>From fa0950e403bbb98989117f632215ae0e698457d7 Mon Sep 17 00:00:00 2001 From: Chen Gang <gang.chen.5...@gmail.com> Date: Sun, 4 Oct 2015 17:41:14 +0800 Subject: [PATCH v5] target-tilegx: Support iret instruction and related special registers
Acording to the __longjmp tilegx libc implementation, and reference from tilegx ISA document, and suggested by tilegx architecture member, we can treat iret instruction as "jrp lr". The related code is below: ENTRY (__longjmp) FEEDBACK_ENTER(__longjmp) #define RESTORE(r) { LD r, r0 ; ADDI_PTR r0, r0, REGSIZE } FOR_EACH_CALLEE_SAVED_REG(RESTORE) { LD r2, r0 ; retrieve ICS bit from jmp_buf movei r3, 1 CMPEQI r0, r1, 0 } { mtspr INTERRUPT_CRITICAL_SECTION, r3 shli r2, r2, SPR_EX_CONTEXT_0_1__ICS_SHIFT } { mtspr EX_CONTEXT_0_0, lr ori r2, r2, RETURN_PL } { or r0, r1, r0 mtspr EX_CONTEXT_0_1, r2 } iret jrp lr EX_CONTEXT_0_0 is used for jumping address, and EX_CONTEXT_0_1 is for INTERRUPT_CRITICAL_SECTION, which should only be 0 or 1 in user mode, or it will cause target SEGV (and the patch doesn't implement system mode). iret will "jrp EX_CONTEXT_0_0", for __longjmp, it is lr (but in other cases, it may be not). And the last "jrp lr" in __longjmp is for historical reasons, and might get removed in the future. Signed-off-by: Chen Gang <gang.chen.5...@gmail.com> --- target-tilegx/cpu.h | 2 ++ target-tilegx/helper.c | 22 ++++++++++++++++++++++ target-tilegx/helper.h | 1 + target-tilegx/translate.c | 14 +++++++++++++- 4 files changed, 38 insertions(+), 1 deletion(-) diff --git a/target-tilegx/cpu.h b/target-tilegx/cpu.h index 6f04fe7..6c0fd53 100644 --- a/target-tilegx/cpu.h +++ b/target-tilegx/cpu.h @@ -53,6 +53,8 @@ enum { TILEGX_SPR_CMPEXCH = 0, TILEGX_SPR_CRITICAL_SEC = 1, TILEGX_SPR_SIM_CONTROL = 2, + TILEGX_SPR_EX_CONTEXT_0_0 = 3, + TILEGX_SPR_EX_CONTEXT_0_1 = 4, TILEGX_SPR_COUNT }; diff --git a/target-tilegx/helper.c b/target-tilegx/helper.c index 36b287f..dda821f 100644 --- a/target-tilegx/helper.c +++ b/target-tilegx/helper.c @@ -22,6 +22,7 @@ #include "qemu-common.h" #include "exec/helper-proto.h" #include <zlib.h> /* For crc32 */ +#include "syscall_defs.h" void helper_exception(CPUTLGState *env, uint32_t excp) { @@ -31,6 +32,27 @@ void helper_exception(CPUTLGState *env, uint32_t excp) cpu_loop_exit(cs); } +void helper_ext01_ics(CPUTLGState *env) +{ + uint64_t val = env->spregs[TILEGX_SPR_EX_CONTEXT_0_1]; + + switch (val) { + case 0: + case 1: + env->spregs[TILEGX_SPR_CRITICAL_SEC] = val; + break; + default: +#if defined(CONFIG_USER_ONLY) + env->signo = TARGET_SIGILL; + env->sigcode = TARGET_ILL_ILLOPC; + helper_exception(env, TILEGX_EXCP_SIGNAL); +#else + helper_exception(env, TILEGX_EXCP_OPCODE_UNIMPLEMENTED); +#endif + break; + } +} + uint64_t helper_cntlz(uint64_t arg) { return clz64(arg); diff --git a/target-tilegx/helper.h b/target-tilegx/helper.h index bbcc476..9281d0f 100644 --- a/target-tilegx/helper.h +++ b/target-tilegx/helper.h @@ -1,4 +1,5 @@ DEF_HELPER_2(exception, noreturn, env, i32) +DEF_HELPER_1(ext01_ics, void, env) DEF_HELPER_FLAGS_1(cntlz, TCG_CALL_NO_RWG_SE, i64, i64) DEF_HELPER_FLAGS_1(cnttz, TCG_CALL_NO_RWG_SE, i64, i64) DEF_HELPER_FLAGS_1(pcnt, TCG_CALL_NO_RWG_SE, i64, i64) diff --git a/target-tilegx/translate.c b/target-tilegx/translate.c index ab3fc81..acb9ec4 100644 --- a/target-tilegx/translate.c +++ b/target-tilegx/translate.c @@ -529,6 +529,15 @@ static TileExcp gen_rr_opcode(DisasContext *dc, unsigned opext, /* ??? This should yield, especially in system mode. */ mnemonic = "nap"; goto done0; + case OE_RR_X1(IRET): + gen_helper_ext01_ics(cpu_env); + dc->jmp.cond = TCG_COND_ALWAYS; + dc->jmp.dest = tcg_temp_new(); + tcg_gen_ld_tl(dc->jmp.dest, cpu_env, + offsetof(CPUTLGState, spregs[TILEGX_SPR_EX_CONTEXT_0_0])); + tcg_gen_andi_tl(dc->jmp.dest, dc->jmp.dest, ~7); + mnemonic = "iret"; + goto done0; case OE_RR_X1(SWINT0): case OE_RR_X1(SWINT2): case OE_RR_X1(SWINT3): @@ -606,7 +615,6 @@ static TileExcp gen_rr_opcode(DisasContext *dc, unsigned opext, break; case OE_RR_X0(FSINGLE_PACK1): case OE_RR_Y0(FSINGLE_PACK1): - case OE_RR_X1(IRET): return TILEGX_EXCP_OPCODE_UNIMPLEMENTED; case OE_RR_X1(LD1S): memop = MO_SB; @@ -1947,6 +1955,10 @@ static const TileSPR *find_spr(unsigned spr) offsetof(CPUTLGState, spregs[TILEGX_SPR_CRITICAL_SEC]), 0, 0) D(SIM_CONTROL, offsetof(CPUTLGState, spregs[TILEGX_SPR_SIM_CONTROL]), 0, 0) + D(EX_CONTEXT_0_0, + offsetof(CPUTLGState, spregs[TILEGX_SPR_EX_CONTEXT_0_0]), 0, 0) + D(EX_CONTEXT_0_1, + offsetof(CPUTLGState, spregs[TILEGX_SPR_EX_CONTEXT_0_1]), 0, 0) } #undef D -- 1.9.3
0001-target-tilegx-Support-iret-instruction-and-related-s.patch
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