diff mbox series

[v5,26/27] cxl: add function for obtaining params from a region

Message ID 20241118164434.7551-27-alejandro.lucero-palau@amd.com
State Superseded
Headers show
Series cxl: add type2 device basic support | expand

Commit Message

Lucero Palau, Alejandro Nov. 18, 2024, 4:44 p.m. UTC 
From: Alejandro Lucero <alucerop@amd.com>

A CXL region struct contains the physical address to work with.

Add a function for given a opaque cxl region struct returns the params
to be used for mapping such memory range.

Signed-off-by: Alejandro Lucero <alucerop@amd.com>
---
 drivers/cxl/core/region.c | 16 ++++++++++++++++
 drivers/cxl/cxl.h         |  2 ++
 include/cxl/cxl.h         |  2 ++
 3 files changed, 20 insertions(+)

Comments

Zhi Wang Nov. 19, 2024, 8:40 p.m. UTC | #1 
On Mon, 18 Nov 2024 16:44:33 +0000
<alejandro.lucero-palau@amd.com> wrote:

LGTM. Reviewed-by: Zhi Wang <zhiw@nvidia.com>

> From: Alejandro Lucero <alucerop@amd.com>
> 
> A CXL region struct contains the physical address to work with.
> 
> Add a function for given a opaque cxl region struct returns the params
> to be used for mapping such memory range.
> 
> Signed-off-by: Alejandro Lucero <alucerop@amd.com>
> ---
>  drivers/cxl/core/region.c | 16 ++++++++++++++++
>  drivers/cxl/cxl.h         |  2 ++
>  include/cxl/cxl.h         |  2 ++
>  3 files changed, 20 insertions(+)
> 
> diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
> index eff3ad788077..fa44a60549f7 100644
> --- a/drivers/cxl/core/region.c
> +++ b/drivers/cxl/core/region.c
> @@ -2663,6 +2663,22 @@ static struct cxl_region *devm_cxl_add_region(struct cxl_root_decoder *cxlrd,
>  	return ERR_PTR(rc);
>  }
>  
> +int cxl_get_region_params(struct cxl_region *region, resource_size_t *start,
> +			  resource_size_t *end)
> +{
> +	if (!region)
> +		return -ENODEV;
> +
> +	if (!region->params.res)
> +		return -ENOSPC;
> +
> +	*start = region->params.res->start;
> +	*end = region->params.res->end;
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_NS_GPL(cxl_get_region_params, CXL);
> +
>  static ssize_t __create_region_show(struct cxl_root_decoder *cxlrd, char *buf)
>  {
>  	return sysfs_emit(buf, "region%u\n", atomic_read(&cxlrd->region_id));
> diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
> index ee3385db5663..7b46d313e581 100644
> --- a/drivers/cxl/cxl.h
> +++ b/drivers/cxl/cxl.h
> @@ -913,6 +913,8 @@ void cxl_coordinates_combine(struct access_coordinate *out,
>  
>  bool cxl_endpoint_decoder_reset_detected(struct cxl_port *port);
>  
> +int cxl_get_region_params(struct cxl_region *region, resource_size_t *start,
> +			  resource_size_t *end);
>  /*
>   * Unit test builds overrides this to __weak, find the 'strong' version
>   * of these symbols in tools/testing/cxl/.
> diff --git a/include/cxl/cxl.h b/include/cxl/cxl.h
> index 2a8ebabfc1dd..f14a3f292ad8 100644
> --- a/include/cxl/cxl.h
> +++ b/include/cxl/cxl.h
> @@ -77,4 +77,6 @@ struct cxl_region *cxl_create_region(struct cxl_root_decoder *cxlrd,
>  				     bool avoid_dax);
>  
>  int cxl_accel_region_detach(struct cxl_endpoint_decoder *cxled);
> +int cxl_get_region_params(struct cxl_region *region, resource_size_t *start,
> +			  resource_size_t *end);
>  #endif
Alison Schofield Nov. 21, 2024, 2:56 a.m. UTC | #2 
On Mon, Nov 18, 2024 at 04:44:33PM +0000, alejandro.lucero-palau@amd.com wrote:
> From: Alejandro Lucero <alucerop@amd.com>
> 
> A CXL region struct contains the physical address to work with.
> 
> Add a function for given a opaque cxl region struct returns the params
> to be used for mapping such memory range.

