[PATCH v2 1/4] LoongArch: Probe more CPU features from CPUCFG
From: Jiaxun Yang
Date: Thu Sep 12 2024 - 16:57:04 EST
Probe ISA level, TLB, IOCSR information from CPUCFG to
improve kernel resilience to different core implementations.
Signed-off-by: Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx>
---
arch/loongarch/include/asm/cpu.h | 4 +++
arch/loongarch/include/asm/loongarch.h | 3 +-
arch/loongarch/kernel/cpu-probe.c | 54 ++++++++++++++++++++++++----------
3 files changed, 44 insertions(+), 17 deletions(-)
diff --git a/arch/loongarch/include/asm/cpu.h b/arch/loongarch/include/asm/cpu.h
index 843f9c4ec980..251a15439cff 100644
--- a/arch/loongarch/include/asm/cpu.h
+++ b/arch/loongarch/include/asm/cpu.h
@@ -100,6 +100,8 @@ enum cpu_type_enum {
#define CPU_FEATURE_HYPERVISOR 25 /* CPU has hypervisor (running in VM) */
#define CPU_FEATURE_PTW 26 /* CPU has hardware page table walker */
#define CPU_FEATURE_AVECINT 27 /* CPU has avec interrupt */
+#define CPU_FEATURE_IOCSR 28 /* CPU has IOCSR */
+#define CPU_FEATURE_LSPW 29 /* CPU has LSPW */
#define LOONGARCH_CPU_CPUCFG BIT_ULL(CPU_FEATURE_CPUCFG)
#define LOONGARCH_CPU_LAM BIT_ULL(CPU_FEATURE_LAM)
@@ -129,5 +131,7 @@ enum cpu_type_enum {
#define LOONGARCH_CPU_HYPERVISOR BIT_ULL(CPU_FEATURE_HYPERVISOR)
#define LOONGARCH_CPU_PTW BIT_ULL(CPU_FEATURE_PTW)
#define LOONGARCH_CPU_AVECINT BIT_ULL(CPU_FEATURE_AVECINT)
+#define LOONGARCH_CPU_IOCSR BIT_ULL(CPU_FEATURE_IOCSR)
+#define LOONGARCH_CPU_LSPW BIT_ULL(CPU_FEATURE_LSPW)
#endif /* _ASM_CPU_H */
diff --git a/arch/loongarch/include/asm/loongarch.h b/arch/loongarch/include/asm/loongarch.h
index 631d249b3ef2..23af28f00c3c 100644
--- a/arch/loongarch/include/asm/loongarch.h
+++ b/arch/loongarch/include/asm/loongarch.h
@@ -60,8 +60,7 @@
#define CPUCFG0_PRID GENMASK(31, 0)
#define LOONGARCH_CPUCFG1 0x1
-#define CPUCFG1_ISGR32 BIT(0)
-#define CPUCFG1_ISGR64 BIT(1)
+#define CPUCFG1_ISA GENMASK(1, 0)
#define CPUCFG1_PAGING BIT(2)
#define CPUCFG1_IOCSR BIT(3)
#define CPUCFG1_PABITS GENMASK(11, 4)
diff --git a/arch/loongarch/kernel/cpu-probe.c b/arch/loongarch/kernel/cpu-probe.c
index 14f0449f5452..5dc8ca3c4387 100644
--- a/arch/loongarch/kernel/cpu-probe.c
+++ b/arch/loongarch/kernel/cpu-probe.c
@@ -92,11 +92,29 @@ static void cpu_probe_common(struct cpuinfo_loongarch *c)
unsigned long asid_mask;
c->options = LOONGARCH_CPU_CPUCFG | LOONGARCH_CPU_CSR |
- LOONGARCH_CPU_TLB | LOONGARCH_CPU_VINT | LOONGARCH_CPU_WATCH;
+ LOONGARCH_CPU_VINT | LOONGARCH_CPU_WATCH;
elf_hwcap = HWCAP_LOONGARCH_CPUCFG;
config = read_cpucfg(LOONGARCH_CPUCFG1);
+
+ switch (config & CPUCFG1_ISA) {
+ case 0:
+ set_isa(c, LOONGARCH_CPU_ISA_LA32R);
+ break;
+ case 1:
+ set_isa(c, LOONGARCH_CPU_ISA_LA32S);
+ break;
+ case 2:
+ set_isa(c, LOONGARCH_CPU_ISA_LA64);
+ break;
+ default:
+ pr_warn("Warning: unknown ISA level\n");
+ }
+ if (config & CPUCFG1_PAGING)
+ c->options |= LOONGARCH_CPU_TLB;
+ if (config & CPUCFG1_IOCSR)
+ c->options |= LOONGARCH_CPU_IOCSR;
if (config & CPUCFG1_UAL) {
c->options |= LOONGARCH_CPU_UAL;
elf_hwcap |= HWCAP_LOONGARCH_UAL;
@@ -157,6 +175,8 @@ static void cpu_probe_common(struct cpuinfo_loongarch *c)
elf_hwcap |= HWCAP_LOONGARCH_LBT_MIPS;
}
#endif
+ if (config & CPUCFG2_LSPW)
+ c->options |= LOONGARCH_CPU_LSPW;
config = read_cpucfg(LOONGARCH_CPUCFG6);
if (config & CPUCFG6_PMP)
@@ -222,6 +242,7 @@ static inline void cpu_probe_loongson(struct cpuinfo_loongarch *c, unsigned int
{
uint64_t *vendor = (void *)(&cpu_full_name[VENDOR_OFFSET]);
uint64_t *cpuname = (void *)(&cpu_full_name[CPUNAME_OFFSET]);
+ const char *core_name = "Unknown";
if (!__cpu_full_name[cpu])
__cpu_full_name[cpu] = cpu_full_name;
@@ -232,40 +253,43 @@ static inline void cpu_probe_loongson(struct cpuinfo_loongarch *c, unsigned int
switch (c->processor_id & PRID_SERIES_MASK) {
case PRID_SERIES_LA132:
c->cputype = CPU_LOONGSON32;
- set_isa(c, LOONGARCH_CPU_ISA_LA32S);
__cpu_family[cpu] = "Loongson-32bit";
- pr_info("32-bit Loongson Processor probed (LA132 Core)\n");
+ core_name = "LA132";
break;
case PRID_SERIES_LA264:
c->cputype = CPU_LOONGSON64;
- set_isa(c, LOONGARCH_CPU_ISA_LA64);
__cpu_family[cpu] = "Loongson-64bit";
- pr_info("64-bit Loongson Processor probed (LA264 Core)\n");
+ core_name = "LA264";
break;
case PRID_SERIES_LA364:
c->cputype = CPU_LOONGSON64;
- set_isa(c, LOONGARCH_CPU_ISA_LA64);
__cpu_family[cpu] = "Loongson-64bit";
- pr_info("64-bit Loongson Processor probed (LA364 Core)\n");
+ core_name = "LA364";
break;
case PRID_SERIES_LA464:
c->cputype = CPU_LOONGSON64;
- set_isa(c, LOONGARCH_CPU_ISA_LA64);
__cpu_family[cpu] = "Loongson-64bit";
- pr_info("64-bit Loongson Processor probed (LA464 Core)\n");
+ core_name = "LA464";
break;
case PRID_SERIES_LA664:
c->cputype = CPU_LOONGSON64;
- set_isa(c, LOONGARCH_CPU_ISA_LA64);
__cpu_family[cpu] = "Loongson-64bit";
- pr_info("64-bit Loongson Processor probed (LA664 Core)\n");
+ core_name = "LA664";
break;
default: /* Default to 64 bit */
- c->cputype = CPU_LOONGSON64;
- set_isa(c, LOONGARCH_CPU_ISA_LA64);
- __cpu_family[cpu] = "Loongson-64bit";
- pr_info("64-bit Loongson Processor probed (Unknown Core)\n");
+ if (c->isa_level & LOONGARCH_CPU_ISA_LA64) {
+ c->cputype = CPU_LOONGSON64;
+ __cpu_family[cpu] = "Loongson-64bit";
+ } else if (c->isa_level & LOONGARCH_CPU_ISA_LA32S) {
+ c->cputype = CPU_LOONGSON32;
+ __cpu_family[cpu] = "Loongson-32bit";
+ } else if (c->isa_level & LOONGARCH_CPU_ISA_LA32R) {
+ c->cputype = CPU_LOONGSON32;
+ __cpu_family[cpu] = "Loongson-32bit Reduced";
+ }
}
+
+ pr_info("%s Processor probed (%s Core)\n", __cpu_family[cpu], core_name);
}
#ifdef CONFIG_64BIT
--
2.46.0