ac/debug: use an explicit getter for fetching words from the IB
authorNicolai Hähnle <nicolai.haehnle@amd.com>
Fri, 18 Aug 2017 16:06:20 +0000 (18:06 +0200)
committerNicolai Hähnle <nicolai.haehnle@amd.com>
Wed, 23 Aug 2017 11:54:03 +0000 (13:54 +0200)
Guard against out-of-bounds accesses, and prepare for upcoming changes.

Reviewed-by: Marek Olšák <marek.olsak@amd.com>
src/amd/common/ac_debug.c

index 42a72c086b189a759b31c8eb7d16f86ebb38c24a..518893ff481c1bd107c6a8de97f903b247390e0b 100644 (file)
 
 #define INDENT_PKT 8
 
+struct ac_ib_parser {
+       uint32_t *ib;
+       unsigned num_dw;
+       int trace_id;
+       enum chip_class chip_class;
+       ac_debug_addr_callback addr_callback;
+       void *addr_callback_data;
+
+       unsigned cur_dw;
+};
+
+static void ac_do_parse_ib(FILE *f, struct ac_ib_parser *ib);
+
 static void print_spaces(FILE *f, unsigned num)
 {
        fprintf(f, "%*s", num, "");
@@ -129,11 +142,23 @@ void ac_dump_reg(FILE *file, unsigned offset, uint32_t value,
        fprintf(file, COLOR_YELLOW "0x%05x" COLOR_RESET " <- 0x%08x\n", offset, value);
 }
 
-static void ac_parse_set_reg_packet(FILE *f, uint32_t *ib, unsigned count,
-                                   unsigned reg_offset)
+static uint32_t ac_ib_get(struct ac_ib_parser *ib)
+{
+       uint32_t v = 0xdeadbeef;
+
+       if (ib->cur_dw < ib->num_dw)
+               v = ib->ib[ib->cur_dw];
+
+       ib->cur_dw++;
+       return v;
+}
+
+static void ac_parse_set_reg_packet(FILE *f, unsigned count, unsigned reg_offset,
+                                   struct ac_ib_parser *ib)
 {
-       unsigned reg = ((ib[1] & 0xFFFF) << 2) + reg_offset;
-       unsigned index = ib[1] >> 28;
+       unsigned reg_dw = ac_ib_get(ib);
+       unsigned reg = ((reg_dw & 0xFFFF) << 2) + reg_offset;
+       unsigned index = reg_dw >> 28;
        int i;
 
        if (index != 0) {
@@ -142,17 +167,15 @@ static void ac_parse_set_reg_packet(FILE *f, uint32_t *ib, unsigned count,
        }
 
        for (i = 0; i < count; i++)
-               ac_dump_reg(f, reg + i*4, ib[2+i], ~0);
+               ac_dump_reg(f, reg + i*4, ac_ib_get(ib), ~0);
 }
 
-static uint32_t *ac_parse_packet3(FILE *f, uint32_t *ib, int *num_dw,
-                                 int trace_id, enum chip_class chip_class,
-                                 ac_debug_addr_callback addr_callback,
-                                 void *addr_callback_data)
+static void ac_parse_packet3(FILE *f, uint32_t header, struct ac_ib_parser *ib)
 {
-       unsigned count = PKT_COUNT_G(ib[0]);
-       unsigned op = PKT3_IT_OPCODE_G(ib[0]);
-       const char *predicate = PKT3_PREDICATE(ib[0]) ? "(predicate)" : "";
+       unsigned first_dw = ib->cur_dw;
+       int count = PKT_COUNT_G(header);
+       unsigned op = PKT3_IT_OPCODE_G(header);
+       const char *predicate = PKT3_PREDICATE(header) ? "(predicate)" : "";
        int i;
 
