freedreno/decode: Add code to extent pkt processing with Lua

Setting up a new `iL` `lua_State` in which `r` is injected as
the equivalent to `rnn.init(<gpu>)` and a `priv` library allows
accessing extra functionality (not available to user provided
scripts) currently just allowing writing to registers.

Signed-off-by: Karmjit Mahil <karmjit.mahil@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/38001>

src/freedreno/decode/cffdec.c

@@ -875,6 +875,15 @@ cffdec_init(const struct cffdec_options *_options)
    default:
       errx(-1, "unsupported generation: %u", options->info->chip);
    }
+
+   internal_lua_pkt_handler_load();
+   internal_lua_pkt_handler_init_rnn(rnn);
+}
+
+void
+cffdec_finish(void)
+{
+   internal_lua_pkt_handler_finish();
 }
 
 const char *

src/freedreno/decode/cffdec.h

@@ -112,6 +112,7 @@ uint32_t * parse_cp_indirect(uint32_t *dwords, uint32_t sizedwords,
                              uint64_t *ibaddr, uint32_t *ibsize);
 void reset_regs(void);
 void cffdec_init(const struct cffdec_options *options);
+void cffdec_finish(void);
 void dump_register_val(struct regacc *r, int level);
 void dump_commands(uint32_t *dwords, uint32_t sizedwords, int level);
 

src/freedreno/decode/cffdump-pkt-handler.lua

@@ -0,0 +1,3 @@
+-- SPDX-License-Identifier: MIT
+
+-- `r` is predefined in the environment and is the equivalent of rnn.init(<gpu>)

src/freedreno/decode/cffdump.c

@@ -140,6 +140,8 @@ main(int argc, char **argv)
 
    interactive = isatty(STDOUT_FILENO);
 
+   internal_lua_pkt_handler_load();
+
    options.color = interactive;
 
    while ((c = getopt_long(argc, argv, "vsaS:E:F:D:e:L:q:h", opts, NULL)) !=
@@ -348,6 +350,7 @@ handle_file(const char *filename, int start, int end, int draw)
    }
 
    script_end_cmdstream();
+   cffdec_finish();
 
    reset_buffers();
 

src/freedreno/decode/crashdec.c

@@ -20,6 +20,7 @@
 
 
 #include "crashdec.h"
+#include "cffdec.h"
 
 static FILE *in;
 bool verbose;
@@ -1187,6 +1188,8 @@ cleanup(void)
    if (interactive) {
       pager_close();
    }
+
+   cffdec_finish();
 }
 
 int

src/freedreno/decode/meson.build

@@ -5,6 +5,13 @@ if with_tests
   diff = find_program('diff')
 endif
 
+cffdump_pkt_handler_h = custom_target(
+  'cffdump-pkt-handler.h',
+  input : [files_xxd, 'cffdump-pkt-handler.lua'],
+  output : 'cffdump-pkt-handler.h',
+  command : [prog_python, '@INPUT@', '@OUTPUT@', '-n', 'cffdump_pkt_handler_lua_src'],
+)
+
 # Shared cmdstream decoding:
 libfreedreno_cffdec = static_library(
   'freedreno_cffdec',
@@ -17,7 +24,10 @@ libfreedreno_cffdec = static_library(
     'pager.h',
     'rnnutil.c',
     'rnnutil.h',
+    'script.c',
+    'script.h',
     'util.h',
+    cffdump_pkt_handler_h,
   ],
   include_directories: [
     inc_freedreno,
@@ -27,7 +37,9 @@ libfreedreno_cffdec = static_library(
   ],
   c_args : [ no_override_init_args ],
   gnu_symbol_visibility: 'hidden',
-  dependencies: [],
+  dependencies: [
+    dep_lua,
+  ],
   link_with: [
     libfreedreno_rnn,
     libfreedreno_ir2,  # for disasm_a2xx
@@ -152,8 +164,6 @@ if dep_lua.found() and dep_libarchive.found()
     'cffdump',
     [
       'cffdump.c',
-      'script.c',
-      'script.h'
     ],
     include_directories: [
       inc_freedreno,
@@ -174,6 +184,32 @@ if dep_lua.found() and dep_libarchive.found()
     install: install_fd_decode_tools,
   )
 
+  crashdec = executable(
+    'crashdec',
+    [
+      'crashdec.c',
+      'crashdec.h',
+      'crashdec-hfi.c',
+      'crashdec-mempool.c',
+      'crashdec-prefetch.c',
+    ],
+    include_directories: [
+      inc_freedreno,
+      inc_freedreno_rnn,
+      inc_include,
+      inc_src,
+    ],
+    gnu_symbol_visibility: 'hidden',
+    dependencies: [
+      dep_lua,
+    ],
+    link_with: [
+      libfreedreno_cffdec,
+    ],
+    build_by_default: with_tools.contains('freedreno'),
+    install: install_fd_decode_tools,
+  )
+
   if with_tests
     # dump only a single frame, and single tile pass, to keep the
     # reference output size managable
@@ -209,30 +245,6 @@ else
   warning('lua or libarchive not found, not building cffdump')
 endif
 