I may not be understanding what needs to be opaque here.

Why not just 'add function to get a region resource'
and then add 'cxl_get_region_resource().

Region params usually refers to the member of struct cxl_region
that is called 'params' and that includes more than the resource.

--Alison

> 
> Signed-off-by: Alejandro Lucero <alucerop@amd.com>
> ---
>  drivers/cxl/core/region.c | 16 ++++++++++++++++
>  drivers/cxl/cxl.h         |  2 ++
>  include/cxl/cxl.h         |  2 ++
>  3 files changed, 20 insertions(+)
> 
> diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
> index eff3ad788077..fa44a60549f7 100644
> --- a/drivers/cxl/core/region.c
> +++ b/drivers/cxl/core/region.c
> @@ -2663,6 +2663,22 @@ static struct cxl_region *devm_cxl_add_region(struct cxl_root_decoder *cxlrd,
>  	return ERR_PTR(rc);
>  }
>  
> +int cxl_get_region_params(struct cxl_region *region, resource_size_t *start,
> +			  resource_size_t *end)
> +{
> +	if (!region)
> +		return -ENODEV;
> +
> +	if (!region->params.res)
> +		return -ENOSPC;
> +
> +	*start = region->params.res->start;
> +	*end = region->params.res->end;
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_NS_GPL(cxl_get_region_params, CXL);
> +
>  static ssize_t __create_region_show(struct cxl_root_decoder *cxlrd, char *buf)
>  {
>  	return sysfs_emit(buf, "region%u\n", atomic_read(&cxlrd->region_id));
> diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
> index ee3385db5663..7b46d313e581 100644
> --- a/drivers/cxl/cxl.h
> +++ b/drivers/cxl/cxl.h
> @@ -913,6 +913,8 @@ void cxl_coordinates_combine(struct access_coordinate *out,
>  
>  bool cxl_endpoint_decoder_reset_detected(struct cxl_port *port);
>  
> +int cxl_get_region_params(struct cxl_region *region, resource_size_t *start,
> +			  resource_size_t *end);
>  /*
>   * Unit test builds overrides this to __weak, find the 'strong' version
>   * of these symbols in tools/testing/cxl/.
> diff --git a/include/cxl/cxl.h b/include/cxl/cxl.h
> index 2a8ebabfc1dd..f14a3f292ad8 100644
> --- a/include/cxl/cxl.h
> +++ b/include/cxl/cxl.h
> @@ -77,4 +77,6 @@ struct cxl_region *cxl_create_region(struct cxl_root_decoder *cxlrd,
>  				     bool avoid_dax);
>  
>  int cxl_accel_region_detach(struct cxl_endpoint_decoder *cxled);
> +int cxl_get_region_params(struct cxl_region *region, resource_size_t *start,
> +			  resource_size_t *end);
>  #endif
> -- 
> 2.17.1
> 
>
Dave Jiang Nov. 21, 2024, 4:31 p.m. UTC | #3 
On 11/18/24 9:44 AM, alejandro.lucero-palau@amd.com wrote:
> From: Alejandro Lucero <alucerop@amd.com>
> 
> A CXL region struct contains the physical address to work with.
> 
> Add a function for given a opaque cxl region struct returns the params
> to be used for mapping such memory range.
> 
> Signed-off-by: Alejandro Lucero <alucerop@amd.com>
> ---
>  drivers/cxl/core/region.c | 16 ++++++++++++++++
>  drivers/cxl/cxl.h         |  2 ++
>  include/cxl/cxl.h         |  2 ++
>  3 files changed, 20 insertions(+)
> 
> diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
> index eff3ad788077..fa44a60549f7 100644
> --- a/drivers/cxl/core/region.c
> +++ b/drivers/cxl/core/region.c
> @@ -2663,6 +2663,22 @@ static struct cxl_region *devm_cxl_add_region(struct cxl_root_decoder *cxlrd,
>  	return ERR_PTR(rc);
>  }
>  
> +int cxl_get_region_params(struct cxl_region *region, resource_size_t *start,
> +			  resource_size_t *end)

