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

[Alex Elder <elder@ieee.org>]

On 5/22/25 6:08 PM, 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>

You need to fix something here, but it otherwise look good.

Please fix, and assuming you do:

Reviewed-by: Alex Elder <elder@riscstar.com>

> ---
>   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 */
>   	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 */
> +		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);

You want to pass imem_base and imem_size here?

					-Alex

>   	if (ret)
>   		goto err_unmap;
>