diff options
Diffstat (limited to '')
| -rw-r--r-- | arch/mips/loongson64/cpucfg-emul.c | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/arch/mips/loongson64/cpucfg-emul.c b/arch/mips/loongson64/cpucfg-emul.c new file mode 100644 index 000000000..630927e46 --- /dev/null +++ b/arch/mips/loongson64/cpucfg-emul.c @@ -0,0 +1,227 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/smp.h> +#include <linux/types.h> +#include <asm/cpu.h> +#include <asm/cpu-info.h> +#include <asm/elf.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 & LOONGSON_CONF6_SFBEN) + c->loongson3_cpucfg_data[0] |= LOONGSON_CFG1_SFBP; + if (config6 & LOONGSON_CONF6_LLEXC) + c->loongson3_cpucfg_data[0] |= LOONGSON_CFG1_LLEXC; + if (config6 & LOONGSON_CONF6_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()) + goto have_cpucfg_now; + + c->loongson3_cpucfg_data[0] = 0; + c->loongson3_cpucfg_data[1] = 0; + c->loongson3_cpucfg_data[2] = 0; + + /* Add CPUCFG features non-discoverable otherwise. */ + switch (c->processor_id & (PRID_IMP_MASK | PRID_REV_MASK)) { + case PRID_IMP_LOONGSON_64R | PRID_REV_LOONGSON2K_R1_0: + case PRID_IMP_LOONGSON_64R | PRID_REV_LOONGSON2K_R1_1: + case PRID_IMP_LOONGSON_64R | PRID_REV_LOONGSON2K_R1_2: + case PRID_IMP_LOONGSON_64R | 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_IMP_LOONGSON_64C | 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_IMP_LOONGSON_64C | PRID_REV_LOONGSON3B_R1: + case PRID_IMP_LOONGSON_64C | 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_IMP_LOONGSON_64C | PRID_REV_LOONGSON3A_R2_0: + case PRID_IMP_LOONGSON_64C | PRID_REV_LOONGSON3A_R2_1: + case PRID_IMP_LOONGSON_64C | PRID_REV_LOONGSON3A_R3_0: + case PRID_IMP_LOONGSON_64C | 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; + + default: + /* It is possible that some future Loongson cores still do + * not have CPUCFG, so do not emulate anything for these + * cores. + */ + return; + } + + /* 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); + +have_cpucfg_now: + /* We have usable CPUCFG now, emulated or not. + * Announce CPUCFG availability to userspace via hwcap. + */ + elf_hwcap |= HWCAP_LOONGSON_CPUCFG; +} |