1# M-profile UserFault.NOCP exception handling 2# 3# Copyright (c) 2020 Linaro, Ltd 4# 5# This library is free software; you can redistribute it and/or 6# modify it under the terms of the GNU Lesser General Public 7# License as published by the Free Software Foundation; either 8# version 2.1 of the License, or (at your option) any later version. 9# 10# This library is distributed in the hope that it will be useful, 11# but WITHOUT ANY WARRANTY; without even the implied warranty of 12# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13# Lesser General Public License for more details. 14# 15# You should have received a copy of the GNU Lesser General Public 16# License along with this library; if not, see <http://www.gnu.org/licenses/>. 17 18# 19# This file is processed by scripts/decodetree.py 20# 21# For M-profile, the architecture specifies that NOCP UsageFaults 22# should take precedence over UNDEF faults over the whole wide 23# range of coprocessor-space encodings, with the exception of 24# VLLDM and VLSTM. (Compare v8.1M IsCPInstruction() pseudocode and 25# v8M Arm ARM rule R_QLGM.) This isn't mandatory for v8.0M but we choose 26# to behave the same as v8.1M. 27# This decode is handled before any others (and in particular before 28# decoding FP instructions which are in the coprocessor space). 29# If the coprocessor is not present or disabled then we will generate 30# the NOCP exception; otherwise we let the insn through to the main decode. 31 32%vd_dp 22:1 12:4 33%vd_sp 12:4 22:1 34 35&nocp cp 36 37# M-profile VLDR/VSTR to sysreg 38%vldr_sysreg 22:1 13:3 39%imm7_0x4 0:7 !function=times_4 40 41&vldr_sysreg rn reg imm a w p 42@vldr_sysreg .... ... . a:1 . . . rn:4 ... . ... .. ....... \ 43 reg=%vldr_sysreg imm=%imm7_0x4 &vldr_sysreg 44 45{ 46 # Special cases which do not take an early NOCP: VLLDM and VLSTM 47 VLLDM_VLSTM 1110 1100 001 l:1 rn:4 0000 1010 op:1 000 0000 48 # VSCCLRM (new in v8.1M) is similar: 49 VSCCLRM 1110 1100 1.01 1111 .... 1011 imm:7 0 vd=%vd_dp size=3 50 VSCCLRM 1110 1100 1.01 1111 .... 1010 imm:8 vd=%vd_sp size=2 51 52 # FP system register accesses: these are a special case because accesses 53 # to FPCXT_NS succeed even if the FPU is disabled. We therefore need 54 # to handle them before the big NOCP blocks. Note that within these 55 # insns NOCP still has higher priority than UNDEFs; this is implemented 56 # by their returning 'false' for UNDEF so as to fall through into the 57 # NOCP check (in contrast to VLLDM etc, which call unallocated_encoding() 58 # for the UNDEFs there that must take precedence over NOCP.) 59 60 VMSR_VMRS ---- 1110 111 l:1 reg:4 rt:4 1010 0001 0000 61 62 # P=0 W=0 is SEE "Related encodings", so split into two patterns 63 VLDR_sysreg ---- 110 1 . . w:1 1 .... ... 0 111 11 ....... @vldr_sysreg p=1 64 VLDR_sysreg ---- 110 0 . . 1 1 .... ... 0 111 11 ....... @vldr_sysreg p=0 w=1 65 VSTR_sysreg ---- 110 1 . . w:1 0 .... ... 0 111 11 ....... @vldr_sysreg p=1 66 VSTR_sysreg ---- 110 0 . . 1 0 .... ... 0 111 11 ....... @vldr_sysreg p=0 w=1 67 68 NOCP 111- 1110 ---- ---- ---- cp:4 ---- ---- &nocp 69 NOCP 111- 110- ---- ---- ---- cp:4 ---- ---- &nocp 70 # From v8.1M onwards this range will also NOCP: 71 NOCP_8_1 111- 1111 ---- ---- ---- ---- ---- ---- &nocp cp=10 72} 73