| Message ID | 20211130220100.25888-7-mike.leach@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | coresight: syscfg: Extend configfs for config load | expand |
Hi Mike, On Tue, Nov 30, 2021 at 10:01:00PM +0000, Mike Leach wrote: > Add documentation covering the configfs updates that allow > binary configuration files to be loaded and unloaded via configfs, > along with the demonstration programs in samples. > > Signed-off-by: Mike Leach <mike.leach@linaro.org> > --- > .../trace/coresight/coresight-config.rst | 151 +++++++++++++++++- > 1 file changed, 145 insertions(+), 6 deletions(-) > > diff --git a/Documentation/trace/coresight/coresight-config.rst b/Documentation/trace/coresight/coresight-config.rst > index 6d5ffa6f7347..f11def230fab 100644 > --- a/Documentation/trace/coresight/coresight-config.rst > +++ b/Documentation/trace/coresight/coresight-config.rst > @@ -152,7 +152,7 @@ follows:: > > $ cd configurations/ > $ ls > - autofdo > + autofdo last_load_status load unload > $ cd autofdo/ > $ ls > description feature_refs preset1 preset3 preset5 preset7 preset9 > @@ -278,9 +278,19 @@ Creating and Loading Custom Configurations > ========================================== > > Custom configurations and / or features can be dynamically loaded into the > -system by using a loadable module. > +system by using a loadable module, or by loading a binary configuration > +file in configfs. > + > +Loaded configurations can use previously loaded features. The system will > +ensure that it is not possible to unload a feature that is currently in > +use, by enforcing the unload order as the strict reverse of the load order. > + > +An example of a custom configuration module, and generators for binary > +configuration files are found in './samples/coresight'. > > -An example of a custom configuration is found in ./samples/coresight. > + > +Using a Loadable Module > +----------------------- > > This creates a new configuration that uses the existing built in > strobing feature, but provides a different set of presets. > @@ -289,6 +299,135 @@ When the module is loaded, then the configuration appears in the configfs > file system and is selectable in the same way as the built in configuration > described above. > > -Configurations can use previously loaded features. The system will ensure > -that it is not possible to unload a feature that is currently in use, by > -enforcing the unload order as the strict reverse of the load order. > +The file 'coresight-cfg-sample.c' contains the configuration and module > +initialisation code needed to create the loadable module. > + > +This will be built alongside the kernel modules if select in KConfig. > + > + > +Using a Binary Configuration File > +--------------------------------- > + > +Building the samples creates the 'coresight-cfg-filegen' program that will > +generate a configuration binary 'example1.cscfg' that can be loaded into the > +system using configfs. The configuration declared in the source file > +'coresight-cfg-filegen.c' is named 'autofdo3' - the name that will be used > +once loaded. > + > +The source files 'coresight-cfg-bufw.h' and 'coresight-cfg-bufw.c' provide a > +standard function to convert a configuration declared in 'C' into the correct > +binary buffer format. These files can be re-used to create new custom > +configurations. > + > +The program 'coresight-cfg-file-read' can read back and print a configuration > +binary. This is built using the reader from the driver code. > + > +There are additional attributes in the configurations directory - load, unload > +and last_load_status that can be used to load and unload configuration > +binary files. To load, 'cat' the binary config into the load attribute:: > + > + $ ls /config/cs-syscfg/configurations/ > + autofdo last_load_status load unload > + $ cat example1.cscfg > /config/cs-syscfg/configurations/load > + $ ls /config/cs-syscfg/configurations/ > + autofdo autofdo3 last_load_status load unload > + $ cat /config/cs-syscfg/configurations/last_load_status > + OK: configuration file loaded (autofdo3). > + > +To unload, use the same file in the unload attribute:: > + > + $ cat example1.cscfg > /config/cs-syscfg/configurations/unload > + $ cat /config/cs-syscfg/configurations/last_load_status > + OK: configuration file unloaded (autofdo3). > + ls /config/cs-syscfg/configurations/ > + autofdo last_load_status load unload > + > +The generator and reader programs can also be built directly, separately from > +the kernel build by using the 'Makefile.host' file. This allows native binaries > +to be created on the host machine rather than cross compiled version for the > +target. > + > + > +Binary Configuration File Format > +-------------------------------- > + > +The file format is defined in the source file **coresight-config-file.h** > + > +The source reader and generator examples produce a binary of this format. > + > +This arrangement is reproduced below:- > + > +Overall File structure > +~~~~~~~~~~~~~~~~~~~~~~ > + > +:: > + > + [cscfg_file_header] // Mandatory > + [CONFIG_ELEM] // Optional - one per file, if present, first element in file. > + [FEATURE_ELEM]* // Optional - multiple, defined by cscfg_file_header.nr_features > + > +File is invalid if both [CONFIG_ELEM] and [FEATURE_ELEM] are omitted. > + > +A file that contains only [FEATURE_ELEM] may be loaded, and the features used > +by subsequently loaded files with [CONFIG_ELEM] elements. > + > +Where [CONFIG_ELEM] is present, then **cscfg_file_header.nr_features** and > +**CONFIG_ELEM.nr_feat_refs** must have the same value. > + > +CONFIG_ELEM element > +~~~~~~~~~~~~~~~~~~~ > + > +:: > + > + [cscfg_file_elem_header] // header length value to end of feature strings. > + [cscfg_file_elem_str] // name of the configuration. > + [cscfg_file_elem_str] // description of configuration. > + [u16 value](nr_presets) // number of defined presets. > + [u32 value](nr_total_params) // total parameters defined by all used features. > + [u16 value](nr_feat_refs) // number of features referenced by the configuration > + [u64 values] * (nr_presets * nr_total_params) // the preset values. > + [cscfg_file_elem_str] * (nr_feat_refs) // the features used in the configurations. There seems to be a discrepency between the above format and the afdo3 structure definition in sample file coresight-cfg-filegen.c. More comments to come... Thanks, Mathieu > + > +FEATURE_ELEM element > +~~~~~~~~~~~~~~~~~~~~ > + > +:: > + > + [cscfg_file_elem_header] // header length is total bytes to end of param structures. > + [cscfg_file_elem_str] // feature name. > + [cscfg_file_elem_str] // feature description. > + [u32 value](match_flags) // flags to associate the feature with a device. > + [u16 value](nr_regs) // number of registers. > + [u16 value](nr_params) // number of parameters. > + [cscfg_regval_desc struct] * (nr_regs) // register definitions > + [PARAM_ELEM] * (nr_params) // parameters definitions > + > +PARAM_ELEM element > +~~~~~~~~~~~~~~~~~~ > + > +:: > + > + [cscfg_file_elem_str] // parameter name. > + [u64 value](param_value] // initial value. > + > +Additional definitions. > +~~~~~~~~~~~~~~~~~~~~~~~ > + > +The following structures are defined in **coresight-config-file.h** > + > + * **struct cscfg_file_header** : This structure contains an initial magic number, the total > + length of the file, and the number of features in the file. > + * **struct cscfg_file_elem_header**: This defines the total length and type of a CONFIG_ELEM > + or a FEATURE_ELEM. > + * **struct cscfg_file_elem_str**: This defines a string and its length. > + > +The magic number in cscfg_file_header is defined as two bitfields:: > + > + [31:8] Fixed magic number to identify file type. > + [7:0] Current file format version. > + > +The following defines determine the maximum overall file size and maximum individual > +string size:: > + > + CSCFG_FILE_MAXSIZE // maximum overall file size. > + CSCFG_FILE_STR_MAXSIZE // maximum individual string size. > -- > 2.17.1 >
