pan/decode: Add hexdump helper

I think I originally wrote this for Asahi? Should probably be moved to
util/...

Signed-off-by: Alyssa Rosenzweig <alyssa@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/14543>

src/panfrost/lib/genxml/decode.h

@@ -90,4 +90,47 @@ void GENX(pandecode_jc)(mali_ptr jc_gpu_va, unsigned gpu_id);
 void GENX(pandecode_abort_on_fault)(mali_ptr jc_gpu_va);
 #endif
 
+static inline void
+pan_hexdump(FILE *fp, const uint8_t *hex, size_t cnt, bool with_strings)
+{
+        for (unsigned i = 0; i < cnt; ++i) {
+                if ((i & 0xF) == 0)
+                        fprintf(fp, "%06X  ", i);
+
+                uint8_t v = hex[i];
+
+                if (v == 0 && (i & 0xF) == 0) {
+                        /* Check if we're starting an aligned run of zeroes */
+                        unsigned zero_count = 0;
+
+                        for (unsigned j = i; j < cnt; ++j) {
+                                if (hex[j] == 0)
+                                        zero_count++;
+                                else
+                                        break;
+                        }
+
+                        if (zero_count >= 32) {
+                                fprintf(fp, "*\n");
+                                i += (zero_count & ~0xF) - 1;
+                                continue;
+                        }
+                }
+
+                fprintf(fp, "%02X ", hex[i]);
+                if ((i & 0xF) == 0xF && with_strings) {
+                        fprintf(fp, " | ");
+                        for (unsigned j = i & ~0xF; j <= i; ++j) {
+                                uint8_t c = hex[j];
+                                fputc((c < 32 || c > 128) ? '.' : c, fp);
+                        }
+                }
+
+                if ((i & 0xF) == 0xF)
+                        fprintf(fp, "\n");
+        }
+
+        fprintf(fp, "\n");
+}
+
 #endif /* __MMAP_TRACE_H__ */