-crashdec = executable(
-  'crashdec',
-  [
-    'crashdec.c',
-    'crashdec.h',
-    'crashdec-hfi.c',
-    'crashdec-mempool.c',
-    'crashdec-prefetch.c',
-  ],
-  include_directories: [
-    inc_freedreno,
-    inc_freedreno_rnn,
-    inc_include,
-    inc_src,
-  ],
-  gnu_symbol_visibility: 'hidden',
-  dependencies: [],
-  link_with: [
-    libfreedreno_cffdec,
-  ],
-  build_by_default: with_tools.contains('freedreno'),
-  install: install_fd_decode_tools,
-)
-
 dumpregs = executable(
   'dumpregs',
   [ 'dumpregs.c' ],

src/freedreno/decode/script.c

@@ -20,10 +20,12 @@
 #include "util/u_math.h"
 
 #include "cffdec.h"
+#include "cffdump-pkt-handler.h"
 #include "rnnutil.h"
 #include "script.h"
 
 static lua_State *L;
+static lua_State *iL;
 
 #if 0
 #define DBG(fmt, ...)                                                          \
@@ -547,6 +549,26 @@ static const struct luaL_Reg l_regs[] = {
    {NULL, NULL} /* sentinel */
 };
 
+/* Expose the private functionality to the internal pkt enviroment as a "priv"
+ * library:
+ */
+
+static int
+l_priv_reg_set(lua_State *L)
+{
+   uint32_t regbase = (uint32_t)lua_tonumber(L, 1);
+   uint32_t regval = (uint32_t)lua_tonumber(L, 2);
+
+   reg_set(regbase, regval);
+
+   return 1;
+}
+
+static const struct luaL_Reg l_priv[] = {
+   {"reg_set", l_priv_reg_set},
+   {NULL, NULL} /* sentinel */
+};
+
 /* Expose API to lookup snapshot buffers:
  */
 
@@ -576,11 +598,20 @@ static const struct luaL_Reg l_bos[] = {
 };
 
 static void
-openlib(const char *lib, const luaL_Reg *reg)
+openlib(lua_State *state, const char *lib, const luaL_Reg *reg)
 {
-   lua_newtable(L);
-   luaL_setfuncs(L, reg, 0);
-   lua_setglobal(L, lib);
+   lua_newtable(state);
+   luaL_setfuncs(state, reg, 0);
+   lua_setglobal(state, lib);
+}
+
+static void
+common_libs(lua_State *state)
+{
+   luaL_openlibs(state);
+   openlib(state, "bos", l_bos);
+   openlib(state, "regs", l_regs);
+   openlib(state, "rnn", l_rnn);
 }
 
 /* called at start to load the script: */
@@ -592,10 +623,7 @@ script_load(const char *file)
    assert(!L);
 
    L = luaL_newstate();
-   luaL_openlibs(L);
-   openlib("bos", l_bos);
-   openlib("regs", l_regs);
-   openlib("rnn", l_rnn);
+   common_libs(L);
 
    ret = luaL_loadfile(L, file);
    if (ret)
@@ -608,6 +636,48 @@ script_load(const char *file)
    return 0;
 }
 
+void
+internal_lua_pkt_handler_load(void)
+{
+   int ret;
+
+   if (iL)
+      return;
+
+   iL = luaL_newstate();
+
+   common_libs(iL);
+   openlib(iL, "priv", l_priv);
+
+   ret = luaL_loadstring(iL, cffdump_pkt_handler_lua_src);
+   if (ret) {
+      fprintf(stderr, "%s\n", lua_tostring(iL, -1));
+      exit(1);
+   }
+
+   ret = lua_pcall(iL, 0, LUA_MULTRET, 0);
+   if (ret) {
+      fprintf(stderr, "%s\n", lua_tostring(iL, -1));
+      exit(1);
+   }
+}
+
+void
+internal_lua_pkt_handler_init_rnn(struct rnn *rnn)
+{
+   struct rnndec *rnndec = lua_newuserdata(iL, sizeof(*rnndec));
+   rnndec->base = *rnn;
+   rnndec->sizedwords = 0;
+
+   luaL_newmetatable(iL, "rnnmeta");
+   luaL_setfuncs(iL, l_meta_rnn, 0);
+   lua_pop(iL, 1);
+
+   luaL_setmetatable(iL, "rnnmeta");
+
+   lua_setglobal(iL, "r");
+}
+
 /* called at start of each cmdstream file: */
 void
 script_start_cmdstream(const char *name)
@@ -698,22 +768,24 @@ static const struct luaL_Reg l_meta_rnn_dom[] = {
 
