[PATCH 4/6] coresight: samples: Add an example config writer for configfs load
Mike Leach
mike.leach at linaro.org
Mon Nov 1 15:47:29 PDT 2021
Add an example file generator to test loading configurations via a
binary attribute in configfs.
Provides a file buffer writer function that can be re-used in other
userspace programs.
Buffer write format matches that expected by the corresponding reader
in the configfs driver code.
Signed-off-by: Mike Leach <mike.leach at linaro.org>
---
samples/coresight/Makefile | 7 +
samples/coresight/coresight-cfg-bufw.c | 302 ++++++++++++++++++++++
samples/coresight/coresight-cfg-bufw.h | 24 ++
samples/coresight/coresight-cfg-filegen.c | 89 +++++++
4 files changed, 422 insertions(+)
create mode 100644 samples/coresight/coresight-cfg-bufw.c
create mode 100644 samples/coresight/coresight-cfg-bufw.h
create mode 100644 samples/coresight/coresight-cfg-filegen.c
diff --git a/samples/coresight/Makefile b/samples/coresight/Makefile
index b3fce4af2347..07bfd99d7a68 100644
--- a/samples/coresight/Makefile
+++ b/samples/coresight/Makefile
@@ -1,4 +1,11 @@
# SPDX-License-Identifier: GPL-2.0-only
+# coresight config - loadable module configuration.
obj-$(CONFIG_SAMPLE_CORESIGHT_SYSCFG) += coresight-cfg-sample.o
ccflags-y += -I$(srctree)/drivers/hwtracing/coresight
+
+# coresight config - configfs loadable binary config generator
+userprogs-always-y += coresight-cfg-filegen
+
+coresight-cfg-filegen-objs := coresight-cfg-filegen.o coresight-cfg-bufw.o
+userccflags += -I$(srctree)/drivers/hwtracing/coresight
diff --git a/samples/coresight/coresight-cfg-bufw.c b/samples/coresight/coresight-cfg-bufw.c
new file mode 100644
index 000000000000..8c32a8509eef
--- /dev/null
+++ b/samples/coresight/coresight-cfg-bufw.c
@@ -0,0 +1,302 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2020 Linaro Limited, All rights reserved.
+ * Author: Mike Leach <mike.leach at linaro.org>
+ */
+
+#include <string.h>
+
+#include "coresight-cfg-bufw.h"
+
+/*
+ * Set of macros to make writing the buffer code easier.
+ *.
+ * Uses naming convention as 'buffer' for the buffer pointer and
+ * 'used' as the current bytes used by the encosing function.
+ */
+#define cscfg_write_u64(val64) { \
+ *(u64 *)(buffer + used) = val64; \
+ used += sizeof(u64); \
+ }
+
+#define cscfg_write_u32(val32) { \
+ *(u32 *)(buffer + used) = val32; \
+ used += sizeof(u32); \
+ }
+
+#define cscfg_write_u16(val16) { \
+ *(u16 *)(buffer + used) = val16; \
+ used += sizeof(u16); \
+ }
+
+#define cscfg_write_u8(val8) { \
+ *(buffer + used) = val8; \
+ used++; \
+ }
+
+#define CHECK_WRET(rval) { \
+ if (rval < 0) \
+ return rval; \
+ used += rval; \
+ }
+
+/* write the header at the start of the buffer */
+static int cscfg_file_write_fhdr(u8 *buffer, const int buflen,
+ const struct cscfg_file_header *fhdr)
+{
+ int used = 0;
+
+ cscfg_write_u32(fhdr->magic_version);
+ cscfg_write_u16(fhdr->length);
+ cscfg_write_u16(fhdr->nr_features);
+ return used;
+}
+
+static int cscfg_file_write_string(u8 *buffer, const int buflen, const char *string)
+{
+ int len, used = 0;
+
+ len = strlen(string);
+ if (len > CSCFG_FILE_STR_MAXSIZE)
