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| author | Andrew Waterman <andrew@sifive.com> | 2017-10-23 23:38:41 -0700 |
|---|---|---|
| committer | Andrew Waterman <andrew@sifive.com> | 2017-10-23 23:38:41 -0700 |
| commit | 18087efa98d77918d55127c3d7745cd6d6d9d77b (patch) | |
| tree | 8506d286ac435342ccb4b6d8fad88aa08facbebb | |
| parent | 4c64de3213e7a08e4097970b26a14ad835cabfab (diff) | |
| download | riscv-pk-18087efa98d77918d55127c3d7745cd6d6d9d77b.zip riscv-pk-18087efa98d77918d55127c3d7745cd6d6d9d77b.tar.gz riscv-pk-18087efa98d77918d55127c3d7745cd6d6d9d77b.tar.bz2 | |
Make 4-byte aligned instruction-emulation loads atomic
Per the Unix-class platform spec
| -rw-r--r-- | machine/unprivileged_memory.h | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/machine/unprivileged_memory.h b/machine/unprivileged_memory.h index 787f5f8..5cf2727 100644 --- a/machine/unprivileged_memory.h +++ b/machine/unprivileged_memory.h @@ -76,16 +76,25 @@ static uintptr_t __attribute__((always_inline)) get_insn(uintptr_t mepc, uintptr #else uintptr_t rvc_mask = 3, tmp; asm ("csrrs %[mstatus], mstatus, %[mprv]\n" + "and %[tmp], %[addr], 2\n" + "bnez %[tmp], 1f\n" + STR(LWU) " %[insn], (%[addr])\n" + "and %[tmp], %[insn], %[rvc_mask]\n" + "beq %[tmp], %[rvc_mask], 2f\n" + "sll %[insn], %[insn], %[xlen_minus_16]\n" + "srl %[insn], %[insn], %[xlen_minus_16]\n" + "j 2f\n" + "1:\n" "lhu %[insn], (%[addr])\n" "and %[tmp], %[insn], %[rvc_mask]\n" - "bne %[tmp], %[rvc_mask], 1f\n" + "bne %[tmp], %[rvc_mask], 2f\n" "lhu %[tmp], 2(%[addr])\n" "sll %[tmp], %[tmp], 16\n" "add %[insn], %[insn], %[tmp]\n" - "1: csrw mstatus, %[mstatus]" + "2: csrw mstatus, %[mstatus]" : [mstatus] "+&r" (__mstatus), [insn] "=&r" (val), [tmp] "=&r" (tmp) : [mprv] "r" (MSTATUS_MPRV | MSTATUS_MXR), [addr] "r" (__mepc), - [rvc_mask] "r" (rvc_mask)); + [rvc_mask] "r" (rvc_mask), [xlen_minus_16] "i" (__riscv_xlen - 16)); #endif *mstatus = __mstatus; return val; |