ARM: v7 setup function should invalidate L1 cache

All ARMv5 and older CPUs invalidate their caches in the early assembly
setup function, prior to enabling the MMU.  This is because the L1
cache should not contain any data relevant to the execution of the
kernel at this point; all data should have been flushed out to memory.

This requirement should also be true for ARMv6 and ARMv7 CPUs - indeed,
these typically do not search their caches when caching is disabled (as
it needs to be when the MMU is disabled) so this change should be safe.

ARMv7 allows there to be CPUs which search their caches while caching is
disabled, and it's permitted that the cache is uninitialised at boot;
for these, the architecture reference manual requires that an
implementation specific code sequence is used immediately after reset
to ensure that the cache is placed into a sane state.  Such
functionality is definitely outside the remit of the Linux kernel, and
must be done by the SoC's firmware before _any_ CPU gets to the Linux
kernel.

Changing the data cache clean+invalidate to a mere invalidate allows us
to get rid of a lot of platform specific hacks around this issue for
their secondary CPU bringup paths - some of which were buggy.

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Dinh Nguyen <dinguyen@opensource.altera.com>
Acked-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Tested-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Tested-by: Thierry Reding <treding@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Michal Simek <michal.simek@xilinx.com>
Tested-by: Wei Xu <xuwei5@hisilicon.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

diff --git a/arch/arm/mach-bcm/Makefile b/arch/arm/mach-bcm/Makefile
index 4c38674c73ecb15d92702ca58b4d0f95bf2888fe..54d274da7ccba181c8ede133a6138c597ad3fa1a 100644 (file)
--- a/arch/arm/mach-bcm/Makefile
+++ b/arch/arm/mach-bcm/Makefile
@@ -43,5 +43,5 @@ obj-$(CONFIG_ARCH_BCM_63XX)   := bcm63xx.o
 ifeq ($(CONFIG_ARCH_BRCMSTB),y)
 CFLAGS_platsmp-brcmstb.o       += -march=armv7-a
 obj-y                          += brcmstb.o
-obj-$(CONFIG_SMP)              += headsmp-brcmstb.o platsmp-brcmstb.o
+obj-$(CONFIG_SMP)              += platsmp-brcmstb.o
 endif

diff --git a/arch/arm/mach-bcm/brcmstb.h b/arch/arm/mach-bcm/brcmstb.h
deleted file mode 100644 (file)
index ec0c3d1..0000000
--- a/arch/arm/mach-bcm/brcmstb.h
+++ /dev/null
@@ -1,19 +0,0 @@
-/*
- * Copyright (C) 2013-2014 Broadcom Corporation
- *
- * 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 version 2.
- *
- * This program is distributed "as is" WITHOUT ANY WARRANTY of any
- * kind, whether express or implied; without even the implied warranty
- * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- */
-
-#ifndef __BRCMSTB_H__
-#define __BRCMSTB_H__
-
-void brcmstb_secondary_startup(void);
-
-#endif /* __BRCMSTB_H__ */

diff --git a/arch/arm/mach-bcm/headsmp-brcmstb.S b/arch/arm/mach-bcm/headsmp-brcmstb.S
deleted file mode 100644 (file)
index 199c1ea..0000000
--- a/arch/arm/mach-bcm/headsmp-brcmstb.S
+++ /dev/null
@@ -1,33 +0,0 @@
-/*
- * SMP boot code for secondary CPUs
- * Based on arch/arm/mach-tegra/headsmp.S
- *
- * Copyright (C) 2010 NVIDIA, Inc.
- * Copyright (C) 2013-2014 Broadcom Corporation
- *
- * 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 version 2.
- *
- * This program is distributed "as is" WITHOUT ANY WARRANTY of any
- * kind, whether express or implied; without even the implied warranty
- * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- */
-
-#include <asm/assembler.h>
-#include <linux/linkage.h>
-#include <linux/init.h>
-
-        .section ".text.head", "ax"
-
-ENTRY(brcmstb_secondary_startup)
-        /*
-         * Ensure CPU is in a sane state by disabling all IRQs and switching
-         * into SVC mode.
-         */
-        setmode        PSR_I_BIT | PSR_F_BIT | SVC_MODE, r0
-
-        bl      v7_invalidate_l1
-        b       secondary_startup
-ENDPROC(brcmstb_secondary_startup)

diff --git a/arch/arm/mach-bcm/platsmp-brcmstb.c b/arch/arm/mach-bcm/platsmp-brcmstb.c
index e209e6fc7cafa553fa56ec5f0f2b845d447a0ff7..44d6bddf7a4e788044da329ce79f4a66ae6b07ed 100644 (file)
--- a/arch/arm/mach-bcm/platsmp-brcmstb.c
+++ b/arch/arm/mach-bcm/platsmp-brcmstb.c
@@ -30,8 +30,6 @@
 #include <asm/mach-types.h>
 #include <asm/smp_plat.h>
 
-#include "brcmstb.h"
-
 enum {
        ZONE_MAN_CLKEN_MASK             = BIT(0),
        ZONE_MAN_RESET_CNTL_MASK        = BIT(1),
@@ -153,7 +151,7 @@ static void brcmstb_cpu_boot(u32 cpu)
         * Set the reset vector to point to the secondary_startup
         * routine
         */
-       cpu_set_boot_addr(cpu, virt_to_phys(brcmstb_secondary_startup));
+       cpu_set_boot_addr(cpu, virt_to_phys(secondary_startup));
 
