Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/arm/plat-versatile/Kconfig b/arch/arm/plat-versatile/Kconfig
index 98b9b8e..748238f 100644
--- a/arch/arm/plat-versatile/Kconfig
+++ b/arch/arm/plat-versatile/Kconfig
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
if PLAT_VERSATILE
config PLAT_VERSATILE_SCHED_CLOCK
diff --git a/arch/arm/plat-versatile/Makefile b/arch/arm/plat-versatile/Makefile
index bff3ba8..e856f0a 100644
--- a/arch/arm/plat-versatile/Makefile
+++ b/arch/arm/plat-versatile/Makefile
@@ -1,4 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0-only
ccflags-$(CONFIG_ARCH_MULTIPLATFORM) := -I$(srctree)/$(src)/include
obj-$(CONFIG_PLAT_VERSATILE_SCHED_CLOCK) += sched-clock.o
obj-$(CONFIG_SMP) += headsmp.o platsmp.o
+obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o
diff --git a/arch/arm/plat-versatile/headsmp.S b/arch/arm/plat-versatile/headsmp.S
index 40f27e5..09d9fc3 100644
--- a/arch/arm/plat-versatile/headsmp.S
+++ b/arch/arm/plat-versatile/headsmp.S
@@ -1,12 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
/*
* linux/arch/arm/plat-versatile/headsmp.S
*
* Copyright (c) 2003 ARM Limited
* All Rights Reserved
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
*/
#include <linux/linkage.h>
#include <linux/init.h>
@@ -37,5 +34,5 @@
.align
1: .long .
- .long pen_release
+ .long versatile_cpu_release
ENDPROC(versatile_secondary_startup)
diff --git a/arch/arm/plat-versatile/hotplug.c b/arch/arm/plat-versatile/hotplug.c
new file mode 100644
index 0000000..2e9dca3
--- /dev/null
+++ b/arch/arm/plat-versatile/hotplug.c
@@ -0,0 +1,102 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2002 ARM Ltd.
+ * All Rights Reserved
+ *
+ * This hotplug implementation is _specific_ to the situation found on
+ * ARM development platforms where there is _no_ possibility of actually
+ * taking a CPU offline, resetting it, or otherwise. Real platforms must
+ * NOT copy this code.
+ */
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/smp.h>
+
+#include <asm/smp_plat.h>
+#include <asm/cp15.h>
+
+#include <plat/platsmp.h>
+
+static inline void versatile_immitation_enter_lowpower(unsigned int actrl_mask)
+{
+ unsigned int v;
+
+ asm volatile(
+ "mcr p15, 0, %1, c7, c5, 0\n"
+ " mcr p15, 0, %1, c7, c10, 4\n"
+ /*
+ * Turn off coherency
+ */
+ " mrc p15, 0, %0, c1, c0, 1\n"
+ " bic %0, %0, %3\n"
+ " mcr p15, 0, %0, c1, c0, 1\n"
+ " mrc p15, 0, %0, c1, c0, 0\n"
+ " bic %0, %0, %2\n"
+ " mcr p15, 0, %0, c1, c0, 0\n"
+ : "=&r" (v)
+ : "r" (0), "Ir" (CR_C), "Ir" (actrl_mask)
+ : "cc");
+}
+
+static inline void versatile_immitation_leave_lowpower(unsigned int actrl_mask)
+{
+ unsigned int v;
+
+ asm volatile(
+ "mrc p15, 0, %0, c1, c0, 0\n"
+ " orr %0, %0, %1\n"
+ " mcr p15, 0, %0, c1, c0, 0\n"
+ " mrc p15, 0, %0, c1, c0, 1\n"
+ " orr %0, %0, %2\n"
+ " mcr p15, 0, %0, c1, c0, 1\n"
+ : "=&r" (v)
+ : "Ir" (CR_C), "Ir" (actrl_mask)
+ : "cc");
+}
+
+static inline void versatile_immitation_do_lowpower(unsigned int cpu, int *spurious)
+{
+ /*
+ * there is no power-control hardware on this platform, so all
+ * we can do is put the core into WFI; this is safe as the calling
+ * code will have already disabled interrupts.
+ *
+ * This code should not be used outside Versatile platforms.
+ */
+ for (;;) {
+ wfi();
+
+ if (versatile_cpu_release == cpu_logical_map(cpu)) {
+ /*
+ * OK, proper wakeup, we're done
+ */
+ break;
+ }
+
+ /*
+ * Getting here, means that we have come out of WFI without
+ * having been woken up - this shouldn't happen
+ *
+ * Just note it happening - when we're woken, we can report
+ * its occurrence.
+ */
+ (*spurious)++;
+ }
+}
+
+/*
+ * platform-specific code to shutdown a CPU.
+ * This code supports immitation-style CPU hotplug for Versatile/Realview/
+ * Versatile Express platforms that are unable to do real CPU hotplug.
