Re: [PATCH v11 05/20] platform/x86/intel/pmt: Do not remap when using callbacks

[Rodrigo Vivi <rodrigo.vivi@intel.com>]

On Wed, Sep 23, 2026 at 11:11:20AM -0700, Michael J. Ruhl wrote:
> A callback indicates that the parent driver is responsible for accessing
> the data area.  Creating a PMT memory remap is redundant.
> 
> If a read_telem callback has been provided, do not create a remap.
> 
> Enforce API usage where necessary.
> 
> Clean up open coded resource usage.
> 
> Signed-off-by: Michael J. Ruhl <michael.j.ruhl@intel.com>

Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

> ---
>  drivers/platform/x86/intel/pmt/class.c     | 21 +++++++++++++--------
>  drivers/platform/x86/intel/pmt/class.h     |  2 +-
>  drivers/platform/x86/intel/pmt/telemetry.c |  3 +++
>  3 files changed, 17 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/platform/x86/intel/pmt/class.c b/drivers/platform/x86/intel/pmt/class.c
> index 402d51df834a..1c7a372b4fc4 100644
> --- a/drivers/platform/x86/intel/pmt/class.c
> +++ b/drivers/platform/x86/intel/pmt/class.c
> @@ -12,6 +12,7 @@
>  #include <linux/log2.h>
>  #include <linux/intel_vsec.h>
>  #include <linux/io-64-nonatomic-lo-hi.h>
> +#include <linux/ioport.h>
>  #include <linux/minmax.h>
>  #include <linux/module.h>
>  #include <linux/mm.h>
> @@ -373,7 +374,6 @@ static int intel_pmt_dev_register(struct intel_pmt_entry *entry,
>  				  struct device *parent)
>  {
>  	struct intel_vsec_device *ivdev = dev_to_ivdev(parent);
> -	struct resource res = {0};
>  	struct device *dev;
>  	int ret;
>  
> @@ -403,14 +403,19 @@ static int intel_pmt_dev_register(struct intel_pmt_entry *entry,
>  	if (!entry->size)
>  		return 0;
>  
> -	res.start = entry->base_addr;
> -	res.end = res.start + entry->size - 1;
> -	res.flags = IORESOURCE_MEM;
> +	/*
> +	 * The read_telem callback is responsible for this mapping, and may have
> +	 * different requirements for use. If the callback is present do not
> +	 * create the map.
> +	 */
> +	if (!(entry->cb && entry->cb->read_telem)) {
> +		struct resource res = DEFINE_RES_MEM(entry->base_addr, entry->size);
>  
> -	entry->base = devm_ioremap_resource(dev, &res);
> -	if (IS_ERR(entry->base)) {
> -		ret = PTR_ERR(entry->base);
> -		goto fail_ioremap;
> +		entry->base = devm_ioremap_resource(dev, &res);
> +		if (IS_ERR(entry->base)) {
> +			ret = PTR_ERR(entry->base);
> +			goto fail_ioremap;
> +		}
>  	}
>  
>  	sysfs_bin_attr_init(&entry->pmt_bin_attr);
> diff --git a/drivers/platform/x86/intel/pmt/class.h b/drivers/platform/x86/intel/pmt/class.h
> index 258cb460e61c..aeb04afb67cf 100644
> --- a/drivers/platform/x86/intel/pmt/class.h
> +++ b/drivers/platform/x86/intel/pmt/class.h
> @@ -48,7 +48,7 @@ struct intel_pmt_entry {
>  	const struct attribute_group *attr_grp;
>  	struct kobject		*kobj;
>  	void __iomem		*disc_table;
> -	void __iomem		*base;
> +	void __iomem		*base;  /* unused if cb->read_telem is in use */
>  	struct pmt_callbacks	*cb;
>  	unsigned long		base_addr;
>  	size_t			size;
> diff --git a/drivers/platform/x86/intel/pmt/telemetry.c b/drivers/platform/x86/intel/pmt/telemetry.c
> index 953f35b6daec..5423a4dfce08 100644
> --- a/drivers/platform/x86/intel/pmt/telemetry.c
> +++ b/drivers/platform/x86/intel/pmt/telemetry.c
> @@ -329,6 +329,9 @@ int pmt_telem_read32(struct telem_endpoint *ep, u32 id, u32 *data, u32 count)
>  	if (!ep->present)
>  		return -ENODEV;
>  
> +	if (!ep->base)
> +		return -EIO;
> +
>  	offset = SAMPLE_ID_OFFSET32(id);
>  	size = ep->header.size;
>  
> -- 
> 2.43.0
>