From 23059893967826467e36c6d9f7428cc79dd48a11 Mon Sep 17 00:00:00 2001 From: Palmer Dabbelt Date: Thu, 13 Jul 2023 13:10:59 +0100 Subject: [PATCH 01/11] RISC-V: Provide a more helpful error message on invalid ISA strings Right now we provide a somewhat unhelpful error message on systems with invalid error messages, something along the lines of CPU with hartid=0 is not available ------------[ cut here ]------------ kernel BUG at arch/riscv/kernel/smpboot.c:174! Kernel BUG [#1] Modules linked in: CPU: 0 PID: 0 Comm: swapper Not tainted 6.4.0-rc1-00096-ge0097d2c62d5-dirty #1 Hardware name: Microchip PolarFire-SoC Icicle Kit (DT) epc : of_parse_and_init_cpus+0x16c/0x16e ra : of_parse_and_init_cpus+0x9a/0x16e epc : ffffffff80c04e0a ra : ffffffff80c04d38 sp : ffffffff81603e20 gp : ffffffff8182d658 tp : ffffffff81613f80 t0 : 000000000000006e t1 : 0000000000000064 t2 : 0000000000000000 s0 : ffffffff81603e80 s1 : 0000000000000000 a0 : 0000000000000000 a1 : 0000000000000000 a2 : 0000000000000000 a3 : 0000000000000000 a4 : 0000000000000000 a5 : 0000000000001fff a6 : 0000000000001fff a7 : ffffffff816148b0 s2 : 0000000000000001 s3 : ffffffff81492a4c s4 : ffffffff81a4b090 s5 : ffffffff81506030 s6 : 0000000000000040 s7 : 0000000000000000 s8 : 00000000bfb6f046 s9 : 0000000000000001 s10: 0000000000000000 s11: 00000000bf389700 t3 : 0000000000000000 t4 : 0000000000000000 t5 : ffffffff824dd188 t6 : ffffffff824dd187 status: 0000000200000100 badaddr: 0000000000000000 cause: 0000000000000003 [] of_parse_and_init_cpus+0x16c/0x16e [] setup_smp+0x1e/0x26 [] setup_arch+0x6e/0xb2 [] start_kernel+0x72/0x400 Code: 80e7 4a00 a603 0009 b795 1097 ffe5 80e7 92c0 9002 (9002) 715d ---[ end trace 0000000000000000 ]--- Kernel panic - not syncing: Fatal exception in interrupt Add a warning for the cases where the ISA string isn't valid. It's still above the BUG_ON cut, but hopefully it's at least a bit easier for users. Reviewed-by: Evan Green Reviewed-by: Andrew Jones Signed-off-by: Conor Dooley Link: https://lore.kernel.org/r/20230713-endless-spearhead-62a5a4b149bd@wendy Signed-off-by: Palmer Dabbelt --- arch/riscv/kernel/cpu.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c index a2fc952318e9..3af2d214ce21 100644 --- a/arch/riscv/kernel/cpu.c +++ b/arch/riscv/kernel/cpu.c @@ -66,11 +66,15 @@ int riscv_early_of_processor_hartid(struct device_node *node, unsigned long *har return -ENODEV; } - if (IS_ENABLED(CONFIG_32BIT) && strncasecmp(isa, "rv32ima", 7)) + if (IS_ENABLED(CONFIG_32BIT) && strncasecmp(isa, "rv32ima", 7)) { + pr_warn("CPU with hartid=%lu does not support rv32ima", *hart); return -ENODEV; + } - if (IS_ENABLED(CONFIG_64BIT) && strncasecmp(isa, "rv64ima", 7)) + if (IS_ENABLED(CONFIG_64BIT) && strncasecmp(isa, "rv64ima", 7)) { + pr_warn("CPU with hartid=%lu does not support rv64ima", *hart); return -ENODEV; + } return 0; } From 67270fb388feb3ab7b8f1c8e2825d43237ffa7a0 Mon Sep 17 00:00:00 2001 From: Heiko Stuebner Date: Thu, 13 Jul 2023 13:11:00 +0100 Subject: [PATCH 02/11] RISC-V: don't parse dt/acpi isa string to get rv32/rv64 When filling hwcap the kernel already expects the isa string to start with rv32 if CONFIG_32BIT and rv64 if CONFIG_64BIT. So when recreating the runtime isa-string we can also just go the other way to get the correct starting point for it. Signed-off-by: Heiko Stuebner Reviewed-by: Andrew Jones Reviewed-by: Evan Green Co-developed-by: Conor Dooley Signed-off-by: Conor Dooley Link: https://lore.kernel.org/r/20230713-masculine-saddlebag-67a94966b091@wendy Signed-off-by: Palmer Dabbelt --- arch/riscv/kernel/cpu.c | 21 +++++++++------------ 1 file changed, 9 insertions(+), 12 deletions(-) diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c index 3af2d214ce21..f808b67f5a27 100644 --- a/arch/riscv/kernel/cpu.c +++ b/arch/riscv/kernel/cpu.c @@ -257,13 +257,16 @@ static void print_isa_ext(struct seq_file *f) */ static const char base_riscv_exts[13] = "imafdqcbkjpvh"; -static void print_isa(struct seq_file *f, const char *isa) +static void print_isa(struct seq_file *f) { int i; seq_puts(f, "isa\t\t: "); - /* Print the rv[64/32] part */ - seq_write(f, isa, 4); + if (IS_ENABLED(CONFIG_32BIT)) + seq_write(f, "rv32", 4); + else + seq_write(f, "rv64", 4); + for (i = 0; i < sizeof(base_riscv_exts); i++) { if (__riscv_isa_extension_available(NULL, base_riscv_exts[i] - 'a')) /* Print only enabled the base ISA extensions */ @@ -320,27 +323,21 @@ static int c_show(struct seq_file *m, void *v) unsigned long cpu_id = (unsigned long)v - 1; struct riscv_cpuinfo *ci = per_cpu_ptr(&riscv_cpuinfo, cpu_id); struct device_node *node; - const char *compat, *isa; + const char *compat; seq_printf(m, "processor\t: %lu\n", cpu_id); seq_printf(m, "hart\t\t: %lu\n", cpuid_to_hartid_map(cpu_id)); + print_isa(m); + print_mmu(m); if (acpi_disabled) { node = of_get_cpu_node(cpu_id, NULL); - if (!of_property_read_string(node, "riscv,isa", &isa)) - print_isa(m, isa); - print_mmu(m); if (!of_property_read_string(node, "compatible", &compat) && strcmp(compat, "riscv")) seq_printf(m, "uarch\t\t: %s\n", compat); of_node_put(node); - } else { - if (!acpi_get_riscv_isa(NULL, cpu_id, &isa)) - print_isa(m, isa); - - print_mmu(m); } seq_printf(m, "mvendorid\t: 0x%lx\n", ci->mvendorid); From 131033689da2ce17fb1407f0d3e608a203be5e09 Mon Sep 17 00:00:00 2001 From: Conor Dooley Date: Thu, 13 Jul 2023 13:11:01 +0100 Subject: [PATCH 03/11] RISC-V: drop a needless check in print_isa_ext() isa_ext_arr cannot be empty, as some of the extensions within it are always built into the kernel. When this code was first added, back in commit a9b202606c69 ("RISC-V: Improve /proc/cpuinfo output for ISA extensions"), the array was empty and needed a dummy item & thus there could be no extensions present. When the first multi-letter ones did get added, it was Sscofpmf - which didn't have a Kconfig symbol to disable it. Remove this check, as it has been redundant since Sscofpmf was added. Reviewed-by: Andrew Jones Signed-off-by: Conor Dooley Link: https://lore.kernel.org/r/20230713-veggie-mug-3d3bf6787ae2@wendy Signed-off-by: Palmer Dabbelt --- arch/riscv/kernel/cpu.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c index f808b67f5a27..e721f15fdf17 100644 --- a/arch/riscv/kernel/cpu.c +++ b/arch/riscv/kernel/cpu.c @@ -237,10 +237,6 @@ static void print_isa_ext(struct seq_file *f) arr_sz = ARRAY_SIZE(isa_ext_arr) - 1; - /* No extension support available */ - if (arr_sz <= 0) - return; - for (i = 0; i <= arr_sz; i++) { edata = &isa_ext_arr[i]; if (!__riscv_isa_extension_available(NULL, edata->isa_ext_id)) From 8135ade32c0db48e2e75b039b2c2454f722762de Mon Sep 17 00:00:00 2001 From: Conor Dooley Date: Thu, 13 Jul 2023 13:11:02 +0100 Subject: [PATCH 04/11] RISC-V: shunt isa_ext_arr to cpufeature.c To facilitate using one struct to define extensions, rather than having several, shunt isa_ext_arr to cpufeature.c, where it will be used for probing extension presence also. As that scope of the array as widened, prefix it with riscv & drop the type from the variable name. Since the new array is const, print_isa() needs a wee bit of cleanup to avoid complaints about losing the const qualifier. Reviewed-by: Andrew Jones Reviewed-by: Evan Green Signed-off-by: Conor Dooley Link: https://lore.kernel.org/r/20230713-spirits-upside-a2c61c65fd5a@wendy Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/hwcap.h | 3 ++ arch/riscv/kernel/cpu.c | 75 +--------------------------------- arch/riscv/kernel/cpufeature.c | 67 ++++++++++++++++++++++++++++++ 3 files changed, 72 insertions(+), 73 deletions(-) diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h index f041bfa7f6a0..7a57e6109aef 100644 --- a/arch/riscv/include/asm/hwcap.h +++ b/arch/riscv/include/asm/hwcap.h @@ -76,6 +76,9 @@ struct riscv_isa_ext_data { unsigned int isa_ext_id; }; +extern const struct riscv_isa_ext_data riscv_isa_ext[]; +extern const size_t riscv_isa_ext_count; + unsigned long riscv_isa_extension_base(const unsigned long *isa_bitmap); #define riscv_isa_extension_mask(ext) BIT_MASK(RISCV_ISA_EXT_##ext) diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c index e721f15fdf17..bf93293d51f3 100644 --- a/arch/riscv/kernel/cpu.c +++ b/arch/riscv/kernel/cpu.c @@ -164,81 +164,10 @@ arch_initcall(riscv_cpuinfo_init); #ifdef CONFIG_PROC_FS -#define __RISCV_ISA_EXT_DATA(UPROP, EXTID) \ - { \ - .uprop = #UPROP, \ - .isa_ext_id = EXTID, \ - } - -/* - * 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. - */ -static struct riscv_isa_ext_data