diff options
| -rw-r--r-- | arch/mips/Kconfig | 12 | ||||
| -rw-r--r-- | arch/mips/include/asm/cpu-info.h | 9 | ||||
| -rw-r--r-- | arch/mips/include/asm/mach-loongson64/cpucfg-emul.h | 63 | ||||
| -rw-r--r-- | arch/mips/kernel/cpu-probe.c | 9 | ||||
| -rw-r--r-- | arch/mips/kernel/traps.c | 45 | ||||
| -rw-r--r-- | arch/mips/loongson64/Makefile | 1 | ||||
| -rw-r--r-- | arch/mips/loongson64/cpucfg-emul.c | 217 |
7 files changed, 356 insertions, 0 deletions
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index f347312ecd74..c5fe30c78402 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -1441,6 +1441,18 @@ config CPU_LOONGSON3_WORKAROUNDS If unsure, please say Y. +config CPU_LOONGSON3_CPUCFG_EMULATION + bool "Emulate the CPUCFG instruction on older Loongson cores" + default y + depends on CPU_LOONGSON64 + help + Loongson-3A R4 and newer have the CPUCFG instruction available for + userland to query CPU capabilities, much like CPUID on x86. This + option provides emulation of the instruction on older Loongson + cores, back to Loongson-3A1000. + + If unsure, please say Y. + config CPU_LOONGSON2E bool "Loongson 2E" depends on SYS_HAS_CPU_LOONGSON2E diff --git a/arch/mips/include/asm/cpu-info.h b/arch/mips/include/asm/cpu-info.h index bce3ea7fff7c..a600670d00e9 100644 --- a/arch/mips/include/asm/cpu-info.h +++ b/arch/mips/include/asm/cpu-info.h @@ -105,6 +105,15 @@ struct cpuinfo_mips { unsigned int gtoffset_mask; unsigned int guestid_mask; unsigned int guestid_cache; + +#ifdef CONFIG_CPU_LOONGSON3_CPUCFG_EMULATION + /* CPUCFG data for this CPU, synthesized at probe time. + * + * CPUCFG select 0 is PRId, 4 and above are unimplemented for now. + * So the only stored values are for CPUCFG selects 1-3 inclusive. + */ + u32 loongson3_cpucfg_data[3]; +#endif } __attribute__((aligned(SMP_CACHE_BYTES))); extern struct cpuinfo_mips cpu_data[]; diff --git a/arch/mips/include/asm/mach-loongson64/cpucfg-emul.h b/arch/mips/include/asm/mach-loongson64/cpucfg-emul.h new file mode 100644 index 000000000000..01dc308df7b2 --- /dev/null +++ b/arch/mips/include/asm/mach-loongson64/cpucfg-emul.h @@ -0,0 +1,63 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_MACH_LOONGSON64_CPUCFG_EMUL_H_ +#define _ASM_MACH_LOONGSON64_CPUCFG_EMUL_H_ + +#include <asm/cpu-info.h> + +#ifdef CONFIG_CPU_LOONGSON3_CPUCFG_EMULATION + +#include <loongson_regs.h> + +#define LOONGSON_FPREV_MASK 0x7 + +void loongson3_cpucfg_synthesize_data(struct cpuinfo_mips *c); + +static inline u32 loongson3_cpucfg_read_synthesized(struct cpuinfo_mips *c, + __u64 sel) +{ + switch (sel) { + case LOONGSON_CFG0: + return c->processor_id; + case LOONGSON_CFG1: + case LOONGSON_CFG2: + case LOONGSON_CFG3: + return c->loongson3_cpucfg_data[sel - 1]; + case LOONGSON_CFG4: + case LOONGSON_CFG5: + /* CPUCFG selects 4 and 5 are related to the input clock + * signal. + * + * Unimplemented for now. + */ + return 0; + case LOONGSON_CFG6: + /* CPUCFG select 6 is for the undocumented Safe Extension. */ + return 0; + case LOONGSON_CFG7: + /* CPUCFG select 7 is for the virtualization extension. + * We don't know if the two currently known features are + * supported