// SPDX-License-Identifier: GPL-2.0-only /* * Copied from arch/arm64/kernel/cpufeature.c * * Copyright (C) 2015 ARM Ltd. * Copyright (C) 2017 SiFive */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define NUM_ALPHA_EXTS ('z' - 'a' + 1) static bool any_cpu_has_zicboz; unsigned long elf_hwcap __read_mostly; /* Host ISA bitmap */ static DECLARE_BITMAP(riscv_isa, RISCV_ISA_EXT_MAX) __read_mostly; /* Per-cpu ISA extensions. */ struct riscv_isainfo hart_isa[NR_CPUS]; /** * riscv_isa_extension_base() - Get base extension word * * @isa_bitmap: ISA bitmap to use * Return: base extension word as unsigned long value * * NOTE: If isa_bitmap is NULL then Host ISA bitmap will be used. */ unsigned long riscv_isa_extension_base(const unsigned long *isa_bitmap) { if (!isa_bitmap) return riscv_isa[0]; return isa_bitmap[0]; } EXPORT_SYMBOL_GPL(riscv_isa_extension_base); /** * __riscv_isa_extension_available() - Check whether given extension * is available or not * * @isa_bitmap: ISA bitmap to use * @bit: bit position of the desired extension * Return: true or false * * NOTE: If isa_bitmap is NULL then Host ISA bitmap will be used. */ bool __riscv_isa_extension_available(const unsigned long *isa_bitmap, unsigned int bit) { const unsigned long *bmap = (isa_bitmap) ? isa_bitmap : riscv_isa; if (bit >= RISCV_ISA_EXT_MAX) return false; return test_bit(bit, bmap) ? true : false; } EXPORT_SYMBOL_GPL(__riscv_isa_extension_available); static int riscv_ext_zicbom_validate(const struct riscv_isa_ext_data *data, const unsigned long *isa_bitmap) { if (!riscv_cbom_block_size) { pr_err("Zicbom detected in ISA string, disabling as no cbom-block-size found\n"); return -EINVAL; } if (!is_power_of_2(riscv_cbom_block_size)) { pr_err("Zicbom disabled as cbom-block-size present, but is not a power-of-2\n"); return -EINVAL; } return 0; } static int riscv_ext_zicboz_validate(const struct riscv_isa_ext_data *data, const unsigned long *isa_bitmap) { if (!riscv_cboz_block_size) { pr_err("Zicboz detected in ISA string, disabling as no cboz-block-size found\n"); return -EINVAL; } if (!is_power_of_2(riscv_cboz_block_size)) { pr_err("Zicboz disabled as cboz-block-size present, but is not a power-of-2\n"); return -EINVAL; } any_cpu_has_zicboz = true; return 0; } static int riscv_ext_zca_depends(const struct riscv_isa_ext_data *data, const unsigned long *isa_bitmap) { if (__riscv_isa_extension_available(isa_bitmap, RISCV_ISA_EXT_ZCA)) return 0; return -EPROBE_DEFER; } static int riscv_ext_zcd_validate(const struct riscv_isa_ext_data *data, const unsigned long *isa_bitmap) { if (__riscv_isa_extension_available(isa_bitmap, RISCV_ISA_EXT_ZCA) && __riscv_isa_extension_available(isa_bitmap, RISCV_ISA_EXT_d)) return 0; return -EPROBE_DEFER; } static int riscv_ext_zcf_validate(const struct riscv_isa_ext_data *data, const unsigned long *isa_bitmap) { if (IS_ENABLED(CONFIG_64BIT)) return -EINVAL; if (__riscv_isa_extension_available(isa_bitmap, RISCV_ISA_EXT_ZCA) && __riscv_isa_extension_available(isa_bitmap, RISCV_ISA_EXT_f)) return 0; return -EPROBE_DEFER; } static int riscv_ext_svadu_validate(const struct riscv_isa_ext_data *data, const unsigned long *isa_bitmap) { /* SVADE has already been detected, use SVADE only */ if (__riscv_isa_extension_available(isa_bitmap, RISCV_ISA_EXT_SVADE)) return -EOPNOTSUPP; return 0; } static const unsigned int riscv_zk_bundled_exts[] = { RISCV_ISA_EXT_ZBKB, RISCV_ISA_EXT_ZBKC, RISCV_ISA_EXT_ZBKX, RISCV_ISA_EXT_ZKND, RISCV_ISA_EXT_ZKNE, RISCV_ISA_EXT_ZKR, RISCV_ISA_EXT_ZKT, }; static const unsigned int riscv_zkn_bundled_exts[] = { RISCV_ISA_EXT_ZBKB, RISCV_ISA_EXT_ZBKC, RISCV_ISA_EXT_ZBKX, RISCV_ISA_EXT_ZKND, RISCV_ISA_EXT_ZKNE, RISCV_ISA_EXT_ZKNH, }; static