isa_ext_arr[] = { - __RISCV_ISA_EXT_DATA(zicbom, RISCV_ISA_EXT_ZICBOM), - __RISCV_ISA_EXT_DATA(zicboz, RISCV_ISA_EXT_ZICBOZ), - __RISCV_ISA_EXT_DATA(zicntr, RISCV_ISA_EXT_ZICNTR), - __RISCV_ISA_EXT_DATA(zicsr, RISCV_ISA_EXT_ZICSR), - __RISCV_ISA_EXT_DATA(zifencei, RISCV_ISA_EXT_ZIFENCEI), - __RISCV_ISA_EXT_DATA(zihintpause, RISCV_ISA_EXT_ZIHINTPAUSE), - __RISCV_ISA_EXT_DATA(zihpm, RISCV_ISA_EXT_ZIHPM), - __RISCV_ISA_EXT_DATA(zba, RISCV_ISA_EXT_ZBA), - __RISCV_ISA_EXT_DATA(zbb, RISCV_ISA_EXT_ZBB), - __RISCV_ISA_EXT_DATA(zbs, RISCV_ISA_EXT_ZBS), - __RISCV_ISA_EXT_DATA(smaia, RISCV_ISA_EXT_SMAIA), - __RISCV_ISA_EXT_DATA(ssaia, RISCV_ISA_EXT_SSAIA), - __RISCV_ISA_EXT_DATA(sscofpmf, RISCV_ISA_EXT_SSCOFPMF), - __RISCV_ISA_EXT_DATA(sstc, RISCV_ISA_EXT_SSTC), - __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("", RISCV_ISA_EXT_MAX), -}; - static void print_isa_ext(struct seq_file *f) { - struct riscv_isa_ext_data *edata; - int i = 0, arr_sz; - - arr_sz = ARRAY_SIZE(isa_ext_arr) - 1; - - for (i = 0; i <= arr_sz; i++) { - edata = &isa_ext_arr[i]; + for (int i = 0; i < riscv_isa_ext_count; i++) { + const struct riscv_isa_ext_data *edata = &riscv_isa_ext[i]; if (!__riscv_isa_extension_available(NULL, edata->isa_ext_id)) continue; seq_printf(f, "_%s", edata->uprop); diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c index bdcf460ea53d..fb476153fffc 100644 --- a/arch/riscv/kernel/cpufeature.c +++ b/arch/riscv/kernel/cpufeature.c @@ -99,6 +99,73 @@ static bool riscv_isa_extension_check(int id) return true; } +#define __RISCV_ISA_EXT_DATA(UPROP, EXTID) \ + { \ + .uprop = #UPROP, \ + .isa_ext_id = EXTID, \ + } + +/* + * 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(zicbom, RISCV_ISA_EXT_ZICBOM), + __RISCV_ISA_EXT_DATA(zicboz, RISCV_ISA_EXT_ZICBOZ), + __RISCV_ISA_EXT_DATA(zicntr, RISCV_ISA_EXT_ZICNTR), + __RISCV_ISA_EXT_DATA(zicsr, RISCV_ISA_EXT_ZICSR), + __RISCV_ISA_EXT_DATA(zifencei, RISCV_ISA_EXT_ZIFENCEI), + __RISCV_ISA_EXT_DATA(zihintpause, RISCV_ISA_EXT_ZIHINTPAUSE), + __RISCV_ISA_EXT_DATA(zihpm, RISCV_ISA_EXT_ZIHPM), + __RISCV_ISA_EXT_DATA(zba, RISCV_ISA_EXT_ZBA), + __RISCV_ISA_EXT_DATA(zbb, RISCV_ISA_EXT_ZBB), + __RISCV_ISA_EXT_DATA(zbs, RISCV_ISA_EXT_ZBS), + __RISCV_ISA_EXT_DATA(smaia, RISCV_ISA_EXT_SMAIA), + __RISCV_ISA_EXT_DATA(ssaia, RISCV_ISA_EXT_SSAIA), + __RISCV_ISA_EXT_DATA(sscofpmf, RISCV_ISA_EXT_SSCOFPMF), + __RISCV_ISA_EXT_DATA(sstc, RISCV_ISA_EXT_SSTC), + __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), +}; + +const size_t riscv_isa_ext_count = ARRAY_SIZE(riscv_isa_ext); + void __init riscv_fill_hwcap(void) { struct device_node *node; From 37f988dcec056532820fb7c3e9a8367fd19f6c1b Mon Sep 17 00:00:00 2001 From: Conor Dooley Date: Thu, 13 Jul 2023 13:11:03 +0100 Subject: [PATCH 05/11] RISC-V: repurpose riscv_isa_ext array in riscv_fill_hwcap() In riscv_fill_hwcap() riscv_isa_ext array can be looped over, rather than duplicating the list of extensions with individual SET_ISA_EXT_MAP() usage. While at it, drop the statement-of-the-obvious comments from the struct, rename uprop to something more suitable for its new use & constify the members. Reviewed-by: Andrew Jones Signed-off-by: Conor Dooley Link: https://lore.kernel.org/r/20230713-dastardly-affiliate-4cf819dccde2@wendy Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/hwcap.h | 7 ++----- arch/riscv/kernel/cpu.c | 5 +++-- arch/riscv/kernel/cpufeature.c | 30 +++++++++--------------------- 3 files changed, 14 insertions(+), 28 deletions(-) diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h index 7a57e6109aef..2460ac2fc7ed 100644 --- a/arch/riscv/include/asm/hwcap.h +++ b/arch/riscv/include/asm/hwcap.h @@ -55,7 +55,6 @@ #define RISCV_ISA_EXT_ZIHPM 42 #define RISCV_ISA_EXT_MAX 64 -#define RISCV_ISA_EXT_NAME_LEN_MAX 32 #ifdef CONFIG_RISCV_M_MODE #define RISCV_ISA_EXT_SxAIA RISCV_ISA_EXT_SMAIA @@ -70,10 +69,8 @@ unsigned long riscv_get_elf_hwcap(void); struct riscv_isa_ext_data { - /* Name of the extension displayed to userspace via /proc/cpuinfo */ - char uprop[RISCV_ISA_EXT_NAME_LEN_MAX]; - /* The logical ISA extension ID */ - unsigned int isa_ext_id; + const unsigned int id; + const char *name; }; extern const struct riscv_isa_ext_data riscv_isa_ext[]; diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c index bf93293d51f3..aa17eeb0ec9a 100644 --- a/arch/riscv/kernel/cpu.c +++ b/arch/riscv/kernel/cpu.c @@ -168,9 +168,10 @@ static void print_isa_ext(struct seq_file *f) { for (int i = 0; i < riscv_isa_ext_count; i++) { const struct riscv_isa_ext_data *edata = &riscv_isa_ext[i]; - if (!