 /* called to general pm4 packet decoding, such as texture/sampler state
  */
-void
-script_packet(uint32_t *dwords, uint32_t sizedwords, struct rnn *rnn,
-              struct rnndomain *dom)
+static bool
+handle_packet_setup(lua_State *state, uint32_t *dwords, uint32_t sizedwords,
+                    struct rnn *rnn, struct rnndomain *dom)
 {
-   if (!L)
-      return;
+   if (!state)
+      return false;
 
-   lua_getglobal(L, dom->name);
+   assert(state == L || state == iL);
+
+   lua_getglobal(state, dom->name);
 
    /* if no handler for the packet, just ignore it: */
-   if (!lua_isfunction(L, -1)) {
-      lua_pop(L, 1);
-      return;
+   if (!lua_isfunction(state, -1)) {
+      lua_pop(state, 1);
+      return false;
    }
 
-   struct rnndec *rnndec = lua_newuserdata(L, sizeof(*rnndec));
+   struct rnndec *rnndec = lua_newuserdata(state, sizeof(*rnndec));
 
    rnndec->base = *rnn;
    rnndec->base.dom[0] = dom;
@@ -721,18 +793,55 @@ script_packet(uint32_t *dwords, uint32_t sizedwords, struct rnn *rnn,
    rnndec->dwords = dwords;
    rnndec->sizedwords = sizedwords;
 
-   luaL_newmetatable(L, "rnnmetadom");
-   luaL_setfuncs(L, l_meta_rnn_dom, 0);
-   lua_pop(L, 1);
+   luaL_newmetatable(state, "rnnmetadom");
+   luaL_setfuncs(state, l_meta_rnn_dom, 0);
+   lua_pop(state, 1);
 
-   luaL_setmetatable(L, "rnnmetadom");
+   luaL_setmetatable(state, "rnnmetadom");
 
-   lua_pushnumber(L, sizedwords);
+   lua_pushnumber(state, sizedwords);
+
+   return true;
+}
+
+void
+script_packet(uint32_t *dwords, uint32_t sizedwords, struct rnn *rnn,
+              struct rnndomain *dom)
+{
+   bool ret;
+
+   ret = handle_packet_setup(L, dwords, sizedwords, rnn, dom);
+   if (!ret)
+      return;
 
    if (lua_pcall(L, 2, 0, 0) != 0)
       error("error running function `f': %s\n");
 }
 
+const char *
+internal_packet(uint32_t *dwords, uint32_t sizedwords, struct rnn *rnn,
+                struct rnndomain *dom)
+{
+   bool ret;
+
+   ret = handle_packet_setup(iL, dwords, sizedwords, rnn, dom);
+   if (!ret)
+      return NULL;
+
+   /* 2 args, 1 result */
+   if (lua_pcall(iL, 2, 1, 0) != 0) {
+      fprintf(stderr, "error running function `f': %s\n",
+              lua_tostring(iL, -1));
+      exit(1);
+   }
+
+   char *str;
+   asprintf(&str, "%s", lua_tostring(iL, -1));
+   lua_pop(iL, 1);
+
+   return str;
+}
+
 /* helper to call fxn that takes and returns void: */
 static void
 simple_call(const char *name)
@@ -786,3 +895,13 @@ script_finish(void)
    lua_close(L);
    L = NULL;
 }
+
+void
+internal_lua_pkt_handler_finish(void)
+{
+   if (!iL)
+      return;
+
+   lua_close(iL);
+   iL = NULL;
+}

src/freedreno/decode/script.h

@@ -18,8 +18,14 @@
 
 #ifdef ENABLE_SCRIPTING
 
+struct rnn;
+struct rnndomain;
+
 /* called at start to load the script: */
 int script_load(const char *file);
+/* called at start to load internal pkt handlers: */
+void internal_lua_pkt_handler_load(void);
+void internal_lua_pkt_handler_init_rnn(struct rnn *rnn);
 
 /* called at start of each cmdstream file: */
 void script_start_cmdstream(const char *name);
@@ -30,13 +36,16 @@ void script_start_cmdstream(const char *name);
 __attribute__((weak))
 void script_draw(const char *primtype, uint32_t nindx);
 
-struct rnn;
-struct rnndomain;
 __attribute__((weak))
 void script_packet(uint32_t *dwords, uint32_t sizedwords,
                    struct rnn *rnn,
                    struct rnndomain *dom);
 
+__attribute__((weak))
+const char * internal_packet(uint32_t *dwords, uint32_t sizedwords,
+                             struct rnn *rnn,
+                             struct rnndomain *dom);
+
 /* maybe at some point it is interesting to add additional script
  * hooks for CP_EVENT_WRITE, etc?
  */
@@ -49,6 +58,7 @@ void script_end_submit(void);
 
 /* called after last cmdstream file: */
 void script_finish(void);
+void internal_lua_pkt_handler_finish(void);
 
 #else
 // TODO no-op stubs..