Maybe just pass in a 'struct range' ptr and call it cxl_get_region_range()?

DJ

> +{
> +	if (!region)
> +		return -ENODEV;
> +
> +	if (!region->params.res)
> +		return -ENOSPC;
> +
> +	*start = region->params.res->start;
> +	*end = region->params.res->end;
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_NS_GPL(cxl_get_region_params, CXL);
> +
>  static ssize_t __create_region_show(struct cxl_root_decoder *cxlrd, char *buf)
>  {
>  	return sysfs_emit(buf, "region%u\n", atomic_read(&cxlrd->region_id));
> diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
> index ee3385db5663..7b46d313e581 100644
> --- a/drivers/cxl/cxl.h
> +++ b/drivers/cxl/cxl.h
> @@ -913,6 +913,8 @@ void cxl_coordinates_combine(struct access_coordinate *out,
>  
>  bool cxl_endpoint_decoder_reset_detected(struct cxl_port *port);
>  
> +int cxl_get_region_params(struct cxl_region *region, resource_size_t *start,
> +			  resource_size_t *end);
>  /*
>   * Unit test builds overrides this to __weak, find the 'strong' version
>   * of these symbols in tools/testing/cxl/.
> diff --git a/include/cxl/cxl.h b/include/cxl/cxl.h
> index 2a8ebabfc1dd..f14a3f292ad8 100644
> --- a/include/cxl/cxl.h
> +++ b/include/cxl/cxl.h
> @@ -77,4 +77,6 @@ struct cxl_region *cxl_create_region(struct cxl_root_decoder *cxlrd,
>  				     bool avoid_dax);
>  
>  int cxl_accel_region_detach(struct cxl_endpoint_decoder *cxled);
> +int cxl_get_region_params(struct cxl_region *region, resource_size_t *start,
> +			  resource_size_t *end);
>  #endif
Alejandro Lucero Palau Nov. 27, 2024, 5:12 p.m. UTC | #4 
On 11/21/24 16:31, Dave Jiang wrote:
>
> On 11/18/24 9:44 AM, alejandro.lucero-palau@amd.com wrote:
>> From: Alejandro Lucero <alucerop@amd.com>
>>
>> A CXL region struct contains the physical address to work with.
>>
>> Add a function for given a opaque cxl region struct returns the params
>> to be used for mapping such memory range.
>>
>> Signed-off-by: Alejandro Lucero <alucerop@amd.com>
>> ---
>>   drivers/cxl/core/region.c | 16 ++++++++++++++++
>>   drivers/cxl/cxl.h         |  2 ++
>>   include/cxl/cxl.h         |  2 ++
>>   3 files changed, 20 insertions(+)
>>
>> diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
>> index eff3ad788077..fa44a60549f7 100644
>> --- a/drivers/cxl/core/region.c
>> +++ b/drivers/cxl/core/region.c
>> @@ -2663,6 +2663,22 @@ static struct cxl_region *devm_cxl_add_region(struct cxl_root_decoder *cxlrd,
>>   	return ERR_PTR(rc);
>>   }
>>   
>> +int cxl_get_region_params(struct cxl_region *region, resource_size_t *start,
>> +			  resource_size_t *end)
> Maybe just pass in a 'struct range' ptr and call it cxl_get_region_range()?


That makes sense, and that solves the problem raised by Allison.