[...] > > + > > +CONFIG_ELEM element > > +~~~~~~~~~~~~~~~~~~~ > > + > > +:: > > + > > + [cscfg_file_elem_header] // header length value to end of feature strings. > > + [cscfg_file_elem_str] // name of the configuration. > > + [cscfg_file_elem_str] // description of configuration. > > + [u16 value](nr_presets) // number of defined presets. > > + [u32 value](nr_total_params) // total parameters defined by all used features. > > + [u16 value](nr_feat_refs) // number of features referenced by the configuration > > + [u64 values] * (nr_presets * nr_total_params) // the preset values. > > + [cscfg_file_elem_str] * (nr_feat_refs) // the features used in the configurations. > > There seems to be a discrepency between the above format and the afdo3 structure > definition in sample file coresight-cfg-filegen.c. > Void that comment - the above and the struct cscfg_config_desc don't have a 1:1 mapping. > More comments to come... > > Thanks, > Mathieu > > > + > > +FEATURE_ELEM element > > +~~~~~~~~~~~~~~~~~~~~ > > + > > +:: > > + > > + [cscfg_file_elem_header] // header length is total bytes to end of param structures. > > + [cscfg_file_elem_str] // feature name. > > + [cscfg_file_elem_str] // feature description. > > + [u32 value](match_flags) // flags to associate the feature with a device. > > + [u16 value](nr_regs) // number of registers. > > + [u16 value](nr_params) // number of parameters. > > + [cscfg_regval_desc struct] * (nr_regs) // register definitions > > + [PARAM_ELEM] * (nr_params) // parameters definitions > > + > > +PARAM_ELEM element > > +~~~~~~~~~~~~~~~~~~ > > + > > +:: > > + > > + [cscfg_file_elem_str] // parameter name. > > + [u64 value](param_value] // initial value. > > + > > +Additional definitions. > > +~~~~~~~~~~~~~~~~~~~~~~~ > > + > > +The following structures are defined in **coresight-config-file.h** > > + > > + * **struct cscfg_file_header** : This structure contains an initial magic number, the total > > + length of the file, and the number of features in the file. > > + * **struct cscfg_file_elem_header**: This defines the total length and type of a CONFIG_ELEM > > + or a FEATURE_ELEM. > > + * **struct cscfg_file_elem_str**: This defines a string and its length. > > + > > +The magic number in cscfg_file_header is defined as two bitfields:: > > + > > + [31:8] Fixed magic number to identify file type. > > + [7:0] Current file format version. > > + > > +The following defines determine the maximum overall file size and maximum individual > > +string size:: > > + > > + CSCFG_FILE_MAXSIZE // maximum overall file size. > > + CSCFG_FILE_STR_MAXSIZE // maximum individual string size. > > -- > > 2.17.1 > >
More comments... On Tue, Nov 30, 2021 at 10:01:00PM +0000, Mike Leach wrote: > Add documentation covering the configfs updates that allow > binary configuration files to be loaded and unloaded via configfs, > along with the demonstration programs in samples. > > Signed-off-by: Mike Leach <mike.leach@linaro.org> > --- > .../trace/coresight/coresight-config.rst | 151 +++++++++++++++++- > 1 file changed, 145 insertions(+), 6 deletions(-) > > diff --git a/Documentation/trace/coresight/coresight-config.rst b/Documentation/trace/coresight/coresight-config.rst > index 6d5ffa6f7347..f11def230fab 100644 > --- a/Documentation/trace/coresight/coresight-config.rst > +++ b/Documentation/trace/coresight/coresight-config.rst > @@ -152,7 +152,7 @@ follows:: > > $ cd configurations/ > $ ls > - autofdo > + autofdo last_load_status load unload > $ cd autofdo/ > $ ls > description feature_refs preset1 preset3 preset5 preset7 preset9 > @@ -278,9 +278,19 @@ Creating and Loading Custom Configurations > ========================================== > > Custom configurations and / or features can be dynamically loaded into the > -system by using a loadable module. > +system by using a loadable module, or by loading a binary configuration > +file in configfs. > + > +Loaded configurations can use previously loaded features. The system will > +ensure that it is not possible to unload a feature that is currently in > +use, by enforcing the unload order as the strict reverse of the load order. > + > +An example of a custom configuration module, and generators for binary > +configuration files are found in './samples/coresight'. > > -An example of a custom configuration is found in ./samples/coresight. > + > +Using a Loadable Module > +----------------------- > > This creates a new configuration that uses the existing built in > strobing feature, but provides a different set of presets. > @@ -289,6 +299,135 @@ When the module is loaded, then the configuration appears in the configfs > file system and is selectable in the same way as the built in configuration > described above. > > -Configurations can use previously loaded features. The system will ensure > -that it is not possible to unload a feature that is currently in use, by > -enforcing the unload