const unsigned int riscv_zks_bundled_exts[] = { RISCV_ISA_EXT_ZBKB, RISCV_ISA_EXT_ZBKC, RISCV_ISA_EXT_ZKSED, RISCV_ISA_EXT_ZKSH }; #define RISCV_ISA_EXT_ZVKN \ RISCV_ISA_EXT_ZVKNED, \ RISCV_ISA_EXT_ZVKNHB, \ RISCV_ISA_EXT_ZVKB, \ RISCV_ISA_EXT_ZVKT static const unsigned int riscv_zvkn_bundled_exts[] = { RISCV_ISA_EXT_ZVKN }; static const unsigned int riscv_zvknc_bundled_exts[] = { RISCV_ISA_EXT_ZVKN, RISCV_ISA_EXT_ZVBC }; static const unsigned int riscv_zvkng_bundled_exts[] = { RISCV_ISA_EXT_ZVKN, RISCV_ISA_EXT_ZVKG }; #define RISCV_ISA_EXT_ZVKS \ RISCV_ISA_EXT_ZVKSED, \ RISCV_ISA_EXT_ZVKSH, \ RISCV_ISA_EXT_ZVKB, \ RISCV_ISA_EXT_ZVKT static const unsigned int riscv_zvks_bundled_exts[] = { RISCV_ISA_EXT_ZVKS }; static const unsigned int riscv_zvksc_bundled_exts[] = { RISCV_ISA_EXT_ZVKS, RISCV_ISA_EXT_ZVBC }; static const unsigned int riscv_zvksg_bundled_exts[] = { RISCV_ISA_EXT_ZVKS, RISCV_ISA_EXT_ZVKG }; static const unsigned int riscv_zvbb_exts[] = { RISCV_ISA_EXT_ZVKB }; #define RISCV_ISA_EXT_ZVE64F_IMPLY_LIST \ RISCV_ISA_EXT_ZVE64X, \ RISCV_ISA_EXT_ZVE32F, \ RISCV_ISA_EXT_ZVE32X #define RISCV_ISA_EXT_ZVE64D_IMPLY_LIST \ RISCV_ISA_EXT_ZVE64F, \ RISCV_ISA_EXT_ZVE64F_IMPLY_LIST #define RISCV_ISA_EXT_V_IMPLY_LIST \ RISCV_ISA_EXT_ZVE64D, \ RISCV_ISA_EXT_ZVE64D_IMPLY_LIST static const unsigned int riscv_zve32f_exts[] = { RISCV_ISA_EXT_ZVE32X }; static const unsigned int riscv_zve64f_exts[] = { RISCV_ISA_EXT_ZVE64F_IMPLY_LIST }; static const unsigned int riscv_zve64d_exts[] = { RISCV_ISA_EXT_ZVE64D_IMPLY_LIST }; static const unsigned int riscv_v_exts[] = { RISCV_ISA_EXT_V_IMPLY_LIST }; static const unsigned int riscv_zve64x_exts[] = { RISCV_ISA_EXT_ZVE32X, RISCV_ISA_EXT_ZVE64X }; /* * While the [ms]envcfg CSRs were not defined until version 1.12 of the RISC-V * privileged ISA, the existence of the CSRs is implied by any extension which * specifies [ms]envcfg bit(s). Hence, we define a custom ISA extension for the * existence of the CSR, and treat it as a subset of those other extensions. */ static const unsigned int riscv_xlinuxenvcfg_exts[] = { RISCV_ISA_EXT_XLINUXENVCFG }; /* * Zc* spec states that: * - C always implies Zca * - C+F implies Zcf (RV32 only) * - C+D implies Zcd * * These extensions will be enabled and then validated depending on the * availability of F/D RV32. */ static const unsigned int riscv_c_exts[] = { RISCV_ISA_EXT_ZCA, RISCV_ISA_EXT_ZCF, RISCV_ISA_EXT_ZCD, }; /* * The canonical order of ISA extension names in the ISA string is defined in * chapter 27 of the unprivileged specification. * * Ordinarily, for in-kernel data structures, this order is unimportant but * isa_ext_arr defines the order of the ISA string in /proc/cpuinfo. * * The specification uses vague wording, such as should, when it comes to * ordering, so for our purposes the following rules apply: * * 1. All multi-letter extensions must be separated from other extensions by an * underscore. * * 2. Additional standard extensions (starting with 'Z') must be sorted after * single-letter extensions and before any higher-privileged extensions. * * 3. The first letter following the 'Z' conventionally indicates the most * closely related alphabetical extension category, IMAFDQLCBKJTPVH. * If multiple 'Z' extensions are named, they must be ordered first by * category, then alphabetically within a category. * * 3. Standard supervisor-level extensions (starting with 'S') must be listed * after standard unprivileged extensions. If multiple supervisor-level * extensions are listed, they must be ordered alphabetically. * * 4. Standard machine-level extensions (starting with 'Zxm') must be listed * after any lower-privileged, standard extensions. If multiple * machine-level extensions are listed, they must be ordered * alphabetically. * * 5. Non-standard extensions (starting with 'X') must be listed after all * standard extensions. If multiple non-standard extensions are listed, they * must be ordered alphabetically. * * An example string following the order is: * rv64imadc_zifoo_zigoo_zafoo_sbar_scar_zxmbaz_xqux_xrux * * New entries to this struct should follow the ordering rules described above. */ const struct riscv_isa_ext_data riscv_isa_ext[] = { __RISCV_ISA_EXT_DATA(i, RISCV_ISA_EXT_i), __RISCV_ISA_EXT_DATA(m, RISCV_ISA_EXT_m), __RISCV_ISA_EXT_DATA(a, RISCV_ISA_EXT_a), __RISCV_ISA_EXT_DATA(f, RISCV_ISA_EXT_f), __RISCV_ISA_EXT_DATA(d, RISCV_ISA_EXT_d), __RISCV_ISA_EXT_DATA(q, RISCV_ISA_EXT_q), __RISCV_ISA_EXT_SUPERSET(c, RISCV_ISA_EXT_c, riscv_c_exts), __RISCV_ISA_EXT_SUPERSET(v, RISCV_ISA_EXT_v, riscv_v_exts), __RISCV_ISA_EXT_DATA(h, RISCV_ISA_EXT_h), __RISCV_ISA_EXT_SUPERSET_VALIDATE(zicbom, RISCV_ISA_EXT_ZICBOM, riscv_xlinuxenvcfg_exts, riscv_ext_zicbom_validate), __RISCV_ISA_EXT_SUPERSET_VALIDATE(zicboz, RISCV_ISA_EXT_ZICBOZ, riscv_xlinuxenvcfg_exts, riscv_ext_zicboz_validate), __RISCV_ISA_EXT_DATA(ziccrse, RISCV_ISA_EXT_ZICCRSE), __RISCV_ISA_EXT_DATA(zicntr, RISCV_ISA_EXT_ZICNTR), __RISCV_ISA_EXT_DATA(zicond, RISCV_ISA_EXT_ZICOND), __RISCV_ISA_EXT_DATA(zicsr, RISCV_ISA_EXT_ZICSR), __RISCV_ISA_EXT_DATA(zifencei, RISCV_ISA_EXT_ZIFENCEI), __RISCV_ISA_EXT_DATA(zihintntl, RISCV_ISA_EXT_ZIHINTNTL), __RISCV_ISA_EXT_DATA(zihintpause, RISCV_ISA_EXT_ZIHINTPAUSE), __RISCV_ISA_EXT_DATA(zihpm, RISCV_ISA_EXT_ZIHPM), __RISCV_ISA_EXT_DATA(zimop, RISCV_ISA_EXT_ZIMOP), __RISCV_ISA_EXT_DATA(zabha, RISCV_ISA_EXT_ZABHA), __RISCV_ISA_EXT_DATA(zacas, RISCV_ISA_EXT_ZACAS), __RISCV_ISA_EXT_DATA(zawrs, RISCV_ISA_EXT_ZAWRS), __RISCV_ISA_EXT_DATA(zfa, RISCV_ISA_EXT_ZFA), __RISCV_ISA_EXT_DATA(zfh, RISCV_ISA_EXT_ZFH), __RISCV_ISA_EXT_DATA(zfhmin, RISCV_ISA_EXT_ZFHMIN), __RISCV_ISA_EXT_DATA(zca, RISCV_ISA_EXT_ZCA), __RISCV_ISA_EXT_DATA_VALIDATE(zcb, RISCV_ISA_EXT_ZCB, riscv_ext_zca_depends), __RISCV_ISA_EXT_DATA_VALIDATE(zcd, RISCV_ISA_EXT_ZCD, riscv_ext_zcd_validate), __RISCV_ISA_EXT_DATA_VALIDATE(zcf, RISCV_ISA_EXT_ZCF, riscv_ext_zcf_validate), __RISCV_ISA_EXT_DATA_VALIDATE(zcmop, RISCV_ISA_EXT_ZCMOP, riscv_ext_zca_depends), __RISCV_ISA_EXT_DATA(zba, RISCV_ISA_EXT_ZBA), __RISCV_ISA_EXT_DATA(zbb, RISCV_ISA_EXT_ZBB), __RISCV_ISA_EXT_DATA(zbc, RISCV_ISA_EXT_ZBC), __RISCV_ISA_EXT_DATA(zbkb, RISCV_ISA_EXT_ZBKB), __RISCV_ISA_EXT_DATA(zbkc, RISCV_ISA_EXT_ZBKC), __RISCV_ISA_EXT_DATA(zbkx, RISCV_ISA_EXT_ZBKX), __RISCV_ISA_EXT_DATA(zbs, RISCV_ISA_EXT_ZBS), __RISCV_ISA_EXT_BUNDLE(zk, riscv_zk_bundled_exts), __RISCV_ISA_EXT_BUNDLE(zkn, riscv_zkn_bundled_exts), __RISCV_ISA_EXT_DATA(zknd, RISCV_ISA_EXT_ZKND), __RISCV_ISA_EXT_DATA(zkne, RISCV_ISA_EXT_ZKNE), __RISCV_ISA_EXT_DATA(zknh, RISCV_ISA_EXT_ZKNH), __RISCV_ISA_EXT_DATA(zkr, RISCV_ISA_EXT_ZKR), __RISCV_ISA_EXT_BUNDLE(zks, riscv_zks_bundled_exts), __RISCV_ISA_EXT_DATA(zkt, RISCV_ISA_EXT_ZKT), __RISCV_ISA_EXT_DATA(zksed, RISCV_ISA_EXT_ZKSED), __RISCV_ISA_EXT_DATA(zksh, RISCV_ISA_EXT_ZKSH), __RISCV_ISA_EXT_DATA(ztso, RISCV_ISA_EXT_ZTSO), __RISCV_ISA_EXT_SUPERSET(zvbb, RISCV_ISA_EXT_ZVBB, riscv_zvbb_exts), __RISCV_ISA_EXT_DATA(zvbc, RISCV_ISA_EXT_ZVBC), __RISCV_ISA_EXT_SUPERSET(zve32f, RISCV_ISA_EXT_ZVE32F, riscv_zve32f_exts), __RISCV_ISA_EXT_DATA(zve32x, RISCV_ISA_EXT_ZVE32X), __RISCV_ISA_EXT_SUPERSET(zve64d, RISCV_ISA_EXT_ZVE64D, riscv_zve64d_exts), __RISCV_ISA_EXT_SUPERSET(zve64f, RISCV_ISA_EXT_ZVE64F, riscv_zve64f_exts), __RISCV_ISA_EXT_SUPERSET(zve64x, RISCV_ISA_EXT_ZVE64