Thanks


> DJ
>
>> +{
>> +	if (!region)
>> +		return -ENODEV;
>> +
>> +	if (!region->params.res)
>> +		return -ENOSPC;
>> +
>> +	*start = region->params.res->start;
>> +	*end = region->params.res->end;
>> +
>> +	return 0;
>> +}
>> +EXPORT_SYMBOL_NS_GPL(cxl_get_region_params, CXL);
>> +
>>   static ssize_t __create_region_show(struct cxl_root_decoder *cxlrd, char *buf)
>>   {
>>   	return sysfs_emit(buf, "region%u\n", atomic_read(&cxlrd->region_id));
>> diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
>> index ee3385db5663..7b46d313e581 100644
>> --- a/drivers/cxl/cxl.h
>> +++ b/drivers/cxl/cxl.h
>> @@ -913,6 +913,8 @@ void cxl_coordinates_combine(struct access_coordinate *out,
>>   
>>   bool cxl_endpoint_decoder_reset_detected(struct cxl_port *port);
>>   
>> +int cxl_get_region_params(struct cxl_region *region, resource_size_t *start,
>> +			  resource_size_t *end);
>>   /*
>>    * Unit test builds overrides this to __weak, find the 'strong' version
>>    * of these symbols in tools/testing/cxl/.
>> diff --git a/include/cxl/cxl.h b/include/cxl/cxl.h
>> index 2a8ebabfc1dd..f14a3f292ad8 100644
>> --- a/include/cxl/cxl.h
>> +++ b/include/cxl/cxl.h
>> @@ -77,4 +77,6 @@ struct cxl_region *cxl_create_region(struct cxl_root_decoder *cxlrd,
>>   				     bool avoid_dax);
>>   
>>   int cxl_accel_region_detach(struct cxl_endpoint_decoder *cxled);
>> +int cxl_get_region_params(struct cxl_region *region, resource_size_t *start,
>> +			  resource_size_t *end);
>>   #endif
Alejandro Lucero Palau Nov. 27, 2024, 5:18 p.m. UTC | #5 
On 11/21/24 02:56, Alison Schofield wrote:
> On Mon, Nov 18, 2024 at 04:44:33PM +0000, alejandro.lucero-palau@amd.com wrote:
>> From: Alejandro Lucero <alucerop@amd.com>
>>
>> A CXL region struct contains the physical address to work with.
>>
>> Add a function for given a opaque cxl region struct returns the params
>> to be used for mapping such memory range.
> I may not be understanding what needs to be opaque here.


The driver can not access cxl_region struct just using it in calls, what 
requires this patch as other in this patchset as an API for accel drivers.

Apologies if mentioning that here creates confusion.


> Why not just 'add function to get a region resource'
> and then add 'cxl_get_region_resource().
>
> Region params usually refers to the member of struct cxl_region
> that is called 'params' and that includes more than the resource.


I did not realize using params could be problematic, but I agree it is 
not how we should refer to what we are returning to the caller.

I think using Dave suggestion for using range instead should solve the 
problem.

