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-rw-r--r--arch/loongarch/kernel/cpu-probe.c299
1 files changed, 299 insertions, 0 deletions
diff --git a/arch/loongarch/kernel/cpu-probe.c b/arch/loongarch/kernel/cpu-probe.c
new file mode 100644
index 000000000..5adf0f736
--- /dev/null
+++ b/arch/loongarch/kernel/cpu-probe.c
@@ -0,0 +1,299 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Processor capabilities determination functions.
+ *
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/ptrace.h>
+#include <linux/smp.h>
+#include <linux/stddef.h>
+#include <linux/export.h>
+#include <linux/printk.h>
+#include <linux/uaccess.h>
+
+#include <asm/cpu-features.h>
+#include <asm/elf.h>
+#include <asm/fpu.h>
+#include <asm/loongarch.h>
+#include <asm/pgtable-bits.h>
+#include <asm/setup.h>
+
+/* Hardware capabilities */
+unsigned int elf_hwcap __read_mostly;
+EXPORT_SYMBOL_GPL(elf_hwcap);
+
+/*
+ * Determine the FCSR mask for FPU hardware.
+ */
+static inline void cpu_set_fpu_fcsr_mask(struct cpuinfo_loongarch *c)
+{
+ unsigned long sr, mask, fcsr, fcsr0, fcsr1;
+
+ fcsr = c->fpu_csr0;
+ mask = FPU_CSR_ALL_X | FPU_CSR_ALL_E | FPU_CSR_ALL_S | FPU_CSR_RM;
+
+ sr = read_csr_euen();
+ enable_fpu();
+
+ fcsr0 = fcsr & mask;
+ write_fcsr(LOONGARCH_FCSR0, fcsr0);
+ fcsr0 = read_fcsr(LOONGARCH_FCSR0);
+
+ fcsr1 = fcsr | ~mask;
+ write_fcsr(LOONGARCH_FCSR0, fcsr1);
+ fcsr1 = read_fcsr(LOONGARCH_FCSR0);
+
+ write_fcsr(LOONGARCH_FCSR0, fcsr);
+
+ write_csr_euen(sr);
+
+ c->fpu_mask = ~(fcsr0 ^ fcsr1) & ~mask;
+}
+
+static inline void set_elf_platform(int cpu, const char *plat)
+{
+ if (cpu == 0)
+ __elf_platform = plat;
+}
+
+/* MAP BASE */
+unsigned long vm_map_base;
+EXPORT_SYMBOL(vm_map_base);
+
+static void cpu_probe_addrbits(struct cpuinfo_loongarch *c)
+{
+#ifdef __NEED_ADDRBITS_PROBE
+ c->pabits = (read_cpucfg(LOONGARCH_CPUCFG1) & CPUCFG1_PABITS) >> 4;
+ c->vabits = (read_cpucfg(LOONGARCH_CPUCFG1) & CPUCFG1_VABITS) >> 12;
+ vm_map_base = 0UL - (1UL << c->vabits);
+#endif
+}
+
+static void set_isa(struct cpuinfo_loongarch *c, unsigned int isa)
+{
+ switch (isa) {
+ case LOONGARCH_CPU_ISA_LA64:
+ c->isa_level |= LOONGARCH_CPU_ISA_LA64;
+ fallthrough;
+ case LOONGARCH_CPU_ISA_LA32S:
+ c->isa_level |= LOONGARCH_CPU_ISA_LA32S;
+ fallthrough;
+ case LOONGARCH_CPU_ISA_LA32R:
+ c->isa_level |= LOONGARCH_CPU_ISA_LA32R;
+ break;
+ }
+}
+
+static void cpu_probe_common(struct cpuinfo_loongarch *c)
+{
+ unsigned int config;
+ unsigned long asid_mask;
+