X, riscv_zve64x_exts), __RISCV_ISA_EXT_DATA(zvfh, RISCV_ISA_EXT_ZVFH), __RISCV_ISA_EXT_DATA(zvfhmin, RISCV_ISA_EXT_ZVFHMIN), __RISCV_ISA_EXT_DATA(zvkb, RISCV_ISA_EXT_ZVKB), __RISCV_ISA_EXT_DATA(zvkg, RISCV_ISA_EXT_ZVKG), __RISCV_ISA_EXT_BUNDLE(zvkn, riscv_zvkn_bundled_exts), __RISCV_ISA_EXT_BUNDLE(zvknc, riscv_zvknc_bundled_exts), __RISCV_ISA_EXT_DATA(zvkned, RISCV_ISA_EXT_ZVKNED), __RISCV_ISA_EXT_BUNDLE(zvkng, riscv_zvkng_bundled_exts), __RISCV_ISA_EXT_DATA(zvknha, RISCV_ISA_EXT_ZVKNHA), __RISCV_ISA_EXT_DATA(zvknhb, RISCV_ISA_EXT_ZVKNHB), __RISCV_ISA_EXT_BUNDLE(zvks, riscv_zvks_bundled_exts), __RISCV_ISA_EXT_BUNDLE(zvksc, riscv_zvksc_bundled_exts), __RISCV_ISA_EXT_DATA(zvksed, RISCV_ISA_EXT_ZVKSED), __RISCV_ISA_EXT_DATA(zvksh, RISCV_ISA_EXT_ZVKSH), __RISCV_ISA_EXT_BUNDLE(zvksg, riscv_zvksg_bundled_exts), __RISCV_ISA_EXT_DATA(zvkt, RISCV_ISA_EXT_ZVKT), __RISCV_ISA_EXT_DATA(smaia, RISCV_ISA_EXT_SMAIA), __RISCV_ISA_EXT_DATA(smmpm, RISCV_ISA_EXT_SMMPM), __RISCV_ISA_EXT_SUPERSET(smnpm, RISCV_ISA_EXT_SMNPM, riscv_xlinuxenvcfg_exts), __RISCV_ISA_EXT_DATA(smstateen, RISCV_ISA_EXT_SMSTATEEN), __RISCV_ISA_EXT_DATA(ssaia, RISCV_ISA_EXT_SSAIA), __RISCV_ISA_EXT_DATA(sscofpmf, RISCV_ISA_EXT_SSCOFPMF), __RISCV_ISA_EXT_SUPERSET(ssnpm, RISCV_ISA_EXT_SSNPM, riscv_xlinuxenvcfg_exts), __RISCV_ISA_EXT_DATA(sstc, RISCV_ISA_EXT_SSTC), __RISCV_ISA_EXT_DATA(svade, RISCV_ISA_EXT_SVADE), __RISCV_ISA_EXT_DATA_VALIDATE(svadu, RISCV_ISA_EXT_SVADU, riscv_ext_svadu_validate), __RISCV_ISA_EXT_DATA(svinval, RISCV_ISA_EXT_SVINVAL), __RISCV_ISA_EXT_DATA(svnapot, RISCV_ISA_EXT_SVNAPOT), __RISCV_ISA_EXT_DATA(svpbmt, RISCV_ISA_EXT_SVPBMT), __RISCV_ISA_EXT_DATA(svvptc, RISCV_ISA_EXT_SVVPTC), }; const size_t riscv_isa_ext_count = ARRAY_SIZE(riscv_isa_ext); static void riscv_isa_set_ext(const struct riscv_isa_ext_data *ext, unsigned long *bitmap) { if (ext->id != RISCV_ISA_EXT_INVALID) set_bit(ext->id, bitmap); for (int i = 0; i < ext->subset_ext_size; i++) { if (ext->subset_ext_ids[i] != RISCV_ISA_EXT_INVALID) set_bit(ext->subset_ext_ids[i], bitmap); } } static const struct riscv_isa_ext_data *riscv_get_isa_ext_data(unsigned int ext_id) { for (int i = 0; i < riscv_isa_ext_count; i++) { if (riscv_isa_ext[i].id == ext_id) return &riscv_isa_ext[i]; } return NULL; } /* * "Resolve" a source ISA bitmap into one that matches kernel configuration as * well as correct extension dependencies. Some extensions depends on specific * kernel configuration to be usable (V needs CONFIG_RISCV_ISA_V for instance) * and this function will actually validate all the extensions provided in * source_isa into the resolved_isa based on extensions validate() callbacks. */ static void __init riscv_resolve_isa(unsigned long *source_isa, unsigned long *resolved_isa, unsigned long *this_hwcap, unsigned long *isa2hwcap) { bool loop; const struct riscv_isa_ext_data *ext; DECLARE_BITMAP(prev_resolved_isa, RISCV_ISA_EXT_MAX); int max_loop_count = riscv_isa_ext_count, ret; unsigned int bit; do { loop = false; if (max_loop_count-- < 0) { pr_err("Failed to reach a stable ISA state\n"); return; } bitmap_copy(prev_resolved_isa, resolved_isa, RISCV_ISA_EXT_MAX); for_each_set_bit(bit, source_isa, RISCV_ISA_EXT_MAX) { ext = riscv_get_isa_ext_data(bit); if (ext && ext->validate) { ret = ext->validate(ext, resolved_isa); if (ret == -EPROBE_DEFER) { loop = true; continue; } else if (ret) { /* Disable the extension entirely */ clear_bit(bit, source_isa); continue; } } set_bit(bit, resolved_isa); /* No need to keep it in source isa now that it is enabled */ clear_bit(bit, source_isa); /* Single letter extensions get set in hwcap */ if (bit < RISCV_ISA_EXT_BASE) *this_hwcap |= isa2hwcap[bit]; } } while (loop && memcmp(prev_resolved_isa, resolved_isa, sizeof(prev_resolved_isa))); } static void __init match_isa_ext(const char *name, const char *name_end, unsigned long *bitmap) { for (int i = 0; i < riscv_isa_ext_count; i++) { const struct riscv_isa_ext_data *ext = &riscv_isa_ext[i]; if ((name_end - name == strlen(ext->name)) && !strncasecmp(name, ext->name, name_end - name)) { riscv_isa_set_ext(ext, bitmap); break; } } } static void __init riscv_parse_isa_string(const char *isa, unsigned long *bitmap) { /* * For all possible cpus, we have already validated in * the boot process that they at least contain "rv" and * whichever of "32"/"64" this kernel supports, and so this * section can be skipped. */ isa += 4; while (*isa) { const char *ext = isa++; const char *ext_end = isa; bool ext_err = false; switch (*ext) { case 'x': case 'X': if (acpi_disabled) pr_warn_once("Vendor extensions are ignored in riscv,isa. Use riscv,isa-extensions instead."); /* * To skip an extension, we find its end. * As multi-letter extensions must be split from other multi-letter * extensions with an "_", the end of a multi-letter extension will * either be the null character or the "_" at the start of the next * multi-letter extension. */ for (; *isa && *isa != '_'; ++isa) ; ext_err = true; break; case 's': /* * Workaround for invalid single-letter 's' & 'u' (QEMU). * No need to set the bit in riscv_isa as 's' & 'u' are * not valid ISA extensions. It works unless the first * multi-letter extension in the ISA string begins with * "Su" and is not prefixed with an underscore. */ if (ext[-1] != '_' && ext[1] == 'u') { ++isa; ext_err = true; break; } fallthrough; case 'S': case 'z': case 'Z': /* * Before attempting to parse the extension itself, we find its end. * As multi-letter extensions must be split from other multi-letter * extensions with an "_", the end of a multi-letter extension will * either be the null character or the "_" at the start of the next * multi-letter extension. * * Next, as the extensions version is currently ignored, we * eliminate that portion. This is done by parsing backwards from * the end of the extension, removing any numbers. This may be a * major or minor number however, so the process is repeated if a * minor number was found. * * ext_end is intended to represent the first character *after* the * name portion of an extension, but will be decremented to the last * character itself while eliminating the extensions version number. * A simple re-increment solves this problem. */ for (; *isa && *isa != '_'; ++isa) if (unlikely(!isalnum(*isa))) ext_err = true; ext_end = isa; if (unlikely(ext_err)) break; if (!isdigit(ext_end[-1])) break; while (isdigit(*--ext_end)) ; if (tolower(ext_end[0]) != 'p' || !isdigit(ext_end[-1])) { ++ext_end; break; } while (isdigit(*--ext_end)) ; ++ext_end; break; default: /* * Things are a little easier for single-letter extensions, as they * are parsed forwards. * * After checking that our starting position is valid, we need to * ensure that, when isa was incremented at the start of the loop, * that it arrived at the start of the next extension. * * If we are already on a non-digit, there is nothing to do. Either * we have a multi-letter extension's _, or the start of an * extension. * * Otherwise we have found the current extension's major version * number. Parse past it, and a subsequent p/minor version number * if present. The `p` extension must not appear immediately after * a number, so there is no fear of missing it. * */ if (unlikely(!isalpha(*ext))) { ext_err = true; break; } if (!isdigit(*isa)) break; while (isdigit(*++isa)) ; if (tolower(*isa) != 'p') break; if (!isdigit(*++isa)) { --isa; break; } while (isdigit(*++isa)) ; break; } /* * The parser expects that at the start of an iteration isa points to the * first character of the next extension. As we stop parsing an extension * on meeting a non-alphanumeric character, an extra increment is needed * where the succeeding extension is a multi-letter prefixed with an "_". */ if (*isa == '_') ++isa; if (unlikely(ext_err)) continue; match_isa_ext(ext, ext_end, bitmap); } } static void __init riscv_fill_hwcap_from_isa_string(unsigned long *isa2hwcap) { struct device_node *node; const char *isa; int rc; struct acpi_table_header *rhct; acpi_status status; unsigned int cpu; u64 boot_vendorid; u64 boot_archid; if (!acpi_disabled) { status = acpi_get_table(ACPI_SIG_RHCT, 0, &rhct); if (ACPI_FAILURE(status)) return; } boot_vendorid = riscv_get_mvendorid(); boot_archid = riscv_get_marchid(); for_each_possible_cpu(cpu) { struct riscv_isainfo *isainfo = &hart_isa[cpu]; unsigned long this_hwcap = 0; DECLARE_BITMAP(source_isa, RISCV_ISA_EXT_MAX) = { 0 }; if (acpi_disabled) { node = of_cpu_device_node_get(cpu); if (!node) { pr_warn("Unable to find cpu node\n"); continue; } rc = of_property_read_string(node, "riscv,isa", &isa); of_node_put(node); if (rc) { pr_warn("Unable to find \"riscv,isa\" devicetree entry\n"); continue; } } else { rc = acpi_get_riscv_isa(rhct, cpu, &isa); if (rc < 0) { pr_warn("Unable to get ISA for the hart - %d\n", cpu); continue; } } riscv_parse_isa_string(isa, source_isa); /* * These ones were as they were part of the base ISA when the * port & dt-bindings were upstreamed, and so can be set * unconditionally where `i` is in riscv,isa on DT systems. */ if (acpi_disabled) { set_bit(RISCV_ISA_EXT_ZICSR, source_isa); set_bit(RISCV_ISA_EXT_ZIFENCEI, source_isa); set_bit(RISCV_ISA_EXT_ZICNTR, source_isa); set_bit(RISCV_ISA_EXT_ZIHPM, source_isa); } /* * "V" in ISA strings is ambiguous in practice: it should mean * just the standard V-1.0 but vendors aren't well behaved. * Many vendors with T-Head CPU cores which implement the 0.7.1 * version of the vector specification put "v" into their DTs. * CPU cores with the ratified spec will contain non-zero * marchid. */ if (acpi_disabled && boot_vendorid == THEAD_VENDOR_ID && boot_archid == 0x0) { this_hwcap &= ~isa2hwcap[RISCV_ISA_EXT_v]; clear_bit(RISCV_ISA_EXT_v, source_isa); } riscv_resolve_isa(source_isa, isainfo->isa, &this_hwcap, isa2hwcap); /* * All "okay" hart should have same isa. Set HWCAP based on * common capabilities of every "okay" hart, in case they don't * have. */ if (elf_hwcap) elf_hwcap &= this_hwcap; else elf_hwcap = this_hwcap; if (bitmap_empty(riscv_isa, RISCV_ISA_EXT_MAX)) bitmap_copy(riscv_isa, isainfo->isa, RISCV_ISA_EXT_MAX); else bitmap_and(riscv_isa, riscv_isa, isainfo->isa, RISCV_ISA_EXT_MAX); } if (!acpi_disabled && rhct) acpi_put_table((struct acpi_table_header *)rhct); } static void __init riscv_fill_cpu_vendor_ext(struct device_node *cpu_node, int cpu) { if (!IS_ENABLED(CONFIG_RISCV_ISA_VENDOR_EXT)) return; for (int i = 0; i < riscv_isa_vendor_ext_list_size; i++) { struct riscv_isa_vendor_ext_data_list *ext_list = riscv_isa_vendor_ext_list[i]; for (int j = 0; j < ext_list->ext_data_count; j++) { const struct riscv_isa_ext_data ext = ext_list->ext_data[j]; struct riscv_isavendorinfo *isavendorinfo = &ext_list->per_hart_isa_bitmap[cpu]; if (of_property_match_string(cpu_node, "riscv,isa-extensions", ext.property) < 0) continue; /* * Assume that subset extensions are all members of the * same vendor. */ if (ext.subset_ext_size) for (int k = 0; k < ext.subset_ext_size; k++) set_bit(ext.subset_ext_ids[k], isavendorinfo->isa); set_bit(ext.id, isavendorinfo->isa); } } } /* * Populate