Hi Bin,
On Tue, 2018-12-11 at 23:11 -0800, Bin Meng wrote:
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.cn@gmail.com
Changes in v4:
- print warnings for S-mode without CONFIG_CPU
Changes in v3:
- new patch to update supports_extension() to use desc from cpu
driver
Changes in v2: None
arch/riscv/cpu/cpu.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+)
diff --git a/arch/riscv/cpu/cpu.c b/arch/riscv/cpu/cpu.c index d3c59da..a2ebaf3 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 +18,27 @@ 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);
Sorry, I missed this before. Can you add error handling here to catch uclass_find_first_device returning an error or not finding a device? It would probably also make sense to print a warning message to the user in this case.
Other than that, this patch and the series look good! Reviewed-by: Lukas Auer lukas.auer@aisec.fraunhofer.de
Thanks, Lukas
- 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 /* !CONFIG_CPU */ +#ifdef CONFIG_RISCV_MMODE return csr_read(misa) & (1 << (ext - 'a')); +#else /* !CONFIG_RISCV_MMODE */ +#warning "There is no way to determine the available extensions in S-mode." +#warning "Please convert your board to use the RISC-V CPU driver."
- return false;
+#endif /* CONFIG_RISCV_MMODE */ +#endif /* CONFIG_CPU */ }
static int riscv_cpu_probe(void)