The gvt component of this driver has ~120 pr_debugs, in 9 "classes". Following the interface model of drm.debug, add a parameter to map bits to these classes.
If CONFIG_DRM_USE_DYNAMIC_DEBUG=y (and CONFIG_DYNAMIC_DEBUG_CORE), add -DDYNAMIC_DEBUG_MODULE into Makefile. TBD: maybe add a separate CONFIG_I915_USE_DYNAMIC_DEBUG to more fully optionalize this.
In i915_params.c, add callback to map bits to queries.
TBD: the callback code should probably be moved to lib/dynamic_debug, and given a declarative interface, with implied bit-numbering, something like:
MOD_PARM_BITMAP_DESC(__gvt_debug, "gvt: cmd: ", "command processing" "gvt: core: ", "core help", "gvt: dpy: ", "display help", "gvt: el: ", "help", "gvt: irq: ", "help", "gvt: mm: ", "help", "gvt: mmio: ", "help", "gvt: render: ", "help", "gvt: sched: " "help"); --- drivers/gpu/drm/i915/gvt/Makefile | 4 ++ drivers/gpu/drm/i915/i915_params.c | 76 ++++++++++++++++++++++++++++++ 2 files changed, 80 insertions(+)
diff --git a/drivers/gpu/drm/i915/gvt/Makefile b/drivers/gpu/drm/i915/gvt/Makefile index ea8324abc784..846ba73b8de6 100644 --- a/drivers/gpu/drm/i915/gvt/Makefile +++ b/drivers/gpu/drm/i915/gvt/Makefile @@ -7,3 +7,7 @@ GVT_SOURCE := gvt.o aperture_gm.o handlers.o vgpu.o trace_points.o firmware.o \
ccflags-y += -I $(srctree)/$(src) -I $(srctree)/$(src)/$(GVT_DIR)/ i915-y += $(addprefix $(GVT_DIR)/, $(GVT_SOURCE)) + +#ifdef CONFIG_DRM_USE_DYNAMIC_DEBUG +ccflags-y += -DDYNAMIC_DEBUG_MODULE +#endif diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c index e07f4cfea63a..e0d13aff5274 100644 --- a/drivers/gpu/drm/i915/i915_params.c +++ b/drivers/gpu/drm/i915/i915_params.c @@ -265,3 +265,79 @@ void i915_params_free(struct i915_params *params) I915_PARAMS_FOR_EACH(FREE); #undef FREE } + +/* POC for callback -> dynamic_debug_exec_queries */ +unsigned long __gvt_debug; +EXPORT_SYMBOL(__gvt_debug); + +static char *format_prefix_classes[] = { + "gvt: cmd: ", + "gvt: core: ", + "gvt: dpy: ", + "gvt: el: ", + "gvt: irq: ", + "gvt: mm: ", + "gvt: mmio: ", + "gvt: render: ", + "gvt: sched: " +}; +#define NUM_CLASSES ARRAY_SIZE(format_prefix_classes) +#define OUR_QUERY_SIZE 128 /* we need about 20 */ + +#include <linux/module.h> + +static int param_set_dyndbg(const char *instr, const struct kernel_param *kp) +{ + unsigned int val; + unsigned long changes, result; + int rc, chgct = 0, totct = 0, bitpos; + char query[OUR_QUERY_SIZE]; + + rc = kstrtouint(instr, 0, &val); + 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 ^ __gvt_debug; + + for_each_set_bit(bitpos, &changes, NUM_CLASSES) { + + sprintf(query, "format '^%s' %cp", format_prefix_classes[bitpos], + test_bit(bitpos, &result) ? '+' : '-'); + + chgct = dynamic_debug_exec_queries(query, "i915"); + + pr_info("%d changes on: %s\n", chgct, query); + totct += chgct; + } + pr_info("total changes: %d\n", totct); + __gvt_debug = result; + 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, +}; + +#define info_ln(hexi, prefix) "\n\t0x" __stringify(hexi) "\t" prefix + +MODULE_PARM_DESC(debug_gvt, " gvt debug categories:" + info_ln(1, "gvt: cmd:") + info_ln(2, "gvt: core:") + info_ln(4, "gvt: dpy:") + info_ln(8, "gvt: el:") + info_ln(10, "gvt: irq:") + info_ln(20, "gvt: mm:") + info_ln(40, "gvt: mmio:") + info_ln(80, "gvt: render:") + info_ln(100, "gvt: sched:")); + +module_param_cb(debug_gvt, ¶m_ops_dyndbg, &__gvt_debug, 0644);