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Diffstat (limited to 'arch/riscv/kernel/cpufeature.c')
-rw-r--r--arch/riscv/kernel/cpufeature.c31
1 files changed, 28 insertions, 3 deletions
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index 89920f84d0a3..79a5a35fab96 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -24,6 +24,7 @@
#include <asm/hwprobe.h>
#include <asm/patch.h>
#include <asm/processor.h>
+#include <asm/sbi.h>
#include <asm/vector.h>
#include "copy-unaligned.h"
@@ -202,6 +203,16 @@ static const unsigned int riscv_zvbb_exts[] = {
};
/*
+ * While the [ms]envcfg CSRs were not defined until version 1.12 of the RISC-V
+ * privileged ISA, the existence of the CSRs is implied by any extension which
+ * specifies [ms]envcfg bit(s). Hence, we define a custom ISA extension for the
+ * existence of the CSR, and treat it as a subset of those other extensions.
+ */
+static const unsigned int riscv_xlinuxenvcfg_exts[] = {
+ RISCV_ISA_EXT_XLINUXENVCFG
+};
+
+/*
* The canonical order of ISA extension names in the ISA string is defined in
* chapter 27 of the unprivileged specification.
*
@@ -250,8 +261,8 @@ const struct riscv_isa_ext_data riscv_isa_ext[] = {
__RISCV_ISA_EXT_DATA(c, RISCV_ISA_EXT_c),
__RISCV_ISA_EXT_DATA(v, RISCV_ISA_EXT_v),
__RISCV_ISA_EXT_DATA(h, RISCV_ISA_EXT_h),
- __RISCV_ISA_EXT_DATA(zicbom, RISCV_ISA_EXT_ZICBOM),
- __RISCV_ISA_EXT_DATA(zicboz, RISCV_ISA_EXT_ZICBOZ),
+ __RISCV_ISA_EXT_SUPERSET(zicbom, RISCV_ISA_EXT_ZICBOM, riscv_xlinuxenvcfg_exts),
+ __RISCV_ISA_EXT_SUPERSET(zicboz, RISCV_ISA_EXT_ZICBOZ, riscv_xlinuxenvcfg_exts),
__RISCV_ISA_EXT_DATA(zicntr, RISCV_ISA_EXT_ZICNTR),
__RISCV_ISA_EXT_DATA(zicond, RISCV_ISA_EXT_ZICOND),
__RISCV_ISA_EXT_DATA(zicsr, RISCV_ISA_EXT_ZICSR),
@@ -539,6 +550,20 @@ 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.
@@ -950,7 +975,7 @@ 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