__riscv_isa_extension_available(NULL, edata->isa_ext_id)) + if (!__riscv_isa_extension_available(NULL, edata->id)) continue; - seq_printf(f, "_%s", edata->uprop); + + seq_printf(f, "_%s", edata->name); } } diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c index fb476153fffc..859e3831fac1 100644 --- a/arch/riscv/kernel/cpufeature.c +++ b/arch/riscv/kernel/cpufeature.c @@ -99,11 +99,10 @@ static bool riscv_isa_extension_check(int id) return true; } -#define __RISCV_ISA_EXT_DATA(UPROP, EXTID) \ - { \ - .uprop = #UPROP, \ - .isa_ext_id = EXTID, \ - } +#define __RISCV_ISA_EXT_DATA(_name, _id) { \ + .name = #_name, \ + .id = _id, \ +} /* * The canonical order of ISA extension names in the ISA string is defined in @@ -350,8 +349,8 @@ void __init riscv_fill_hwcap(void) #define SET_ISA_EXT_MAP(name, bit) \ do { \ - if ((ext_end - ext == sizeof(name) - 1) && \ - !strncasecmp(ext, name, sizeof(name) - 1) && \ + if ((ext_end - ext == strlen(name)) && \ + !strncasecmp(ext, name, strlen(name)) && \ riscv_isa_extension_check(bit)) \ set_bit(bit, isainfo->isa); \ } while (false) \ @@ -366,20 +365,9 @@ void __init riscv_fill_hwcap(void) set_bit(nr, isainfo->isa); } } else { - /* sorted alphabetically */ - SET_ISA_EXT_MAP("smaia", RISCV_ISA_EXT_SMAIA); - SET_ISA_EXT_MAP("ssaia", RISCV_ISA_EXT_SSAIA); - SET_ISA_EXT_MAP("sscofpmf", RISCV_ISA_EXT_SSCOFPMF); - SET_ISA_EXT_MAP("sstc", RISCV_ISA_EXT_SSTC); - SET_ISA_EXT_MAP("svinval", RISCV_ISA_EXT_SVINVAL); - SET_ISA_EXT_MAP("svnapot", RISCV_ISA_EXT_SVNAPOT); - SET_ISA_EXT_MAP("svpbmt", RISCV_ISA_EXT_SVPBMT); - SET_ISA_EXT_MAP("zba", RISCV_ISA_EXT_ZBA); - SET_ISA_EXT_MAP("zbb", RISCV_ISA_EXT_ZBB); - SET_ISA_EXT_MAP("zbs", RISCV_ISA_EXT_ZBS); - SET_ISA_EXT_MAP("zicbom", RISCV_ISA_EXT_ZICBOM); - SET_ISA_EXT_MAP("zicboz", RISCV_ISA_EXT_ZICBOZ); - SET_ISA_EXT_MAP("zihintpause", RISCV_ISA_EXT_ZIHINTPAUSE); + for (int i = 0; i < riscv_isa_ext_count; i++) + SET_ISA_EXT_MAP(riscv_isa_ext[i].name, + riscv_isa_ext[i].id); } #undef SET_ISA_EXT_MAP } From c30556e318cc3d8e04349aea6505639ec8a5fbdc Mon Sep 17 00:00:00 2001 From: Conor Dooley Date: Thu, 13 Jul 2023 13:11:04 +0100 Subject: [PATCH 06/11] RISC-V: add missing single letter extension definitions To facilitate adding single letter extensions to riscv_isa_ext, add definitions for the extensions present in base_riscv_exts that do not already have them. Reviewed-by: Andrew Jones Reviewed-by: Evan Green Signed-off-by: Conor Dooley Link: https://lore.kernel.org/r/20230713-train-feisty-93de38250f98@wendy Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/hwcap.h | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h index 2460ac2fc7ed..a20e4ade1b53 100644 --- a/arch/riscv/include/asm/hwcap.h +++ b/arch/riscv/include/asm/hwcap.h @@ -14,12 +14,17 @@ #include #define RISCV_ISA_EXT_a ('a' - 'a') +#define RISCV_ISA_EXT_b ('b' - 'a') #define RISCV_ISA_EXT_c ('c' - 'a') #define RISCV_ISA_EXT_d ('d' - 'a') #define RISCV_ISA_EXT_f ('f' - 'a') #define RISCV_ISA_EXT_h ('h' - 'a') #define RISCV_ISA_EXT_i ('i' - 'a') +#define RISCV_ISA_EXT_j ('j' - 'a') +#define RISCV_ISA_EXT_k ('k' - 'a') #define RISCV_ISA_EXT_m ('m' - 'a') +#define RISCV_ISA_EXT_p ('p' - 'a') +#define RISCV_ISA_EXT_q ('q' - 'a') #define RISCV_ISA_EXT_s ('s' - 'a') #define RISCV_ISA_EXT_u ('u' - 'a') #define RISCV_ISA_EXT_v ('v' - 'a') From effc122ad17698996ce2e839c69695cd22645be1 Mon Sep 17 00:00:00 2001 From: Conor Dooley Date: Thu, 13 Jul 2023 13:11:05 +0100 Subject: [PATCH 07/11] RISC-V: add single letter extensions to riscv_isa_ext So that riscv_fill_hwcap() can use riscv_isa_ext to probe for single letter extensions, add them to it. As a result, what gets spat out in /proc/cpuinfo will become borked, as single letter extensions will be printed as part of the base extensions and while printing from riscv_isa_arr. Take the opportunity to unify the printing of the isa string, using the new member of riscv_isa_ext_data in the process. Reviewed-by: Andrew Jones Signed-off-by: Conor Dooley Link: https://lore.kernel.org/r/20230713-despite-bright-de00ac888cc7@wendy Signed-off-by: Palmer Dabbelt --- arch/riscv/kernel/cpu.c | 37 ++++++++++------------------------ arch/riscv/kernel/cpufeature.c | 13 ++++++++++++ 2 files changed, 24 insertions(+), 26 deletions(-) diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c index aa17eeb0ec9a..4f1f12f34b63 100644 --- a/arch/riscv/kernel/cpu.c +++ b/arch/riscv/kernel/cpu.c @@ -164,41 +164,26 @@ arch_initcall(riscv_cpuinfo_init); #ifdef CONFIG_PROC_FS -static void print_isa_ext(struct seq_file *f) -{ - for (int i = 0; i < riscv_isa_ext_count; i++) { - const struct riscv_isa_ext_data *edata = &riscv_isa_ext[i]; - if (!__riscv_isa_extension_available(NULL, edata->id)) - continue; - - seq_printf(f, "_%s", edata->name); - } -} - -/* - * These are the only valid base (single letter) ISA extensions as per the spec. - * It also specifies the canonical order in which it appears in the spec. - * Some of the extension may just be a place holder for now (B, K, P, J). - * This should be updated once corresponding extensions are ratified. - */ -static const char base_riscv_exts[13] = "imafdqcbkjpvh"; - static void print_isa(struct seq_file *f) { - int i; - seq_puts(f, "isa\t\t: "); + if (IS_ENABLED(CONFIG_32BIT)) seq_write(f, "rv32", 4); else seq_write(f, "rv64", 4); - for (i = 0; i < sizeof(base_riscv_exts); i++) { - if (__riscv_isa_extension_available(NULL, base_riscv_exts[i] - 'a')) - /* Print only enabled the base ISA extensions */ - seq_write(f, &base_riscv_exts[i], 1); + for (int i = 0; i < riscv_isa_ext_count; i++) { + if (!__riscv_isa_extension_available(NULL, riscv_isa_ext[i].id)) + continue; + + /* Only multi-letter extensions are split by underscores */ + if (strnlen(riscv_isa_ext[i].name, 2) != 1) + seq_puts(f, "_"); + + seq_printf(f, "%s", riscv_isa_ext[i].name); } - print_isa_ext(f); + seq_puts(f, "\n"); } diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c index 859e3831fac1..d6009bd4c186 100644 --- a/arch/riscv/kernel/cpufeature.c +++ b/arch/riscv/kernel/cpufeature.c @@ -144,6 +144,19 @@ static bool riscv_isa_extension_check(int id) * 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_DATA(c, RISCV_ISA_EXT_c), + __RISCV_ISA_EXT_DATA(b, RISCV_ISA_EXT_b), + __RISCV_ISA_EXT_DATA(k, RISCV_ISA_EXT_k), + __RISCV_ISA_EXT_DATA(j, RISCV_ISA_EXT_j), + __RISCV_ISA_EXT_DATA(p, RISCV_ISA_EXT_p), + __RISCV_ISA_EXT_DATA(v, RISCV_ISA_EXT_v), + __RISCV_ISA_EXT_DATA(h, RISCV_ISA_EXT_h), __RISCV_ISA_EXT_DATA(zicbom, RISCV_ISA_EXT_ZICBOM), __RISCV_ISA_EXT_DATA(zicboz, RISCV_ISA_EXT_ZICBOZ), __RISCV_ISA_EXT_DATA(zicntr, RISCV_ISA_EXT_ZICNTR), From 4265b0ec5ee7bf64639cc088f378a51ca335b8a4 Mon Sep 17 00:00:00 2001 From: Conor Dooley Date: Thu, 13 Jul 2023 13:11:06 +0100 Subject: [PATCH 08/11] RISC-V: split riscv_fill_hwcap() in 3 Before adding more complexity to it, split riscv_fill_hwcap() into 3 distinct sections: - riscv_fill_hwcap() still is the top level function, into which the additional complexity will be added. - riscv_fill_hwcap_from_isa_string() handles getting the information from the riscv,isa/ACPI equivalent across harts & the various quirks there - riscv_parse_isa_string() does what it says on the tin. Reviewed-by: Andrew Jones Signed-off-by: Conor Dooley Link: https://lore.kernel.org/r/20230713-daylight-puritan-37aeb41a4d9b@wendy Signed-off-by: Palmer Dabbelt --- arch/riscv/kernel/cpufeature.c | 345 +++++++++++++++++---------------- 1 file changed, 177 insertions(+), 168 deletions(-) diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c index d6009bd4c186..7c661b12ac8d 100644 --- a/arch/riscv/kernel/cpufeature.c +++ b/arch/riscv/kernel/cpufeature.c @@ -178,29 +178,172 @@ const struct riscv_isa_ext_data riscv_isa_ext[] = { const size_t riscv_isa_ext_count = ARRAY_SIZE(riscv_isa_ext); -void __init riscv_fill_hwcap(void) +static void __init riscv_parse_isa_string(unsigned long *this_hwcap, struct riscv_isainfo *isainfo, + unsigned long *isa2hwcap, const char *isa) +{ + /* + * 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_long = false, ext_err = false; + + switch (*ext) { + 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 until multi-letter + * extension starting with "Su" appears. + */ + if (ext[-1] != '_' && ext[1] == 'u') { + ++isa; + ext_err = true; + break; + } + fallthrough; + case 'S': + case 'x': + case 'X': + 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. + */ + ext_long = true; + 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; + +#define SET_ISA_EXT_MAP(name, bit) \ + do { \ + if ((ext_end - ext == strlen(name)) && \ + !strncasecmp(ext, name, strlen(name)) && \ + riscv_isa_extension_check(bit)) \ + set_bit(bit, isainfo->isa); \ + } while (false) \ + + if (unlikely(ext_err)) + continue; + if (!ext_long) { + int nr = tolower(*ext) - 'a'; + + if (riscv_isa_extension_check(nr)) { + *this_hwcap |= isa2hwcap[nr]; + set_bit(nr, isainfo->isa); + } + } else { + for (int i = 0; i < riscv_isa_ext_count; i++) + SET_ISA_EXT_MAP(riscv_isa_ext[i].name, + riscv_isa_ext[i].id); + } +#undef SET_ISA_EXT_MAP + } +} + +static void __init riscv_fill_hwcap_from_isa_string(unsigned long *isa2hwcap) { struct device_node *node; const char *isa; - char print_str[NUM_ALPHA_EXTS + 1]; - int i, j, rc; - unsigned long isa2hwcap[26] = {0}; + int rc; struct acpi_table_header *rhct; acpi_status status; unsigned int cpu; - 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; - - elf_hwcap = 0; - - bitmap_zero(riscv_isa, RISCV_ISA_EXT_MAX); - if (!acpi_disabled) { status = acpi_get_table(ACPI_SIG_RHCT, 0, &rhct); if (ACPI_FAILURE(status)) @@ -232,158 +375,7 @@ void __init riscv_fill_hwcap(void) } } - /* - * 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_long = false, ext_err = false; - - switch (*ext) { - 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 until multi-letter - * extension starting with "Su" appears. - */ - if (ext[-1] != '_' && ext[1] == 'u') { - ++isa; - ext_err = true; - break; - } - fallthrough; - case 'S': - case 'x': - case 'X': - 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. - */ - ext_long = true; - 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; - -#define SET_ISA_EXT_MAP(name, bit) \ - do { \ - if ((ext_end - ext == strlen(name)) && \ - !strncasecmp(ext, name, strlen(name)) && \ - riscv_isa_extension_check(bit)) \ - set_bit(bit, isainfo->isa); \ - } while (false) \ - - if (unlikely(ext_err)) - continue; - if (!ext_long) { - int nr = tolower(*ext) - 'a'; - - if (riscv_isa_extension_check(nr)) { - this_hwcap |= isa2hwcap[nr]; - set_bit(nr, isainfo->isa); - } - } else { - for (int i = 0; i < riscv_isa_ext_count; i++) - SET_ISA_EXT_MAP(riscv_isa_ext[i].name, - riscv_isa_ext[i].id); - } -#undef SET_ISA_EXT_MAP - } + riscv_parse_isa_string(&this_hwcap, isainfo, isa2hwcap, isa); /* * Linux requires the following extensions, so we may as well @@ -420,6 +412,23 @@ void __init riscv_fill_hwcap(void) if (!acpi_disabled && rhct) acpi_put_table((struct acpi_table_header *)rhct); +} + +void __init riscv_fill_hwcap(void) +{ + char print_str[NUM_ALPHA_EXTS + 1]; + int i, j; + unsigned long isa2hwcap[26] = {0}; + + 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; + + riscv_fill_hwcap_from_isa_string(isa2hwcap); /* We don't support systems with F but without D, so mask those out * here. */ From 90700a4fbfaf30bc792b72ddda5666a19ddd6c6a Mon Sep 17 00:00:00 2001 From: Conor Dooley Date: Thu, 13 Jul 2023 13:11:07 +0100 Subject: [PATCH 09/11] RISC-V: enable extension detection from dedicated properties Add support for parsing the new riscv,isa-extensions property in riscv_fill_hwcap(), by means of a new "property" member of the riscv_isa_ext_data struct. For now, this shadows the name of the extension for all users, however this may not be the case for all extensions, based on how the dt-binding is written. For the sake of backwards compatibility, fall back to the old scheme if the new properties are not detected. For now, just inform, rather than warn, when that happens. Reviewed-by: Andrew Jones Signed-off-by: Conor Dooley Link: https://lore.kernel.org/r/20230713-vocation-profane-39a74b3c2649@wendy Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/hwcap.h | 1 + arch/riscv/kernel/cpufeature.c | 78 ++++++++++++++++++++++++++++++++-- 2 files changed, 75 insertions(+), 4 deletions(-) diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h index a20e4ade1b53..e3cda14a486b 100644 --- a/arch/riscv/include/asm/hwcap.h +++ b/arch/riscv/include/asm/hwcap.h @@ -76,6 +76,7 @@ unsigned long riscv_get_elf_hwcap(void); struct