[PATCH v2 3/3] xen/riscv: disable fpu

[Oleksii Kurochko <oleksii.kurochko@gmail.com>]

Disable FPU to detect illegal usage of floating point in kernel
space.

Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
---
Changes since v1:
 * Rebase on top of two previous patches.
---
 xen/arch/riscv/setup.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/xen/arch/riscv/setup.c b/xen/arch/riscv/setup.c
index d9723fe1c0..23d60ed7f0 100644
--- a/xen/arch/riscv/setup.c
+++ b/xen/arch/riscv/setup.c
@@ -1,15 +1,23 @@
 #include <xen/compile.h>
 #include <xen/init.h>
 
+#include <asm/csr.h>
 #include <asm/early_printk.h>
 
 /* Xen stack for bringing up the first CPU. */
 unsigned char __initdata cpu0_boot_stack[STACK_SIZE]
     __aligned(STACK_SIZE);
 
+static void __init disable_fpu(void)
+{
+    csr_write(CSR_SSTATUS, SSTATUS_FS);
+}
+
 void __init noreturn start_xen(unsigned long bootcpu_id,
                                unsigned long dtb_base)
 {
+    disable_fpu();
+
     early_printk("Hello from C env\n");
 
     early_printk("All set up\n");
-- 
2.39.0