From 222f23f508a8d778f56eddef14752dfd26d225b4 Mon Sep 17 00:00:00 2001 From: "Dr. David Alan Gilbert" Date: Mon, 12 Dec 2011 16:37:31 +0100 Subject: tcg/arm: remove fixed map code buffer restriction On ARM, don't map the code buffer at a fixed location, and fix up the call/goto tcg routines to let it do long jumps. Mapping the code buffer at a fixed address could sometimes result in it being mapped over the top of the heap with pretty random results. Signed-off-by: Dr. David Alan Gilbert Signed-off-by: Andrzej Zaborowski --- exec.c | 4 +--- tcg/arm/tcg-target.c | 31 ++++++++++++------------------- 2 files changed, 13 insertions(+), 22 deletions(-) diff --git a/exec.c b/exec.c index d8b2180170..4f79cbb27e 100644 --- a/exec.c +++ b/exec.c @@ -497,9 +497,7 @@ static void code_gen_alloc(unsigned long tb_size) if (code_gen_buffer_size > (512 * 1024 * 1024)) code_gen_buffer_size = (512 * 1024 * 1024); #elif defined(__arm__) - /* Map the buffer below 32M, so we can use direct calls and branches */ - flags |= MAP_FIXED; - start = (void *) 0x01000000UL; + /* Keep the buffer no bigger than 16GB to branch between blocks */ if (code_gen_buffer_size > 16 * 1024 * 1024) code_gen_buffer_size = 16 * 1024 * 1024; #elif defined(__s390x__) diff --git a/tcg/arm/tcg-target.c b/tcg/arm/tcg-target.c index e05a64f75c..1d327984e0 100644 --- a/tcg/arm/tcg-target.c +++ b/tcg/arm/tcg-target.c @@ -842,6 +842,12 @@ static inline void tcg_out_st8(TCGContext *s, int cond, tcg_out_st8_12(s, cond, rd, rn, offset); } +/* The _goto case is normally between TBs within the same code buffer, + * and with the code buffer limited to 16GB we shouldn't need the long + * case. + * + * .... except to the prologue that is in its own buffer. + */ static inline void tcg_out_goto(TCGContext *s, int cond, uint32_t addr) { int32_t val; @@ -855,22 +861,20 @@ static inline void tcg_out_goto(TCGContext *s, int cond, uint32_t addr) if (val - 8 < 0x01fffffd && val - 8 > -0x01fffffd) tcg_out_b(s, cond, val); else { -#if 1 - tcg_abort(); -#else if (cond == COND_AL) { tcg_out_ld32_12(s, COND_AL, TCG_REG_PC, TCG_REG_PC, -4); - tcg_out32(s, addr); /* XXX: This is l->u.value, can we use it? */ + tcg_out32(s, addr); } else { tcg_out_movi32(s, cond, TCG_REG_R8, val - 8); tcg_out_dat_reg(s, cond, ARITH_ADD, TCG_REG_PC, TCG_REG_PC, TCG_REG_R8, SHIFT_IMM_LSL(0)); } -#endif } } +/* The call case is mostly used for helpers - so it's not unreasonable + * for them to be beyond branch range */ static inline void tcg_out_call(TCGContext *s, uint32_t addr) { int32_t val; @@ -887,20 +891,9 @@ static inline void tcg_out_call(TCGContext *s, uint32_t addr) tcg_out_bl(s, COND_AL, val); } } else { -#if 1 - tcg_abort(); -#else - if (cond == COND_AL) { - tcg_out_dat_imm(s, cond, ARITH_ADD, TCG_REG_R14, TCG_REG_PC, 4); - tcg_out_ld32_12(s, COND_AL, TCG_REG_PC, TCG_REG_PC, -4); - tcg_out32(s, addr); /* XXX: This is l->u.value, can we use it? */ - } else { - tcg_out_movi32(s, cond, TCG_REG_R9, addr); - tcg_out_dat_reg(s, cond, ARITH_MOV, TCG_REG_R14, 0, - TCG_REG_PC, SHIFT_IMM_LSL(0)); - tcg_out_bx(s, cond, TCG_REG_R9); - } -#endif + tcg_out_dat_imm(s, COND_AL, ARITH_ADD, TCG_REG_R14, TCG_REG_PC, 4); + tcg_out_ld32_12(s, COND_AL, TCG_REG_PC, TCG_REG_PC, -4); + tcg_out32(s, addr); } } -- cgit v1.2.1