[PATCH 4.14 087/109] ARM: bugs: hook processor bug checking into SMP and suspend paths

Greg Kroah-Hartman
2018-10-16T17:21:05Z

From: Russell King <rmk+kernel@armlinux.org.uk>

Commit 26602161b5ba795928a5a719fe1d5d9f2ab5c3ef upstream.

Check for CPU bugs when secondary processors are being brought online,
and also when CPUs are resuming from a low power mode. This gives an
opportunity to check that processor specific bug workarounds are
correctly enabled for all paths that a CPU re-enters the kernel.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/arm/include/asm/bugs.h | 2 ++
arch/arm/kernel/bugs.c | 5 +++++
arch/arm/kernel/smp.c | 4 ++++
arch/arm/kernel/suspend.c | 2 ++
4 files changed, 13 insertions(+)

--- a/arch/arm/include/asm/bugs.h
+++ b/arch/arm/include/asm/bugs.h
@@ -14,8 +14,10 @@ extern void check_writebuffer_bugs(void)

#ifdef CONFIG_MMU
extern void check_bugs(void);
+extern void check_other_bugs(void);
#else
#define check_bugs() do { } while (0)
+#define check_other_bugs() do { } while (0)
#endif

#endif
--- a/arch/arm/kernel/bugs.c
+++ b/arch/arm/kernel/bugs.c
@@ -3,7 +3,12 @@
#include <asm/bugs.h>
#include <asm/proc-fns.h>

+void check_other_bugs(void)
+{
+}
+
void __init check_bugs(void)
{
check_writebuffer_bugs();
+ check_other_bugs();
}
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -31,6 +31,7 @@
#include <linux/irq_work.h>

#include <linux/atomic.h>
+#include <asm/bugs.h>
#include <asm/smp.h>
#include <asm/cacheflush.h>
#include <asm/cpu.h>
@@ -402,6 +403,9 @@ asmlinkage void secondary_start_kernel(v
* before we continue - which happens after __cpu_up returns.
*/
set_cpu_online(cpu, true);
+
+ check_other_bugs();
+
complete(&cpu_running);

local_irq_enable();
--- a/arch/arm/kernel/suspend.c
+++ b/arch/arm/kernel/suspend.c
@@ -3,6 +3,7 @@
#include <linux/slab.h>
#include <linux/mm_types.h>

+#include <asm/bugs.h>
#include <asm/cacheflush.h>
#include <asm/idmap.h>
#include <asm/pgalloc.h>
@@ -36,6 +37,7 @@ int cpu_suspend(unsigned long arg, int (
cpu_switch_mm(mm->pgd, mm);
local_flush_bp_all();
local_flush_tlb_all();
+ check_other_bugs();
}

return ret;