From: michal.simek@xilinx.com (Michal Simek)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v3 11/12] arm: zynq: Add hotplug support
Date: Thu, 28 Mar 2013 17:38:11 +0100 [thread overview]
Message-ID: <51507fc25e8f50378e7e909b083644c83f821ac4.1364488495.git.michal.simek@xilinx.com> (raw)
In-Reply-To: <1364488692-18709-1-git-send-email-michal.simek@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
---
v3: Use zynq_ prefix for all functions
v2: Change platform_cpu_die name function to zynq_platform_cpu_dio
Fix header
Add cpu compilation flags to be able to build on V6 too
---
arch/arm/mach-zynq/Makefile | 3 ++
arch/arm/mach-zynq/common.h | 3 ++
arch/arm/mach-zynq/hotplug.c | 104 ++++++++++++++++++++++++++++++++++++++++++
arch/arm/mach-zynq/platsmp.c | 3 ++
4 files changed, 113 insertions(+)
create mode 100644 arch/arm/mach-zynq/hotplug.c
diff --git a/arch/arm/mach-zynq/Makefile b/arch/arm/mach-zynq/Makefile
index b595d22..1b25d92 100644
--- a/arch/arm/mach-zynq/Makefile
+++ b/arch/arm/mach-zynq/Makefile
@@ -4,4 +4,7 @@
# Common support
obj-y := common.o slcr.o
+CFLAGS_REMOVE_hotplug.o =-march=armv6k
+CFLAGS_hotplug.o =-Wa,-march=armv7-a -mcpu=cortex-a9
+obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o
obj-$(CONFIG_SMP) += headsmp.o platsmp.o
diff --git a/arch/arm/mach-zynq/common.h b/arch/arm/mach-zynq/common.h
index fd308f8..fbbd0e2 100644
--- a/arch/arm/mach-zynq/common.h
+++ b/arch/arm/mach-zynq/common.h
@@ -34,4 +34,7 @@ extern struct smp_operations zynq_smp_ops __initdata;
extern void __iomem *zynq_slcr_base;
extern void __iomem *zynq_scu_base;
+/* Hotplug */
+extern void zynq_platform_cpu_die(unsigned int cpu);
+
#endif
diff --git a/arch/arm/mach-zynq/hotplug.c b/arch/arm/mach-zynq/hotplug.c
new file mode 100644
index 0000000..c89672b
--- /dev/null
+++ b/arch/arm/mach-zynq/hotplug.c
@@ -0,0 +1,104 @@
+/*
+ * Copyright (C) 2012-2013 Xilinx
+ *
+ * based on linux/arch/arm/mach-realview/hotplug.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.
+ */
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/smp.h>
+
+#include <asm/cacheflush.h>
+#include <asm/cp15.h>
+#include "common.h"
+
+static inline void zynq_cpu_enter_lowpower(void)
+{
+ unsigned int v;
+
+ flush_cache_all();
+ asm volatile(
+ " mcr p15, 0, %1, c7, c5, 0\n"
+ " dsb\n"
+ /*
+ * Turn off coherency
+ */
+ " mrc p15, 0, %0, c1, c0, 1\n"
+ " bic %0, %0, #0x40\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)
+ : "cc");
+}
+
+static inline void zynq_cpu_leave_lowpower(void)
+{
+ 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, #0x40\n"
+ " mcr p15, 0, %0, c1, c0, 1\n"
+ : "=&r" (v)
+ : "Ir" (CR_C)
+ : "cc");
+}
+
+static inline void zynq_platform_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
+ */
+ for (;;) {
+ dsb();
+ wfi();
+
+ /*
+ * 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
+ *
+ * Called with IRQs disabled
+ */
+void zynq_platform_cpu_die(unsigned int cpu)
+{
+ int spurious = 0;
+
+ /*
+ * we're ready for shutdown now, so do it
+ */
+ zynq_cpu_enter_lowpower();
+ zynq_platform_do_lowpower(cpu, &spurious);
+
+ /*
+ * bring this CPU back into the world of cache
+ * coherency, and then restore interrupts
+ */
+ zynq_cpu_leave_lowpower();
+
+ if (spurious)
+ pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious);
+}
diff --git a/arch/arm/mach-zynq/platsmp.c b/arch/arm/mach-zynq/platsmp.c
index cdfd888..3072cbd 100644
--- a/arch/arm/mach-zynq/platsmp.c
+++ b/arch/arm/mach-zynq/platsmp.c
@@ -146,4 +146,7 @@ struct smp_operations zynq_smp_ops __initdata = {
.smp_prepare_cpus = zynq_smp_prepare_cpus,
.smp_secondary_init = zynq_secondary_init,
.smp_boot_secondary = zynq_boot_secondary,
+#ifdef CONFIG_HOTPLUG_CPU
+ .cpu_die = zynq_platform_cpu_die,
+#endif
};
--
1.7.9.7
next prev parent reply other threads:[~2013-03-28 16:38 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-28 16:38 Zynq core changes v3 Michal Simek
2013-03-28 16:38 ` [PATCH v3 01/12] arm: zynq: Use standard timer binding Michal Simek
2013-03-28 16:38 ` [PATCH v3 02/12] arm: zynq: Move timer to clocksource interface Michal Simek
2013-03-28 16:38 ` [PATCH v3 03/12] arm: zynq: Do not use xilinx specific function names Michal Simek
2013-03-28 16:38 ` [PATCH v3 04/12] arm: zynq: Move timer to generic location Michal Simek
2013-03-28 16:38 ` [PATCH v3 05/12] arm: zynq: Load scu baseaddress at run time Michal Simek
2013-03-28 16:38 ` [PATCH v3 06/12] arm: zynq: Move slcr initialization to separate file Michal Simek
2013-03-28 16:38 ` [PATCH v3 07/12] arm: zynq: Add support for system reset Michal Simek
2013-03-28 16:38 ` [PATCH v3 08/12] arm: zynq: Add support for pmu Michal Simek
2013-03-28 16:38 ` [PATCH v3 09/12] arm: zynq: Add smp_twd timer Michal Simek
2013-03-28 16:38 ` [PATCH v3 10/12] arm: zynq: Add smp support Michal Simek
2013-03-28 16:38 ` Michal Simek [this message]
2013-03-28 16:38 ` [PATCH v3 12/12] arm: zynq: Get rid of xilinx function prefix Michal Simek
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=51507fc25e8f50378e7e909b083644c83f821ac4.1364488495.git.michal.simek@xilinx.com \
--to=michal.simek@xilinx.com \
--cc=linux-arm-kernel@lists.infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.