[PATCH v12 8/8] riscv: cpu: fu740: clear feature disable CSR
Green Wan
green.wan at sifive.com
Thu May 27 15:52:14 CEST 2021
Clear feature disable CSR to turn on all features of hart. The detail
is specified at section, 'SiFive Feature Disable CSR', in user manual
https://sifive.cdn.prismic.io/sifive/aee0dd4c-d156-496e-a6c4-db0cf54bbe68_sifive_U74MC_rtl_full_20G1.03.00_manual.pdf
Signed-off-by: Green Wan <green.wan at sifive.com>
Reviewed-by: Sean Anderson <seanga2 at gmail.com>
Reviewed-by: Bin Meng <bmeng.cn at gmail.com>
Reviewed-by: Rick Chen <rick at andestech.com>
---
arch/riscv/cpu/fu740/spl.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)
diff --git a/arch/riscv/cpu/fu740/spl.c b/arch/riscv/cpu/fu740/spl.c
index ea0b2283a2..55e30346ff 100644
--- a/arch/riscv/cpu/fu740/spl.c
+++ b/arch/riscv/cpu/fu740/spl.c
@@ -6,6 +6,9 @@
#include <dm.h>
#include <log.h>
+#include <asm/csr.h>
+
+#define CSR_U74_FEATURE_DISABLE 0x7c1
int spl_soc_init(void)
{
@@ -21,3 +24,15 @@ int spl_soc_init(void)
return 0;
}
+
+void harts_early_init(void)
+{
+ /*
+ * Feature Disable CSR
+ *
+ * Clear feature disable CSR to '0' to turn on all features for
+ * each core. This operation must be in M-mode.
+ */
+ if (CONFIG_IS_ENABLED(RISCV_MMODE))
+ csr_write(CSR_U74_FEATURE_DISABLE, 0);
+}
--
2.31.0
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