        /* Print the name first. */
@@ -179,180 +202,206 @@ static uint32_t *ac_parse_packet3(FILE *f, uint32_t *ib, int *num_dw,
        /* Print the contents. */
        switch (op) {
        case PKT3_SET_CONTEXT_REG:
-               ac_parse_set_reg_packet(f, ib, count, SI_CONTEXT_REG_OFFSET);
+               ac_parse_set_reg_packet(f, count, SI_CONTEXT_REG_OFFSET, ib);
                break;
        case PKT3_SET_CONFIG_REG:
-               ac_parse_set_reg_packet(f, ib, count, SI_CONFIG_REG_OFFSET);
+               ac_parse_set_reg_packet(f, count, SI_CONFIG_REG_OFFSET, ib);
                break;
        case PKT3_SET_UCONFIG_REG:
-               ac_parse_set_reg_packet(f, ib, count, CIK_UCONFIG_REG_OFFSET);
+               ac_parse_set_reg_packet(f, count, CIK_UCONFIG_REG_OFFSET, ib);
                break;
        case PKT3_SET_SH_REG:
-               ac_parse_set_reg_packet(f, ib, count, SI_SH_REG_OFFSET);
+               ac_parse_set_reg_packet(f, count, SI_SH_REG_OFFSET, ib);
                break;
        case PKT3_ACQUIRE_MEM:
-               ac_dump_reg(f, R_0301F0_CP_COHER_CNTL, ib[1], ~0);
-               ac_dump_reg(f, R_0301F4_CP_COHER_SIZE, ib[2], ~0);
-               ac_dump_reg(f, R_030230_CP_COHER_SIZE_HI, ib[3], ~0);
-               ac_dump_reg(f, R_0301F8_CP_COHER_BASE, ib[4], ~0);
-               ac_dump_reg(f, R_0301E4_CP_COHER_BASE_HI, ib[5], ~0);
-               print_named_value(f, "POLL_INTERVAL", ib[6], 16);
+               ac_dump_reg(f, R_0301F0_CP_COHER_CNTL, ac_ib_get(ib), ~0);
+               ac_dump_reg(f, R_0301F4_CP_COHER_SIZE, ac_ib_get(ib), ~0);
+               ac_dump_reg(f, R_030230_CP_COHER_SIZE_HI, ac_ib_get(ib), ~0);
+               ac_dump_reg(f, R_0301F8_CP_COHER_BASE, ac_ib_get(ib), ~0);
+               ac_dump_reg(f, R_0301E4_CP_COHER_BASE_HI, ac_ib_get(ib), ~0);
+               print_named_value(f, "POLL_INTERVAL", ac_ib_get(ib), 16);
                break;
        case PKT3_SURFACE_SYNC:
-               if (chip_class >= CIK) {
-                       ac_dump_reg(f, R_0301F0_CP_COHER_CNTL, ib[1], ~0);
-                       ac_dump_reg(f, R_0301F4_CP_COHER_SIZE, ib[2], ~0);
-                       ac_dump_reg(f, R_0301F8_CP_COHER_BASE, ib[3], ~0);
+               if (ib->chip_class >= CIK) {
+                       ac_dump_reg(f, R_0301F0_CP_COHER_CNTL, ac_ib_get(ib), ~0);
+                       ac_dump_reg(f, R_0301F4_CP_COHER_SIZE, ac_ib_get(ib), ~0);
+                       ac_dump_reg(f, R_0301F8_CP_COHER_BASE, ac_ib_get(ib), ~0);
                } else {
-                       ac_dump_reg(f, R_0085F0_CP_COHER_CNTL, ib[1], ~0);
-                       ac_dump_reg(f, R_0085F4_CP_COHER_SIZE, ib[2], ~0);
-                       ac_dump_reg(f, R_0085F8_CP_COHER_BASE, ib[3], ~0);
+                       ac_dump_reg(f, R_0085F0_CP_COHER_CNTL, ac_ib_get(ib), ~0);
+                       ac_dump_reg(f, R_0085F4_CP_COHER_SIZE, ac_ib_get(ib), ~0);
+                       ac_dump_reg(f, R_0085F8_CP_COHER_BASE, ac_ib_get(ib), ~0);
                }
-               print_named_value(f, "POLL_INTERVAL", ib[4], 16);
+               print_named_value(f, "POLL_INTERVAL", ac_ib_get(ib), 16);
                break;
-       case PKT3_EVENT_WRITE:
-               ac_dump_reg(f, R_028A90_VGT_EVENT_INITIATOR, ib[1],
+       case PKT3_EVENT_WRITE: {
+               uint32_t event_dw = ac_ib_get(ib);
+               ac_dump_reg(f, R_028A90_VGT_EVENT_INITIATOR, event_dw,
                            S_028A90_EVENT_TYPE(~0));
-               print_named_value(f, "EVENT_INDEX", (ib[1] >> 8) & 0xf, 4);
-               print_named_value(f, "INV_L2", (ib[1] >> 20) & 0x1, 1);
+               print_named_value(f, "EVENT_INDEX", (event_dw >> 8) & 0xf, 4);
+               print_named_value(f, "INV_L2", (event_dw >> 20) & 0x1, 1);
                if (count > 0) {
-                       print_named_value(f, "ADDRESS_LO", ib[2], 32);
-                       print_named_value(f, "ADDRESS_HI", ib[3], 16);
+                       print_named_value(f, "ADDRESS_LO", ac_ib_get(ib), 32);
+                       print_named_value(f, "ADDRESS_HI", ac_ib_get(ib), 16);
                }
                break;
-       case PKT3_EVENT_WRITE_EOP:
-               ac_dump_reg(f, R_028A90_VGT_EVENT_INITIATOR, ib[1],
