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Diffstat (limited to 'ports/sysdeps/tile/dl-trampoline.S')
| -rw-r--r-- | ports/sysdeps/tile/dl-trampoline.S | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/ports/sysdeps/tile/dl-trampoline.S b/ports/sysdeps/tile/dl-trampoline.S new file mode 100644 index 0000000000..3478824957 --- /dev/null +++ b/ports/sysdeps/tile/dl-trampoline.S @@ -0,0 +1,193 @@ +/* Copyright (C) 2011 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Chris Metcalf <cmetcalf@tilera.com>, 2011. + + 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 <arch/abi.h> + +/* This function is called via the PLT header, which is called + from an individual PLT entry. + + At this point we have several values passed in: + + lr: return address to original user code + r28: the tpnt value to pass to _dl_runtime_resolver + r29: the PLT index of the invoked jump table entry. + + We set up a frame entry that looks like this (in int_reg_t units): + + +57: r25 return values from function... + +56: r24 + [...] + +33: r1 + +32: r0 + +31: PLT index + +30: tpnt + +29: stackframe + +28: caller lr + +27: r25 arguments to function... + +26: r24 + [...] + +3: r1 + +2: r0 + +1: standard ABI slot (sp) + +0: standard ABI slot (callee lr) + + The entries from "stackframe" up are only used in _dl_profile_resolve. + We save and restore r0 through r25, rather than the strictly + architected r0 through r9, to support unusual calling conventions; + for example, __tls_get_addr takes r0 and returns r0, but promises + not to clobber r1 through r24 to support its usual fast path. */ + +#define FRAME_SP (1 * REGSIZE) +#define FRAME_REGS (2 * REGSIZE) +#define FRAME_LR (28 * REGSIZE) /* Must follow FRAME_REGS */ +#define FRAME_STACKFRAME (29 * REGSIZE) +#define FRAME_TPNT (30 * REGSIZE) +#define FRAME_INDEX (31 * REGSIZE) +#define FRAME_RETVAL (32 * REGSIZE) + +#define FRAME_SIZE_SMALL (30 * REGSIZE) +#define FRAME_SIZE_LARGE (58 * REGSIZE) + +#define FOR_EACH_REG(f) \ + f(r0); f(r1); f(r2); f(r3); \ + f(r4); f(r5); f(r6); f(r7); \ + f(r8); f(r9); f(r10); f(r11); \ + f(r12); f(r13); f(r14); f(r15); \ + f(r16); f(r17); f(r18); f(r19); \ + f(r20); f(r21); f(r22); f(r23); \ + f(r24); f(r25) + +#define SAVE(REG) { ST r27, REG; ADDI_PTR r27, r27, REGSIZE } +#define RESTORE(REG) { LD REG, r27; ADDI_PTR r27, r27, REGSIZE } + + .macro dl_resolve, name, profile, framesize +.text +.global \name +.hidden \name +/* Note that cpp expands ENTRY(\name) incorrectly. */ +.type \name,@function +.align 8 +\name: + cfi_startproc + { + ST sp, lr + move r26, sp + } + { + ADDLI_PTR sp, sp, -\framesize + ADDLI_PTR r27, sp, FRAME_SP - \framesize + } + cfi_def_cfa_offset (\framesize) + { + ST r27, r26 + ADDI_PTR r27, r27, FRAME_REGS - FRAME_SP + } + FOR_EACH_REG(SAVE) + { + ST r27, lr + ADDLI_PTR r27, sp, FRAME_TPNT + } + cfi_offset (lr, FRAME_LR - \framesize) + .if \profile + { + move r0, r28 /* tpnt value */ + ST r27, r28 + ADDI_PTR r27, r27, FRAME_INDEX - FRAME_TPNT + } + { + move r1, r29 /* PLT index */ + ST r27, r29 + } + { + move r2, lr /* retaddr */ + ADDI_PTR r3, sp, FRAME_REGS /* La_tile_regs pointer */ + } + { + ADDLI_PTR r4, sp, FRAME_STACKFRAME /* framesize pointer */ + jal _dl_profile_fixup + } + ADDLI_PTR r28, sp, FRAME_STACKFRAME + LD_PTR r28, r28 + BGTZ r28, 1f + .else + { + move r0, r28 /* tpnt value 1 */ + move r1, r29 /* PLT index 2 */ + } + jal _dl_fixup + .endif + { + /* Copy aside the return value so we can restore r0 below. */ + move r29, r0 + /* Set up r27 to let us start restoring registers. */ + ADDLI_PTR r27, sp, FRAME_REGS + } + FOR_EACH_REG(RESTORE) + .if \profile + ADDLI_PTR r28, sp, FRAME_STACKFRAME + LD r28, r28 + BGTZ r28, 1f + .endif + { + /* Restore original user return address. */ + LD lr, r27 + /* Pop off our stack frame. */ + ADDLI_PTR sp, sp, \framesize + } + cfi_def_cfa_offset (0) + jr r29 /* Transfer control to freshly loaded code. */ + jrp lr /* Keep backtracer happy. */ + + .if \profile +1: jalr r29 /* Call resolved function. */ + { + ADDLI_PTR r28, sp, FRAME_TPNT + ADDLI_PTR r27, sp, FRAME_RETVAL + } + FOR_EACH_REG(SAVE) + { + LD r0, r28 + ADDI_PTR r28, r28, FRAME_INDEX - FRAME_TPNT + } + { + LD r1, r28 + ADDLI_PTR r2, sp, FRAME_REGS + } + { + ADDLI_PTR r3, sp, FRAME_RETVAL + jal _dl_call_pltexit + } + { + ADDLI_PTR lr, sp, FRAME_LR + ADDLI_PTR r27, sp, FRAME_RETVAL + } + FOR_EACH_REG(RESTORE) + { + LD lr, lr + ADDLI_PTR sp, sp, \framesize + } + jrp lr + .endif +END (\name) + .endm + + dl_resolve _dl_runtime_resolve, 0, FRAME_SIZE_SMALL +#ifndef PROF + dl_resolve _dl_runtime_profile, 1, FRAME_SIZE_LARGE +#endif |