Re: [PATCH v2 3/6] coresight: configfs: Modify config files to allow userspace use

28 Jan 2022

On Tue, Nov 30, 2021 at 10:00:57PM +0000, Mike Leach wrote:
...
Update coresight-config.h and the coresight-config-file.c & .h
to allow use in userspace programs.
Use __KERNEL__ defines to filter out driver only structures and
elements so that user space programs can use the descriptor structures.
Abstract memory allocation in coresight-config-file.c to allow read
file functions to be run in userspace and kernel drivers.
Signed-off-by: Mike Leach mike.leach@linaro.org
.../coresight/coresight-config-file.c         | 96 +++++++++++++------
 .../coresight/coresight-config-file.h         | 33 +++++++
 .../hwtracing/coresight/coresight-config.h    | 21 ++++
 3 files changed, 122 insertions(+), 28 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-config-file.c b/drivers/hwtracing/coresight/coresight-config-file.c
index 3fd001938324..77a64b54280d 100644
--- a/drivers/hwtracing/coresight/coresight-config-file.c
+++ b/drivers/hwtracing/coresight/coresight-config-file.c
@@ -4,10 +4,58 @@

Author: Mike Leach mike.leach@linaro.org

*/
 
-#include "coresight-config.h"
 #include "coresight-config-file.h"



+/*


To allow reuse of this source in tools, define memory allocation fns according



to build environment.


*/


+#ifdef __KERNEL__
 #include "coresight-syscfg.h"
 
+static void *cscfg_calloc(size_t num, size_t size)
+{

return devm_kcalloc(cscfg_device(), num, size, GFP_KERNEL);

+}



+static char *cscfg_strdup(const char *str)
+{

return devm_kstrdup(cscfg_device(), str, GFP_KERNEL);

+}



+static void *cscfg_zalloc(size_t size)
+{

return devm_kzalloc(cscfg_device(), size, GFP_KERNEL);

+}



+#else



+#include <stddef.h>
+#include <string.h>
+#include <stdlib.h>



+static void *cscfg_calloc(size_t num, size_t size)
+{

return calloc(num, size);

+}



+static char *cscfg_strdup(const char *str)
+{

return strdup(str);

+}



+static void *cscfg_zalloc(size_t size)
+{

void *ptr = malloc(size);

if (ptr)
memset(ptr, 0, size);


return ptr;

+}



+#endif



#define cscfg_extract_u64(val64) {	\
   val64 = *(u64 *)(buffer + used); \
   used += sizeof(u64); \
@@ -80,6 +128,7 @@ static int cscfg_file_read_elem_str(const u8 *buffer, const int buflen, int *buf
   			    struct cscfg_file_elem_str *elem_str)
 {
   int used = *buf_used;

const u8 *str;

if ((buflen - used) < sizeof(u16))
   	return -EINVAL;
@@ -89,11 +138,13 @@ static int cscfg_file_read_elem_str(const u8 *buffer, const int buflen, int *buf
   if ((buflen - used) < elem_str->str_len)
   	return -EINVAL;

str = buffer + used;
/* check for 0 termination */


if (buffer[elem_str->str_len - 1] != 0)


if (str[elem_str->str_len - 1] != 0)
return -EINVAL;


elem_str->str = devm_kstrdup(cscfg_device(), (char *)buffer, GFP_KERNEL);


elem_str->str = cscfg_strdup((char *)str);
used += elem_str->str_len;

*buf_used = used;
@@ -104,14 +155,12 @@ static int cscfg_file_alloc_desc_arrays(struct cscfg_fs_load_descs *desc_arrays,
   				int nr_features)
 {
   /* arrays are 0 terminated - max of 1 config & nr_features features */

desc_arrays->config_descs = devm_kcalloc(cscfg_device(), 2,
				 sizeof(struct cscfg_config_desc *),


				 GFP_KERNEL);




desc_arrays->config_descs = cscfg_calloc(2, sizeof(struct cscfg_config_desc *));
if (!desc_arrays->config_descs)
return -ENOMEM;


desc_arrays->feat_descs = devm_kcalloc(cscfg_device(), nr_features + 1,
			       sizeof(struct cscfg_feature_desc *),


			       GFP_KERNEL);





desc_arrays->feat_descs = cscfg_calloc(nr_features + 1,
			       sizeof(struct cscfg_feature_desc *));

if (!desc_arrays->feat_descs)
return -ENOMEM;
return 0;