all_harts_isa_bitmap for each vendor with all of the extensions that * are shared across CPUs for that vendor. */ static void __init riscv_fill_vendor_ext_list(int cpu) { if (!IS_ENABLED(CONFIG_RISCV_ISA_VENDOR_EXT)) return; for (int i = 0; i < riscv_isa_vendor_ext_list_size; i++) { struct riscv_isa_vendor_ext_data_list *ext_list = riscv_isa_vendor_ext_list[i]; if (!ext_list->is_initialized) { bitmap_copy(ext_list->all_harts_isa_bitmap.isa, ext_list->per_hart_isa_bitmap[cpu].isa, RISCV_ISA_VENDOR_EXT_MAX); ext_list->is_initialized = true; } else { bitmap_and(ext_list->all_harts_isa_bitmap.isa, ext_list->all_harts_isa_bitmap.isa, ext_list->per_hart_isa_bitmap[cpu].isa, RISCV_ISA_VENDOR_EXT_MAX); } } } static int __init riscv_fill_hwcap_from_ext_list(unsigned long *isa2hwcap) { unsigned int cpu; for_each_possible_cpu(cpu) { unsigned long this_hwcap = 0; struct device_node *cpu_node; struct riscv_isainfo *isainfo = &hart_isa[cpu]; DECLARE_BITMAP(source_isa, RISCV_ISA_EXT_MAX) = { 0 }; cpu_node = of_cpu_device_node_get(cpu); if (!cpu_node) { pr_warn("Unable to find cpu node\n"); continue; } if (!of_property_present(cpu_node, "riscv,isa-extensions")) { of_node_put(cpu_node); continue; } for (int i = 0; i < riscv_isa_ext_count; i++) { const struct riscv_isa_ext_data *ext = &riscv_isa_ext[i]; if (of_property_match_string(cpu_node, "riscv,isa-extensions", ext->property) < 0) continue; riscv_isa_set_ext(ext, source_isa); } riscv_resolve_isa(source_isa, isainfo->isa, &this_hwcap, isa2hwcap); riscv_fill_cpu_vendor_ext(cpu_node, cpu); of_node_put(cpu_node); /* * All "okay" harts should have same isa. Set HWCAP based on * common capabilities of every "okay" hart, in case they don't. */ if (elf_hwcap) elf_hwcap &= this_hwcap; else elf_hwcap = this_hwcap; if (bitmap_empty(riscv_isa, RISCV_ISA_EXT_MAX)) bitmap_copy(riscv_isa, isainfo->isa, RISCV_ISA_EXT_MAX); else bitmap_and(riscv_isa, riscv_isa, isainfo->isa, RISCV_ISA_EXT_MAX); riscv_fill_vendor_ext_list(cpu); } if (bitmap_empty(riscv_isa, RISCV_ISA_EXT_MAX)) return -ENOENT; return 0; } #ifdef CONFIG_RISCV_ISA_FALLBACK bool __initdata riscv_isa_fallback = true; #else bool __initdata riscv_isa_fallback; static int __init riscv_isa_fallback_setup(char *__unused) { riscv_isa_fallback = true; return 1; } early_param("riscv_isa_fallback", riscv_isa_fallback_setup); #endif void __init riscv_fill_hwcap(void) { char print_str[NUM_ALPHA_EXTS + 1]; unsigned long isa2hwcap[26] = {0}; int i, j; isa2hwcap['i' - 'a'] = COMPAT_HWCAP_ISA_I; isa2hwcap['m' - 'a'] = COMPAT_HWCAP_ISA_M; isa2hwcap['a' - 'a'] = COMPAT_HWCAP_ISA_A; isa2hwcap['f' - 'a'] = COMPAT_HWCAP_ISA_F; isa2hwcap['d' - 'a'] = COMPAT_HWCAP_ISA_D; isa2hwcap['c' - 'a'] = COMPAT_HWCAP_ISA_C; isa2hwcap['v' - 'a'] = COMPAT_HWCAP_ISA_V; if (!acpi_disabled) { riscv_fill_hwcap_from_isa_string(isa2hwcap); } else { int ret = riscv_fill_hwcap_from_ext_list(isa2hwcap); if (ret && riscv_isa_fallback) { pr_info("Falling back to deprecated \"riscv,isa\"\n"); riscv_fill_hwcap_from_isa_string(isa2hwcap); } } /* * We don't support systems with F but without D, so mask those out * here. */ if ((elf_hwcap & COMPAT_HWCAP_ISA_F) && !