order as the strict reverse of the load order. > +The file 'coresight-cfg-sample.c' contains the configuration and module > +initialisation code needed to create the loadable module. > + > +This will be built alongside the kernel modules if select in KConfig. > + > + > +Using a Binary Configuration File > +--------------------------------- > + > +Building the samples creates the 'coresight-cfg-filegen' program that will > +generate a configuration binary 'example1.cscfg' that can be loaded into the > +system using configfs. The configuration declared in the source file > +'coresight-cfg-filegen.c' is named 'autofdo3' - the name that will be used > +once loaded. > + > +The source files 'coresight-cfg-bufw.h' and 'coresight-cfg-bufw.c' provide a > +standard function to convert a configuration declared in 'C' into the correct > +binary buffer format. These files can be re-used to create new custom > +configurations. > + > +The program 'coresight-cfg-file-read' can read back and print a configuration > +binary. This is built using the reader from the driver code. > + > +There are additional attributes in the configurations directory - load, unload > +and last_load_status that can be used to load and unload configuration > +binary files. To load, 'cat' the binary config into the load attribute:: > + > + $ ls /config/cs-syscfg/configurations/ > + autofdo last_load_status load unload > + $ cat example1.cscfg > /config/cs-syscfg/configurations/load > + $ ls /config/cs-syscfg/configurations/ > + autofdo autofdo3 last_load_status load unload > + $ cat /config/cs-syscfg/configurations/last_load_status > + OK: configuration file loaded (autofdo3). > + > +To unload, use the same file in the unload attribute:: > + > + $ cat example1.cscfg > /config/cs-syscfg/configurations/unload > + $ cat /config/cs-syscfg/configurations/last_load_status > + OK: configuration file unloaded (autofdo3). > + ls /config/cs-syscfg/configurations/ > + autofdo last_load_status load unload I'm not certain that "last_load_status" is needed. To me seeing the name of a newly added configuration should be enough to confirm a successful status. The same applies to unload. Thanks, Mathieu > + > +The generator and reader programs can also be built directly, separately from > +the kernel build by using the 'Makefile.host' file. This allows native binaries > +to be created on the host machine rather than cross compiled version for the > +target. > + > + > +Binary Configuration File Format > +-------------------------------- > + > +The file format is defined in the source file **coresight-config-file.h** > + > +The source reader and generator examples produce a binary of this format. > + > +This arrangement is reproduced below:- > + > +Overall File structure > +~~~~~~~~~~~~~~~~~~~~~~ > + > +:: > + > + [cscfg_file_header] // Mandatory > + [CONFIG_ELEM] // Optional - one per file, if present, first element in file. > + [FEATURE_ELEM]* // Optional - multiple, defined by cscfg_file_header.nr_features > + > +File is invalid if both [CONFIG_ELEM] and [FEATURE_ELEM] are omitted. > + > +A file that contains only [FEATURE_ELEM] may be loaded, and the features used > +by subsequently loaded files with [CONFIG_ELEM] elements. > + > +Where [CONFIG_ELEM] is present, then **cscfg_file_header.nr_features** and > +**CONFIG_ELEM.nr_feat_refs** must have the same value. > + > +CONFIG_ELEM element > +~~~~~~~~~~~~~~~~~~~ > + > +:: > + > + [cscfg_file_elem_header] // header length value to end of feature strings. > + [cscfg_file_elem_str] // name of the configuration. > + [cscfg_file_elem_str] // description of configuration. > + [u16 value](nr_presets) // number of defined presets. > + [u32 value](nr_total_params) // total parameters defined by all used features. > + [u16 value](nr_feat_refs) // number of features referenced by the configuration > + [u64 values] * (nr_presets * nr_total_params) // the preset values. > + [cscfg_file_elem_str] * (nr_feat_refs) // the features used in the configurations. > + > +FEATURE_ELEM element > +~~~~~~~~~~~~~~~~~~~~ > + > +:: > + > + [cscfg_file_elem_header] // header length is total bytes to end of param structures. > + [cscfg_file_elem_str] // feature name. > + [cscfg_file_elem_str] // feature description. > + [u32 value](match_flags) // flags to associate the feature