Re: [PATCH 3/3] net: ipa: Grab IMEM slice base/size from DTS

[Simon Horman <horms@kernel.org>]

On Fri, May 23, 2025 at 01:08:34AM +0200, Konrad Dybcio wrote:
> From: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
> 
> This is a detail that differ per chip, and not per IPA version (and
> there are cases of the same IPA versions being implemented across very
> very very different SoCs).
> 
> This region isn't actually used by the driver, but we most definitely
> want to iommu-map it, so that IPA can poke at the data within.
> 
> Signed-off-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>

It looks like these patches are for net-next. For future reference,
it's best to note that in the subject.

  Subject: [PATCH net-next 3/3 v2] ...

> ---
>  drivers/net/ipa/ipa_data.h |  3 +++
>  drivers/net/ipa/ipa_mem.c  | 18 ++++++++++++++++++
>  2 files changed, 21 insertions(+)
> 
> diff --git a/drivers/net/ipa/ipa_data.h b/drivers/net/ipa/ipa_data.h
> index 2fd03f0799b207833f9f2b421ce043534720d718..a384df91b5ee3ed2db9c7812ad43d03424b82a6f 100644
> --- a/drivers/net/ipa/ipa_data.h
> +++ b/drivers/net/ipa/ipa_data.h
> @@ -185,8 +185,11 @@ struct ipa_resource_data {
>  struct ipa_mem_data {
>  	u32 local_count;
>  	const struct ipa_mem *local;
> +
> +	/* DEPRECATED (now passed via DT) fallback data, varies per chip and not per IPA version */

For Networking code, please restrict lines to 80 columns wide or less where
that can be done without reducing readability (which is the case here).

	/* DEPRECATED (now passed via DT) fallback data,
	 * varies per chip and not per IPA version */

>  	u32 imem_addr;
>  	u32 imem_size;
> +
>  	u32 smem_size;
>  };
>  
> diff --git a/drivers/net/ipa/ipa_mem.c b/drivers/net/ipa/ipa_mem.c
> index 835a3c9c1fd47167da3396424a1653ebcae81d40..020508ab47d92b5cca9d5b467e3fef46936b4a82 100644
> --- a/drivers/net/ipa/ipa_mem.c
> +++ b/drivers/net/ipa/ipa_mem.c
> @@ -7,6 +7,7 @@
>  #include <linux/dma-mapping.h>
>  #include <linux/io.h>
>  #include <linux/iommu.h>
> +#include <linux/of_address.h>
>  #include <linux/platform_device.h>
>  #include <linux/types.h>
>  
> @@ -617,7 +618,9 @@ static void ipa_smem_exit(struct ipa *ipa)
>  int ipa_mem_init(struct ipa *ipa, struct platform_device *pdev,
>  		 const struct ipa_mem_data *mem_data)
>  {
> +	struct device_node *ipa_slice_np;
>  	struct device *dev = &pdev->dev;
> +	u32 imem_base, imem_size;
>  	struct resource *res;
>  	int ret;
>  
> @@ -656,6 +659,21 @@ int ipa_mem_init(struct ipa *ipa, struct platform_device *pdev,
>  	ipa->mem_addr = res->start;
>  	ipa->mem_size = resource_size(res);
>  
> +	ipa_slice_np = of_parse_phandle(dev->of_node, "sram", 0);
> +	if (ipa_slice_np) {
> +		ret = of_address_to_resource(ipa_slice_np, 0, res);
> +		of_node_put(ipa_slice_np);
> +		if (ret)
> +			return ret;
> +
> +		imem_base = res->start;
> +		imem_size = resource_size(res);
> +	} else {
> +		/* Backwards compatibility for DTs lacking an explicit reference */

Ditto.

> +		imem_base = mem_data->imem_addr;
> +		imem_size = mem_data->imem_size;
> +	}
> +
>  	ret = ipa_imem_init(ipa, mem_data->imem_addr, mem_data->imem_size);

I think you also need to update this line to use the local
variables imem_addr and imem_size.

>  	if (ret)
>  		goto err_unmap;

Please do observe the 24h rule [1] if you post a v2 of this patchset.

[1] https://docs.kernel.org/process/maintainer-netdev.html#resending-after-review