@huawei.com>; jroedel@suse.de;
> robin.murphy@arm.com
> Cc: linux-acpi@vger.kernel.org; linux-arm-kernel@lists.infradead.org;
> linux-kernel@vger.kernel.org; renzhijie <renzhijie2@huawei.com>
> Subject: [PATCH -next] ACPI/IORT: Fix build error
> implicit-function-declaration
> 
> If CONFIG_ACPI_IORT=y and CONFIG_IOMMU_API is not set,
> make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu-, will be failed, like
> this:
> 
> drivers/acpi/arm64/iort.c: In function ‘iort_get_rmr_sids’:
> drivers/acpi/arm64/iort.c:1406:2: error: implicit declaration of function
> ‘iort_iommu_rmr_get_resv_regions’; did you mean
> ‘iort_iommu_get_resv_regions’? [-Werror=implicit-function-declaration]
>   iort_iommu_rmr_get_resv_regions(iommu_fwnode, NULL, head);
>   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>   iort_iommu_get_resv_regions
> cc1: some warnings being treated as errors
> make[3]: *** [drivers/acpi/arm64/iort.o] Error 1

Thanks for spotting this.

> The function iort_iommu_rmr_get_resv_regions() is declared at #ifdef
> CONFIG_IOMMU_API area, and the callers of  iort_get_rmr_sids() and
> iort_put_rmr_sids() would select IOMMU_API.
> To fix this error, move the definitions to #ifdef CONFIG_IOMMU_API area.

That makes sense. And the only callers of these are SMMU drivers I think we
don't need stub functions under !CONFIG_IOMMU_API(Lorenzo, could you
please double check this). 

Nit: Please wrap the commit description to a max of 75 chars per line.

Thanks.
Shameer

> 
> Fixes: e302eea8f497 ("ACPI/IORT: Add a helper to retrieve RMR info
> directly")
> Signed-off-by: Ren Zhijie <renzhijie2@huawei.com>
> ---
>  drivers/acpi/arm64/iort.c | 56 +++++++++++++++++++--------------------
>  1 file changed, 28 insertions(+), 28 deletions(-)
> 
> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> index cd1349d3544e..ca2aed86b540 100644
> --- a/drivers/acpi/arm64/iort.c
> +++ b/drivers/acpi/arm64/iort.c
> @@ -1162,6 +1162,34 @@ void iort_iommu_get_resv_regions(struct device
> *dev, struct list_head *head)
>  	iort_iommu_rmr_get_resv_regions(fwspec->iommu_fwnode, dev,
> head);
>  }
> 
> +/**
> + * iort_get_rmr_sids - Retrieve IORT RMR node reserved regions with
> + *                     associated StreamIDs information.
> + * @iommu_fwnode: fwnode associated with IOMMU
> + * @head: Resereved region list
> + */
> +void iort_get_rmr_sids(struct fwnode_handle *iommu_fwnode,
> +		       struct list_head *head)
> +{
> +	iort_iommu_rmr_get_resv_regions(iommu_fwnode, NULL, head);
> +}
> +EXPORT_SYMBOL_GPL(iort_get_rmr_sids);
> +
> +/**
> + * iort_put_rmr_sids - Free memory allocated for RMR reserved regions.
> + * @iommu_fwnode: fwnode associated with IOMMU
> + * @head: Resereved region list
> + */
> +void iort_put_rmr_sids(struct fwnode_handle *iommu_fwnode,
> +		       struct list_head *head)
> +{
> +	struct iommu_resv_region *entry, *next;
> +
> +	list_for_each_entry_safe(entry, next, head, list)
> +		entry->free(NULL, entry);
> +}
> +EXPORT_SYMBOL_GPL(iort_put_rmr_sids);
> +
>  static inline bool iort_iommu_driver_enabled(u8 type)
>  {
>  	switch (type) {
> @@ -1394,34 +1422,6 @@ int iort_dma_get_ranges(struct device *dev, u64
> *size)
>  		return nc_dma_get_range(dev, size);
>  }
> 
> -/**
> - * iort_get_rmr_sids - Retrieve IORT RMR node reserved regions with
> - *                     associated StreamIDs information.
> - * @iommu_fwnode: fwnode associated with IOMMU
> - * @head: Resereved region list
> - */
> -void iort_get_rmr_sids(struct fwnode_handle *iommu_fwnode,
> -		       struct list_head *head)
> -{
> -	iort_iommu_rmr_get_resv_regions(iommu_fwnode, NULL, head);
> -}
> -EXPORT_SYMBOL_GPL(iort_get_rmr_sids);
> -
> -/**
> - * iort_put_rmr_sids - Free memory allocated for RMR reserved regions.
> - * @iommu_fwnode: fwnode associated with IOMMU
> - * @head: Resereved region list
> - */
> -void iort_put_rmr_sids(struct fwnode_handle *iommu_fwnode,
> -		       struct list_head *head)
> -{
> -	struct iommu_resv_region *entry, *next;
> -
> -	list_for_each_entry_safe(entry, next, head, list)
> -		entry->free(NULL, entry);
> -}
> -EXPORT_SYMBOL_GPL(iort_put_rmr_sids);
> -
>  static void __init acpi_iort_register_irq(int hwirq, const char *name,
>  					  int trigger,
>  					  struct resource *res)
> --
> 2.17.1