with a device. > + [u16 value](nr_regs) // number of registers. > + [u16 value](nr_params) // number of parameters. > + [cscfg_regval_desc struct] * (nr_regs) // register definitions > + [PARAM_ELEM] * (nr_params) // parameters definitions > + > +PARAM_ELEM element > +~~~~~~~~~~~~~~~~~~ > + > +:: > + > + [cscfg_file_elem_str] // parameter name. > + [u64 value](param_value] // initial value. > + > +Additional definitions. > +~~~~~~~~~~~~~~~~~~~~~~~ > + > +The following structures are defined in **coresight-config-file.h** > + > + * **struct cscfg_file_header** : This structure contains an initial magic number, the total > + length of the file, and the number of features in the file. > + * **struct cscfg_file_elem_header**: This defines the total length and type of a CONFIG_ELEM > + or a FEATURE_ELEM. > + * **struct cscfg_file_elem_str**: This defines a string and its length. > + > +The magic number in cscfg_file_header is defined as two bitfields:: > + > + [31:8] Fixed magic number to identify file type. > + [7:0] Current file format version. > + > +The following defines determine the maximum overall file size and maximum individual > +string size:: > + > + CSCFG_FILE_MAXSIZE // maximum overall file size. > + CSCFG_FILE_STR_MAXSIZE // maximum individual string size. > -- > 2.17.1 >
Hi Mathieu, On Thu, 13 Jan 2022 at 18:16, Mathieu Poirier <mathieu.poirier@linaro.org> wrote: > > More comments... > > On Tue, Nov 30, 2021 at 10:01:00PM +0000, Mike Leach wrote: > > Add documentation covering the configfs updates that allow > > binary configuration files to be loaded and unloaded via configfs, > > along with the demonstration programs in samples. > > > > Signed-off-by: Mike Leach <mike.leach@linaro.org> > > --- > > .../trace/coresight/coresight-config.rst | 151 +++++++++++++++++- > > 1 file changed, 145 insertions(+), 6 deletions(-) > > > > diff --git a/Documentation/trace/coresight/coresight-config.rst b/Documentation/trace/coresight/coresight-config.rst > > index 6d5ffa6f7347..f11def230fab 100644 > > --- a/Documentation/trace/coresight/coresight-config.rst > > +++ b/Documentation/trace/coresight/coresight-config.rst > > @@ -152,7 +152,7 @@ follows:: > > > > $ cd configurations/ > > $ ls > > - autofdo > > + autofdo last_load_status load unload > > $ cd autofdo/ > > $ ls > > description feature_refs preset1 preset3 preset5 preset7 preset9 > > @@ -278,9 +278,19 @@ Creating and Loading Custom Configurations > > ========================================== > > > > Custom configurations and / or features can be dynamically loaded into the > > -system by using a loadable module. > > +system by using a loadable module, or by loading a binary configuration > > +file in configfs. > > + > > +Loaded configurations can use previously loaded features. The system will > > +ensure that it is not possible to unload a feature that is currently in > > +use, by enforcing the unload order as the strict reverse of the load order. > > + > > +An example of a custom configuration module, and generators for binary > > +configuration files are found in './samples/coresight'. > > > > -An example of a custom configuration is found in ./samples/coresight. > > + > > +Using a Loadable Module > > +----------------------- > > > > This creates a new configuration that uses the existing built in > > strobing feature, but provides a different set of presets. > > @@ -289,6 +299,135 @@ When the module is loaded, then the configuration appears in the configfs > > file system and is selectable in the same way as the built in configuration > > described above. > > > > -Configurations can use previously loaded features. The system will ensure > > -that it is not possible to unload a feature that is currently in use, by > > -enforcing the unload order as the strict reverse of the load order. > > +The file 'coresight-cfg-sample.c' contains the configuration and module > > +initialisation code needed to create the loadable module. > > + > > +This will be built alongside the kernel modules if select in KConfig. > > + > > + > > +Using a Binary Configuration File > > +--------------------------------- > > + > > +Building the samples creates the 'coresight-cfg-filegen' program that will > > +generate a configuration binary 'example1.cscfg' that can be loaded into the > > +system using