+ return -EINVAL;
+
+ if (buflen < (len + 1 + sizeof(u16)))
+ return -EINVAL;
+
+ cscfg_write_u16((u16)(len + 1));
+ strcpy((char *)(buffer + used), string);
+ used += (len + 1);
+
+ return used;
+}
+
+static int cscfg_file_write_elem_hdr(u8 *buffer, const int buflen,
+ struct cscfg_file_elem_header *ehdr)
+{
+ int used = 0;
+
+ if (buflen < (sizeof(u16) + sizeof(u8)))
+ return -EINVAL;
+
+ cscfg_write_u16(ehdr->elem_length);
+ cscfg_write_u8(ehdr->elem_type);
+
+ return used;
+}
+
+
+static int cscfg_file_write_config(u8 *buffer, const int buflen,
+ struct cscfg_config_desc *config_desc)
+{
+ int used = 0, bytes_w, space_req, preset_bytes, i;
+ struct cscfg_file_elem_header ehdr;
+
+ ehdr.elem_length = 0;
+ ehdr.elem_type = CSCFG_FILE_ELEM_TYPE_CFG;
+
+ /* write element header at current buffer location */
+ bytes_w = cscfg_file_write_elem_hdr(buffer, buflen, &ehdr);
+ CHECK_WRET(bytes_w);
+
+ /* write out the configuration name */
+ bytes_w = cscfg_file_write_string(buffer + used, buflen - used,
+ config_desc->name);
+ CHECK_WRET(bytes_w);
+
+ /* write out the description string */
+ bytes_w = cscfg_file_write_string(buffer + used, buflen - used,
+ config_desc->description);
+ CHECK_WRET(bytes_w);
+
+ /*
+ * calculate the space needed for variables + presets
+ * [u16 value - nr_presets]
+ * [u32 value - nr_total_params]
+ * [u16 value - nr_feat_refs]
+ * [u64 values] * (nr_presets * nr_total_params)
+ */
+ preset_bytes = sizeof(u64) * config_desc->nr_presets * config_desc->nr_total_params;
+ space_req = (sizeof(u16) * 2) + sizeof(u32) + preset_bytes;
+
+ if ((buflen - used) < space_req)
+ return -EINVAL;
+
+ cscfg_write_u16((u16)config_desc->nr_presets);
+ cscfg_write_u32((u32)config_desc->nr_total_params);
+ cscfg_write_u16((u16)config_desc->nr_feat_refs);
+ if (preset_bytes) {
+ memcpy(buffer + used, (u8 *)config_desc->presets, preset_bytes);
+ used += preset_bytes;
+ }
+
+ /* now write the feature ref names */
+ for (i = 0; i < config_desc->nr_feat_refs; i++) {
+ bytes_w = cscfg_file_write_string(buffer + used, buflen - used,
+ config_desc->feat_ref_names[i]);
+ CHECK_WRET(bytes_w);
+ }
+
+ /* rewrite the element header with the correct length */
+ ehdr.elem_length = used;
+ bytes_w = cscfg_file_write_elem_hdr(buffer, buflen, &ehdr);
+ /* no CHECK_WRET as used must not be updated */
+ if (bytes_w < 0)
+ return bytes_w;
+
+ return used;
+}
+
+/*
+ * write a parameter structure into the buffer in following format:
+ * [cscfg_file_elem_str] - parameter name.
+ * [u64 value: param_value] - initial value.
+ */
+static int cscfg_file_write_param(u8 *buffer, const int buflen,
+ struct cscfg_parameter_desc *param_desc)
+{
+ int used = 0, bytes_w;
+
+ bytes_w = cscfg_file_write_string(buffer + used, buflen - used,
+ param_desc->name);
+ CHECK_WRET(bytes_w);
+
+ if ((buflen - used) < sizeof(u64))
+ return -EINVAL;
+
+ cscfg_write_u64(param_desc->value);
+ return used;
+}
+/*
+ * Write a feature element from cscfg_feature_desc in following format:
+ *
+ * [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]
+ * [u16 value: nr_regs] - number of registers.
+ * [u16 value: nr_params] - number of parameters.
