Commit d7f864be authored by Catalin Marinas's avatar Catalin Marinas
Browse files

ARMv7: Add support for the ThumbEE state saving/restoring



This patch adds the detection and handling of the ThumbEE extension on
ARMv7 CPUs.
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 05dda977
......@@ -22,6 +22,7 @@ obj-$(CONFIG_KEXEC) += machine_kexec.o relocate_kernel.o
obj-$(CONFIG_KPROBES) += kprobes.o kprobes-decode.o
obj-$(CONFIG_ATAGS_PROC) += atags.o
obj-$(CONFIG_OABI_COMPAT) += sys_oabi-compat.o
obj-$(CONFIG_ARM_THUMBEE) += thumbee.o
obj-$(CONFIG_CRUNCH) += crunch.o crunch-bits.o
AFLAGS_crunch-bits.o := -Wa,-mcpu=ep9312
......
......@@ -58,6 +58,9 @@ int main(void)
DEFINE(TI_TP_VALUE, offsetof(struct thread_info, tp_value));
DEFINE(TI_FPSTATE, offsetof(struct thread_info, fpstate));
DEFINE(TI_VFPSTATE, offsetof(struct thread_info, vfpstate));
#ifdef CONFIG_ARM_THUMBEE
DEFINE(TI_THUMBEE_STATE, offsetof(struct thread_info, thumbee_state));
#endif
#ifdef CONFIG_IWMMXT
DEFINE(TI_IWMMXT_STATE, offsetof(struct thread_info, fpstate.iwmmxt));
#endif
......
/*
* arch/arm/kernel/thumbee.c
*
* Copyright (C) 2008 ARM Limited
*
* 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 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/init.h>
#include <asm/thread_notify.h>
/*
* Access to the ThumbEE Handler Base register
*/
static inline unsigned long teehbr_read()
{
unsigned long v;
asm("mrc p14, 6, %0, c1, c0, 0\n" : "=r" (v));
return v;
}
static inline void teehbr_write(unsigned long v)
{
asm("mcr p14, 6, %0, c1, c0, 0\n" : : "r" (v));
}
static int thumbee_notifier(struct notifier_block *self, unsigned long cmd, void *t)
{
struct thread_info *thread = t;
switch (cmd) {
case THREAD_NOTIFY_FLUSH:
thread->thumbee_state = 0;
break;
case THREAD_NOTIFY_SWITCH:
current_thread_info()->thumbee_state = teehbr_read();
teehbr_write(thread->thumbee_state);
break;
}
return NOTIFY_DONE;
}
static struct notifier_block thumbee_notifier_block = {
.notifier_call = thumbee_notifier,
};
static int __init thumbee_init(void)
{
unsigned long pfr0;
unsigned int cpu_arch = cpu_architecture();
if (cpu_arch < CPU_ARCH_ARMv7)
return 0;
/* processor feature register 0 */
asm("mrc p15, 0, %0, c0, c1, 0\n" : "=r" (pfr0));
if ((pfr0 & 0x0000f000) != 0x00001000)
return 0;
printk(KERN_INFO "ThumbEE CPU extension supported.\n");
elf_hwcap |= HWCAP_THUMBEE;
thread_register_notifier(&thumbee_notifier_block);
return 0;
}
late_initcall(thumbee_init);
......@@ -572,6 +572,13 @@ config ARM_THUMB
If you don't know what this all is, saying Y is a safe choice.
config ARM_THUMBEE
bool "Enable ThumbEE CPU extension"
depends on CPU_V7
help
Say Y here if you have a CPU with the ThumbEE extension and code to
make use of it. Say N for code that can run on CPUs without ThumbEE.
config CPU_BIG_ENDIAN
bool "Build big-endian kernel"
depends on ARCH_SUPPORTS_BIG_ENDIAN
......
......@@ -15,6 +15,7 @@
#define HWCAP_JAVA 256
#define HWCAP_IWMMXT 512
#define HWCAP_CRUNCH 1024
#define HWCAP_THUMBEE 2048
#if defined(__KERNEL__) && !defined(__ASSEMBLY__)
/*
......
......@@ -62,6 +62,9 @@ struct thread_info {
struct crunch_state crunchstate;
union fp_state fpstate __attribute__((aligned(8)));
union vfp_state vfpstate;
#ifdef CONFIG_ARM_THUMBEE
unsigned long thumbee_state; /* ThumbEE Handler Base register */
#endif
struct restart_block restart_block;
};
......
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