From 729cc88801a0968e58e2ebab63b50e2f111e5e16 Mon Sep 17 00:00:00 2001 From: jhibbits Date: Sat, 2 Jun 2018 19:17:11 +0000 Subject: [PATCH] Added ptrace support for reading/writing powerpc VSX registers Summary: Added ptrace support for getting/setting the remaining part of the VSX registers (the part that's not already covered by FPR or VR registers). This is necessary to add support for VSX registers in debuggers. Submitted by: Luis Pires Differential Revision: https://reviews.freebsd.org/D15458 --- lib/libc/sys/ptrace.2 | 20 ++++- sys/powerpc/include/fpu.h | 1 + sys/powerpc/include/ptrace.h | 2 + sys/powerpc/powerpc/fpu.c | 116 ++++++++++++++++----------- sys/powerpc/powerpc/ptrace_machdep.c | 42 ++++++++++ 5 files changed, 135 insertions(+), 46 deletions(-) diff --git a/lib/libc/sys/ptrace.2 b/lib/libc/sys/ptrace.2 index 8c6a094a221d..5a1763474223 100644 --- a/lib/libc/sys/ptrace.2 +++ b/lib/libc/sys/ptrace.2 @@ -2,7 +2,7 @@ .\" $NetBSD: ptrace.2,v 1.2 1995/02/27 12:35:37 cgd Exp $ .\" .\" This file is in the public domain. -.Dd May 22, 2018 +.Dd June 2, 2018 .Dt PTRACE 2 .Os .Sh NAME @@ -939,6 +939,24 @@ machine state from the buffer pointed to by The .Fa data argument is ignored. +.It Dv PT_GETVSRREGS +Return doubleword 1 of the thread's +.Dv VSX +registers VSR0-VSR31 in the buffer pointed to by +.Fa addr . +.Pp +The +.Fa data +argument is ignored. +.It Dv PT_SETVSRREGS +Set doubleword 1 of the thread's +.Dv VSX +registers VSR0-VSR31 from the buffer pointed to by +.Fa addr . +.Pp +The +.Fa data +argument is ignored. .El .Pp Additionally, other machine-specific requests can exist. diff --git a/sys/powerpc/include/fpu.h b/sys/powerpc/include/fpu.h index 9d10b116cfbd..1fb07c6cc599 100644 --- a/sys/powerpc/include/fpu.h +++ b/sys/powerpc/include/fpu.h @@ -74,6 +74,7 @@ void enable_fpu(struct thread *); void save_fpu(struct thread *); +void save_fpu_nodrop(struct thread *); #endif /* _KERNEL */ diff --git a/sys/powerpc/include/ptrace.h b/sys/powerpc/include/ptrace.h index 0eb0bc1725ea..4880b1c05f34 100644 --- a/sys/powerpc/include/ptrace.h +++ b/sys/powerpc/include/ptrace.h @@ -39,5 +39,7 @@ #define PT_GETVRREGS (PT_FIRSTMACH + 0) #define PT_SETVRREGS (PT_FIRSTMACH + 1) +#define PT_GETVSRREGS (PT_FIRSTMACH + 2) +#define PT_SETVSRREGS (PT_FIRSTMACH + 3) #endif diff --git a/sys/powerpc/powerpc/fpu.c b/sys/powerpc/powerpc/fpu.c index 932ee07ca57d..c5fa7e1f3987 100644 --- a/sys/powerpc/powerpc/fpu.c +++ b/sys/powerpc/powerpc/fpu.c @@ -45,6 +45,60 @@ __FBSDID("$FreeBSD$"); #include #include +static void +save_fpu_int(struct thread *td) +{ + int msr; + struct pcb *pcb; + + pcb = td->td_pcb; + + /* + * Temporarily re-enable floating-point during the save + */ + msr = mfmsr(); + if (pcb->pcb_flags & PCB_VSX) + mtmsr(msr | PSL_FP | PSL_VSX); + else + mtmsr(msr | PSL_FP); + + /* + * Save the floating-point registers and FPSCR to the PCB + */ + if (pcb->pcb_flags & PCB_VSX) { + #define SFP(n) __asm ("stxvw4x " #n ", 0,%0" \ + :: "b"(&pcb->pcb_fpu.fpr[n])); + SFP(0); SFP(1); SFP(2); SFP(3); + SFP(4); SFP(5); SFP(6); SFP(7); + SFP(8); SFP(9); SFP(10); SFP(11); + SFP(12); SFP(13); SFP(14); SFP(15); + SFP(16); SFP(17); SFP(18); SFP(19); + SFP(20); SFP(21); SFP(22); SFP(23); + SFP(24); SFP(25); SFP(26); SFP(27); + SFP(28); SFP(29); SFP(30); SFP(31); + #undef SFP + } else { + #define SFP(n) __asm ("stfd " #n ", 0(%0)" \ + :: "b"(&pcb->pcb_fpu.fpr[n])); + SFP(0); SFP(1); SFP(2); SFP(3); + SFP(4); SFP(5); SFP(6); SFP(7); + SFP(8); SFP(9); SFP(10); SFP(11); + SFP(12); SFP(13); SFP(14); SFP(15); + SFP(16); SFP(17); SFP(18); SFP(19); + SFP(20); SFP(21); SFP(22); SFP(23); + SFP(24); SFP(25); SFP(26); SFP(27); + SFP(28); SFP(29); SFP(30); SFP(31); + #undef SFP + } + __asm __volatile ("mffs 