diff options
Diffstat (limited to 'arch/ia64/kernel/gate.S')
| -rw-r--r-- | arch/ia64/kernel/gate.S | 171 |
1 files changed, 90 insertions, 81 deletions
diff --git a/arch/ia64/kernel/gate.S b/arch/ia64/kernel/gate.S index 74b1ccce4e8..cf5e0a105e1 100644 --- a/arch/ia64/kernel/gate.S +++ b/arch/ia64/kernel/gate.S @@ -13,6 +13,7 @@ #include <asm/sigcontext.h> #include <asm/system.h> #include <asm/unistd.h> +#include "paravirt_inst.h" /* * We can't easily refer to symbols inside the kernel. To avoid full runtime relocation, @@ -48,87 +49,6 @@ GLOBAL_ENTRY(__kernel_syscall_via_break) } END(__kernel_syscall_via_break) -/* - * 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 | psr.i // 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 r29=psr // 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 - ;; -(p8) ssm psr.i -(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 - mov r10=-1 -(p10) mov r8=EINVAL -(p9) mov r8=ENOSYS - FSYS_RETURN -END(__kernel_syscall_via_epc) - # define ARG0_OFF (16 + IA64_SIGFRAME_ARG0_OFFSET) # define ARG1_OFF (16 + IA64_SIGFRAME_ARG1_OFFSET) # define ARG2_OFF (16 + IA64_SIGFRAME_ARG2_OFFSET) @@ -374,3 +294,92 @@ restore_rbs: // 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 + +#ifdef CONFIG_PARAVIRT + /* + * padd to make the size of this symbol constant + * independent of paravirtualization. + */ + .align PAGE_SIZE / 8 +#endif +END(__kernel_syscall_via_epc) |