diff options
Diffstat (limited to 'include/exec/exec-all.h')
| -rw-r--r-- | include/exec/exec-all.h | 44 |
1 files changed, 28 insertions, 16 deletions
diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h index 6c113a3..445d946 100644 --- a/include/exec/exec-all.h +++ b/include/exec/exec-all.h @@ -259,20 +259,32 @@ struct TranslationBlock { struct TranslationBlock *page_next[2]; tb_page_addr_t page_addr[2]; - /* the following data are used to directly call another TB from - the code of this one. */ - uint16_t tb_next_offset[2]; /* offset of original jump target */ + /* The following data are used to directly call another TB from + * the code of this one. This can be done either by emitting direct or + * indirect native jump instructions. These jumps are reset so that the TB + * just continue its execution. The TB can be linked to another one by + * setting one of the jump targets (or patching the jump instruction). Only + * two of such jumps are supported. + */ + uint16_t jmp_reset_offset[2]; /* offset of original jump target */ +#define TB_JMP_RESET_OFFSET_INVALID 0xffff /* indicates no jump generated */ #ifdef USE_DIRECT_JUMP - uint16_t tb_jmp_offset[2]; /* offset of jump instruction */ + uint16_t jmp_insn_offset[2]; /* offset of native jump instruction */ #else - uintptr_t tb_next[2]; /* address of jump generated code */ + uintptr_t jmp_target_addr[2]; /* target address for indirect jump */ #endif - /* list of TBs jumping to this one. This is a circular list using - the two least significant bits of the pointers to tell what is - the next pointer: 0 = jmp_next[0], 1 = jmp_next[1], 2 = - jmp_first */ - struct TranslationBlock *jmp_next[2]; - struct TranslationBlock *jmp_first; + /* Each TB has an assosiated circular list of TBs jumping to this one. + * jmp_list_first points to the first TB jumping to this one. + * jmp_list_next is used to point to the next TB in a list. + * Since each TB can have two jumps, it can participate in two lists. + * The two least significant bits of a pointer are used to choose which + * data field holds a pointer to the next TB: + * 0 => jmp_list_next[0], 1 => jmp_list_next[1], 2 => jmp_list_first. + * In other words, 0/1 tells which jump is used in the pointed TB, + * and 2 means that this is a pointer back to the target TB of this list. + */ + struct TranslationBlock *jmp_list_next[2]; + struct TranslationBlock *jmp_list_first; }; #include "qemu/thread.h" @@ -340,7 +352,7 @@ void tb_set_jmp_target1(uintptr_t jmp_addr, uintptr_t addr); static inline void tb_set_jmp_target(TranslationBlock *tb, int n, uintptr_t addr) { - uint16_t offset = tb->tb_jmp_offset[n]; + uint16_t offset = tb->jmp_insn_offset[n]; tb_set_jmp_target1((uintptr_t)(tb->tc_ptr + offset), addr); } @@ -350,7 +362,7 @@ static inline void tb_set_jmp_target(TranslationBlock *tb, static inline void tb_set_jmp_target(TranslationBlock *tb, int n, uintptr_t addr) { - tb->tb_next[n] = addr; + tb->jmp_target_addr[n] = addr; } #endif @@ -359,7 +371,7 @@ static inline void tb_add_jump(TranslationBlock *tb, int n, TranslationBlock *tb_next) { /* NOTE: this test is only needed for thread safety */ - if (!tb->jmp_next[n]) { + if (!tb->jmp_list_next[n]) { qemu_log_mask_and_addr(CPU_LOG_EXEC, tb->pc, "Linking TBs %p [" TARGET_FMT_lx "] index %d -> %p [" TARGET_FMT_lx "]\n", @@ -369,8 +381,8 @@ static inline void tb_add_jump(TranslationBlock *tb, int n, tb_set_jmp_target(tb, n, (uintptr_t)tb_next->tc_ptr); /* add in TB jmp circular list */ - tb->jmp_next[n] = tb_next->jmp_first; - tb_next->jmp_first = (TranslationBlock *)((uintptr_t)(tb) | (n)); + tb->jmp_list_next[n] = tb_next->jmp_list_first; + tb_next->jmp_list_first = (TranslationBlock *)((uintptr_t)tb | n); } } |