+       }
+       case PKT3_EVENT_WRITE_EOP: {
+               uint32_t event_dw = ac_ib_get(ib);
+               ac_dump_reg(f, R_028A90_VGT_EVENT_INITIATOR, event_dw,
                            S_028A90_EVENT_TYPE(~0));
-               print_named_value(f, "EVENT_INDEX", (ib[1] >> 8) & 0xf, 4);
-               print_named_value(f, "TCL1_VOL_ACTION_ENA", (ib[1] >> 12) & 0x1, 1);
-               print_named_value(f, "TC_VOL_ACTION_ENA", (ib[1] >> 13) & 0x1, 1);
-               print_named_value(f, "TC_WB_ACTION_ENA", (ib[1] >> 15) & 0x1, 1);
-               print_named_value(f, "TCL1_ACTION_ENA", (ib[1] >> 16) & 0x1, 1);
-               print_named_value(f, "TC_ACTION_ENA", (ib[1] >> 17) & 0x1, 1);
-               print_named_value(f, "ADDRESS_LO", ib[2], 32);
-               print_named_value(f, "ADDRESS_HI", ib[3], 16);
-               print_named_value(f, "DST_SEL", (ib[3] >> 16) & 0x3, 2);
-               print_named_value(f, "INT_SEL", (ib[3] >> 24) & 0x7, 3);
-               print_named_value(f, "DATA_SEL", ib[3] >> 29, 3);
-               print_named_value(f, "DATA_LO", ib[4], 32);
-               print_named_value(f, "DATA_HI", ib[5], 32);
+               print_named_value(f, "EVENT_INDEX", (event_dw >> 8) & 0xf, 4);
+               print_named_value(f, "TCL1_VOL_ACTION_ENA", (event_dw >> 12) & 0x1, 1);
+               print_named_value(f, "TC_VOL_ACTION_ENA", (event_dw >> 13) & 0x1, 1);
+               print_named_value(f, "TC_WB_ACTION_ENA", (event_dw >> 15) & 0x1, 1);
+               print_named_value(f, "TCL1_ACTION_ENA", (event_dw >> 16) & 0x1, 1);
+               print_named_value(f, "TC_ACTION_ENA", (event_dw >> 17) & 0x1, 1);
+               print_named_value(f, "ADDRESS_LO", ac_ib_get(ib), 32);
+               uint32_t addr_hi_dw = ac_ib_get(ib);
+               print_named_value(f, "ADDRESS_HI", addr_hi_dw, 16);
+               print_named_value(f, "DST_SEL", (addr_hi_dw >> 16) & 0x3, 2);
+               print_named_value(f, "INT_SEL", (addr_hi_dw >> 24) & 0x7, 3);
+               print_named_value(f, "DATA_SEL", addr_hi_dw >> 29, 3);
+               print_named_value(f, "DATA_LO", ac_ib_get(ib), 32);
+               print_named_value(f, "DATA_HI", ac_ib_get(ib), 32);
                break;
-       case PKT3_RELEASE_MEM:
-               ac_dump_reg(f, R_028A90_VGT_EVENT_INITIATOR, ib[1],
+       }
+       case PKT3_RELEASE_MEM: {
+               uint32_t event_dw = ac_ib_get(ib);
+               ac_dump_reg(f, R_028A90_VGT_EVENT_INITIATOR, event_dw,
                            S_028A90_EVENT_TYPE(~0));
-               print_named_value(f, "EVENT_INDEX", (ib[1] >> 8) & 0xf, 4);
-               print_named_value(f, "TCL1_VOL_ACTION_ENA", (ib[1] >> 12) & 0x1, 1);
-               print_named_value(f, "TC_VOL_ACTION_ENA", (ib[1] >> 13) & 0x1, 1);
-               print_named_value(f, "TC_WB_ACTION_ENA", (ib[1] >> 15) & 0x1, 1);
-               print_named_value(f, "TCL1_ACTION_ENA", (ib[1] >> 16) & 0x1, 1);
-               print_named_value(f, "TC_ACTION_ENA", (ib[1] >> 17) & 0x1, 1);
-               print_named_value(f, "TC_NC_ACTION_ENA", (ib[1] >> 19) & 0x1, 1);
-               print_named_value(f, "TC_WC_ACTION_ENA", (ib[1] >> 20) & 0x1, 1);
-               print_named_value(f, "TC_MD_ACTION_ENA", (ib[1] >> 21) & 0x1, 1);
-               print_named_value(f, "DST_SEL", (ib[2] >> 16) & 0x3, 2);
-               print_named_value(f, "INT_SEL", (ib[2] >> 24) & 0x7, 3);
-               print_named_value(f, "DATA_SEL", ib[2] >> 29, 3);
-               print_named_value(f, "ADDRESS_LO", ib[3], 32);
-               print_named_value(f, "ADDRESS_HI", ib[4], 32);
-               print_named_value(f, "DATA_LO", ib[5], 32);
-               print_named_value(f, "DATA_HI", ib[6], 32);
-               print_named_value(f, "CTXID", ib[7], 32);
+               print_named_value(f, "EVENT_INDEX", (event_dw >> 8) & 0xf, 4);
+               print_named_value(f, "TCL1_VOL_ACTION_ENA", (event_dw >> 12) & 0x1, 1);
+               print_named_value(f, "TC_VOL_ACTION_ENA", (event_dw >> 13) & 0x1, 1);
+               print_named_value(f, "TC_WB_ACTION_ENA", (event_dw >> 15) & 0x1, 1);
+               print_named_value(f, "TCL1_ACTION_ENA", (event_dw >> 16) & 0x1, 1);
