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Diffstat (limited to 'arch/ia64/kernel/gate.S')
| -rw-r--r-- | arch/ia64/kernel/gate.S | 380 |
1 files changed, 0 insertions, 380 deletions
diff --git a/arch/ia64/kernel/gate.S b/arch/ia64/kernel/gate.S deleted file mode 100644 index 9f235cd551..0000000000 --- a/arch/ia64/kernel/gate.S +++ /dev/null @@ -1,380 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -/* - * This file contains the code that gets mapped at the upper end of each task's text - * region. For now, it contains the signal trampoline code only. - * - * Copyright (C) 1999-2003 Hewlett-Packard Co - * David Mosberger-Tang <davidm@hpl.hp.com> - */ - - -#include <asm/asmmacro.h> -#include <asm/errno.h> -#include <asm/asm-offsets.h> -#include <asm/sigcontext.h> -#include <asm/unistd.h> -#include <asm/kregs.h> -#include <asm/page.h> -#include <asm/native/inst.h> - -/* - * We can't easily refer to symbols inside the kernel. To avoid full runtime relocation, - * complications with the linker (which likes to create PLT stubs for branches - * to targets outside the shared object) and to avoid multi-phase kernel builds, we - * simply create minimalistic "patch lists" in special ELF sections. - */ - .section ".data..patch.fsyscall_table", "a" - .previous -#define LOAD_FSYSCALL_TABLE(reg) \ -[1:] movl reg=0; \ - .xdata4 ".data..patch.fsyscall_table", 1b-. - - .section ".data..patch.brl_fsys_bubble_down", "a" - .previous -#define BRL_COND_FSYS_BUBBLE_DOWN(pr) \ -[1:](pr)brl.cond.sptk 0; \ - ;; \ - .xdata4 ".data..patch.brl_fsys_bubble_down", 1b-. - -GLOBAL_ENTRY(__kernel_syscall_via_break) - .prologue - .altrp b6 - .body - /* - * Note: for (fast) syscall restart to work, the break instruction must be - * the first one in the bundle addressed by syscall_via_break. - */ -{ .mib - break 0x100000 - nop.i 0 - br.ret.sptk.many b6 -} -END(__kernel_syscall_via_break) - -# define ARG0_OFF (16 + IA64_SIGFRAME_ARG0_OFFSET) -# define ARG1_OFF (16 + IA64_SIGFRAME_ARG1_OFFSET) -# define ARG2_OFF (16 + IA64_SIGFRAME_ARG2_OFFSET) -# define SIGHANDLER_OFF (16 + IA64_SIGFRAME_HANDLER_OFFSET) -# define SIGCONTEXT_OFF (16 + IA64_SIGFRAME_SIGCONTEXT_OFFSET) - -# define FLAGS_OFF IA64_SIGCONTEXT_FLAGS_OFFSET -# define CFM_OFF IA64_SIGCONTEXT_CFM_OFFSET -# define FR6_OFF IA64_SIGCONTEXT_FR6_OFFSET -# define BSP_OFF IA64_SIGCONTEXT_AR_BSP_OFFSET -# define RNAT_OFF IA64_SIGCONTEXT_AR_RNAT_OFFSET -# define UNAT_OFF IA64_SIGCONTEXT_AR_UNAT_OFFSET -# define FPSR_OFF IA64_SIGCONTEXT_AR_FPSR_OFFSET -# define PR_OFF IA64_SIGCONTEXT_PR_OFFSET -# define RP_OFF IA64_SIGCONTEXT_IP_OFFSET -# define SP_OFF IA64_SIGCONTEXT_R12_OFFSET -# define RBS_BASE_OFF IA64_SIGCONTEXT_RBS_BASE_OFFSET -# define LOADRS_OFF IA64_SIGCONTEXT_LOADRS_OFFSET -# define base0 r2 -# define base1 r3 - /* - * When we get here, the memory stack looks like this: - * - * +===============================+ - * | | - * // struct sigframe // - * | | - * +-------------------------------+ <-- sp+16 - * | 16 byte