[PATCH v2 1/4] LoongArch: Probe more CPU features from CPUCFG

Jiaxun Yang posted 4 patches 2 months, 2 weeks ago
There is a newer version of this series
[PATCH v2 1/4] LoongArch: Probe more CPU features from CPUCFG
Posted by Jiaxun Yang 2 months, 2 weeks ago
Probe ISA level, TLB, IOCSR information from CPUCFG to
improve kernel resilience to different core implementations.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
---
 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
Re: [PATCH v2 1/4] LoongArch: Probe more CPU features from CPUCFG
Posted by Huacai Chen 2 months, 2 weeks ago
Hi, Jiaxun,

On Fri, Sep 13, 2024 at 4:56 AM Jiaxun Yang <jiaxun.yang@flygoat.com> wrote:
>
> Probe ISA level, TLB, IOCSR information from CPUCFG to
> improve kernel resilience to different core implementations.
>
> Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
> ---
>  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 */
I don't see LSPW being used, so just remove it now?

>
>  #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";
> +               }
I prefer to move this part before the switch-case of PRID (and it is
better to convert to a switch-case too), then the switch-case of PRID
can be only used for probing core-name.

Huacai

>         }
> +
> +       pr_info("%s Processor probed (%s Core)\n", __cpu_family[cpu], core_name);
>  }
>
>  #ifdef CONFIG_64BIT
>
> --
> 2.46.0
>