@@ -138,8 +187,7 @@ static int cscfg_file_read_elem_config(const u8 *buffer, const int buflen, int *
   	return 0;
 
   /* we have a config - allocate the descriptor */

config_desc = devm_kzalloc(cscfg_device(), sizeof(struct cscfg_config_desc),
		   GFP_KERNEL);




config_desc = cscfg_zalloc(sizeof(struct cscfg_config_desc));
if (!config_desc)
return -ENOMEM;

@@ -165,8 +213,7 @@ static int cscfg_file_read_elem_config(const u8 *buffer, const int buflen, int *
   /* read the array of 64bit presets if present */
   nr_preset_vals = config_desc->nr_total_params * config_desc->nr_presets;
   if (nr_preset_vals) {

presets = devm_kcalloc(cscfg_device(), nr_preset_vals,


		       sizeof(u64), GFP_KERNEL);




presets = cscfg_calloc(nr_preset_vals, sizeof(u64));

if (!presets)
	return -ENOMEM;

@@ -181,10 +228,8 @@ static int cscfg_file_read_elem_config(const u8 *buffer, const int buflen, int *
 
   /* read the array of feature names referenced by the config */
   if (config_desc->nr_feat_refs) {

config_desc->feat_ref_names = devm_kcalloc(cscfg_device(),


					   config_desc->nr_feat_refs,


					   sizeof(char *),


					   GFP_KERNEL);




config_desc->feat_ref_names = cscfg_calloc(config_desc->nr_feat_refs,


					   sizeof(char *));

if (!config_desc->feat_ref_names)
	return -ENOMEM;

@@ -262,8 +307,7 @@ static int cscfg_file_read_elem_feature(const u8 *buffer, const int buflen, int
   u32 val32;
 
   /* allocate the feature descriptor object */

feat_desc = devm_kzalloc(cscfg_device(), sizeof(struct cscfg_feature_desc),
		 GFP_KERNEL);




feat_desc = cscfg_zalloc(sizeof(struct cscfg_feature_desc));
if (!feat_desc)
return -ENOMEM;

@@ -302,10 +346,8 @@ static int cscfg_file_read_elem_feature(const u8 *buffer, const int buflen, int
   	nr_regs_bytes = ((sizeof(u32) + sizeof(u64)) * feat_desc->nr_regs);
   	if ((buflen - used) < nr_regs_bytes)
   		return -EINVAL;

feat_desc->regs_desc = devm_kcalloc(cscfg_device(),


				    feat_desc->nr_regs,


				    sizeof(struct cscfg_regval_desc),


				    GFP_KERNEL);




feat_desc->regs_desc = cscfg_calloc(feat_desc->nr_regs,


				    sizeof(struct cscfg_regval_desc));

if (!feat_desc->regs_desc)
	return -ENOMEM;

@@ -319,10 +361,8 @@ static int cscfg_file_read_elem_feature(const u8 *buffer, const int buflen, int
 
   /* parameter descriptors - string + 64 bit value */
   if (feat_desc->nr_params) {

feat_desc->params_desc = devm_kcalloc(cscfg_device(),


				      feat_desc->nr_params,


				      sizeof(struct cscfg_parameter_desc),


				      GFP_KERNEL);




feat_desc->params_desc = cscfg_calloc(feat_desc->nr_params,


				      sizeof(struct cscfg_parameter_desc));

if (!feat_desc->params_desc)
	return -ENOMEM;
for (i = 0; i < feat_desc->nr_params; i++) {

@@ -399,7 +439,7 @@ int cscfg_file_read_buffer(const u8 *buffer, const int buflen,
   	if (err)
   		return err;
   }

return used;


return 0;

}
 
 int cscfg_file_read_buffer_first_name(const u8 *buffer, const int buflen,
diff --git a/drivers/hwtracing/coresight/coresight-config-file.h b/drivers/hwtracing/coresight/coresight-config-file.h
index 03899f7d94c9..04c365e5109b 100644
--- a/drivers/hwtracing/coresight/coresight-config-file.h
+++ b/drivers/hwtracing/coresight/coresight-config-file.h
@@ -7,6 +7,39 @@
 #ifndef _CORESIGHT_CORESIGHT_CONFIG_FILE_H
 #define _CORESIGHT_CORESIGHT_CONFIG_FILE_H
 