+               print_named_value(f, "TC_ACTION_ENA", (event_dw >> 17) & 0x1, 1);
+               print_named_value(f, "TC_NC_ACTION_ENA", (event_dw >> 19) & 0x1, 1);
+               print_named_value(f, "TC_WC_ACTION_ENA", (event_dw >> 20) & 0x1, 1);
+               print_named_value(f, "TC_MD_ACTION_ENA", (event_dw >> 21) & 0x1, 1);
+               uint32_t sel_dw = ac_ib_get(ib);
+               print_named_value(f, "DST_SEL", (sel_dw >> 16) & 0x3, 2);
+               print_named_value(f, "INT_SEL", (sel_dw >> 24) & 0x7, 3);
+               print_named_value(f, "DATA_SEL", sel_dw >> 29, 3);
+               print_named_value(f, "ADDRESS_LO", ac_ib_get(ib), 32);
+               print_named_value(f, "ADDRESS_HI", ac_ib_get(ib), 32);
+               print_named_value(f, "DATA_LO", ac_ib_get(ib), 32);
+               print_named_value(f, "DATA_HI", ac_ib_get(ib), 32);
+               print_named_value(f, "CTXID", ac_ib_get(ib), 32);
                break;
+       }
        case PKT3_WAIT_REG_MEM:
-               print_named_value(f, "OP", ib[1], 32);
-               print_named_value(f, "ADDRESS_LO", ib[2], 32);
-               print_named_value(f, "ADDRESS_HI", ib[3], 32);
-               print_named_value(f, "REF", ib[4], 32);
-               print_named_value(f, "MASK", ib[5], 32);
-               print_named_value(f, "POLL_INTERVAL", ib[6], 16);
+               print_named_value(f, "OP", ac_ib_get(ib), 32);
+               print_named_value(f, "ADDRESS_LO", ac_ib_get(ib), 32);
+               print_named_value(f, "ADDRESS_HI", ac_ib_get(ib), 32);
+               print_named_value(f, "REF", ac_ib_get(ib), 32);
+               print_named_value(f, "MASK", ac_ib_get(ib), 32);
+               print_named_value(f, "POLL_INTERVAL", ac_ib_get(ib), 16);
                break;
        case PKT3_DRAW_INDEX_AUTO:
-               ac_dump_reg(f, R_030930_VGT_NUM_INDICES, ib[1], ~0);
-               ac_dump_reg(f, R_0287F0_VGT_DRAW_INITIATOR, ib[2], ~0);
+               ac_dump_reg(f, R_030930_VGT_NUM_INDICES, ac_ib_get(ib), ~0);
+               ac_dump_reg(f, R_0287F0_VGT_DRAW_INITIATOR, ac_ib_get(ib), ~0);
                break;
        case PKT3_DRAW_INDEX_2:
-               ac_dump_reg(f, R_028A78_VGT_DMA_MAX_SIZE, ib[1], ~0);
-               ac_dump_reg(f, R_0287E8_VGT_DMA_BASE, ib[2], ~0);
-               ac_dump_reg(f, R_0287E4_VGT_DMA_BASE_HI, ib[3], ~0);
-               ac_dump_reg(f, R_030930_VGT_NUM_INDICES, ib[4], ~0);
-               ac_dump_reg(f, R_0287F0_VGT_DRAW_INITIATOR, ib[5], ~0);
+               ac_dump_reg(f, R_028A78_VGT_DMA_MAX_SIZE, ac_ib_get(ib), ~0);
+               ac_dump_reg(f, R_0287E8_VGT_DMA_BASE, ac_ib_get(ib), ~0);
+               ac_dump_reg(f, R_0287E4_VGT_DMA_BASE_HI, ac_ib_get(ib), ~0);
+               ac_dump_reg(f, R_030930_VGT_NUM_INDICES, ac_ib_get(ib), ~0);
+               ac_dump_reg(f, R_0287F0_VGT_DRAW_INITIATOR, ac_ib_get(ib), ~0);
                break;
        case PKT3_INDEX_TYPE:
-               ac_dump_reg(f, R_028A7C_VGT_DMA_INDEX_TYPE, ib[1], ~0);
+               ac_dump_reg(f, R_028A7C_VGT_DMA_INDEX_TYPE, ac_ib_get(ib), ~0);
                break;
        case PKT3_NUM_INSTANCES:
-               ac_dump_reg(f, R_030934_VGT_NUM_INSTANCES, ib[1], ~0);
+               ac_dump_reg(f, R_030934_VGT_NUM_INSTANCES, ac_ib_get(ib), ~0);
                break;
        case PKT3_WRITE_DATA:
-               ac_dump_reg(f, R_370_CONTROL, ib[1], ~0);
-               ac_dump_reg(f, R_371_DST_ADDR_LO, ib[2], ~0);
-               ac_dump_reg(f, R_372_DST_ADDR_HI, ib[3], ~0);
+               ac_dump_reg(f, R_370_CONTROL, ac_ib_get(ib), ~0);
+               ac_dump_reg(f, R_371_DST_ADDR_LO, ac_ib_get(ib), ~0);
+               ac_dump_reg(f, R_372_DST_ADDR_HI, ac_ib_get(ib), ~0);
                for (i = 2; i < count; i++) {
                        print_spaces(f, INDENT_PKT);
-                       fprintf(f, "0x%08x\n", ib[2+i]);
+                       fprintf(f, "0x%08x\n", ac_ib_get(ib));
                }
                break;
        case PKT3_CP_DMA:
-               ac_dump_reg(f, R_410_CP_DMA_WORD0, ib[1], ~0);
-               ac_dump_reg(f, R_411_CP_DMA_WORD1, ib[2], ~0);
-               ac_dump_reg(f, R_412_CP_DMA_WORD2, ib[3], ~0);
