This updates supports_extension() implementation to use the desc string from the cpu driver whenever possible, which avoids the reading of misa CSR for S-mode U-Boot.
Signed-off-by: Bin Meng <bmeng...@gmail.com> --- Changes in v3: - new patch to update supports_extension() to use desc from cpu driver Changes in v2: None arch/riscv/cpu/cpu.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/arch/riscv/cpu/cpu.c b/arch/riscv/cpu/cpu.c index d3c59da..704ae70 100644 --- a/arch/riscv/cpu/cpu.c +++ b/arch/riscv/cpu/cpu.c @@ -5,8 +5,10 @@ #include <common.h> #include <cpu.h> +#include <dm.h> #include <log.h> #include <asm/csr.h> +#include <dm/uclass-internal.h> /* * prior_stage_fdt_address must be stored in the data section since it is used @@ -16,7 +18,21 @@ phys_addr_t prior_stage_fdt_address __attribute__((section(".data"))); static inline bool supports_extension(char ext) { +#ifdef CONFIG_CPU + struct udevice *dev; + char desc[32]; + + uclass_find_first_device(UCLASS_CPU, &dev); + if (!cpu_get_desc(dev, desc, sizeof(desc))) { + /* skip the first 4 characters (rv32|rv64) */ + if (strchr(desc + 4, ext)) + return true; + } + + return false; +#else return csr_read(misa) & (1 << (ext - 'a')); +#endif } static int riscv_cpu_probe(void) -- 2.7.4 _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot