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-rw-r--r--arch/riscv/kernel/cpufeature.c17
1 files changed, 16 insertions, 1 deletions
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index b3785ffc15..8677788133 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -22,6 +22,7 @@
#include <asm/hwprobe.h>
#include <asm/patch.h>
#include <asm/processor.h>
+#include <asm/sbi.h>
#include <asm/vector.h>
#include "copy-unaligned.h"
@@ -402,6 +403,20 @@ static void __init riscv_fill_hwcap_from_isa_string(unsigned long *isa2hwcap)
}
/*
+ * "V" in ISA strings is ambiguous in practice: it should mean
+ * just the standard V-1.0 but vendors aren't well behaved.
+ * Many vendors with T-Head CPU cores which implement the 0.7.1
+ * version of the vector specification put "v" into their DTs.
+ * CPU cores with the ratified spec will contain non-zero
+ * marchid.
+ */
+ if (acpi_disabled && riscv_cached_mvendorid(cpu) == THEAD_VENDOR_ID &&
+ riscv_cached_marchid(cpu) == 0x0) {
+ this_hwcap &= ~isa2hwcap[RISCV_ISA_EXT_v];
+ clear_bit(RISCV_ISA_EXT_v, isainfo->isa);
+ }
+
+ /*
* All "okay" hart should have same isa. Set HWCAP based on
* common capabilities of every "okay" hart, in case they don't
* have.
@@ -725,7 +740,7 @@ arch_initcall(check_unaligned_access_all_cpus);
void riscv_user_isa_enable(void)
{
if (riscv_cpu_has_extension_unlikely(smp_processor_id(), RISCV_ISA_EXT_ZICBOZ))
- csr_set(CSR_SENVCFG, ENVCFG_CBZE);
+ csr_set(CSR_ENVCFG, ENVCFG_CBZE);
}
#ifdef CONFIG_RISCV_ALTERNATIVE