+#include <linux/types.h>



+#ifndef __KERNEL__
+/*


allow the user space programs to include the coresight config headers



to use the _desc structures, and reuse the read code


*/

+#ifndef u8
+typedef __u8 u8;
+typedef __u16 u16;
+typedef __u32 u32;
+typedef __u64 u64;
+#endif



+/* ARRAY SIZE is useful too */
+#ifndef ARRAY_SIZE
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+#endif



+/* define EINVAL for user space */
+#ifndef EINVAL
+#define EINVAL 22
+#endif



+#ifndef ENOMEM
+#define ENOMEM 12
+#endif



+#endif



+#include "coresight-config.h"




/*

Structures to represent configuration descriptors in a memory buffer
to serialise to and from files

diff --git a/drivers/hwtracing/coresight/coresight-config.h b/drivers/hwtracing/coresight/coresight-config.h
index 770986316bc2..2136393df710 100644
--- a/drivers/hwtracing/coresight/coresight-config.h
+++ b/drivers/hwtracing/coresight/coresight-config.h
@@ -7,7 +7,14 @@
 #ifndef _CORESIGHT_CORESIGHT_CONFIG_H
 #define _CORESIGHT_CORESIGHT_CONFIG_H
 
+/*


Filter out kernel only portions of the file to allow user space programs



to use the descriptor definitions.


*/

+#ifdef __KERNEL__
 #include <linux/coresight.h>
+#endif



#include <linux/types.h>
 
 /* CoreSight Configuration Management - component and system wide configuration */
@@ -103,14 +110,18 @@ struct cscfg_regval_desc {
 struct cscfg_feature_desc {
   const char *name;
   const char *description;
+#ifdef __KERNEL__
   struct list_head item;
+#endif
   u32 match_flags;
   int nr_params;
   struct cscfg_parameter_desc *params_desc;
   int nr_regs;
   struct cscfg_regval_desc *regs_desc;
+#ifdef __KERNEL__
   void *load_owner;
   struct config_group *fs_group;
+#endif
 };
That will quickly become a maintenance nightmare.  I suggest the following:
struct cscfg_feature_desc {
    struct list_head item;
    void *load_owner;
    struct config_group *fs_group;
        struct cscfg_feature_udesc *udesc;
};
struct cscfg_feature_udesc {
        u32 version;
    const char *name;
    const char *description;
    u32 match_flags;
    int nr_params;
    struct cscfg_parameter_desc *params_desc;
    int nr_regs;
    struct cscfg_regval_desc *regs_desc;
};
Structure cscfg_feature_udesc should likely be under include/uapi/linux/coresight-config.h
...
/**
@@ -138,16 +149,20 @@ struct cscfg_feature_desc {
 struct cscfg_config_desc {
   const char *name;
   const char *description;
+#ifdef __KERNEL__
   struct list_head item;
+#endif
   int nr_feat_refs;
   const char **feat_ref_names;
   int nr_presets;
   int nr_total_params;
   const u64 *presets; /* nr_presets * nr_total_params */
+#ifdef __KERNEL__
   struct dev_ext_attribute *event_ea;
   atomic_t active_cnt;
   void *load_owner;
   struct config_group *fs_group;
+#endif
 };
 
 /**
@@ -162,11 +177,16 @@ struct cscfg_config_desc {

@feat_descs:		array of feature descriptor pointers.

*/
 struct cscfg_fs_load_descs {
+#ifdef __KERNEL__
   void *owner_info;
+#endif
   struct cscfg_config_desc **config_descs;
   struct cscfg_feature_desc **feat_descs;
 };
Same comment as above.
...
+/* remainder of header is used by the kernel drivers only */
+#ifdef __KERNEL__



/**

config register instance - part of a loaded feature.
                       maps register values to csdev driver structures



@@ -274,4 +294,5 @@ void cscfg_csdev_disable_config(struct cscfg_config_csdev *config_csdev);
 /* reset a feature to default values */
 void cscfg_reset_feat(struct cscfg_feature_csdev *feat_csdev);
 
+#endif /* __KERNEL__ */
#endif /* _CORESIGHT_CORESIGHT_CONFIG_H */
2.17.1

    

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Re: [PATCH v2 3/6] coresight: configfs: Modify config files to allow userspace use

Signed-off-by: Mike Leach mike.leach@linaro.org

#endif /* _CORESIGHT_CORESIGHT_CONFIG_H */