The gvt component of this driver has ~120 pr_debugs, in 9 "classes".
Add a "knob", like drm.debug, to map bits to these classes.
bash-5.0# echo 0x01 > /sys/module/i915/parameters/debug_dyn
set_dyndbg: result:0x1 from 0x01
dyndbg: query 0: "format='^gvt: cmd: ' +p"
dyndbg: entry, buf:'format='^gvt: cmd: ' +p'
dyndbg: start-of-word:0 'format='^gvt: cmd: ' +p'
dyndbg: start-of-word:1 ''^gvt: cmd: ' +p'
dyndbg: start-of-word:2 '+p'
dyndbg: split into words: "format" "^gvt: cmd: " "+p"
dyndbg: op='+'
dyndbg: flags=0x1
dyndbg: *flagsp=0x1 *maskp=0x
dyndbg: key:'format' arg:'^gvt: cmd: '
dyndbg: parsed: func="" file="" module="i915" format="^gvt: cmd: " lineno=0-0
dyndbg: changed drivers/gpu/drm/i915/gvt/cmd_parser.c:3081
[i915]init_cmd_table =p
dyndbg: changed drivers/gpu/drm/i915/gvt/cmd_parser.c:1376
[i915]gen8_check_mi_display_flip =p
dyndbg: changed drivers/gpu/drm/i915/gvt/cmd_parser.c:1373
[i915]gen8_check_mi_display_flip =p
dyndbg: changed drivers/gpu/drm/i915/gvt/cmd_parser.c:745
[i915]parser_exec_state_dump =p
dyndbg: changed drivers/gpu/drm/i915/gvt/cmd_parser.c:744
[i915]parser_exec_state_dump =p
dyndbg: changed drivers/gpu/drm/i915/gvt/cmd_parser.c:742
[i915]parser_exec_state_dump =p
dyndbg: changed drivers/gpu/drm/i915/gvt/cmd_parser.c:733
[i915]parser_exec_state_dump =p
dyndbg: changed drivers/gpu/drm/i915/gvt/cmd_parser.c:729
[i915]parser_exec_state_dump =p
dyndbg: changed drivers/gpu/drm/i915/gvt/cmd_parser.c:722
[i915]parser_exec_state_dump =p
dyndbg: changed drivers/gpu/drm/i915/gvt/cmd_parser.c:716
[i915]parser_exec_state_dump =p
dyndbg: changed drivers/gpu/drm/i915/gvt/cmd_parser.c:691 [i915]print_opcode =p
dyndbg: applied: func="" file="" module="i915" format="^gvt: cmd: " lineno=0-0
dyndbg: processed 1 queries, with 11 matches, 0 errs
change ct:11 on format='gvt: cmd: '
change ct:11
Signed-off-by: Jim Cromie
---
drivers/gpu/drm/i915/i915_params.c | 76 ++
1 file changed, 76 insertions(+)
diff --git a/drivers/gpu/drm/i915/i915_params.c
b/drivers/gpu/drm/i915/i915_params.c
index 8d8db9ff0a48..4e1f01ab4865 100644
--- a/drivers/gpu/drm/i915/i915_params.c
+++ b/drivers/gpu/drm/i915/i915_params.c
@@ -255,3 +255,79 @@ void i915_params_free(struct i915_params *params)
I915_PARAMS_FOR_EACH(FREE);
#undef FREE
}
+
+/* POC for callback -> dynamic_debug_exec_queries */
+unsigned long __new_knob;
+EXPORT_SYMBOL(__new_knob);
+
+static char *pr_debug_classes[] = {
+ "gvt: cmd: ",
+ "gvt: core: ",
+ "gvt: dpy: ",
+ "gvt: el: ",
+ "gvt: irq: ",
+ "gvt: mm: ",
+ "gvt: mmio: ",
+ "gvt: render: ",
+ "gvt: sched: "
+};
+#define NUM_CLASSESARRAY_SIZE(pr_debug_classes)
+#define OUR_QUERY_SIZE 128 /* we need about 20 */
+
+#include
+
+static int param_set_dyndbg(const char *instr, const struct kernel_param *kp)
+{
+ static unsigned long int old_val;
+unsigned int val;
+ unsigned long int changes, result;
+ int rc, chgct = 0, totct = 0, bitpos;
+ char query[OUR_QUERY_SIZE];
+
+ rc = kstrtouint(instr, 0, );
+ if (rc) {
+ pr_err("set_dyndbg: failed\n");
+ return -EINVAL;
+ }
+ result = val;
+ pr_info("set_dyndbg: result:0x%lx from %s\n", result, instr);
+
+ changes = result ^ old_val;
+
+ for_each_set_bit(bitpos, , NUM_CLASSES) {
+
+ sprintf(query, "format='^%s' %cp", pr_debug_classes[bitpos],
+ test_bit(bitpos, ) ? '+' : '-');
+
+ chgct = dynamic_debug_exec_queries(query, "i915");
+ totct += chgct;
+ pr_info("change ct:%d on format='%s'\n", chgct,
+ pr_debug_classes[bitpos]);
+ }
+ old_val = result;
+ pr_info("change ct:%d\n", totct);
+ return 0;
+}
+static int param_get_dyndbg(char *buffer, const struct kernel_param *kp)
+{
+ return scnprintf(buffer, PAGE_SIZE, "%u\n",
+*((unsigned int *)kp->arg));
+}
+static const struct kernel_param_ops param_ops_dyndbg = {
+ .set = param_set_dyndbg,
+ .get = param_get_dyndbg,
+};
+
+MODULE_PARM_DESC(debug_dyn, " enable dynamic-debug by format-string
classifications.\n"
+"\t\twhich are:"
+"\n\t\t gvt: cmd:"
+"\n\t\t gvt: core:"
+"\n\t\t gvt: dpy:"
+"\n\t\t gvt: el:"
+"\n\t\t gvt: irq:"
+"\n\t\t gvt: mm:"
+"\n\t\t gvt: mmio:"
+"\n\t\t gvt: render:"
+"\n\t\t gvt: sched:" "\n");
+
+module_param_cb(debug_dyn, _ops_dyndbg, &__new_knob, 0644);
--
2.26.2