+ * [cscfg_regval_desc struct] * nr_regs
+ * [PARAM_ELEM] * nr_params
+ *
+ *
+ */
+static int cscfg_file_write_feat(u8 *buffer, const int buflen,
+ struct cscfg_feature_desc *feat_desc)
+{
+ struct cscfg_file_elem_header ehdr;
+ struct cscfg_regval_desc *p_reg_desc;
+ int used = 0, bytes_w, i, space_req;
+ u32 val32;
+
+ ehdr.elem_length = 0;
+ ehdr.elem_type = CSCFG_FILE_ELEM_TYPE_FEAT;
+
+ /* write element header at current buffer location */
+ bytes_w = cscfg_file_write_elem_hdr(buffer, buflen, &ehdr);
+ CHECK_WRET(bytes_w);
+
+ /* write out the name string */
+ bytes_w = cscfg_file_write_string(buffer + used, buflen - used,
+ feat_desc->name);
+ CHECK_WRET(bytes_w)
+
+ /* write out the description string */
+ bytes_w = cscfg_file_write_string(buffer + used, buflen - used,
+ feat_desc->description);
+ CHECK_WRET(bytes_w);
+
+ /* check for space for variables and register structures */
+ space_req = (sizeof(u16) * 2) + sizeof(u32) +
+ (sizeof(struct cscfg_regval_desc) * feat_desc->nr_regs);
+ if ((buflen - used) < space_req)
+ return -EINVAL;
+
+ /* write the variables */
+ cscfg_write_u32((u32)feat_desc->match_flags);
+ cscfg_write_u16((u16)feat_desc->nr_regs);
+ cscfg_write_u16((u16)feat_desc->nr_params);
+
+ /*write the registers */
+ for (i = 0; i < feat_desc->nr_regs; i++) {
+ p_reg_desc = (struct cscfg_regval_desc *)&feat_desc->regs_desc[i];
+ CSCFG_FILE_REG_DESC_INFO_TO_U32(val32, p_reg_desc);
+ cscfg_write_u32(val32);
+ cscfg_write_u64(feat_desc->regs_desc[i].val64);
+ }
+
+ /* write any parameters */
+ for (i = 0; i < feat_desc->nr_params; i++) {
+ bytes_w = cscfg_file_write_param(buffer + used, buflen - used,
+ &feat_desc->params_desc[i]);
+ CHECK_WRET(bytes_w);
+ }
+
+ /*
+ * rewrite the element header at the start of the buffer block
+ * with the correct length
+ */
+ ehdr.elem_length = used;
+ bytes_w = cscfg_file_write_elem_hdr(buffer, buflen, &ehdr);
+ /* no CHECK_WRET as used must not be updated */
+ if (bytes_w < 0)
+ return bytes_w;
+
+ return used;
+}
+
+/*
+ * write a buffer from the configuration and feature
+ * descriptors to write into a file for configfs.
+ *
+ * Will only write one config, and/or a number of features,
+ * per the file standard.
+ */
+int cscfg_file_write_buffer(u8 *buffer, const int buflen,
+ struct cscfg_config_desc *config_desc,
+ struct cscfg_feature_desc **feat_descs)
+{
+ struct cscfg_file_header fhdr;
+ int used = 0, bytes_w, i;
+
+ /* init the file header */
+ fhdr.magic_version = CSCFG_FILE_MAGIC_VERSION;
+ fhdr.length = 0;
+ fhdr.nr_features = 0;
+
+ /* count the features */
+ if (feat_descs) {
+ while (feat_descs[fhdr.nr_features])
+ fhdr.nr_features++;
+ }
+
+ /* need a buffer and at least one config or feature */
+ if ((!config_desc && !fhdr.nr_features) ||
+ !buffer || (buflen > CSCFG_FILE_MAXSIZE))
+ return -EINVAL;
+
+ /* write a header at the start to get the length of the header */
+ bytes_w = cscfg_file_write_fhdr(buffer, buflen, &fhdr);
+ CHECK_WRET(bytes_w);
+
+ /* write a single config */
+ if (config_desc) {
+ bytes_w = cscfg_file_write_config(buffer + used, buflen - used,
+ config_desc);
+ CHECK_WRET(bytes_w);
+ }
+
+ /* write any features */
+ for (i = 0; i < fhdr.nr_features; i++) {
+ bytes_w = cscfg_file_write_feat(buffer + used, buflen - used,
+ feat_descs[i]);
+ CHECK_WRET(bytes_w);
+ }
+
+ /* finally re-write the header at the buffer start with the correct length */
+ fhdr.length = (u16)used;
+ bytes_w = cscfg_file_write_fhdr(buffer, buflen, &fhdr);
+ /* no CHECK_WRET as used must not be updated */
+ if (bytes_w < 0)
+ return bytes_w;
+ return used;
+}
diff --git a/samples/coresight/coresight-cfg-bufw.h b/samples/coresight/coresight-cfg-bufw.h
new file mode 100644
index 000000000000..00b16c583cad
--- /dev/null
+++ b/samples/coresight/coresight-cfg-bufw.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2020 Linaro Limited, All rights reserved.
