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| author | Huacai Chen <chenhc@lemote.com> | 2017-03-16 13:00:26 (GMT) |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-04-12 10:41:14 (GMT) |
| commit | 3d5e13d891b0e7f4b7eee97aea1c15037a994d68 (patch) | |
| tree | 620a551bbbda6e9b6657fd516048a243072ca6ff /arch/mips/kernel/traps.c | |
| parent | c7f6633f7657a56bdb8628c129de6c3079eb7d07 (diff) | |
| download | linux-3d5e13d891b0e7f4b7eee97aea1c15037a994d68.tar.xz | |
MIPS: Check TLB before handle_ri_rdhwr() for Loongson-3
commit 5a34133167dce36666ea054e30a561b7f4413b7f upstream.
Loongson-3's micro TLB (ITLB) is not strictly a subset of JTLB. That
means: when a JTLB entry is replaced by hardware, there may be an old
valid entry exists in ITLB. So, a TLB miss exception may occur while
handle_ri_rdhwr() is running because it try to access EPC's content.
However, handle_ri_rdhwr() doesn't clear EXL, which makes a TLB Refill
exception be treated as a TLB Invalid exception and tlbp may fail. In
this case, if FTLB (which is usually set-associative instead of set-
associative) is enabled, a tlbp failure will cause an invalid tlbwi,
which will hang the whole system.
This patch rename handle_ri_rdhwr_vivt to handle_ri_rdhwr_tlbp and use
it for Loongson-3. It try to solve the same problem described as below,
but more straightforwards.
https://patchwork.linux-mips.org/patch/12591/
I think Loongson-2 has the same problem, but it has no FTLB, so we just
keep it as is.
Signed-off-by: Huacai Chen <chenhc@lemote.com>
Cc: Rui Wang <wangr@lemote.com>
Cc: John Crispin <john@phrozen.org>
Cc: Steven J . Hill <Steven.Hill@caviumnetworks.com>
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/15753/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/mips/kernel/traps.c')
| -rw-r--r-- | arch/mips/kernel/traps.c | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c index 3905003..ec87ef9 100644 --- a/arch/mips/kernel/traps.c +++ b/arch/mips/kernel/traps.c @@ -81,7 +81,7 @@ extern asmlinkage void handle_dbe(void); extern asmlinkage void handle_sys(void); extern asmlinkage void handle_bp(void); extern asmlinkage void handle_ri(void); -extern asmlinkage void handle_ri_rdhwr_vivt(void); +extern asmlinkage void handle_ri_rdhwr_tlbp(void); extern asmlinkage void handle_ri_rdhwr(void); extern asmlinkage void handle_cpu(void); extern asmlinkage void handle_ov(void); @@ -2352,9 +2352,18 @@ void __init trap_init(void) set_except_vector(EXCCODE_SYS, handle_sys); set_except_vector(EXCCODE_BP, handle_bp); - set_except_vector(EXCCODE_RI, rdhwr_noopt ? handle_ri : - (cpu_has_vtag_icache ? - handle_ri_rdhwr_vivt : handle_ri_rdhwr)); + + if (rdhwr_noopt) + set_except_vector(EXCCODE_RI, handle_ri); + else { + if (cpu_has_vtag_icache) + set_except_vector(EXCCODE_RI, handle_ri_rdhwr_tlbp); + else if (current_cpu_type() == CPU_LOONGSON3) + set_except_vector(EXCCODE_RI, handle_ri_rdhwr_tlbp); + else + set_except_vector(EXCCODE_RI, handle_ri_rdhwr); + } + set_except_vector(EXCCODE_CPU, handle_cpu); set_except_vector(EXCCODE_OV, handle_ov); set_except_vector(EXCCODE_TR, handle_tr); |