Thanks


> --Alison
>
>> Signed-off-by: Alejandro Lucero <alucerop@amd.com>
>> ---
>>   drivers/cxl/core/region.c | 16 ++++++++++++++++
>>   drivers/cxl/cxl.h         |  2 ++
>>   include/cxl/cxl.h         |  2 ++
>>   3 files changed, 20 insertions(+)
>>
>> diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
>> index eff3ad788077..fa44a60549f7 100644
>> --- a/drivers/cxl/core/region.c
>> +++ b/drivers/cxl/core/region.c
>> @@ -2663,6 +2663,22 @@ static struct cxl_region *devm_cxl_add_region(struct cxl_root_decoder *cxlrd,
>>   	return ERR_PTR(rc);
>>   }
>>   
>> +int cxl_get_region_params(struct cxl_region *region, resource_size_t *start,
>> +			  resource_size_t *end)
>> +{
>> +	if (!region)
>> +		return -ENODEV;
>> +
>> +	if (!region->params.res)
>> +		return -ENOSPC;
>> +
>> +	*start = region->params.res->start;
>> +	*end = region->params.res->end;
>> +
>> +	return 0;
>> +}
>> +EXPORT_SYMBOL_NS_GPL(cxl_get_region_params, CXL);
>> +
>>   static ssize_t __create_region_show(struct cxl_root_decoder *cxlrd, char *buf)
>>   {
>>   	return sysfs_emit(buf, "region%u\n", atomic_read(&cxlrd->region_id));
>> diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
>> index ee3385db5663..7b46d313e581 100644
>> --- a/drivers/cxl/cxl.h
>> +++ b/drivers/cxl/cxl.h
>> @@ -913,6 +913,8 @@ void cxl_coordinates_combine(struct access_coordinate *out,
>>   
>>   bool cxl_endpoint_decoder_reset_detected(struct cxl_port *port);
>>   
>> +int cxl_get_region_params(struct cxl_region *region, resource_size_t *start,
>> +			  resource_size_t *end);
>>   /*
>>    * Unit test builds overrides this to __weak, find the 'strong' version
>>    * of these symbols in tools/testing/cxl/.
>> diff --git a/include/cxl/cxl.h b/include/cxl/cxl.h
>> index 2a8ebabfc1dd..f14a3f292ad8 100644
>> --- a/include/cxl/cxl.h
>> +++ b/include/cxl/cxl.h
>> @@ -77,4 +77,6 @@ struct cxl_region *cxl_create_region(struct cxl_root_decoder *cxlrd,
>>   				     bool avoid_dax);
>>   
>>   int cxl_accel_region_detach(struct cxl_endpoint_decoder *cxled);
>> +int cxl_get_region_params(struct cxl_region *region, resource_size_t *start,
>> +			  resource_size_t *end);
>>   #endif
>> -- 
>> 2.17.1
>>
>>
diff mbox series

Patch

diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index eff3ad788077..fa44a60549f7 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -2663,6 +2663,22 @@  static struct cxl_region *devm_cxl_add_region(struct cxl_root_decoder *cxlrd,
 	return ERR_PTR(rc);
 }
 
+int cxl_get_region_params(struct cxl_region *region, resource_size_t *start,
+			  resource_size_t *end)
+{
+	if (!region)
+		return -ENODEV;
+
+	if (!region->params.res)
+		return -ENOSPC;
+
+	*start = region->params.res->start;
+	*end = region->params.res->end;
+
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(cxl_get_region_params, CXL);
+
 static ssize_t __create_region_show(struct cxl_root_decoder *cxlrd, char *buf)
 {
 	return sysfs_emit(buf, "region%u\n", atomic_read(&cxlrd->region_id));
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index ee3385db5663..7b46d313e581 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -913,6 +913,8 @@  void cxl_coordinates_combine(struct access_coordinate *out,
 
 bool cxl_endpoint_decoder_reset_detected(struct cxl_port *port);
 
+int cxl_get_region_params(struct cxl_region *region, resource_size_t *start,
+			  resource_size_t *end);
 /*
  * Unit test builds overrides this to __weak, find the 'strong' version
  * of these symbols in tools/testing/cxl/.
diff --git a/include/cxl/cxl.h b/include/cxl/cxl.h
index 2a8ebabfc1dd..f14a3f292ad8 100644
--- a/include/cxl/cxl.h
+++ b/include/cxl/cxl.h
@@ -77,4 +77,6 @@  struct cxl_region *cxl_create_region(struct cxl_root_decoder *cxlrd,
 				     bool avoid_dax);
 
 int cxl_accel_region_detach(struct cxl_endpoint_decoder *cxled);
+int cxl_get_region_params(struct cxl_region *region, resource_size_t *start,
+			  resource_size_t *end);
 #endif