arm64/sve: Make sysctl interface for SVE reusable by SME

The vector length configuration for SME is very similar to that for SVE
so in order to allow reuse refactor the SVE configuration so that it takes
the vector type from the struct ctl_table. Since there's no dedicated space
for this we repurpose the extra1 field to store the vector type, this is
otherwise unused for integer sysctls.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20211210184133.320748-2-broonie@kernel.orgSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

arch/arm64/kernel/fpsimd.c

@@ -15,6 +15,7 @@
 #include <linux/compiler.h>
 #include <linux/cpu.h>
 #include <linux/cpu_pm.h>
+#include <linux/ctype.h>
 #include <linux/kernel.h>
 #include <linux/linkage.h>
 #include <linux/irqflags.h>
@@ -406,12 +407,13 @@ static unsigned int find_supported_vector_length(enum vec_type type,
 
 #if defined(CONFIG_ARM64_SVE) && defined(CONFIG_SYSCTL)
 
-static int sve_proc_do_default_vl(struct ctl_table *table, int write,
+static int vec_proc_do_default_vl(struct ctl_table *table, int write,
 				  void *buffer, size_t *lenp, loff_t *ppos)
 {
-	struct vl_info *info = &vl_info[ARM64_VEC_SVE];
+	struct vl_info *info = table->extra1;
+	enum vec_type type = info->type;
 	int ret;
-	int vl = get_sve_default_vl();
+	int vl = get_default_vl(type);
 	struct ctl_table tmp_table = {
 		.data = &vl,
 		.maxlen = sizeof(vl),
@@ -428,7 +430,7 @@ static int sve_proc_do_default_vl(struct ctl_table *table, int write,
 	if (!sve_vl_valid(vl))
 		return -EINVAL;
 
-	set_sve_default_vl(find_supported_vector_length(ARM64_VEC_SVE, vl));
+	set_default_vl(type, find_supported_vector_length(type, vl));
 	return 0;
 }
 
@@ -436,7 +438,8 @@ static struct ctl_table sve_default_vl_table[] = {
 	{
 		.procname	= "sve_default_vector_length",
 		.mode		= 0644,
-		.proc_handler	= sve_proc_do_default_vl,
+		.proc_handler	= vec_proc_do_default_vl,
+		.extra1		= &vl_info[ARM64_VEC_SVE],
 	},
 	{ }
 };
@@ -1107,7 +1110,7 @@ static void fpsimd_flush_thread_vl(enum vec_type type)
 		vl = get_default_vl(type);
 
 	if (WARN_ON(!sve_vl_valid(vl)))
-		vl = SVE_VL_MIN;
+		vl = vl_info[type].min_vl;
 
 	supported_vl = find_supported_vector_length(type, vl);
 	if (WARN_ON(supported_vl != vl))