From 122394f1476b1c925a281b15399119500c8231c1 Mon Sep 17 00:00:00 2001 From: Alan Hayward Date: Thu, 31 May 2018 14:36:48 +0100 Subject: [PATCH] Function for reading the Aarch64 SVE vector length Returns 0 for systems without SVE support. Note the defines taken from Linux kernel headers in aarch64-sve-linux-ptrace.h. gdb/ * Makefile.in: Add new header. * gdb/arch/aarch64.h (sve_vg_from_vl): New macro. (sve_vl_from_vg): Likewise. (sve_vq_from_vl): Likewise. (sve_vl_from_vq): Likewise. (sve_vq_from_vg): Likewise. (sve_vg_from_vq): Likewise. * configure.nat: Add new c file. * nat/aarch64-sve-linux-ptrace.c: New file. * nat/aarch64-sve-linux-ptrace.h: New file. gdbserver/ * configure.srv: Add new c/h file. --- gdb/ChangeLog | 13 ++++++ gdb/Makefile.in | 1 + gdb/arch/aarch64.h | 17 +++++++ gdb/configure.nat | 3 +- gdb/gdbserver/ChangeLog | 4 ++ gdb/gdbserver/configure.srv | 1 + gdb/nat/aarch64-sve-linux-ptrace.c | 58 ++++++++++++++++++++++++ gdb/nat/aarch64-sve-linux-ptrace.h | 73 ++++++++++++++++++++++++++++++ 8 files changed, 169 insertions(+), 1 deletion(-) create mode 100644 gdb/nat/aarch64-sve-linux-ptrace.c create mode 100644 gdb/nat/aarch64-sve-linux-ptrace.h diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 2f4dae0664b..eaf0ce1fa7f 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,16 @@ +2018-05-31 Alan Hayward + + * Makefile.in: Add new header. + * gdb/arch/aarch64.h (sve_vg_from_vl): New macro. + (sve_vl_from_vg): Likewise. + (sve_vq_from_vl): Likewise. + (sve_vl_from_vq): Likewise. + (sve_vq_from_vg): Likewise. + (sve_vg_from_vq): Likewise. + * configure.nat: Add new c file. + * nat/aarch64-sve-linux-ptrace.c: New file. + * nat/aarch64-sve-linux-ptrace.h: New file. + 2018-05-31 Alan Hayward * aarch64-linux-nat.c (aarch64_linux_read_description): diff --git a/gdb/Makefile.in b/gdb/Makefile.in index 627944f9c41..a0e5b7edba6 100644 --- a/gdb/Makefile.in +++ b/gdb/Makefile.in @@ -1483,6 +1483,7 @@ HFILES_NO_SRCDIR = \ mi/mi-parse.h \ nat/aarch64-linux.h \ nat/aarch64-linux-hw-point.h \ + nat/aarch64-sve-linux-ptrace.h \ nat/amd64-linux-siginfo.h \ nat/gdb_ptrace.h \ nat/gdb_thread_db.h \ diff --git a/gdb/arch/aarch64.h b/gdb/arch/aarch64.h index b291a09770e..2f80a293bb9 100644 --- a/gdb/arch/aarch64.h +++ b/gdb/arch/aarch64.h @@ -52,6 +52,23 @@ enum aarch64_regnum #define AARCH64_V_REGS_NUM 32 #define AARCH64_NUM_REGS AARCH64_FPCR_REGNUM + 1 +/* There are a number of ways of expressing the current SVE vector size: + + VL : Vector Length. + The number of bytes in an SVE Z register. + VQ : Vector Quotient. + The number of 128bit chunks in an SVE Z register. + VG : Vector Gradient. + The number of 64bit chunks in an SVE Z register. */ + +#define sve_vg_from_vl(vl) ((vl) / 8) +#define sve_vl_from_vg(vg) ((vg) * 8) +#define sve_vq_from_vl(vl) ((vl) / 0x10) +#define sve_vl_from_vq(vq) ((vq) * 0x10) +#define sve_vq_from_vg(vg) (sve_vq_from_vl (sve_vl_from_vg (vg))) +#define sve_vg_from_vq(vq) (sve_vg_from_vl (sve_vl_from_vq (vq))) + + /* Maximum supported VQ value. Increase if required. */ #define AARCH64_MAX_SVE_VQ 16 diff --git a/gdb/configure.nat b/gdb/configure.nat index bcaeaf45833..7611266d86f 100644 --- a/gdb/configure.nat +++ b/gdb/configure.nat @@ -228,7 +228,8 @@ case ${gdb_host} in aarch64) # Host: AArch64 based machine running GNU/Linux NATDEPFILES="${NATDEPFILES} aarch64-linux-nat.o \ - aarch32-linux-nat.o aarch64-linux-hw-point.o aarch64-linux.o" + aarch32-linux-nat.o aarch64-linux-hw-point.o aarch64-linux.o \ + aarch64-sve-linux-ptrace.o" ;; arm) # Host: ARM based machine running GNU/Linux diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog index c61609bbd7c..ff385e44f62 100644 --- a/gdb/gdbserver/ChangeLog +++ b/gdb/gdbserver/ChangeLog @@ -1,3 +1,7 @@ +2018-05-31 Alan Hayward + + * configure.srv: Add new c/h file. + 2018-05-31 Alan Hayward * linux-aarch64-tdesc.c (aarch64_linux_read_description): Add diff --git a/gdb/gdbserver/configure.srv b/gdb/gdbserver/configure.srv index 7153ff339d7..72e6a0d87f4 100644 --- a/gdb/gdbserver/configure.srv +++ b/gdb/gdbserver/configure.srv @@ -54,6 +54,7 @@ case "${target}" in srv_tgtobj="$srv_tgtobj arch/aarch64-insn.o" srv_tgtobj="$srv_tgtobj arch/aarch64.o" srv_tgtobj="$srv_tgtobj linux-aarch64-tdesc.o" + srv_tgtobj="$srv_tgtobj aarch64-sve-linux-ptrace.o" srv_tgtobj="${srv_tgtobj} $srv_linux_obj" srv_linux_regsets=yes srv_linux_thread_db=yes diff --git a/gdb/nat/aarch64-sve-linux-ptrace.c b/gdb/nat/aarch64-sve-linux-ptrace.c new file mode 100644 index 00000000000..3a1dbae7099 --- /dev/null +++ b/gdb/nat/aarch64-sve-linux-ptrace.c @@ -0,0 +1,58 @@ +/* Common target dependent for AArch64 systems. + + Copyright (C) 2018 Free Software Foundation, Inc. + + This file is part of GDB. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program 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 General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . */ + +#include +#include +#include "common-defs.h" +#include "elf/external.h" +#include "elf/common.h" +#include "aarch64-sve-linux-ptrace.h" +#include "arch/aarch64.h" + +/* See nat/aarch64-sve-linux-ptrace.h. */ + +unsigned long +aarch64_sve_get_vq (int tid) +{ + struct iovec iovec; + struct user_sve_header header; + + iovec.iov_len = sizeof (header); + iovec.iov_base = &header; + + /* Ptrace gives the vector length in bytes. Convert it to VQ, the number of + 128bit chunks in a Z register. We use VQ because 128bits is the minimum + a Z register can increase in size. */ + + if (ptrace (PTRACE_GETREGSET, tid, NT_ARM_SVE, &iovec) < 0) + { + /* SVE is not supported. */ + return 0; + } + + long vq = sve_vq_from_vl (header.vl); + + if (!sve_vl_valid (header.vl)) + { + warning (_("Invalid SVE state from kernel; SVE disabled.")); + return 0; + } + + return vq; +} diff --git a/gdb/nat/aarch64-sve-linux-ptrace.h b/gdb/nat/aarch64-sve-linux-ptrace.h new file mode 100644 index 00000000000..a32ddf16768 --- /dev/null +++ b/gdb/nat/aarch64-sve-linux-ptrace.h @@ -0,0 +1,73 @@ +/* Common target dependent for AArch64 systems. + + Copyright (C) 2018 Free Software Foundation, Inc. + + This file is part of GDB. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program 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 General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . */ + +#ifndef AARCH64_SVE_LINUX_PTRACE_H +#define AARCH64_SVE_LINUX_PTRACE_H + +/* Where indicated, this file contains defines and macros lifted directly from + the Linux kernel headers, with no modification. + Refer to Linux kernel documentation for details. */ + +#include +#include +#include +#include + +/* Read VQ for the given tid using ptrace. If SVE is not supported then zero + is returned (on a system that supports SVE, then VQ cannot be zero). */ + +extern unsigned long aarch64_sve_get_vq (int tid); + +/* Structures and defines taken from sigcontext.h. */ + +#ifndef SVE_SIG_ZREGS_SIZE + +#define SVE_VQ_BYTES 16 /* number of bytes per quadword */ + +#define SVE_VQ_MIN 1 +#define SVE_VQ_MAX 512 + +#define SVE_VL_MIN (SVE_VQ_MIN * SVE_VQ_BYTES) +#define SVE_VL_MAX (SVE_VQ_MAX * SVE_VQ_BYTES) + +#define SVE_NUM_ZREGS 32 +#define SVE_NUM_PREGS 16 + +#define sve_vl_valid(vl) \ + ((vl) % SVE_VQ_BYTES == 0 && (vl) >= SVE_VL_MIN && (vl) <= SVE_VL_MAX) + +#endif /* SVE_SIG_ZREGS_SIZE. */ + + +/* Structures and defines taken from ptrace.h. */ + +#ifndef SVE_PT_SVE_ZREG_SIZE + +struct user_sve_header { + __u32 size; /* total meaningful regset content in bytes */ + __u32 max_size; /* maxmium possible size for this thread */ + __u16 vl; /* current vector length */ + __u16 max_vl; /* maximum possible vector length */ + __u16 flags; + __u16 __reserved; +}; + +#endif /* SVE_PT_SVE_ZREG_SIZE. */ + +#endif /* aarch64-sve-linux-ptrace.h */ -- 2.30.2