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authorMichael Ellerman <mpe@ellerman.id.au>2018-01-16 22:17:18 +1100
committerMichael Ellerman <mpe@ellerman.id.au>2018-01-17 23:30:21 +1100
commit236003e6b5443c45c18e613d2b0d776a9f87540e (patch)
tree9bef6af7bd651cff92484097cbc43cebbeee253a /arch/powerpc
parentfd6e440f20b1a4304553775fc55938848ff617c9 (diff)
powerpc/64s: Allow control of RFI flush via debugfs
Expose the state of the RFI flush (enabled/disabled) via debugfs, and allow it to be enabled/disabled at runtime. eg: $ cat /sys/kernel/debug/powerpc/rfi_flush 1 $ echo 0 > /sys/kernel/debug/powerpc/rfi_flush $ cat /sys/kernel/debug/powerpc/rfi_flush 0 Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Diffstat (limited to 'arch/powerpc')
-rw-r--r--arch/powerpc/kernel/setup_64.c30
1 files changed, 30 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index 624d2a62d05d..e67413f4a8f0 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -38,6 +38,7 @@
#include <linux/memory.h>
#include <linux/nmi.h>
+#include <asm/debugfs.h>
#include <asm/io.h>
#include <asm/kdump.h>
#include <asm/prom.h>
@@ -902,6 +903,35 @@ void __init setup_rfi_flush(enum l1d_flush_type types, bool enable)
rfi_flush_enable(enable);
}
+#ifdef CONFIG_DEBUG_FS
+static int rfi_flush_set(void *data, u64 val)
+{
+ if (val == 1)
+ rfi_flush_enable(true);
+ else if (val == 0)
+ rfi_flush_enable(false);
+ else
+ return -EINVAL;
+
+ return 0;
+}
+
+static int rfi_flush_get(void *data, u64 *val)
+{
+ *val = rfi_flush ? 1 : 0;
+ return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(fops_rfi_flush, rfi_flush_get, rfi_flush_set, "%llu\n");
+
+static __init int rfi_flush_debugfs_init(void)
+{
+ debugfs_create_file("rfi_flush", 0600, powerpc_debugfs_root, NULL, &fops_rfi_flush);
+ return 0;
+}
+device_initcall(rfi_flush_debugfs_init);
+#endif
+
ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr, char *buf)
{
if (rfi_flush)