-               ac_dump_reg(f, R_413_CP_DMA_WORD3, ib[4], ~0);
-               ac_dump_reg(f, R_414_COMMAND, ib[5], ~0);
+               ac_dump_reg(f, R_410_CP_DMA_WORD0, ac_ib_get(ib), ~0);
+               ac_dump_reg(f, R_411_CP_DMA_WORD1, ac_ib_get(ib), ~0);
+               ac_dump_reg(f, R_412_CP_DMA_WORD2, ac_ib_get(ib), ~0);
+               ac_dump_reg(f, R_413_CP_DMA_WORD3, ac_ib_get(ib), ~0);
+               ac_dump_reg(f, R_414_COMMAND, ac_ib_get(ib), ~0);
                break;
        case PKT3_DMA_DATA:
-               ac_dump_reg(f, R_500_DMA_DATA_WORD0, ib[1], ~0);
-               ac_dump_reg(f, R_501_SRC_ADDR_LO, ib[2], ~0);
-               ac_dump_reg(f, R_502_SRC_ADDR_HI, ib[3], ~0);
-               ac_dump_reg(f, R_503_DST_ADDR_LO, ib[4], ~0);
-               ac_dump_reg(f, R_504_DST_ADDR_HI, ib[5], ~0);
-               ac_dump_reg(f, R_414_COMMAND, ib[6], ~0);
+               ac_dump_reg(f, R_500_DMA_DATA_WORD0, ac_ib_get(ib), ~0);
+               ac_dump_reg(f, R_501_SRC_ADDR_LO, ac_ib_get(ib), ~0);
+               ac_dump_reg(f, R_502_SRC_ADDR_HI, ac_ib_get(ib), ~0);
+               ac_dump_reg(f, R_503_DST_ADDR_LO, ac_ib_get(ib), ~0);
+               ac_dump_reg(f, R_504_DST_ADDR_HI, ac_ib_get(ib), ~0);
+               ac_dump_reg(f, R_414_COMMAND, ac_ib_get(ib), ~0);
                break;
        case PKT3_INDIRECT_BUFFER_SI:
        case PKT3_INDIRECT_BUFFER_CONST:
-       case PKT3_INDIRECT_BUFFER_CIK:
-               ac_dump_reg(f, R_3F0_IB_BASE_LO, ib[1], ~0);
-               ac_dump_reg(f, R_3F1_IB_BASE_HI, ib[2], ~0);
-               ac_dump_reg(f, R_3F2_CONTROL, ib[3], ~0);
-
-               if (addr_callback) {
-                       uint64_t addr = ((uint64_t)ib[2] << 32) | ib[1];
-                       void *data = addr_callback(addr_callback_data, addr);
-                       const char *name = G_3F2_CHAIN(ib[3]) ? "chained" : "nested";
-
-                       if (data)
-                               ac_parse_ib(f, data,  G_3F2_IB_SIZE(ib[3]),
-                                           trace_id, name, chip_class,
-                                           addr_callback, addr_callback_data);
+       case PKT3_INDIRECT_BUFFER_CIK: {
+               uint32_t base_lo_dw = ac_ib_get(ib);
+               ac_dump_reg(f, R_3F0_IB_BASE_LO, base_lo_dw, ~0);
+               uint32_t base_hi_dw = ac_ib_get(ib);
+               ac_dump_reg(f, R_3F1_IB_BASE_HI, base_hi_dw, ~0);
+               uint32_t control_dw = ac_ib_get(ib);
+               ac_dump_reg(f, R_3F2_CONTROL, control_dw, ~0);
+
+               if (!ib->addr_callback)
+                       break;
+
+               uint64_t addr = ((uint64_t)base_hi_dw << 32) | base_lo_dw;
+               void *data = ib->addr_callback(ib->addr_callback_data, addr);
+               if (!data)
+                       break;
+
+               if (G_3F2_CHAIN(control_dw)) {
+                       ib->ib = data;
+                       ib->num_dw = G_3F2_IB_SIZE(control_dw);
+                       ib->cur_dw = 0;
+                       return;
                }
+
+               struct ac_ib_parser ib_recurse;
+               memcpy(&ib_recurse, ib, sizeof(ib_recurse));
+               ib_recurse.ib = data;
+               ib_recurse.num_dw = G_3F2_IB_SIZE(control_dw);
+               ib_recurse.cur_dw = 0;
+
+               fprintf(f, "------------------ nested begin ------------------\n");
+               ac_do_parse_ib(f, &ib_recurse);
+               fprintf(f, "------------------- nested end -------------------\n");
                break;
+       }
        case PKT3_CLEAR_STATE:
        case PKT3_INCREMENT_DE_COUNTER:
        case PKT3_PFP_SYNC_ME:
                break;
        case PKT3_NOP:
-               if (ib[0] == 0xffff1000) {
+               if (header == 0xffff1000) {
                        count = -1; /* One dword NOP. */
-                       break;
-               } else if (count == 0 && AC_IS_TRACE_POINT(ib[1])) {
-                       unsigned packet_id = AC_GET_TRACE_POINT_ID(ib[1]);
+               } else if (count == 0 && ib->cur_dw < ib->num_dw &&
+                          AC_IS_TRACE_POINT(ib->ib[ib->cur_dw])) {
+                       unsigned packet_id = AC_GET_TRACE_POINT_ID(ib->ib[ib->cur_dw]);
 