+ */
+void versatile_immitation_cpu_die(unsigned int cpu, unsigned int actrl_mask)
+{
+ int spurious = 0;
+
+ versatile_immitation_enter_lowpower(actrl_mask);
+ versatile_immitation_do_lowpower(cpu, &spurious);
+ versatile_immitation_leave_lowpower(actrl_mask);
+
+ if (spurious)
+ pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious);
+}
diff --git a/arch/arm/plat-versatile/include/plat/platsmp.h b/arch/arm/plat-versatile/include/plat/platsmp.h
index 50fb830..500605f 100644
--- a/arch/arm/plat-versatile/include/plat/platsmp.h
+++ b/arch/arm/plat-versatile/include/plat/platsmp.h
@@ -1,14 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
/*
* linux/arch/arm/plat-versatile/include/plat/platsmp.h
*
* Copyright (C) 2011 ARM Ltd.
* All Rights Reserved
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
*/
+extern volatile int versatile_cpu_release;
extern void versatile_secondary_startup(void);
extern void versatile_secondary_init(unsigned int cpu);
extern int versatile_boot_secondary(unsigned int cpu, struct task_struct *idle);
+void versatile_immitation_cpu_die(unsigned int cpu, unsigned int actrl_mask);
diff --git a/arch/arm/plat-versatile/platsmp.c b/arch/arm/plat-versatile/platsmp.c
index c236651..3567296 100644
--- a/arch/arm/plat-versatile/platsmp.c
+++ b/arch/arm/plat-versatile/platsmp.c
@@ -1,12 +1,14 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* linux/arch/arm/plat-versatile/platsmp.c
*
* Copyright (C) 2002 ARM Ltd.
* All Rights Reserved
*
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
+ * This code is specific to the hardware found on ARM Realview and
+ * Versatile Express platforms where the CPUs are unable to be individually
+ * woken, and where there is no way to hot-unplug CPUs. Real platforms
+ * should not copy this code.
*/
#include <linux/init.h>
#include <linux/errno.h>
@@ -21,18 +23,32 @@
#include <plat/platsmp.h>
/*
- * Write pen_release in a way that is guaranteed to be visible to all
- * observers, irrespective of whether they're taking part in coherency
+ * versatile_cpu_release controls the release of CPUs from the holding
+ * pen in headsmp.S, which exists because we are not always able to
+ * control the release of individual CPUs from the board firmware.
+ * Production platforms do not need this.
+ */
+volatile int versatile_cpu_release = -1;
+
+/*
+ * Write versatile_cpu_release in a way that is guaranteed to be visible to
+ * all observers, irrespective of whether they're taking part in coherency
* or not. This is necessary for the hotplug code to work reliably.
*/
-static void write_pen_release(int val)
+static void versatile_write_cpu_release(int val)
{
- pen_release = val;
+ versatile_cpu_release = val;
smp_wmb();
- sync_cache_w(&pen_release);
+ sync_cache_w(&versatile_cpu_release);
}
-static DEFINE_SPINLOCK(boot_lock);
+/*
+ * versatile_lock exists to avoid running the loops_per_jiffy delay loop
+ * calibrations on the secondary CPU while the requesting CPU is using
+ * the limited-bandwidth bus - which affects the calibration value.
+ * Production platforms do not need this.
+ */
+static DEFINE_RAW_SPINLOCK(versatile_lock);
void versatile_secondary_init(unsigned int cpu)
{
@@ -40,13 +56,13 @@
* let the primary processor know we're out of the
* pen, then head off into the C entry point
*/
- write_pen_release(-1);
+ versatile_write_cpu_release(-1);
/*
* Synchronise with the boot thread.
*/
- spin_lock(&boot_lock);
- spin_unlock(&boot_lock);
+ raw_spin_lock(&versatile_lock);
+ raw_spin_unlock(&versatile_lock);
}
int versatile_boot_secondary(unsigned int cpu, struct task_struct *idle)
@@ -57,7 +73,7 @@
* Set synchronisation state between this boot processor
* and the secondary one
*/
- spin_lock(&boot_lock);
+ raw_spin_lock(&versatile_lock);
/*
* This is really belt and braces; we hold unintended secondary
@@ -65,7 +81,7 @@
* since we haven't sent them a soft interrupt, they shouldn't
* be there.
*/
- write_pen_release(cpu_logical_map(cpu));
+ versatile_write_cpu_release(cpu_logical_map(cpu));
/*
* Send the secondary CPU a soft interrupt, thereby causing
@@ -77,7 +93,7 @@
timeout = jiffies + (1 * HZ);
while (time_before(jiffies, timeout)) {
smp_rmb();
- if (pen_release == -1)
+ if (versatile_cpu_release == -1)
break;
udelay(10);
@@ -87,7 +103,7 @@
* now the secondary core is starting up let it run its
* calibrations, then wait for it to finish
*/
- spin_unlock(&boot_lock);
+ raw_spin_unlock(&versatile_lock);
- return pen_release != -1 ? -ENOSYS : 0;
+ return versatile_cpu_release != -1 ? -ENOSYS : 0;
}
diff --git a/arch/arm/plat-versatile/sched-clock.c b/arch/arm/plat-versatile/sched-clock.c
index c966ae9..ecb7913 100644
--- a/arch/arm/plat-versatile/sched-clock.c
+++ b/arch/arm/plat-versatile/sched-clock.c
@@ -1,22 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/*
* linux/arch/arm/plat-versatile/sched-clock.c
*
* Copyright (C) 1999 - 2003 ARM Limited
* Copyright (C) 2000 Deep Blue Solutions Ltd
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/kernel.h>
#include <linux/io.h>