on older cores according to the public + * documentation, so leave this at zero. + */ + return 0; + } + + /* + * Return 0 for unrecognized CPUCFG selects, which is real hardware + * behavior observed on Loongson 3A R4. + */ + return 0; +} +#else +static inline void loongson3_cpucfg_synthesize_data(struct cpuinfo_mips *c) +{ +} + +static inline u32 loongson3_cpucfg_read_synthesized(struct cpuinfo_mips *c, + __u64 sel) +{ + return 0; +} +#endif + +#endif /* _ASM_MACH_LOONGSON64_CPUCFG_EMUL_H_ */ diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c index f7c4b1d86274..6b93162d7c5a 100644 --- a/arch/mips/kernel/cpu-probe.c +++ b/arch/mips/kernel/cpu-probe.c @@ -28,6 +28,8 @@ #include <asm/spram.h> #include <linux/uaccess.h> +#include <asm/mach-loongson64/cpucfg-emul.h> + /* Hardware capabilities */ unsigned int elf_hwcap __read_mostly; EXPORT_SYMBOL_GPL(elf_hwcap); @@ -2400,6 +2402,13 @@ void cpu_probe(void) cpu_probe_vmbits(c); + /* Synthesize CPUCFG data if running on Loongson processors; + * no-op otherwise. + * + * This looks at previously probed features, so keep this at bottom. + */ + loongson3_cpucfg_synthesize_data(c); + #ifdef CONFIG_64BIT if (cpu == 0) __ua_limit = ~((1ull << cpu_vmbits) - 1); diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c index 89eb82f6c837..2d5b16daf331 100644 --- a/arch/mips/kernel/traps.c +++ b/arch/mips/kernel/traps.c @@ -71,6 +71,8 @@ #include <asm/tlbex.h> #include <asm/uasm.h> +#include <asm/mach-loongson64/cpucfg-emul.h> + extern void check_wait(void); extern asmlinkage void rollback_handle_int(void); extern asmlinkage void handle_int(void); @@ -693,6 +695,44 @@ static int simulate_sync(struct pt_regs *regs, unsigned int opcode) return -1; /* Must be something else ... */ } +/* + * Loongson-3 CSR instructions emulation + */ + +#ifdef CONFIG_CPU_LOONGSON3_CPUCFG_EMULATION + +#define LWC2 0xc8000000 +#define RS BASE +#define CSR_OPCODE2 0x00000118 +#define CSR_OPCODE2_MASK 0x000007ff +#define CSR_FUNC_MASK RT +#define CSR_FUNC_CPUCFG 0x8 + +static int simulate_loongson3_cpucfg(struct pt_regs *regs, + unsigned int opcode) +{ + int op = opcode & OPCODE; + int op2 = opcode & CSR_OPCODE2_MASK; + int csr_func = (opcode & CSR_FUNC_MASK) >> 16; + + if (op == LWC2 && op2 == CSR_OPCODE2 && csr_func == CSR_FUNC_CPUCFG) { + int rd = (opcode & RD) >> 11; + int rs = (opcode & RS) >> 21; + __u64 sel = regs->regs[rs]; + + perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 0); + + regs->regs[rd] = loongson3_cpucfg_read_synthesized( + ¤t_cpu_data, sel); + + return 0; + } + + /* Not ours. */ + return -1; +} +#endif /* CONFIG_CPU_LOONGSON3_CPUCFG_EMULATION */ + asmlinkage void do_ov(struct pt_regs *regs) { enum ctx_state prev_state; @@ -1166,6 +1206,11 @@ no_r2_instr: if (status < 0) status = simulate_fp(regs, opcode, old_epc, old31); + +#ifdef CONFIG_CPU_LOONGSON3_CPUCFG_EMULATION + if (status < 0) + status = simulate_loongson3_cpucfg(regs, opcode); +#endif } else if (cpu_has_mmips) { unsigned short mmop[2] = { 0 }; diff --git a/arch/mips/loongson64/Makefile b/arch/mips/loongson64/Makefile index 6f3c2b47f66f..61f6add20530 100644 --- a/arch/mips/loongson64/Makefile +++ b/arch/mips/loongson64/Makefile @@ -10,3 +10,4 @@ obj-$(CONFIG_NUMA) += numa.o obj-$(CONFIG_RS780_HPET) += hpet.o obj-$(CONFIG_PCI) += pci.o obj-$(CONFIG_SUSPEND) += pm.o +obj-$(CONFIG_CPU_LOONGSON3_CPUCFG_EMULATION) += cpucfg-emul.o diff --git a/arch/mips/loongson64/cpucfg-emul.c b/arch/mips/loongson64/cpucfg-emul.c new file mode 100644 index 000000000000..fdd52b21c1df --- /dev/null +++ b/arch/mips/loongson64/cpucfg-emul.c @@ -0,0 +1,217 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/smp.h> +#include <linux/types.h> +#include <asm/cpu.h> +#include <asm/cpu-info.h> + +#include <loongson_regs.h> +#include <cpucfg-emul.h> + +static bool is_loongson(struct cpuinfo_mips *c) +{ + switch (c->processor_id & PRID_COMP_MASK) { + case PRID_COMP_LEGACY: + return ((c->processor_id & PRID_IMP_MASK) == + PRID_IMP_LOONGSON_64C); + + case PRID_COMP_LOONGSON: + return true; + + default: + return false; + } +} + +static u32 get_loongson_fprev(struct cpuinfo_mips *c) +{ + return c->fpu_id & LOONGSON_FPREV_MASK; +} + +static bool cpu_has_uca(void) +{ + u32 diag = read_c0_diag(); + u32 new_diag; + + if (diag & LOONGSON_DIAG_UCAC) + /* UCA is already enabled. */ + return true; + + /* See if UCAC bit can be flipped on. This should be safe. */ + new_diag = diag | LOONGSON_DIAG_UCAC; + write_c0_diag(new_diag); + new_diag = read_c0_diag(); + write_c0_diag(diag); + + return (new_diag & LOONGSON_DIAG_UCAC) != 0; +} + +static void probe_uca(struct cpuinfo_mips *c) +{ + if (cpu_has_uca()) + c->loongson3_cpucfg_data[0] |= LOONGSON_CFG1_LSUCA; +} + +static void decode_loongson_config6(struct cpuinfo_mips *c) +{ + u32 config6 = read_c0_config6(); + + if (config6 & MIPS_CONF6_LOONGSON_SFBEN) + c->loongson3_cpucfg_data[0] |= LOONGSON_CFG1_SFBP; + if (config6 & MIPS_CONF6_LOONGSON_LLEXC) + c->loongson3_cpucfg_data[0] |= LOONGSON_CFG1_LLEXC; + if (config6 & MIPS_CONF6_LOONGSON_SCRAND) + c->loongson3_cpucfg_data[0] |= LOONGSON_CFG1_SCRAND; +} + +static void patch_cpucfg_sel1(struct cpuinfo_mips *c) +{ + u64 ases = c->ases; + u64 options = c->options; + u32 data = c->loongson3_cpucfg_data[0]; + + if (options & MIPS_CPU_FPU) { + data |= LOONGSON_CFG1_FP; + data |= get_loongson_fprev(c) << LOONGSON_CFG1_FPREV_OFFSET; + } + if (ases & MIPS_ASE_LOONGSON_MMI) + data |= LOONGSON_CFG1_MMI; + if (ases & MIPS_ASE_MSA) + data |= LOONGSON_CFG1_MSA1; + + c->loongson3_cpucfg_data[0] = data; +} + +static void patch_cpucfg_sel2(struct cpuinfo_mips *c) +{ + u64 ases = c->ases; + u64 options = c->options; + u32 data = c->loongson3_cpucfg_data[1]; + + if (ases & MIPS_ASE_LOONGSON_EXT) + data |= LOONGSON_CFG2_LEXT1; + if (ases & MIPS_ASE_LOONGSON_EXT2) + data |= LOONGSON_CFG2_LEXT2; + if (options & MIPS_CPU_LDPTE) + data |= LOONGSON_CFG2_LSPW; + + if (ases & MIPS_ASE_VZ) + data |= LOONGSON_CFG2_LVZP; + else + data &= ~LOONGSON_CFG2_LVZREV; + + c->loongson3_cpucfg_data[1] = data; +} + +static void patch_cpucfg_sel3(struct cpuinfo_mips *c) +{ + u64 ases = c->ases; + u32 data = c->loongson3_cpucfg_data[2]; + + if (ases & MIPS_ASE_LOONGSON_CAM) { + data |= LOONGSON_CFG3_LCAMP; + } else { + data &= ~LOONGSON_CFG3_LCAMREV; + data &= ~LOONGSON_CFG3_LCAMNUM; + data &= ~LOONGSON_CFG3_LCAMKW; + data &= ~LOONGSON_CFG3_LCAMVW; + } + + c->loongson3_cpucfg_data[2] = data; +} + +void loongson3_cpucfg_synthesize_data(struct cpuinfo_mips *c) +{ + /* Only engage the logic on Loongson processors. */ + if (!is_loongson(c)) + return; + + /* CPUs with CPUCFG support don't need to synthesize anything. */ + if (cpu_has_cfg()) + return; + + c->loongson3_cpucfg_data[0] = 0; + c->loongson3_cpucfg_data[1] = 0; + c->loongson3_cpucfg_data[2] = 0; + + /* Add CPUCFG features non-discoverable otherwise. + * + * All Loongson processors covered by CPUCFG emulation have distinct + * PRID_REV, so take advantage of this. + */ + switch (c->processor_id & PRID_REV_MASK) { + case PRID_REV_LOONGSON3A_R1: + c->loongson3_cpucfg_data[0] |= (LOONGSON_CFG1_LSLDR0 | + LOONGSON_CFG1_LSSYNCI | LOONGSON_CFG1_LSUCA | + LOONGSON_CFG1_LLSYNC | LOONGSON_CFG1_TGTSYNC); + c->loongson3_cpucfg_data[1] |= (LOONGSON_CFG2_LBT1 | + LOONGSON_CFG2_LPMP | LOONGSON_CFG2_LPM_REV1); + c->loongson3_cpucfg_data[2] |= ( + LOONGSON_CFG3_LCAM_REV1 | + LOONGSON_CFG3_LCAMNUM_REV1 | + LOONGSON_CFG3_LCAMKW_REV1 | + LOONGSON_CFG3_LCAMVW_REV1); + break; + + case PRID_REV_LOONGSON3B_R1: + case PRID_REV_LOONGSON3B_R2: + c->loongson3_cpucfg_data[0] |= (LOONGSON_CFG1_LSLDR0 | + LOONGSON_CFG1_LSSYNCI | LOONGSON_CFG1_LSUCA | + LOONGSON_CFG1_LLSYNC | LOONGSON_CFG1_TGTSYNC); + c->loongson3_cpucfg_data[1] |= (LOONGSON_CFG2_LBT1 | + LOONGSON_CFG2_LPMP | LOONGSON_CFG2_LPM_REV1); + c->loongson3_cpucfg_data[2] |= ( + LOONGSON_CFG3_LCAM_REV1 | + LOONGSON_CFG3_LCAMNUM_REV1 | + LOONGSON_CFG3_LCAMKW_REV1 | + LOONGSON_CFG3_LCAMVW_REV1); + break; + + case PRID_REV_LOONGSON2K_R1_0: + case PRID_REV_LOONGSON2K_R1_1: + case PRID_REV_LOONGSON2K_R1_2: + case PRID_REV_LOONGSON2K_R1_3: + decode_loongson_config6(c); + probe_uca(c); + + c->loongson3_cpucfg_data[0] |= (LOONGSON_CFG1_LSLDR0 | + LOONGSON_CFG1_LSSYNCI | LOONGSON_CFG1_LLSYNC | + LOONGSON_CFG1_TGTSYNC); + c->loongson3_cpucfg_data[1] |= (LOONGSON_CFG2_LBT1 | + LOONGSON_CFG2_LBT2 | LOONGSON_CFG2_LPMP | + LOONGSON_CFG2_LPM_REV2); + c->loongson3_cpucfg_data[2] = 0; + break; + + case PRID_REV_LOONGSON3A_R2_0: + case PRID_REV_LOONGSON3A_R2_1: + case PRID_REV_LOONGSON3A_R3_0: + case PRID_REV_LOONGSON3A_R3_1: + decode_loongson_config6(c); + probe_uca(c); + + c->loongson3_cpucfg_data[0] |= (LOONGSON_CFG1_CNT64 | + LOONGSON_CFG1_LSLDR0 | LOONGSON_CFG1_LSPREF | + LOONGSON_CFG1_LSPREFX | LOONGSON_CFG1_LSSYNCI | + LOONGSON_CFG1_LLSYNC | LOONGSON_CFG1_TGTSYNC); + c->loongson3_cpucfg_data[1] |= (LOONGSON_CFG2_LBT1 | + LOONGSON_CFG2_LBT2 | LOONGSON_CFG2_LBTMMU | + LOONGSON_CFG2_LPMP | LOONGSON_CFG2_LPM_REV1 | + LOONGSON_CFG2_LVZ_REV1); + c->loongson3_cpucfg_data[2] |= (LOONGSON_CFG3_LCAM_REV1 | + LOONGSON_CFG3_LCAMNUM_REV1 | + LOONGSON_CFG3_LCAMKW_REV1 | + LOONGSON_CFG3_LCAMVW_REV1); + break; + } + + /* This feature is set by firmware, but all known Loongson-64 systems + * are configured this way. + */ + c->loongson3_cpucfg_data[0] |= LOONGSON_CFG1_CDMAP; + + /* Patch in dynamically probed bits. */ + patch_cpucfg_sel1(c); + patch_cpucfg_sel2(c); + patch_cpucfg_sel3(c); +} |