Commit 7db5e9e9e5e6c10d7d ("MIPS: loongson64: fix FTLB configuration") move decode_configs() from the beginning of cpu_probe_loongson() to the end in order to fix FTLB configuration. However, it breaks the CPUCFG decoding because decode_configs() use "c->options = xxxx" rather than "c->options |= xxxx", all information get from CPUCFG by decode_cpucfg() is lost.
This causes error when creating a KVM guest on Loongson-3A4000: Exception Code: 4 not handled @ PC: 0000000087ad5981, inst: 0xcb7a1898 BadVaddr: 0x0 Status: 0x0
Fix this by moving the c->cputype setting to the beginning and moving decode_configs() after that.
Fixes: 7db5e9e9e5e6c10d7d ("MIPS: loongson64: fix FTLB configuration") Cc: stable@vger.kernel.org Cc: Huang Pei huangpei@loongson.cn Signed-off-by: Huacai Chen chenhuacai@loongson.cn --- arch/mips/kernel/cpu-probe.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-)
diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c index e79adcb128e6..b406d8bfb15a 100644 --- a/arch/mips/kernel/cpu-probe.c +++ b/arch/mips/kernel/cpu-probe.c @@ -1677,7 +1677,10 @@ static inline void decode_cpucfg(struct cpuinfo_mips *c)
static inline void cpu_probe_loongson(struct cpuinfo_mips *c, unsigned int cpu) { + c->cputype = CPU_LOONGSON64; + /* All Loongson processors covered here define ExcCode 16 as GSExc. */ + decode_configs(c); c->options |= MIPS_CPU_GSEXCEX;
switch (c->processor_id & PRID_IMP_MASK) { @@ -1687,7 +1690,6 @@ static inline void cpu_probe_loongson(struct cpuinfo_mips *c, unsigned int cpu) case PRID_REV_LOONGSON2K_R1_1: case PRID_REV_LOONGSON2K_R1_2: case PRID_REV_LOONGSON2K_R1_3: - c->cputype = CPU_LOONGSON64; __cpu_name[cpu] = "Loongson-2K"; set_elf_platform(cpu, "gs264e"); set_isa(c, MIPS_CPU_ISA_M64R2); @@ -1700,14 +1702,12 @@ static inline void cpu_probe_loongson(struct cpuinfo_mips *c, unsigned int cpu) switch (c->processor_id & PRID_REV_MASK) { case PRID_REV_LOONGSON3A_R2_0: case PRID_REV_LOONGSON3A_R2_1: - c->cputype = CPU_LOONGSON64; __cpu_name[cpu] = "ICT Loongson-3"; set_elf_platform(cpu, "loongson3a"); set_isa(c, MIPS_CPU_ISA_M64R2); break; case PRID_REV_LOONGSON3A_R3_0: case PRID_REV_LOONGSON3A_R3_1: - c->cputype = CPU_LOONGSON64; __cpu_name[cpu] = "ICT Loongson-3"; set_elf_platform(cpu, "loongson3a"); set_isa(c, MIPS_CPU_ISA_M64R2); @@ -1727,7 +1727,6 @@ static inline void cpu_probe_loongson(struct cpuinfo_mips *c, unsigned int cpu) c->ases &= ~MIPS_ASE_VZ; /* VZ of Loongson-3A2000/3000 is incomplete */ break; case PRID_IMP_LOONGSON_64G: - c->cputype = CPU_LOONGSON64; __cpu_name[cpu] = "ICT Loongson-3"; set_elf_platform(cpu, "loongson3a"); set_isa(c, MIPS_CPU_ISA_M64R2); @@ -1737,8 +1736,6 @@ static inline void cpu_probe_loongson(struct cpuinfo_mips *c, unsigned int cpu) panic("Unknown Loongson Processor ID!"); break; } - - decode_configs(c); } #else static inline void cpu_probe_loongson(struct cpuinfo_mips *c, unsigned int cpu) { }
On Mon, Jun 26, 2023 at 03:50:14PM +0800, Huacai Chen wrote:
Commit 7db5e9e9e5e6c10d7d ("MIPS: loongson64: fix FTLB configuration") move decode_configs() from the beginning of cpu_probe_loongson() to the end in order to fix FTLB configuration. However, it breaks the CPUCFG decoding because decode_configs() use "c->options = xxxx" rather than "c->options |= xxxx", all information get from CPUCFG by decode_cpucfg() is lost.
This causes error when creating a KVM guest on Loongson-3A4000: Exception Code: 4 not handled @ PC: 0000000087ad5981, inst: 0xcb7a1898 BadVaddr: 0x0 Status: 0x0
Fix this by moving the c->cputype setting to the beginning and moving decode_configs() after that.
Fixes: 7db5e9e9e5e6c10d7d ("MIPS: loongson64: fix FTLB configuration") Cc: stable@vger.kernel.org Cc: Huang Pei huangpei@loongson.cn Signed-off-by: Huacai Chen chenhuacai@loongson.cn
arch/mips/kernel/cpu-probe.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-)
applied to mips-next.
Thomas.
On Mon, 26 Jun 2023, Huacai Chen wrote:
diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c index e79adcb128e6..b406d8bfb15a 100644 --- a/arch/mips/kernel/cpu-probe.c +++ b/arch/mips/kernel/cpu-probe.c @@ -1677,7 +1677,10 @@ static inline void decode_cpucfg(struct cpuinfo_mips *c) static inline void cpu_probe_loongson(struct cpuinfo_mips *c, unsigned int cpu) {
- c->cputype = CPU_LOONGSON64;
- /* All Loongson processors covered here define ExcCode 16 as GSExc. */
- decode_configs(c); c->options |= MIPS_CPU_GSEXCEX;
This has misplaced the comment, which is not about `decode_configs' at all. For consistency with other code it also seems like `decode_configs' would best be called as the first statement of `cpu_probe_loongson'.
Maciej
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