                        print_spaces(f, INDENT_PKT);
                        fprintf(f, COLOR_RED "Trace point ID: %u\n", packet_id);
 
-                       if (trace_id == -1)
+                       if (ib->trace_id == -1)
                                break; /* tracing was disabled */
 
                        print_spaces(f, INDENT_PKT);
-                       if (packet_id < trace_id)
+                       if (packet_id < ib->trace_id)
                                fprintf(f, COLOR_RED
                                        "This trace point was reached by the CP."
                                        COLOR_RESET "\n");
-                       else if (packet_id == trace_id)
+                       else if (packet_id == ib->trace_id)
                                fprintf(f, COLOR_RED
                                        "!!!!! This is the last trace point that "
                                        "was reached by the CP !!!!!"
                                        COLOR_RESET "\n");
-                       else if (packet_id+1 == trace_id)
+                       else if (packet_id+1 == ib->trace_id)
                                fprintf(f, COLOR_RED
                                        "!!!!! This is the first trace point that "
                                        "was NOT been reached by the CP !!!!!"
@@ -364,51 +413,37 @@ static uint32_t *ac_parse_packet3(FILE *f, uint32_t *ib, int *num_dw,
                                        COLOR_RESET "\n");
                        break;
                }
-               /* fall through, print all dwords */
-       default:
-               for (i = 0; i < count+1; i++) {
-                       print_spaces(f, INDENT_PKT);
-                       fprintf(f, "0x%08x\n", ib[1+i]);
-               }
+               break;
        }
 
