motorhead/qemu
1
0
Fork 0
mirror of https://github.com/Motorhead1991/qemu.git synced 2025-08-05 16:53:55 -06:00
Code Issues Projects Releases Packages Wiki Activity Actions

target/nios2: Clean up handling of tlbmisc in do_exception

Browse source 
The 4 lower bits, D, PERM, BAD, DBL, are unconditionally set on any
exception with EH=0, or so says Table 42 (Processor Status After
Taking Exception).

We currently do not set PERM or BAD at all, and only set/clear
DBL for tlb miss, and do not clear DBL for any other exception.

It is a bit confusing to set D in tlb_fill and the rest during
do_interrupt, so move the setting of D to do_interrupt as well.
To do this, split EXP_TLBD into two cases, EXCP_TLB_X and EXCP_TLB_D,
which allows us to distinguish them during do_interrupt.  Choose
a value for EXCP_TLB_D such that when truncated it produces the
correct value for exception.CAUSE.

Rename EXCP_TLB[RWX] to EXCP_PERM_[RWX], to emphasize that the
exception is permissions related.  Rename EXCP_SUPER[AD] to
EXCP_SUPERA_[DX] to emphasize that they are both "supervisor
address" exceptions, data and execute.

Retain the setting of tlbmisc.WE for the fast-tlb-miss path, as it
is being relied upon, but remove it from the permission path.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-37-richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2022-04-21 08:17:07 -07:00
parent 34cccb7462
commit be77e1d5fe
2 changed files with 73 additions and 37 deletions
Download patch file Download diff file Expand all files Collapse all files

13
target/nios2/cpu.h
View file

@ -166,13 +166,14 @@ FIELD(CR_TLBMISC, EE, 24, 1)
#define EXCP_UNALIGN 6
#define EXCP_UNALIGND 7
#define EXCP_DIV 8
#define EXCP_SUPERA 9
#define EXCP_SUPERA_X 9
#define EXCP_SUPERI 10
#define EXCP_SUPERD 11
#define EXCP_TLBD 12
#define EXCP_TLBX 13
#define EXCP_TLBR 14
#define EXCP_TLBW 15
#define EXCP_SUPERA_D 11
#define EXCP_TLB_X 12
#define EXCP_TLB_D (0x1000 | EXCP_TLB_X)
#define EXCP_PERM_X 13
#define EXCP_PERM_R 14
#define EXCP_PERM_W 15
#define EXCP_MPUI 16
#define EXCP_MPUD 17