Merge tag 'powerpc-4.15-8' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:
 "More than we'd like after rc8, but nothing very alarming either, just
  tying up loose ends before the release:

  Since we changed powernv to use cpufreq_get() from show_cpuinfo(), we
  see warnings with PREEMPT enabled. But the preempt_disable() in
  show_cpuinfo() doesn't actually prevent CPU hotplug as it suggests, so
  remove it.

  Two updates to the recently merged RFI flush code. Wire up the generic
  sysfs file to report the status, and add a debugfs file to allow
  enabling/disabling it at runtime.

  Two updates to xmon, one to add the RFI flush related fields to the
  paca dump, and another to not use hashed pointers in the paca dump.

  And one minor fix to add a missing include of linux/types.h in
  asm/hvcall.h, not seen to break the build in upstream, but correct
  anyway.

  Thanks to: Benjamin Herrenschmidt, Michal Suchanek, Nicholas Piggin"

* tag 'powerpc-4.15-8' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/pseries: include linux/types.h in asm/hvcall.h
  powerpc/64s: Allow control of RFI flush via debugfs
  powerpc/64s: Wire up cpu_show_meltdown()
  powerpc: Don't preempt_disable() in show_cpuinfo()
  powerpc/xmon: Don't print hashed pointers in paca dump
  powerpc/xmon: Add RFI flush related fields to paca dump

1 files changed, 38 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index 491be4179ddd..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>
@@ -901,4 +902,41 @@ void __init setup_rfi_flush(enum l1d_flush_type types, bool enable)
 	if (!no_rfi_flush)
 		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)
+		return sprintf(buf, "Mitigation: RFI Flush\n");
+
+	return sprintf(buf, "Vulnerable\n");
+}
 #endif /* CONFIG_PPC_BOOK3S_64 */