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[73.78.62.130]) by smtp.googlemail.com with ESMTPSA id e12-20020a056602044c00b0067c09fd0b53sm1765532iov.21.2022.08.05.14.54.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 05 Aug 2022 14:54:35 -0700 (PDT) From: Jim Cromie To: linux-kernel@vger.kernel.org, jbaron@akamai.com, gregkh@linuxfoundation.org, dri-devel@lists.freedesktop.org, amd-gfx@lists.freedesktop.org, intel-gvt-dev@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org, linux-arm-msm@vger.kernel.org Cc: daniel.vetter@ffwll.ch, seanpaul@chromium.org, robdclark@gmail.com, Jim Cromie Subject: [PATCH v5 14/33] dyndbg: add DECLARE_DYNDBG_CLASSMAP macro Date: Fri, 5 Aug 2022 15:53:36 -0600 Message-Id: <20220805215355.3509287-15-jim.cromie@gmail.com> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220805215355.3509287-1-jim.cromie@gmail.com> References: <20220805215355.3509287-1-jim.cromie@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org With DECLARE_DYNDBG_CLASSMAP modules can declare up to 31 classnames. By doing so, they authorize dyndbg to manipulate class'd prdbgs (ie: __pr_debug_cls, and soon drm_*dbg) :#> echo class DRM_UT_KMS +p > /proc/dynamic_debug/control The macro declares and initializes a static struct ddebug_class_map: - maps approved class-names to class_ids used in module, by array order. forex: DRM_UT_* - class-name vals allow validation of "class FOO" queries using macro is opt-in - enum class_map_type - determines interface, behavior Each module has its own .class_id space, and only known class-names will be authorized for a manipulation. Only DRM stuff should know this: :#> echo class DRM_UT_CORE +p > control # across all modules pr_debugs (with default class_id) are still controllable as before. DECLARE_DYNDBG_CLASSMAP(_var, _maptype, _base, classes...) is:: _var: name of the static struct var. user passes to module_param_cb() if they want a sysfs node. _maptype: this is hard-coded to DD_CLASS_TYPE_DISJOINT_BITS for now. _base: usually 0, it allows splitting 31 classes into subranges, so that multiple classes / sysfs-nodes can share the module's class-id space. classes: list of class_name strings, these are mapped to class-ids starting at _base. This class-names list must have a corresponding ENUM, with SYMBOLS that match the literals, and 1st enum val = _base. enum class_map_type has 4 values, on 2 factors:: - classes are disjoint/independent vs relative/xcontrol interface doesn't enforce the LEVELS relationship, so you could confusingly have V3 enabled, but V1 disabled. OTOH, the control iface already allows infinite tweaking of the underlying callsites; sysfs node readback can only tell the user what they previously wrote. 2. All dyndbg >control reduces to a query/command, includes +/-, which is at-root a kernel patching operation with +/- semantics. And the _NAMES handling exposes it to the user, making it API-adjacent. And its not just >control where +/- gets used (which is settled), the new place is with sysfs-nodes exposing _*_NAMES classes, and here its subtly different. _DISJOINT_NAMES: is simple, independent _LEVEL_NAMES: masks-on bits 0 .. N-1, N..max off # turn on L3,L2,L1 others off echo +L3 > /sys/module/test_dynamic_debug/parameters/p_level_names # turn on L2,L1 others off echo -L3 > /sys/module/test_dynamic_debug/parameters/p_level_names IOW, the - changes the threshold-on bitpos by 1. Alternatively, we could treat the +/- as half-duplex, where -L3 turns off L>2 (and ignores L1), and +L2 would turn on L<=2 (and ignore others). Signed-off-by: Jim Cromie --- . revised DD_CLASS_TYPE_{DISJOINT,LEVEL}_* names . reorder-enum by necessity - _NAMES feature is extra. --- include/linux/dynamic_debug.h | 56 +++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h index cb4696c91901..71cdc8612257 100644 --- a/include/linux/dynamic_debug.h +++ b/include/linux/dynamic_debug.h @@ -56,6 +56,62 @@ struct _ddebug { #endif } __attribute__((aligned(8))); +enum class_map_type { + DD_CLASS_TYPE_DISJOINT_BITS, + /** + * DD_CLASS_TYPE_DISJOINT_BITS: classes are independent, one per bit. + * expecting hex input. Built for drm.debug, basis for other types. + */ + DD_CLASS_TYPE_LEVEL_NUM, + /** + * DD_CLASS_TYPE_LEVEL_NUM: input is numeric level, 0-N. + * N turns on just bits N-1 .. 0, so N=0 turns all bits off. + */ + DD_CLASS_TYPE_DISJOINT_NAMES, + /** + * DD_CLASS_TYPE_DISJOINT_NAMES: input is a CSV of [+-]CLASS_NAMES, + * classes are independent, like _DISJOINT_BITS. Model user + * would be /sys/module/drm/parameters/debug_categories. + */ + DD_CLASS_TYPE_LEVEL_NAMES, + /** + * DD_CLASS_TYPE_LEVEL_NAMES: input is a CSV of [+-]CLASS_NAMES, + * intended for names like: INFO,DEBUG,TRACE, with a module prefix + * avoid EMERG,ALERT,CRIT,ERR,WARNING: they're not debug + */ +}; + +struct ddebug_class_map { + struct list_head link; + struct module *mod; + const char *mod_name; /* needed for builtins */ + const char **class_names; + const int length; + const int base; /* index of 1st .class_id, allows split/shared space */ + enum class_map_type map_type; +}; + +/** + * DECLARE_DYNDBG_CLASSMAP - declare classnames known by a module + * @_var: a struct ddebug_class_map, passed to module_param_cb + * @_type: enum class_map_type, chooses bits/verbose, numeric/symbolic + * @_base: offset of 1st class-name. splits .class_id space + * @classes: class-names used to control class'd prdbgs + */ +#define DECLARE_DYNDBG_CLASSMAP(_var, _maptype, _base, ...) \ + static const char *_var##_classnames[] = { __VA_ARGS__ }; \ + static struct ddebug_class_map __aligned(8) __used \ + __section("__dyndbg_classes") _var = { \ + .mod = THIS_MODULE, \ + .mod_name = KBUILD_MODNAME, \ + .base = _base, \ + .map_type = _maptype, \ + .length = NUM_TYPE_ARGS(char*, __VA_ARGS__), \ + .class_names = _var##_classnames, \ + } +#define NUM_TYPE_ARGS(eltype, ...) \ + (sizeof((eltype[]){__VA_ARGS__}) / sizeof(eltype)) + /* encapsulate linker provided built-in (or module) dyndbg data */ struct _ddebug_info { struct _ddebug *descs;