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kc3-lang/libffi/src/xtensa/sysv.S
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Author :
Max Filippov
Date : 2022-02-20 16:01:38
Hash : ab167710
Message : Xtensa cleanups and XEA3 support (#677) * xtensa: clean up stack usage in ffi_trampoline call Space for outgoing call arguments reserved in the stack frame of the function ffi_trampoline overlaps register spill overflow area at the top of the frame. In xtensa XEA2 exception architecture the layout of overlapping areas is identical so that even if the ffi_trampoline registers frame gets spilled the memory contents doesn't change. This is not so with the xtensa XEA3 exception architecture, where registers a0 - a7 of a different function are spilled in that location. Reserve spill area for 8 registers to avoid overlapping of the spill area with the outgoing call arguments area in the ffi_trampoline. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> * xtensa: support xtensa XEA3 exception architecture XEA3 requires that 32 bytes of register spill area is reserved in all functions. Fix ffi_cacheflush entry instruction to satisfy this requirement. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> * xtensa: maintain stack alignment xtensa ABI requires stack alignment on 16 byte boundary and passing up to 6 arguments in registers. To simplify stack alignment maintenance fixed amount of stack space is reserved for arguments passed in registers and variable but correctly aligned amount is reserved for the remaining arguments. After copying arguments to the stack and loading registers the fixed part of the stack reservation is freed. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> * xtensa: fix err_bad_abi tests Check ffi_cif::abi value in the ffi_prep_closure_loc and return FFI_BAD_ABI error if it's not one of the supported values. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
- src/xtensa/sysv.S
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/* ----------------------------------------------------------------------- sysv.S - Copyright (c) 2013 Tensilica, Inc. XTENSA Foreign Function Interface Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the ``Software''), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED ``AS IS'', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. ----------------------------------------------------------------------- */ #define LIBFFI_ASM #include <fficonfig.h> #include <ffi.h> #define ENTRY(name) .text; .globl name; .type name,@function; .align 4; name: #define END(name) .size name , . - name /* Assert that the table below is in sync with ffi.h. */ #if FFI_TYPE_UINT8 != 5 \ || FFI_TYPE_SINT8 != 6 \ || FFI_TYPE_UINT16 != 7 \ || FFI_TYPE_SINT16 != 8 \ || FFI_TYPE_UINT32 != 9 \ || FFI_TYPE_SINT32 != 10 \ || FFI_TYPE_UINT64 != 11 #error "xtensa/sysv.S out of sync with ffi.h" #endif #define FFI_REGISTER_ARGS_OFFSET ((XTENSA_STACK_ALIGNMENT - \ FFI_REGISTER_NARGS * 4) & \ (XTENSA_STACK_ALIGNMENT - 1)) /* ffi_call_SYSV (rvalue, rbytes, flags, (*fnaddr)(), bytes, ecif) void *rvalue; a2 unsigned long rbytes; a3 unsigned flags; a4 void (*fnaddr)(); a5 unsigned long bytes; a6 extended_cif* ecif) a7 */ ENTRY(ffi_call_SYSV) entry a1, 32 # 32 byte frame for using call8 below mov a10, a7 # a10(->arg0): ecif sub a11, a1, a6 # a11(->arg1): stack pointer mov a7, a1 # fp movsp a1, a11 # set new sp = old_sp - bytes # align ffi_prep_args stack argument so that arguments # passed on stack if any start on 16-byte aligned boundary addi a11, a11, FFI_REGISTER_ARGS_OFFSET movi a8, ffi_prep_args callx8 a8 # ffi_prep_args(ecif, stack) # prepare to move stack pointer back # to point to arguments passed on stack addi a6, a1, FFI_REGISTER_ARGS_SPACE # we can pass up to 6 arguments in registers # for simplicity, just load 6 arguments l32i a10, a1, FFI_REGISTER_ARGS_OFFSET + 0 l32i a11, a1, FFI_REGISTER_ARGS_OFFSET + 4 l32i a12, a1, FFI_REGISTER_ARGS_OFFSET + 8 l32i a13, a1, FFI_REGISTER_ARGS_OFFSET + 12 l32i a14, a1, FFI_REGISTER_ARGS_OFFSET + 16 l32i a15, a1, FFI_REGISTER_ARGS_OFFSET + 20 # move stack pointer movsp a1, a6 callx8 a5 # (*fn)(args...) # Handle return value(s) beqz a2, .Lexit movi a5, FFI_TYPE_STRUCT bne a4, a5, .Lstore movi a5, 16 blt a5, a3, .Lexit s32i a10, a2, 0 blti a3, 5, .Lexit addi a3, a3, -1 s32i a11, a2, 4 blti a3, 8, .Lexit s32i a12, a2, 8 blti a3, 12, .Lexit s32i a13, a2, 12 .Lexit: retw .Lstore: addi a4, a4, -FFI_TYPE_UINT8 bgei a4, 7, .Lexit # should never happen movi a6, store_calls add a4, a4, a4 addx4 a6, a4, a6 # store_table + idx * 8 jx a6 .align 8 store_calls: # UINT8 s8i a10, a2, 0 retw # SINT8 .align 8 s8i a10, a2, 0 retw # UINT16 .align 8 s16i a10, a2, 0 retw # SINT16 .align 8 s16i a10, a2, 0 retw # UINT32 .align 8 s32i a10, a2, 0 retw # SINT32 .align 8 s32i a10, a2, 0 retw # UINT64 .align 8 s32i a10, a2, 0 s32i a11, a2, 4 retw END(ffi_call_SYSV) /* * void ffi_cacheflush (unsigned long start, unsigned long end) */ #define EXTRA_ARGS_SIZE 24 ENTRY(ffi_cacheflush) entry a1, 32 1: #if XCHAL_DCACHE_SIZE dhwbi a2, 0 #endif #if XCHAL_ICACHE_SIZE ihi a2, 0 #endif addi a2, a2, 4 blt a2, a3, 1b retw END(ffi_cacheflush) /* ffi_trampoline is copied to the stack */ ENTRY(ffi_trampoline) /* 32 bytes for spill + spill overflow area of a frame that uses call8, FFI_REGISTER_NARGS * 4 bytes for arguments passed in registers, aligned up to 4 to maintain 16 byte stack alignment, 4 * 4 bytes for the result. This size must be in sync with ffi_closure_SYSV_inner logic. */ entry a1, 32 + FFI_REGISTER_ARGS_SPACE + (4 * 4) # [ 0] j 2f # [ 3] .align 4 # [ 6] 1: .long 0 # [ 8] 2: l32r a15, 1b # [12] _mov a14, a0 # [15] callx0 a15 # [18] # [21] END(ffi_trampoline) /* * ffi_closure() * * a0: closure + 21 * a14: return address (a0) */ ENTRY(ffi_closure_SYSV) /* intentionally omitting entry here */ # restore return address (a0) and move pointer to closure to a10 addi a10, a0, -21 mov a0, a14 # allow up to 4 arguments as return values addi a11, a1, 4 * 4 # save up to 6 arguments to stack (allocated by entry below) s32i a2, a11, 0 s32i a3, a11, 4 s32i a4, a11, 8 s32i a5, a11, 12 s32i a6, a11, 16 s32i a7, a11, 20 movi a8, ffi_closure_SYSV_inner mov a12, a1 callx8 a8 # .._inner(*closure, **avalue, *rvalue) # load up to four return arguments l32i a2, a1, 0 l32i a3, a1, 4 l32i a4, a1, 8 l32i a5, a1, 12 # (sign-)extend return value movi a11, FFI_TYPE_UINT8 bne a10, a11, 1f extui a2, a2, 0, 8 retw 1: movi a11, FFI_TYPE_SINT8 bne a10, a11, 1f sext a2, a2, 7 retw 1: movi a11, FFI_TYPE_UINT16 bne a10, a11, 1f extui a2, a2, 0, 16 retw 1: movi a11, FFI_TYPE_SINT16 bne a10, a11, 1f sext a2, a2, 15 1: retw END(ffi_closure_SYSV)