+ c->options = LOONGARCH_CPU_CPUCFG | LOONGARCH_CPU_CSR |
+ LOONGARCH_CPU_TLB | LOONGARCH_CPU_VINT | LOONGARCH_CPU_WATCH;
+
+ elf_hwcap = HWCAP_LOONGARCH_CPUCFG;
+
+ config = read_cpucfg(LOONGARCH_CPUCFG1);
+ if (config & CPUCFG1_UAL) {
+ c->options |= LOONGARCH_CPU_UAL;
+ elf_hwcap |= HWCAP_LOONGARCH_UAL;
+ }
+ if (config & CPUCFG1_CRC32) {
+ c->options |= LOONGARCH_CPU_CRC32;
+ elf_hwcap |= HWCAP_LOONGARCH_CRC32;
+ }
+
+
+ config = read_cpucfg(LOONGARCH_CPUCFG2);
+ if (config & CPUCFG2_LAM) {
+ c->options |= LOONGARCH_CPU_LAM;
+ elf_hwcap |= HWCAP_LOONGARCH_LAM;
+ }
+ if (config & CPUCFG2_FP) {
+ c->options |= LOONGARCH_CPU_FPU;
+ elf_hwcap |= HWCAP_LOONGARCH_FPU;
+ }
+ if (config & CPUCFG2_COMPLEX) {
+ c->options |= LOONGARCH_CPU_COMPLEX;
+ elf_hwcap |= HWCAP_LOONGARCH_COMPLEX;
+ }
+ if (config & CPUCFG2_CRYPTO) {
+ c->options |= LOONGARCH_CPU_CRYPTO;
+ elf_hwcap |= HWCAP_LOONGARCH_CRYPTO;
+ }
+ if (config & CPUCFG2_LVZP) {
+ c->options |= LOONGARCH_CPU_LVZ;
+ elf_hwcap |= HWCAP_LOONGARCH_LVZ;
+ }
+
+ config = read_cpucfg(LOONGARCH_CPUCFG6);
+ if (config & CPUCFG6_PMP)
+ c->options |= LOONGARCH_CPU_PMP;
+
+ config = iocsr_read32(LOONGARCH_IOCSR_FEATURES);
+ if (config & IOCSRF_CSRIPI)
+ c->options |= LOONGARCH_CPU_CSRIPI;
+ if (config & IOCSRF_EXTIOI)
+ c->options |= LOONGARCH_CPU_EXTIOI;
+ if (config & IOCSRF_FREQSCALE)
+ c->options |= LOONGARCH_CPU_SCALEFREQ;
+ if (config & IOCSRF_FLATMODE)
+ c->options |= LOONGARCH_CPU_FLATMODE;
+ if (config & IOCSRF_EIODECODE)
+ c->options |= LOONGARCH_CPU_EIODECODE;
+ if (config & IOCSRF_VM)
+ c->options |= LOONGARCH_CPU_HYPERVISOR;
+
+ config = csr_read32(LOONGARCH_CSR_ASID);
+ config = (config & CSR_ASID_BIT) >> CSR_ASID_BIT_SHIFT;
+ asid_mask = GENMASK(config - 1, 0);
+ set_cpu_asid_mask(c, asid_mask);
+
+ config = read_csr_prcfg1();
+ c->ksave_mask = GENMASK((config & CSR_CONF1_KSNUM) - 1, 0);
+ c->ksave_mask &= ~(EXC_KSAVE_MASK | PERCPU_KSAVE_MASK | KVM_KSAVE_MASK);
+
+ config = read_csr_prcfg3();
+ switch (config & CSR_CONF3_TLBTYPE) {
+ case 0:
+ c->tlbsizemtlb = 0;
+ c->tlbsizestlbsets = 0;
+ c->tlbsizestlbways = 0;
+ c->tlbsize = 0;
+ break;
+ case 1:
+ c->tlbsizemtlb = ((config & CSR_CONF3_MTLBSIZE) >> CSR_CONF3_MTLBSIZE_SHIFT) + 1;
+ c->tlbsizestlbsets = 0;
+ c->tlbsizestlbways = 0;
+ c->tlbsize = c->tlbsizemtlb + c->tlbsizestlbsets * c->tlbsizestlbways;
+ break;
+ case 2:
+ c->tlbsizemtlb = ((config & CSR_CONF3_MTLBSIZE) >> CSR_CONF3_MTLBSIZE_SHIFT) + 1;
+ c->tlbsizestlbsets = 1 << ((config & CSR_CONF3_STLBIDX) >> CSR_CONF3_STLBIDX_SHIFT);