riscv_isa_ext_data { const unsigned int id; const char *name; + const char *property; }; extern const struct riscv_isa_ext_data riscv_isa_ext[]; diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c index 7c661b12ac8d..fdc71e52dc2b 100644 --- a/arch/riscv/kernel/cpufeature.c +++ b/arch/riscv/kernel/cpufeature.c @@ -101,6 +101,7 @@ static bool riscv_isa_extension_check(int id) #define __RISCV_ISA_EXT_DATA(_name, _id) { \ .name = #_name, \ + .property = #_name, \ .id = _id, \ } @@ -414,11 +415,69 @@ static void __init riscv_fill_hwcap_from_isa_string(unsigned long *isa2hwcap) acpi_put_table((struct acpi_table_header *)rhct); } +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]; + + 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++) { + if (of_property_match_string(cpu_node, "riscv,isa-extensions", + riscv_isa_ext[i].property) < 0) + continue; + + if (!riscv_isa_extension_check(riscv_isa_ext[i].id)) + continue; + + /* Only single letter extensions get set in hwcap */ + if (strnlen(riscv_isa_ext[i].name, 2) == 1) + this_hwcap |= isa2hwcap[riscv_isa_ext[i].id]; + + set_bit(riscv_isa_ext[i].id, isainfo->isa); + } + + 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); + } + + if (bitmap_empty(riscv_isa, RISCV_ISA_EXT_MAX)) + return -ENOENT; + + return 0; +} + void __init riscv_fill_hwcap(void) { char print_str[NUM_ALPHA_EXTS + 1]; - int i, j; unsigned long isa2hwcap[26] = {0}; + int i, j; isa2hwcap['i' - 'a'] = COMPAT_HWCAP_ISA_I; isa2hwcap['m' - 'a'] = COMPAT_HWCAP_ISA_M; @@ -428,10 +487,21 @@ void __init riscv_fill_hwcap(void) isa2hwcap['c' - 'a'] = COMPAT_HWCAP_ISA_C; isa2hwcap['v' - 'a'] = COMPAT_HWCAP_ISA_V; - riscv_fill_hwcap_from_isa_string(isa2hwcap); + if (!acpi_disabled) { + riscv_fill_hwcap_from_isa_string(isa2hwcap); + } else { + int ret = riscv_fill_hwcap_from_ext_list(isa2hwcap); - /* We don't support systems with F but without D, so mask those out - * here. */ + if (ret) { + 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; From c98f136aedbd4384311b06db4ec9d2fd1996cffc Mon Sep 17 00:00:00 2001 From: Conor Dooley Date: Thu, 13 Jul 2023 13:11:08 +0100 Subject: [PATCH 10/11] RISC-V: try new extension properties in of_early_processor_hartid() To fully deprecate the kernel's use of "riscv,isa", of_early_processor_hartid() needs to first try using the new properties, before falling back to "riscv,isa". Reviewed-by: Andrew Jones Signed-off-by: Conor Dooley Link: https://lore.kernel.org/r/20230713-tablet-jimmy-987fea0eb2e1@wendy Signed-off-by: Palmer Dabbelt --- arch/riscv/kernel/cpu.c | 29 ++++++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-) diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c index 4f1f12f34b63..28d5af21f544 100644 --- a/arch/riscv/kernel/cpu.c +++ b/arch/riscv/kernel/cpu.c @@ -61,8 +61,35 @@ int riscv_early_of_processor_hartid(struct device_node *node, unsigned long *har return -ENODEV; } + if (of_property_read_string(node, "riscv,isa-base", &isa)) + goto old_interface; + + if (IS_ENABLED(CONFIG_32BIT) && strncasecmp(isa, "rv32i", 5)) { + pr_warn("CPU with hartid=%lu does not support rv32i", *hart); + return -ENODEV; + } + + if (IS_ENABLED(CONFIG_64BIT) && strncasecmp(isa, "rv64i", 5)) { + pr_warn("CPU with hartid=%lu does not support rv64i", *hart); + return -ENODEV; + } + + if (!of_property_present(node, "riscv,isa-extensions")) + return -ENODEV; + + if (of_property_match_string(node, "riscv,isa-extensions", "i") < 0 || + of_property_match_string(node, "riscv,isa-extensions", "m") < 0 || + of_property_match_string(node, "riscv,isa-extensions", "a") < 0) { + pr_warn("CPU with hartid=%lu does not support ima", *hart); + return -ENODEV; + } + + return 0; + +old_interface: if (of_property_read_string(node, "riscv,isa", &isa)) { - pr_warn("CPU with hartid=%lu has no \"riscv,isa\" property\n", *hart); + pr_warn("CPU with hartid=%lu has no \"riscv,isa-base\" or \"riscv,isa\" property\n", + *hart); return -ENODEV; } From 496ea826d1e1f9744e2a4c36043db933deebab43 Mon Sep 17 00:00:00 2001 From: Conor Dooley Date: Thu, 13 Jul 2023 13:11:09 +0100 Subject: [PATCH 11/11] RISC-V: provide Kconfig & commandline options to control parsing "riscv,isa" As it says on the tin, provide Kconfig option to control parsing the "riscv,isa" devicetree