diff options
Diffstat (limited to 'libc/sysdeps/linux/xtensa/swapcontext.S')
| -rw-r--r-- | libc/sysdeps/linux/xtensa/swapcontext.S | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/xtensa/swapcontext.S b/libc/sysdeps/linux/xtensa/swapcontext.S new file mode 100644 index 000000000..a215edc6d --- /dev/null +++ b/libc/sysdeps/linux/xtensa/swapcontext.S @@ -0,0 +1,173 @@ +/* Copyright (C) 2018 - 2022 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <sysdep.h> +#include "ucontext_i.h" + +#if defined(__XTENSA_CALL0_ABI__) +ENTRY(__swapcontext) + s32i a0, a2, MCONTEXT_SC_PC + s32i a1, a2, MCONTEXT_SC_A_0 + 4 + + /* save callee-saved registers in the context */ + s32i a12, a2, MCONTEXT_SC_A_0 + 48 + s32i a13, a2, MCONTEXT_SC_A_0 + 52 + s32i a14, a2, MCONTEXT_SC_A_0 + 56 + s32i a15, a2, MCONTEXT_SC_A_0 + 60 + + mov a12, a3 + mov a13, a2 + + addi a3, a3, UCONTEXT_SIGMASK + addi a4, a2, UCONTEXT_SIGMASK + movi a2, SIG_SETMASK + movi a5, JUMPTARGET (sigprocmask) + callx0 a5 + bnez a2, .Lerror + + mov a2, a12 + l32i a0, a2, MCONTEXT_SC_PC + l32i a1, a2, MCONTEXT_SC_A_0 + 4 + + /* load callee-saved registers from the context */ + l32i a12, a2, MCONTEXT_SC_A_0 + 48 + l32i a13, a2, MCONTEXT_SC_A_0 + 52 + l32i a14, a2, MCONTEXT_SC_A_0 + 56 + l32i a15, a2, MCONTEXT_SC_A_0 + 60 + + movi a2, 0 + ret +.Lerror: + l32i a0, a13, MCONTEXT_SC_PC + l32i a12, a13, MCONTEXT_SC_A_0 + 48 + l32i a13, a13, MCONTEXT_SC_A_0 + 52 + ret +END(__swapcontext) +#elif defined(__XTENSA_WINDOWED_ABI__) +ENTRY(__swapcontext) + movi a4, __window_spill + callx4 a4 + mov a9, a3 + s32i a0, a2, MCONTEXT_SC_PC + + /* copy registers a0..a3 from spill area */ + addi a3, a1, -16 + l32i a4, a3, 0 + l32i a5, a3, 4 + l32i a6, a3, 8 + l32i a7, a3, 12 + s32i a4, a2, MCONTEXT_SC_A_0 + 0 + s32i a5, a2, MCONTEXT_SC_A_0 + 4 + s32i a6, a2, MCONTEXT_SC_A_0 + 8 + s32i a7, a2, MCONTEXT_SC_A_0 + 12 + + /* if it was call4 then register saving is done */ + extui a4, a0, 30, 2 + bltui a4, 2, 1f + + /* otherwise load spill overflow area address into a3 */ + addi a3, a5, -16 + l32i a3, a3, 4 + addi a3, a3, -32 + beqi a4, 2, 2f + + /* copy registers a8..a11 from spill overflow area */ + addi a3, a3, -16 + l32i a4, a3, 16 + l32i a5, a3, 20 + l32i a6, a3, 24 + l32i a7, a3, 28 + s32i a4, a2, MCONTEXT_SC_A_0 + 32 + s32i a5, a2, MCONTEXT_SC_A_0 + 36 + s32i a6, a2, MCONTEXT_SC_A_0 + 40 + s32i a7, a2, MCONTEXT_SC_A_0 + 44 + + /* copy registers a4..a7 from spill overflow area */ +2: + l32i a4, a3, 0 + l32i a5, a3, 4 + l32i a6, a3, 8 + l32i a7, a3, 12 + s32i a4, a2, MCONTEXT_SC_A_0 + 16 + s32i a5, a2, MCONTEXT_SC_A_0 + 20 + s32i a6, a2, MCONTEXT_SC_A_0 + 24 + s32i a7, a2, MCONTEXT_SC_A_0 + 28 +1: + movi a6, SIG_SETMASK + addi a7, a9, UCONTEXT_SIGMASK + addi a8, a2, UCONTEXT_SIGMASK + mov a2, a9 + movi a4, JUMPTARGET (sigprocmask) + callx4 a4 + bnez a6, .Lerror + + l32i a0, a2, MCONTEXT_SC_PC + + /* copy registers a0..a3 to spill area */ + addi a3, a1, -16 + l32i a4, a2, MCONTEXT_SC_A_0 + 0 + l32i a5, a2, MCONTEXT_SC_A_0 + 4 + l32i a6, a2, MCONTEXT_SC_A_0 + 8 + l32i a7, a2, MCONTEXT_SC_A_0 + 12 + s32i a4, a3, 0 + s32i a5, a3, 4 + s32i a6, a3, 8 + s32i a7, a3, 12 + + /* if it was call4 then register setup is done */ + extui a4, a0, 30, 2 + bltui a4, 2, 1f + + /* otherwise load spill overflow area address into a3 */ + addi a3, a5, -16 + l32i a3, a3, 4 + addi a3, a3, -32 + beqi a4, 2, 2f + + /* copy registers a8..a11 to spill overflow area */ + addi a3, a3, -16 + l32i a4, a2, MCONTEXT_SC_A_0 + 32 + l32i a5, a2, MCONTEXT_SC_A_0 + 36 + l32i a6, a2, MCONTEXT_SC_A_0 + 40 + l32i a7, a2, MCONTEXT_SC_A_0 + 44 + s32i a4, a3, 16 + s32i a5, a3, 20 + s32i a6, a3, 24 + s32i a7, a3, 28 + + /* copy registers a4..a7 to spill overflow area */ +2: + l32i a4, a2, MCONTEXT_SC_A_0 + 16 + l32i a5, a2, MCONTEXT_SC_A_0 + 20 + l32i a6, a2, MCONTEXT_SC_A_0 + 24 + l32i a7, a2, MCONTEXT_SC_A_0 + 28 + s32i a4, a3, 0 + s32i a5, a3, 4 + s32i a6, a3, 8 + s32i a7, a3, 12 +1: + movi a2, 0 + retw +.Lerror: + mov a2, a6 + retw +END(__swapcontext) +#else +#error Unsupported Xtensa ABI +#endif + +weak_alias (__swapcontext, swapcontext) |