-       ib += count + 2;
-       *num_dw -= count + 2;
-       return ib;
+       /* print additional dwords */
+       while (ib->cur_dw <= first_dw + count) {
+               print_spaces(f, INDENT_PKT);
+               fprintf(f, "0x%08x\n", ac_ib_get(ib));
+       }
+
+       if (ib->cur_dw > first_dw + count + 1)
+               fprintf(f, COLOR_RED "!!!!! count in header too low !!!!!"
+                       COLOR_RESET "\n");
 }
 
 /**
  * Parse and print an IB into a file.
- *
- * \param f            file
- * \param ib           IB
- * \param num_dw       size of the IB
- * \param chip_class   chip class
- * \param trace_id     the last trace ID that is known to have been reached
- *                     and executed by the CP, typically read from a buffer
- * \param addr_callback Get a mapped pointer of the IB at a given address. Can
- *                      be NULL.
- * \param addr_callback_data user data for addr_callback
  */
-void ac_parse_ib_chunk(FILE *f, uint32_t *ib, int num_dw, int trace_id,
-                      enum chip_class chip_class,
-                      ac_debug_addr_callback addr_callback, void *addr_callback_data)
+static void ac_do_parse_ib(FILE *f, struct ac_ib_parser *ib)
 {
-       while (num_dw > 0) {
-               unsigned type = PKT_TYPE_G(ib[0]);
+       while (ib->cur_dw < ib->num_dw) {
+               uint32_t header = ac_ib_get(ib);
+               unsigned type = PKT_TYPE_G(header);
 