configfs. The configuration declared in the source file > > +'coresight-cfg-filegen.c' is named 'autofdo3' - the name that will be used > > +once loaded. > > + > > +The source files 'coresight-cfg-bufw.h' and 'coresight-cfg-bufw.c' provide a > > +standard function to convert a configuration declared in 'C' into the correct > > +binary buffer format. These files can be re-used to create new custom > > +configurations. > > + > > +The program 'coresight-cfg-file-read' can read back and print a configuration > > +binary. This is built using the reader from the driver code. > > + > > +There are additional attributes in the configurations directory - load, unload > > +and last_load_status that can be used to load and unload configuration > > +binary files. To load, 'cat' the binary config into the load attribute:: > > + > > + $ ls /config/cs-syscfg/configurations/ > > + autofdo last_load_status load unload > > + $ cat example1.cscfg > /config/cs-syscfg/configurations/load > > + $ ls /config/cs-syscfg/configurations/ > > + autofdo autofdo3 last_load_status load unload > > + $ cat /config/cs-syscfg/configurations/last_load_status > > + OK: configuration file loaded (autofdo3). > > + > > +To unload, use the same file in the unload attribute:: > > + > > + $ cat example1.cscfg > /config/cs-syscfg/configurations/unload > > + $ cat /config/cs-syscfg/configurations/last_load_status > > + OK: configuration file unloaded (autofdo3). > > + ls /config/cs-syscfg/configurations/ > > + autofdo last_load_status load unload > > I'm not certain that "last_load_status" is needed. To me seeing the name of a > newly added configuration should be enough to confirm a successful status. The > same applies to unload. > Again - this makes more sense after the next ETM patchset that uses resource management - this status is more useful when features or configurations fail to load - as this can be due to insufficient resources on the system. When we have portable binary configuration files, loading via configfs, then this information is important to users. Thanks Mike > Thanks, > Mathieu > > > + > > +The generator and reader programs can also be built directly, separately from > > +the kernel build by using the 'Makefile.host' file. This allows native binaries > > +to be created on the host machine rather than cross compiled version for the > > +target. > > + > > + > > +Binary Configuration File Format > > +-------------------------------- > > + > > +The file format is defined in the source file **coresight-config-file.h** > > + > > +The source reader and generator examples produce a binary of this format. > > + > > +This arrangement is reproduced below:- > > + > > +Overall File structure > > +~~~~~~~~~~~~~~~~~~~~~~ > > + > > +:: > > + > > + [cscfg_file_header] // Mandatory > > + [CONFIG_ELEM] // Optional - one per file, if present, first element in file. > > + [FEATURE_ELEM]* // Optional - multiple, defined by cscfg_file_header.nr_features > > + > > +File is invalid if both [CONFIG_ELEM] and [FEATURE_ELEM] are omitted. > > + > > +A file that contains only [FEATURE_ELEM] may be loaded, and the features used > > +by subsequently loaded files with [CONFIG_ELEM] elements. > > + > > +Where [CONFIG_ELEM] is present, then **cscfg_file_header.nr_features** and > > +**CONFIG_ELEM.nr_feat_refs** must have the same value. > > + > > +CONFIG_ELEM element > > +~~~~~~~~~~~~~~~~~~~ > > + > > +:: > > + > > + [cscfg_file_elem_header] // header length value to end of feature strings. > > + [cscfg_file_elem_str] // name of the configuration. > > + [cscfg_file_elem_str] // description of configuration. > > + [u16 value](nr_presets) // number of defined presets. > > + [u32 value](nr_total_params) // total parameters defined by all used features. > > + [u16 value](nr_feat_refs) // number of features referenced by the configuration > > + [u64 values] * (nr_presets * nr_total_params) // the preset values. > > + [cscfg_file_elem_str] * (nr_feat_refs) // the features used in the configurations. > > + > > +FEATURE_ELEM element > > +~~~~~~~~~~~~~~~~~~~~ > > + > > +:: > > + > > + [cscfg_file_elem_header] // header length is total bytes to end of param structures. > > + [cscfg_file_elem_str] // feature name. > > + [cscfg_file_elem_str] // feature description. > > + [u32 value](match_flags) // flags