summaryrefslogtreecommitdiffstats
path: root/arch/riscv/kernel
diff options
context:
space:
mode:
Diffstat (limited to 'arch/riscv/kernel')
-rw-r--r--arch/riscv/kernel/Makefile2
-rw-r--r--arch/riscv/kernel/cpufeature.c17
-rw-r--r--arch/riscv/kernel/return_address.c48
3 files changed, 66 insertions, 1 deletions
diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
index fee22a3d1b..40d054939a 100644
--- a/arch/riscv/kernel/Makefile
+++ b/arch/riscv/kernel/Makefile
@@ -7,6 +7,7 @@ ifdef CONFIG_FTRACE
CFLAGS_REMOVE_ftrace.o = $(CC_FLAGS_FTRACE)
CFLAGS_REMOVE_patch.o = $(CC_FLAGS_FTRACE)
CFLAGS_REMOVE_sbi.o = $(CC_FLAGS_FTRACE)
+CFLAGS_REMOVE_return_address.o = $(CC_FLAGS_FTRACE)
endif
CFLAGS_syscall_table.o += $(call cc-option,-Wno-override-init,)
CFLAGS_compat_syscall_table.o += $(call cc-option,-Wno-override-init,)
@@ -46,6 +47,7 @@ obj-y += irq.o
obj-y += process.o
obj-y += ptrace.o
obj-y += reset.o
+obj-y += return_address.o
obj-y += setup.o
obj-y += signal.o
obj-y += syscall_table.o
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
diff --git a/arch/riscv/kernel/return_address.c b/arch/riscv/kernel/return_address.c
new file mode 100644
index 0000000000..c8115ec8fb
--- /dev/null
+++ b/arch/riscv/kernel/return_address.c
@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * This code come from arch/arm64/kernel/return_address.c
+ *
+ * Copyright (C) 2023 SiFive.
+ */
+
+#include <linux/export.h>
+#include <linux/kprobes.h>
+#include <linux/stacktrace.h>
+
+struct return_address_data {
+ unsigned int level;
+ void *addr;
+};
+
+static bool save_return_addr(void *d, unsigned long pc)
+{
+ struct return_address_data *data = d;
+
+ if (!data->level) {
+ data->addr = (void *)pc;
+ return false;
+ }
+
+ --data->level;
+
+ return true;
+}
+NOKPROBE_SYMBOL(save_return_addr);
+
+noinline void *return_address(unsigned int level)
+{
+ struct return_address_data data;
+
+ data.level = level + 3;
+ data.addr = NULL;
+
+ arch_stack_walk(save_return_addr, &data, current, NULL);
+
+ if (!data.level)
+ return data.addr;
+ else
+ return NULL;
+
+}
+EXPORT_SYMBOL_GPL(return_address);
+NOKPROBE_SYMBOL(return_address);