+ c->tlbsizestlbways = ((config & CSR_CONF3_STLBWAYS) >> CSR_CONF3_STLBWAYS_SHIFT) + 1;
+ c->tlbsize = c->tlbsizemtlb + c->tlbsizestlbsets * c->tlbsizestlbways;
+ break;
+ default:
+ pr_warn("Warning: unknown TLB type\n");
+ }
+}
+
+#define MAX_NAME_LEN 32
+#define VENDOR_OFFSET 0
+#define CPUNAME_OFFSET 9
+
+static char cpu_full_name[MAX_NAME_LEN] = " - ";
+
+static inline void cpu_probe_loongson(struct cpuinfo_loongarch *c, unsigned int cpu)
+{
+ uint64_t *vendor = (void *)(&cpu_full_name[VENDOR_OFFSET]);
+ uint64_t *cpuname = (void *)(&cpu_full_name[CPUNAME_OFFSET]);
+
+ if (!__cpu_full_name[cpu])
+ __cpu_full_name[cpu] = cpu_full_name;
+
+ *vendor = iocsr_read64(LOONGARCH_IOCSR_VENDOR);
+ *cpuname = iocsr_read64(LOONGARCH_IOCSR_CPUNAME);
+
+ 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");
+ 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");
+ 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");
+ 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");
+ 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");
+ 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");
+ }
+}
+
+#ifdef CONFIG_64BIT
+/* For use by uaccess.h */
+u64 __ua_limit;
+EXPORT_SYMBOL(__ua_limit);
+#endif
+
+const char *__cpu_family[NR_CPUS];
+const char *__cpu_full_name[NR_CPUS];
+const char *__elf_platform;
+
+static void cpu_report(void)
+{
+ struct cpuinfo_loongarch *c = &current_cpu_data;
+
+ pr_info("CPU%d revision is: %08x (%s)\n",
+ smp_processor_id(), c->processor_id, cpu_family_string());
+ if (c->options & LOONGARCH_CPU_FPU)
+ pr_info("FPU%d revision is: %08x\n", smp_processor_id(), c->fpu_vers);
+}
+
+void cpu_probe(void)
+{
+ unsigned int cpu = smp_processor_id();
+ struct cpuinfo_loongarch *c = &current_cpu_data;
+
+ /*
+ * Set a default ELF platform, cpu probe may later
+ * overwrite it with a more precise value
+ */
+ set_elf_platform(cpu, "loongarch");
+
+ c->cputype = CPU_UNKNOWN;
+ c->processor_id = read_cpucfg(LOONGARCH_CPUCFG0);
+ c->fpu_vers = (read_cpucfg(LOONGARCH_CPUCFG2) & CPUCFG2_FPVERS) >> 3;
+
+ c->fpu_csr0 = FPU_CSR_RN;
+ c->fpu_mask = FPU_CSR_RSVD;
+
+ cpu_probe_common(c);
+
+ per_cpu_trap_init(cpu);
+
+ switch (c->processor_id & PRID_COMP_MASK) {
+ case PRID_COMP_LOONGSON:
+ cpu_probe_loongson(c, cpu);
+ break;
+ }
+
+ BUG_ON(!__cpu_family[cpu]);
+ BUG_ON(c->cputype == CPU_UNKNOWN);
+
+ cpu_probe_addrbits(c);
+
+#ifdef CONFIG_64BIT
+ if (cpu == 0)
+ __ua_limit = ~((1ull << cpu_vabits) - 1);
+#endif
+
+ cpu_report();
+}