to associate the feature with a device. > > + [u16 value](nr_regs) // number of registers. > > + [u16 value](nr_params) // number of parameters. > > + [cscfg_regval_desc struct] * (nr_regs) // register definitions > > + [PARAM_ELEM] * (nr_params) // parameters definitions > > + > > +PARAM_ELEM element > > +~~~~~~~~~~~~~~~~~~ > > + > > +:: > > + > > + [cscfg_file_elem_str] // parameter name. > > + [u64 value](param_value] // initial value. > > + > > +Additional definitions. > > +~~~~~~~~~~~~~~~~~~~~~~~ > > + > > +The following structures are defined in **coresight-config-file.h** > > + > > + * **struct cscfg_file_header** : This structure contains an initial magic number, the total > > + length of the file, and the number of features in the file. > > + * **struct cscfg_file_elem_header**: This defines the total length and type of a CONFIG_ELEM > > + or a FEATURE_ELEM. > > + * **struct cscfg_file_elem_str**: This defines a string and its length. > > + > > +The magic number in cscfg_file_header is defined as two bitfields:: > > + > > + [31:8] Fixed magic number to identify file type. > > + [7:0] Current file format version. > > + > > +The following defines determine the maximum overall file size and maximum individual > > +string size:: > > + > > + CSCFG_FILE_MAXSIZE // maximum overall file size. > > + CSCFG_FILE_STR_MAXSIZE // maximum individual string size. > > -- > > 2.17.1 > >
diff --git a/Documentation/trace/coresight/coresight-config.rst b/Documentation/trace/coresight/coresight-config.rst index 6d5ffa6f7347..f11def230fab 100644 --- a/Documentation/trace/coresight/coresight-config.rst +++ b/Documentation/trace/coresight/coresight-config.rst @@ -152,7 +152,7 @@ follows:: $ cd configurations/ $ ls - autofdo + autofdo last_load_status load unload $ cd autofdo/ $ ls description feature_refs preset1 preset3 preset5 preset7 preset9 @@ -278,9 +278,19 @@ Creating and Loading Custom Configurations ========================================== Custom configurations and / or features can be dynamically loaded into the -system by using a loadable module. +system by using a loadable module, or by loading a binary configuration +file in configfs. + +Loaded configurations can use previously loaded features. The system will +ensure that it is not possible to unload a feature that is currently in +use, by enforcing the unload order as the strict reverse of the load order. + +An example of a custom configuration module, and generators for binary +configuration files are found in './samples/coresight'. -An example of a custom configuration is found in ./samples/coresight. + +Using a Loadable Module +----------------------- This creates a new configuration that uses the existing built in strobing feature, but provides a different set of presets. @@ -289,6 +299,135 @@ When the module is loaded, then the configuration appears in the configfs file system and is selectable in the same way as the built in configuration described above. -Configurations can use previously loaded features. The system will ensure -that it is not possible to unload a feature that is currently in use, by -enforcing the unload order as the strict reverse of the load order. +The file 'coresight-cfg-sample.c' contains the configuration and module +initialisation code needed to create the loadable module. + +This will be built alongside the kernel modules if select in KConfig. + + +Using a Binary Configuration File +--------------------------------- + +Building the samples creates the 'coresight-cfg-filegen' program that will +generate a configuration binary 'example1.cscfg' that can be loaded into the +system using configfs. The configuration declared in the source file +'coresight-cfg-filegen.c' is named 'autofdo3' - the name that will be used +once loaded. + +The source files 'coresight-cfg-bufw.h' and 'coresight-cfg-bufw.c' provide a +standard function to convert a configuration declared in 'C' into the correct +binary buffer format. These files can be re-used to create new custom +configurations. + +The program 'coresight-cfg-file-read' can read back and print a configuration +binary. This is built using the reader from the driver code. + +There are additional attributes in the configurations directory - load, unload +and last_load_status that can be used to load and unload