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Diffstat (limited to 'target/arm/tcg/m-nocp.decode')
| -rw-r--r-- | target/arm/tcg/m-nocp.decode | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/target/arm/tcg/m-nocp.decode b/target/arm/tcg/m-nocp.decode new file mode 100644 index 0000000000..b65c801c97 --- /dev/null +++ b/target/arm/tcg/m-nocp.decode @@ -0,0 +1,72 @@ +# M-profile UserFault.NOCP exception handling +# +# Copyright (c) 2020 Linaro, Ltd +# +# This library is free software; you can redistribute it and/or +# modify it under the terms of the GNU Lesser General Public +# License as published by the Free Software Foundation; either +# version 2.1 of the License, or (at your option) any later version. +# +# This library 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 +# Lesser General Public License for more details. +# +# You should have received a copy of the GNU Lesser General Public +# License along with this library; if not, see <http://www.gnu.org/licenses/>. + +# +# This file is processed by scripts/decodetree.py +# +# For M-profile, the architecture specifies that NOCP UsageFaults +# should take precedence over UNDEF faults over the whole wide +# range of coprocessor-space encodings, with the exception of +# VLLDM and VLSTM. (Compare v8.1M IsCPInstruction() pseudocode and +# v8M Arm ARM rule R_QLGM.) This isn't mandatory for v8.0M but we choose +# to behave the same as v8.1M. +# This decode is handled before any others (and in particular before +# decoding FP instructions which are in the coprocessor space). +# If the coprocessor is not present or disabled then we will generate +# the NOCP exception; otherwise we let the insn through to the main decode. + +%vd_dp 22:1 12:4 +%vd_sp 12:4 22:1 + +&nocp cp + +# M-profile VLDR/VSTR to sysreg +%vldr_sysreg 22:1 13:3 +%imm7_0x4 0:7 !function=times_4 + +&vldr_sysreg rn reg imm a w p +@vldr_sysreg .... ... . a:1 . . . rn:4 ... . ... .. ....... \ + reg=%vldr_sysreg imm=%imm7_0x4 &vldr_sysreg + +{ + # Special cases which do not take an early NOCP: VLLDM and VLSTM + VLLDM_VLSTM 1110 1100 001 l:1 rn:4 0000 1010 op:1 000 0000 + # VSCCLRM (new in v8.1M) is similar: + VSCCLRM 1110 1100 1.01 1111 .... 1011 imm:7 0 vd=%vd_dp size=3 + VSCCLRM 1110 1100 1.01 1111 .... 1010 imm:8 vd=%vd_sp size=2 + + # FP system register accesses: these are a special case because accesses + # to FPCXT_NS succeed even if the FPU is disabled. We therefore need + # to handle them before the big NOCP blocks. Note that within these + # insns NOCP still has higher priority than UNDEFs; this is implemented + # by their returning 'false' for UNDEF so as to fall through into the + # NOCP check (in contrast to VLLDM etc, which call unallocated_encoding() + # for the UNDEFs there that must take precedence over NOCP.) + + VMSR_VMRS ---- 1110 111 l:1 reg:4 rt:4 1010 0001 0000 + + # P=0 W=0 is SEE "Related encodings", so split into two patterns + VLDR_sysreg ---- 110 1 . . w:1 1 .... ... 0 111 11 ....... @vldr_sysreg p=1 + VLDR_sysreg ---- 110 0 . . 1 1 .... ... 0 111 11 ....... @vldr_sysreg p=0 w=1 + VSTR_sysreg ---- 110 1 . . w:1 0 .... ... 0 111 11 ....... @vldr_sysreg p=1 + VSTR_sysreg ---- 110 0 . . 1 0 .... ... 0 111 11 ....... @vldr_sysreg p=0 w=1 + + NOCP 111- 1110 ---- ---- ---- cp:4 ---- ---- &nocp + NOCP 111- 110- ---- ---- ---- cp:4 ---- ---- &nocp + # From v8.1M onwards this range will also NOCP: + NOCP_8_1 111- 1111 ---- ---- ---- ---- ---- ---- &nocp cp=10 +} |