property. If either option is used, the kernel will fall back to parsing "riscv,isa", where "riscv,isa-base" and "riscv,isa-extensions" are not present. The Kconfig options are set up so that the default kernel configuration will enable the fallback path, without needing the commandline option. Suggested-by: Andrew Jones Suggested-by: Palmer Dabbelt Reviewed-by: Andrew Jones Signed-off-by: Conor Dooley Link: https://lore.kernel.org/r/20230713-aviator-plausibly-a35662485c2c@wendy Signed-off-by: Palmer Dabbelt --- .../admin-guide/kernel-parameters.txt | 7 +++++++ arch/riscv/Kconfig | 18 ++++++++++++++++++ arch/riscv/include/asm/hwcap.h | 1 + arch/riscv/kernel/cpu.c | 8 +++++++- arch/riscv/kernel/cpufeature.c | 14 +++++++++++++- 5 files changed, 46 insertions(+), 2 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index a1457995fd41..bdc3fa712e92 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -5468,6 +5468,13 @@ [KNL] Disable ring 3 MONITOR/MWAIT feature on supported CPUs. + riscv_isa_fallback [RISCV] + When CONFIG_RISCV_ISA_FALLBACK is not enabled, permit + falling back to detecting extension support by parsing + "riscv,isa" property on devicetree systems when the + replacement properties are not found. See the Kconfig + entry for RISCV_ISA_FALLBACK. + ro [KNL] Mount root device read-only on boot rodata= [KNL] diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 4c07b9189c86..f52dd125ac5e 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -848,6 +848,24 @@ config XIP_PHYS_ADDR be linked for and stored to. This address is dependent on your own flash usage. +config RISCV_ISA_FALLBACK + bool "Permit falling back to parsing riscv,isa for extension support by default" + default y + help + Parsing the "riscv,isa" devicetree property has been deprecated and + replaced by a list of explicitly defined strings. For compatibility + with existing platforms, the kernel will fall back to parsing the + "riscv,isa" property if the replacements are not found. + + Selecting N here will result in a kernel that does not use the + fallback, unless the commandline "riscv_isa_fallback" parameter is + present. + + Please see the dt-binding, located at + Documentation/devicetree/bindings/riscv/extensions.yaml for details + on the replacement properties, "riscv,isa-base" and + "riscv,isa-extensions". + endmenu # "Boot options" config BUILTIN_DTB diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h index e3cda14a486b..b7b58258f6c7 100644 --- a/arch/riscv/include/asm/hwcap.h +++ b/arch/riscv/include/asm/hwcap.h @@ -81,6 +81,7 @@ struct riscv_isa_ext_data { extern const struct riscv_isa_ext_data riscv_isa_ext[]; extern const size_t riscv_isa_ext_count; +extern bool riscv_isa_fallback; unsigned long riscv_isa_extension_base(const unsigned long *isa_bitmap); diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c index 28d5af21f544..208f1a700121 100644 --- a/arch/riscv/kernel/cpu.c +++ b/arch/riscv/kernel/cpu.c @@ -41,7 +41,7 @@ int riscv_of_processor_hartid(struct device_node *node, unsigned long *hart) return 0; } -int riscv_early_of_processor_hartid(struct device_node *node, unsigned long *hart) +int __init riscv_early_of_processor_hartid(struct device_node *node, unsigned long *hart) { const char *isa; @@ -87,6 +87,12 @@ int riscv_early_of_processor_hartid(struct device_node *node, unsigned long *har return 0; old_interface: + if (!riscv_isa_fallback) { + pr_warn("CPU with hartid=%lu is invalid: this kernel does not parse \"riscv,isa\"", + *hart); + return -ENODEV; + } + if (of_property_read_string(node, "riscv,isa", &isa)) { pr_warn("CPU with hartid=%lu has no \"riscv,isa-base\" or \"riscv,isa\" property\n", *hart); diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c index fdc71e52dc2b..71fb840ee246 100644 --- a/arch/riscv/kernel/cpufeature.c +++ b/arch/riscv/kernel/cpufeature.c @@ -473,6 +473,18 @@ static int __init riscv_fill_hwcap_from_ext_list(unsigned long *isa2hwcap) 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]; @@ -492,7 +504,7 @@ void __init riscv_fill_hwcap(void) } else { int ret = riscv_fill_hwcap_from_ext_list(isa2hwcap); - if (ret) { + if (ret && riscv_isa_fallback) { pr_info("Falling back to deprecated \"riscv,isa\"\n"); riscv_fill_hwcap_from_isa_string(isa2hwcap); }