Re: [PATCH v2 3/9] ACPI: APEI: EINJ: Fix kernel test robot sparse warning

[Jonathan Cameron <Jonathan.Cameron@huawei.com>]

On Thu,  5 Dec 2024 13:18:48 -0800
Zaid Alali <zaidal@os.amperecomputing.com> wrote:

> This patch fixes the kernel test robot warning reported here:
> https://lore.kernel.org/all/202410241620.oApALow5-lkp@intel.com/
> 
> Signed-off-by: Zaid Alali <zaidal@os.amperecomputing.com>
> ---
>  drivers/acpi/apei/einj-core.c | 41 +++++++++++++++++++++--------------
>  1 file changed, 25 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/acpi/apei/einj-core.c b/drivers/acpi/apei/einj-core.c
> index 04731a5b01fa..74dfb3daba50 100644
> --- a/drivers/acpi/apei/einj-core.c
> +++ b/drivers/acpi/apei/einj-core.c
> @@ -215,20 +215,22 @@ static void check_vendor_extension(u64 paddr,
>  {
>  	int	offset = v5param->vendor_extension;
>  	struct	vendor_error_type_extension *v;
> +	void __iomem *p;
>  	u32	sbdf;
>  
>  	if (!offset)
>  		return;
> -	v = acpi_os_map_iomem(paddr + offset, sizeof(*v));
> -	if (!v)
> +	p = acpi_os_map_iomem(paddr + offset, sizeof(*v));
> +	if (!p)
>  		return;
> +	v = __io_virt(p);

That's a nasty forced cast. Far as I can tell all this code
should not be assuming it can just cast away the __iomem

I think it should be fixed by using readl() etc or
memcpy_fromio()

Maybe it is safe to just ignore the marking for all current ACPI
platforms, I'm not sure.  This isn't a high performance path so
personally I'd just do it the generic way even if it is not
strictly necessary.

Jonathan



>  	get_oem_vendor_struct(paddr, offset, v);
>  	sbdf = v->pcie_sbdf;
>  	sprintf(vendor_dev, "%x:%x:%x.%x vendor_id=%x device_id=%x rev_id=%x\n",
>  		sbdf >> 24, (sbdf >> 16) & 0xff,
>  		(sbdf >> 11) & 0x1f, (sbdf >> 8) & 0x7,
>  		 v->vendor_id, v->device_id, v->rev_id);
> -	acpi_os_unmap_iomem(v, sizeof(*v));
> +	acpi_os_unmap_iomem(p, sizeof(*v));
>  }
>  
>  static void *einj_get_parameter_address(void)
> @@ -253,9 +255,11 @@ static void *einj_get_parameter_address(void)
>  	}
>  	if (pa_v5) {
>  		struct set_error_type_with_address *v5param;
> +		void __iomem *p;
>  
> -		v5param = acpi_os_map_iomem(pa_v5, sizeof(*v5param));
> -		if (v5param) {
> +		p = acpi_os_map_iomem(pa_v5, sizeof(*v5param));
> +		if (p) {
> +			v5param = __io_virt(p);
>  			acpi5 = 1;
>  			check_vendor_extension(pa_v5, v5param);
>  			return v5param;
> @@ -263,12 +267,14 @@ static void *einj_get_parameter_address(void)
>  	}
>  	if (param_extension && pa_v4) {
>  		struct einj_parameter *v4param;
> +		void __iomem *p;
>  
> -		v4param = acpi_os_map_iomem(pa_v4, sizeof(*v4param));
> -		if (!v4param)
> +		p = acpi_os_map_iomem(pa_v4, sizeof(*v4param));
> +		if (!p)
>  			return NULL;
> +		v4param = __io_virt(p);
>  		if (v4param->reserved1 || v4param->reserved2) {
> -			acpi_os_unmap_iomem(v4param, sizeof(*v4param));
> +			acpi_os_unmap_iomem(p, sizeof(*v4param));
>  			return NULL;
>  		}
>  		return v4param;
> @@ -325,6 +331,7 @@ static int __einj_error_trigger(u64 trigger_paddr, u32 type,
>  	u32 table_size;
>  	int rc = -EIO;
>  	struct acpi_generic_address *trigger_param_region = NULL;
> +	void __iomem *p;
>  
>  	r = request_mem_region(trigger_paddr, sizeof(*trigger_tab),
>  			       "APEI EINJ Trigger Table");
> @@ -335,11 +342,12 @@ static int __einj_error_trigger(u64 trigger_paddr, u32 type,
>  			    sizeof(*trigger_tab) - 1);
>  		goto out;
>  	}
> -	trigger_tab = ioremap_cache(trigger_paddr, sizeof(*trigger_tab));
> -	if (!trigger_tab) {
> +	p = ioremap_cache(trigger_paddr, sizeof(*trigger_tab));
> +	if (!p) {
>  		pr_err("Failed to map trigger table!\n");
>  		goto out_rel_header;
>  	}
> +	trigger_tab = __io_virt(p);
>  	rc = einj_check_trigger_header(trigger_tab);
>  	if (rc) {
>  		pr_warn(FW_BUG "Invalid trigger error action table.\n");
> @@ -361,12 +369,13 @@ static int __einj_error_trigger(u64 trigger_paddr, u32 type,
>  		       (unsigned long long)trigger_paddr + table_size - 1);
>  		goto out_rel_header;
>  	}
> -	iounmap(trigger_tab);
> -	trigger_tab = ioremap_cache(trigger_paddr, table_size);
> -	if (!trigger_tab) {
> +	iounmap(p);
> +	p = ioremap_cache(trigger_paddr, table_size);
> +	if (!p) {
>  		pr_err("Failed to map trigger table!\n");
>  		goto out_rel_entry;
>  	}
> +	trigger_tab = __io_virt(p);
>  	trigger_entry = (struct acpi_whea_header *)
>  		((char *)trigger_tab + sizeof(struct acpi_einj_trigger));
>  	apei_resources_init(&trigger_resources);
> @@ -424,8 +433,8 @@ static int __einj_error_trigger(u64 trigger_paddr, u32 type,
>  out_rel_header:
>  	release_mem_region(trigger_paddr, sizeof(*trigger_tab));
>  out:
> -	if (trigger_tab)
> -		iounmap(trigger_tab);
> +	if (p)
> +		iounmap(p);
>  
>  	return rc;
>  }
> @@ -860,7 +869,7 @@ static void __exit einj_remove(struct platform_device *pdev)
>  			sizeof(struct set_error_type_with_address) :
>  			sizeof(struct einj_parameter);
>  
> -		acpi_os_unmap_iomem(einj_param, size);
> +		acpi_os_unmap_iomem((void __iomem *)einj_param, size);
>  		if (vendor_errors.size)
>  			acpi_os_unmap_memory(vendor_errors.data, vendor_errors.size);
>  	}