of scratch | - * | space | - * +-------------------------------+ <-- sp - * - * The register stack looks _exactly_ the way it looked at the time the signal - * occurred. In other words, we're treading on a potential mine-field: each - * incoming general register may be a NaT value (including sp, in which case the - * process ends up dying with a SIGSEGV). - * - * The first thing need to do is a cover to get the registers onto the backing - * store. Once that is done, we invoke the signal handler which may modify some - * of the machine state. After returning from the signal handler, we return - * control to the previous context by executing a sigreturn system call. A signal - * handler may call the rt_sigreturn() function to directly return to a given - * sigcontext. However, the user-level sigreturn() needs to do much more than - * calling the rt_sigreturn() system call as it needs to unwind the stack to - * restore preserved registers that may have been saved on the signal handler's - * call stack. - */ - -#define SIGTRAMP_SAVES \ - .unwabi 3, 's'; /* mark this as a sigtramp handler (saves scratch regs) */ \ - .unwabi @svr4, 's'; /* backwards compatibility with old unwinders (remove in v2.7) */ \ - .savesp ar.unat, UNAT_OFF+SIGCONTEXT_OFF; \ - .savesp ar.fpsr, FPSR_OFF+SIGCONTEXT_OFF; \ - .savesp pr, PR_OFF+SIGCONTEXT_OFF; \ - .savesp rp, RP_OFF+SIGCONTEXT_OFF; \ - .savesp ar.pfs, CFM_OFF+SIGCONTEXT_OFF; \ - .vframesp SP_OFF+SIGCONTEXT_OFF - -GLOBAL_ENTRY(__kernel_sigtramp) - // describe the state that is active when we get here: - .prologue - SIGTRAMP_SAVES - .body - - .label_state 1 - - adds base0=SIGHANDLER_OFF,sp - adds base1=RBS_BASE_OFF+SIGCONTEXT_OFF,sp - br.call.sptk.many rp=1f -1: - ld8 r17=[base0],(ARG0_OFF-SIGHANDLER_OFF) // get pointer to signal handler's plabel - ld8 r15=[base1] // get address of new RBS base (or NULL) - cover // push args in interrupted frame onto backing store - ;; - cmp.ne p1,p0=r15,r0 // do we need to switch rbs? (note: pr is saved by kernel) - mov.m r9=ar.bsp // fetch ar.bsp - .spillsp.p p1, ar.rnat, RNAT_OFF+SIGCONTEXT_OFF -(p1) br.cond.spnt setup_rbs // yup -> (clobbers p8, r14-r16, and r18-r20) -back_from_setup_rbs: - alloc r8=ar.pfs,0,0,3,0 - ld8 out0=[base0],16 // load arg0 (signum) - adds base1=(ARG1_OFF-(RBS_BASE_OFF+SIGCONTEXT_OFF)),base1 - ;; - ld8 out1=[base1] // load arg1 (siginfop) - ld8 r10=[r17],8 // get signal handler entry point - ;; - ld8 out2=[base0] // load arg2 (sigcontextp) - ld8 gp=[r17] // get signal handler's global pointer - adds base0=(BSP_OFF+SIGCONTEXT_OFF),sp - ;; - .spillsp ar.bsp, BSP_OFF+SIGCONTEXT_OFF - st8 [base0]=r9 // save sc_ar_bsp - adds base0=(FR6_OFF+SIGCONTEXT_OFF),sp - adds base1=(FR6_OFF+16+SIGCONTEXT_OFF),sp - ;; - stf.spill [base0]=f6,32 - stf.spill [base1]=f7,32 - ;; - stf.spill [base0]=f8,32 - stf.spill [base1]=f9,32 - mov b6=r10 - ;; - stf.spill [base0]=f10,32 - stf.spill [base1]=f11,32 - ;; - stf.spill [base0]=f12,32 - stf.spill [base1]=f13,32 - ;; - stf.spill [base0]=f14,32 - stf.spill [base1]=f15,32 - br.call.sptk.many rp=b6 // call the signal handler -.ret0: adds base0=(BSP_OFF+SIGCONTEXT_OFF),sp - ;; - ld8 r15=[base0] // fetch sc_ar_bsp - mov r14=ar.bsp - ;; - cmp.ne p1,p0=r14,r15 // do we need to restore the rbs? -(p1) br.cond.spnt restore_rbs // yup -> (clobbers r14-r18, f6 & f7) - ;; -back_from_restore_rbs: - adds base0=(FR6_OFF+SIGCONTEXT_OFF),sp - adds base1=(FR6_OFF+16+SIGCONTEXT_OFF),sp - ;; - ldf.fill f6=[base0],32 - ldf.fill f7=[base1],32 - ;; - ldf.fill f8=[base0],32 - ldf.fill f9=[base1],32 - ;; - ldf.fill f10=[base0],32 - ldf.fill f11=[base1],32 - ;; - ldf.fill f12=[base0],32 - ldf.fill f13=[base1],32 - ;; - ldf.fill f14=[base0],32 - ldf.fill f15=[base1],32 - mov r15=__NR_rt_sigreturn - .restore sp // pop .prologue - break __BREAK_SYSCALL - - .prologue - SIGTRAMP_SAVES -setup_rbs: - mov ar.rsc=0 // put RSE into enforced lazy mode - ;; - .save ar.rnat, r19 - mov r19=ar.rnat // save RNaT before switching backing store area - adds r14=(RNAT_OFF+SIGCONTEXT_OFF),sp - - mov r18=ar.bspstore - mov ar.bspstore=r15 // switch over to new register backing store area - ;; - - .spillsp ar.rnat, RNAT_OFF+SIGCONTEXT_OFF - st8 [r14]=r19 // save sc_ar_rnat - .body - mov.m r16=ar.bsp // sc_loadrs <- (new bsp - new bspstore) << 16 - adds r14=(LOADRS_OFF+SIGCONTEXT_OFF),sp - ;; - invala - sub r15=r16,r15 - extr.u r20=r18,3,6 - ;; - mov ar.rsc=0xf // set RSE into eager mode, pl 3 - cmp.eq p8,p0=63,r20 - shl r15=r15,16 - ;; - st8 [r14]=r15 // save sc_loadrs -(p8) st8 [r18]=r19 // if bspstore points at RNaT slot, store RNaT there now - .restore sp // pop .prologue - br.cond.sptk back_from_setup_rbs - - .prologue - SIGTRAMP_SAVES - .spillsp ar.rnat, RNAT_OFF+SIGCONTEXT_OFF - .body -restore_rbs: - // On input: - // r14 = bsp1 (bsp at the time of return from signal handler) - // r15 = bsp0 (bsp at the time the signal occurred) - // - // Here, we need to calculate bspstore0, the value that ar.bspstore needs - // to be set to, based on bsp0 and the size of the dirty partition on - // the alternate stack (sc_loadrs >> 16). This can be done with the - // following algorithm: - // - // bspstore0 = rse_skip_regs(bsp0, -rse_num_regs(bsp1 - (loadrs >> 19), bsp1)); - // - // This is what the code below does. - // - alloc r2=ar.pfs,0,0,0,0 // alloc null frame - adds r16=(LOADRS_OFF+SIGCONTEXT_OFF),sp - adds r18=(RNAT_OFF+SIGCONTEXT_OFF),sp - ;; - ld8 r17=[r16] - ld8 r16=[r18] // get new rnat - extr.u r18=r15,3,6 // r18 <- rse_slot_num(bsp0) - ;; - mov ar.rsc=r17 // put RSE into enforced lazy mode - shr.u r17=r17,16 - ;; - sub r14=r14,r17 // r14 (bspstore1) <- bsp1 - (sc_loadrs >> 16) - shr.u r17=r17,3 // r17 <- (sc_loadrs >> 19) - ;; - loadrs // restore dirty partition - extr.u r14=r14,3,6 // r14 <- rse_slot_num(bspstore1) - ;; - add r14=r14,r17 // r14 <- rse_slot_num(bspstore1) + (sc_loadrs >> 19) - ;; - shr.u r14=r14,6 // r14 <- (rse_slot_num(bspstore1) + (sc_loadrs >> 19))/0x40 - ;; - sub r14=r14,r17 // r14 <- -rse_num_regs(bspstore1, bsp1) - movl r17=0x8208208208208209 - ;; - add r18=r18,r14 // r18 (delta) <- rse_slot_num(bsp0) - rse_num_regs(bspstore1,bsp1) - setf.sig f7=r17 - cmp.lt p7,p0=r14,r0 // p7 <- (r14 < 0)? - ;; -(p7) adds r18=-62,r18 // delta -= 62 - ;; - setf.sig f6=r18 - ;; - xmpy.h f6=f6,f7 - ;; - getf.sig r17=f6 - ;; - add r17=r17,r18 - shr r18=r18,63 - ;; - shr r17=r17,5 - ;; - sub r17=r17,r18 // r17 = delta/63 - ;; - add r17=r14,r17 // r17 <- delta/63 - rse_num_regs(bspstore1, bsp1) - ;; - shladd r15=r17,3,r15 // r15 <- bsp0 + 8*(delta/63 - rse_num_regs(bspstore1, bsp1)) - ;; - mov ar.bspstore=r15 // switch back to old register backing store area - ;; - mov ar.rnat=r16 // restore RNaT - mov ar.rsc=0xf // (will be restored later on from sc_ar_rsc) - // invala not necessary as that will happen when returning to user-mode - br.cond.sptk back_from_restore_rbs -END(__kernel_sigtramp) - -/* - * On entry: - * r11 = saved ar.pfs - * r15 = system call # - * b0 = saved return address - * b6 = return address - * On exit: - * r11 = saved ar.pfs - * r15 = system call # - * b0 = saved return address - * all other "scratch" registers: undefined - * all "preserved" registers: same as on entry - */ - -GLOBAL_ENTRY(__kernel_syscall_via_epc) - .prologue - .altrp b6 - .body -{ - /* - * Note: the kernel cannot assume that the first two instructions in this - * bundle get executed. The remaining code must be safe even if - * they do not get executed. - */ - adds r17=-1024,r15 // A - mov r10=0 // A default to successful syscall execution - epc // B causes split-issue -} - ;; - RSM_PSR_BE_I(r20, r22) // M2 (5 cyc to srlz.d) - LOAD_FSYSCALL_TABLE(r14) // X - ;; - mov r16=IA64_KR(CURRENT) // M2 (12 cyc) - shladd r18=r17,3,r14 // A - mov r19=NR_syscalls-1 // A - ;; - lfetch [r18] // M0|1 - MOV_FROM_PSR(p0, r29, r8) // M2 (12 cyc) - // If r17 is a NaT, p6 will be zero - cmp.geu p6,p7=r19,r17 // A (sysnr > 0 && sysnr < 1024+NR_syscalls)? - ;; - mov r21=ar.fpsr // M2 (12 cyc) - tnat.nz p10,p9=r15 // I0 - mov.i r26=ar.pfs // I0 (would stall anyhow due to srlz.d...) - ;; - srlz.d // M0 (forces split-issue) ensure PSR.BE==0 -(p6) ld8 r18=[r18] // M0|1 - nop.i 0 - ;; - nop.m 0 -(p6) tbit.z.unc p8,p0=r18,0 // I0 (dual-issues with "mov b7=r18"!) - nop.i 0 - ;; - SSM_PSR_I(p8, p14, r25) -(p6) mov b7=r18 // I0 -(p8) br.dptk.many b7 // B - - mov r27=ar.rsc // M2 (12 cyc) -/* - * brl.cond doesn't work as intended because the linker would convert this branch - * into a branch to a PLT. Perhaps there will be a way to avoid this with some - * future version of the linker. In the meantime, we just use an indirect branch - * instead. - */ -#ifdef CONFIG_ITANIUM -(p6) add r14=-8,r14 // r14 <- addr of fsys_bubble_down entry - ;; -(p6) ld8 r14=[r14] // r14 <- fsys_bubble_down - ;; -(p6) mov b7=r14 -(p6) br.sptk.many b7 -#else - BRL_COND_FSYS_BUBBLE_DOWN(p6) -#endif - SSM_PSR_I(p0, p14, r10) - mov r10=-1 -(p10) mov r8=EINVAL -(p9) mov r8=ENOSYS - FSYS_RETURN - -END(__kernel_syscall_via_epc) |