                switch (type) {
                case 3:
-                       ib = ac_parse_packet3(f, ib, &num_dw, trace_id,
-                                             chip_class, addr_callback,
-                                             addr_callback_data);
+                       ac_parse_packet3(f, header, ib);
                        break;
                case 2:
                        /* type-2 nop */
-                       if (ib[0] == 0x80000000) {
+                       if (header == 0x80000000) {
                                fprintf(f, COLOR_GREEN "NOP (type 2)" COLOR_RESET "\n");
-                               ib++;
-                               num_dw--;
                                break;
                        }
                        /* fall through */
@@ -418,12 +453,39 @@ void ac_parse_ib_chunk(FILE *f, uint32_t *ib, int num_dw, int trace_id,
                }
        }
 
-       if (num_dw < 0) {
+       if (ib->cur_dw > ib->num_dw) {
                printf("\nPacket ends after the end of IB.\n");
                exit(0);
        }
 }
 
+/**
+ * Parse and print an IB into a file.
+ *
+ * \param f            file
+ * \param ib_ptr       IB
+ * \param num_dw       size of the IB
+ * \param chip_class   chip class
+ * \param trace_id     the last trace ID that is known to have been reached
+ *                     and executed by the CP, typically read from a buffer
+ * \param addr_callback Get a mapped pointer of the IB at a given address. Can
+ *                      be NULL.
+ * \param addr_callback_data user data for addr_callback
+ */
+void ac_parse_ib_chunk(FILE *f, uint32_t *ib_ptr, int num_dw, int trace_id,
+                       enum chip_class chip_class,
+                       ac_debug_addr_callback addr_callback, void *addr_callback_data)
+{
+       struct ac_ib_parser ib = {};
+       ib.ib = ib_ptr;
+       ib.num_dw = num_dw;
+       ib.trace_id = trace_id;
+       ib.chip_class = chip_class;
+       ib.addr_callback = addr_callback;
+       ib.addr_callback_data = addr_callback_data;
+       ac_do_parse_ib(f, &ib);
+}
+
 /**
  * Parse and print an IB into a file.
  *