configuration +binary files. To load, 'cat' the binary config into the load attribute:: + + $ ls /config/cs-syscfg/configurations/ + autofdo last_load_status load unload + $ cat example1.cscfg > /config/cs-syscfg/configurations/load + $ ls /config/cs-syscfg/configurations/ + autofdo autofdo3 last_load_status load unload + $ cat /config/cs-syscfg/configurations/last_load_status + OK: configuration file loaded (autofdo3). + +To unload, use the same file in the unload attribute:: + + $ cat example1.cscfg > /config/cs-syscfg/configurations/unload + $ cat /config/cs-syscfg/configurations/last_load_status + OK: configuration file unloaded (autofdo3). + ls /config/cs-syscfg/configurations/ + autofdo last_load_status load unload + +The generator and reader programs can also be built directly, separately from +the kernel build by using the 'Makefile.host' file. This allows native binaries +to be created on the host machine rather than cross compiled version for the +target. + + +Binary Configuration File Format +-------------------------------- + +The file format is defined in the source file **coresight-config-file.h** + +The source reader and generator examples produce a binary of this format. + +This arrangement is reproduced below:- + +Overall File structure +~~~~~~~~~~~~~~~~~~~~~~ + +:: + + [cscfg_file_header] // Mandatory + [CONFIG_ELEM] // Optional - one per file, if present, first element in file. + [FEATURE_ELEM]* // Optional - multiple, defined by cscfg_file_header.nr_features + +File is invalid if both [CONFIG_ELEM] and [FEATURE_ELEM] are omitted. + +A file that contains only [FEATURE_ELEM] may be loaded, and the features used +by subsequently loaded files with [CONFIG_ELEM] elements. + +Where [CONFIG_ELEM] is present, then **cscfg_file_header.nr_features** and +**CONFIG_ELEM.nr_feat_refs** must have the same value. + +CONFIG_ELEM element +~~~~~~~~~~~~~~~~~~~ + +:: + + [cscfg_file_elem_header] // header length value to end of feature strings. + [cscfg_file_elem_str] // name of the configuration. + [cscfg_file_elem_str] // description of configuration. + [u16 value](nr_presets) // number of defined presets. + [u32 value](nr_total_params) // total parameters defined by all used features. + [u16 value](nr_feat_refs) // number of features referenced by the configuration + [u64 values] * (nr_presets * nr_total_params) // the preset values. + [cscfg_file_elem_str] * (nr_feat_refs) // the features used in the configurations. + +FEATURE_ELEM element +~~~~~~~~~~~~~~~~~~~~ + +:: + + [cscfg_file_elem_header] // header length is total bytes to end of param structures. + [cscfg_file_elem_str] // feature name. + [cscfg_file_elem_str] // feature description. + [u32 value](match_flags) // flags to associate the feature with a device. + [u16 value](nr_regs) // number of registers. + [u16 value](nr_params) // number of parameters. + [cscfg_regval_desc struct] * (nr_regs) // register definitions + [PARAM_ELEM] * (nr_params) // parameters definitions + +PARAM_ELEM element +~~~~~~~~~~~~~~~~~~ + +:: + + [cscfg_file_elem_str] // parameter name. + [u64 value](param_value] // initial value. + +Additional definitions. +~~~~~~~~~~~~~~~~~~~~~~~ + +The following structures are defined in **coresight-config-file.h** + + * **struct cscfg_file_header** : This structure contains an initial magic number, the total + length of the file, and the number of features in the file. + * **struct cscfg_file_elem_header**: This defines the total length and type of a CONFIG_ELEM + or a FEATURE_ELEM. + * **struct cscfg_file_elem_str**: This defines a string and its length. + +The magic number in cscfg_file_header is defined as two bitfields:: + + [31:8] Fixed magic number to identify file type. + [7:0] Current file format version. + +The following defines determine the maximum overall file size and maximum individual +string size:: + + CSCFG_FILE_MAXSIZE // maximum overall file size. + CSCFG_FILE_STR_MAXSIZE // maximum individual string size.
Add documentation covering the configfs updates that allow binary configuration files to be loaded and unloaded via configfs, along with the demonstration programs in samples. Signed-off-by: Mike Leach <mike.leach@linaro.org> --- .../trace/coresight/coresight-config.rst | 151 +++++++++++++++++- 1 file changed, 145 insertions(+), 6 deletions(-)