        /* Unhalt the cpu */
        cpu_rst_cfg_set(cpu, 0);

diff --git a/arch/arm/mach-berlin/headsmp.S b/arch/arm/mach-berlin/headsmp.S
index 4a4c56a58ad351f03a935b7e9b9938740ff049bf..dc82a3486b05e6b208c37fe8f93707d9388b06db 100644 (file)
--- a/arch/arm/mach-berlin/headsmp.S
+++ b/arch/arm/mach-berlin/headsmp.S
@@ -12,12 +12,6 @@
 #include <linux/init.h>
 #include <asm/assembler.h>
 
-ENTRY(berlin_secondary_startup)
- ARM_BE8(setend be)
-       bl      v7_invalidate_l1
-       b       secondary_startup
-ENDPROC(berlin_secondary_startup)
-
 /*
  * If the following instruction is set in the reset exception vector, CPUs
  * will fetch the value of the software reset address vector when being

diff --git a/arch/arm/mach-berlin/platsmp.c b/arch/arm/mach-berlin/platsmp.c
index 702e7982015abcf81ba68cde339bfa2512ad8abc..34a3753e73564ed99cf92bbaee7c94ed5a869acb 100644 (file)
--- a/arch/arm/mach-berlin/platsmp.c
+++ b/arch/arm/mach-berlin/platsmp.c
@@ -22,7 +22,6 @@
 #define RESET_VECT             0x00
 #define SW_RESET_ADDR          0x94
 
-extern void berlin_secondary_startup(void);
 extern u32 boot_inst;
 
 static void __iomem *cpu_ctrl;
@@ -85,7 +84,7 @@ static void __init berlin_smp_prepare_cpus(unsigned int max_cpus)
         * Write the secondary startup address into the SW reset address
         * vector. This is used by boot_inst.
         */
-       writel(virt_to_phys(berlin_secondary_startup), vectors_base + SW_RESET_ADDR);
+       writel(virt_to_phys(secondary_startup), vectors_base + SW_RESET_ADDR);
 
        iounmap(vectors_base);
 unmap_scu:

diff --git a/arch/arm/mach-hisi/Makefile b/arch/arm/mach-hisi/Makefile
index 6b7b3033de0bcfa0d22b4b5be681953354fa83d1..659db1933ed3619e987dc8c017ab8ea215762eb3 100644 (file)
--- a/arch/arm/mach-hisi/Makefile
+++ b/arch/arm/mach-hisi/Makefile
@@ -6,4 +6,4 @@ CFLAGS_platmcpm.o       := -march=armv7-a
 
 obj-y  += hisilicon.o
 obj-$(CONFIG_MCPM)             += platmcpm.o
-obj-$(CONFIG_SMP)              += platsmp.o hotplug.o headsmp.o
+obj-$(CONFIG_SMP)              += platsmp.o hotplug.o

diff --git a/arch/arm/mach-hisi/core.h b/arch/arm/mach-hisi/core.h
index 92a682d8e93943e3b1aa0bb813119b8451737597..c7648ef1825c70283b3a8d1e123176cb71dafd22 100644 (file)
--- a/arch/arm/mach-hisi/core.h
+++ b/arch/arm/mach-hisi/core.h
@@ -12,7 +12,6 @@ extern void hi3xxx_cpu_die(unsigned int cpu);
 extern int hi3xxx_cpu_kill(unsigned int cpu);
 extern void hi3xxx_set_cpu(int cpu, bool enable);
 
-extern void hisi_secondary_startup(void);
 extern struct smp_operations hix5hd2_smp_ops;
 extern void hix5hd2_set_cpu(int cpu, bool enable);
 extern void hix5hd2_cpu_die(unsigned int cpu);

diff --cc arch/arm/mach-hisi/headsmp.S
Simple merge

diff --cc arch/arm/mach-hisi/platsmp.c
Simple merge

diff --cc arch/arm/mach-imx/headsmp.S
Simple merge

diff --cc arch/arm/mach-mvebu/headsmp-a9.S
Simple merge

diff --cc arch/arm/mach-prima2/headsmp.S
Simple merge

diff --cc arch/arm/mach-rockchip/core.h
Simple merge

diff --cc arch/arm/mach-rockchip/headsmp.S
Simple merge

diff --cc arch/arm/mach-rockchip/platsmp.c
Simple merge

diff --cc arch/arm/mach-shmobile/common.h
Simple merge

diff --cc arch/arm/mach-shmobile/headsmp-scu.S
Simple merge

diff --cc arch/arm/mach-shmobile/headsmp.S
Simple merge

diff --cc arch/arm/mach-shmobile/platsmp-apmu.c
Simple merge

diff --cc arch/arm/mach-socfpga/core.h
Simple merge

diff --cc arch/arm/mach-socfpga/headsmp.S
Simple merge

diff --cc arch/arm/mach-socfpga/platsmp.c
Simple merge

diff --cc arch/arm/mach-tegra/Makefile
Simple merge

diff --cc arch/arm/mach-tegra/headsmp.S
Simple merge

diff --cc arch/arm/mach-tegra/reset.c
Simple merge

diff --cc arch/arm/mach-tegra/reset.h
Simple merge

diff --cc arch/arm/mach-zynq/common.h
Simple merge

diff --cc arch/arm/mach-zynq/headsmp.S
Simple merge

diff --cc arch/arm/mach-zynq/platsmp.c
Simple merge

diff --cc arch/arm/mm/proc-v7.S
Simple merge