From d72f5f17478dfef3df817339a0f02cfdb77a1dc1 Mon Sep 17 00:00:00 2001 From: Himanshu Chauhan Date: Wed, 12 Jul 2023 10:04:31 +0530 Subject: [PATCH] lib: utils: Add detection of Smepmp from ISA string in FDT - Add function to parse ISA string in FDT. - Set Smepmp feature bit in extensions if "smepmp" string is found in ISA string. Signed-off-by: Himanshu Chauhan Reviewed-by: Anup Patel --- include/sbi_utils/fdt/fdt_helper.h | 3 + lib/utils/fdt/fdt_helper.c | 111 +++++++++++++++++++++++++++++ platform/generic/platform.c | 9 +++ 3 files changed, 123 insertions(+) diff --git a/include/sbi_utils/fdt/fdt_helper.h b/include/sbi_utils/fdt/fdt_helper.h index 39d7f3a..5c928ff 100644 --- a/include/sbi_utils/fdt/fdt_helper.h +++ b/include/sbi_utils/fdt/fdt_helper.h @@ -56,6 +56,9 @@ int fdt_parse_max_enabled_hart_id(void *fdt, u32 *max_hartid); int fdt_parse_timebase_frequency(void *fdt, unsigned long *freq); +int fdt_parse_isa_extensions(void *fdt, unsigned int hard_id, + unsigned long *extensions); + int fdt_parse_gaisler_uart_node(void *fdt, int nodeoffset, struct platform_uart_data *uart); diff --git a/lib/utils/fdt/fdt_helper.c b/lib/utils/fdt/fdt_helper.c index a88a4ba..61a4100 100644 --- a/lib/utils/fdt/fdt_helper.c +++ b/lib/utils/fdt/fdt_helper.c @@ -12,6 +12,7 @@ #include #include #include +#include #include #include #include @@ -313,6 +314,116 @@ int fdt_parse_timebase_frequency(void *fdt, unsigned long *freq) return 0; } +static int fdt_get_isa_string(void *fdt, unsigned int hartid, + const char **isa_string) +{ + int err, cpu_offset, cpus_offset, len; + u32 c_hartid; + const fdt32_t *val; + + if (!fdt) + return SBI_EINVAL; + + cpus_offset = fdt_path_offset(fdt, "/cpus"); + if (cpus_offset < 0) + return cpus_offset; + + fdt_for_each_subnode(cpu_offset, fdt, cpus_offset) { + err = fdt_parse_hart_id(fdt, cpu_offset, &c_hartid); + if (err) + continue; + + if (!fdt_node_is_enabled(fdt, cpu_offset)) + continue; + + if (c_hartid == hartid) { + val = fdt_getprop(fdt, cpu_offset, "riscv,isa", &len); + if (val && len > 0) { + *isa_string = (const char *)val; + return 0; + } + } + } + + return SBI_EINVAL; +} + +#define RISCV_ISA_EXT_NAME_LEN_MAX 32 + +int fdt_parse_isa_extensions(void *fdt, unsigned int hartid, + unsigned long *extensions) +{ + size_t i, j, isa_len; + char mstr[RISCV_ISA_EXT_NAME_LEN_MAX]; + const char *isa = NULL; + + if (fdt_get_isa_string(fdt, hartid, &isa)) + return SBI_EINVAL; + + if (!isa) + return SBI_EINVAL; + + i = 0; + isa_len = strlen(isa); + + if (isa[i] == 'r' || isa[i] == 'R') + i++; + else + return SBI_EINVAL; + + if (isa[i] == 'v' || isa[i] == 'V') + i++; + else + return SBI_EINVAL; + + if (isa[i] == '3' || isa[i+1] == '2') + i += 2; + else if (isa[i] == '6' || isa[i+1] == '4') + i += 2; + else + return SBI_EINVAL; + + /* Skip base ISA extensions */ + for (; i < isa_len; i++) { + if (isa[i] == '_') + break; + } + + while (i < isa_len) { + if (isa[i] != '_') { + i++; + continue; + } + + /* Skip the '_' character */ + i++; + + /* Extract the multi-letter extension name */ + j = 0; + while ((i < isa_len) && (isa[i] != '_') && + (j < (sizeof(mstr) - 1))) + mstr[j++] = isa[i++]; + mstr[j] = '\0'; + + /* Skip empty multi-letter extension name */ + if (!j) + continue; + +#define SET_ISA_EXT_MAP(name, bit) \ + do { \ + if (!strcmp(mstr, name)) { \ + __set_bit(bit, extensions); \ + continue; \ + } \ + } while (false) \ + + SET_ISA_EXT_MAP("smepmp", SBI_HART_EXT_SMEPMP); +#undef SET_ISA_EXT_MAP + } + + return 0; +} + static int fdt_parse_uart_node_common(void *fdt, int nodeoffset, struct platform_uart_data *uart, unsigned long default_freq, diff --git a/platform/generic/platform.c b/platform/generic/platform.c index 86811e6..34b87f7 100644 --- a/platform/generic/platform.c +++ b/platform/generic/platform.c @@ -211,6 +211,15 @@ static void generic_final_exit(void) static int generic_extensions_init(struct sbi_hart_features *hfeatures) { + int rc; + + /* Parse the ISA string from FDT and enable the listed extensions */ + rc = fdt_parse_isa_extensions(fdt_get_address(), current_hartid(), + &hfeatures->extensions); + + if (rc) + return rc; + if (generic_plat && generic_plat->extensions_init) return generic_plat->extensions_init(generic_plat_match, hfeatures);