[PATCH v2 3/6] coresight: configfs: Modify config files to allow userspace use
Mathieu Poirier
mathieu.poirier at linaro.org
Fri Jan 28 10:33:44 PST 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 at 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 at 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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