accel/tcg: re-factor non-RAM execution code

There is no real need to use CF_NOCACHE here. As long as the TB isn't
linked to other TBs or included in the QHT or jump cache then it will
only get executed once.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210213130325.14781-19-alex.bennee@linaro.org>
This commit is contained in:
Alex Bennée 2021-02-13 13:03:20 +00:00
parent a11bbb6a23
commit 873d64ac30

View File

@ -1779,7 +1779,8 @@ static inline void tb_page_add(PageDesc *p, TranslationBlock *tb,
#endif
}
/* add a new TB and link it to the physical page tables. phys_page2 is
/*
* Add a new TB and link it to the physical page tables. phys_page2 is
* (-1) to indicate that only one page contains the TB.
*
* Called with mmap_lock held for user-mode emulation.
@ -1798,17 +1799,6 @@ tb_link_page(TranslationBlock *tb, tb_page_addr_t phys_pc,
assert_memory_lock();
if (phys_pc == -1) {
/*
* If the TB is not associated with a physical RAM page then
* it must be a temporary one-insn TB, and we have nothing to do
* except fill in the page_addr[] fields.
*/
assert(tb->cflags & CF_NOCACHE);
tb->page_addr[0] = tb->page_addr[1] = -1;
return tb;
}
/*
* Add the TB to the page list, acquiring first the pages's locks.
* We keep the locks held until after inserting the TB in the hash table,
@ -1881,9 +1871,8 @@ TranslationBlock *tb_gen_code(CPUState *cpu,
phys_pc = get_page_addr_code(env, pc);
if (phys_pc == -1) {
/* Generate a temporary TB with 1 insn in it */
cflags &= ~CF_COUNT_MASK;
cflags |= CF_NOCACHE | 1;
/* Generate a one-shot TB with 1 insn in it */
cflags = (cflags & ~CF_COUNT_MASK) | 1;
}
cflags &= ~CF_CLUSTER_MASK;
@ -2097,6 +2086,17 @@ TranslationBlock *tb_gen_code(CPUState *cpu,
tb_reset_jump(tb, 1);
}
/*
* If the TB is not associated with a physical RAM page then
* it must be a temporary one-insn TB, and we have nothing to do
* except fill in the page_addr[] fields. Return early before
* attempting to link to other TBs or add to the lookup table.
*/
if (phys_pc == -1) {
tb->page_addr[0] = tb->page_addr[1] = -1;
return tb;
}
/* check next page if needed */
virt_page2 = (pc + tb->size - 1) & TARGET_PAGE_MASK;
phys_page2 = -1;