0; stfd 0,0(%0)" :: "b"(&pcb->pcb_fpu.fpscr)); + + /* + * Disable floating-point again + */ + isync(); + mtmsr(msr); +} + void enable_fpu(struct thread *td) { @@ -129,55 +183,11 @@ enable_fpu(struct thread *td) void save_fpu(struct thread *td) { - int msr; struct pcb *pcb; pcb = td->td_pcb; - /* - * Temporarily re-enable floating-point during the save - */ - msr = mfmsr(); - if (pcb->pcb_flags & PCB_VSX) - mtmsr(msr | PSL_FP | PSL_VSX); - else - mtmsr(msr | PSL_FP); - - /* - * Save the floating-point registers and FPSCR to the PCB - */ - if (pcb->pcb_flags & PCB_VSX) { - #define SFP(n) __asm ("stxvw4x " #n ", 0,%0" \ - :: "b"(&pcb->pcb_fpu.fpr[n])); - SFP(0); SFP(1); SFP(2); SFP(3); - SFP(4); SFP(5); SFP(6); SFP(7); - SFP(8); SFP(9); SFP(10); SFP(11); - SFP(12); SFP(13); SFP(14); SFP(15); - SFP(16); SFP(17); SFP(18); SFP(19); - SFP(20); SFP(21); SFP(22); SFP(23); - SFP(24); SFP(25); SFP(26); SFP(27); - SFP(28); SFP(29); SFP(30); SFP(31); - #undef SFP - } else { - #define SFP(n) __asm ("stfd " #n ", 0(%0)" \ - :: "b"(&pcb->pcb_fpu.fpr[n])); - SFP(0); SFP(1); SFP(2); SFP(3); - SFP(4); SFP(5); SFP(6); SFP(7); - SFP(8); SFP(9); SFP(10); SFP(11); - SFP(12); SFP(13); SFP(14); SFP(15); - SFP(16); SFP(17); SFP(18); SFP(19); - SFP(20); SFP(21); SFP(22); SFP(23); - SFP(24); SFP(25); SFP(26); SFP(27); - SFP(28); SFP(29); SFP(30); SFP(31); - #undef SFP - } - __asm __volatile ("mffs 0; stfd 0,0(%0)" :: "b"(&pcb->pcb_fpu.fpscr)); - - /* - * Disable floating-point again - */ - isync(); - mtmsr(msr); + save_fpu_int(td); /* * Clear the current fp thread and pcb's CPU id @@ -187,3 +197,19 @@ save_fpu(struct thread *td) PCPU_SET(fputhread, NULL); } +/* + * Save fpu state without dropping ownership. This will only save state if + * the current fpu thread is `td'. + */ +void +save_fpu_nodrop(struct thread *td) +{ + struct thread *ftd; + + ftd = PCPU_GET(fputhread); + if (td != ftd) { + return; + } + + save_fpu_int(td); +} diff --git a/sys/powerpc/powerpc/ptrace_machdep.c b/sys/powerpc/powerpc/ptrace_machdep.c index bdfd902168eb..74cb0aedc01f 100644 --- a/sys/powerpc/powerpc/ptrace_machdep.c +++ b/sys/powerpc/powerpc/ptrace_machdep.c @@ -35,6 +35,7 @@ __FBSDID("$FreeBSD$"); #include #include #include +#include #include #include #include @@ -45,10 +46,14 @@ cpu_ptrace(struct thread *td, int req, void *addr, int data) int error; struct pcb *pcb; struct vec vec; + uint64_t vsr[32]; + uint64_t *vsr_dw1; + int vsr_idx; pcb = td->td_pcb; bzero(&vec, sizeof(vec)); + bzero(vsr, sizeof(vsr)); error = EINVAL; switch (req) { @@ -71,6 +76,43 @@ cpu_ptrace(struct thread *td, int req, void *addr, int data) memcpy(&pcb->pcb_vec, &vec, sizeof(vec)); } break; + case PT_GETVSRREGS: + if (!(cpu_features & PPC_FEATURE_HAS_VSX)) + break; + + if (pcb->pcb_flags & PCB_VSX) { + save_fpu_nodrop(td); + + /* + * Doubleword 0 of VSR0-VSR31 overlap with FPR0-FPR31 and + * VSR32-VSR63 overlap with VR0-VR31, so we only copy + * the non-overlapping data, which is doubleword 1 of VSR0-VSR31. + */ + for (vsr_idx = 0; vsr_idx < nitems(vsr); vsr_idx++) { + vsr_dw1 = (uint64_t *)&pcb->pcb_fpu.fpr[vsr_idx].vsr[2]; + vsr[vsr_idx] = *vsr_dw1; + } + } + error = copyout(&vsr, addr, sizeof(vsr)); + break; + case PT_SETVSRREGS: + if (!(cpu_features & PPC_FEATURE_HAS_VSX)) + break; + error = copyin(addr, &vsr, sizeof(vsr)); + if (error == 0) { + pcb->pcb_flags |= PCB_VSX; + + /* + * Doubleword 0 of VSR0-VSR31 overlap with FPR0-FPR31 and + * VSR32-VSR63 overlap with VR0-VR31, so we only copy + * the non-overlapping data, which is doubleword 1 of VSR0-VSR31. + */ + for (vsr_idx = 0; vsr_idx < nitems(vsr); vsr_idx++) { + vsr_dw1 = (uint64_t *)&pcb->pcb_fpu.fpr[vsr_idx].vsr[2]; + *vsr_dw1 = vsr[vsr_idx]; + } + } + break; default: break;