+ * Author: Mike Leach <mike.leach at linaro.org>
+ */
+
+#ifndef _CORESIGHT_CFG_BUFW_H
+#define _CORESIGHT_CFG_BUFW_H
+
+#include "coresight-config-file.h"
+
+/*
+ * Function to take coresight configurations and features and
+ * write them into a supplied memory buffer for serialisation
+ * into a file.
+ *
+ * Resulting file can then be loaded into the coresight
+ * infrastructure via configfs.
+ */
+int cscfg_file_write_buffer(u8 *buffer, const int buflen,
+ struct cscfg_config_desc *config_desc,
+ struct cscfg_feature_desc **feat_descs);
+
+#endif /* _CORESIGHT_CFG_BUFW_H */
diff --git a/samples/coresight/coresight-cfg-filegen.c b/samples/coresight/coresight-cfg-filegen.c
new file mode 100644
index 000000000000..c8be18ee97b6
--- /dev/null
+++ b/samples/coresight/coresight-cfg-filegen.c
@@ -0,0 +1,89 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2020 Linaro Limited, All rights reserved.
+ * Author: Mike Leach <mike.leach at linaro.org>
+ */
+
+#include <linux/types.h>
+#include <linux/unistd.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#include "coresight-cfg-bufw.h"
+
+/*
+ * generate example binary coresight configuration files for loading
+ * into the coresight subsystem via configfs
+ */
+
+/* create a similar configuration example as the coresight-cfg-sample.c file. */
+
+/* we will provide 4 sets of preset parameter values */
+#define AFDO2_NR_PRESETS 4
+/* the total number of parameters in used features - strobing has 2 */
+#define AFDO2_NR_PARAM_SUM 2
+
+static const char *afdo2_ref_names[] = {
+ "strobing",
+};
+
+/*
+ * set of presets leaves strobing window constant while varying period to allow
+ * experimentation with mark / space ratios for various workloads
+ */
+static u64 afdo2_presets[AFDO2_NR_PRESETS][AFDO2_NR_PARAM_SUM] = {
+ { 2000, 100 },
+ { 2000, 1000 },
+ { 2000, 5000 },
+ { 2000, 10000 },
+};
+
+struct cscfg_config_desc afdo3 = {
+ .name = "autofdo3",
+ .description = "Setup ETMs with strobing for autofdo\n"
+ "Supplied presets allow experimentation with mark-space ratio for various loads\n",
+ .nr_feat_refs = ARRAY_SIZE(afdo2_ref_names),
+ .feat_ref_names = afdo2_ref_names,
+ .nr_presets = AFDO2_NR_PRESETS,
+ .nr_total_params = AFDO2_NR_PARAM_SUM,
+ .presets = &afdo2_presets[0][0],
+};
+
+static struct cscfg_feature_desc *sample_feats[] = {
+ NULL
+};
+
+static struct cscfg_config_desc *sample_cfgs[] = {
+ &afdo3,
+ NULL
+};
+
+
+#define CSCFG_BIN_FILENAME "example1.cscfg"
+
+int main(int argc, char **argv)
+{
+ u8 buffer[CSCFG_FILE_MAXSIZE];
+ int used;
+ FILE *fp;
+
+ printf("Coresight Configuration file Generator\n\n");
+
+ used = cscfg_file_write_buffer(buffer, CSCFG_FILE_MAXSIZE,
+ sample_cfgs[0], sample_feats);
+
+ if (used < 0) {
+ printf("Error %d writing configuration %s into buffer\n",
+ used, sample_cfgs[0]->name);
+ return used;
+ }
+
+ fp = fopen(CSCFG_BIN_FILENAME, "wb");
+ if (fp == NULL) {
+ printf("Error opening file %s\n", CSCFG_BIN_FILENAME);
+ return -1;
+ }
+ fwrite(buffer, used, sizeof(u8), fp);
+ fclose(fp);
+ return 0;
+}
--
2.17.1
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