(elf_hwcap & COMPAT_HWCAP_ISA_D)) { pr_info("This kernel does not support systems with F but not D\n"); elf_hwcap &= ~COMPAT_HWCAP_ISA_F; } if (__riscv_isa_extension_available(NULL, RISCV_ISA_EXT_ZVE32X)) { /* * This cannot fail when called on the boot hart */ riscv_v_setup_vsize(); } if (elf_hwcap & COMPAT_HWCAP_ISA_V) { /* * ISA string in device tree might have 'v' flag, but * CONFIG_RISCV_ISA_V is disabled in kernel. * Clear V flag in elf_hwcap if CONFIG_RISCV_ISA_V is disabled. */ if (!IS_ENABLED(CONFIG_RISCV_ISA_V)) elf_hwcap &= ~COMPAT_HWCAP_ISA_V; } memset(print_str, 0, sizeof(print_str)); for (i = 0, j = 0; i < NUM_ALPHA_EXTS; i++) if (riscv_isa[0] & BIT_MASK(i)) print_str[j++] = (char)('a' + i); pr_info("riscv: base ISA extensions %s\n", print_str); memset(print_str, 0, sizeof(print_str)); for (i = 0, j = 0; i < NUM_ALPHA_EXTS; i++) if (elf_hwcap & BIT_MASK(i)) print_str[j++] = (char)('a' + i); pr_info("riscv: ELF capabilities %s\n", print_str); } unsigned long riscv_get_elf_hwcap(void) { unsigned long hwcap; hwcap = (elf_hwcap & ((1UL << RISCV_ISA_EXT_BASE) - 1)); if (!riscv_v_vstate_ctrl_user_allowed()) hwcap &= ~COMPAT_HWCAP_ISA_V; return hwcap; } void __init riscv_user_isa_enable(void) { if (riscv_has_extension_unlikely(RISCV_ISA_EXT_ZICBOZ)) current->thread.envcfg |= ENVCFG_CBZE; else if (any_cpu_has_zicboz) pr_warn("Zicboz disabled as it is unavailable on some harts\n"); } #ifdef CONFIG_RISCV_ALTERNATIVE /* * Alternative patch sites consider 48 bits when determining when to patch * the old instruction sequence with the new. These bits are broken into a * 16-bit vendor ID and a 32-bit patch ID. A non-zero vendor ID means the * patch site is for an erratum, identified by the 32-bit patch ID. When * the vendor ID is zero, the patch site is for a cpufeature. cpufeatures * further break down patch ID into two 16-bit numbers. The lower 16 bits * are the cpufeature ID and the upper 16 bits are used for a value specific * to the cpufeature and patch site. If the upper 16 bits are zero, then it * implies no specific value is specified. cpufeatures that want to control * patching on a per-site basis will provide non-zero values and implement * checks here. The checks return true when patching should be done, and * false otherwise. */ static bool riscv_cpufeature_patch_check(u16 id, u16 value) { if (!value) return true; switch (id) { case RISCV_ISA_EXT_ZICBOZ: /* * Zicboz alternative applications provide the maximum * supported block size order, or zero when it doesn't * matter. If the current block size exceeds the maximum, * then the alternative cannot be applied. */ return riscv_cboz_block_size <= (1U << value); } return false; } void __init_or_module riscv_cpufeature_patch_func(struct alt_entry *begin, struct alt_entry *end, unsigned int stage) { struct alt_entry *alt; void *oldptr, *altptr; u16 id, value, vendor; if (stage == RISCV_ALTERNATIVES_EARLY_BOOT) return; for (alt = begin; alt < end; alt++) { id = PATCH_ID_CPUFEATURE_ID(alt->patch_id); vendor = PATCH_ID_CPUFEATURE_ID(alt->vendor_id); /* * Any alternative with a patch_id that is less than * RISCV_ISA_EXT_MAX is interpreted as a standard extension. * * Any alternative with patch_id that is greater than or equal * to RISCV_VENDOR_EXT_ALTERNATIVES_BASE is interpreted as a * vendor extension. */ if (id < RISCV_ISA_EXT_MAX) { /* * This patch should be treated as errata so skip * processing here. */ if (alt->vendor_id != 0) continue; if (!__riscv_isa_extension_available(NULL, id)) continue; value = PATCH_ID_CPUFEATURE_VALUE(alt->patch_id); if (!riscv_cpufeature_patch_check(id, value)) continue; } else if (id >= RISCV_VENDOR_EXT_ALTERNATIVES_BASE) { if (!__riscv_isa_vendor_extension_available(VENDOR_EXT_ALL_CPUS, vendor, id - RISCV_VENDOR_EXT_ALTERNATIVES_BASE)) continue; } else { WARN(1, "This extension id:%d is not in ISA extension list", id); continue; } oldptr = ALT_OLD_PTR(alt); altptr = ALT_ALT_PTR(alt); mutex_lock(&text_mutex); patch_text_nosync(oldptr, altptr, alt->alt_len); riscv_alternative_fix_offsets(oldptr, alt->alt_len, oldptr - altptr); mutex_unlock(&text_mutex); } } #endif