[PATCH 1/3] riscv: Drop CONFIG_RISCV_ISA_V_DEFAULT_ENABLE

[Samuel Holland]

The ability to prevent userspace from executing vector instructions was
provided as a escape hatch for software that was broken by adding vector
state to the signal context. This appears to be unused in practice, and
creates confusion in the extension support returned by hwprobe(), as in
this one special case an extension reported as present by hwprobe() is
unusable.

Since we believe it is safe to always allow vector usage, start removing
this functionality by dropping the Kconfig option. It is possible to get
equivalent behavior by setting the sysctl at boot via the kernel command
line, but that method will also soon be deprecated.

Signed-off-by: Samuel Holland <samuel.holland@xxxxxxxxxx>
---

 arch/riscv/Kconfig         | 11 -----------
 arch/riscv/kernel/vector.c |  2 +-
 2 files changed, 1 insertion(+), 12 deletions(-)

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index d6c2dbf8455ce..e26450f0d38fb 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -650,17 +650,6 @@ config RISCV_ISA_V
 
 	  If you don't know what to do here, say Y.
 
-config RISCV_ISA_V_DEFAULT_ENABLE
-	bool "Enable userspace Vector by default"
-	depends on RISCV_ISA_V
-	default y
-	help
-	  Say Y here if you want to enable Vector in userspace by default.
-	  Otherwise, userspace has to make explicit prctl() call to enable
-	  Vector, or enable it via the sysctl interface.
-
-	  If you don't know what to do here, say Y.
-
 config RISCV_ISA_V_UCOPY_THRESHOLD
 	int "Threshold size for vectorized user copies"
 	depends on RISCV_ISA_V
diff --git a/arch/riscv/kernel/vector.c b/arch/riscv/kernel/vector.c
index b112166d51e9f..9641343732782 100644
--- a/arch/riscv/kernel/vector.c
+++ b/arch/riscv/kernel/vector.c
@@ -20,7 +20,7 @@
 #include <asm/ptrace.h>
 #include <asm/bug.h>
 
-static bool riscv_v_implicit_uacc = IS_ENABLED(CONFIG_RISCV_ISA_V_DEFAULT_ENABLE);
+static bool riscv_v_implicit_uacc = true;
 static struct kmem_cache *riscv_v_user_cachep;
 #ifdef CONFIG_RISCV_ISA_V_PREEMPTIVE
 static struct kmem_cache *riscv_v_kernel_cachep;
-- 
2.52.0